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# Copyright (C) 2015-2021 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
"""Loader in charge of injecting either new or existing svn mirrors to
swh-storage.
"""
from datetime import datetime
from mmap import ACCESS_WRITE, mmap
import os
import pty
import re
import shutil
from subprocess import Popen
import tempfile
from typing import Dict, Iterator, List, Optional, Sequence, Tuple
from subvertpy import SubversionException
from swh.loader.core.loader import BaseLoader
from swh.loader.core.utils import clean_dangling_folders
from swh.loader.exception import NotFound
from swh.loader.svn.svn import SvnRepo
from swh.model import from_disk, hashutil
from swh.model.model import (
Content,
Directory,
Origin,
Revision,
SkippedContent,
Snapshot,
SnapshotBranch,
TargetType,
)
from swh.storage.algos.snapshot import snapshot_get_latest
from swh.storage.interface import StorageInterface
from . import converters
from .exception import SvnLoaderHistoryAltered, SvnLoaderUneventful
from .utils import (
OutputStream,
init_svn_repo_from_archive_dump,
init_svn_repo_from_dump,
)
DEFAULT_BRANCH = b"HEAD"
TEMPORARY_DIR_PREFIX_PATTERN = "swh.loader.svn."
SUBVERSION_ERROR = re.compile(r".*(E[0-9]{6}):.*")
SUBVERSION_NOT_FOUND = "E170013"
class SvnLoader(BaseLoader):
"""SVN loader. The repository is either remote or local. The loader deals with
update on an already previously loaded repository.
"""
visit_type = "svn"
def __init__(
self,
storage: StorageInterface,
url: str,
origin_url: Optional[str] = None,
visit_date: Optional[datetime] = None,
incremental: bool = True,
temp_directory: str = "/tmp",
debug: bool = False,
check_revision: int = 0,
max_content_size: Optional[int] = None,
):
"""Load a svn repository (either remote or local).
Args:
url: The default origin url
origin_url: Optional original url override to use as origin reference in the
archive. If not provided, "url" is used as origin.
visit_date: Optional date to override the visit date
incremental: If True, the default, starts from the last snapshot (if any).
Otherwise, starts from the initial commit of the repository.
temp_directory: The temporary directory to use as root directory for working
directory computations
debug: If true, run the loader in debug mode. At the end of the loading, the
temporary working directory is not cleaned up to ease inspection.
Defaults to false.
check_revision: The number of svn commits between checks for hash divergence
max_content_size: Default max content size allowed
"""
super().__init__(
storage=storage,
logging_class="swh.loader.svn.SvnLoader",
max_content_size=max_content_size,
)
# technical svn uri to act on svn repository
self.svn_url = url
# origin url as unique identifier for origin in swh archive
self.origin_url = origin_url if origin_url else self.svn_url
self.debug = debug
self.temp_directory = temp_directory
self.done = False
self.svnrepo = None
# Revision check is configurable
self.check_revision = check_revision
# internal state used to store swh objects
self._contents: List[Content] = []
self._skipped_contents: List[SkippedContent] = []
self._directories: List[Directory] = []
self._revisions: List[Revision] = []
self._snapshot: Optional[Snapshot] = None
# internal state, current visit
self._last_revision = None
self._visit_status = "full"
self._load_status = "uneventful"
self.visit_date = visit_date
self.incremental = incremental
self.snapshot: Optional[Snapshot] = None
# state from previous visit
self.latest_snapshot = None
self.latest_revision = None
def pre_cleanup(self):
"""Cleanup potential dangling files from prior runs (e.g. OOM killed
tasks)
"""
clean_dangling_folders(
self.temp_directory,
pattern_check=TEMPORARY_DIR_PREFIX_PATTERN,
log=self.log,
)
def cleanup(self):
"""Clean up the svn repository's working representation on disk.
"""
if not self.svnrepo: # could happen if `prepare` fails
return
if self.debug:
self.log.error(
"""NOT FOR PRODUCTION - debug flag activated
Local repository not cleaned up for investigation: %s""",
self.svnrepo.local_url.decode("utf-8"),
)
return
self.svnrepo.clean_fs()
def swh_revision_hash_tree_at_svn_revision(self, revision: int) -> bytes:
"""Compute and return the hash tree at a given svn revision.
Args:
rev: the svn revision we want to check
Returns:
The hash tree directory as bytes.
"""
assert self.svnrepo is not None
local_dirname, local_url = self.svnrepo.export_temporary(revision)
h = from_disk.Directory.from_disk(path=local_url).hash
self.svnrepo.clean_fs(local_dirname)
return h
def _latest_snapshot_revision(
self, origin_url: str,
) -> Optional[Tuple[Snapshot, Revision]]:
"""Look for latest snapshot revision and returns it if any.
