diff --git a/swh/storage/in_memory.py b/swh/storage/in_memory.py
index 0061ce0e..790998dd 100644
--- a/swh/storage/in_memory.py
+++ b/swh/storage/in_memory.py
@@ -1,1782 +1,1814 @@
 # Copyright (C) 2015-2019  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import re
 import bisect
 import dateutil
 import collections
 import copy
 import datetime
 import itertools
 import random
 
 from collections import defaultdict
 from datetime import timedelta
-from typing import Any, Dict, Mapping
+from typing import Any, Dict, Mapping, Optional
 
 import attr
 
 from swh.model.model import \
     Content, Directory, Revision, Release, Snapshot, OriginVisit, Origin
 from swh.model.hashutil import DEFAULT_ALGORITHMS
 from swh.objstorage import get_objstorage
 from swh.objstorage.exc import ObjNotFoundError
 
 from .storage import get_journal_writer
 from .converters import origin_url_to_sha1
 
 # Max block size of contents to return
 BULK_BLOCK_CONTENT_LEN_MAX = 10000
 
 
 def now():
     return datetime.datetime.now(tz=datetime.timezone.utc)
 
 
 class Storage:
     def __init__(self, journal_writer=None):
         self._contents = {}
         self._content_indexes = defaultdict(lambda: defaultdict(set))
         self._skipped_contents = {}
         self._skipped_content_indexes = defaultdict(lambda: defaultdict(set))
 
         self.reset()
 
         if journal_writer:
             self.journal_writer = get_journal_writer(**journal_writer)
         else:
             self.journal_writer = None
 
     def reset(self):
         self._directories = {}
         self._revisions = {}
         self._releases = {}
         self._snapshots = {}
         self._origins = {}
         self._origins_by_id = []
         self._origins_by_sha1 = {}
         self._origin_visits = {}
         self._persons = []
         self._origin_metadata = defaultdict(list)
         self._tools = {}
         self._metadata_providers = {}
         self._objects = defaultdict(list)
 
         # ideally we would want a skip list for both fast inserts and searches
         self._sorted_sha1s = []
 
         self.objstorage = get_objstorage('memory', {})
 
     def check_config(self, *, check_write):
         """Check that the storage is configured and ready to go."""
         return True
 
     def _content_add(self, contents, with_data):
         content_with_data = []
         content_without_data = []
         for content in contents:
             if content.status is None:
                 content.status = 'visible'
             if content.length is None:
                 content.length = -1
             if content.status != 'absent':
                 if self._content_key(content) not in self._contents:
                     content_with_data.append(content)
             else:
                 if self._content_key(content) not in self._skipped_contents:
                     content_without_data.append(content)
 
         if self.journal_writer:
             for content in content_with_data:
                 content = attr.evolve(content, data=None)
                 self.journal_writer.write_addition('content', content)
             for content in content_without_data:
                 self.journal_writer.write_addition('content', content)
 
         count_content_added, count_content_bytes_added = \
             self._content_add_present(content_with_data, with_data)
 
         count_skipped_content_added = self._content_add_absent(
             content_without_data
         )
 
         summary = {
             'content:add': count_content_added,
             'skipped_content:add': count_skipped_content_added,
         }
 
         if with_data:
             summary['content:add:bytes'] = count_content_bytes_added
 
         return summary
 
     def _content_add_present(self, contents, with_data):
         count_content_added = 0
         count_content_bytes_added = 0
         for content in contents:
             key = self._content_key(content)
             if key in self._contents:
                 continue
             for algorithm in DEFAULT_ALGORITHMS:
                 hash_ = content.get_hash(algorithm)
                 if hash_ in self._content_indexes[algorithm]\
                    and (algorithm not in {'blake2s256', 'sha256'}):
                     from . import HashCollision
                     raise HashCollision(algorithm, hash_, key)
             for algorithm in DEFAULT_ALGORITHMS:
                 hash_ = content.get_hash(algorithm)
                 self._content_indexes[algorithm][hash_].add(key)
             self._objects[content.sha1_git].append(
                 ('content', content.sha1))
             self._contents[key] = content
             bisect.insort(self._sorted_sha1s, content.sha1)
             count_content_added += 1
             if with_data:
                 content_data = self._contents[key].data
                 self._contents[key] = attr.evolve(
                     self._contents[key],
                     data=None)
                 count_content_bytes_added += len(content_data)
                 self.objstorage.add(content_data, content.sha1)
 
         return (count_content_added, count_content_bytes_added)
 
     def _content_add_absent(self, contents):
         count = 0
         skipped_content_missing = self.skipped_content_missing(contents)
         for content in skipped_content_missing:
             key = self._content_key(content)
             for algo in DEFAULT_ALGORITHMS:
                 self._skipped_content_indexes[algo][content.get_hash(algo)] \
                     .add(key)
             self._skipped_contents[key] = content
             count += 1
 
         return count
 
     def _content_to_model(self, contents):
         """Takes a list of content dicts, optionally with an extra 'origin'
         key, and yields tuples (model.Content, origin)."""
         for content in contents:
             content = content.copy()
             content.pop('origin', None)
             yield Content.from_dict(content)
 
     def content_add(self, content):
         """Add content blobs to the storage
 
         Args:
             content (iterable): iterable of dictionaries representing
                 individual pieces of content to add. Each dictionary has the
                 following keys:
 
                 - data (bytes): the actual content
                 - length (int): content length (default: -1)
                 - one key for each checksum algorithm in
                   :data:`swh.model.hashutil.DEFAULT_ALGORITHMS`, mapped to the
                   corresponding checksum
                 - status (str): one of visible, hidden, absent
                 - reason (str): if status = absent, the reason why
                 - origin (int): if status = absent, the origin we saw the
                   content in
 
         Raises:
             HashCollision in case of collision
 
         Returns:
             Summary dict with the following key and associated values:
 
                 content:add: New contents added
                 content_bytes:add: Sum of the contents' length data
                 skipped_content:add: New skipped contents (no data) added
 
         """
         now = datetime.datetime.now(tz=datetime.timezone.utc)
         content = [attr.evolve(c, ctime=now)
                    for c in self._content_to_model(content)]
         return self._content_add(content, with_data=True)
 
     def content_add_metadata(self, content):
         """Add content metadata to the storage (like `content_add`, but
         without inserting to the objstorage).
 
         Args:
             content (iterable): iterable of dictionaries representing
                 individual pieces of content to add. Each dictionary has the
                 following keys:
 
                 - length (int): content length (default: -1)
                 - one key for each checksum algorithm in
                   :data:`swh.model.hashutil.DEFAULT_ALGORITHMS`, mapped to the
                   corresponding checksum
                 - status (str): one of visible, hidden, absent
                 - reason (str): if status = absent, the reason why
                 - origin (int): if status = absent, the origin we saw the
                   content in
                 - ctime (datetime): time of insertion in the archive
 
         Raises:
             HashCollision in case of collision
 
         Returns:
             Summary dict with the following key and associated values:
 
                 content:add: New contents added
                 skipped_content:add: New skipped contents (no data) added
 
         """
         content = list(self._content_to_model(content))
         return self._content_add(content, with_data=False)
 
     def content_get(self, content):
         """Retrieve in bulk contents and their data.
 
         This function may yield more blobs than provided sha1 identifiers,
         in case they collide.
 
         Args:
             content: iterables of sha1
 
         Yields:
             Dict[str, bytes]: Generates streams of contents as dict with their
                 raw data:
 
                 - sha1 (bytes): content id
                 - data (bytes): content's raw data
 
         Raises:
             ValueError in case of too much contents are required.
             cf. BULK_BLOCK_CONTENT_LEN_MAX
 
         """
         # FIXME: Make this method support slicing the `data`.
         if len(content) > BULK_BLOCK_CONTENT_LEN_MAX:
             raise ValueError(
                 "Sending at most %s contents." % BULK_BLOCK_CONTENT_LEN_MAX)
         for obj_id in content:
             try:
                 data = self.objstorage.get(obj_id)
             except ObjNotFoundError:
                 yield None
                 continue
 
             yield {'sha1': obj_id, 'data': data}
 
     def content_get_range(self, start, end, limit=1000, db=None, cur=None):
         """Retrieve contents within range [start, end] bound by limit.
 
         Note that this function may return more than one blob per hash. The
         limit is enforced with multiplicity (ie. two blobs with the same hash
         will count twice toward the limit).
 
         Args:
             **start** (bytes): Starting identifier range (expected smaller
                            than end)
             **end** (bytes): Ending identifier range (expected larger
                              than start)
             **limit** (int): Limit result (default to 1000)
 
         Returns:
             a dict with keys:
             - contents [dict]: iterable of contents in between the range.
             - next (bytes): There remains content in the range
               starting from this next sha1
 
         """
         if limit is None:
             raise ValueError('Development error: limit should not be None')
         from_index = bisect.bisect_left(self._sorted_sha1s, start)
         sha1s = itertools.islice(self._sorted_sha1s, from_index, None)
         sha1s = ((sha1, content_key)
                  for sha1 in sha1s
                  for content_key in self._content_indexes['sha1'][sha1])
         matched = []
         next_content = None
         for sha1, key in sha1s:
             if sha1 > end:
                 break
             if len(matched) >= limit:
                 next_content = sha1
                 break
             matched.append(self._contents[key].to_dict())
         return {
             'contents': matched,
             'next': next_content,
         }
 
     def content_get_metadata(self, content):
         """Retrieve content metadata in bulk
 
         Args:
             content: iterable of content identifiers (sha1)
 
         Returns:
             an iterable with content metadata corresponding to the given ids
         """
         # FIXME: the return value should be a mapping from search key to found
         # content*s*
         for sha1 in content:
             if sha1 in self._content_indexes['sha1']:
                 objs = self._content_indexes['sha1'][sha1]
                 # FIXME: rather than selecting one of the objects with that
                 # hash, we should return all of them. See:
                 # https://forge.softwareheritage.org/D645?id=1994#inline-3389
                 key = random.sample(objs, 1)[0]
                 d = self._contents[key].to_dict()
                 del d['ctime']
                 yield d
             else:
                 # FIXME: should really be None
                 yield {
                     'sha1': sha1,
                     'sha1_git': None,
                     'sha256': None,
                     'blake2s256': None,
                     'length': None,
                     'status': None,
                 }
 
     def content_find(self, content):
         if not set(content).intersection(DEFAULT_ALGORITHMS):
             raise ValueError('content keys must contain at least one of: '
                              '%s' % ', '.join(sorted(DEFAULT_ALGORITHMS)))
         found = []
         for algo in DEFAULT_ALGORITHMS:
             hash = content.get(algo)
             if hash and hash in self._content_indexes[algo]:
                 found.append(self._content_indexes[algo][hash])
 
         if not found:
             return []
 
         keys = list(set.intersection(*found))
         return [self._contents[key].to_dict() for key in keys]
 
     def content_missing(self, content, key_hash='sha1'):
         """List content missing from storage
 
         Args:
             contents ([dict]): iterable of dictionaries whose keys are
                                either 'length' or an item of
                                :data:`swh.model.hashutil.ALGORITHMS`;
                                mapped to the corresponding checksum
                                (or length).
 
             key_hash (str): name of the column to use as hash id
                             result (default: 'sha1')
 
         Returns:
             iterable ([bytes]): missing content ids (as per the
             key_hash column)
         """
         for cont in content:
             for (algo, hash_) in cont.items():
                 if algo not in DEFAULT_ALGORITHMS:
                     continue
                 if hash_ not in self._content_indexes.get(algo, []):
                     yield cont[key_hash]
                     break
             else:
                 for result in self.content_find(cont):
                     if result['status'] == 'missing':
                         yield cont[key_hash]
 
     def content_missing_per_sha1(self, contents):
         """List content missing from storage based only on sha1.
 
         Args:
             contents: Iterable of sha1 to check for absence.
 
         Returns:
             iterable: missing ids
 
         Raises:
             TODO: an exception when we get a hash collision.
 
         """
         for content in contents:
             if content not in self._content_indexes['sha1']:
                 yield content
 
     def skipped_content_missing(self, contents):
         """List all skipped_content missing from storage
 
         Args:
             contents: Iterable of sha1 to check for skipped content entry
 
         Returns:
             iterable: dict of skipped content entry
         """
 
         for content in contents:
             for (key, algorithm) in self._content_key_algorithm(content):
                 if algorithm == 'blake2s256':
                     continue
                 if key not in self._skipped_content_indexes[algorithm]:
                     # index must contain hashes of algos except blake2s256
                     # else the content is considered skipped
                     yield content
                     break
 
     def content_get_random(self):
         """Finds a random content id.
 
         Returns:
             a sha1_git
         """
         return random.choice(list(self._content_indexes['sha1_git']))
 
     def directory_add(self, directories):
         """Add directories to the storage
 
         Args:
             directories (iterable): iterable of dictionaries representing the
                 individual directories to add. Each dict has the following
                 keys:
 
                 - id (sha1_git): the id of the directory to add
                 - entries (list): list of dicts for each entry in the
                       directory.  Each dict has the following keys:
 
                       - name (bytes)
                       - type (one of 'file', 'dir', 'rev'): type of the
                         directory entry (file, directory, revision)
                       - target (sha1_git): id of the object pointed at by the
                         directory entry
                       - perms (int): entry permissions
         Returns:
             Summary dict of keys with associated count as values:
 
                 directory:add: Number of directories actually added
 
         """
         if self.journal_writer:
             self.journal_writer.write_additions(
                 'directory',
                 (dir_ for dir_ in directories
                  if dir_['id'] not in self._directories))
 
         directories = [Directory.from_dict(d) for d in directories]
 
         count = 0
         for directory in directories:
             if directory.id not in self._directories:
                 count += 1
                 self._directories[directory.id] = directory
                 self._objects[directory.id].append(
                     ('directory', directory.id))
 
         return {'directory:add': count}
 
     def directory_missing(self, directories):
         """List directories missing from storage
 
         Args:
             directories (iterable): an iterable of directory ids
 
         Yields:
             missing directory ids
 
         """
         for id in directories:
             if id not in self._directories:
                 yield id
 
     def _join_dentry_to_content(self, dentry):
         keys = (
             'status',
             'sha1',
             'sha1_git',
             'sha256',
             'length',
         )
         ret = dict.fromkeys(keys)
         ret.update(dentry)
         if ret['type'] == 'file':
             # TODO: Make it able to handle more than one content
             content = self.content_find({'sha1_git': ret['target']})
             if content:
                 content = content[0]
                 for key in keys:
                     ret[key] = content[key]
         return ret
 
     def _directory_ls(self, directory_id, recursive, prefix=b''):
         if directory_id in self._directories:
             for entry in self._directories[directory_id].entries:
                 ret = self._join_dentry_to_content(entry.to_dict())
                 ret['name'] = prefix + ret['name']
                 ret['dir_id'] = directory_id
                 yield ret
                 if recursive and ret['type'] == 'dir':
                     yield from self._directory_ls(
                         ret['target'], True, prefix + ret['name'] + b'/')
 
     def directory_ls(self, directory, recursive=False):
         """Get entries for one directory.
 
         Args:
             - directory: the directory to list entries from.
             - recursive: if flag on, this list recursively from this directory.
 
         Returns:
             List of entries for such directory.
 
         If `recursive=True`, names in the path of a dir/file not at the
         root are concatenated with a slash (`/`).
         """
         yield from self._directory_ls(directory, recursive)
 
     def directory_entry_get_by_path(self, directory, paths):
         """Get the directory entry (either file or dir) from directory with path.
 
         Args:
             - directory: sha1 of the top level directory
             - paths: path to lookup from the top level directory. From left
               (top) to right (bottom).
 
         Returns:
             The corresponding directory entry if found, None otherwise.
 
         """
         return self._directory_entry_get_by_path(directory, paths, b'')
 
     def directory_get_random(self):
         """Finds a random directory id.
 
         Returns:
             a sha1_git
         """
         return random.choice(list(self._directories))
 
     def _directory_entry_get_by_path(self, directory, paths, prefix):
         if not paths:
             return
 
         contents = list(self.directory_ls(directory))
 
         if not contents:
             return
 
         def _get_entry(entries, name):
             for entry in entries:
                 if entry['name'] == name:
                     entry = entry.copy()
                     entry['name'] = prefix + entry['name']
                     return entry
 
         first_item = _get_entry(contents, paths[0])
 
         if len(paths) == 1:
             return first_item
 
         if not first_item or first_item['type'] != 'dir':
             return
 
         return self._directory_entry_get_by_path(
                 first_item['target'], paths[1:], prefix + paths[0] + b'/')
 
     def revision_add(self, revisions):
         """Add revisions to the storage
 
         Args:
             revisions (Iterable[dict]): iterable of dictionaries representing
                 the individual revisions to add. Each dict has the following
                 keys:
 
                 - **id** (:class:`sha1_git`): id of the revision to add
                 - **date** (:class:`dict`): date the revision was written
                 - **committer_date** (:class:`dict`): date the revision got
                   added to the origin
                 - **type** (one of 'git', 'tar'): type of the
                   revision added
                 - **directory** (:class:`sha1_git`): the directory the
                   revision points at
                 - **message** (:class:`bytes`): the message associated with
                   the revision
                 - **author** (:class:`Dict[str, bytes]`): dictionary with
                   keys: name, fullname, email
                 - **committer** (:class:`Dict[str, bytes]`): dictionary with
                   keys: name, fullname, email
                 - **metadata** (:class:`jsonb`): extra information as
                   dictionary
                 - **synthetic** (:class:`bool`): revision's nature (tarball,
                   directory creates synthetic revision`)
                 - **parents** (:class:`list[sha1_git]`): the parents of
                   this revision
 
         date dictionaries have the form defined in :mod:`swh.model`.
 
         Returns:
             Summary dict of keys with associated count as values
 
                 revision_added: New objects actually stored in db
 
         """
         if self.journal_writer:
             self.journal_writer.write_additions(
                 'revision',
                 (rev for rev in revisions
                  if rev['id'] not in self._revisions))
 
         revisions = [Revision.from_dict(rev) for rev in revisions]
 
         count = 0
         for revision in revisions:
             if revision.id not in self._revisions:
                 revision = attr.evolve(
                     revision,
                     committer=self._person_add(revision.committer),
                     author=self._person_add(revision.author))
                 self._revisions[revision.id] = revision
                 self._objects[revision.id].append(
                     ('revision', revision.id))
                 count += 1
 
         return {'revision:add': count}
 
     def revision_missing(self, revisions):
         """List revisions missing from storage
 
         Args:
             revisions (iterable): revision ids
 
         Yields:
             missing revision ids
 
         """
         for id in revisions:
             if id not in self._revisions:
                 yield id
 
     def revision_get(self, revisions):
         for id in revisions:
             if id in self._revisions:
                 yield self._revisions.get(id).to_dict()
             else:
                 yield None
 
     def _get_parent_revs(self, rev_id, seen, limit):
         if limit and len(seen) >= limit:
             return
         if rev_id in seen or rev_id not in self._revisions:
             return
         seen.add(rev_id)
         yield self._revisions[rev_id].to_dict()
         for parent in self._revisions[rev_id].parents:
             yield from self._get_parent_revs(parent, seen, limit)
 
     def revision_log(self, revisions, limit=None):
         """Fetch revision entry from the given root revisions.
 
         Args:
             revisions: array of root revision to lookup
             limit: limitation on the output result. Default to None.
 
         Yields:
             List of revision log from such revisions root.
 
         """
         seen = set()
         for rev_id in revisions:
             yield from self._get_parent_revs(rev_id, seen, limit)
 
     def revision_shortlog(self, revisions, limit=None):
         """Fetch the shortlog for the given revisions
 
         Args:
             revisions: list of root revisions to lookup
             limit: depth limitation for the output
 
         Yields:
             a list of (id, parents) tuples.
 
         """
         yield from ((rev['id'], rev['parents'])
                     for rev in self.revision_log(revisions, limit))
 
     def revision_get_random(self):
         """Finds a random revision id.
 
         Returns:
             a sha1_git
         """
         return random.choice(list(self._revisions))
 
     def release_add(self, releases):
         """Add releases to the storage
 
         Args:
             releases (Iterable[dict]): iterable of dictionaries representing
                 the individual releases to add. Each dict has the following
                 keys:
 
                 - **id** (:class:`sha1_git`): id of the release to add
                 - **revision** (:class:`sha1_git`): id of the revision the
                   release points to
                 - **date** (:class:`dict`): the date the release was made
                 - **name** (:class:`bytes`): the name of the release
                 - **comment** (:class:`bytes`): the comment associated with
                   the release
                 - **author** (:class:`Dict[str, bytes]`): dictionary with
                   keys: name, fullname, email
 
         the date dictionary has the form defined in :mod:`swh.model`.
 
         Returns:
             Summary dict of keys with associated count as values
 
                 release:add: New objects contents actually stored in db
 
         """
         if self.journal_writer:
             self.journal_writer.write_additions(
                 'release',
                 (rel for rel in releases
                  if rel['id'] not in self._releases))
 
         releases = [Release.from_dict(rel) for rel in releases]
 
         count = 0
         for rel in releases:
             if rel.id not in self._releases:
                 if rel.author:
                     self._person_add(rel.author)
                 self._objects[rel.id].append(
                     ('release', rel.id))
                 self._releases[rel.id] = rel
                 count += 1
 
         return {'release:add': count}
 
     def release_missing(self, releases):
         """List releases missing from storage
 
         Args:
             releases: an iterable of release ids
 
         Returns:
             a list of missing release ids
 
         """
         yield from (rel for rel in releases if rel not in self._releases)
 
     def release_get(self, releases):
         """Given a list of sha1, return the releases's information
 
         Args:
             releases: list of sha1s
 
         Yields:
             dicts with the same keys as those given to `release_add`
             (or ``None`` if a release does not exist)
 
         """
         for rel_id in releases:
             if rel_id in self._releases:
                 yield self._releases[rel_id].to_dict()
             else:
                 yield None
 
     def release_get_random(self):
         """Finds a random release id.
 
         Returns:
             a sha1_git
         """
         return random.choice(list(self._releases))
 
     def snapshot_add(self, snapshots):
         """Add a snapshot to the storage
 
         Args:
             snapshot ([dict]): the snapshots to add, containing the
               following keys:
 
               - **id** (:class:`bytes`): id of the snapshot
               - **branches** (:class:`dict`): branches the snapshot contains,
                 mapping the branch name (:class:`bytes`) to the branch target,
                 itself a :class:`dict` (or ``None`` if the branch points to an
                 unknown object)
 
                 - **target_type** (:class:`str`): one of ``content``,
                   ``directory``, ``revision``, ``release``,
                   ``snapshot``, ``alias``
                 - **target** (:class:`bytes`): identifier of the target
                   (currently a ``sha1_git`` for all object kinds, or the name
                   of the target branch for aliases)
 
         Raises:
             ValueError: if the origin's or visit's identifier does not exist.
 
         Returns:
             Summary dict of keys with associated count as values
 
                 snapshot_added: Count of object actually stored in db
 
         """
         count = 0
         snapshots = (Snapshot.from_dict(d) for d in snapshots)
         snapshots = (snap for snap in snapshots
                      if snap.id not in self._snapshots)
         for snapshot in snapshots:
             if self.journal_writer:
                 self.journal_writer.write_addition('snapshot', snapshot)
 
             sorted_branch_names = sorted(snapshot.branches)
             self._snapshots[snapshot.id] = (snapshot, sorted_branch_names)
             self._objects[snapshot.id].append(('snapshot', snapshot.id))
             count += 1
 
         return {'snapshot:add': count}
 
     def snapshot_get(self, snapshot_id):
         """Get the content, possibly partial, of a snapshot with the given id
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         .. warning:: At most 1000 branches contained in the snapshot will be
             returned for performance reasons. In order to browse the whole
             set of branches, the method :meth:`snapshot_get_branches`
             should be used instead.
 
         Args:
             snapshot_id (bytes): identifier of the snapshot
         Returns:
             dict: a dict with three keys:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than 1000
                   branches.
         """
         return self.snapshot_get_branches(snapshot_id)
 
     def snapshot_get_by_origin_visit(self, origin, visit):
         """Get the content, possibly partial, of a snapshot for the given origin visit
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         .. warning:: At most 1000 branches contained in the snapshot will be
             returned for performance reasons. In order to browse the whole
             set of branches, the method :meth:`snapshot_get_branches`
             should be used instead.
 
         Args:
             origin (int): the origin's identifier
             visit (int): the visit's identifier
         Returns:
             dict: None if the snapshot does not exist;
               a dict with three keys otherwise:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than 1000
                   branches.
 
         """
         origin_url = self._get_origin_url(origin)
         if not origin_url:
             return
 
         if origin_url not in self._origins or \
            visit > len(self._origin_visits[origin_url]):
             return None
         snapshot_id = self._origin_visits[origin_url][visit-1].snapshot
         if snapshot_id:
             return self.snapshot_get(snapshot_id)
         else:
             return None
 
     def snapshot_get_latest(self, origin, allowed_statuses=None):
         """Get the content, possibly partial, of the latest snapshot for the
         given origin, optionally only from visits that have one of the given
         allowed_statuses
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         .. warning:: At most 1000 branches contained in the snapshot will be
             returned for performance reasons. In order to browse the whole
             set of branches, the methods :meth:`origin_visit_get_latest`
             and :meth:`snapshot_get_branches` should be used instead.
 
         Args:
             origin (str): the origin's URL
             allowed_statuses (list of str): list of visit statuses considered
                 to find the latest snapshot for the origin. For instance,
                 ``allowed_statuses=['full']`` will only consider visits that
                 have successfully run to completion.
         Returns:
             dict: a dict with three keys:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than 1000
                   branches.
         """
         origin_url = self._get_origin_url(origin)
         if not origin_url:
             return
 
         visit = self.origin_visit_get_latest(
             origin_url,
             allowed_statuses=allowed_statuses,
             require_snapshot=True)
         if visit and visit['snapshot']:
             snapshot = self.snapshot_get(visit['snapshot'])
             if not snapshot:
                 raise ValueError(
                     'last origin visit references an unknown snapshot')
             return snapshot
 
     def snapshot_count_branches(self, snapshot_id, db=None, cur=None):
         """Count the number of branches in the snapshot with the given id
 
         Args:
             snapshot_id (bytes): identifier of the snapshot
 
         Returns:
             dict: A dict whose keys are the target types of branches and
             values their corresponding amount
         """
         (snapshot, _) = self._snapshots[snapshot_id]
         return collections.Counter(branch.target_type.value if branch else None
                                    for branch in snapshot.branches.values())
 
     def snapshot_get_branches(self, snapshot_id, branches_from=b'',
                               branches_count=1000, target_types=None):
         """Get the content, possibly partial, of a snapshot with the given id
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         Args:
             snapshot_id (bytes): identifier of the snapshot
             branches_from (bytes): optional parameter used to skip branches
                 whose name is lesser than it before returning them
             branches_count (int): optional parameter used to restrain
                 the amount of returned branches
             target_types (list): optional parameter used to filter the
                 target types of branch to return (possible values that can be
                 contained in that list are `'content', 'directory',
                 'revision', 'release', 'snapshot', 'alias'`)
         Returns:
             dict: None if the snapshot does not exist;
               a dict with three keys otherwise:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than
                   `branches_count` branches after `branches_from` included.
         """
         res = self._snapshots.get(snapshot_id)
         if res is None:
             return None
         (snapshot, sorted_branch_names) = res
         from_index = bisect.bisect_left(
                 sorted_branch_names, branches_from)
         if target_types:
             next_branch = None
             branches = {}
             for branch_name in sorted_branch_names[from_index:]:
                 branch = snapshot.branches[branch_name]
                 if branch and branch.target_type.value in target_types:
                     if len(branches) < branches_count:
                         branches[branch_name] = branch
                     else:
                         next_branch = branch_name
                         break
         else:
             # As there is no 'target_types', we can do that much faster
             to_index = from_index + branches_count
             returned_branch_names = sorted_branch_names[from_index:to_index]
             branches = {branch_name: snapshot.branches[branch_name]
                         for branch_name in returned_branch_names}
             if to_index >= len(sorted_branch_names):
                 next_branch = None
             else:
                 next_branch = sorted_branch_names[to_index]
 
         branches = {name: branch.to_dict() if branch else None
                     for (name, branch) in branches.items()}
 
         return {
                 'id': snapshot_id,
                 'branches': branches,
                 'next_branch': next_branch,
                 }
 
     def snapshot_get_random(self):
         """Finds a random snapshot id.
 
