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swh/storage/algos/snapshot.py
| Show First 20 Lines • Show All 163 Lines • ▼ Show 20 Lines | for visit in iter_origin_visits(storage, origin, order=ListOrder.DESC): | ||||
| and branch.target_type == TargetType.REVISION | and branch.target_type == TargetType.REVISION | ||||
| and branch.target == revision_id | and branch.target == revision_id | ||||
| ): # snapshot found | ): # snapshot found | ||||
| yield (visit, visit_status, snapshot) | yield (visit, visit_status, snapshot) | ||||
| def snapshot_resolve_alias( | def snapshot_resolve_alias( | ||||
| storage: StorageInterface, snapshot_id: Sha1Git, alias_name: bytes | storage: StorageInterface, snapshot_id: Sha1Git, alias_name: bytes | ||||
| ) -> Optional[Tuple[List[SnapshotBranch], Optional[SnapshotBranch]]]: | ) -> Optional[SnapshotBranch]: | ||||
| """ | """ | ||||
| Resolve snapshot branch alias to its real target. | Transitively resolve snapshot branch alias to its real target, and return it; | ||||
| ie. follows every branch that is an alias, until a branch that isn't an alias | |||||
| is found. | |||||
| Args: | Args: | ||||
| storage: Storage instance | storage: Storage instance | ||||
| snapshot_id: snapshot identifier | snapshot_id: snapshot identifier | ||||
| alias_name: name of the branch alias to resolve | alias_name: name of the branch alias to resolve | ||||
| Returns: | Returns: | ||||
| A tuple whose first member is the list of followed branches until the alias | The first branch that isn't an alias, in the alias chain; or None if | ||||
| got resolved to a branch whose target type is not an alias, and second member | there is no such branch (ie. either because of a cycle alias, or a dangling | ||||
| the real targeted branch. | branch). | ||||
| If a dangling branch is encountered during the resolve process, second member of | |||||
| the tuple will be None. | |||||
| If the target type of the tuple second member is an alias, it means that | |||||
| a cycle has been detected during the resolve process. | |||||
| """ | """ | ||||
| snapshot = storage.snapshot_get_branches( | snapshot = storage.snapshot_get_branches( | ||||
| snapshot_id, branches_from=alias_name, branches_count=1 | snapshot_id, branches_from=alias_name, branches_count=1 | ||||
| ) | ) | ||||
| if snapshot is None: | if snapshot is None: | ||||
| return None | return None | ||||
| if alias_name not in snapshot["branches"]: | if alias_name not in snapshot["branches"]: | ||||
| return ([], None) | return None | ||||
| last_branch = snapshot["branches"][alias_name] | last_branch = snapshot["branches"][alias_name] | ||||
| branches = [] | |||||
| seen_aliases = {alias_name} | seen_aliases = {alias_name} | ||||
| while ( | while last_branch is not None and last_branch.target_type == TargetType.ALIAS: | ||||
| last_branch is not None | if last_branch.target in seen_aliases: | ||||
| and last_branch.target_type == TargetType.ALIAS | return None | ||||
| and last_branch.target not in seen_aliases | |||||
| ): | |||||
| branches.append(last_branch) | |||||
| alias_target = last_branch.target | alias_target = last_branch.target | ||||
| snapshot = storage.snapshot_get_branches( | snapshot = storage.snapshot_get_branches( | ||||
| snapshot_id, branches_from=alias_target, branches_count=1 | snapshot_id, branches_from=alias_target, branches_count=1 | ||||
| ) | ) | ||||
| assert snapshot is not None | assert snapshot is not None | ||||
| last_branch = snapshot["branches"].get(alias_target) | last_branch = snapshot["branches"].get(alias_target) | ||||
| seen_aliases.add(alias_target) | seen_aliases.add(alias_target) | ||||
| return (branches, last_branch) | return last_branch | ||||