Args:
origin_url: Origin identifier
previous_swh_revision: possible previous swh revision (either a dict or
revision identifier)
Returns:
Tuple of the latest Snapshot from the previous visit and its targeted
revision if any or None otherwise.
"""
storage = self.storage
latest_snapshot = snapshot_get_latest(storage, origin_url)
if not latest_snapshot:
return None
branches = latest_snapshot.branches
if not branches:
return None
branch = branches.get(DEFAULT_BRANCH)
if not branch:
return None
if branch.target_type != TargetType.REVISION:
return None
swh_id = branch.target
revision = storage.revision_get([swh_id])[0]
if not revision:
return None
return latest_snapshot, revision
def build_swh_revision(
self, rev: int, commit: Dict, dir_id: bytes, parents: Sequence[bytes]
) -> Revision:
"""Build the swh revision dictionary.
This adds:
- the `'synthetic`' flag to true
- the '`extra_headers`' containing the repository's uuid and the
svn revision number.
Args:
rev: the svn revision number
commit: the commit data: revision id, date, author, and message
dir_id: the upper tree's hash identifier
parents: the parents' identifiers
Returns:
The swh revision corresponding to the svn revision.
"""
assert self.svnrepo is not None
return converters.build_swh_revision(
rev, commit, self.svnrepo.uuid, dir_id, parents
)
def check_history_not_altered(
self, svnrepo: SvnRepo, revision_start: int, swh_rev: Revision
) -> bool:
"""Given a svn repository, check if the history was modified in between visits.
"""
revision_id = swh_rev.id
parents = swh_rev.parents
hash_data_per_revs = svnrepo.swh_hash_data_at_revision(revision_start)
rev = revision_start
commit, root_dir = list(hash_data_per_revs)[0]
dir_id = root_dir.hash
swh_revision = self.build_swh_revision(rev, commit, dir_id, parents)
swh_revision_id = swh_revision.id
return swh_revision_id == revision_id
def start_from(self) -> Tuple[int, int, Dict[int, Tuple[bytes, ...]]]:
"""Determine from where to start the loading.
Returns:
tuple (revision_start, revision_end, revision_parents)
Raises:
SvnLoaderHistoryAltered: When a hash divergence has been
detected (should not happen)
SvnLoaderUneventful: Nothing changed since last visit
"""
assert self.svnrepo is not None, "svnrepo initialized in the `prepare` method"
revision_head = self.svnrepo.head_revision()
if revision_head == 0: # empty repository case
revision_start = 0
revision_end = 0
else: # default configuration
revision_start = self.svnrepo.initial_revision()
revision_end = revision_head
revision_parents: Dict[int, Tuple[bytes, ...]] = {revision_start: ()}
# start from a previous revision if any
if self.incremental and self.latest_revision is not None:
extra_headers = dict(self.latest_revision.extra_headers)
revision_start = int(extra_headers[b"svn_revision"])
revision_parents = {
revision_start: self.latest_revision.parents,
}
self.log.debug(
"svn export --ignore-keywords %s@%s",
self.svnrepo.remote_url,
revision_start,
)
if not self.check_history_not_altered(
self.svnrepo, revision_start, self.latest_revision
):
self.log.debug(
(
"History of svn %s@%s altered. "
"A complete reloading of the repository will be performed."
),
self.svnrepo.remote_url,
revision_start,
)
revision_start = self.svnrepo.initial_revision()
# now we know history is ok, we start at next revision
revision_start = revision_start + 1
# and the parent become the latest know revision for
# that repository
revision_parents[revision_start] = (self.latest_revision.id,)
if revision_start > revision_end:
msg = "%s@%s already injected." % (self.svnrepo.remote_url, revision_end)
raise SvnLoaderUneventful(msg)
self.log.info(
"Processing revisions [%s-%s] for %s",
revision_start,
revision_end,
self.svnrepo,
)
return revision_start, revision_end, revision_parents
def _check_revision_divergence(self, rev: int, dir_id: bytes) -> None:
"""Check for hash revision computation divergence.
The Rationale behind this is that svn can trigger unknown edge cases (mixed
CRLF, svn properties, etc...). Those are not always easy to spot. Adding a
regular check will help spotting potential missing edge cases.
Args:
rev: The actual revision we are computing from
dir_id: The actual directory for the given revision
Raises
ValueError if a hash divergence is detected
"""
self.log.debug("Checking hash computations on revision %s...", rev)
checked_dir_id = self.swh_revision_hash_tree_at_svn_revision(rev)
if checked_dir_id != dir_id:
err = (
"Hash tree computation divergence detected "
"(%s != %s), stopping!"
