comparison mercurial/branchmap.py @ 51520:fe8347b984f3

branchcache-v3: introduce a v3 format

For now the format is the very same, however we will start changing it in
future changesets.

51519:ec640dc9cebd

            # (The cache warming setup by localrepo will update the file later.)
            self.write(repo)


def branch_cache_from_file(repo) -> Optional[_LocalBranchCache]:
    """Build a branch cache from on-disk data if possible"""
    return BranchCacheV2.fromfile(repo)


def new_branch_cache(repo, *args, **kwargs):
    """Build a new branch cache from argument"""
    return BranchCacheV2(repo, *args, **kwargs)


class BranchCacheV2(_LocalBranchCache):
    """a branch cache using version 2 of the format on disk

    This field can be used to avoid changelog reads when determining if a
    branch head closes a branch or not.
    """

    _base_filename = b"branch2"


class remotebranchcache(_BaseBranchCache):
    """Branchmap info for a remote connection, should not write locally"""

51520:fe8347b984f3

            # (The cache warming setup by localrepo will update the file later.)
            self.write(repo)


def branch_cache_from_file(repo) -> Optional[_LocalBranchCache]:
    """Build a branch cache from on-disk data if possible

    Return a branch cache of the right format depending of the repository.
    """
    if repo.ui.configbool(b"experimental", b"branch-cache-v3"):
        return BranchCacheV3.fromfile(repo)
    else:
        return BranchCacheV2.fromfile(repo)


def new_branch_cache(repo, *args, **kwargs):
    """Build a new branch cache from argument

    Return a branch cache of the right format depending of the repository.
    """
    if repo.ui.configbool(b"experimental", b"branch-cache-v3"):
        return BranchCacheV3(repo, *args, **kwargs)
    else:
        return BranchCacheV2(repo, *args, **kwargs)


class BranchCacheV2(_LocalBranchCache):
    """a branch cache using version 2 of the format on disk

    This field can be used to avoid changelog reads when determining if a
    branch head closes a branch or not.
    """

    _base_filename = b"branch2"


class BranchCacheV3(_LocalBranchCache):
    """a branch cache using version 3 of the format on disk

    This version is still EXPERIMENTAL and the format is subject to changes.

    The cache is serialized on disk in the following format:

    <tip hex node> <tip rev number> [optional filtered repo hex hash]
    <branch head hex node> <open/closed state> <branch name>
    <branch head hex node> <open/closed state> <branch name>
    ...

    The first line is used to check if the cache is still valid. If the
    branch cache is for a filtered repo view, an optional third hash is
    included that hashes the hashes of all filtered and obsolete revisions.

    The open/closed state is represented by a single letter 'o' or 'c'.
    This field can be used to avoid changelog reads when determining if a
    branch head closes a branch or not.
    """

    _base_filename = b"branch3"


class remotebranchcache(_BaseBranchCache):
    """Branchmap info for a remote connection, should not write locally"""