# Copyright (C) 2016-2020 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 from collections import defaultdict from dataclasses import dataclass import datetime from io import BytesIO import logging import os import pickle import sys from typing import Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, Type import dulwich.client from dulwich.object_store import ObjectStoreGraphWalker from dulwich.pack import PackData, PackInflater from swh.model import hashutil from swh.model.model import ( BaseContent, Directory, Origin, Revision, Release, Snapshot, SnapshotBranch, TargetType, Sha1Git, ) from swh.loader.core.loader import DVCSLoader from swh.storage.algos.snapshot import snapshot_get_latest from . import converters, utils class RepoRepresentation: """Repository representation for a Software Heritage origin.""" def __init__( self, storage, base_snapshot: Optional[Snapshot] = None, ignore_history=False ): self.storage = storage self.ignore_history = ignore_history if base_snapshot and not ignore_history: self.base_snapshot: Snapshot = base_snapshot else: self.base_snapshot = Snapshot(branches={}) self.heads: Set[bytes] = set() def get_parents(self, commit: bytes) -> List[bytes]: """This method should return the list of known parents""" return [] def graph_walker(self) -> ObjectStoreGraphWalker: return ObjectStoreGraphWalker(self.heads, self.get_parents) def determine_wants(self, refs: Dict[bytes, bytes]) -> List[bytes]: """Get the list of bytehex sha1s that the git loader should fetch. This compares the remote refs sent by the server with the base snapshot provided by the loader. """ if not refs: return [] # Cache existing heads local_heads: Set[bytes] = set() for branch_name, branch in self.base_snapshot.branches.items(): if not branch or branch.target_type == TargetType.ALIAS: continue local_heads.add(hashutil.hash_to_hex(branch.target).encode()) self.heads = local_heads # Get the remote heads that we want to fetch remote_heads: Set[bytes] = set() for ref_name, ref_target in refs.items(): if utils.ignore_branch_name(ref_name): continue remote_heads.add(ref_target) return list(remote_heads - local_heads) @dataclass class FetchPackReturn: remote_refs: Dict[bytes, bytes] symbolic_refs: Dict[bytes, bytes] pack_buffer: BytesIO pack_size: int class GitLoader(DVCSLoader): """A bulk loader for a git repository""" CONFIG_BASE_FILENAME = "loader/git" ADDITIONAL_CONFIG = { "pack_size_bytes": ("int", 4 * 1024 * 1024 * 1024), } visit_type = "git" def __init__( self, url: str, base_url: Optional[str] = None, ignore_history: bool = False, repo_representation: Type[RepoRepresentation] = RepoRepresentation, config: Optional[Dict[str, Any]] = None, ): """Initialize the bulk updater. Args: repo_representation: swh's repository representation which is in charge of filtering between known and remote data. """ if config is None: config = {} super().__init__(logging_class="swh.loader.git.BulkLoader", config=config) self.origin_url = url self.base_url = base_url self.ignore_history = ignore_history self.repo_representation = repo_representation # state initialized in fetch_data self.remote_refs: Dict[bytes, bytes] = {} self.symbolic_refs: Dict[bytes, bytes] = {} def fetch_pack_from_origin( self, origin_url: str, base_snapshot: Optional[Snapshot], do_activity: Callable[[bytes], None], ) -> FetchPackReturn: """Fetch a pack from the origin""" pack_buffer = BytesIO() base_repo = self.repo_representation( storage=self.storage, base_snapshot=base_snapshot, ignore_history=self.ignore_history, ) client, path = dulwich.client.get_transport_and_path( origin_url, thin_packs=False ) size_limit = self.config["pack_size_bytes"] def do_pack(data: bytes) -> None: cur_size = pack_buffer.tell() would_write = len(data) if cur_size + would_write > size_limit: raise IOError( "Pack file too big for repository %s, " "limit is %d bytes, current size is %d, " "would write %d" % (origin_url, size_limit, cur_size, would_write) ) pack_buffer.write(data) pack_result = client.fetch_pack( path, base_repo.determine_wants, base_repo.graph_walker(), do_pack, progress=do_activity, ) remote_refs = pack_result.refs or {} symbolic_refs = pack_result.symrefs or {} pack_buffer.flush() pack_size = pack_buffer.tell() pack_buffer.seek(0) return FetchPackReturn( remote_refs=utils.filter_refs(remote_refs), symbolic_refs=utils.filter_refs(symbolic_refs), pack_buffer=pack_buffer, pack_size=pack_size, ) def list_pack( self, pack_data, pack_size ) -> Tuple[Dict[bytes, bytes], Dict[bytes, Set[bytes]]]: id_to_type = {} type_to_ids = defaultdict(set) inflater = self.get_inflater() for obj in inflater: type, id = obj.type_name, obj.id id_to_type[id] = type type_to_ids[type].add(id) return id_to_type, type_to_ids def prepare_origin_visit(self, *args, **kwargs) -> None: self.visit_date = datetime.datetime.now(tz=datetime.timezone.utc) self.origin = Origin(url=self.origin_url) def get_full_snapshot(self, origin_url) -> Optional[Snapshot]: return snapshot_get_latest(self.storage, origin_url) def prepare(self, *args, **kwargs) -> None: assert self.origin is not None prev_snapshot: Optional[Snapshot] = None if not self.ignore_history: prev_snapshot = self.get_full_snapshot(self.origin.url) if self.base_url and prev_snapshot is None: base_origin = list(self.storage.origin_get([self.base_url]))[0] if base_origin: prev_snapshot = self.get_full_snapshot(base_origin.url) if prev_snapshot is not None: self.base_snapshot = prev_snapshot else: self.base_snapshot = Snapshot(branches={}) def fetch_data(self) -> bool: assert self.origin is not None def do_progress(msg: bytes) -> None: sys.stderr.buffer.write(msg) sys.stderr.flush() fetch_info = self.fetch_pack_from_origin( self.origin.url, self.base_snapshot, do_progress ) self.pack_buffer = fetch_info.pack_buffer self.pack_size = fetch_info.pack_size self.remote_refs = fetch_info.remote_refs self.symbolic_refs = fetch_info.symbolic_refs self.log.info( "Listed %d refs for repo %s" % (len(self.remote_refs), self.origin.url), extra={ "swh_type": "git_repo_list_refs", "swh_repo": self.origin.url, "swh_num_refs": len(self.remote_refs), }, ) # We want to load the repository, walk all the objects id_to_type, type_to_ids = self.list_pack(self.pack_buffer, self.pack_size) self.id_to_type = id_to_type self.type_to_ids = type_to_ids # No more data to fetch return False def save_data(self) -> None: """Store a pack for archival""" assert isinstance(self.visit_date, datetime.datetime) write_size = 8192 pack_dir = self.get_save_data_path() pack_name = "%s.pack" % self.visit_date.isoformat() refs_name = "%s.refs" % self.visit_date.isoformat() with open(os.path.join(pack_dir, pack_name), "xb") as f: self.pack_buffer.seek(0) while True: r = self.pack_buffer.read(write_size) if not r: break f.write(r) self.pack_buffer.seek(0) with open(os.path.join(pack_dir, refs_name), "xb") as f: pickle.dump(self.remote_refs, f) def get_inflater(self) -> PackInflater: """Reset the pack buffer and get an object inflater from it""" self.pack_buffer.seek(0) return PackInflater.for_pack_data( PackData.from_file(self.pack_buffer, self.pack_size) ) def has_contents(self) -> bool: return bool(self.type_to_ids[b"blob"]) def get_content_ids(self) -> Iterable[Dict[str, Any]]: """Get the content identifiers from the git repository""" for raw_obj in self.get_inflater(): if raw_obj.type_name != b"blob": continue yield converters.dulwich_blob_to_content_id(raw_obj) def get_contents(self) -> Iterable[BaseContent]: """Format the blobs from the git repository as swh contents""" missing_contents = set( self.storage.content_missing(list(self.get_content_ids()), "sha1_git") ) for raw_obj in self.get_inflater(): if raw_obj.type_name != b"blob": continue if raw_obj.sha().digest() not in missing_contents: continue yield converters.dulwich_blob_to_content( raw_obj, max_content_size=self.max_content_size ) def has_directories(self) -> bool: return bool(self.type_to_ids[b"tree"]) def get_directory_ids(self) -> Iterable[Sha1Git]: """Get the directory identifiers from the git repository""" return (hashutil.hash_to_bytes(id.decode()) for id in self.type_to_ids[b"tree"]) def get_directories(self) -> Iterable[Directory]: """Format the trees as swh directories""" missing_dirs = set( self.storage.directory_missing(sorted(self.get_directory_ids())) ) for raw_obj in self.get_inflater(): if raw_obj.type_name != b"tree": continue if raw_obj.sha().digest() not in missing_dirs: continue yield converters.dulwich_tree_to_directory(raw_obj, log=self.log) def has_revisions(self) -> bool: return bool(self.type_to_ids[b"commit"]) def get_revision_ids(self) -> Iterable[Sha1Git]: """Get the revision identifiers from the git repository""" return ( hashutil.hash_to_bytes(id.decode()) for id in self.type_to_ids[b"commit"] ) def get_revisions(self) -> Iterable[Revision]: """Format commits as swh revisions""" missing_revs = set( self.storage.revision_missing(sorted(self.get_revision_ids())) ) for raw_obj in self.get_inflater(): if raw_obj.type_name != b"commit": continue if raw_obj.sha().digest() not in missing_revs: continue yield converters.dulwich_commit_to_revision(raw_obj, log=self.log) def has_releases(self) -> bool: return bool(self.type_to_ids[b"tag"]) def get_release_ids(self) -> Iterable[Sha1Git]: """Get the