% (hashutil.hash_to_hex(dir_id), hashutil.hash_to_hex(checked_dir_id),)
)
raise ValueError(err)
def process_svn_revisions(
self, svnrepo, revision_start, revision_end, revision_parents
) -> Iterator[
Tuple[List[Content], List[SkippedContent], List[Directory], Revision]
]:
"""Process svn revisions from revision_start to revision_end.
At each svn revision, apply new diffs and simultaneously
compute swh hashes. This yields those computed swh hashes as
a tuple (contents, directories, revision).
Note that at every `self.check_revision`, a supplementary
check takes place to check for hash-tree divergence (related
T570).
Yields:
tuple (contents, directories, revision) of dict as a
dictionary with keys, sha1_git, sha1, etc...
Raises:
ValueError in case of a hash divergence detection
"""
gen_revs = svnrepo.swh_hash_data_per_revision(revision_start, revision_end)
swh_revision = None
count = 0
for rev, nextrev, commit, new_objects, root_directory in gen_revs:
count += 1
# Send the associated contents/directories
_contents, _skipped_contents, _directories = new_objects
# compute the fs tree's checksums
dir_id = root_directory.hash
swh_revision = self.build_swh_revision(
rev, commit, dir_id, revision_parents.get(rev, ())
)
self.log.debug(
"rev: %s, swhrev: %s, dir: %s",
rev,
hashutil.hash_to_hex(swh_revision.id),
hashutil.hash_to_hex(dir_id),
)
if (
self.check_revision
and self.check_revision != 0
and count % self.check_revision == 0
):
self._check_revision_divergence(rev, dir_id)
if nextrev:
revision_parents[nextrev] = [swh_revision.id]
yield _contents, _skipped_contents, _directories, swh_revision
def prepare_origin_visit(self):
self.origin = Origin(url=self.origin_url if self.origin_url else self.svn_url)
def prepare(self):
latest_snapshot_revision = self._latest_snapshot_revision(self.origin_url)
if latest_snapshot_revision:
self.latest_snapshot, self.latest_revision = latest_snapshot_revision
local_dirname = tempfile.mkdtemp(
dir=self.temp_directory,
prefix=TEMPORARY_DIR_PREFIX_PATTERN,
suffix="-%s" % os.getpid(),
)
try:
self.svnrepo = SvnRepo(
self.svn_url, self.origin_url, local_dirname, self.max_content_size
)
except SubversionException as e:
error_msgs = [
"Unable to connect to a repository at URL",
"Unknown URL type",
]
for msg in error_msgs:
if msg in e.args[0]:
self._load_status = "uneventful"
raise NotFound(e)
raise
try:
revision_start, revision_end, revision_parents = self.start_from()
self.swh_revision_gen = self.process_svn_revisions(
self.svnrepo, revision_start, revision_end, revision_parents
)
except SvnLoaderUneventful as e:
self.log.warning(e)
if self.latest_snapshot:
self._snapshot = self.latest_snapshot
self.done = True
self._load_status = "uneventful"
except SvnLoaderHistoryAltered as e:
self.log.error(e)
self.done = True
self._visit_status = "partial"
def fetch_data(self):
"""Fetching svn revision information.
This will apply svn revision as patch on disk, and at the same
time, compute the swh hashes.
In effect, fetch_data fetches those data and compute the
necessary swh objects. It's then stored in the internal state
instance variables (initialized in `_prepare_state`).
This is up to `store_data` to actually discuss with the
storage to store those objects.
Returns:
bool: True to continue fetching data (next svn revision),
False to stop.
"""
data = None
if self.done:
return False
try:
data = next(self.swh_revision_gen)
self._load_status = "eventful"
except StopIteration:
self.done = True
self._visit_status = "full"
return False # Stopping iteration
except Exception as e: # svn:external, hash divergence, i/o error...
self.log.exception(e)
self.done = True
self._visit_status = "partial"
return False # Stopping iteration
self._contents, self._skipped_contents, self._directories, rev = data
if rev:
self._last_revision = rev
self._revisions.append(rev)
return True # next svn revision
def store_data(self):
"""We store the data accumulated in internal instance variable. If
the iteration over the svn revisions is done, we create the
snapshot and flush to storage the data.
This also resets the internal instance variable state.