         Returns:
             a sha1_git
         """
         return random.choice(list(self._snapshots))
 
     def object_find_by_sha1_git(self, ids, db=None, cur=None):
         """Return the objects found with the given ids.
 
         Args:
             ids: a generator of sha1_gits
 
         Returns:
             dict: a mapping from id to the list of objects found. Each object
             found is itself a dict with keys:
 
             - sha1_git: the input id
             - type: the type of object found
             - id: the id of the object found
             - object_id: the numeric id of the object found.
 
         """
         ret = {}
         for id_ in ids:
             objs = self._objects.get(id_, [])
             ret[id_] = [{
                     'sha1_git': id_,
                     'type': obj[0],
                     'id': obj[1],
                     'object_id': id_,
                     } for obj in objs]
         return ret
 
     def _convert_origin(self, t):
         if t is None:
             return None
 
         return t.to_dict()
 
     def origin_get(self, origins):
         """Return origins, either all identified by their ids or all
         identified by urls.
 
         Args:
             origin: a list of dictionaries representing the individual
                 origins to find.
                 These dicts have either the key url (and optionally type):
 
                 - url (bytes): the url the origin points to
 
                 or the id:
 
                 - id (int): the origin's identifier
 
         Returns:
             dict: the origin dictionary with the keys:
 
             - id: origin's id
             - url: origin's url
 
         Raises:
             ValueError: if the keys does not match (url and type) nor id.
 
         """
         if isinstance(origins, dict):
             # Old API
             return_single = True
             origins = [origins]
         else:
             return_single = False
 
         # Sanity check to be error-compatible with the pgsql backend
         if any('id' in origin for origin in origins) \
                 and not all('id' in origin for origin in origins):
             raise ValueError(
                 'Either all origins or none at all should have an "id".')
         if any('url' in origin for origin in origins) \
                 and not all('url' in origin for origin in origins):
             raise ValueError(
                 'Either all origins or none at all should have '
                 'an "url" key.')
 
         results = []
         for origin in origins:
             result = None
             if 'url' in origin:
                 if origin['url'] in self._origins:
                     result = self._origins[origin['url']]
             else:
                 raise ValueError(
                     'Origin must have an url.')
             results.append(self._convert_origin(result))
 
         if return_single:
             assert len(results) == 1
             return results[0]
         else:
             return results
 
     def origin_get_by_sha1(self, sha1s):
         """Return origins, identified by the sha1 of their URLs.
 
         Args:
             sha1s (list[bytes]): a list of sha1s
 
         Yields:
             dicts containing origin information as returned
             by :meth:`swh.storage.in_memory.Storage.origin_get`, or None if an
             origin matching the sha1 is not found.
         """
         return [
             self._convert_origin(self._origins_by_sha1.get(sha1))
             for sha1 in sha1s
         ]
 
     def origin_get_range(self, origin_from=1, origin_count=100):
         """Retrieve ``origin_count`` origins whose ids are greater
         or equal than ``origin_from``.
 
         Origins are sorted by id before retrieving them.
 
         Args:
             origin_from (int): the minimum id of origins to retrieve
             origin_count (int): the maximum number of origins to retrieve
 
         Yields:
             dicts containing origin information as returned
             by :meth:`swh.storage.in_memory.Storage.origin_get`, plus
             an 'id' key.
         """
         origin_from = max(origin_from, 1)
         if origin_from <= len(self._origins_by_id):
             max_idx = origin_from + origin_count - 1
             if max_idx > len(self._origins_by_id):
                 max_idx = len(self._origins_by_id)
             for idx in range(origin_from-1, max_idx):
                 origin = self._convert_origin(
                     self._origins[self._origins_by_id[idx]])
                 yield {'id': idx+1, **origin}
 
+    def origin_list(self, page_token: Optional[str] = None, limit: int = 100
+                    ) -> dict:
+        """Returns the list of origins
+
+        Args:
+            page_token: opaque token used for pagination.
+            limit: the maximum number of results to return
+
+        Returns:
+            dict: dict with the following keys:
+              - **next_page_token** (str, optional): opaque token to be used as
+                `page_token` for retrieving the next page. if absent, there is
+                no more pages to gather.
+              - **origins** (List[dict]): list of origins, as returned by
+                `origin_get`.
+        """
+        origin_urls = sorted(self._origins)
+        if page_token:
+            from_ = bisect.bisect_left(origin_urls, page_token)
+        else:
+            from_ = 0
+
+        result = {
+            'origins': [{'url': origin_url}
+                        for origin_url in origin_urls[from_:from_+limit]]
+        }
+
+        if from_+limit < len(origin_urls):
+            result['next_page_token'] = origin_urls[from_+limit]
+
+        return result
+
     def origin_search(self, url_pattern, offset=0, limit=50,
                       regexp=False, with_visit=False, db=None, cur=None):
         """Search for origins whose urls contain a provided string pattern
         or match a provided regular expression.
         The search is performed in a case insensitive way.
 
         Args:
             url_pattern (str): the string pattern to search for in origin urls
             offset (int): number of found origins to skip before returning
                 results
             limit (int): the maximum number of found origins to return
             regexp (bool): if True, consider the provided pattern as a regular
                 expression and return origins whose urls match it
             with_visit (bool): if True, filter out origins with no visit
 
         Returns:
             An iterable of dict containing origin information as returned
             by :meth:`swh.storage.storage.Storage.origin_get`.
         """
         origins = map(self._convert_origin, self._origins.values())
         if regexp:
             pat = re.compile(url_pattern)
             origins = [orig for orig in origins if pat.search(orig['url'])]
         else:
             origins = [orig for orig in origins if url_pattern in orig['url']]
         if with_visit:
             origins = [
                 orig for orig in origins
                 if len(self._origin_visits[orig['url']]) > 0 and
                 set(ov.snapshot
                     for ov in self._origin_visits[orig['url']]
                     if ov.snapshot) &
                 set(self._snapshots)]
 
         return origins[offset:offset+limit]
 
     def origin_count(self, url_pattern, regexp=False, with_visit=False,
                      db=None, cur=None):
         """Count origins whose urls contain a provided string pattern
         or match a provided regular expression.
         The pattern search in origin urls is performed in a case insensitive
         way.
 
         Args:
             url_pattern (str): the string pattern to search for in origin urls
             regexp (bool): if True, consider the provided pattern as a regular
                 expression and return origins whose urls match it
             with_visit (bool): if True, filter out origins with no visit
 
         Returns:
             int: The number of origins matching the search criterion.
         """
         return len(self.origin_search(url_pattern, regexp=regexp,
                                       with_visit=with_visit,
                                       limit=len(self._origins)))
 
     def origin_add(self, origins):
         """Add origins to the storage
 
         Args:
             origins: list of dictionaries representing the individual origins,
                 with the following keys:
 
                 - url (bytes): the url the origin points to
 
         Returns:
             list: given origins as dict updated with their id
 
         """
         origins = copy.deepcopy(origins)
         for origin in origins:
             self.origin_add_one(origin)
         return origins
 
     def origin_add_one(self, origin):
         """Add origin to the storage
 
         Args:
             origin: dictionary representing the individual origin to add. This
                 dict has the following keys:
 
                 - url (bytes): the url the origin points to
 
         Returns:
             the id of the added origin, or of the identical one that already
             exists.
 
         """
         origin = Origin.from_dict(origin)
         if origin.url not in self._origins:
             if self.journal_writer:
                 self.journal_writer.write_addition('origin', origin)
 
             # generate an origin_id because it is needed by origin_get_range.
             # TODO: remove this when we remove origin_get_range
             origin_id = len(self._origins) + 1
             self._origins_by_id.append(origin.url)
             assert len(self._origins_by_id) == origin_id
 
             self._origins[origin.url] = origin
             self._origins_by_sha1[origin_url_to_sha1(origin.url)] = origin
             self._origin_visits[origin.url] = []
             self._objects[origin.url].append(('origin', origin.url))
 
         return origin.url
 
     def origin_visit_add(self, origin, date, type):
         """Add an origin_visit for the origin at date with status 'ongoing'.
 
         Args:
             origin (str): visited origin's identifier or URL
             date (Union[str,datetime]): timestamp of such visit
             type (str): the type of loader used for the visit (hg, git, ...)
 
         Returns:
             dict: dictionary with keys origin and visit where:
 
             - origin: origin's identifier
             - visit: the visit's identifier for the new visit occurrence
 
         """
         origin_url = origin
         if origin_url is None:
             raise ValueError('Unknown origin.')
 
         if isinstance(date, str):
             # FIXME: Converge on iso8601 at some point
             date = dateutil.parser.parse(date)
         elif not isinstance(date, datetime.datetime):
             raise TypeError('date must be a datetime or a string.')
 
         visit_ret = None
         if origin_url in self._origins:
             origin = self._origins[origin_url]
             # visit ids are in the range [1, +inf[
             visit_id = len(self._origin_visits[origin_url]) + 1
             status = 'ongoing'
             visit = OriginVisit(
                 origin=origin.url,
                 date=date,
                 type=type,
                 status=status,
                 snapshot=None,
                 metadata=None,
                 visit=visit_id,
             )
             self._origin_visits[origin_url].append(visit)
             visit_ret = {
                 'origin': origin.url,
                 'visit': visit_id,
             }
 
             self._objects[(origin_url, visit_id)].append(
                 ('origin_visit', None))
 
             if self.journal_writer:
                 self.journal_writer.write_addition('origin_visit', visit)
 
         return visit_ret
 
     def origin_visit_update(self, origin, visit_id, status=None,
                             metadata=None, snapshot=None):
         """Update an origin_visit's status.
 
         Args:
             origin (str): visited origin's URL
             visit_id (int): visit's identifier
             status: visit's new status
             metadata: data associated to the visit
             snapshot (sha1_git): identifier of the snapshot to add to
                 the visit
 
         Returns:
             None
 
         """
         if not isinstance(origin, str):
             raise TypeError('origin must be a string, not %r' % (origin,))
         origin_url = self._get_origin_url(origin)
         if origin_url is None:
             raise ValueError('Unknown origin.')
 
         try:
             visit = self._origin_visits[origin_url][visit_id-1]
         except IndexError:
             raise ValueError('Unknown visit_id for this origin') \
                 from None
 
         updates = {}
         if status:
             updates['status'] = status
         if metadata:
             updates['metadata'] = metadata
         if snapshot:
             updates['snapshot'] = snapshot
 
         visit = attr.evolve(visit, **updates)
 
         if self.journal_writer:
             self.journal_writer.write_update('origin_visit', visit)
 
         self._origin_visits[origin_url][visit_id-1] = visit
 
     def origin_visit_upsert(self, visits):
         """Add a origin_visits with a specific id and with all its data.
         If there is already an origin_visit with the same
         `(origin_url, visit_id)`, updates it instead of inserting a new one.
 
         Args:
             visits: iterable of dicts with keys:
 
                 origin: origin url
                 visit: origin visit id
                 type: type of loader used for the visit
                 date: timestamp of such visit
                 status: Visit's new status
                 metadata: Data associated to the visit
                 snapshot (sha1_git): identifier of the snapshot to add to
                     the visit
         """
         for visit in visits:
             if not isinstance(visit['origin'], str):
                 raise TypeError("visit['origin'] must be a string, not %r"
                                 % (visit['origin'],))
         visits = [OriginVisit.from_dict(d) for d in visits]
 
         if self.journal_writer:
             for visit in visits:
                 self.journal_writer.write_addition('origin_visit', visit)
 
         for visit in visits:
             visit_id = visit.visit
             origin_url = visit.origin
 
             visit = attr.evolve(visit, origin=origin_url)
 
             self._objects[(origin_url, visit_id)].append(
                 ('origin_visit', None))
 
             while len(self._origin_visits[origin_url]) <= visit_id:
                 self._origin_visits[origin_url].append(None)
 
             self._origin_visits[origin_url][visit_id-1] = visit
 
     def _convert_visit(self, visit):
         if visit is None:
             return
 
         visit = visit.to_dict()
 
         return visit
 
     def origin_visit_get(self, origin, last_visit=None, limit=None):
         """Retrieve all the origin's visit's information.
 
         Args:
             origin (int): the origin's identifier
             last_visit (int): visit's id from which listing the next ones,
                 default to None
             limit (int): maximum number of results to return,
                 default to None
 
         Yields:
             List of visits.
 
         """
         origin_url = self._get_origin_url(origin)
         if origin_url in self._origin_visits:
             visits = self._origin_visits[origin_url]
             if last_visit is not None:
                 visits = visits[last_visit:]
             if limit is not None:
                 visits = visits[:limit]
             for visit in visits:
                 if not visit:
                     continue
                 visit_id = visit.visit
 
                 yield self._convert_visit(
                     self._origin_visits[origin_url][visit_id-1])
 
     def origin_visit_find_by_date(self, origin, visit_date):
         """Retrieves the origin visit whose date is closest to the provided
         timestamp.
         In case of a tie, the visit with largest id is selected.
 
         Args:
             origin (str): The occurrence's origin (URL).
             target (datetime): target timestamp
 
         Returns:
             A visit.
 
         """
         origin_url = self._get_origin_url(origin)
         if origin_url in self._origin_visits:
             visits = self._origin_visits[origin_url]
             visit = min(
                 visits,
                 key=lambda v: (abs(v.date - visit_date), -v.visit))
             return self._convert_visit(visit)
 
     def origin_visit_get_by(self, origin, visit):
         """Retrieve origin visit's information.
 
         Args:
             origin (int): the origin's identifier
 
         Returns:
             The information on that particular (origin, visit) or None if
             it does not exist
 
         """
         origin_url = self._get_origin_url(origin)
         if origin_url in self._origin_visits and \
            visit <= len(self._origin_visits[origin_url]):
             return self._convert_visit(
                 self._origin_visits[origin_url][visit-1])
 
     def origin_visit_get_latest(
             self, origin, allowed_statuses=None, require_snapshot=False):
         """Get the latest origin visit for the given origin, optionally
         looking only for those with one of the given allowed_statuses
         or for those with a known snapshot.
 
         Args:
             origin (str): the origin's URL
             allowed_statuses (list of str): list of visit statuses considered
                 to find the latest visit. For instance,
                 ``allowed_statuses=['full']`` will only consider visits that
                 have successfully run to completion.
             require_snapshot (bool): If True, only a visit with a snapshot
                 will be returned.
         Returns:
             dict: a dict with the following keys:
 
                 origin: the URL of the origin
                 visit: origin visit id
                 type: type of loader used for the visit
                 date: timestamp of such visit
                 status: Visit's new status
                 metadata: Data associated to the visit
                 snapshot (Optional[sha1_git]): identifier of the snapshot
                     associated to the visit
         """
         origin = self._origins.get(origin)
         if not origin:
             return
         visits = self._origin_visits[origin.url]
         if allowed_statuses is not None:
             visits = [visit for visit in visits
                       if visit.status in allowed_statuses]
         if require_snapshot:
             visits = [visit for visit in visits
                       if visit.snapshot]
 
         visit = max(
             visits, key=lambda v: (v.date, v.visit), default=None)
         return self._convert_visit(visit)
 
     def _select_random_origin_visit_by_type(self, type: str) -> str:
         """Select randomly an origin visit """
         while True:
             url = random.choice(list(self._origin_visits.keys()))
             random_origin_visits = self._origin_visits[url]
             if random_origin_visits[0].type == type:
                 return url
 
     def origin_visit_get_random(self, type: str) -> Mapping[str, Any]:
         """Randomly select one successful origin visit with <type>
         made in the last 3 months.
 
         Returns:
             dict representing an origin visit, in the same format as
             `origin_visit_get`.
 
         """
         random_visit: Dict[str, Any] = {}
         if not self._origin_visits:  # empty dataset
             return random_visit
         url = self._select_random_origin_visit_by_type(type)
         random_origin_visits = copy.deepcopy(self._origin_visits[url])
         random_origin_visits.reverse()
         back_in_the_day = now() - timedelta(weeks=12)  # 3 months back
         # This should be enough for tests
         for visit in random_origin_visits:
             if visit.date > back_in_the_day and visit.status == 'full':
                 random_visit = visit.to_dict()
                 break
         return random_visit
 
     def stat_counters(self):
         """compute statistics about the number of tuples in various tables
 
         Returns:
             dict: a dictionary mapping textual labels (e.g., content) to
             integer values (e.g., the number of tuples in table content)
 
         """
         keys = (
             'content',
             'directory',
             'origin',
             'origin_visit',
             'person',
             'release',
             'revision',
             'skipped_content',
             'snapshot'
             )
         stats = {key: 0 for key in keys}
         stats.update(collections.Counter(
             obj_type
             for (obj_type, obj_id)
             in itertools.chain(*self._objects.values())))
         return stats
 
     def refresh_stat_counters(self):
         """Recomputes the statistics for `stat_counters`."""
         pass
 
     def origin_metadata_add(self, origin_url, ts, provider, tool, metadata,
                             db=None, cur=None):
         """ Add an origin_metadata for the origin at ts with provenance and
         metadata.
 
         Args:
             origin_url (str): the origin url for which the metadata is added
             ts (datetime): timestamp of the found metadata
             provider: id of the provider of metadata (ex:'hal')
             tool: id of the tool used to extract metadata
             metadata (jsonb): the metadata retrieved at the time and location
         """
         if not isinstance(origin_url, str):
             raise TypeError('origin_id must be str, not %r' % (origin_url,))
 
         if isinstance(ts, str):
             ts = dateutil.parser.parse(ts)
 
         origin_metadata = {
                 'origin_url': origin_url,
                 'discovery_date': ts,
                 'tool_id': tool,
                 'metadata': metadata,
                 'provider_id': provider,
                 }
         self._origin_metadata[origin_url].append(origin_metadata)
         return None
 
     def origin_metadata_get_by(self, origin_url, provider_type=None, db=None,
                                cur=None):
         """Retrieve list of all origin_metadata entries for the origin_url
 
         Args:
             origin_url (str): the origin's url
             provider_type (str): (optional) type of provider
 
         Returns:
             list of dicts: the origin_metadata dictionary with the keys:
 
             - origin_url (int): origin's URL
             - discovery_date (datetime): timestamp of discovery
             - tool_id (int): metadata's extracting tool
             - metadata (jsonb)
             - provider_id (int): metadata's provider
             - provider_name (str)
             - provider_type (str)
             - provider_url (str)
 
         """
         if not isinstance(origin_url, str):
             raise TypeError('origin_url must be str, not %r' % (origin_url,))
         metadata = []
         for item in self._origin_metadata[origin_url]:
             item = copy.deepcopy(item)
             provider = self.metadata_provider_get(item['provider_id'])
             for attr_name in ('name', 'type', 'url'):
                 item['provider_' + attr_name] = \
                     provider['provider_' + attr_name]
             metadata.append(item)
         return metadata
 
     def tool_add(self, tools):
         """Add new tools to the storage.
 
         Args:
             tools (iterable of :class:`dict`): Tool information to add to
               storage. Each tool is a :class:`dict` with the following keys:
 
               - name (:class:`str`): name of the tool
               - version (:class:`str`): version of the tool
               - configuration (:class:`dict`): configuration of the tool,
                 must be json-encodable
 
         Returns:
             :class:`dict`: All the tools inserted in storage
             (including the internal ``id``). The order of the list is not
             guaranteed to match the order of the initial list.
 
         """
         inserted = []
         for tool in tools:
             key = self._tool_key(tool)
             assert 'id' not in tool
             record = copy.deepcopy(tool)
             record['id'] = key  # TODO: remove this
             if key not in self._tools:
                 self._tools[key] = record
             inserted.append(copy.deepcopy(self._tools[key]))
 
         return inserted
 
     def tool_get(self, tool):
         """Retrieve tool information.
 
         Args:
             tool (dict): Tool information we want to retrieve from storage.
               The dicts have the same keys as those used in :func:`tool_add`.
 
         Returns:
             dict: The full tool information if it exists (``id`` included),
             None otherwise.
 
         """
         return self._tools.get(self._tool_key(tool))
 
     def metadata_provider_add(self, provider_name, provider_type, provider_url,
                               metadata):
         """Add a metadata provider.
 
         Args:
             provider_name (str): Its name
             provider_type (str): Its type
             provider_url (str): Its URL
             metadata: JSON-encodable object
 
         Returns:
             an identifier of the provider
         """
         provider = {
                 'provider_name': provider_name,
                 'provider_type': provider_type,
                 'provider_url': provider_url,
                 'metadata': metadata,
                 }
         key = self._metadata_provider_key(provider)
         provider['id'] = key
         self._metadata_providers[key] = provider
         return key
 
     def metadata_provider_get(self, provider_id, db=None, cur=None):
         """Get a metadata provider
 
         Args:
             provider_id: Its identifier, as given by `metadata_provider_add`.
 
         Returns:
             dict: same as `metadata_provider_add`;
                   or None if it does not exist.
         """
         return self._metadata_providers.get(provider_id)
 
     def metadata_provider_get_by(self, provider, db=None, cur=None):
         """Get a metadata provider
 
         Args:
             provider_name: Its name
             provider_url: Its URL
 
         Returns:
             dict: same as `metadata_provider_add`;
                   or None if it does not exist.
         """
         key = self._metadata_provider_key(provider)
         return self._metadata_providers.get(key)
 
     def _get_origin_url(self, origin):
         if isinstance(origin, str):
             return origin
         else:
             raise TypeError('origin must be a string.')
 
     def _person_add(self, person):
         """Add a person in storage.
 
         Note: Private method, do not use outside of this class.
 
         Args:
             person: dictionary with keys fullname, name and email.
 
         """
         key = ('person', person.fullname)
         if key not in self._objects:
             person_id = len(self._persons) + 1
             self._persons.append(person)
             self._objects[key].append(('person', person_id))
         else:
             person_id = self._objects[key][0][1]
             person = self._persons[person_id-1]
         return person
 
     @staticmethod
     def _content_key(content):
         """A stable key for a content"""
         return tuple(getattr(content, key)
                      for key in sorted(DEFAULT_ALGORITHMS))
 
     @staticmethod
     def _content_key_algorithm(content):
         """ A stable key and the algorithm for a content"""
         if isinstance(content, Content):
             content = content.to_dict()
         return tuple((content.get(key), key)
                      for key in sorted(DEFAULT_ALGORITHMS))
 
     @staticmethod
     def _tool_key(tool):
         return '%r %r %r' % (tool['name'], tool['version'],
                              tuple(sorted(tool['configuration'].items())))
 
     @staticmethod
     def _metadata_provider_key(provider):
         return '%r %r' % (provider['provider_name'], provider['provider_url'])
diff --git a/swh/storage/storage.py b/swh/storage/storage.py
index e3fe477f..350c3313 100644
--- a/swh/storage/storage.py
+++ b/swh/storage/storage.py
@@ -1,2047 +1,2086 @@
 # Copyright (C) 2015-2019  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import copy
 import datetime
 import itertools
 import json
 
 from collections import defaultdict
 from concurrent.futures import ThreadPoolExecutor
 from contextlib import contextmanager
-from typing import Any, Dict, Mapping
+from typing import Any, Dict, Mapping, Optional
 
 import dateutil.parser
 import psycopg2
 import psycopg2.pool
 
 from swh.core.api import remote_api_endpoint
 from swh.model.hashutil import ALGORITHMS, hash_to_bytes
 from swh.objstorage import get_objstorage
 from swh.objstorage.exc import ObjNotFoundError
 try:
     from swh.journal.writer import get_journal_writer
 except ImportError:
     get_journal_writer = None  # type: ignore
     # mypy limitation, see https://github.com/python/mypy/issues/1153
 
 from . import converters
 from .common import db_transaction_generator, db_transaction
 from .db import Db
 from .exc import StorageDBError
 from .algos import diff
 from .metrics import timed, send_metric, process_metrics
 
 
 # Max block size of contents to return
 BULK_BLOCK_CONTENT_LEN_MAX = 10000
 
 EMPTY_SNAPSHOT_ID = hash_to_bytes('1a8893e6a86f444e8be8e7bda6cb34fb1735a00e')
 """Identifier for the empty snapshot"""
 
 
 class Storage():
     """SWH storage proxy, encompassing DB and object storage
 
     """
 
     def __init__(self, db, objstorage, min_pool_conns=1, max_pool_conns=10,
                  journal_writer=None):
         """
         Args:
             db_conn: either a libpq connection string, or a psycopg2 connection
             obj_root: path to the root of the object storage
 
         """
         try:
             if isinstance(db, psycopg2.extensions.connection):
                 self._pool = None
                 self._db = Db(db)
             else:
                 self._pool = psycopg2.pool.ThreadedConnectionPool(
                     min_pool_conns, max_pool_conns, db
                 )
                 self._db = None
         except psycopg2.OperationalError as e:
             raise StorageDBError(e)
 
         self.objstorage = get_objstorage(**objstorage)
         if journal_writer:
             if get_journal_writer is None:
                 raise EnvironmentError(
                     'You need the swh.journal package to use the '
                     'journal_writer feature')
             self.journal_writer = get_journal_writer(**journal_writer)
         else:
             self.journal_writer = None
 
     def get_db(self):
         if self._db:
             return self._db
         else:
             return Db.from_pool(self._pool)
 
     def put_db(self, db):
         if db is not self._db:
             db.put_conn()
 
     @contextmanager
     def db(self):
         db = None
         try:
             db = self.get_db()
             yield db
         finally:
             if db:
                 self.put_db(db)
 
     @remote_api_endpoint('check_config')
     @timed
     @db_transaction()
     def check_config(self, *, check_write, db=None, cur=None):
         """Check that the storage is configured and ready to go."""
 
         if not self.objstorage.check_config(check_write=check_write):
             return False
 
         # Check permissions on one of the tables
         if check_write:
             check = 'INSERT'
         else:
             check = 'SELECT'
 
         cur.execute(
             "select has_table_privilege(current_user, 'content', %s)",
             (check,)
         )
         return cur.fetchone()[0]
 
     def _content_unique_key(self, hash, db):
         """Given a hash (tuple or dict), return a unique key from the
            aggregation of keys.
 
