# Copyright (C) 2018-2022 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
from typing import List, Optional, Tuple, Union
from swh.model.model import Snapshot, SnapshotBranch, SnapshotTargetType
from swh.model.swhids import CoreSWHID, ObjectType
from swh.storage.algos.origin import origin_get_latest_visit_status
from swh.storage.algos.snapshot import snapshot_get_all_branches
from swh.storage.interface import PartialBranches, StorageInterface
[docs]
def get_head_swhid(storage: StorageInterface, origin_url: str) -> Optional[CoreSWHID]:
"""Returns the SWHID of the head revision or release of an origin"""
visit_status = origin_get_latest_visit_status(
storage, origin_url, allowed_statuses=["full"], require_snapshot=True
)
if not visit_status:
return None
assert visit_status.snapshot is not None
if visit_status.type == "ftp":
# We need to fetch all branches in order to find the largest one
snapshot = snapshot_get_all_branches(storage, visit_status.snapshot)
if snapshot is None:
return None
return _try_get_ftp_head(storage, snapshot)
else:
# Peak into the snapshot, without fetching too many refs.
# If the snapshot is small, this gets all of it in a single request.
# If the snapshot is large, we will query specific branches as we need them.
partial_branches = storage.snapshot_get_branches(
visit_status.snapshot, branches_count=100
)
if partial_branches is None:
# Snapshot does not exist
return None
return _try_get_head_generic(storage, partial_branches)
_archive_filename_re = re.compile(
rb"^"
rb"(?P<pkgname>.*)[-_]"
rb"(?P<version>[0-9]+(\.[0-9])*)"
rb"(?P<preversion>[-+][a-zA-Z0-9.~]+?)?"
rb"(?P<extension>(\.[a-zA-Z0-9]+)+)"
rb"$"
)
def _parse_version(filename: bytes) -> Tuple[Union[float, int, str], ...]:
"""Extracts the release version from an archive filename,
to get an ordering whose maximum is likely to be the last
version of the software
>>> _parse_version(b'foo')
(-inf,)
>>> _parse_version(b'foo.tar.gz')
(-inf,)
>>> _parse_version(b'gnu-hello-0.0.1.tar.gz')
(0, 0, 1, 0)
>>> _parse_version(b'gnu-hello-0.0.1-beta2.tar.gz')
(0, 0, 1, -1, 'beta2')
>>> _parse_version(b'gnu-hello-0.0.1+foobar.tar.gz')
(0, 0, 1, 1, 'foobar')
"""
res = _archive_filename_re.match(filename)
if res is None:
return (float("-infinity"),)
version: List[Union[float, int, str]] = [
int(n) for n in res.group("version").decode().split(".")
]
if res.group("preversion") is None:
version.append(0)
else:
preversion = res.group("preversion").decode()
if preversion.startswith("-"):
version.append(-1)
version.append(preversion[1:])
elif preversion.startswith("+"):
version.append(1)
version.append(preversion[1:])
else:
assert False, res.group("preversion")
return tuple(version)
def _try_get_ftp_head(
storage: StorageInterface, snapshot: Snapshot
) -> Optional[CoreSWHID]:
archive_names = list(snapshot.branches)
max_archive_name = max(archive_names, key=_parse_version)
return _try_resolve_target(
storage,
{"id": snapshot.id, "branches": dict(snapshot.branches), "next_branch": None},
branch_name=max_archive_name,
)
def _try_get_head_generic(
storage: StorageInterface, partial_branches: PartialBranches
) -> Optional[CoreSWHID]:
# Works on 'deposit', 'pypi', and VCSs.
return _try_resolve_target(
storage, partial_branches, branch_name=b"HEAD"
) or _try_resolve_target(storage, partial_branches, branch_name=b"master")
def _get_branch(
storage: StorageInterface, partial_branches: PartialBranches, branch_name: bytes
) -> Optional[SnapshotBranch]:
"""Given a ``branch_name``, gets it from ``partial_branches`` if present,
and fetches it from the storage otherwise."""
if branch_name in partial_branches["branches"]:
return partial_branches["branches"][branch_name]
elif partial_branches["next_branch"] is not None:
# Branch is not in `partial_branches`, and `partial_branches` indeed partial
res = storage.snapshot_get_branches(
partial_branches["id"], branches_from=branch_name, branches_count=1
)
assert res is not None, "Snapshot does not exist anymore"
return res["branches"].get(branch_name)
else:
# Branch is not in `partial_branches`, but `partial_branches` is the full
# list of branches, which means it is a dangling reference.
return None
def _try_resolve_target(
storage: StorageInterface, partial_branches: PartialBranches, branch_name: bytes
) -> Optional[CoreSWHID]:
try:
branch = _get_branch(storage, partial_branches, branch_name)
if branch is None:
return None
while branch.target_type == SnapshotTargetType.ALIAS:
branch = _get_branch(storage, partial_branches, branch.target)
if branch is None:
return None
if branch.target_type == SnapshotTargetType.REVISION:
return CoreSWHID(object_type=ObjectType.REVISION, object_id=branch.target)
elif branch.target_type == SnapshotTargetType.CONTENT:
return None # TODO
elif branch.target_type == SnapshotTargetType.DIRECTORY:
return None # TODO
elif branch.target_type == SnapshotTargetType.RELEASE:
return CoreSWHID(object_type=ObjectType.RELEASE, object_id=branch.target)
else:
assert False, branch
except KeyError:
return None
