mirror of
https://github.com/facebook/sapling.git
synced 2024-10-07 15:27:13 +03:00
ae0a81f2c2
Summary: Move all Rust bindings to a single python extension, `bindings`. This should improve compilation time and make things simpler. Reviewed By: quark-zju Differential Revision: D13923866 fbshipit-source-id: 560592b5a6c0c4f1b836c755ef123666a1059164
134 lines
4.4 KiB
Python
134 lines
4.4 KiB
Python
# lz4revlog.py - lz4 delta compression for mercurial
|
|
#
|
|
# Copyright 2012 Facebook
|
|
#
|
|
# This software may be used and distributed according to the terms of the
|
|
# GNU General Public License version 2 or any later version.
|
|
|
|
"""store revlog deltas using lz4 compression
|
|
|
|
This extension uses the lz4 compression algorithm to store deltas,
|
|
rather than Mercurial's default of zlib compression. lz4 offers much
|
|
faster decompression than zlib, at a cost of about 30% more disk
|
|
space. The improvement in decompression speed leads to speedups in
|
|
many common operations, such as update and history traversal.
|
|
|
|
To use lz4 compression, a repository can be created from scratch or
|
|
converted from an existing repository, for example using :hg:`clone
|
|
--pull`.
|
|
|
|
The behaviour of Mercurial in an existing zlib-compressed repository
|
|
will not be affected by this extension.
|
|
|
|
To avoid use of lz4 when cloning or creating a new repository, use
|
|
:hg:`--config format.uselz4=no`.
|
|
|
|
Interop with other Mercurial repositories is generally not affected by
|
|
this extension.
|
|
"""
|
|
|
|
from __future__ import absolute_import
|
|
|
|
from edenscm.mercurial import error, extensions, localrepo, revlog, util
|
|
from edenscm.mercurial.i18n import _
|
|
from edenscm.mercurial.rust.bindings import lz4
|
|
|
|
|
|
testedwith = "3.9.1"
|
|
|
|
|
|
def replaceclass(container, classname):
|
|
"""Replace a class with another in a module, and interpose it into
|
|
the hierarchies of all loaded subclasses. This function is
|
|
intended for use as a decorator.
|
|
|
|
import mymodule
|
|
@replaceclass(mymodule, 'myclass')
|
|
class mysubclass(mymodule.myclass):
|
|
def foo(self):
|
|
f = super(mysubclass, self).foo()
|
|
return f + ' bar'
|
|
|
|
Existing instances of the class being replaced will not have their
|
|
__class__ modified, so call this function before creating any
|
|
objects of the target type.
|
|
"""
|
|
|
|
def wrap(cls):
|
|
oldcls = getattr(container, classname)
|
|
oldbases = (oldcls,)
|
|
newbases = (cls,)
|
|
for subcls in oldcls.__subclasses__():
|
|
if subcls is not cls:
|
|
assert subcls.__bases__ == oldbases
|
|
subcls.__bases__ = newbases
|
|
setattr(container, classname, cls)
|
|
return cls
|
|
|
|
return wrap
|
|
|
|
|
|
lz4compresshc = lz4.compresshc
|
|
lz4decompress = lz4.decompress
|
|
|
|
|
|
def requirements(orig, repo):
|
|
reqs = orig(repo)
|
|
if repo.ui.configbool("format", "uselz4", True):
|
|
reqs.add("lz4revlog")
|
|
return reqs
|
|
|
|
|
|
def uisetup(ui):
|
|
if util.safehasattr(localrepo, "newreporequirements"):
|
|
extensions.wrapfunction(localrepo, "newreporequirements", requirements)
|
|
else:
|
|
|
|
@replaceclass(localrepo, "localrepository")
|
|
class lz4repo(localrepo.localrepository):
|
|
def _baserequirements(self, create):
|
|
reqs = super(lz4repo, self)._baserequirements(create)
|
|
if create and self.ui.configbool("format", "uselz4", True):
|
|
reqs.append("lz4revlog")
|
|
return reqs
|
|
|
|
@replaceclass(revlog, "revlog")
|
|
class lz4revlog(revlog.revlog):
|
|
def __init__(self, opener, indexfile, **kwds):
|
|
super(lz4revlog, self).__init__(opener, indexfile, **kwds)
|
|
opts = getattr(opener, "options", None)
|
|
self._lz4 = opts and "lz4revlog" in opts
|
|
|
|
def compress(self, text):
|
|
if util.safehasattr(self, "_lz4") and self._lz4:
|
|
if not text:
|
|
return ("", text)
|
|
c = lz4compresshc(text)
|
|
if len(text) <= len(c):
|
|
if text[0] == "\0":
|
|
return ("", text)
|
|
return ("u", text)
|
|
return ("", "4" + c)
|
|
return super(lz4revlog, self).compress(text)
|
|
|
|
def decompress(self, bin):
|
|
if not bin:
|
|
return bin
|
|
t = bin[0]
|
|
if t == "\0":
|
|
return bin
|
|
if t == "4":
|
|
return lz4decompress(bin[1:])
|
|
return super(lz4revlog, self).decompress(bin)
|
|
|
|
cls = localrepo.localrepository
|
|
for reqs in "supportedformats openerreqs".split():
|
|
getattr(cls, reqs).add("lz4revlog")
|
|
if util.safehasattr(cls, "_basesupported"):
|
|
# hg >= 2.8. Since we're good at falling back to the usual revlog, we
|
|
# aren't going to bother with enabling ourselves per-repository.
|
|
cls._basesupported.add("lz4revlog")
|
|
else:
|
|
# hg <= 2.7
|
|
cls.supported.add("lz4revlog")
|