"""
self.storage.skipped_content_add(self._skipped_contents)
self.storage.content_add(self._contents)
self.storage.directory_add(self._directories)
self.storage.revision_add(self._revisions)
if self.done: # finish line, snapshot!
self.snapshot = self.generate_and_load_snapshot(
revision=self._last_revision, snapshot=self._snapshot
)
self.flush()
self.loaded_snapshot_id = self.snapshot.id
# reset internal state for next iteration
self._revisions = []
def generate_and_load_snapshot(
self, revision: Optional[Revision] = None, snapshot: Optional[Snapshot] = None
) -> Snapshot:
"""Create the snapshot either from existing revision or snapshot.
Revision (supposedly new) has priority over the snapshot
(supposedly existing one).
Args:
revision (dict): Last revision seen if any (None by default)
snapshot (dict): Snapshot to use if any (None by default)
Returns:
Optional[Snapshot] The newly created snapshot
"""
if revision: # Priority to the revision
snap = Snapshot(
branches={
DEFAULT_BRANCH: SnapshotBranch(
target=revision.id, target_type=TargetType.REVISION
)
}
)
elif snapshot: # Fallback to prior snapshot
snap = snapshot
else:
raise ValueError(
"generate_and_load_snapshot called with null revision and snapshot!"
)
self.log.debug("snapshot: %s", snap)
self.storage.snapshot_add([snap])
return snap
def load_status(self):
return {
"status": self._load_status,
}
def visit_status(self):
return self._visit_status
def post_load(self, success: bool = True) -> None:
if success and self._last_revision is not None:
# check if the reconstructed filesystem for the last loaded revision is
# consistent with the one obtained with a svn export operation. If it is not
# the case, an exception will be raised to report the issue and mark the
# visit as partial
self._check_revision_divergence(
int(dict(self._last_revision.extra_headers)[b"svn_revision"]),
self._last_revision.directory,
)
class SvnLoaderFromDumpArchive(SvnLoader):
"""Uncompress an archive containing an svn dump, mount the svn dump as a local svn
repository and load that repository.
"""
def __init__(
self,
storage: StorageInterface,
url: str,
archive_path: str,
origin_url: Optional[str] = None,
incremental: bool = False,
visit_date: Optional[datetime] = None,
temp_directory: str = "/tmp",
debug: bool = False,
check_revision: int = 0,
max_content_size: Optional[int] = None,
):
super().__init__(
storage=storage,
url=url,
origin_url=origin_url,
incremental=incremental,
visit_date=visit_date,
temp_directory=temp_directory,
debug=debug,
check_revision=check_revision,
max_content_size=max_content_size,
)
self.archive_path = archive_path
self.temp_dir = None
self.repo_path = None
def prepare(self):
self.log.info("Archive to mount and load %s", self.archive_path)
self.temp_dir, self.repo_path = init_svn_repo_from_archive_dump(
self.archive_path,
prefix=TEMPORARY_DIR_PREFIX_PATTERN,
suffix="-%s" % os.getpid(),
root_dir=self.temp_directory,
)
self.svn_url = f"file://{self.repo_path}"
super().prepare()
def cleanup(self):
super().cleanup()
if self.temp_dir and os.path.exists(self.temp_dir):
self.log.debug(
"Clean up temporary directory dump %s for project %s",
self.temp_dir,
os.path.basename(self.repo_path),
)
shutil.rmtree(self.temp_dir)
class SvnLoaderFromRemoteDump(SvnLoader):
"""Create a subversion repository dump out of a remote svn repository (using the
svnrdump utility). Then, mount the repository locally and load that repository.
"""
def __init__(
self,
storage: StorageInterface,
url: str,
origin_url: Optional[str] = None,
incremental: bool = True,
visit_date: Optional[datetime] = None,
temp_directory: str = "/tmp",
debug: bool = False,
check_revision: int = 0,
max_content_size: Optional[int] = None,
):
super().__init__(
storage=storage,
url=url,
origin_url=origin_url,
incremental=incremental,
visit_date=visit_date,
temp_directory=temp_directory,
debug=debug,
check_revision=check_revision,
max_content_size=max_content_size,
)
self.temp_dir = tempfile.mkdtemp(dir=self.temp_directory)
self.repo_path = None
self.truncated_dump = False
def get_last_loaded_svn_rev(self, svn_url: str) -> int:
"""Check if the svn repository has already been visited and return the last
loaded svn revision number or -1 otherwise.
"""
origin = list(self.storage.origin_get([svn_url]))[0]
if not origin:
return -1
svn_revision = -1
try:
latest_snapshot_revision = self._latest_snapshot_revision(origin.url)
if latest_snapshot_revision:
_, latest_revision = latest_snapshot_revision
latest_revision_headers = dict(latest_revision.extra_headers)
svn_revision = int(latest_revision_headers[b"svn_revision"])
except Exception:
pass
return svn_revision
def dump_svn_revisions(self, svn_url: str, last_loaded_svn_rev: int = -1) -> str:
"""Generate a subversion dump file using the svnrdump tool. If the svnrdump
command failed somehow, the produced dump file is analyzed to determine if a
partial loading is still feasible.
