marmoute created this revision. Herald added a reviewer: indygreg. Herald added a reviewer: hg-reviewers. Herald added a subscriber: mercurial-patches.
REVISION SUMMARY The revlog docker is now storing a default compression engine. When a chunk use that compression, a dedicated mode is used in the revlog entry and we can directly route it to the right decompressor. We should probably make PLAIN and DEFAULT mode the only available mode for revlogv2, but this is something for later. REPOSITORY rHG Mercurial BRANCH default REVISION DETAIL https://phab.mercurial-scm.org/D10652 AFFECTED FILES mercurial/revlog.py mercurial/revlogutils/constants.py mercurial/revlogutils/docket.py CHANGE DETAILS diff --git a/mercurial/revlogutils/docket.py b/mercurial/revlogutils/docket.py --- a/mercurial/revlogutils/docket.py +++ b/mercurial/revlogutils/docket.py @@ -21,6 +21,7 @@ from .. import ( error, + util, ) from . import ( @@ -36,7 +37,8 @@ # * 8 bytes: pending size of index-data # * 8 bytes: size of data # * 8 bytes: pending size of data -S_HEADER = struct.Struct(constants.INDEX_HEADER.format + 'LLLL') +# * 1 bytes: default compression header +S_HEADER = struct.Struct(constants.INDEX_HEADER.format + 'LLLLc') class RevlogDocket(object): @@ -51,6 +53,7 @@ pending_index_end=0, data_end=0, pending_data_end=0, + default_compression_header=None, ): self._version_header = version_header self._read_only = bool(use_pending) @@ -71,6 +74,7 @@ else: self._index_end = self._initial_index_end self._data_end = self._initial_data_end + self.default_compression_header = default_compression_header def index_filepath(self): """file path to the current index file associated to this docket""" @@ -134,6 +138,7 @@ self._index_end, official_data_end, self._data_end, + self.default_compression_header, ) return S_HEADER.pack(*data) @@ -142,7 +147,12 @@ """given a revlog version a new docket object for the given revlog""" if (version_header & 0xFFFF) != constants.REVLOGV2: return None - docket = RevlogDocket(revlog, version_header=version_header) + comp = util.compengines[revlog._compengine].revlogheader() + docket = RevlogDocket( + revlog, + version_header=version_header, + default_compression_header=comp, + ) docket._dirty = True return docket @@ -155,6 +165,7 @@ pending_index_size = header[2] data_size = header[3] pending_data_size = header[4] + default_compression_header = header[5] docket = RevlogDocket( revlog, use_pending=use_pending, @@ -163,5 +174,6 @@ pending_index_end=pending_index_size, data_end=data_size, pending_data_end=pending_data_size, + default_compression_header=default_compression_header, ) return docket diff --git a/mercurial/revlogutils/constants.py b/mercurial/revlogutils/constants.py --- a/mercurial/revlogutils/constants.py +++ b/mercurial/revlogutils/constants.py @@ -117,6 +117,7 @@ ## chunk compression mode constants: # chunk use a compression stored "inline" at the start of the chunk itself. +COMP_MODE_DEFAULT = 1 COMP_MODE_INLINE = 2 COMP_MODE_PLAIN = 0 diff --git a/mercurial/revlog.py b/mercurial/revlog.py --- a/mercurial/revlog.py +++ b/mercurial/revlog.py @@ -35,6 +35,7 @@ from .pycompat import getattr from .revlogutils.constants import ( ALL_KINDS, + COMP_MODE_DEFAULT, COMP_MODE_INLINE, COMP_MODE_PLAIN, FEATURES_BY_VERSION, @@ -706,6 +707,15 @@ engine = util.compengines[self._compengine] return engine.revlogcompressor(self._compengineopts) + @util.propertycache + def _decompressor(self): + """the default decompressor""" + if self._docket is None: + return None + t = self._docket.default_compression_header + c = self._get_decompressor(t) + return c.decompress + def _indexfp(self): """file object for the revlog's index file""" return self.opener(self._indexfile, mode=b"r") @@ -1774,6 +1784,8 @@ data = self._getsegmentforrevs(rev, rev, df=df)[1] if compression_mode == COMP_MODE_PLAIN: return data + elif compression_mode == COMP_MODE_DEFAULT: + return self._decompressor(data) elif compression_mode == COMP_MODE_INLINE: return self.decompress(data) else: @@ -1827,6 +1839,8 @@ return [self._chunk(rev, df=df) for rev in revschunk] decomp = self.decompress + # self._decompressor might be None, but will not be used in that case + def_decomp = self._decompressor for rev in revschunk: chunkstart = start(rev) if inline: @@ -1838,6 +1852,8 @@ ladd(c) elif comp_mode == COMP_MODE_INLINE: ladd(decomp(c)) + elif comp_mode == COMP_MODE_DEFAULT: + ladd(def_decomp(c)) else: msg = 'unknown compression mode %d' msg %= comp_mode @@ -2487,8 +2503,12 @@ if not h and not d: # not data to store at all... declare them uncompressed compression_mode = COMP_MODE_PLAIN - elif not h and d[0:1] == b'\0': - compression_mode = COMP_MODE_PLAIN + elif not h: + t = d[0:1] + if t == b'\0': + compression_mode = COMP_MODE_PLAIN + elif t == self._docket.default_compression_header: + compression_mode = COMP_MODE_DEFAULT elif h == b'u': # we have a more efficient way to declare uncompressed h = b'' To: marmoute, indygreg, #hg-reviewers Cc: mercurial-patches, mercurial-devel _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