release identifiers from the git repository""" return (hashutil.hash_to_bytes(id.decode()) for id in self.type_to_ids[b"tag"]) def get_releases(self) -> Iterable[Release]: """Retrieve all the release objects from the git repository""" missing_rels = set(self.storage.release_missing(sorted(self.get_release_ids()))) for raw_obj in self.get_inflater(): if raw_obj.type_name != b"tag": continue if raw_obj.sha().digest() not in missing_rels: continue yield converters.dulwich_tag_to_release(raw_obj, log=self.log) def get_snapshot(self) -> Snapshot: """Get the snapshot for the current visit. The main complexity of this function is mapping target objects to their types, as the `refs` dictionaries returned by the git server only give us the identifiers for the target objects, and not their types. The loader itself only knows the types of the objects that it has fetched from the server (as it has parsed them while loading them to the archive). As we only fetched an increment between the previous snapshot and the current state of the server, we are missing the type information for the objects that would already have been referenced by the previous snapshot, and that the git server didn't send us. We infer the type of these objects from the previous snapshot. """ branches: Dict[bytes, Optional[SnapshotBranch]] = {} unfetched_refs: Dict[bytes, bytes] = {} # Retrieve types from the objects loaded by the current loader for ref_name, ref_object in self.remote_refs.items(): if ref_name in self.symbolic_refs: continue target = hashutil.hash_to_bytes(ref_object.decode()) object_type = self.id_to_type.get(ref_object) if object_type: branches[ref_name] = SnapshotBranch( target=target, target_type=converters.DULWICH_TARGET_TYPES[object_type], ) else: # The object pointed at by this ref was not fetched, supposedly # because it existed in the base snapshot. We record it here, # and we can get it from the base snapshot later. unfetched_refs[ref_name] = target dangling_branches = {} # Handle symbolic references as alias branches for ref_name, target in self.symbolic_refs.items(): branches[ref_name] = SnapshotBranch( target_type=TargetType.ALIAS, target=target, ) if target not in branches and target not in unfetched_refs: # This handles the case where the pointer is "dangling". # There's a chance that a further symbolic reference # override this default value, which is totally fine. dangling_branches[target] = ref_name branches[target] = None if unfetched_refs: # Handle inference of object types from the contents of the # previous snapshot unknown_objects = {} base_snapshot_reverse_branches = { branch.target: branch for branch in self.base_snapshot.branches.values() if branch and branch.target_type != TargetType.ALIAS } for ref_name, target in unfetched_refs.items(): branch = base_snapshot_reverse_branches.get(target) branches[ref_name] = branch if not branch: unknown_objects[ref_name] = target if unknown_objects: # This object was referenced by the server; We did not fetch # it, and we do not know it from the previous snapshot. This is # likely a bug in the loader. raise RuntimeError( "Unknown objects referenced by remote refs: %s" % ( ", ".join( f"{name.decode()}: {hashutil.hash_to_hex(obj)}" for name, obj in unknown_objects.items() ) ) ) utils.warn_dangling_branches( branches, dangling_branches, self.log, self.origin_url ) self.snapshot = Snapshot(branches=branches) return self.snapshot def get_fetch_history_result(self) -> Dict[str, int]: return { "contents": len(self.type_to_ids[b"blob"]), "directories": len(self.type_to_ids[b"tree"]), "revisions": len(self.type_to_ids[b"commit"]), "releases": len(self.type_to_ids[b"tag"]), } def load_status(self) -> Dict[str, Any]: """The load was eventful if the current snapshot is different to the one we retrieved at the beginning of the run""" eventful = False if self.base_snapshot and self.snapshot: eventful = self.snapshot.id != self.base_snapshot.id elif self.snapshot: eventful = bool(self.snapshot.branches) return {"status": ("eventful" if eventful else "uneventful")} if __name__ == "__main__": import click logging.basicConfig( level=logging.DEBUG, format="%(asctime)s %(process)d %(message)s" ) @click.command() @click.option("--origin-url", help="Origin url", required=True) @click.option("--base-url", default=None, help="Optional Base url") @click.option( "--ignore-history/--no-ignore-history", help="Ignore the repository history", default=False, ) def main(origin_url: str, base_url: str, ignore_history: bool) -> Dict[str, Any]: loader = GitLoader( origin_url, base_url=base_url, ignore_history=ignore_history, ) return loader.load() main()