         """
         keys = db.content_hash_keys
         if isinstance(hash, tuple):
             return hash
         return tuple([hash[k] for k in keys])
 
     @staticmethod
     def _normalize_content(d):
         d = d.copy()
 
         if 'status' not in d:
             d['status'] = 'visible'
 
         if 'length' not in d:
             d['length'] = -1
 
         return d
 
     @staticmethod
     def _validate_content(d):
         """Sanity checks on status / reason / length, that postgresql
         doesn't enforce."""
         if d['status'] not in ('visible', 'absent', 'hidden'):
             raise ValueError('Invalid content status: {}'.format(d['status']))
 
         if d['status'] != 'absent' and d.get('reason') is not None:
             raise ValueError(
                 'Must not provide a reason if content is not absent.')
 
         if d['length'] < -1:
             raise ValueError('Content length must be positive or -1.')
 
     def _filter_new_content(self, content, db=None, cur=None):
         """Sort contents into buckets 'with data' and 'without data',
         and filter out those already in the database."""
         content_by_status = defaultdict(list)
         for d in content:
             content_by_status[d['status']].append(d)
 
         content_with_data = content_by_status['visible'] \
             + content_by_status['hidden']
         content_without_data = content_by_status['absent']
 
         missing_content = set(self.content_missing(content_with_data,
                                                    db=db, cur=cur))
         missing_skipped = set(self._content_unique_key(hashes, db)
                               for hashes in self.skipped_content_missing(
                                   content_without_data, db=db, cur=cur))
 
         content_with_data = [
             cont for cont in content_with_data
             if cont['sha1'] in missing_content]
         content_without_data = [
             cont for cont in content_without_data
             if self._content_unique_key(cont, db) in missing_skipped]
 
         summary = {
             'content:add': len(missing_content),
             'skipped_content:add': len(missing_skipped),
         }
 
         return (content_with_data, content_without_data, summary)
 
     def _content_add_metadata(self, db, cur,
                               content_with_data, content_without_data):
         """Add content to the postgresql database but not the object storage.
         """
         if content_with_data:
             # create temporary table for metadata injection
             db.mktemp('content', cur)
 
             db.copy_to(content_with_data, 'tmp_content',
                        db.content_add_keys, cur)
 
             # move metadata in place
             try:
                 db.content_add_from_temp(cur)
             except psycopg2.IntegrityError as e:
                 from . import HashCollision
                 if e.diag.sqlstate == '23505' and \
                         e.diag.table_name == 'content':
                     constraint_to_hash_name = {
                         'content_pkey': 'sha1',
                         'content_sha1_git_idx': 'sha1_git',
                         'content_sha256_idx': 'sha256',
                         }
                     colliding_hash_name = constraint_to_hash_name \
                         .get(e.diag.constraint_name)
                     raise HashCollision(colliding_hash_name) from None
                 else:
                     raise
 
         if content_without_data:
             content_without_data = \
                 [cont.copy() for cont in content_without_data]
             origin_ids = db.origin_id_get_by_url(
                 [cont.get('origin') for cont in content_without_data],
                 cur=cur)
             for (cont, origin_id) in zip(content_without_data, origin_ids):
                 if 'origin' in cont:
                     cont['origin'] = origin_id
             db.mktemp('skipped_content', cur)
             db.copy_to(content_without_data, 'tmp_skipped_content',
                        db.skipped_content_keys, cur)
 
             # move metadata in place
             db.skipped_content_add_from_temp(cur)
 
     @remote_api_endpoint('content/add')
     @timed
     @process_metrics
     @db_transaction()
     def content_add(self, content, db=None, cur=None):
         """Add content blobs to the storage
 
         Note: in case of DB errors, objects might have already been added to
         the object storage and will not be removed. Since addition to the
         object storage is idempotent, that should not be a problem.
 
         Args:
             contents (iterable): iterable of dictionaries representing
                 individual pieces of content to add. Each dictionary has the
                 following keys:
 
                 - data (bytes): the actual content
                 - length (int): content length (default: -1)
                 - one key for each checksum algorithm in
                   :data:`swh.model.hashutil.ALGORITHMS`, mapped to the
                   corresponding checksum
                 - status (str): one of visible, hidden, absent
                 - reason (str): if status = absent, the reason why
                 - origin (int): if status = absent, the origin we saw the
                   content in
 
         Raises:
 
             In case of errors, nothing is stored in the db (in the
             objstorage, it could though). The following exceptions can
             occur:
 
             - HashCollision in case of collision
             - Any other exceptions raise by the db
 
         Returns:
             Summary dict with the following key and associated values:
 
                 content:add: New contents added
                 content:add:bytes: Sum of the contents' length data
                 skipped_content:add: New skipped contents (no data) added
         """
         content = [dict(c.items()) for c in content]  # semi-shallow copy
         now = datetime.datetime.now(tz=datetime.timezone.utc)
         for item in content:
             item['ctime'] = now
 
         content = [self._normalize_content(c) for c in content]
         for c in content:
             self._validate_content(c)
 
         (content_with_data, content_without_data, summary) = \
             self._filter_new_content(content, db, cur)
 
         if self.journal_writer:
             for item in content_with_data:
                 if 'data' in item:
                     item = item.copy()
                     del item['data']
                 self.journal_writer.write_addition('content', item)
             for item in content_without_data:
                 self.journal_writer.write_addition('content', item)
 
         def add_to_objstorage():
             """Add to objstorage the new missing_content
 
             Returns:
                 Sum of all the content's data length pushed to the
                 objstorage. Content present twice is only sent once.
 
             """
             content_bytes_added = 0
             data = {}
             for cont in content_with_data:
                 if cont['sha1'] not in data:
                     data[cont['sha1']] = cont['data']
                     content_bytes_added += max(0, cont['length'])
 
             # FIXME: Since we do the filtering anyway now, we might as
             # well make the objstorage's add_batch call return what we
             # want here (real bytes added)... that'd simplify this...
             self.objstorage.add_batch(data)
             return content_bytes_added
 
         with ThreadPoolExecutor(max_workers=1) as executor:
             added_to_objstorage = executor.submit(add_to_objstorage)
 
             self._content_add_metadata(
                 db, cur, content_with_data, content_without_data)
 
             # Wait for objstorage addition before returning from the
             # transaction, bubbling up any exception
             content_bytes_added = added_to_objstorage.result()
 
         summary['content:add:bytes'] = content_bytes_added
         return summary
 
     @remote_api_endpoint('content/update')
     @timed
     @db_transaction()
     def content_update(self, content, keys=[], db=None, cur=None):
         """Update content blobs to the storage. Does nothing for unknown
         contents or skipped ones.
 
         Args:
             content (iterable): iterable of dictionaries representing
                 individual pieces of content to update. Each dictionary has the
                 following keys:
 
                 - data (bytes): the actual content
                 - length (int): content length (default: -1)
                 - one key for each checksum algorithm in
                   :data:`swh.model.hashutil.ALGORITHMS`, mapped to the
                   corresponding checksum
                 - status (str): one of visible, hidden, absent
 
             keys (list): List of keys (str) whose values needs an update, e.g.,
                 new hash column
 
         """
         # TODO: Add a check on input keys. How to properly implement
         # this? We don't know yet the new columns.
 
         if self.journal_writer:
             raise NotImplementedError(
                 'content_update is not yet support with a journal_writer.')
 
         db.mktemp('content', cur)
         select_keys = list(set(db.content_get_metadata_keys).union(set(keys)))
         db.copy_to(content, 'tmp_content', select_keys, cur)
         db.content_update_from_temp(keys_to_update=keys,
                                     cur=cur)
 
     @remote_api_endpoint('content/add_metadata')
     @timed
     @process_metrics
     @db_transaction()
     def content_add_metadata(self, content, db=None, cur=None):
         """Add content metadata to the storage (like `content_add`, but
         without inserting to the objstorage).
 
         Args:
             content (iterable): iterable of dictionaries representing
                 individual pieces of content to add. Each dictionary has the
                 following keys:
 
                 - length (int): content length (default: -1)
                 - one key for each checksum algorithm in
                   :data:`swh.model.hashutil.ALGORITHMS`, mapped to the
                   corresponding checksum
                 - status (str): one of visible, hidden, absent
                 - reason (str): if status = absent, the reason why
                 - origin (int): if status = absent, the origin we saw the
                   content in
                 - ctime (datetime): time of insertion in the archive
 
         Returns:
             Summary dict with the following key and associated values:
 
                 content:add: New contents added
                 skipped_content:add: New skipped contents (no data) added
         """
 
         content = [self._normalize_content(c) for c in content]
         for c in content:
             self._validate_content(c)
 
         (content_with_data, content_without_data, summary) = \
             self._filter_new_content(content, db, cur)
 
         if self.journal_writer:
             for item in itertools.chain(content_with_data,
                                         content_without_data):
                 assert 'data' not in content
                 self.journal_writer.write_addition('content', item)
 
         self._content_add_metadata(
             db, cur, content_with_data, content_without_data)
 
         return summary
 
     @remote_api_endpoint('content/data')
     @timed
     def content_get(self, content):
         """Retrieve in bulk contents and their data.
 
         This generator yields exactly as many items than provided sha1
         identifiers, but callers should not assume this will always be true.
 
         It may also yield `None` values in case an object was not found.
 
         Args:
             content: iterables of sha1
 
         Yields:
             Dict[str, bytes]: Generates streams of contents as dict with their
                 raw data:
 
                 - sha1 (bytes): content id
                 - data (bytes): content's raw data
 
         Raises:
             ValueError in case of too much contents are required.
             cf. BULK_BLOCK_CONTENT_LEN_MAX
 
         """
         # FIXME: Make this method support slicing the `data`.
         if len(content) > BULK_BLOCK_CONTENT_LEN_MAX:
             raise ValueError(
                 "Send at maximum %s contents." % BULK_BLOCK_CONTENT_LEN_MAX)
 
         for obj_id in content:
             try:
                 data = self.objstorage.get(obj_id)
             except ObjNotFoundError:
                 yield None
                 continue
 
             yield {'sha1': obj_id, 'data': data}
 
     @remote_api_endpoint('content/range')
     @timed
     @db_transaction()
     def content_get_range(self, start, end, limit=1000, db=None, cur=None):
         """Retrieve contents within range [start, end] bound by limit.
 
         Note that this function may return more than one blob per hash. The
         limit is enforced with multiplicity (ie. two blobs with the same hash
         will count twice toward the limit).
 
         Args:
             **start** (bytes): Starting identifier range (expected smaller
                            than end)
             **end** (bytes): Ending identifier range (expected larger
                              than start)
             **limit** (int): Limit result (default to 1000)
 
         Returns:
             a dict with keys:
             - contents [dict]: iterable of contents in between the range.
             - next (bytes): There remains content in the range
               starting from this next sha1
 
         """
         if limit is None:
             raise ValueError('Development error: limit should not be None')
         contents = []
         next_content = None
         for counter, content_row in enumerate(
                 db.content_get_range(start, end, limit+1, cur)):
             content = dict(zip(db.content_get_metadata_keys, content_row))
             if counter >= limit:
                 # take the last commit for the next page starting from this
                 next_content = content['sha1']
                 break
             contents.append(content)
         return {
             'contents': contents,
             'next': next_content,
         }
 
     @remote_api_endpoint('content/metadata')
     @timed
     @db_transaction_generator(statement_timeout=500)
     def content_get_metadata(self, content, db=None, cur=None):
         """Retrieve content metadata in bulk
 
         Args:
             content: iterable of content identifiers (sha1)
 
         Returns:
             an iterable with content metadata corresponding to the given ids
         """
         for metadata in db.content_get_metadata_from_sha1s(content, cur):
             yield dict(zip(db.content_get_metadata_keys, metadata))
 
     @remote_api_endpoint('content/missing')
     @timed
     @db_transaction_generator()
     def content_missing(self, content, key_hash='sha1', db=None, cur=None):
         """List content missing from storage
 
         Args:
             content ([dict]): iterable of dictionaries whose keys are
                               either 'length' or an item of
                               :data:`swh.model.hashutil.ALGORITHMS`;
                               mapped to the corresponding checksum
                               (or length).
 
             key_hash (str): name of the column to use as hash id
                             result (default: 'sha1')
 
         Returns:
             iterable ([bytes]): missing content ids (as per the
             key_hash column)
 
         Raises:
             TODO: an exception when we get a hash collision.
 
         """
         keys = db.content_hash_keys
 
         if key_hash not in keys:
             raise ValueError("key_hash should be one of %s" % keys)
 
         key_hash_idx = keys.index(key_hash)
 
         if not content:
             return
 
         for obj in db.content_missing_from_list(content, cur):
             yield obj[key_hash_idx]
 
     @remote_api_endpoint('content/missing/sha1')
     @timed
     @db_transaction_generator()
     def content_missing_per_sha1(self, contents, db=None, cur=None):
         """List content missing from storage based only on sha1.
 
         Args:
             contents: Iterable of sha1 to check for absence.
 
         Returns:
             iterable: missing ids
 
         Raises:
             TODO: an exception when we get a hash collision.
 
         """
         for obj in db.content_missing_per_sha1(contents, cur):
             yield obj[0]
 
     @remote_api_endpoint('content/skipped/missing')
     @timed
     @db_transaction_generator()
     def skipped_content_missing(self, contents, db=None, cur=None):
         """List skipped_content missing from storage
 
         Args:
             content: iterable of dictionaries containing the data for each
                 checksum algorithm.
 
         Returns:
             iterable: missing signatures
 
         """
         for content in db.skipped_content_missing(contents, cur):
             yield dict(zip(db.content_hash_keys, content))
 
     @remote_api_endpoint('content/present')
     @timed
     @db_transaction()
     def content_find(self, content, db=None, cur=None):
         """Find a content hash in db.
 
         Args:
             content: a dictionary representing one content hash, mapping
                 checksum algorithm names (see swh.model.hashutil.ALGORITHMS) to
                 checksum values
 
         Returns:
             a triplet (sha1, sha1_git, sha256) if the content exist
             or None otherwise.
 
         Raises:
             ValueError: in case the key of the dictionary is not sha1, sha1_git
                 nor sha256.
 
         """
         if not set(content).intersection(ALGORITHMS):
             raise ValueError('content keys must contain at least one of: '
                              'sha1, sha1_git, sha256, blake2s256')
 
         contents = db.content_find(sha1=content.get('sha1'),
                                    sha1_git=content.get('sha1_git'),
                                    sha256=content.get('sha256'),
                                    blake2s256=content.get('blake2s256'),
                                    cur=cur)
         return [dict(zip(db.content_find_cols, content))
                 for content in contents]
 
     @remote_api_endpoint('content/get_random')
     @timed
     @db_transaction()
     def content_get_random(self, db=None, cur=None):
         """Finds a random content id.
 
         Returns:
             a sha1_git
         """
         return db.content_get_random(cur)
 
     @remote_api_endpoint('directory/add')
     @timed
     @process_metrics
     @db_transaction()
     def directory_add(self, directories, db=None, cur=None):
         """Add directories to the storage
 
         Args:
             directories (iterable): iterable of dictionaries representing the
                 individual directories to add. Each dict has the following
                 keys:
 
                 - id (sha1_git): the id of the directory to add
                 - entries (list): list of dicts for each entry in the
                       directory.  Each dict has the following keys:
 
                       - name (bytes)
                       - type (one of 'file', 'dir', 'rev'): type of the
                         directory entry (file, directory, revision)
                       - target (sha1_git): id of the object pointed at by the
                         directory entry
                       - perms (int): entry permissions
 
         Returns:
             Summary dict of keys with associated count as values:
 
                 directory:add: Number of directories actually added
 
         """
         summary = {'directory:add': 0}
 
         dirs = set()
         dir_entries = {
             'file': defaultdict(list),
             'dir': defaultdict(list),
             'rev': defaultdict(list),
         }
 
         for cur_dir in directories:
             dir_id = cur_dir['id']
             dirs.add(dir_id)
             for src_entry in cur_dir['entries']:
                 entry = src_entry.copy()
                 entry['dir_id'] = dir_id
                 if entry['type'] not in ('file', 'dir', 'rev'):
                     raise ValueError(
                         'Entry type must be file, dir, or rev; not %s'
                         % entry['type'])
                 dir_entries[entry['type']][dir_id].append(entry)
 
         dirs_missing = set(self.directory_missing(dirs, db=db, cur=cur))
         if not dirs_missing:
             return summary
 
         if self.journal_writer:
             self.journal_writer.write_additions(
                 'directory',
                 (dir_ for dir_ in directories
                  if dir_['id'] in dirs_missing))
 
         # Copy directory ids
         dirs_missing_dict = ({'id': dir} for dir in dirs_missing)
         db.mktemp('directory', cur)
         db.copy_to(dirs_missing_dict, 'tmp_directory', ['id'], cur)
 
         # Copy entries
         for entry_type, entry_list in dir_entries.items():
             entries = itertools.chain.from_iterable(
                 entries_for_dir
                 for dir_id, entries_for_dir
                 in entry_list.items()
                 if dir_id in dirs_missing)
 
             db.mktemp_dir_entry(entry_type)
 
             db.copy_to(
                 entries,
                 'tmp_directory_entry_%s' % entry_type,
                 ['target', 'name', 'perms', 'dir_id'],
                 cur,
             )
 
         # Do the final copy
         db.directory_add_from_temp(cur)
         summary['directory:add'] = len(dirs_missing)
 
         return summary
 
     @remote_api_endpoint('directory/missing')
     @timed
     @db_transaction_generator()
     def directory_missing(self, directories, db=None, cur=None):
         """List directories missing from storage
 
         Args:
             directories (iterable): an iterable of directory ids
 
         Yields:
             missing directory ids
 
         """
         for obj in db.directory_missing_from_list(directories, cur):
             yield obj[0]
 
     @remote_api_endpoint('directory/ls')
     @timed
     @db_transaction_generator(statement_timeout=20000)
     def directory_ls(self, directory, recursive=False, db=None, cur=None):
         """Get entries for one directory.
 
         Args:
             - directory: the directory to list entries from.
             - recursive: if flag on, this list recursively from this directory.
 
         Returns:
             List of entries for such directory.
 
         If `recursive=True`, names in the path of a dir/file not at the
         root are concatenated with a slash (`/`).
 
         """
         if recursive:
             res_gen = db.directory_walk(directory, cur=cur)
         else:
             res_gen = db.directory_walk_one(directory, cur=cur)
 
         for line in res_gen:
             yield dict(zip(db.directory_ls_cols, line))
 
     @remote_api_endpoint('directory/path')
     @timed
     @db_transaction(statement_timeout=2000)
     def directory_entry_get_by_path(self, directory, paths, db=None, cur=None):
         """Get the directory entry (either file or dir) from directory with path.
 
         Args:
             - directory: sha1 of the top level directory
             - paths: path to lookup from the top level directory. From left
               (top) to right (bottom).
 
         Returns:
             The corresponding directory entry if found, None otherwise.
 
         """
         res = db.directory_entry_get_by_path(directory, paths, cur)
         if res:
             return dict(zip(db.directory_ls_cols, res))
 
     @remote_api_endpoint('directory/get_random')
     @timed
     @db_transaction()
     def directory_get_random(self, db=None, cur=None):
         """Finds a random directory id.
 
         Returns:
             a sha1_git
         """
         return db.directory_get_random(cur)
 
     @remote_api_endpoint('revision/add')
     @timed
     @process_metrics
     @db_transaction()
     def revision_add(self, revisions, db=None, cur=None):
         """Add revisions to the storage
 
         Args:
             revisions (Iterable[dict]): iterable of dictionaries representing
                 the individual revisions to add. Each dict has the following
                 keys:
 
                 - **id** (:class:`sha1_git`): id of the revision to add
                 - **date** (:class:`dict`): date the revision was written
                 - **committer_date** (:class:`dict`): date the revision got
                   added to the origin
                 - **type** (one of 'git', 'tar'): type of the
                   revision added
                 - **directory** (:class:`sha1_git`): the directory the
                   revision points at
                 - **message** (:class:`bytes`): the message associated with
                   the revision
                 - **author** (:class:`Dict[str, bytes]`): dictionary with
                   keys: name, fullname, email
                 - **committer** (:class:`Dict[str, bytes]`): dictionary with
                   keys: name, fullname, email
                 - **metadata** (:class:`jsonb`): extra information as
                   dictionary
                 - **synthetic** (:class:`bool`): revision's nature (tarball,
                   directory creates synthetic revision`)
                 - **parents** (:class:`list[sha1_git]`): the parents of
                   this revision
 
         date dictionaries have the form defined in :mod:`swh.model`.
 
         Returns:
             Summary dict of keys with associated count as values
 
                 revision:add: New objects actually stored in db
 
         """
         summary = {'revision:add': 0}
 
         revisions_missing = set(self.revision_missing(
             set(revision['id'] for revision in revisions),
             db=db, cur=cur))
 
         if not revisions_missing:
             return summary
 
         db.mktemp_revision(cur)
 
         revisions_filtered = [
             revision for revision in revisions
             if revision['id'] in revisions_missing]
 
         if self.journal_writer:
             self.journal_writer.write_additions('revision', revisions_filtered)
 
         revisions_filtered = map(converters.revision_to_db, revisions_filtered)
 
         parents_filtered = []
 
         db.copy_to(
             revisions_filtered, 'tmp_revision', db.revision_add_cols,
             cur,
             lambda rev: parents_filtered.extend(rev['parents']))
 
         db.revision_add_from_temp(cur)
 
         db.copy_to(parents_filtered, 'revision_history',
                    ['id', 'parent_id', 'parent_rank'], cur)
 
         return {'revision:add': len(revisions_missing)}
 
     @remote_api_endpoint('revision/missing')
     @timed
     @db_transaction_generator()
     def revision_missing(self, revisions, db=None, cur=None):
         """List revisions missing from storage
 
         Args:
             revisions (iterable): revision ids
 
         Yields:
             missing revision ids
 
         """
         if not revisions:
             return
 
         for obj in db.revision_missing_from_list(revisions, cur):
             yield obj[0]
 
     @remote_api_endpoint('revision')
     @timed
     @db_transaction_generator(statement_timeout=1000)
     def revision_get(self, revisions, db=None, cur=None):
         """Get all revisions from storage
 
         Args:
             revisions: an iterable of revision ids
 
         Returns:
             iterable: an iterable of revisions as dictionaries (or None if the
                 revision doesn't exist)
 
         """
         for line in db.revision_get_from_list(revisions, cur):
             data = converters.db_to_revision(
                 dict(zip(db.revision_get_cols, line))
             )
             if not data['type']:
                 yield None
                 continue
             yield data
 
     @remote_api_endpoint('revision/log')
     @timed
     @db_transaction_generator(statement_timeout=2000)
     def revision_log(self, revisions, limit=None, db=None, cur=None):
         """Fetch revision entry from the given root revisions.
 
         Args:
             revisions: array of root revision to lookup
             limit: limitation on the output result. Default to None.
 
         Yields:
             List of revision log from such revisions root.
 
         """
         for line in db.revision_log(revisions, limit, cur):
             data = converters.db_to_revision(
                 dict(zip(db.revision_get_cols, line))
             )
             if not data['type']:
                 yield None
                 continue
             yield data
 
     @remote_api_endpoint('revision/shortlog')
     @timed
     @db_transaction_generator(statement_timeout=2000)
     def revision_shortlog(self, revisions, limit=None, db=None, cur=None):
         """Fetch the shortlog for the given revisions
 
         Args:
             revisions: list of root revisions to lookup
             limit: depth limitation for the output
 
         Yields:
             a list of (id, parents) tuples.
 
         """
 
         yield from db.revision_shortlog(revisions, limit, cur)
 
     @remote_api_endpoint('revision/get_random')
     @timed
     @db_transaction()
     def revision_get_random(self, db=None, cur=None):
         """Finds a random revision id.
 
         Returns:
             a sha1_git
         """
         return db.revision_get_random(cur)
 
     @remote_api_endpoint('release/add')
     @timed
     @process_metrics
     @db_transaction()
     def release_add(self, releases, db=None, cur=None):
         """Add releases to the storage
 
         Args:
             releases (Iterable[dict]): iterable of dictionaries representing
                 the individual releases to add. Each dict has the following
                 keys:
 
                 - **id** (:class:`sha1_git`): id of the release to add
                 - **revision** (:class:`sha1_git`): id of the revision the
                   release points to
                 - **date** (:class:`dict`): the date the release was made
                 - **name** (:class:`bytes`): the name of the release
                 - **comment** (:class:`bytes`): the comment associated with
                   the release
                 - **author** (:class:`Dict[str, bytes]`): dictionary with
                   keys: name, fullname, email
 
         the date dictionary has the form defined in :mod:`swh.model`.
 
         Returns:
             Summary dict of keys with associated count as values
 
                 release:add: New objects contents actually stored in db
 
         """
         summary = {'release:add': 0}
 
         release_ids = set(release['id'] for release in releases)
         releases_missing = set(self.release_missing(release_ids,
                                                     db=db, cur=cur))
 
         if not releases_missing:
             return summary
 
         db.mktemp_release(cur)
 
         releases_missing = list(releases_missing)
 
         releases_filtered = [
             release for release in releases
             if release['id'] in releases_missing
         ]
 
         if self.journal_writer:
             self.journal_writer.write_additions('release', releases_filtered)
 
         releases_filtered = map(converters.release_to_db, releases_filtered)
 
         db.copy_to(releases_filtered, 'tmp_release', db.release_add_cols,
                    cur)
 
         db.release_add_from_temp(cur)
 
         return {'release:add': len(releases_missing)}
 
     @remote_api_endpoint('release/missing')
     @timed
     @db_transaction_generator()
     def release_missing(self, releases, db=None, cur=None):
         """List releases missing from storage
 
         Args:
             releases: an iterable of release ids
 
         Returns:
             a list of missing release ids
 
         """
         if not releases:
             return
 
         for obj in db.release_missing_from_list(releases, cur):
             yield obj[0]
 
     @remote_api_endpoint('release')
     @timed
     @db_transaction_generator(statement_timeout=500)
     def release_get(self, releases, db=None, cur=None):
         """Given a list of sha1, return the releases's information
 
         Args:
             releases: list of sha1s
 
         Yields:
             dicts with the same keys as those given to `release_add`
             (or ``None`` if a release does not exist)
 
         """
         for release in db.release_get_from_list(releases, cur):
             data = converters.db_to_release(
                 dict(zip(db.release_get_cols, release))
             )
             yield data if data['target_type'] else None
 
     @remote_api_endpoint('release/get_random')
     @timed
     @db_transaction()
     def release_get_random(self, db=None, cur=None):
         """Finds a random release id.
 
         Returns:
             a sha1_git
         """
         return db.release_get_random(cur)
 
     @remote_api_endpoint('snapshot/add')
     @timed
     @process_metrics
     @db_transaction()
     def snapshot_add(self, snapshots, db=None, cur=None):
         """Add snapshots to the storage.
 
         Args:
             snapshot ([dict]): the snapshots to add, containing the
               following keys:
 
               - **id** (:class:`bytes`): id of the snapshot
               - **branches** (:class:`dict`): branches the snapshot contains,
                 mapping the branch name (:class:`bytes`) to the branch target,
                 itself a :class:`dict` (or ``None`` if the branch points to an
                 unknown object)
 
                 - **target_type** (:class:`str`): one of ``content``,
                   ``directory``, ``revision``, ``release``,
                   ``snapshot``, ``alias``
                 - **target** (:class:`bytes`): identifier of the target
                   (currently a ``sha1_git`` for all object kinds, or the name
                   of the target branch for aliases)
 
         Raises:
             ValueError: if the origin or visit id does not exist.
 
         Returns:
 
             Summary dict of keys with associated count as values
 
                 snapshot:add: Count of object actually stored in db
 
         """
         created_temp_table = False
 
         count = 0
         for snapshot in snapshots:
             if not db.snapshot_exists(snapshot['id'], cur):
                 if not created_temp_table:
                     db.mktemp_snapshot_branch(cur)
                     created_temp_table = True
 
                 db.copy_to(
                     (
                         {
                             'name': name,
                             'target': info['target'] if info else None,
                             'target_type': (info['target_type']
                                             if info else None),
                         }
                         for name, info in snapshot['branches'].items()
                     ),
                     'tmp_snapshot_branch',
                     ['name', 'target', 'target_type'],
                     cur,
                 )
 
                 if self.journal_writer:
                     self.journal_writer.write_addition('snapshot', snapshot)
 
                 db.snapshot_add(snapshot['id'], cur)
                 count += 1
 
         return {'snapshot:add': count}
 
     @remote_api_endpoint('snapshot')
     @timed
     @db_transaction(statement_timeout=2000)
     def snapshot_get(self, snapshot_id, db=None, cur=None):
         """Get the content, possibly partial, of a snapshot with the given id
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         .. warning:: At most 1000 branches contained in the snapshot will be
             returned for performance reasons. In order to browse the whole
             set of branches, the method :meth:`snapshot_get_branches`
             should be used instead.
 
         Args:
             snapshot_id (bytes): identifier of the snapshot
         Returns:
             dict: a dict with three keys:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than 1000
                   branches.
         """
 
         return self.snapshot_get_branches(snapshot_id, db=db, cur=cur)
 
     @remote_api_endpoint('snapshot/by_origin_visit')
     @timed
     @db_transaction(statement_timeout=2000)
     def snapshot_get_by_origin_visit(self, origin, visit, db=None, cur=None):
         """Get the content, possibly partial, of a snapshot for the given origin visit
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         .. warning:: At most 1000 branches contained in the snapshot will be
             returned for performance reasons. In order to browse the whole
             set of branches, the method :meth:`snapshot_get_branches`
             should be used instead.
 
