comparison mercurial/branchmap.py @ 51531:f85f23f1479b

branchcache: skip entries that are topological heads in the on disk file

In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.

So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.

51530:fc710c993ec9

            raise error.ProgrammingError(msg)
        try:
            filename = self._filename(repo)
            with repo.cachevfs(filename, b"w", atomictemp=True) as f:
                self._write_header(f)
                nodecount = self._write_heads(f)
            repo.ui.log(
                b'branchcache',
                b'wrote %s with %d labels and %d nodes\n',
                _branchcachedesc(repo),
                len(self._entries),

            )

    def _write_header(self, fp) -> None:
        raise NotImplementedError

    def _write_heads(self, fp) -> int:
        """write list of heads to a file

        Return the number of heads written."""
        nodecount = 0
        for label, nodes in sorted(self._entries.items()):

    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,

                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" ")

            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,

51531:f85f23f1479b

            raise error.ProgrammingError(msg)
        try:
            filename = self._filename(repo)
            with repo.cachevfs(filename, b"w", atomictemp=True) as f:
                self._write_header(f)
                nodecount = self._write_heads(repo, f)
            repo.ui.log(
                b'branchcache',
                b'wrote %s with %d labels and %d nodes\n',
                _branchcachedesc(repo),
                len(self._entries),

            )

    def _write_header(self, fp) -> None:
        raise NotImplementedError

    def _write_heads(self, repo, fp) -> int:
        """write list of heads to a file

        Return the number of heads written."""
        nodecount = 0
        for label, nodes in sorted(self._entries.items()):

    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.

    Topological heads are not included in the listing and should be dispatched
    on the right branch at read time. Obsolete topological heads should be
    ignored.
    """

    _base_filename = b"branch3"
    _default_key_hashes = (None, None)

    def _get_topo_heads(self, repo) -> List[int]:
        """returns the topological head of a repoview content up to self.tiprev"""
        cl = repo.changelog
        if self.tiprev == nullrev:
            return []
        elif self.tiprev == cl.tiprev():
            return cl.headrevs()
        else:
            # XXX passing tiprev as ceiling of cl.headrevs could be faster
            heads = cl.headrevs(cl.revs(stop=self.tiprev))
            return heads

    def _write_header(self, fp) -> None:
        cache_keys = {
            b"tip-node": hex(self.tipnode),
            b"tip-rev": b'%d' % self.tiprev,

                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')

    def _write_heads(self, repo, fp) -> int:
        """write list of heads to a file

        Return the number of heads written."""
        nodecount = 0
        topo_heads = set(self._get_topo_heads(repo))
        to_rev = repo.changelog.index.rev
        for label, nodes in sorted(self._entries.items()):
            label = encoding.fromlocal(label)
            for node in nodes:
                rev = to_rev(node)
                if rev in topo_heads:
                    continue
                if node in self._closednodes:
                    state = b'c'
                else:
                    state = b'o'
                nodecount += 1
                fp.write(b"%s %s %s\n" % (hex(node), state, label))
        return nodecount

    @classmethod
    def _load_header(cls, repo, lineiter):
        header_line = next(lineiter)
        pieces = header_line.rstrip(b'\n').split(b" ")

            else:
                msg = b"unknown cache key: %r" % k
                raise ValueError(msg)
        args["key_hashes"] = (filtered_hash, obsolete_hash)
        return args

    def _load_heads(self, repo, lineiter):
        """fully loads the branchcache by reading from the file using the line
        iterator passed"""
        super()._load_heads(repo, lineiter)
        cl = repo.changelog
        getbranchinfo = repo.revbranchcache().branchinfo
        obsrevs = obsolete.getrevs(repo, b'obsolete')
        to_node = cl.node
        touched_branch = set()
        for head in self._get_topo_heads(repo):
            if head in obsrevs:
                continue
            node = to_node(head)
            branch, closed = getbranchinfo(head)
            self._entries.setdefault(branch, []).append(node)
            if closed:
                self._closednodes.add(node)
            touched_branch.add(branch)
        to_rev = cl.index.rev
        for branch in touched_branch:
            self._entries[branch].sort(key=to_rev)

    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,