comparison mercurial/branchmap.py @ 51529:4141d12de073

branchcache: store filtered hash and obsolete hash independently for V3

This will avoid the bug covered in tests/test-branches-obsolete.t when we stop
storing all heads explicitly in V3.

51528:88b0e07dd2cd

    The first line is used to check if the cache is still valid. It is a series
    of key value pair. The following key are recognized:

    - tip-rev: the rev-num of the tip-most revision seen by this cache
    - tip-node: the node-id of the tip-most revision sen by this cache
    - filtered-hash: the hash of all filtered and obsolete revisions (before
                     tip-rev) ignored by this cache.

    The tip-rev is used to know how far behind the value in the file are
    compared to the current repository state.

    The tip-node and filtered-hash are used to detect if this cache can be used
    for this repository state at all.

    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"

    def _write_header(self, fp) -> None:
        cache_keys = {
            b"tip-node": hex(self.tipnode),
            b"tip-rev": b'%d' % self.tiprev,
        }
        if self.key_hashes:
            cache_keys[b"filtered-hash"] = hex(self.key_hashes[0])
        pieces = (b"%s=%s" % i for i in sorted(cache_keys.items()))
        fp.write(b" ".join(pieces) + b'\n')

    @classmethod
    def _load_header(cls, repo, lineiter):
        header_line = next(lineiter)
        pieces = header_line.rstrip(b'\n').split(b" ")
        cache_keys = dict(p.split(b'=', 1) for p in pieces)

        args = {}
        for k, v in cache_keys.items():
            if k == b"tip-rev":
                args["tiprev"] = int(v)
            elif k == b"tip-node":
                args["tipnode"] = bin(v)
            elif k == b"filtered-hash":
                args["key_hashes"] = (bin(v),)
            else:
                msg = b"unknown cache key: %r" % k
                raise ValueError(msg)
        return args

    def _compute_key_hashes(self, repo) -> Tuple[bytes]:
        """return the cache key hashes that match this repoview state"""
        filtered_hash = scmutil.combined_filtered_and_obsolete_hash(
            repo,
            self.tiprev,
            needobsolete=True,
        )
        if filtered_hash is None:
            return cast(Tuple[bytes], ())
        else:
            return (filtered_hash,)


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

51529:4141d12de073

    The first line is used to check if the cache is still valid. It is a series
    of key value pair. The following key are recognized:

    - tip-rev: the rev-num of the tip-most revision seen by this cache
    - tip-node: the node-id of the tip-most revision sen by this cache
    - filtered-hash: the hash of all filtered revisions (before tip-rev)
                     ignored by this cache.
    - obsolete-hash: the hash of all non-filtered obsolete revisions (before
                     tip-rev) ignored by this cache.

    The tip-rev is used to know how far behind the value in the file are
    compared to the current repository state.

    The tip-node, filtered-hash and obsolete-hash are used to detect if this
    cache can be used for this repository state at all.

    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"
    _default_key_hashes = (None, None)

    def _write_header(self, fp) -> None:
        cache_keys = {
            b"tip-node": hex(self.tipnode),
            b"tip-rev": b'%d' % self.tiprev,
        }
        if self.key_hashes:
            if self.key_hashes[0] is not None:
                cache_keys[b"filtered-hash"] = hex(self.key_hashes[0])
            if self.key_hashes[1] is not None:
                cache_keys[b"obsolete-hash"] = hex(self.key_hashes[1])
        pieces = (b"%s=%s" % i for i in sorted(cache_keys.items()))
        fp.write(b" ".join(pieces) + b'\n')

    @classmethod
    def _load_header(cls, repo, lineiter):
        header_line = next(lineiter)
        pieces = header_line.rstrip(b'\n').split(b" ")
        cache_keys = dict(p.split(b'=', 1) for p in pieces)

        args = {}
        filtered_hash = None
        obsolete_hash = None
        for k, v in cache_keys.items():
            if k == b"tip-rev":
                args["tiprev"] = int(v)
            elif k == b"tip-node":
                args["tipnode"] = bin(v)
            elif k == b"filtered-hash":
                filtered_hash = bin(v)
            elif k == b"obsolete-hash":
                obsolete_hash = bin(v)
            else:
                msg = b"unknown cache key: %r" % k
                raise ValueError(msg)
        args["key_hashes"] = (filtered_hash, obsolete_hash)
        return args

    def _compute_key_hashes(self, repo) -> Tuple[bytes]:
        """return the cache key hashes that match this repoview state"""
        return scmutil.filtered_and_obsolete_hash(
            repo,
            self.tiprev,
        )


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