         Args:
             origin (int): the origin identifier
             visit (int): the visit identifier
         Returns:
             dict: None if the snapshot does not exist;
               a dict with three keys otherwise:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than 1000
                   branches.
 
         """
         snapshot_id = db.snapshot_get_by_origin_visit(origin, visit, cur)
 
         if snapshot_id:
             return self.snapshot_get(snapshot_id, db=db, cur=cur)
 
         return None
 
     @remote_api_endpoint('snapshot/latest')
     @timed
     @db_transaction(statement_timeout=4000)
     def snapshot_get_latest(self, origin, allowed_statuses=None, db=None,
                             cur=None):
         """Get the content, possibly partial, of the latest snapshot for the
         given origin, optionally only from visits that have one of the given
         allowed_statuses
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         .. warning:: At most 1000 branches contained in the snapshot will be
             returned for performance reasons. In order to browse the whole
             set of branches, the method :meth:`snapshot_get_branches`
             should be used instead.
 
         Args:
             origin (str): the origin's URL
             allowed_statuses (list of str): list of visit statuses considered
                 to find the latest snapshot for the visit. For instance,
                 ``allowed_statuses=['full']`` will only consider visits that
                 have successfully run to completion.
         Returns:
             dict: a dict with three keys:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than 1000
                   branches.
         """
         if isinstance(origin, int):
             origin = self.origin_get({'id': origin}, db=db, cur=cur)
             if not origin:
                 return
             origin = origin['url']
 
         origin_visit = self.origin_visit_get_latest(
             origin, allowed_statuses=allowed_statuses, require_snapshot=True,
             db=db, cur=cur)
         if origin_visit and origin_visit['snapshot']:
             snapshot = self.snapshot_get(
                     origin_visit['snapshot'], db=db, cur=cur)
             if not snapshot:
                 raise ValueError(
                     'last origin visit references an unknown snapshot')
             return snapshot
 
     @remote_api_endpoint('snapshot/count_branches')
     @timed
     @db_transaction(statement_timeout=2000)
     def snapshot_count_branches(self, snapshot_id, db=None, cur=None):
         """Count the number of branches in the snapshot with the given id
 
         Args:
             snapshot_id (bytes): identifier of the snapshot
 
         Returns:
             dict: A dict whose keys are the target types of branches and
             values their corresponding amount
         """
         return dict([bc for bc in
                      db.snapshot_count_branches(snapshot_id, cur)])
 
     @remote_api_endpoint('snapshot/get_branches')
     @timed
     @db_transaction(statement_timeout=2000)
     def snapshot_get_branches(self, snapshot_id, branches_from=b'',
                               branches_count=1000, target_types=None,
                               db=None, cur=None):
         """Get the content, possibly partial, of a snapshot with the given id
 
         The branches of the snapshot are iterated in the lexicographical
         order of their names.
 
         Args:
             snapshot_id (bytes): identifier of the snapshot
             branches_from (bytes): optional parameter used to skip branches
                 whose name is lesser than it before returning them
             branches_count (int): optional parameter used to restrain
                 the amount of returned branches
             target_types (list): optional parameter used to filter the
                 target types of branch to return (possible values that can be
                 contained in that list are `'content', 'directory',
                 'revision', 'release', 'snapshot', 'alias'`)
         Returns:
             dict: None if the snapshot does not exist;
               a dict with three keys otherwise:
                 * **id**: identifier of the snapshot
                 * **branches**: a dict of branches contained in the snapshot
                   whose keys are the branches' names.
                 * **next_branch**: the name of the first branch not returned
                   or :const:`None` if the snapshot has less than
                   `branches_count` branches after `branches_from` included.
         """
         if snapshot_id == EMPTY_SNAPSHOT_ID:
             return {
                 'id': snapshot_id,
                 'branches': {},
                 'next_branch': None,
             }
 
         branches = {}
         next_branch = None
 
         fetched_branches = list(db.snapshot_get_by_id(
             snapshot_id, branches_from=branches_from,
             branches_count=branches_count+1, target_types=target_types,
             cur=cur,
         ))
         for branch in fetched_branches[:branches_count]:
             branch = dict(zip(db.snapshot_get_cols, branch))
             del branch['snapshot_id']
             name = branch.pop('name')
             if branch == {'target': None, 'target_type': None}:
                 branch = None
             branches[name] = branch
 
         if len(fetched_branches) > branches_count:
             branch = dict(zip(db.snapshot_get_cols, fetched_branches[-1]))
             next_branch = branch['name']
 
         if branches:
             return {
                 'id': snapshot_id,
                 'branches': branches,
                 'next_branch': next_branch,
             }
 
         return None
 
     @remote_api_endpoint('snapshot/get_random')
     @timed
     @db_transaction()
     def snapshot_get_random(self, db=None, cur=None):
         """Finds a random snapshot id.
 
         Returns:
             a sha1_git
         """
         return db.snapshot_get_random(cur)
 
     @remote_api_endpoint('origin/visit/add')
     @timed
     @db_transaction()
     def origin_visit_add(self, origin, date, type,
                          db=None, cur=None):
         """Add an origin_visit for the origin at ts with status 'ongoing'.
 
         Args:
             origin (str): visited origin's identifier or URL
             date (Union[str,datetime]): timestamp of such visit
             type (str): the type of loader used for the visit (hg, git, ...)
 
         Returns:
             dict: dictionary with keys origin and visit where:
 
             - origin: origin identifier
             - visit: the visit identifier for the new visit occurrence
 
         """
         origin_url = origin
 
         if isinstance(date, str):
             # FIXME: Converge on iso8601 at some point
             date = dateutil.parser.parse(date)
 
         visit_id = db.origin_visit_add(origin_url, date, type, cur)
 
         if self.journal_writer:
             # We can write to the journal only after inserting to the
             # DB, because we want the id of the visit
             self.journal_writer.write_addition('origin_visit', {
                 'origin': origin_url, 'date': date, 'type': type,
                 'visit': visit_id,
                 'status': 'ongoing', 'metadata': None, 'snapshot': None})
 
         send_metric('origin_visit:add', count=1, method_name='origin_visit')
         return {
             'origin': origin_url,
             'visit': visit_id,
         }
 
     @remote_api_endpoint('origin/visit/update')
     @timed
     @db_transaction()
     def origin_visit_update(self, origin, visit_id, status=None,
                             metadata=None, snapshot=None,
                             db=None, cur=None):
         """Update an origin_visit's status.
 
         Args:
             origin (str): visited origin's URL
             visit_id: Visit's id
             status: Visit's new status
             metadata: Data associated to the visit
             snapshot (sha1_git): identifier of the snapshot to add to
                 the visit
 
         Returns:
             None
 
         """
         if not isinstance(origin, str):
             raise TypeError('origin must be a string, not %r' % (origin,))
         origin_url = origin
         visit = db.origin_visit_get(origin_url, visit_id, cur=cur)
 
         if not visit:
             raise ValueError('Invalid visit_id for this origin.')
 
         visit = dict(zip(db.origin_visit_get_cols, visit))
 
         updates = {}
         if status and status != visit['status']:
             updates['status'] = status
         if metadata and metadata != visit['metadata']:
             updates['metadata'] = metadata
         if snapshot and snapshot != visit['snapshot']:
             updates['snapshot'] = snapshot
 
         if updates:
             if self.journal_writer:
                 self.journal_writer.write_update('origin_visit', {
                     **visit, **updates})
 
             db.origin_visit_update(origin_url, visit_id, updates, cur)
 
     @remote_api_endpoint('origin/visit/upsert')
     @timed
     @db_transaction()
     def origin_visit_upsert(self, visits, db=None, cur=None):
         """Add a origin_visits with a specific id and with all its data.
         If there is already an origin_visit with the same
         `(origin_id, visit_id)`, overwrites it.
 
         Args:
             visits: iterable of dicts with keys:
 
                 origin: dict with keys either `id` or `url`
                 visit: origin visit id
                 date: timestamp of such visit
                 status: Visit's new status
                 metadata: Data associated to the visit
                 snapshot (sha1_git): identifier of the snapshot to add to
                     the visit
         """
         visits = copy.deepcopy(visits)
         for visit in visits:
             if isinstance(visit['date'], str):
                 visit['date'] = dateutil.parser.parse(visit['date'])
             if not isinstance(visit['origin'], str):
                 raise TypeError("visit['origin'] must be a string, not %r"
                                 % (visit['origin'],))
 
         if self.journal_writer:
             for visit in visits:
                 self.journal_writer.write_addition('origin_visit', visit)
 
         for visit in visits:
             # TODO: upsert them all in a single query
             db.origin_visit_upsert(**visit, cur=cur)
 
     @remote_api_endpoint('origin/visit/get')
     @timed
     @db_transaction_generator(statement_timeout=500)
     def origin_visit_get(self, origin, last_visit=None, limit=None, db=None,
                          cur=None):
         """Retrieve all the origin's visit's information.
 
         Args:
             origin (str): The visited origin
             last_visit: Starting point from which listing the next visits
                 Default to None
             limit (int): Number of results to return from the last visit.
                 Default to None
 
         Yields:
             List of visits.
 
         """
         for line in db.origin_visit_get_all(
                 origin, last_visit=last_visit, limit=limit, cur=cur):
             data = dict(zip(db.origin_visit_get_cols, line))
             yield data
 
     @remote_api_endpoint('origin/visit/find_by_date')
     @timed
     @db_transaction(statement_timeout=500)
     def origin_visit_find_by_date(self, origin, visit_date, db=None, cur=None):
         """Retrieves the origin visit whose date is closest to the provided
         timestamp.
         In case of a tie, the visit with largest id is selected.
 
         Args:
             origin (str): The occurrence's origin (URL).
             target (datetime): target timestamp
 
         Returns:
             A visit.
 
         """
         line = db.origin_visit_find_by_date(origin, visit_date, cur=cur)
         if line:
             return dict(zip(db.origin_visit_get_cols, line))
 
     @remote_api_endpoint('origin/visit/getby')
     @timed
     @db_transaction(statement_timeout=500)
     def origin_visit_get_by(self, origin, visit, db=None, cur=None):
         """Retrieve origin visit's information.
 
         Args:
             origin: The occurrence's origin (identifier).
 
         Returns:
             The information on that particular (origin, visit) or None if
             it does not exist
 
         """
         ori_visit = db.origin_visit_get(origin, visit, cur)
         if not ori_visit:
             return None
 
         return dict(zip(db.origin_visit_get_cols, ori_visit))
 
     @remote_api_endpoint('origin/visit/get_latest')
     @timed
     @db_transaction(statement_timeout=4000)
     def origin_visit_get_latest(
             self, origin, allowed_statuses=None, require_snapshot=False,
             db=None, cur=None):
         """Get the latest origin visit for the given origin, optionally
         looking only for those with one of the given allowed_statuses
         or for those with a known snapshot.
 
         Args:
             origin (str): the origin's URL
             allowed_statuses (list of str): list of visit statuses considered
                 to find the latest visit. For instance,
                 ``allowed_statuses=['full']`` will only consider visits that
                 have successfully run to completion.
             require_snapshot (bool): If True, only a visit with a snapshot
                 will be returned.
         Returns:
             dict: a dict with the following keys:
 
                 origin: the URL of the origin
                 visit: origin visit id
                 type: type of loader used for the visit
                 date: timestamp of such visit
                 status: Visit's new status
                 metadata: Data associated to the visit
                 snapshot (Optional[sha1_git]): identifier of the snapshot
                     associated to the visit
         """
         origin_visit = db.origin_visit_get_latest(
             origin, allowed_statuses=allowed_statuses,
             require_snapshot=require_snapshot, cur=cur)
         if origin_visit:
             return dict(zip(db.origin_visit_get_cols, origin_visit))
 
     @remote_api_endpoint('origin/visit/get_random')
     @timed
     @db_transaction()
     def origin_visit_get_random(
             self, type: str, db=None, cur=None) -> Mapping[str, Any]:
         """Randomly select one successful origin visit with <type>
         made in the last 3 months.
 
         Returns:
             dict representing an origin visit, in the same format as
             :py:meth:`origin_visit_get`.
 
         """
         data: Dict[str, Any] = {}
         result = db.origin_visit_get_random(type, cur)
         if result:
             data = dict(zip(db.origin_visit_get_cols, result))
         return data
 
     @remote_api_endpoint('object/find_by_sha1_git')
     @timed
     @db_transaction(statement_timeout=2000)
     def object_find_by_sha1_git(self, ids, db=None, cur=None):
         """Return the objects found with the given ids.
 
         Args:
             ids: a generator of sha1_gits
 
         Returns:
             dict: a mapping from id to the list of objects found. Each object
             found is itself a dict with keys:
 
             - sha1_git: the input id
             - type: the type of object found
             - id: the id of the object found
             - object_id: the numeric id of the object found.
 
         """
         ret = {id: [] for id in ids}
 
         for retval in db.object_find_by_sha1_git(ids, cur=cur):
             if retval[1]:
                 ret[retval[0]].append(dict(zip(db.object_find_by_sha1_git_cols,
                                                retval)))
 
         return ret
 
     @remote_api_endpoint('origin/get')
     @timed
     @db_transaction(statement_timeout=500)
     def origin_get(self, origins, db=None, cur=None):
         """Return origins, either all identified by their ids or all
         identified by tuples (type, url).
 
         If the url is given and the type is omitted, one of the origins with
         that url is returned.
 
         Args:
             origin: a list of dictionaries representing the individual
                 origins to find.
                 These dicts have the key url:
 
                 - url (bytes): the url the origin points to
 
         Returns:
             dict: the origin dictionary with the keys:
 
             - id: origin's id
             - url: origin's url
 
         Raises:
             ValueError: if the url or the id don't exist.
 
         """
         if isinstance(origins, dict):
             # Old API
             return_single = True
             origins = [origins]
         elif len(origins) == 0:
             return []
         else:
             return_single = False
 
         origin_urls = [origin['url'] for origin in origins]
         results = db.origin_get_by_url(origin_urls, cur)
 
         results = [dict(zip(db.origin_cols, result))
                    for result in results]
         if return_single:
             assert len(results) == 1
             if results[0]['url'] is not None:
                 return results[0]
             else:
                 return None
         else:
             return [None if res['url'] is None else res for res in results]
 
     @remote_api_endpoint('origin/get_sha1')
     @timed
     @db_transaction_generator(statement_timeout=500)
     def origin_get_by_sha1(self, sha1s, db=None, cur=None):
         """Return origins, identified by the sha1 of their URLs.
 
         Args:
             sha1s (list[bytes]): a list of sha1s
 
         Yields:
             dicts containing origin information as returned
             by :meth:`swh.storage.storage.Storage.origin_get`, or None if an
             origin matching the sha1 is not found.
 
         """
         for line in db.origin_get_by_sha1(sha1s, cur):
             if line[0] is not None:
                 yield dict(zip(db.origin_cols, line))
             else:
                 yield None
 
     @remote_api_endpoint('origin/get_range')
     @timed
     @db_transaction_generator()
     def origin_get_range(self, origin_from=1, origin_count=100,
                          db=None, cur=None):
         """Retrieve ``origin_count`` origins whose ids are greater
         or equal than ``origin_from``.
 
         Origins are sorted by id before retrieving them.
 
         Args:
             origin_from (int): the minimum id of origins to retrieve
             origin_count (int): the maximum number of origins to retrieve
 
         Yields:
             dicts containing origin information as returned
             by :meth:`swh.storage.storage.Storage.origin_get`.
         """
         for origin in db.origin_get_range(origin_from, origin_count, cur):
             yield dict(zip(db.origin_get_range_cols, origin))
 
+    @remote_api_endpoint('origin/list')
+    @timed
+    @db_transaction()
+    def origin_list(self, page_token: Optional[str] = None, limit: int = 100,
+                    *, db=None, cur=None) -> dict:
+        """Returns the list of origins
+
+        Args:
+            page_token: opaque token used for pagination.
+            limit: the maximum number of results to return
+
+        Returns:
+            dict: dict with the following keys:
+              - **next_page_token** (str, optional): opaque token to be used as
+                `page_token` for retrieving the next page. if absent, there is
+                no more pages to gather.
+              - **origins** (List[dict]): list of origins, as returned by
+                `origin_get`.
+        """
+        page_token = page_token or '0'
+        if not isinstance(page_token, str):
+            raise TypeError('page_token must be a string.')
+        origin_from = int(page_token)
+        result: Dict[str, Any] = {
+            'origins': [
+                dict(zip(db.origin_get_range_cols, origin))
+                for origin in db.origin_get_range(origin_from, limit, cur)
+            ],
+        }
+
+        assert len(result['origins']) <= limit
+        if len(result['origins']) == limit:
+            result['next_page_token'] = str(result['origins'][limit-1]['id']+1)
+
+        for origin in result['origins']:
+            del origin['id']
+
+        return result
+
     @remote_api_endpoint('origin/search')
     @timed
     @db_transaction_generator()
     def origin_search(self, url_pattern, offset=0, limit=50,
                       regexp=False, with_visit=False, db=None, cur=None):
         """Search for origins whose urls contain a provided string pattern
         or match a provided regular expression.
         The search is performed in a case insensitive way.
 
         Args:
             url_pattern (str): the string pattern to search for in origin urls
             offset (int): number of found origins to skip before returning
                 results
             limit (int): the maximum number of found origins to return
             regexp (bool): if True, consider the provided pattern as a regular
                 expression and return origins whose urls match it
             with_visit (bool): if True, filter out origins with no visit
 
         Yields:
             dicts containing origin information as returned
             by :meth:`swh.storage.storage.Storage.origin_get`.
         """
         for origin in db.origin_search(url_pattern, offset, limit,
                                        regexp, with_visit, cur):
             yield dict(zip(db.origin_cols, origin))
 
     @remote_api_endpoint('origin/count')
     @timed
     @db_transaction()
     def origin_count(self, url_pattern, regexp=False,
                      with_visit=False, db=None, cur=None):
         """Count origins whose urls contain a provided string pattern
         or match a provided regular expression.
         The pattern search in origin urls is performed in a case insensitive
         way.
 
         Args:
             url_pattern (str): the string pattern to search for in origin urls
             regexp (bool): if True, consider the provided pattern as a regular
                 expression and return origins whose urls match it
             with_visit (bool): if True, filter out origins with no visit
 
         Returns:
             int: The number of origins matching the search criterion.
         """
         return db.origin_count(url_pattern, regexp, with_visit, cur)
 
     @remote_api_endpoint('origin/add_multi')
     @timed
     @db_transaction()
     def origin_add(self, origins, db=None, cur=None):
         """Add origins to the storage
 
         Args:
             origins: list of dictionaries representing the individual origins,
                 with the following keys:
 
                 - type: the origin type ('git', 'svn', 'deb', ...)
                 - url (bytes): the url the origin points to
 
         Returns:
             list: given origins as dict updated with their id
 
         """
         origins = copy.deepcopy(origins)
         for origin in origins:
             self.origin_add_one(origin, db=db, cur=cur)
 
         send_metric('origin:add', count=len(origins), method_name='origin_add')
         return origins
 
     @remote_api_endpoint('origin/add')
     @timed
     @db_transaction()
     def origin_add_one(self, origin, db=None, cur=None):
         """Add origin to the storage
 
         Args:
             origin: dictionary representing the individual origin to add. This
                 dict has the following keys:
 
                 - type (FIXME: enum TBD): the origin type ('git', 'wget', ...)
                 - url (bytes): the url the origin points to
 
         Returns:
             the id of the added origin, or of the identical one that already
             exists.
 
         """
         origin_row = list(db.origin_get_by_url([origin['url']], cur))[0]
         origin_url = dict(zip(db.origin_cols, origin_row))['url']
         if origin_url:
             return origin_url
 
         if self.journal_writer:
             self.journal_writer.write_addition('origin', origin)
 
         origins = db.origin_add(origin['url'], cur)
         send_metric('origin:add', count=len(origins), method_name='origin_add')
         return origins
 
     @db_transaction(statement_timeout=500)
     def stat_counters(self, db=None, cur=None):
         """compute statistics about the number of tuples in various tables
 
         Returns:
             dict: a dictionary mapping textual labels (e.g., content) to
             integer values (e.g., the number of tuples in table content)
 
         """
         return {k: v for (k, v) in db.stat_counters()}
 
     @db_transaction()
     def refresh_stat_counters(self, db=None, cur=None):
         """Recomputes the statistics for `stat_counters`."""
         keys = [
             'content',
             'directory',
             'directory_entry_dir',
             'directory_entry_file',
             'directory_entry_rev',
             'origin',
             'origin_visit',
             'person',
             'release',
             'revision',
             'revision_history',
             'skipped_content',
             'snapshot']
 
         for key in keys:
             cur.execute('select * from swh_update_counter(%s)', (key,))
 
     @remote_api_endpoint('origin/metadata/add')
     @timed
     @db_transaction()
     def origin_metadata_add(self, origin_url, ts, provider, tool, metadata,
                             db=None, cur=None):
         """ Add an origin_metadata for the origin at ts with provenance and
         metadata.
 
         Args:
             origin_url (str): the origin url for which the metadata is added
             ts (datetime): timestamp of the found metadata
             provider (int): the provider of metadata (ex:'hal')
             tool (int): tool used to extract metadata
             metadata (jsonb): the metadata retrieved at the time and location
         """
         if isinstance(ts, str):
             ts = dateutil.parser.parse(ts)
 
         db.origin_metadata_add(origin_url, ts, provider, tool,
                                metadata, cur)
         send_metric(
             'origin_metadata:add', count=1, method_name='origin_metadata_add')
 
     @remote_api_endpoint('origin/metadata/get')
     @timed
     @db_transaction_generator(statement_timeout=500)
     def origin_metadata_get_by(self, origin_url, provider_type=None, db=None,
                                cur=None):
         """Retrieve list of all origin_metadata entries for the origin_id
 
         Args:
             origin_url (str): the origin's URL
             provider_type (str): (optional) type of provider
 
         Returns:
             list of dicts: the origin_metadata dictionary with the keys:
 
             - origin_id (int): origin's id
             - discovery_date (datetime): timestamp of discovery
             - tool_id (int): metadata's extracting tool
             - metadata (jsonb)
             - provider_id (int): metadata's provider
             - provider_name (str)
             - provider_type (str)
             - provider_url (str)
 
         """
         for line in db.origin_metadata_get_by(origin_url, provider_type, cur):
             yield dict(zip(db.origin_metadata_get_cols, line))
 
     @remote_api_endpoint('tool/add')
     @timed
     @db_transaction()
     def tool_add(self, tools, db=None, cur=None):
         """Add new tools to the storage.
 
         Args:
             tools (iterable of :class:`dict`): Tool information to add to
               storage. Each tool is a :class:`dict` with the following keys:
 
               - name (:class:`str`): name of the tool
               - version (:class:`str`): version of the tool
               - configuration (:class:`dict`): configuration of the tool,
                 must be json-encodable
 
         Returns:
             :class:`dict`: All the tools inserted in storage
             (including the internal ``id``). The order of the list is not
             guaranteed to match the order of the initial list.
 
         """
         db.mktemp_tool(cur)
         db.copy_to(tools, 'tmp_tool',
                    ['name', 'version', 'configuration'],
                    cur)
 
         tools = db.tool_add_from_temp(cur)
         results = [dict(zip(db.tool_cols, line)) for line in tools]
         send_metric('tool:add', count=len(results), method_name='tool_add')
         return results
 
     @remote_api_endpoint('tool/data')
     @timed
     @db_transaction(statement_timeout=500)
     def tool_get(self, tool, db=None, cur=None):
         """Retrieve tool information.
 
         Args:
             tool (dict): Tool information we want to retrieve from storage.
               The dicts have the same keys as those used in :func:`tool_add`.
 
         Returns:
             dict: The full tool information if it exists (``id`` included),
             None otherwise.
 
         """
         tool_conf = tool['configuration']
         if isinstance(tool_conf, dict):
             tool_conf = json.dumps(tool_conf)
 
         idx = db.tool_get(tool['name'],
                           tool['version'],
                           tool_conf)
         if not idx:
             return None
         return dict(zip(db.tool_cols, idx))
 
     @remote_api_endpoint('provider/add')
     @timed
     @db_transaction()
     def metadata_provider_add(self, provider_name, provider_type, provider_url,
                               metadata, db=None, cur=None):
         """Add a metadata provider.
 
         Args:
             provider_name (str): Its name
             provider_type (str): Its type (eg. `'deposit-client'`)
             provider_url (str): Its URL
             metadata: JSON-encodable object
 
         Returns:
             int: an identifier of the provider
         """
         result = db.metadata_provider_add(provider_name, provider_type,
                                           provider_url, metadata, cur)
         send_metric(
             'metadata_provider:add', count=1, method_name='metadata_provider')
         return result
 
     @remote_api_endpoint('provider/get')
     @timed
     @db_transaction()
     def metadata_provider_get(self, provider_id, db=None, cur=None):
         """Get a metadata provider
 
         Args:
             provider_id: Its identifier, as given by `metadata_provider_add`.
 
         Returns:
             dict: same as `metadata_provider_add`;
                   or None if it does not exist.
         """
         result = db.metadata_provider_get(provider_id)
         if not result:
             return None
         return dict(zip(db.metadata_provider_cols, result))
 
     @remote_api_endpoint('provider/getby')
     @timed
     @db_transaction()
     def metadata_provider_get_by(self, provider, db=None, cur=None):
         """Get a metadata provider
 
         Args:
             provider (dict): A dictionary with keys:
                 * provider_name: Its name
                 * provider_url: Its URL
 
         Returns:
             dict: same as `metadata_provider_add`;
                   or None if it does not exist.
         """
         result = db.metadata_provider_get_by(provider['provider_name'],
                                              provider['provider_url'])
         if not result:
             return None
         return dict(zip(db.metadata_provider_cols, result))
 
     @remote_api_endpoint('algos/diff_directories')
     @timed
     def diff_directories(self, from_dir, to_dir, track_renaming=False):
         """Compute the list of file changes introduced between two arbitrary
         directories (insertion / deletion / modification / renaming of files).
 
         Args:
             from_dir (bytes): identifier of the directory to compare from
             to_dir (bytes): identifier of the directory to compare to
             track_renaming (bool): whether or not to track files renaming
 
         Returns:
             A list of dict describing the introduced file changes
             (see :func:`swh.storage.algos.diff.diff_directories`
             for more details).
         """
         return diff.diff_directories(self, from_dir, to_dir, track_renaming)
 
     @remote_api_endpoint('algos/diff_revisions')
     @timed
     def diff_revisions(self, from_rev, to_rev, track_renaming=False):
         """Compute the list of file changes introduced between two arbitrary
         revisions (insertion / deletion / modification / renaming of files).
 
         Args:
             from_rev (bytes): identifier of the revision to compare from
             to_rev (bytes): identifier of the revision to compare to
             track_renaming (bool): whether or not to track files renaming
 
         Returns:
             A list of dict describing the introduced file changes
             (see :func:`swh.storage.algos.diff.diff_directories`
             for more details).
         """
         return diff.diff_revisions(self, from_rev, to_rev, track_renaming)
 
     @remote_api_endpoint('algos/diff_revision')
     @timed
     def diff_revision(self, revision, track_renaming=False):
         """Compute the list of file changes introduced by a specific revision
         (insertion / deletion / modification / renaming of files) by comparing
         it against its first parent.
 