Raises:
NotFound when the repository is no longer found at url
Returns:
The dump_path of the repository mounted
"""
# Build the svnrdump command line
svnrdump_cmd = ["svnrdump", "dump", svn_url]
# Launch the svnrdump command while capturing stderr as
# successfully dumped revision numbers are printed to it
dump_temp_dir = tempfile.mkdtemp(dir=self.temp_dir)
dump_name = "".join(c for c in svn_url if c.isalnum())
dump_path = "%s/%s.svndump" % (dump_temp_dir, dump_name)
stderr_lines = []
self.log.debug("Executing %s", " ".join(svnrdump_cmd))
with open(dump_path, "wb") as dump_file:
stderr_r, stderr_w = pty.openpty()
svnrdump = Popen(svnrdump_cmd, stdout=dump_file, stderr=stderr_w)
os.close(stderr_w)
stderr_stream = OutputStream(stderr_r)
readable = True
error_codes: List[str] = []
error_messages: List[str] = []
while readable:
lines, readable = stderr_stream.read_lines()
stderr_lines += lines
for line in lines:
self.log.debug(line)
match = SUBVERSION_ERROR.search(line)
if match:
error_codes.append(match.group(1))
error_messages.append(line)
svnrdump.wait()
os.close(stderr_r)
if svnrdump.returncode == 0:
return dump_path
# There was an error but it does not mean that no revisions
# can be loaded.
# Get the stderr line with latest dumped revision
last_dumped_rev = None
if len(stderr_lines) > 1:
last_dumped_rev = stderr_lines[-2]
if last_dumped_rev:
# Get the latest dumped revision number
matched_rev = re.search(".*revision ([0-9]+)", last_dumped_rev)
last_dumped_rev = int(matched_rev.group(1)) if matched_rev else -1
# Check if revisions inside the dump file can be loaded anyway
if last_dumped_rev > last_loaded_svn_rev:
self.log.debug(
(
"svnrdump did not dump all expected revisions "
"but revisions range %s:%s are available in "
"the generated dump file and will be loaded "
"into the archive."
),
last_loaded_svn_rev + 1,
last_dumped_rev,
)
# Truncate the dump file after the last successfully dumped
# revision to avoid the loading of corrupted data
self.log.debug(
(
"Truncating dump file after the last "
"successfully dumped revision (%s) to avoid "
"the loading of corrupted data"
),
last_dumped_rev,
)
with open(dump_path, "r+b") as f:
with mmap(f.fileno(), 0, access=ACCESS_WRITE) as s:
pattern = (
"Revision-number: %s" % (last_dumped_rev + 1)
).encode()
n = s.rfind(pattern)
if n != -1:
s.resize(n)
self.truncated_dump = True
return dump_path
elif last_dumped_rev != -1:
raise Exception(
(
"Last dumped subversion revision (%s) is "
"lesser than the last one loaded into the "
"archive (%s)."
)
% (last_dumped_rev, last_loaded_svn_rev)
)
if SUBVERSION_NOT_FOUND in error_codes:
raise NotFound(
f"{SUBVERSION_NOT_FOUND}: Repository never existed or disappeared"
)
raise Exception(
"An error occurred when running svnrdump and "
"no exploitable dump file has been generated.\n" + "\n".join(error_messages)
)
def prepare(self):
# First, check if previous revisions have been loaded for the
# subversion origin and get the number of the last one
last_loaded_svn_rev = self.get_last_loaded_svn_rev(self.svn_url)
# Then try to generate a dump file containing relevant svn revisions
# to load, an exception will be thrown if something wrong happened
dump_path = self.dump_svn_revisions(self.svn_url, last_loaded_svn_rev)
# Finally, mount the dump and load the repository
self.log.debug('Mounting dump file with "svnadmin load".')
_, self.repo_path = init_svn_repo_from_dump(
dump_path,
prefix=TEMPORARY_DIR_PREFIX_PATTERN,
suffix="-%s" % os.getpid(),
root_dir=self.temp_dir,
)
self.svn_url = "file://%s" % self.repo_path
super().prepare()
def cleanup(self):
super().cleanup()
if self.temp_dir and os.path.exists(self.temp_dir):
shutil.rmtree(self.temp_dir)
def visit_status(self):
if self.truncated_dump:
return "partial"
else:
return super().visit_status()

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