         Args:
             revision (bytes): identifier of the revision from which to
                 compute the list of files changes
             track_renaming (bool): whether or not to track files renaming
 
         Returns:
             A list of dict describing the introduced file changes
             (see :func:`swh.storage.algos.diff.diff_directories`
             for more details).
         """
         return diff.diff_revision(self, revision, track_renaming)
diff --git a/swh/storage/tests/test_storage.py b/swh/storage/tests/test_storage.py
index 0e03f080..7cac9b5a 100644
--- a/swh/storage/tests/test_storage.py
+++ b/swh/storage/tests/test_storage.py
@@ -1,3540 +1,3566 @@
 # Copyright (C) 2015-2019  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import copy
 from contextlib import contextmanager
 import datetime
 import itertools
 import queue
 import random
 import threading
 
 from collections import defaultdict
 from datetime import timedelta
 from unittest.mock import Mock
 
 import psycopg2
 import pytest
 
 from hypothesis import given, strategies, settings, HealthCheck
 
 from typing import ClassVar, Optional
 
 from swh.model import from_disk, identifiers
 from swh.model.hashutil import hash_to_bytes
 from swh.model.hypothesis_strategies import objects
 from swh.storage import HashCollision
 from swh.storage.converters import origin_url_to_sha1 as sha1
 
 from .storage_data import data
 
 
 @contextmanager
 def db_transaction(storage):
     with storage.db() as db:
         with db.transaction() as cur:
             yield db, cur
 
 
 def normalize_entity(entity):
     entity = copy.deepcopy(entity)
     for key in ('date', 'committer_date'):
         if key in entity:
             entity[key] = identifiers.normalize_timestamp(entity[key])
     return entity
 
 
 def transform_entries(dir_, *, prefix=b''):
     for ent in dir_['entries']:
         yield {
             'dir_id': dir_['id'],
             'type': ent['type'],
             'target': ent['target'],
             'name': prefix + ent['name'],
             'perms': ent['perms'],
             'status': None,
             'sha1': None,
             'sha1_git': None,
             'sha256': None,
             'length': None,
         }
 
 
 def cmpdir(directory):
     return (directory['type'], directory['dir_id'])
 
 
 def short_revision(revision):
     return [revision['id'], revision['parents']]
 
 
 class TestStorage:
     """Main class for Storage testing.
 
     This class is used as-is to test local storage (see TestLocalStorage
     below) and remote storage (see TestRemoteStorage in
     test_remote_storage.py.
 
     We need to have the two classes inherit from this base class
     separately to avoid nosetests running the tests from the base
     class twice.
     """
     maxDiff = None  # type: ClassVar[Optional[int]]
 
     def test_check_config(self, swh_storage):
         assert swh_storage.check_config(check_write=True)
         assert swh_storage.check_config(check_write=False)
 
     def test_content_add(self, swh_storage):
         cont = data.cont
 
         insertion_start_time = datetime.datetime.now(tz=datetime.timezone.utc)
         actual_result = swh_storage.content_add([cont])
         insertion_end_time = datetime.datetime.now(tz=datetime.timezone.utc)
 
         assert actual_result == {
             'content:add': 1,
             'content:add:bytes': cont['length'],
             'skipped_content:add': 0
         }
 
         assert list(swh_storage.content_get([cont['sha1']])) == \
             [{'sha1': cont['sha1'], 'data': cont['data']}]
 
         expected_cont = data.cont
         del expected_cont['data']
         journal_objects = list(swh_storage.journal_writer.objects)
         for (obj_type, obj) in journal_objects:
             assert insertion_start_time <= obj['ctime']
             assert obj['ctime'] <= insertion_end_time
             del obj['ctime']
         assert journal_objects == [('content', expected_cont)]
 
     def test_content_add_validation(self, swh_storage):
         cont = data.cont
 
         with pytest.raises(ValueError, match='status'):
             swh_storage.content_add([{**cont, 'status': 'foobar'}])
 
         with pytest.raises(ValueError, match="(?i)length"):
             swh_storage.content_add([{**cont, 'length': -2}])
 
         with pytest.raises((ValueError, psycopg2.IntegrityError),
                            match='reason') as cm:
             swh_storage.content_add([{**cont, 'status': 'absent'}])
 
         if type(cm.value) == psycopg2.IntegrityError:
             assert cm.exception.pgcode == \
                 psycopg2.errorcodes.NOT_NULL_VIOLATION
 
         with pytest.raises(
                 ValueError,
                 match="^Must not provide a reason if content is not absent.$"):
             swh_storage.content_add([{**cont, 'reason': 'foobar'}])
 
     def test_content_get_missing(self, swh_storage):
         cont = data.cont
 
         swh_storage.content_add([cont])
 
         # Query a single missing content
         results = list(swh_storage.content_get(
             [data.cont2['sha1']]))
         assert results == [None]
 
         # Check content_get does not abort after finding a missing content
         results = list(swh_storage.content_get(
             [data.cont['sha1'], data.cont2['sha1']]))
         assert results == [{'sha1': cont['sha1'], 'data': cont['data']}, None]
 
         # Check content_get does not discard found countent when it finds
         # a missing content.
         results = list(swh_storage.content_get(
             [data.cont2['sha1'], data.cont['sha1']]))
         assert results == [None, {'sha1': cont['sha1'], 'data': cont['data']}]
 
     def test_content_add_same_input(self, swh_storage):
         cont = data.cont
 
         actual_result = swh_storage.content_add([cont, cont])
         assert actual_result == {
             'content:add': 1,
             'content:add:bytes': cont['length'],
             'skipped_content:add': 0
             }
 
     def test_content_add_different_input(self, swh_storage):
         cont = data.cont
         cont2 = data.cont2
 
         actual_result = swh_storage.content_add([cont, cont2])
         assert actual_result == {
             'content:add': 2,
             'content:add:bytes': cont['length'] + cont2['length'],
             'skipped_content:add': 0
             }
 
     def test_content_add_twice(self, swh_storage):
         actual_result = swh_storage.content_add([data.cont])
         assert actual_result == {
             'content:add': 1,
             'content:add:bytes': data.cont['length'],
             'skipped_content:add': 0
             }
         assert len(swh_storage.journal_writer.objects) == 1
 
         actual_result = swh_storage.content_add([data.cont, data.cont2])
         assert actual_result == {
             'content:add': 1,
             'content:add:bytes': data.cont2['length'],
             'skipped_content:add': 0
             }
         assert len(swh_storage.journal_writer.objects) == 2
 
         assert len(swh_storage.content_find(data.cont)) == 1
         assert len(swh_storage.content_find(data.cont2)) == 1
 
     def test_content_add_collision(self, swh_storage):
         cont1 = data.cont
 
         # create (corrupted) content with same sha1{,_git} but != sha256
         cont1b = cont1.copy()
         sha256_array = bytearray(cont1b['sha256'])
         sha256_array[0] += 1
         cont1b['sha256'] = bytes(sha256_array)
 
         with pytest.raises(HashCollision) as cm:
             swh_storage.content_add([cont1, cont1b])
 
         assert cm.value.args[0] in ['sha1', 'sha1_git', 'blake2s256']
 
     def test_content_add_metadata(self, swh_storage):
         cont = data.cont
         del cont['data']
         cont['ctime'] = datetime.datetime.now()
 
         actual_result = swh_storage.content_add_metadata([cont])
         assert actual_result == {
             'content:add': 1,
             'skipped_content:add': 0
             }
 
         expected_cont = cont.copy()
         del expected_cont['ctime']
         assert list(swh_storage.content_get_metadata([cont['sha1']])) == \
             [expected_cont]
 
         assert list(swh_storage.journal_writer.objects) == [('content', cont)]
 
     def test_content_add_metadata_same_input(self, swh_storage):
         cont = data.cont
         del cont['data']
         cont['ctime'] = datetime.datetime.now()
 
         actual_result = swh_storage.content_add_metadata([cont, cont])
         assert actual_result == {
             'content:add': 1,
             'skipped_content:add': 0
             }
 
     def test_content_add_metadata_different_input(self, swh_storage):
         cont = data.cont
         del cont['data']
         cont['ctime'] = datetime.datetime.now()
         cont2 = data.cont2
         del cont2['data']
         cont2['ctime'] = datetime.datetime.now()
 
         actual_result = swh_storage.content_add_metadata([cont, cont2])
         assert actual_result == {
             'content:add': 2,
             'skipped_content:add': 0
             }
 
     def test_content_add_metadata_collision(self, swh_storage):
         cont1 = data.cont
         del cont1['data']
         cont1['ctime'] = datetime.datetime.now()
 
         # create (corrupted) content with same sha1{,_git} but != sha256
         cont1b = cont1.copy()
         sha256_array = bytearray(cont1b['sha256'])
         sha256_array[0] += 1
         cont1b['sha256'] = bytes(sha256_array)
 
         with pytest.raises(HashCollision) as cm:
             swh_storage.content_add_metadata([cont1, cont1b])
 
         assert cm.value.args[0] in ['sha1', 'sha1_git', 'blake2s256']
 
     def test_skipped_content_add(self, swh_storage):
         cont = data.skipped_cont
         cont2 = data.skipped_cont2
         cont2['blake2s256'] = None
 
         missing = list(swh_storage.skipped_content_missing([cont, cont2]))
 
         assert len(missing) == 2
 
         actual_result = swh_storage.content_add([cont, cont, cont2])
 
         assert actual_result == {
             'content:add': 0,
             'content:add:bytes': 0,
             'skipped_content:add': 2,
             }
 
         missing = list(swh_storage.skipped_content_missing([cont, cont2]))
 
         assert missing == []
 
     @pytest.mark.property_based
     @settings(deadline=None)  # this test is very slow
     @given(strategies.sets(
         elements=strategies.sampled_from(
             ['sha256', 'sha1_git', 'blake2s256']),
         min_size=0))
     def test_content_missing(self, swh_storage, algos):
         algos |= {'sha1'}
         cont2 = data.cont2
         missing_cont = data.missing_cont
         swh_storage.content_add([cont2])
         test_contents = [cont2]
         missing_per_hash = defaultdict(list)
         for i in range(256):
             test_content = missing_cont.copy()
             for hash in algos:
                 test_content[hash] = bytes([i]) + test_content[hash][1:]
                 missing_per_hash[hash].append(test_content[hash])
             test_contents.append(test_content)
 
         assert set(swh_storage.content_missing(test_contents)) == \
             set(missing_per_hash['sha1'])
 
         for hash in algos:
             assert set(swh_storage.content_missing(
                 test_contents, key_hash=hash)) == set(missing_per_hash[hash])
 
     @pytest.mark.property_based
     @given(strategies.sets(
         elements=strategies.sampled_from(
             ['sha256', 'sha1_git', 'blake2s256']),
         min_size=0))
     def test_content_missing_unknown_algo(self, swh_storage, algos):
         algos |= {'sha1'}
         cont2 = data.cont2
         missing_cont = data.missing_cont
         swh_storage.content_add([cont2])
         test_contents = [cont2]
         missing_per_hash = defaultdict(list)
         for i in range(16):
             test_content = missing_cont.copy()
             for hash in algos:
                 test_content[hash] = bytes([i]) + test_content[hash][1:]
                 missing_per_hash[hash].append(test_content[hash])
             test_content['nonexisting_algo'] = b'\x00'
             test_contents.append(test_content)
 
         assert set(
             swh_storage.content_missing(test_contents)) == set(
             missing_per_hash['sha1'])
 
         for hash in algos:
             assert set(swh_storage.content_missing(
                 test_contents, key_hash=hash)) == set(
                 missing_per_hash[hash])
 
     def test_content_missing_per_sha1(self, swh_storage):
         # given
         cont2 = data.cont2
         missing_cont = data.missing_cont
         swh_storage.content_add([cont2])
         # when
         gen = swh_storage.content_missing_per_sha1([cont2['sha1'],
                                                     missing_cont['sha1']])
         # then
         assert list(gen) == [missing_cont['sha1']]
 
     def test_content_get_metadata(self, swh_storage):
         cont1 = data.cont
         cont2 = data.cont2
 
         swh_storage.content_add([cont1, cont2])
 
         actual_md = list(swh_storage.content_get_metadata(
             [cont1['sha1'], cont2['sha1']]))
 
         # we only retrieve the metadata
         cont1.pop('data')
         cont2.pop('data')
 
         assert actual_md in ([cont1, cont2], [cont2, cont1])
 
     def test_content_get_metadata_missing_sha1(self, swh_storage):
         cont1 = data.cont
         cont2 = data.cont2
         missing_cont = data.missing_cont
 
         swh_storage.content_add([cont1, cont2])
 
         gen = swh_storage.content_get_metadata([missing_cont['sha1']])
 
         # All the metadata keys are None
         missing_cont.pop('data')
         for key in missing_cont:
             if key != 'sha1':
                 missing_cont[key] = None
 
         assert list(gen) == [missing_cont]
 
     def test_content_get_random(self, swh_storage):
         swh_storage.content_add([data.cont, data.cont2, data.cont3])
 
         assert swh_storage.content_get_random() in {
             data.cont['sha1_git'], data.cont2['sha1_git'],
             data.cont3['sha1_git']}
 
     def test_directory_add(self, swh_storage):
         init_missing = list(swh_storage.directory_missing([data.dir['id']]))
         assert [data.dir['id']] == init_missing
 
         actual_result = swh_storage.directory_add([data.dir])
         assert actual_result == {'directory:add': 1}
 
         assert list(swh_storage.journal_writer.objects) == \
             [('directory', data.dir)]
 
         actual_data = list(swh_storage.directory_ls(data.dir['id']))
         expected_data = list(transform_entries(data.dir))
 
         assert sorted(expected_data, key=cmpdir) \
             == sorted(actual_data, key=cmpdir)
 
         after_missing = list(swh_storage.directory_missing([data.dir['id']]))
         assert after_missing == []
 
     def test_directory_add_validation(self, swh_storage):
         dir_ = copy.deepcopy(data.dir)
         dir_['entries'][0]['type'] = 'foobar'
 
         with pytest.raises(ValueError, match='type.*foobar'):
             swh_storage.directory_add([dir_])
 
         dir_ = copy.deepcopy(data.dir)
         del dir_['entries'][0]['target']
 
         with pytest.raises((TypeError, psycopg2.IntegrityError),
                            match='target') as cm:
             swh_storage.directory_add([dir_])
 
         if type(cm.value) == psycopg2.IntegrityError:
             assert cm.value.pgcode == psycopg2.errorcodes.NOT_NULL_VIOLATION
 
     def test_directory_add_twice(self, swh_storage):
         actual_result = swh_storage.directory_add([data.dir])
         assert actual_result == {'directory:add': 1}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('directory', data.dir)]
 
         actual_result = swh_storage.directory_add([data.dir])
         assert actual_result == {'directory:add': 0}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('directory', data.dir)]
 
     def test_directory_get_recursive(self, swh_storage):
         init_missing = list(swh_storage.directory_missing([data.dir['id']]))
         assert init_missing == [data.dir['id']]
 
         actual_result = swh_storage.directory_add(
             [data.dir, data.dir2, data.dir3])
         assert actual_result == {'directory:add': 3}
 
         assert list(swh_storage.journal_writer.objects) == [
             ('directory', data.dir),
             ('directory', data.dir2),
             ('directory', data.dir3)]
 
         # List directory containing a file and an unknown subdirectory
         actual_data = list(swh_storage.directory_ls(
             data.dir['id'], recursive=True))
         expected_data = list(transform_entries(data.dir))
         assert sorted(expected_data, key=cmpdir) \
             == sorted(actual_data, key=cmpdir)
 
         # List directory containing a file and an unknown subdirectory
         actual_data = list(swh_storage.directory_ls(
             data.dir2['id'], recursive=True))
         expected_data = list(transform_entries(data.dir2))
         assert sorted(expected_data, key=cmpdir) \
             == sorted(actual_data, key=cmpdir)
 
         # List directory containing a known subdirectory, entries should
         # be both those of the directory and of the subdir
         actual_data = list(swh_storage.directory_ls(
             data.dir3['id'], recursive=True))
         expected_data = list(itertools.chain(
             transform_entries(data.dir3),
             transform_entries(data.dir, prefix=b'subdir/')))
         assert sorted(expected_data, key=cmpdir) \
             == sorted(actual_data, key=cmpdir)
 
     def test_directory_get_non_recursive(self, swh_storage):
         init_missing = list(swh_storage.directory_missing([data.dir['id']]))
         assert init_missing == [data.dir['id']]
 
         actual_result = swh_storage.directory_add(
             [data.dir, data.dir2, data.dir3])
         assert actual_result == {'directory:add': 3}
 
         assert list(swh_storage.journal_writer.objects) == [
             ('directory', data.dir),
             ('directory', data.dir2),
             ('directory', data.dir3)]
 
         # List directory containing a file and an unknown subdirectory
         actual_data = list(swh_storage.directory_ls(data.dir['id']))
         expected_data = list(transform_entries(data.dir))
         assert sorted(expected_data, key=cmpdir) \
             == sorted(actual_data, key=cmpdir)
 
         # List directory contaiining a single file
         actual_data = list(swh_storage.directory_ls(data.dir2['id']))
         expected_data = list(transform_entries(data.dir2))
         assert sorted(expected_data, key=cmpdir) \
             == sorted(actual_data, key=cmpdir)
 
         # List directory containing a known subdirectory, entries should
         # only be those of the parent directory, not of the subdir
         actual_data = list(swh_storage.directory_ls(data.dir3['id']))
         expected_data = list(transform_entries(data.dir3))
         assert sorted(expected_data, key=cmpdir) \
             == sorted(actual_data, key=cmpdir)
 
     def test_directory_entry_get_by_path(self, swh_storage):
         # given
         init_missing = list(swh_storage.directory_missing([data.dir3['id']]))
         assert [data.dir3['id']] == init_missing
 
         actual_result = swh_storage.directory_add([data.dir3, data.dir4])
         assert actual_result == {'directory:add': 2}
 
         expected_entries = [
             {
                 'dir_id': data.dir3['id'],
                 'name': b'foo',
                 'type': 'file',
                 'target': data.cont['sha1_git'],
                 'sha1': None,
                 'sha1_git': None,
                 'sha256': None,
                 'status': None,
                 'perms': from_disk.DentryPerms.content,
                 'length': None,
             },
             {
                 'dir_id': data.dir3['id'],
                 'name': b'subdir',
                 'type': 'dir',
                 'target': data.dir['id'],
                 'sha1': None,
                 'sha1_git': None,
                 'sha256': None,
                 'status': None,
                 'perms': from_disk.DentryPerms.directory,
                 'length': None,
             },
             {
                 'dir_id': data.dir3['id'],
                 'name': b'hello',
                 'type': 'file',
                 'target': b'12345678901234567890',
                 'sha1': None,
                 'sha1_git': None,
                 'sha256': None,
                 'status': None,
                 'perms': from_disk.DentryPerms.content,
                 'length': None,
             },
         ]
 
         # when (all must be found here)
         for entry, expected_entry in zip(
                 data.dir3['entries'], expected_entries):
             actual_entry = swh_storage.directory_entry_get_by_path(
                 data.dir3['id'],
                 [entry['name']])
             assert actual_entry == expected_entry
 
         # same, but deeper
         for entry, expected_entry in zip(
                 data.dir3['entries'], expected_entries):
             actual_entry = swh_storage.directory_entry_get_by_path(
                 data.dir4['id'],
                 [b'subdir1', entry['name']])
             expected_entry = expected_entry.copy()
             expected_entry['name'] = b'subdir1/' + expected_entry['name']
             assert actual_entry == expected_entry
 
         # when (nothing should be found here since data.dir is not persisted.)
         for entry in data.dir['entries']:
             actual_entry = swh_storage.directory_entry_get_by_path(
                 data.dir['id'],
                 [entry['name']])
             assert actual_entry is None
 
     def test_directory_get_random(self, swh_storage):
         swh_storage.directory_add([data.dir, data.dir2, data.dir3])
 
         assert swh_storage.directory_get_random() in \
             {data.dir['id'], data.dir2['id'], data.dir3['id']}
 
     def test_revision_add(self, swh_storage):
         init_missing = swh_storage.revision_missing([data.revision['id']])
         assert list(init_missing) == [data.revision['id']]
 
         actual_result = swh_storage.revision_add([data.revision])
         assert actual_result == {'revision:add': 1}
 
         end_missing = swh_storage.revision_missing([data.revision['id']])
         assert list(end_missing) == []
 
         assert list(swh_storage.journal_writer.objects) \
             == [('revision', data.revision)]
 
         # already there so nothing added
         actual_result = swh_storage.revision_add([data.revision])
         assert actual_result == {'revision:add': 0}
 
     def test_revision_add_validation(self, swh_storage):
         rev = copy.deepcopy(data.revision)
         rev['date']['offset'] = 2**16
 
         with pytest.raises((ValueError, psycopg2.DataError),
                            match='offset') as cm:
             swh_storage.revision_add([rev])
 
         if type(cm.value) == psycopg2.DataError:
             assert cm.value.pgcode \
                 == psycopg2.errorcodes.NUMERIC_VALUE_OUT_OF_RANGE
 
         rev = copy.deepcopy(data.revision)
         rev['committer_date']['offset'] = 2**16
 
         with pytest.raises((ValueError, psycopg2.DataError),
                            match='offset') as cm:
             swh_storage.revision_add([rev])
 
         if type(cm.value) == psycopg2.DataError:
             assert cm.value.pgcode \
                 == psycopg2.errorcodes.NUMERIC_VALUE_OUT_OF_RANGE
 
         rev = copy.deepcopy(data.revision)
         rev['type'] = 'foobar'
 
         with pytest.raises((ValueError, psycopg2.DataError),
                            match='(?i)type') as cm:
             swh_storage.revision_add([rev])
 
         if type(cm.value) == psycopg2.DataError:
             assert cm.value.pgcode == \
                 psycopg2.errorcodes.INVALID_TEXT_REPRESENTATION
 
     def test_revision_add_twice(self, swh_storage):
         actual_result = swh_storage.revision_add([data.revision])
         assert actual_result == {'revision:add': 1}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('revision', data.revision)]
 
         actual_result = swh_storage.revision_add(
             [data.revision, data.revision2])
         assert actual_result == {'revision:add': 1}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('revision', data.revision),
                 ('revision', data.revision2)]
 
     def test_revision_add_name_clash(self, swh_storage):
         revision1 = data.revision
         revision2 = data.revision2
 
         revision1['author'] = {
             'fullname': b'John Doe <john.doe@example.com>',
             'name': b'John Doe',
             'email': b'john.doe@example.com'
         }
         revision2['author'] = {
             'fullname': b'John Doe <john.doe@example.com>',
             'name': b'John Doe ',
             'email': b'john.doe@example.com '
         }
         actual_result = swh_storage.revision_add([revision1, revision2])
         assert actual_result == {'revision:add': 2}
 
     def test_revision_log(self, swh_storage):
         # given
         # data.revision4 -is-child-of-> data.revision3
         swh_storage.revision_add([data.revision3,
                                   data.revision4])
 
         # when
         actual_results = list(swh_storage.revision_log(
             [data.revision4['id']]))
 
         # hack: ids generated
         for actual_result in actual_results:
             if 'id' in actual_result['author']:
                 del actual_result['author']['id']
             if 'id' in actual_result['committer']:
                 del actual_result['committer']['id']
 
         assert len(actual_results) == 2  # rev4 -child-> rev3
         assert actual_results[0] == normalize_entity(data.revision4)
         assert actual_results[1] == normalize_entity(data.revision3)
 
         assert list(swh_storage.journal_writer.objects) == [
             ('revision', data.revision3),
             ('revision', data.revision4)]
 
     def test_revision_log_with_limit(self, swh_storage):
         # given
         # data.revision4 -is-child-of-> data.revision3
         swh_storage.revision_add([data.revision3,
                                   data.revision4])
         actual_results = list(swh_storage.revision_log(
             [data.revision4['id']], 1))
 
         # hack: ids generated
         for actual_result in actual_results:
             if 'id' in actual_result['author']:
                 del actual_result['author']['id']
             if 'id' in actual_result['committer']:
                 del actual_result['committer']['id']
 
         assert len(actual_results) == 1
         assert actual_results[0] == data.revision4
 
     def test_revision_log_unknown_revision(self, swh_storage):
         rev_log = list(swh_storage.revision_log([data.revision['id']]))
         assert rev_log == []
 
     def test_revision_shortlog(self, swh_storage):
         # given
         # data.revision4 -is-child-of-> data.revision3
         swh_storage.revision_add([data.revision3,
                                   data.revision4])
 
         # when
         actual_results = list(swh_storage.revision_shortlog(
             [data.revision4['id']]))
 
         assert len(actual_results) == 2  # rev4 -child-> rev3
         assert list(actual_results[0]) == short_revision(data.revision4)
         assert list(actual_results[1]) == short_revision(data.revision3)
 
     def test_revision_shortlog_with_limit(self, swh_storage):
         # given
         # data.revision4 -is-child-of-> data.revision3
         swh_storage.revision_add([data.revision3,
                                   data.revision4])
         actual_results = list(swh_storage.revision_shortlog(
             [data.revision4['id']], 1))
 
         assert len(actual_results) == 1
         assert list(actual_results[0]) == short_revision(data.revision4)
 
     def test_revision_get(self, swh_storage):
         swh_storage.revision_add([data.revision])
 
         actual_revisions = list(swh_storage.revision_get(
             [data.revision['id'], data.revision2['id']]))
 
         # when
         if 'id' in actual_revisions[0]['author']:
             del actual_revisions[0]['author']['id']  # hack: ids are generated
         if 'id' in actual_revisions[0]['committer']:
             del actual_revisions[0]['committer']['id']
 
         assert len(actual_revisions) == 2
         assert actual_revisions[0] == normalize_entity(data.revision)
         assert actual_revisions[1] is None
 
     def test_revision_get_no_parents(self, swh_storage):
         swh_storage.revision_add([data.revision3])
 
         get = list(swh_storage.revision_get([data.revision3['id']]))
 
         assert len(get) == 1
         assert get[0]['parents'] == []  # no parents on this one
 
     def test_revision_get_random(self, swh_storage):
         swh_storage.revision_add(
             [data.revision, data.revision2, data.revision3])
 
         assert swh_storage.revision_get_random() in \
             {data.revision['id'], data.revision2['id'], data.revision3['id']}
 
     def test_release_add(self, swh_storage):
         init_missing = swh_storage.release_missing([data.release['id'],
                                                     data.release2['id']])
         assert [data.release['id'], data.release2['id']] == list(init_missing)
 
         actual_result = swh_storage.release_add([data.release, data.release2])
         assert actual_result == {'release:add': 2}
 
         end_missing = swh_storage.release_missing([data.release['id'],
                                                    data.release2['id']])
         assert list(end_missing) == []
 
         assert list(swh_storage.journal_writer.objects) == [
             ('release', data.release),
             ('release', data.release2)]
 
         # already present so nothing added
         actual_result = swh_storage.release_add([data.release, data.release2])
         assert actual_result == {'release:add': 0}
 
     def test_release_add_no_author_date(self, swh_storage):
         release = data.release
 
         release['author'] = None
         release['date'] = None
 
         actual_result = swh_storage.release_add([release])
         assert actual_result == {'release:add': 1}
 
         end_missing = swh_storage.release_missing([data.release['id']])
         assert list(end_missing) == []
 
         assert list(swh_storage.journal_writer.objects) \
             == [('release', release)]
 
     def test_release_add_validation(self, swh_storage):
         rel = copy.deepcopy(data.release)
         rel['date']['offset'] = 2**16
 
         with pytest.raises((ValueError, psycopg2.DataError),
                            match='offset') as cm:
             swh_storage.release_add([rel])
 
         if type(cm.value) == psycopg2.DataError:
             assert cm.value.pgcode \
                 == psycopg2.errorcodes.NUMERIC_VALUE_OUT_OF_RANGE
 
         rel = copy.deepcopy(data.release)
         rel['author'] = None
 
         with pytest.raises((ValueError, psycopg2.IntegrityError),
                            match='date') as cm:
             swh_storage.release_add([rel])
 
         if type(cm.value) == psycopg2.IntegrityError:
             assert cm.value.pgcode == psycopg2.errorcodes.CHECK_VIOLATION
 
     def test_release_add_twice(self, swh_storage):
         actual_result = swh_storage.release_add([data.release])
         assert actual_result == {'release:add': 1}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('release', data.release)]
 
         actual_result = swh_storage.release_add([data.release, data.release2])
         assert actual_result == {'release:add': 1}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('release', data.release),
                 ('release', data.release2)]
 
     def test_release_add_name_clash(self, swh_storage):
         release1 = data.release.copy()
         release2 = data.release2.copy()
 
         release1['author'] = {
             'fullname': b'John Doe <john.doe@example.com>',
             'name': b'John Doe',
             'email': b'john.doe@example.com'
         }
         release2['author'] = {
             'fullname': b'John Doe <john.doe@example.com>',
             'name': b'John Doe ',
             'email': b'john.doe@example.com '
         }
         actual_result = swh_storage.release_add([release1, release2])
         assert actual_result == {'release:add': 2}
 
     def test_release_get(self, swh_storage):
         # given
         swh_storage.release_add([data.release, data.release2])
 
         # when
         actual_releases = list(swh_storage.release_get([data.release['id'],
                                                         data.release2['id']]))
 
         # then
         for actual_release in actual_releases:
             if 'id' in actual_release['author']:
                 del actual_release['author']['id']  # hack: ids are generated
 
         assert [
             normalize_entity(data.release), normalize_entity(data.release2)] \
             == [actual_releases[0], actual_releases[1]]
 
         unknown_releases = \
             list(swh_storage.release_get([data.release3['id']]))
 
         assert unknown_releases[0] is None
 
     def test_release_get_random(self, swh_storage):
         swh_storage.release_add([data.release, data.release2, data.release3])
 
         assert swh_storage.release_get_random() in \
             {data.release['id'], data.release2['id'], data.release3['id']}
 
     def test_origin_add_one(self, swh_storage):
         origin0 = swh_storage.origin_get(data.origin)
         assert origin0 is None
 
         id = swh_storage.origin_add_one(data.origin)
 
         actual_origin = swh_storage.origin_get({'url': data.origin['url']})
         assert actual_origin['url'] == data.origin['url']
 
         id2 = swh_storage.origin_add_one(data.origin)
 
         assert id == id2
 
     def test_origin_add(self, swh_storage):
         origin0 = swh_storage.origin_get([data.origin])[0]
         assert origin0 is None
 
         origin1, origin2 = swh_storage.origin_add([data.origin, data.origin2])
 
         actual_origin = swh_storage.origin_get([{
             'url': data.origin['url'],
         }])[0]
         assert actual_origin['url'] == origin1['url']
 
         actual_origin2 = swh_storage.origin_get([{
             'url': data.origin2['url'],
         }])[0]
         assert actual_origin2['url'] == origin2['url']
 
         if 'id' in actual_origin:
             del actual_origin['id']
             del actual_origin2['id']
 
         assert list(swh_storage.journal_writer.objects) \
             == [('origin', actual_origin),
                 ('origin', actual_origin2)]
 
     def test_origin_add_twice(self, swh_storage):
         add1 = swh_storage.origin_add([data.origin, data.origin2])
         assert list(swh_storage.journal_writer.objects) \
             == [('origin', data.origin),
                 ('origin', data.origin2)]
 
         add2 = swh_storage.origin_add([data.origin, data.origin2])
         assert list(swh_storage.journal_writer.objects) \
             == [('origin', data.origin),
                 ('origin', data.origin2)]
 
         assert add1 == add2
 
     def test_origin_add_validation(self, swh_storage):
         with pytest.raises((TypeError, KeyError), match='url'):
             swh_storage.origin_add([{'type': 'git'}])
 
     def test_origin_get_legacy(self, swh_storage):
         assert swh_storage.origin_get(data.origin) is None
         swh_storage.origin_add_one(data.origin)
 
         actual_origin0 = swh_storage.origin_get(
             {'url': data.origin['url']})
         assert actual_origin0['url'] == data.origin['url']
 
     def test_origin_get(self, swh_storage):
         assert swh_storage.origin_get(data.origin) is None
         swh_storage.origin_add_one(data.origin)
 
         actual_origin0 = swh_storage.origin_get(
             [{'url': data.origin['url']}])
         assert len(actual_origin0) == 1
         assert actual_origin0[0]['url'] == data.origin['url']
 
     def _generate_random_visits(self, nb_visits=100, start=0, end=7):
         """Generate random visits within the last 2 months (to avoid
         computations)
 
         """
         visits = []
         today = datetime.datetime.now(tz=datetime.timezone.utc)
         for weeks in range(nb_visits, 0, -1):
             hours = random.randint(0, 24)
             minutes = random.randint(0, 60)
             seconds = random.randint(0, 60)
             days = random.randint(0, 28)
             weeks = random.randint(start, end)
             date_visit = today - timedelta(
                 weeks=weeks, hours=hours, minutes=minutes,
                 seconds=seconds, days=days)
             visits.append(date_visit)
         return visits
 
     def test_origin_visit_get_random(self, swh_storage):
         swh_storage.origin_add(data.origins)
         # Add some random visits within the selection range
         visits = self._generate_random_visits()
         visit_type = 'git'
 
         # Add visits to those origins
         for origin in data.origins:
             for date_visit in visits:
                 visit = swh_storage.origin_visit_add(
                     origin['url'], date=date_visit, type=visit_type)
                 swh_storage.origin_visit_update(
                     origin['url'], visit_id=visit['visit'], status='full')
 
         swh_storage.refresh_stat_counters()
 
         stats = swh_storage.stat_counters()
         assert stats['origin'] == len(data.origins)
         assert stats['origin_visit'] == len(data.origins) * len(visits)
 
         random_origin_visit = swh_storage.origin_visit_get_random(visit_type)
         assert random_origin_visit
         assert random_origin_visit['origin'] is not None
         original_urls = [o['url'] for o in data.origins]
         assert random_origin_visit['origin'] in original_urls
 
     def test_origin_visit_get_random_nothing_found(self, swh_storage):
         swh_storage.origin_add(data.origins)
         visit_type = 'hg'
         # Add some visits outside of the random generation selection so nothing
         # will be found by the random selection
         visits = self._generate_random_visits(nb_visits=3, start=13, end=24)
         for origin in data.origins:
             for date_visit in visits:
                 visit = swh_storage.origin_visit_add(
                     origin['url'], date=date_visit, type=visit_type)
                 swh_storage.origin_visit_update(
                     origin['url'], visit_id=visit['visit'], status='full')
 
         random_origin_visit = swh_storage.origin_visit_get_random(visit_type)
         assert random_origin_visit == {}
 
     def test_origin_get_by_sha1(self, swh_storage):
         assert swh_storage.origin_get(data.origin) is None
         swh_storage.origin_add_one(data.origin)
 
         origins = list(swh_storage.origin_get_by_sha1([
             sha1(data.origin['url'])
         ]))
         assert len(origins) == 1
         assert origins[0]['url'] == data.origin['url']
 
     def test_origin_get_by_sha1_not_found(self, swh_storage):
         assert swh_storage.origin_get(data.origin) is None
         origins = list(swh_storage.origin_get_by_sha1([
             sha1(data.origin['url'])
         ]))
         assert len(origins) == 1
         assert origins[0] is None
 
     def test_origin_search_single_result(self, swh_storage):
         found_origins = list(swh_storage.origin_search(data.origin['url']))
         assert len(found_origins) == 0
 
         found_origins = list(swh_storage.origin_search(data.origin['url'],
                                                        regexp=True))
         assert len(found_origins) == 0
 
         swh_storage.origin_add_one(data.origin)
         origin_data = {
             'url': data.origin['url']}
         found_origins = list(swh_storage.origin_search(data.origin['url']))
         assert len(found_origins) == 1
         if 'id' in found_origins[0]:
             del found_origins[0]['id']
         assert found_origins[0] == origin_data
 
         found_origins = list(swh_storage.origin_search(
             '.' + data.origin['url'][1:-1] + '.', regexp=True))
         assert len(found_origins) == 1
         if 'id' in found_origins[0]:
             del found_origins[0]['id']
         assert found_origins[0] == origin_data
 
         swh_storage.origin_add_one(data.origin2)
         origin2_data = {'url': data.origin2['url']}
         found_origins = list(swh_storage.origin_search(data.origin2['url']))
         assert len(found_origins) == 1
         if 'id' in found_origins[0]:
             del found_origins[0]['id']
         assert found_origins[0] == origin2_data
 
         found_origins = list(swh_storage.origin_search(
             '.' + data.origin2['url'][1:-1] + '.', regexp=True))
         assert len(found_origins) == 1
         if 'id' in found_origins[0]:
             del found_origins[0]['id']
         assert found_origins[0] == origin2_data
 
     def test_origin_search_no_regexp(self, swh_storage):
         swh_storage.origin_add_one(data.origin)
         swh_storage.origin_add_one(data.origin2)
 
         origin = swh_storage.origin_get({'url': data.origin['url']})
         origin2 = swh_storage.origin_get({'url': data.origin2['url']})
 
         # no pagination
         found_origins = list(swh_storage.origin_search('/'))
         assert len(found_origins) == 2
 
         # offset=0
         found_origins0 = list(swh_storage.origin_search('/', offset=0, limit=1)) # noqa
         assert len(found_origins0) == 1
         assert found_origins0[0] in [origin, origin2]
 
         # offset=1
         found_origins1 = list(swh_storage.origin_search('/', offset=1, limit=1)) # noqa
         assert len(found_origins1) == 1
         assert found_origins1[0] in [origin, origin2]
 
         # check both origins were returned
         assert found_origins0 != found_origins1
 
     def test_origin_search_regexp_substring(self, swh_storage):
         swh_storage.origin_add_one(data.origin)
         swh_storage.origin_add_one(data.origin2)
 
         origin = swh_storage.origin_get({'url': data.origin['url']})
         origin2 = swh_storage.origin_get({'url': data.origin2['url']})
 
         # no pagination
         found_origins = list(swh_storage.origin_search('/', regexp=True))
         assert len(found_origins) == 2
 
         # offset=0
         found_origins0 = list(swh_storage.origin_search('/', offset=0, limit=1, regexp=True)) # noqa
         assert len(found_origins0) == 1
         assert found_origins0[0] in [origin, origin2]
 
         # offset=1
         found_origins1 = list(swh_storage.origin_search('/', offset=1, limit=1, regexp=True)) # noqa
         assert len(found_origins1) == 1
         assert found_origins1[0] in [origin, origin2]
 
         # check both origins were returned
         assert found_origins0 != found_origins1
 
     def test_origin_search_regexp_fullstring(self, swh_storage):
         swh_storage.origin_add_one(data.origin)
         swh_storage.origin_add_one(data.origin2)
 
         origin = swh_storage.origin_get({'url': data.origin['url']})
         origin2 = swh_storage.origin_get({'url': data.origin2['url']})
 
         # no pagination
         found_origins = list(swh_storage.origin_search('.*/.*', regexp=True))
         assert len(found_origins) == 2
 
         # offset=0
         found_origins0 = list(swh_storage.origin_search('.*/.*', offset=0, limit=1, regexp=True)) # noqa
         assert len(found_origins0) == 1
         assert found_origins0[0] in [origin, origin2]
 
         # offset=1
         found_origins1 = list(swh_storage.origin_search('.*/.*', offset=1, limit=1, regexp=True)) # noqa
         assert len(found_origins1) == 1
         assert found_origins1[0] in [origin, origin2]
 
         # check both origins were returned
         assert found_origins0 != found_origins1
 
     def test_origin_visit_add(self, swh_storage):
         # given
         swh_storage.origin_add_one(data.origin2)
 
         origin_url = data.origin2['url']
 
         # when
         date_visit = datetime.datetime.now(datetime.timezone.utc)
         origin_visit1 = swh_storage.origin_visit_add(
             origin_url,
             type=data.type_visit1,
             date=date_visit)
 
         actual_origin_visits = list(swh_storage.origin_visit_get(
             origin_url))
         assert {
                 'origin': origin_url,
                 'date': date_visit,
                 'visit': origin_visit1['visit'],
                 'type': data.type_visit1,
                 'status': 'ongoing',
                 'metadata': None,
                 'snapshot': None,
             } in actual_origin_visits
 
         origin_visit = {
             'origin': origin_url,
             'date': date_visit,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         objects = list(swh_storage.journal_writer.objects)
         assert ('origin', data.origin2) in objects
         assert ('origin_visit', origin_visit) in objects
 
     def test_origin_visit_get__unknown_origin(self, swh_storage):
         assert [] == list(swh_storage.origin_visit_get('foo'))
 
     def test_origin_visit_add_default_type(self, swh_storage):
         # given
         swh_storage.origin_add_one(data.origin2)
         origin_url = data.origin2['url']
 
         # when
         date_visit = datetime.datetime.now(datetime.timezone.utc)
         date_visit2 = date_visit + datetime.timedelta(minutes=1)
         origin_visit1 = swh_storage.origin_visit_add(
             origin_url,
             date=date_visit,
             type=data.type_visit1,
         )
         origin_visit2 = swh_storage.origin_visit_add(
             origin_url,
             date=date_visit2,
             type=data.type_visit2,
         )
 
         # then
         assert origin_visit1['origin'] == origin_url
         assert origin_visit1['visit'] is not None
 
         actual_origin_visits = list(swh_storage.origin_visit_get(
             origin_url))
         expected_visits = [
                 {
                     'origin': origin_url,
                     'date': date_visit,
                     'visit': origin_visit1['visit'],
                     'type': data.type_visit1,
                     'status': 'ongoing',
                     'metadata': None,
                     'snapshot': None,
                 },
                 {
                     'origin': origin_url,
                     'date': date_visit2,
                     'visit': origin_visit2['visit'],
                     'type': data.type_visit2,
                     'status': 'ongoing',
                     'metadata': None,
                     'snapshot': None,
                 },
             ]
         for visit in expected_visits:
             assert visit in actual_origin_visits
 
         objects = list(swh_storage.journal_writer.objects)
         assert ('origin', data.origin2) in objects
 
         for visit in expected_visits:
             assert ('origin_visit', visit) in objects
 
     def test_origin_visit_add_validation(self, swh_storage):
         origin_url = swh_storage.origin_add_one(data.origin2)
 
         with pytest.raises((TypeError, psycopg2.ProgrammingError)) as cm:
             swh_storage.origin_visit_add(origin_url, date=[b'foo'])
 
         if type(cm.value) == psycopg2.ProgrammingError:
             assert cm.value.pgcode \
                 == psycopg2.errorcodes.UNDEFINED_FUNCTION
 
     def test_origin_visit_update(self, swh_storage):
         # given
         swh_storage.origin_add_one(data.origin)
         origin_url = data.origin['url']
 
         date_visit = datetime.datetime.now(datetime.timezone.utc)
         origin_visit1 = swh_storage.origin_visit_add(
             origin_url,
             date=date_visit,
             type=data.type_visit1,
         )
 
         date_visit2 = date_visit + datetime.timedelta(minutes=1)
         origin_visit2 = swh_storage.origin_visit_add(
             origin_url,
             date=date_visit2,
             type=data.type_visit2
         )
 
         swh_storage.origin_add_one(data.origin2)
         origin_url2 = data.origin2['url']
         origin_visit3 = swh_storage.origin_visit_add(
             origin_url2,
             date=date_visit2,
             type=data.type_visit3
         )
 
         # when
         visit1_metadata = {
             'contents': 42,
             'directories': 22,
         }
         swh_storage.origin_visit_update(
             origin_url,
             origin_visit1['visit'], status='full',
             metadata=visit1_metadata)
         swh_storage.origin_visit_update(
             origin_url2,
             origin_visit3['visit'], status='partial')
 
         # then
         actual_origin_visits = list(swh_storage.origin_visit_get(
             origin_url))
         expected_visits = [{
             'origin': origin_url,
             'date': date_visit,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'full',
             'metadata': visit1_metadata,
             'snapshot': None,
         }, {
             'origin': origin_url,
             'date': date_visit2,
             'visit': origin_visit2['visit'],
             'type': data.type_visit2,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }]
         for visit in expected_visits:
             assert visit in actual_origin_visits
 
         actual_origin_visits_bis = list(swh_storage.origin_visit_get(
             origin_url,
             limit=1))
         assert actual_origin_visits_bis == [
             {
                 'origin': origin_url,
                 'date': date_visit,
                 'visit': origin_visit1['visit'],
                 'type': data.type_visit1,
                 'status': 'full',
                 'metadata': visit1_metadata,
                 'snapshot': None,
             }]
 
         actual_origin_visits_ter = list(swh_storage.origin_visit_get(
             origin_url,
             last_visit=origin_visit1['visit']))
         assert actual_origin_visits_ter == [
             {
                 'origin': origin_url,
                 'date': date_visit2,
                 'visit': origin_visit2['visit'],
                 'type': data.type_visit2,
                 'status': 'ongoing',
                 'metadata': None,
                 'snapshot': None,
             }]
 
         actual_origin_visits2 = list(swh_storage.origin_visit_get(
             origin_url2))
         assert actual_origin_visits2 == [
             {
                 'origin': origin_url2,
                 'date': date_visit2,
                 'visit': origin_visit3['visit'],
                 'type': data.type_visit3,
                 'status': 'partial',
                 'metadata': None,
                 'snapshot': None,
             }]
 
         data1 = {
             'origin': origin_url,
             'date': date_visit,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         data2 = {
             'origin': origin_url,
             'date': date_visit2,
             'visit': origin_visit2['visit'],
             'type': data.type_visit2,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         data3 = {
             'origin': origin_url2,
             'date': date_visit2,
             'visit': origin_visit3['visit'],
             'type': data.type_visit3,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         data4 = {
             'origin': origin_url,
             'date': date_visit,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'metadata': visit1_metadata,
             'status': 'full',
             'snapshot': None,
         }
         data5 = {
             'origin': origin_url2,
             'date': date_visit2,
             'visit': origin_visit3['visit'],
             'type': data.type_visit3,
             'status': 'partial',
             'metadata': None,
             'snapshot': None,
         }
         objects = list(swh_storage.journal_writer.objects)
         assert ('origin', data.origin) in objects
         assert ('origin', data.origin2) in objects
         assert ('origin_visit', data1) in objects
         assert ('origin_visit', data2) in objects
         assert ('origin_visit', data3) in objects
         assert ('origin_visit', data4) in objects
         assert ('origin_visit', data5) in objects
 
     def test_origin_visit_update_validation(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         visit = swh_storage.origin_visit_add(
             origin_url,
             date=data.date_visit2,
             type=data.type_visit2,
         )
 
         with pytest.raises((ValueError, psycopg2.DataError),
                            match='status') as cm:
             swh_storage.origin_visit_update(
                 origin_url, visit['visit'], status='foobar')
 
         if type(cm.value) == psycopg2.DataError:
             assert cm.value.pgcode == \
                 psycopg2.errorcodes.INVALID_TEXT_REPRESENTATION
 
     def test_origin_visit_find_by_date(self, swh_storage):
         # given
         swh_storage.origin_add_one(data.origin)
 
         swh_storage.origin_visit_add(
             data.origin['url'],
             date=data.date_visit2,
             type=data.type_visit1,
         )
 
         origin_visit2 = swh_storage.origin_visit_add(
             data.origin['url'],
             date=data.date_visit3,
             type=data.type_visit2,
         )
 
         origin_visit3 = swh_storage.origin_visit_add(
             data.origin['url'],
             date=data.date_visit2,
             type=data.type_visit3,
         )
 
         # Simple case
         visit = swh_storage.origin_visit_find_by_date(
             data.origin['url'], data.date_visit3)
         assert visit['visit'] == origin_visit2['visit']
 
         # There are two visits at the same date, the latest must be returned
         visit = swh_storage.origin_visit_find_by_date(
             data.origin['url'], data.date_visit2)
         assert visit['visit'] == origin_visit3['visit']
 
     def test_origin_visit_find_by_date__unknown_origin(self, swh_storage):
         swh_storage.origin_visit_find_by_date('foo', data.date_visit2)
 
     def test_origin_visit_update_missing_snapshot(self, swh_storage):
         # given
         swh_storage.origin_add_one(data.origin)
         origin_url = data.origin['url']
 
         origin_visit = swh_storage.origin_visit_add(
             origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
 
         # when
         swh_storage.origin_visit_update(
             origin_url,
             origin_visit['visit'],
             snapshot=data.snapshot['id'])
 
         # then
         actual_origin_visit = swh_storage.origin_visit_get_by(
             origin_url,
             origin_visit['visit'])
         assert actual_origin_visit['snapshot'] == data.snapshot['id']
 
         # when
         swh_storage.snapshot_add([data.snapshot])
         assert actual_origin_visit['snapshot'] == data.snapshot['id']
 
     def test_origin_visit_get_by(self, swh_storage):
         swh_storage.origin_add_one(data.origin)
         swh_storage.origin_add_one(data.origin2)
 
         origin_url = data.origin['url']
         origin2_url = data.origin2['url']
 
         origin_visit1 = swh_storage.origin_visit_add(
             origin_url,
             date=data.date_visit2,
             type=data.type_visit2,
         )
 
         swh_storage.snapshot_add([data.snapshot])
         swh_storage.origin_visit_update(
             origin_url,
             origin_visit1['visit'],
             snapshot=data.snapshot['id'])
 
         # Add some other {origin, visit} entries
         swh_storage.origin_visit_add(
             origin_url,
             date=data.date_visit3,
             type=data.type_visit3,
         )
         swh_storage.origin_visit_add(
             origin2_url,
             date=data.date_visit3,
             type=data.type_visit3,
         )
 
         # when
         visit1_metadata = {
             'contents': 42,
             'directories': 22,
         }
 
         swh_storage.origin_visit_update(
             origin_url,
             origin_visit1['visit'], status='full',
             metadata=visit1_metadata)
 
         expected_origin_visit = origin_visit1.copy()
         expected_origin_visit.update({
             'origin': origin_url,
             'visit': origin_visit1['visit'],
             'date': data.date_visit2,
             'type': data.type_visit2,
             'metadata': visit1_metadata,
             'status': 'full',
             'snapshot': data.snapshot['id'],
         })
 
         # when
         actual_origin_visit1 = swh_storage.origin_visit_get_by(
             origin_url,
             origin_visit1['visit'])
 
         # then
         assert actual_origin_visit1 == expected_origin_visit
 
     def test_origin_visit_get_by__unknown_origin(self, swh_storage):
         assert swh_storage.origin_visit_get_by('foo', 10) is None
 
     def test_origin_visit_upsert_new(self, swh_storage):
         # given
         swh_storage.origin_add_one(data.origin2)
         origin_url = data.origin2['url']
 
         # when
         swh_storage.origin_visit_upsert([
             {
                  'origin': origin_url,
                  'date': data.date_visit2,
                  'visit': 123,
                  'type': data.type_visit2,
                  'status': 'full',
                  'metadata': None,
                  'snapshot': None,
              },
             {
                  'origin': origin_url,
                  'date': '2018-01-01 23:00:00+00',
                  'visit': 1234,
                  'type': data.type_visit2,
                  'status': 'full',
                  'metadata': None,
                  'snapshot': None,
              },
         ])
 
         # then
         actual_origin_visits = list(swh_storage.origin_visit_get(
             origin_url))
         assert actual_origin_visits == [
             {
                 'origin': origin_url,
                 'date': data.date_visit2,
                 'visit': 123,
                 'type': data.type_visit2,
                 'status': 'full',
                 'metadata': None,
                 'snapshot': None,
             },
             {
                 'origin': origin_url,
                 'date': data.date_visit3,
                 'visit': 1234,
                 'type': data.type_visit2,
                 'status': 'full',
                 'metadata': None,
                 'snapshot': None,
             },
         ]
 
         data1 = {
             'origin': origin_url,
             'date': data.date_visit2,
             'visit': 123,
             'type': data.type_visit2,
             'status': 'full',
             'metadata': None,
             'snapshot': None,
         }
         data2 = {
             'origin': origin_url,
             'date': data.date_visit3,
             'visit': 1234,
             'type': data.type_visit2,
             'status': 'full',
             'metadata': None,
             'snapshot': None,
         }
         assert list(swh_storage.journal_writer.objects) == [
             ('origin', data.origin2),
             ('origin_visit', data1),
             ('origin_visit', data2)]
 
     def test_origin_visit_upsert_existing(self, swh_storage):
         # given
         swh_storage.origin_add_one(data.origin2)
         origin_url = data.origin2['url']
 
         # when
         origin_visit1 = swh_storage.origin_visit_add(
             origin_url,
             date=data.date_visit2,
             type=data.type_visit1,
         )
         swh_storage.origin_visit_upsert([{
              'origin': origin_url,
              'date': data.date_visit2,
              'visit': origin_visit1['visit'],
              'type': data.type_visit1,
              'status': 'full',
              'metadata': None,
              'snapshot': None,
          }])
 
         # then
         assert origin_visit1['origin'] == origin_url
         assert origin_visit1['visit'] is not None
 
         actual_origin_visits = list(swh_storage.origin_visit_get(
             origin_url))
         assert actual_origin_visits == [
             {
                 'origin': origin_url,
                 'date': data.date_visit2,
                 'visit': origin_visit1['visit'],
                 'type': data.type_visit1,
                 'status': 'full',
                 'metadata': None,
                 'snapshot': None,
             }]
 
         data1 = {
             'origin': origin_url,
             'date': data.date_visit2,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         data2 = {
             'origin': origin_url,
             'date': data.date_visit2,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'full',
             'metadata': None,
             'snapshot': None,
         }
         assert list(swh_storage.journal_writer.objects) == [
             ('origin', data.origin2),
             ('origin_visit', data1),
             ('origin_visit', data2)]
 
     def test_origin_visit_get_by_no_result(self, swh_storage):
         swh_storage.origin_add([data.origin])
         actual_origin_visit = swh_storage.origin_visit_get_by(
             data.origin['url'], 999)
         assert actual_origin_visit is None
 
     def test_origin_visit_get_latest(self, swh_storage):
         swh_storage.origin_add_one(data.origin)
         origin_url = data.origin['url']
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit1_id = origin_visit1['visit']
         origin_visit2 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit2,
             type=data.type_visit2,
         )
         visit2_id = origin_visit2['visit']
 
         # Add a visit with the same date as the previous one
         origin_visit3 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit2,
             type=data.type_visit2,
         )
         visit3_id = origin_visit3['visit']
 
         origin_visit1 = swh_storage.origin_visit_get_by(origin_url, visit1_id)
         origin_visit2 = swh_storage.origin_visit_get_by(origin_url, visit2_id)
         origin_visit3 = swh_storage.origin_visit_get_by(origin_url, visit3_id)
 
         # Two visits, both with no snapshot
         assert origin_visit3 == swh_storage.origin_visit_get_latest(origin_url)
         assert swh_storage.origin_visit_get_latest(
             origin_url, require_snapshot=True) is None
 
         # Add snapshot to visit1; require_snapshot=True makes it return
         # visit1 and require_snapshot=False still returns visit2
         swh_storage.snapshot_add([data.complete_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit1_id,
             snapshot=data.complete_snapshot['id'])
         assert {**origin_visit1, 'snapshot': data.complete_snapshot['id']} \
             == swh_storage.origin_visit_get_latest(
                 origin_url, require_snapshot=True)
 
         assert origin_visit3 == swh_storage.origin_visit_get_latest(origin_url)
 
         # Status filter: all three visits are status=ongoing, so no visit
         # returned
         assert swh_storage.origin_visit_get_latest(
                 origin_url, allowed_statuses=['full']) is None
 
         # Mark the first visit as completed and check status filter again
         swh_storage.origin_visit_update(
             origin_url,
             visit1_id, status='full')
         assert {
             **origin_visit1,
             'snapshot': data.complete_snapshot['id'],
             'status': 'full'} == swh_storage.origin_visit_get_latest(
                 origin_url, allowed_statuses=['full'])
 
         assert origin_visit3 == swh_storage.origin_visit_get_latest(origin_url)
 
         # Add snapshot to visit2 and check that the new snapshot is returned
         swh_storage.snapshot_add([data.empty_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit2_id,
             snapshot=data.empty_snapshot['id'])
         assert {**origin_visit2, 'snapshot': data.empty_snapshot['id']} == \
             swh_storage.origin_visit_get_latest(
                 origin_url, require_snapshot=True)
 
         assert origin_visit3 == swh_storage.origin_visit_get_latest(origin_url)
 
         # Check that the status filter is still working
         assert {
             **origin_visit1,
             'snapshot': data.complete_snapshot['id'],
             'status': 'full'} == swh_storage.origin_visit_get_latest(
                 origin_url, allowed_statuses=['full'])
 
         # Add snapshot to visit3 (same date as visit2)
         swh_storage.snapshot_add([data.complete_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit3_id, snapshot=data.complete_snapshot['id'])
         assert {
             **origin_visit1,
             'snapshot': data.complete_snapshot['id'],
             'status': 'full'} == swh_storage.origin_visit_get_latest(
                 origin_url, allowed_statuses=['full'])
         assert {
             **origin_visit1,
             'snapshot': data.complete_snapshot['id'],
             'status': 'full'} == swh_storage.origin_visit_get_latest(
                 origin_url, allowed_statuses=['full'], require_snapshot=True)
         assert {
             **origin_visit3,
             'snapshot': data.complete_snapshot['id']
             } == swh_storage.origin_visit_get_latest(origin_url)
 
         assert {
             **origin_visit3,
             'snapshot': data.complete_snapshot['id']
             } == swh_storage.origin_visit_get_latest(
                 origin_url, require_snapshot=True)
 
     def test_person_fullname_unicity(self, swh_storage):
         # given (person injection through revisions for example)
         revision = data.revision
 
         # create a revision with same committer fullname but wo name and email
         revision2 = copy.deepcopy(data.revision2)
         revision2['committer'] = dict(revision['committer'])
         revision2['committer']['email'] = None
         revision2['committer']['name'] = None
 
         swh_storage.revision_add([revision])
         swh_storage.revision_add([revision2])
 
         # when getting added revisions
         revisions = list(
             swh_storage.revision_get([revision['id'], revision2['id']]))
 
         # then
         # check committers are the same
         assert revisions[0]['committer'] == revisions[1]['committer']
 
     def test_snapshot_add_get_empty(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit_id = origin_visit1['visit']
 
         actual_result = swh_storage.snapshot_add([data.empty_snapshot])
         assert actual_result == {'snapshot:add': 1}
 
         swh_storage.origin_visit_update(
             origin_url, visit_id, snapshot=data.empty_snapshot['id'])
 
         by_id = swh_storage.snapshot_get(data.empty_snapshot['id'])
         assert by_id == {**data.empty_snapshot, 'next_branch': None}
 
         by_ov = swh_storage.snapshot_get_by_origin_visit(origin_url, visit_id)
         assert by_ov == {**data.empty_snapshot, 'next_branch': None}
 
         data1 = {
             'origin': origin_url,
             'date': data.date_visit1,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         data2 = {
             'origin': origin_url,
             'date': data.date_visit1,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': data.empty_snapshot['id'],
         }
         assert list(swh_storage.journal_writer.objects) == \
             [('origin', data.origin),
              ('origin_visit', data1),
              ('snapshot', data.empty_snapshot),
              ('origin_visit', data2)]
 
     def test_snapshot_add_get_complete(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit_id = origin_visit1['visit']
 
         actual_result = swh_storage.snapshot_add([data.complete_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit_id, snapshot=data.complete_snapshot['id'])
         assert actual_result == {'snapshot:add': 1}
 
         by_id = swh_storage.snapshot_get(data.complete_snapshot['id'])
         assert by_id == {**data.complete_snapshot, 'next_branch': None}
 
         by_ov = swh_storage.snapshot_get_by_origin_visit(origin_url, visit_id)
         assert by_ov == {**data.complete_snapshot, 'next_branch': None}
 
     def test_snapshot_add_many(self, swh_storage):
         actual_result = swh_storage.snapshot_add(
             [data.snapshot, data.complete_snapshot])
         assert actual_result == {'snapshot:add': 2}
 
         assert {**data.complete_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get(data.complete_snapshot['id'])
 
         assert {**data.snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get(data.snapshot['id'])
 
     def test_snapshot_add_many_incremental(self, swh_storage):
         actual_result = swh_storage.snapshot_add([data.complete_snapshot])
         assert actual_result == {'snapshot:add': 1}
 
         actual_result2 = swh_storage.snapshot_add(
             [data.snapshot, data.complete_snapshot])
         assert actual_result2 == {'snapshot:add': 1}
 
         assert {**data.complete_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get(data.complete_snapshot['id'])
 
         assert {**data.snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get(data.snapshot['id'])
 
     def test_snapshot_add_twice(self, swh_storage):
         actual_result = swh_storage.snapshot_add([data.empty_snapshot])
         assert actual_result == {'snapshot:add': 1}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('snapshot', data.empty_snapshot)]
 
         actual_result = swh_storage.snapshot_add([data.snapshot])
         assert actual_result == {'snapshot:add': 1}
 
         assert list(swh_storage.journal_writer.objects) \
             == [('snapshot', data.empty_snapshot),
                 ('snapshot', data.snapshot)]
 
     def test_snapshot_add_validation(self, swh_storage):
         snap = copy.deepcopy(data.snapshot)
         snap['branches'][b'foo'] = {'target_type': 'revision'}
 
         with pytest.raises(KeyError, match='target'):
             swh_storage.snapshot_add([snap])
 
         snap = copy.deepcopy(data.snapshot)
         snap['branches'][b'foo'] = {'target': b'\x42'*20}
 
         with pytest.raises(KeyError, match='target_type'):
             swh_storage.snapshot_add([snap])
 
     def test_snapshot_add_count_branches(self, swh_storage):
         actual_result = swh_storage.snapshot_add([data.complete_snapshot])
         assert actual_result == {'snapshot:add': 1}
 
         snp_id = data.complete_snapshot['id']
         snp_size = swh_storage.snapshot_count_branches(snp_id)
 
         expected_snp_size = {
             'alias': 1,
             'content': 1,
             'directory': 2,
             'release': 1,
             'revision': 1,
             'snapshot': 1,
             None: 1
         }
         assert snp_size == expected_snp_size
 
     def test_snapshot_add_get_paginated(self, swh_storage):
         swh_storage.snapshot_add([data.complete_snapshot])
 
         snp_id = data.complete_snapshot['id']
         branches = data.complete_snapshot['branches']
         branch_names = list(sorted(branches))
 
         # Test branch_from
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, branches_from=b'release')
 
         rel_idx = branch_names.index(b'release')
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 name: branches[name]
                 for name in branch_names[rel_idx:]
             },
             'next_branch': None,
         }
 
         assert snapshot == expected_snapshot
 
         # Test branches_count
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, branches_count=1)
 
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 branch_names[0]: branches[branch_names[0]],
             },
             'next_branch': b'content',
         }
         assert snapshot == expected_snapshot
 
         # test branch_from + branches_count
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, branches_from=b'directory', branches_count=3)
 
         dir_idx = branch_names.index(b'directory')
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 name: branches[name]
                 for name in branch_names[dir_idx:dir_idx + 3]
             },
             'next_branch': branch_names[dir_idx + 3],
         }
 
         assert snapshot == expected_snapshot
 
     def test_snapshot_add_get_filtered(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit_id = origin_visit1['visit']
 
         swh_storage.snapshot_add([data.complete_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit_id, snapshot=data.complete_snapshot['id'])
 
         snp_id = data.complete_snapshot['id']
         branches = data.complete_snapshot['branches']
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, target_types=['release', 'revision'])
 
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 name: tgt
                 for name, tgt in branches.items()
                 if tgt and tgt['target_type'] in ['release', 'revision']
             },
             'next_branch': None,
         }
 
         assert snapshot == expected_snapshot
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, target_types=['alias'])
 
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 name: tgt
                 for name, tgt in branches.items()
                 if tgt and tgt['target_type'] == 'alias'
             },
             'next_branch': None,
         }
 
         assert snapshot == expected_snapshot
 
     def test_snapshot_add_get_filtered_and_paginated(self, swh_storage):
         swh_storage.snapshot_add([data.complete_snapshot])
 
         snp_id = data.complete_snapshot['id']
         branches = data.complete_snapshot['branches']
         branch_names = list(sorted(branches))
 
         # Test branch_from
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, target_types=['directory', 'release'],
             branches_from=b'directory2')
 
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 name: branches[name]
                 for name in (b'directory2', b'release')
             },
             'next_branch': None,
         }
 
         assert snapshot == expected_snapshot
 
         # Test branches_count
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, target_types=['directory', 'release'],
             branches_count=1)
 
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 b'directory': branches[b'directory']
             },
             'next_branch': b'directory2',
         }
         assert snapshot == expected_snapshot
 
         # Test branches_count
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, target_types=['directory', 'release'],
             branches_count=2)
 
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 name: branches[name]
                 for name in (b'directory', b'directory2')
             },
             'next_branch': b'release',
         }
         assert snapshot == expected_snapshot
 
         # test branch_from + branches_count
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, target_types=['directory', 'release'],
             branches_from=b'directory2', branches_count=1)
 
         dir_idx = branch_names.index(b'directory2')
         expected_snapshot = {
             'id': snp_id,
             'branches': {
                 branch_names[dir_idx]: branches[branch_names[dir_idx]],
             },
             'next_branch': b'release',
         }
 
         assert snapshot == expected_snapshot
 
     def test_snapshot_add_get(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit_id = origin_visit1['visit']
 
         swh_storage.snapshot_add([data.snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit_id, snapshot=data.snapshot['id'])
 
         by_id = swh_storage.snapshot_get(data.snapshot['id'])
         assert by_id == {**data.snapshot, 'next_branch': None}
 
         by_ov = swh_storage.snapshot_get_by_origin_visit(origin_url, visit_id)
         assert by_ov == {**data.snapshot, 'next_branch': None}
 
         origin_visit_info = swh_storage.origin_visit_get_by(
             origin_url, visit_id)
         assert origin_visit_info['snapshot'] == data.snapshot['id']
 
     def test_snapshot_add_nonexistent_visit(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         visit_id = 54164461156
 
         swh_storage.journal_writer.objects[:] = []
 
         swh_storage.snapshot_add([data.snapshot])
 
         with pytest.raises(ValueError):
             swh_storage.origin_visit_update(
                 origin_url, visit_id, snapshot=data.snapshot['id'])
 
         assert list(swh_storage.journal_writer.objects) == [
             ('snapshot', data.snapshot)]
 
     def test_snapshot_add_twice__by_origin_visit(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit1_id = origin_visit1['visit']
         swh_storage.snapshot_add([data.snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit1_id, snapshot=data.snapshot['id'])
 
         by_ov1 = swh_storage.snapshot_get_by_origin_visit(
             origin_url, visit1_id)
         assert by_ov1 == {**data.snapshot, 'next_branch': None}
 
         origin_visit2 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit2,
             type=data.type_visit2,
         )
         visit2_id = origin_visit2['visit']
 
         swh_storage.snapshot_add([data.snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit2_id, snapshot=data.snapshot['id'])
 
         by_ov2 = swh_storage.snapshot_get_by_origin_visit(
             origin_url, visit2_id)
         assert by_ov2 == {**data.snapshot, 'next_branch': None}
 
         data1 = {
             'origin': origin_url,
             'date': data.date_visit1,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         data2 = {
             'origin': origin_url,
             'date': data.date_visit1,
             'visit': origin_visit1['visit'],
             'type': data.type_visit1,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': data.snapshot['id'],
         }
         data3 = {
             'origin': origin_url,
             'date': data.date_visit2,
             'visit': origin_visit2['visit'],
             'type': data.type_visit2,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': None,
         }
         data4 = {
             'origin': origin_url,
             'date': data.date_visit2,
             'visit': origin_visit2['visit'],
             'type': data.type_visit2,
             'status': 'ongoing',
             'metadata': None,
             'snapshot': data.snapshot['id'],
         }
         assert list(swh_storage.journal_writer.objects) \
             == [('origin', data.origin),
                 ('origin_visit', data1),
                 ('snapshot', data.snapshot),
                 ('origin_visit', data2),
                 ('origin_visit', data3),
                 ('origin_visit', data4)]
 
     def test_snapshot_get_latest(self, swh_storage):
         origin_url = data.origin['url']
         swh_storage.origin_add_one(data.origin)
         origin_url = data.origin['url']
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit1_id = origin_visit1['visit']
         origin_visit2 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit2,
             type=data.type_visit2,
         )
         visit2_id = origin_visit2['visit']
 
         # Add a visit with the same date as the previous one
         origin_visit3 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit2,
             type=data.type_visit3,
         )
         visit3_id = origin_visit3['visit']
 
         # Two visits, both with no snapshot: latest snapshot is None
         assert swh_storage.snapshot_get_latest(origin_url) is None
 
         # Add snapshot to visit1, latest snapshot = visit 1 snapshot
         swh_storage.snapshot_add([data.complete_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit1_id, snapshot=data.complete_snapshot['id'])
         assert {**data.complete_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get_latest(origin_url)
 
         # Status filter: all three visits are status=ongoing, so no snapshot
         # returned
         assert swh_storage.snapshot_get_latest(
                 origin_url,
                 allowed_statuses=['full']) is None
 
         # Mark the first visit as completed and check status filter again
         swh_storage.origin_visit_update(origin_url, visit1_id, status='full')
         assert {**data.complete_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get_latest(
                 origin_url,
                 allowed_statuses=['full'])
 
         # Add snapshot to visit2 and check that the new snapshot is returned
         swh_storage.snapshot_add([data.empty_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit2_id, snapshot=data.empty_snapshot['id'])
         assert {**data.empty_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get_latest(origin_url)
 
         # Check that the status filter is still working
         assert {**data.complete_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get_latest(
                 origin_url,
                 allowed_statuses=['full'])
 
         # Add snapshot to visit3 (same date as visit2) and check that
         # the new snapshot is returned
         swh_storage.snapshot_add([data.complete_snapshot])
         swh_storage.origin_visit_update(
             origin_url, visit3_id, snapshot=data.complete_snapshot['id'])
         assert {**data.complete_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get_latest(origin_url)
 
     def test_snapshot_get_latest__missing_snapshot(self, swh_storage):
         # Origin does not exist
         origin_url = data.origin['url']
         assert swh_storage.snapshot_get_latest(origin_url) is None
 
         swh_storage.origin_add_one(data.origin)
         origin_visit1 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit1,
             type=data.type_visit1,
         )
         visit1_id = origin_visit1['visit']
         origin_visit2 = swh_storage.origin_visit_add(
             origin=origin_url,
             date=data.date_visit2,
             type=data.type_visit2,
         )
         visit2_id = origin_visit2['visit']
 
         # Two visits, both with no snapshot: latest snapshot is None
         assert swh_storage.snapshot_get_latest(origin_url) is None
 
         # Add unknown snapshot to visit1, check that the inconsistency is
         # detected
         swh_storage.origin_visit_update(
             origin_url,
             visit1_id, snapshot=data.complete_snapshot['id'])
         with pytest.raises(ValueError):
             swh_storage.snapshot_get_latest(
                 origin_url)
 
         # Status filter: both visits are status=ongoing, so no snapshot
         # returned
         assert swh_storage.snapshot_get_latest(
             origin_url,
             allowed_statuses=['full']) is None
 
         # Mark the first visit as completed and check status filter again
         swh_storage.origin_visit_update(
             origin_url,
             visit1_id, status='full')
         with pytest.raises(ValueError):
             swh_storage.snapshot_get_latest(
                 origin_url,
                 allowed_statuses=['full']),
 
         # Actually add the snapshot and check status filter again
         swh_storage.snapshot_add([data.complete_snapshot])
         assert {**data.complete_snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get_latest(origin_url)
 
         # Add unknown snapshot to visit2 and check that the inconsistency
         # is detected
         swh_storage.origin_visit_update(
             origin_url,
             visit2_id, snapshot=data.snapshot['id'])
         with pytest.raises(ValueError):
             swh_storage.snapshot_get_latest(
                 origin_url)
 
         # Actually add that snapshot and check that the new one is returned
         swh_storage.snapshot_add([data.snapshot])
         assert{**data.snapshot, 'next_branch': None} \
             == swh_storage.snapshot_get_latest(origin_url)
 
     def test_snapshot_get_random(self, swh_storage):
         swh_storage.snapshot_add(
             [data.snapshot, data.empty_snapshot, data.complete_snapshot])
 
         assert swh_storage.snapshot_get_random() in {
             data.snapshot['id'], data.empty_snapshot['id'],
             data.complete_snapshot['id']}
 
     def test_stat_counters(self, swh_storage):
         expected_keys = ['content', 'directory',
                          'origin', 'revision']
 
         # Initially, all counters are 0
 
         swh_storage.refresh_stat_counters()
         counters = swh_storage.stat_counters()
         assert set(expected_keys) <= set(counters)
         for key in expected_keys:
             assert counters[key] == 0
 
         # Add a content. Only the content counter should increase.
 
         swh_storage.content_add([data.cont])
 
         swh_storage.refresh_stat_counters()
         counters = swh_storage.stat_counters()
 
         assert set(expected_keys) <= set(counters)
         for key in expected_keys:
             if key != 'content':
                 assert counters[key] == 0
         assert counters['content'] == 1
 
         # Add other objects. Check their counter increased as well.
 
         swh_storage.origin_add_one(data.origin2)
         origin_visit1 = swh_storage.origin_visit_add(
             origin=data.origin2['url'],
             date=data.date_visit2,
             type=data.type_visit2,
         )
         swh_storage.snapshot_add([data.snapshot])
         swh_storage.origin_visit_update(
             data.origin2['url'], origin_visit1['visit'],
             snapshot=data.snapshot['id'])
         swh_storage.directory_add([data.dir])
         swh_storage.revision_add([data.revision])
         swh_storage.release_add([data.release])
 
         swh_storage.refresh_stat_counters()
         counters = swh_storage.stat_counters()
         assert counters['content'] == 1
         assert counters['directory'] == 1
         assert counters['snapshot'] == 1
         assert counters['origin'] == 1
         assert counters['origin_visit'] == 1
         assert counters['revision'] == 1
         assert counters['release'] == 1
         assert counters['snapshot'] == 1
         if 'person' in counters:
             assert counters['person'] == 3
 
     def test_content_find_ctime(self, swh_storage):
         cont = data.cont.copy()
         del cont['data']
         now = datetime.datetime.now(tz=datetime.timezone.utc)
         cont['ctime'] = now
         swh_storage.content_add_metadata([cont])
 
         actually_present = swh_storage.content_find({'sha1': cont['sha1']})
 
         # check ctime up to one second
         dt = actually_present[0]['ctime'] - now
         assert abs(dt.total_seconds()) <= 1
         del actually_present[0]['ctime']
 
         assert actually_present[0] == {
             'sha1': cont['sha1'],
             'sha256': cont['sha256'],
             'sha1_git': cont['sha1_git'],
             'blake2s256': cont['blake2s256'],
             'length': cont['length'],
             'status': 'visible'
         }
 
     def test_content_find_with_present_content(self, swh_storage):
         # 1. with something to find
         cont = data.cont
         swh_storage.content_add([cont, data.cont2])
 
         actually_present = swh_storage.content_find(
             {'sha1': cont['sha1']}
             )
         assert 1 == len(actually_present)
         actually_present[0].pop('ctime')
 
         assert actually_present[0] == {
                 'sha1': cont['sha1'],
                 'sha256': cont['sha256'],
                 'sha1_git': cont['sha1_git'],
                 'blake2s256': cont['blake2s256'],
                 'length': cont['length'],
                 'status': 'visible'
             }
 
         # 2. with something to find
         actually_present = swh_storage.content_find(
             {'sha1_git': cont['sha1_git']})
         assert 1 == len(actually_present)
 
         actually_present[0].pop('ctime')
         assert actually_present[0] == {
                 'sha1': cont['sha1'],
                 'sha256': cont['sha256'],
                 'sha1_git': cont['sha1_git'],
                 'blake2s256': cont['blake2s256'],
                 'length': cont['length'],
                 'status': 'visible'
             }
 
         # 3. with something to find
         actually_present = swh_storage.content_find(
             {'sha256': cont['sha256']})
         assert 1 == len(actually_present)
 
         actually_present[0].pop('ctime')
         assert actually_present[0] == {
                 'sha1': cont['sha1'],
                 'sha256': cont['sha256'],
                 'sha1_git': cont['sha1_git'],
                 'blake2s256': cont['blake2s256'],
                 'length': cont['length'],
                 'status': 'visible'
             }
 
         # 4. with something to find
         actually_present = swh_storage.content_find({
             'sha1': cont['sha1'],
             'sha1_git': cont['sha1_git'],
             'sha256': cont['sha256'],
             'blake2s256': cont['blake2s256'],
         })
         assert 1 == len(actually_present)
 
         actually_present[0].pop('ctime')
         assert actually_present[0] == {
                 'sha1': cont['sha1'],
                 'sha256': cont['sha256'],
                 'sha1_git': cont['sha1_git'],
                 'blake2s256': cont['blake2s256'],
                 'length': cont['length'],
                 'status': 'visible'
             }
 
     def test_content_find_with_non_present_content(self, swh_storage):
         # 1. with something that does not exist
         missing_cont = data.missing_cont
 
         actually_present = swh_storage.content_find(
             {'sha1': missing_cont['sha1']})
 
         assert actually_present == []
 
         # 2. with something that does not exist
         actually_present = swh_storage.content_find(
             {'sha1_git': missing_cont['sha1_git']})
 
         assert actually_present == []
 
         # 3. with something that does not exist
         actually_present = swh_storage.content_find(
             {'sha256': missing_cont['sha256']})
 
         assert actually_present == []
 
     def test_content_find_with_duplicate_input(self, swh_storage):
         cont1 = data.cont
         duplicate_cont = cont1.copy()
 
         # Create fake data with colliding sha256 and blake2s256
         sha1_array = bytearray(duplicate_cont['sha1'])
         sha1_array[0] += 1
         duplicate_cont['sha1'] = bytes(sha1_array)
         sha1git_array = bytearray(duplicate_cont['sha1_git'])
         sha1git_array[0] += 1
         duplicate_cont['sha1_git'] = bytes(sha1git_array)
         # Inject the data
         swh_storage.content_add([cont1, duplicate_cont])
         finder = {'blake2s256': duplicate_cont['blake2s256'],
                   'sha256': duplicate_cont['sha256']}
         actual_result = list(swh_storage.content_find(finder))
 
         cont1.pop('data')
         duplicate_cont.pop('data')
         actual_result[0].pop('ctime')
         actual_result[1].pop('ctime')
 
         expected_result = [
            cont1, duplicate_cont
         ]
         for result in expected_result:
             assert result in actual_result
 
     def test_content_find_with_duplicate_sha256(self, swh_storage):
         cont1 = data.cont
         duplicate_cont = cont1.copy()
 
         # Create fake data with colliding sha256
         for hashalgo in ('sha1', 'sha1_git', 'blake2s256'):
             value = bytearray(duplicate_cont[hashalgo])
             value[0] += 1
             duplicate_cont[hashalgo] = bytes(value)
         swh_storage.content_add([cont1, duplicate_cont])
 
         finder = {
             'sha256': duplicate_cont['sha256']
             }
         actual_result = list(swh_storage.content_find(finder))
         assert len(actual_result) == 2
 
         cont1.pop('data')
         duplicate_cont.pop('data')
         actual_result[0].pop('ctime')
         actual_result[1].pop('ctime')
         expected_result = [
             cont1, duplicate_cont
         ]
         assert expected_result == sorted(actual_result,
                                          key=lambda x: x['sha1'])
 
         # Find with both sha256 and blake2s256
         finder = {
             'sha256': duplicate_cont['sha256'],
             'blake2s256': duplicate_cont['blake2s256']
         }
         actual_result = list(swh_storage.content_find(finder))
         assert len(actual_result) == 1
         actual_result[0].pop('ctime')
 
         expected_result = [duplicate_cont]
         assert actual_result[0] == duplicate_cont
 
     def test_content_find_with_duplicate_blake2s256(self, swh_storage):
         cont1 = data.cont
         duplicate_cont = cont1.copy()
 
         # Create fake data with colliding sha256 and blake2s256
         sha1_array = bytearray(duplicate_cont['sha1'])
         sha1_array[0] += 1
         duplicate_cont['sha1'] = bytes(sha1_array)
         sha1git_array = bytearray(duplicate_cont['sha1_git'])
         sha1git_array[0] += 1
         duplicate_cont['sha1_git'] = bytes(sha1git_array)
         sha256_array = bytearray(duplicate_cont['sha256'])
         sha256_array[0] += 1
         duplicate_cont['sha256'] = bytes(sha256_array)
         swh_storage.content_add([cont1, duplicate_cont])
         finder = {
             'blake2s256': duplicate_cont['blake2s256']
             }
         actual_result = list(swh_storage.content_find(finder))
 
         cont1.pop('data')
         duplicate_cont.pop('data')
         actual_result[0].pop('ctime')
         actual_result[1].pop('ctime')
         expected_result = [
             cont1, duplicate_cont
         ]
         for result in expected_result:
             assert result in actual_result
 
         # Find with both sha256 and blake2s256
         finder = {
             'sha256': duplicate_cont['sha256'],
             'blake2s256': duplicate_cont['blake2s256']
         }
         actual_result = list(swh_storage.content_find(finder))
 
         actual_result[0].pop('ctime')
 
         expected_result = [
             duplicate_cont
         ]
         assert expected_result == actual_result
 
     def test_content_find_bad_input(self, swh_storage):
         # 1. with bad input
         with pytest.raises(ValueError):
             swh_storage.content_find({})  # empty is bad
 
         # 2. with bad input
         with pytest.raises(ValueError):
             swh_storage.content_find(
                 {'unknown-sha1': 'something'})  # not the right key
 
     def test_object_find_by_sha1_git(self, swh_storage):
         sha1_gits = [b'00000000000000000000']
         expected = {
             b'00000000000000000000': [],
         }
 
         swh_storage.content_add([data.cont])
         sha1_gits.append(data.cont['sha1_git'])
         expected[data.cont['sha1_git']] = [{
             'sha1_git': data.cont['sha1_git'],
             'type': 'content',
             'id': data.cont['sha1'],
         }]
 
         swh_storage.directory_add([data.dir])
         sha1_gits.append(data.dir['id'])
         expected[data.dir['id']] = [{
             'sha1_git': data.dir['id'],
             'type': 'directory',
             'id': data.dir['id'],
         }]
 
         swh_storage.revision_add([data.revision])
         sha1_gits.append(data.revision['id'])
         expected[data.revision['id']] = [{
             'sha1_git': data.revision['id'],
             'type': 'revision',
             'id': data.revision['id'],
         }]
 
         swh_storage.release_add([data.release])
         sha1_gits.append(data.release['id'])
         expected[data.release['id']] = [{
             'sha1_git': data.release['id'],
             'type': 'release',
             'id': data.release['id'],
         }]
 
         ret = swh_storage.object_find_by_sha1_git(sha1_gits)
         for val in ret.values():
             for obj in val:
                 if 'object_id' in obj:
                     del obj['object_id']
 
         assert expected == ret
 
     def test_tool_add(self, swh_storage):
         tool = {
             'name': 'some-unknown-tool',
             'version': 'some-version',
             'configuration': {"debian-package": "some-package"},
         }
 
         actual_tool = swh_storage.tool_get(tool)
         assert actual_tool is None  # does not exist
 
         # add it
         actual_tools = swh_storage.tool_add([tool])
 
         assert len(actual_tools) == 1
         actual_tool = actual_tools[0]
         assert actual_tool is not None  # now it exists
         new_id = actual_tool.pop('id')
         assert actual_tool == tool
 
         actual_tools2 = swh_storage.tool_add([tool])
         actual_tool2 = actual_tools2[0]
         assert actual_tool2 is not None  # now it exists
         new_id2 = actual_tool2.pop('id')
 
         assert new_id == new_id2
         assert actual_tool == actual_tool2
 
     def test_tool_add_multiple(self, swh_storage):
         tool = {
             'name': 'some-unknown-tool',
             'version': 'some-version',
             'configuration': {"debian-package": "some-package"},
         }
 
         actual_tools = list(swh_storage.tool_add([tool]))
         assert len(actual_tools) == 1
 
         new_tools = [tool, {
             'name': 'yet-another-tool',
             'version': 'version',
             'configuration': {},
         }]
 
         actual_tools = swh_storage.tool_add(new_tools)
         assert len(actual_tools) == 2
 
         # order not guaranteed, so we iterate over results to check
         for tool in actual_tools:
             _id = tool.pop('id')
             assert _id is not None
             assert tool in new_tools
 
     def test_tool_get_missing(self, swh_storage):
         tool = {
             'name': 'unknown-tool',
             'version': '3.1.0rc2-31-ga2cbb8c',
             'configuration': {"command_line": "nomossa <filepath>"},
         }
 
         actual_tool = swh_storage.tool_get(tool)
 
         assert actual_tool is None
 
     def test_tool_metadata_get_missing_context(self, swh_storage):
         tool = {
             'name': 'swh-metadata-translator',
             'version': '0.0.1',
             'configuration': {"context": "unknown-context"},
         }
 
         actual_tool = swh_storage.tool_get(tool)
 
         assert actual_tool is None
 
     def test_tool_metadata_get(self, swh_storage):
         tool = {
             'name': 'swh-metadata-translator',
             'version': '0.0.1',
             'configuration': {"type": "local", "context": "npm"},
         }
         expected_tool = swh_storage.tool_add([tool])[0]
 
         # when
         actual_tool = swh_storage.tool_get(tool)
 
         # then
         assert expected_tool == actual_tool
 
     def test_metadata_provider_get(self, swh_storage):
         # given
         no_provider = swh_storage.metadata_provider_get(6459456445615)
         assert no_provider is None
         # when
         provider_id = swh_storage.metadata_provider_add(
             data.provider['name'],
             data.provider['type'],
             data.provider['url'],
             data.provider['metadata'])
 
         actual_provider = swh_storage.metadata_provider_get(provider_id)
         expected_provider = {
             'provider_name': data.provider['name'],
             'provider_url': data.provider['url']
         }
         # then
         del actual_provider['id']
         assert actual_provider, expected_provider
 
     def test_metadata_provider_get_by(self, swh_storage):
         # given
         no_provider = swh_storage.metadata_provider_get_by({
             'provider_name': data.provider['name'],
             'provider_url': data.provider['url']
         })
         assert no_provider is None
         # when
         provider_id = swh_storage.metadata_provider_add(
             data.provider['name'],
             data.provider['type'],
             data.provider['url'],
             data.provider['metadata'])
 
         actual_provider = swh_storage.metadata_provider_get_by({
             'provider_name': data.provider['name'],
             'provider_url': data.provider['url']
         })
         # then
         assert provider_id, actual_provider['id']
 
     def test_origin_metadata_add(self, swh_storage):
         # given
         origin = data.origin
         swh_storage.origin_add([origin])[0]
 
         tools = swh_storage.tool_add([data.metadata_tool])
         tool = tools[0]
 
         swh_storage.metadata_provider_add(
                            data.provider['name'],
                            data.provider['type'],
                            data.provider['url'],
                            data.provider['metadata'])
         provider = swh_storage.metadata_provider_get_by({
                             'provider_name': data.provider['name'],
                             'provider_url': data.provider['url']
                       })
 
         # when adding for the same origin 2 metadatas
         n_om = len(list(swh_storage.origin_metadata_get_by(origin['url'])))
         swh_storage.origin_metadata_add(
                     origin['url'],
                     data.origin_metadata['discovery_date'],
                     provider['id'],
                     tool['id'],
                     data.origin_metadata['metadata'])
         swh_storage.origin_metadata_add(
                     origin['url'],
                     '2015-01-01 23:00:00+00',
                     provider['id'],
                     tool['id'],
                     data.origin_metadata2['metadata'])
         n_actual_om = len(list(
             swh_storage.origin_metadata_get_by(origin['url'])))
         # then
         assert n_actual_om == n_om + 2
 
     def test_origin_metadata_get(self, swh_storage):
         # given
         origin_url = data.origin['url']
         origin_url2 = data.origin2['url']
         swh_storage.origin_add([data.origin])
         swh_storage.origin_add([data.origin2])
 
         swh_storage.metadata_provider_add(data.provider['name'],
                                           data.provider['type'],
                                           data.provider['url'],
                                           data.provider['metadata'])
         provider = swh_storage.metadata_provider_get_by({
             'provider_name': data.provider['name'],
             'provider_url': data.provider['url']
         })
         tool = swh_storage.tool_add([data.metadata_tool])[0]
         # when adding for the same origin 2 metadatas
         swh_storage.origin_metadata_add(
                     origin_url,
                     data.origin_metadata['discovery_date'],
                     provider['id'],
                     tool['id'],
                     data.origin_metadata['metadata'])
         swh_storage.origin_metadata_add(
                     origin_url2,
                     data.origin_metadata2['discovery_date'],
                     provider['id'],
                     tool['id'],
                     data.origin_metadata2['metadata'])
         swh_storage.origin_metadata_add(
                     origin_url,
                     data.origin_metadata2['discovery_date'],
                     provider['id'],
                     tool['id'],
                     data.origin_metadata2['metadata'])
         all_metadatas = list(sorted(swh_storage.origin_metadata_get_by(
             origin_url), key=lambda x: x['discovery_date']))
         metadatas_for_origin2 = list(swh_storage.origin_metadata_get_by(
             origin_url2))
         expected_results = [{
             'origin_url': origin_url,
             'discovery_date': datetime.datetime(
                                 2015, 1, 1, 23, 0,
                                 tzinfo=datetime.timezone.utc),
             'metadata': {
                 'name': 'test_origin_metadata',
                 'version': '0.0.1'
             },
             'provider_id': provider['id'],
             'provider_name': 'hal',
             'provider_type': 'deposit-client',
             'provider_url': 'http:///hal/inria',
             'tool_id': tool['id']
         }, {
             'origin_url': origin_url,
             'discovery_date': datetime.datetime(
                                 2017, 1, 1, 23, 0,
                                 tzinfo=datetime.timezone.utc),
             'metadata': {
                 'name': 'test_origin_metadata',
                 'version': '0.0.1'
             },
             'provider_id': provider['id'],
             'provider_name': 'hal',
             'provider_type': 'deposit-client',
             'provider_url': 'http:///hal/inria',
             'tool_id': tool['id']
         }]
 
         # then
         assert len(all_metadatas) == 2
         assert len(metadatas_for_origin2) == 1
         assert all_metadatas == expected_results
 
     def test_metadata_provider_add(self, swh_storage):
         provider = {
             'provider_name': 'swMATH',
             'provider_type': 'registry',
             'provider_url': 'http://www.swmath.org/',
             'metadata': {
                 'email': 'contact@swmath.org',
                 'license': 'All rights reserved'
             }
         }
         provider['id'] = provider_id = swh_storage.metadata_provider_add(
             **provider)
         assert provider == swh_storage.metadata_provider_get_by(
             {'provider_name': 'swMATH',
              'provider_url': 'http://www.swmath.org/'})
         assert provider == swh_storage.metadata_provider_get(provider_id)
 
     def test_origin_metadata_get_by_provider_type(self, swh_storage):
         # given
         origin_url = data.origin['url']
         origin_url2 = data.origin2['url']
         swh_storage.origin_add([data.origin])
         swh_storage.origin_add([data.origin2])
         provider1_id = swh_storage.metadata_provider_add(
                            data.provider['name'],
                            data.provider['type'],
                            data.provider['url'],
                            data.provider['metadata'])
         provider1 = swh_storage.metadata_provider_get_by({
                             'provider_name': data.provider['name'],
                             'provider_url': data.provider['url']
                    })
         assert provider1 == swh_storage.metadata_provider_get(provider1_id)
 
         provider2_id = swh_storage.metadata_provider_add(
                             'swMATH',
                             'registry',
                             'http://www.swmath.org/',
                             {'email': 'contact@swmath.org',
                              'license': 'All rights reserved'})
         provider2 = swh_storage.metadata_provider_get_by({
                             'provider_name': 'swMATH',
                             'provider_url': 'http://www.swmath.org/'
                    })
         assert provider2 == swh_storage.metadata_provider_get(provider2_id)
 
         # using the only tool now inserted in the data.sql, but for this
         # provider should be a crawler tool (not yet implemented)
         tool = swh_storage.tool_add([data.metadata_tool])[0]
 
         # when adding for the same origin 2 metadatas
         swh_storage.origin_metadata_add(
             origin_url,
             data.origin_metadata['discovery_date'],
             provider1['id'],
             tool['id'],
             data.origin_metadata['metadata'])
         swh_storage.origin_metadata_add(
             origin_url2,
             data.origin_metadata2['discovery_date'],
             provider2['id'],
             tool['id'],
             data.origin_metadata2['metadata'])
         provider_type = 'registry'
         m_by_provider = list(swh_storage.origin_metadata_get_by(
             origin_url2,
             provider_type))
         for item in m_by_provider:
             if 'id' in item:
                 del item['id']
         expected_results = [{
             'origin_url': origin_url2,
             'discovery_date': datetime.datetime(
                                 2017, 1, 1, 23, 0,
                                 tzinfo=datetime.timezone.utc),
             'metadata': {
                 'name': 'test_origin_metadata',
                 'version': '0.0.1'
             },
             'provider_id': provider2['id'],
             'provider_name': 'swMATH',
             'provider_type': provider_type,
             'provider_url': 'http://www.swmath.org/',
             'tool_id': tool['id']
         }]
         # then
 
         assert len(m_by_provider) == 1
         assert m_by_provider == expected_results
 
 
 class TestStorageGeneratedData:
     def assert_contents_ok(self, expected_contents, actual_contents,
                            keys_to_check={'sha1', 'data'}):
         """Assert that a given list of contents matches on a given set of keys.
 
         """
         for k in keys_to_check:
             expected_list = set([c.get(k) for c in expected_contents])
             actual_list = set([c.get(k) for c in actual_contents])
             assert actual_list == expected_list, k
 
     def test_generate_content_get(self, swh_storage, swh_contents):
         contents_with_data = [c for c in swh_contents
                               if c['status'] != 'absent']
         # input the list of sha1s we want from storage
         get_sha1s = [c['sha1'] for c in contents_with_data]
 
         # retrieve contents
         actual_contents = list(swh_storage.content_get(get_sha1s))
         assert None not in actual_contents
         self.assert_contents_ok(contents_with_data, actual_contents)
 
     def test_generate_content_get_metadata(self, swh_storage, swh_contents):
         # input the list of sha1s we want from storage
         expected_contents = [c for c in swh_contents
                              if c['status'] != 'absent']
         get_sha1s = [c['sha1'] for c in expected_contents]
 
         # retrieve contents
         actual_contents = list(swh_storage.content_get_metadata(get_sha1s))
 
         assert len(actual_contents) == len(get_sha1s)
 
         keys_to_check = {'length', 'status',
                          'sha1', 'sha1_git', 'sha256', 'blake2s256'}
         self.assert_contents_ok(expected_contents, actual_contents,
                                 keys_to_check=keys_to_check)
 
     def test_generate_content_get_range(self, swh_storage, swh_contents):
         """content_get_range returns complete range"""
         present_contents = [c for c in swh_contents
                             if c['status'] != 'absent']
 
         get_sha1s = sorted([c['sha1'] for c in swh_contents
                             if c['status'] != 'absent'])
         start = get_sha1s[2]
         end = get_sha1s[-2]
         actual_result = swh_storage.content_get_range(start, end)
 
         assert actual_result['next'] is None
 
         actual_contents = actual_result['contents']
         expected_contents = [c for c in present_contents
                              if start <= c['sha1'] <= end]
         if expected_contents:
             self.assert_contents_ok(
                 expected_contents, actual_contents, ['sha1'])
         else:
             assert actual_contents == []
 
     def test_generate_content_get_range_full(self, swh_storage, swh_contents):
         """content_get_range for a full range returns all available contents"""
         present_contents = [c for c in swh_contents
                             if c['status'] != 'absent']
 
         start = b'0' * 40
         end = b'f' * 40
         actual_result = swh_storage.content_get_range(start, end)
         assert actual_result['next'] is None
 
         actual_contents = actual_result['contents']
         expected_contents = [c for c in present_contents
                              if start <= c['sha1'] <= end]
         if expected_contents:
             self.assert_contents_ok(
                 expected_contents, actual_contents, ['sha1'])
         else:
             assert actual_contents == []
 
     def test_generate_content_get_range_empty(self, swh_storage, swh_contents):
         """content_get_range for an empty range returns nothing"""
         start = b'0' * 40
         end = b'f' * 40
         actual_result = swh_storage.content_get_range(end, start)
         assert actual_result['next'] is None
         assert len(actual_result['contents']) == 0
 
     def test_generate_content_get_range_limit_none(self, swh_storage):
         """content_get_range call with wrong limit input should fail"""
         with pytest.raises(ValueError) as e:
             swh_storage.content_get_range(start=None, end=None, limit=None)
 
         assert e.value.args == ('Development error: limit should not be None',)
 
     def test_generate_content_get_range_no_limit(
             self, swh_storage, swh_contents):
         """content_get_range returns contents within range provided"""
         # input the list of sha1s we want from storage
         get_sha1s = sorted([c['sha1'] for c in swh_contents
                             if c['status'] != 'absent'])
         start = get_sha1s[0]
         end = get_sha1s[-1]
 
         # retrieve contents
         actual_result = swh_storage.content_get_range(start, end)
 
         actual_contents = actual_result['contents']
         assert actual_result['next'] is None
         assert len(actual_contents) == len(get_sha1s)
 
         expected_contents = [c for c in swh_contents
                              if c['status'] != 'absent']
         self.assert_contents_ok(
             expected_contents, actual_contents, ['sha1'])
 
     def test_generate_content_get_range_limit(self, swh_storage, swh_contents):
         """content_get_range paginates results if limit exceeded"""
         contents_map = {c['sha1']: c for c in swh_contents}
 
         # input the list of sha1s we want from storage
         get_sha1s = sorted([c['sha1'] for c in swh_contents
                             if c['status'] != 'absent'])
         start = get_sha1s[0]
         end = get_sha1s[-1]
 
         # retrieve contents limited to n-1 results
         limited_results = len(get_sha1s) - 1
         actual_result = swh_storage.content_get_range(
             start, end, limit=limited_results)
 
         actual_contents = actual_result['contents']
         assert actual_result['next'] == get_sha1s[-1]
         assert len(actual_contents) == limited_results
 
         expected_contents = [contents_map[sha1] for sha1 in get_sha1s[:-1]]
         self.assert_contents_ok(
             expected_contents, actual_contents, ['sha1'])
 
         # retrieve next part
         actual_results2 = swh_storage.content_get_range(start=end, end=end)
         assert actual_results2['next'] is None
         actual_contents2 = actual_results2['contents']
         assert len(actual_contents2) == 1
 
         self.assert_contents_ok(
             [contents_map[get_sha1s[-1]]], actual_contents2, ['sha1'])
 
     def test_origin_get_range_from_zero(self, swh_storage, swh_origins):
         actual_origins = list(
             swh_storage.origin_get_range(origin_from=0,
                                          origin_count=0))
         assert len(actual_origins) == 0
 
         actual_origins = list(
             swh_storage.origin_get_range(origin_from=0,
                                          origin_count=1))
         assert len(actual_origins) == 1
         assert actual_origins[0]['id'] == 1
         assert actual_origins[0]['url'] == swh_origins[0]['url']
 
     @pytest.mark.parametrize('origin_from,origin_count', [
         (1, 1), (1, 10), (1, 20), (1, 101), (11, 0),
         (11, 10), (91, 11)])
     def test_origin_get_range(
             self, swh_storage, swh_origins, origin_from, origin_count):
         actual_origins = list(
             swh_storage.origin_get_range(origin_from=origin_from,
                                          origin_count=origin_count))
 
         origins_with_id = list(enumerate(swh_origins, start=1))
         expected_origins = [
             {
                 'url': origin['url'],
                 'id': origin_id,
             }
             for (origin_id, origin)
             in origins_with_id[origin_from-1:origin_from+origin_count-1]
         ]
 
         assert actual_origins == expected_origins
 
+    @pytest.mark.parametrize('limit', [1, 7, 10, 100, 1000])
+    def test_origin_list(self, swh_storage, swh_origins, limit):
+        returned_origins = []
+
+        page_token = None
+        i = 0
+        while True:
+            result = swh_storage.origin_list(
+                page_token=page_token, limit=limit)
+            assert len(result['origins']) <= limit
+
+            returned_origins.extend(
+                origin['url'] for origin in result['origins'])
+
+            i += 1
+            page_token = result.get('next_page_token')
+
+            if page_token is None:
+                assert i*limit >= len(swh_origins)
+                break
+            else:
+                assert len(result['origins']) == limit
+
+        expected_origins = [origin['url'] for origin in swh_origins]
+        assert sorted(returned_origins) == sorted(expected_origins)
+
     ORIGINS = [
         'https://github.com/user1/repo1',
         'https://github.com/user2/repo1',
         'https://github.com/user3/repo1',
         'https://gitlab.com/user1/repo1',
         'https://gitlab.com/user2/repo1',
         'https://forge.softwareheritage.org/source/repo1',
     ]
 
     def test_origin_count(self, swh_storage):
         swh_storage.origin_add([{'url': url} for url in self.ORIGINS])
 
         assert swh_storage.origin_count('github') == 3
         assert swh_storage.origin_count('gitlab') == 2
         assert swh_storage.origin_count('.*user.*', regexp=True) == 5
         assert swh_storage.origin_count('.*user.*', regexp=False) == 0
         assert swh_storage.origin_count('.*user1.*', regexp=True) == 2
         assert swh_storage.origin_count('.*user1.*', regexp=False) == 0
 
     def test_origin_count_with_visit_no_visits(self, swh_storage):
         swh_storage.origin_add([{'url': url} for url in self.ORIGINS])
 
         # none of them have visits, so with_visit=True => 0
         assert swh_storage.origin_count('github', with_visit=True) == 0
         assert swh_storage.origin_count('gitlab', with_visit=True) == 0
         assert swh_storage.origin_count('.*user.*', regexp=True,
                                         with_visit=True) == 0
         assert swh_storage.origin_count('.*user.*', regexp=False,
                                         with_visit=True) == 0
         assert swh_storage.origin_count('.*user1.*', regexp=True,
                                         with_visit=True) == 0
         assert swh_storage.origin_count('.*user1.*', regexp=False,
                                         with_visit=True) == 0
 
     def test_origin_count_with_visit_with_visits_no_snapshot(
             self, swh_storage):
         swh_storage.origin_add([{'url': url} for url in self.ORIGINS])
         now = datetime.datetime.now(tz=datetime.timezone.utc)
 
         swh_storage.origin_visit_add(
             origin='https://github.com/user1/repo1', date=now, type='git')
 
         assert swh_storage.origin_count('github', with_visit=False) == 3
         # it has a visit, but no snapshot, so with_visit=True => 0
         assert swh_storage.origin_count('github', with_visit=True) == 0
 
         assert swh_storage.origin_count('gitlab', with_visit=False) == 2
         # these gitlab origins have no visit
         assert swh_storage.origin_count('gitlab', with_visit=True) == 0
 
         assert swh_storage.origin_count('github.*user1', regexp=True,
                                         with_visit=False) == 1
         assert swh_storage.origin_count('github.*user1', regexp=True,
                                         with_visit=True) == 0
         assert swh_storage.origin_count('github', regexp=True,
                                         with_visit=True) == 0
 
     def test_origin_count_with_visit_with_visits_and_snapshot(
             self, swh_storage):
         swh_storage.origin_add([{'url': url} for url in self.ORIGINS])
         now = datetime.datetime.now(tz=datetime.timezone.utc)
 
         swh_storage.snapshot_add([data.snapshot])
         visit = swh_storage.origin_visit_add(
             origin='https://github.com/user1/repo1', date=now, type='git')
         swh_storage.origin_visit_update(
             origin='https://github.com/user1/repo1', visit_id=visit['visit'],
             snapshot=data.snapshot['id'])
 
         assert swh_storage.origin_count('github', with_visit=False) == 3
         # github/user1 has a visit and a snapshot, so with_visit=True => 1
         assert swh_storage.origin_count('github', with_visit=True) == 1
 
         assert swh_storage.origin_count('github.*user1', regexp=True,
                                         with_visit=False) == 1
         assert swh_storage.origin_count('github.*user1', regexp=True,
                                         with_visit=True) == 1
         assert swh_storage.origin_count('github', regexp=True,
                                         with_visit=True) == 1
 
     @settings(suppress_health_check=[HealthCheck.too_slow])
     @given(strategies.lists(objects(), max_size=2))
     def test_add_arbitrary(self, swh_storage, objects):
         for (obj_type, obj) in objects:
             obj = obj.to_dict()
             if obj_type == 'origin_visit':
                 origin = obj.pop('origin')
                 swh_storage.origin_add_one({'url': origin})
                 if 'visit' in obj:
                     del obj['visit']
                 swh_storage.origin_visit_add(
                     origin, obj['date'], obj['type'])
             else:
                 method = getattr(swh_storage, obj_type + '_add')
                 try:
                     method([obj])
                 except HashCollision:
                     pass
 
 
 @pytest.mark.db
 class TestLocalStorage:
     """Test the local storage"""
     # This test is only relevant on the local storage, with an actual
     # objstorage raising an exception
     def test_content_add_objstorage_exception(self, swh_storage):
         swh_storage.objstorage.add = Mock(
             side_effect=Exception('mocked broken objstorage')
         )
 
         with pytest.raises(Exception) as e:
             swh_storage.content_add([data.cont])
 
         assert e.value.args == ('mocked broken objstorage',)
         missing = list(swh_storage.content_missing([data.cont]))
         assert missing == [data.cont['sha1']]
 
 
 @pytest.mark.db
 class TestStorageRaceConditions:
     @pytest.mark.xfail
     def test_content_add_race(self, swh_storage):
 
         results = queue.Queue()
 
         def thread():
             try:
                 with db_transaction(swh_storage) as (db, cur):
                     ret = swh_storage.content_add([data.cont], db=db,
                                                   cur=cur)
                 results.put((threading.get_ident(), 'data', ret))
             except Exception as e:
                 results.put((threading.get_ident(), 'exc', e))
 
         t1 = threading.Thread(target=thread)
         t2 = threading.Thread(target=thread)
         t1.start()
         # this avoids the race condition
         # import time
         # time.sleep(1)
         t2.start()
         t1.join()
         t2.join()
 
         r1 = results.get(block=False)
         r2 = results.get(block=False)
 
         with pytest.raises(queue.Empty):
             results.get(block=False)
         assert r1[0] != r2[0]
         assert r1[1] == 'data', 'Got exception %r in Thread%s' % (r1[2], r1[0])
         assert r2[1] == 'data', 'Got exception %r in Thread%s' % (r2[2], r2[0])
 
 
 @pytest.mark.db
 class TestPgStorage:
     """This class is dedicated for the rare case where the schema needs to
        be altered dynamically.
 
        Otherwise, the tests could be blocking when ran altogether.
 
     """
     def test_content_update(self, swh_storage):
         swh_storage.journal_writer = None  # TODO, not supported
 
         cont = copy.deepcopy(data.cont)
 
         swh_storage.content_add([cont])
         # alter the sha1_git for example
         cont['sha1_git'] = hash_to_bytes(
             '3a60a5275d0333bf13468e8b3dcab90f4046e654')
 
         swh_storage.content_update([cont], keys=['sha1_git'])
 
         with db_transaction(swh_storage) as (_, cur):
             cur.execute('SELECT sha1, sha1_git, sha256, length, status'
                         ' FROM content WHERE sha1 = %s',
                         (cont['sha1'],))
             datum = cur.fetchone()
 
         assert datum == (cont['sha1'], cont['sha1_git'], cont['sha256'],
                          cont['length'], 'visible')
 
     def test_content_update_with_new_cols(self, swh_storage):
         swh_storage.journal_writer = None  # TODO, not supported
 
         with db_transaction(swh_storage) as (_, cur):
             cur.execute("""alter table content
                            add column test text default null,
                            add column test2 text default null""")
 
         cont = copy.deepcopy(data.cont2)
         swh_storage.content_add([cont])
         cont['test'] = 'value-1'
         cont['test2'] = 'value-2'
 
         swh_storage.content_update([cont], keys=['test', 'test2'])
         with db_transaction(swh_storage) as (_, cur):
             cur.execute(
                 '''SELECT sha1, sha1_git, sha256, length, status,
                    test, test2
                    FROM content WHERE sha1 = %s''',
                 (cont['sha1'],))
 
             datum = cur.fetchone()
 
         assert datum == (cont['sha1'], cont['sha1_git'], cont['sha256'],
                          cont['length'], 'visible',
                          cont['test'], cont['test2'])
 
         with db_transaction(swh_storage) as (_, cur):
             cur.execute("""alter table content drop column test,
                                                drop column test2""")
 
     def test_content_add_db(self, swh_storage):
         cont = data.cont
 
         actual_result = swh_storage.content_add([cont])
 
         assert actual_result == {
             'content:add': 1,
             'content:add:bytes': cont['length'],
             'skipped_content:add': 0
             }
 
         if hasattr(swh_storage, 'objstorage'):
             assert cont['sha1'] in swh_storage.objstorage
 
         with db_transaction(swh_storage) as (_, cur):
             cur.execute('SELECT sha1, sha1_git, sha256, length, status'
                         ' FROM content WHERE sha1 = %s',
                         (cont['sha1'],))
             datum = cur.fetchone()
 
         assert datum == (cont['sha1'], cont['sha1_git'], cont['sha256'],
                          cont['length'], 'visible')
 
         expected_cont = cont.copy()
         del expected_cont['data']
         journal_objects = list(swh_storage.journal_writer.objects)
         for (obj_type, obj) in journal_objects:
             del obj['ctime']
         assert journal_objects == [('content', expected_cont)]
 
     def test_content_add_metadata_db(self, swh_storage):
         cont = data.cont
         del cont['data']
         cont['ctime'] = datetime.datetime.now()
 
         actual_result = swh_storage.content_add_metadata([cont])
 
         assert actual_result == {
             'content:add': 1,
             'skipped_content:add': 0
             }
 
         if hasattr(swh_storage, 'objstorage'):
             assert cont['sha1'] not in swh_storage.objstorage
         with db_transaction(swh_storage) as (_, cur):
             cur.execute('SELECT sha1, sha1_git, sha256, length, status'
                         ' FROM content WHERE sha1 = %s',
                         (cont['sha1'],))
             datum = cur.fetchone()
         assert datum == (cont['sha1'], cont['sha1_git'], cont['sha256'],
                          cont['length'], 'visible')
 
         assert list(swh_storage.journal_writer.objects) == [('content', cont)]
 
     def test_skipped_content_add_db(self, swh_storage):
         cont = data.skipped_cont
         cont2 = data.skipped_cont2
         cont2['blake2s256'] = None
 
         actual_result = swh_storage.content_add([cont, cont, cont2])
 
         assert actual_result == {
             'content:add': 0,
             'content:add:bytes': 0,
             'skipped_content:add': 2,
             }
 
         with db_transaction(swh_storage) as (_, cur):
             cur.execute('SELECT sha1, sha1_git, sha256, blake2s256, '
                         'length, status, reason '
                         'FROM skipped_content ORDER BY sha1_git')
 
             dbdata = cur.fetchall()
 
         assert len(dbdata) == 2
         assert dbdata[0] == (cont['sha1'], cont['sha1_git'], cont['sha256'],
                              cont['blake2s256'], cont['length'], 'absent',
                              'Content too long')
 
         assert dbdata[1] == (cont2['sha1'], cont2['sha1_git'], cont2['sha256'],
                              cont2['blake2s256'], cont2['length'], 'absent',
                              'Content too long')