zstd: vendor python-zstandard 0.7.0
Commit 3054ae3a66112970a091d3939fee32c2d0c1a23e from
https://github.com/indygreg/python-zstandard is imported without
modifications (other than removing unwanted files).
The vendored zstd library within has been upgraded from 1.1.2 to
1.1.3. This version introduced new APIs for threads, thread
pools, multi-threaded compression, and a new dictionary
builder (COVER). These features are not yet used by
python-zstandard (or Mercurial for that matter). However,
that will likely change in the next python-zstandard release
(and I think there are opportunities for Mercurial to take
advantage of the multi-threaded APIs).
Relevant to Mercurial, the CFFI bindings are now fully
implemented. This means zstd should "just work" with PyPy
(although I haven't tried). The python-zstandard test suite also
runs all tests against both the C extension and CFFI bindings to
ensure feature parity.
There is also a "decompress_content_dict_chain()" API. This was
derived from discussions with Yann Collet on list about alternate
ways of encoding delta chains.
The change most relevant to Mercurial is a performance enhancement in
the simple decompression API to reuse a data structure across
operations. This makes decompression of multiple inputs significantly
faster. (This scenario occurs when reading revlog delta chains, for
example.)
Using python-zstandard's bench.py to measure the performance
difference...
On changelog chunks in the mozilla-unified repo:
decompress discrete decompress() reuse zctx
1.262243 wall; 1.260000 CPU; 1.260000 user; 0.000000 sys 170.43 MB/s (best of 3)
0.949106 wall; 0.950000 CPU; 0.950000 user; 0.000000 sys 226.66 MB/s (best of 4)
decompress discrete dict decompress() reuse zctx
0.692170 wall; 0.690000 CPU; 0.690000 user; 0.000000 sys 310.80 MB/s (best of 5)
0.437088 wall; 0.440000 CPU; 0.440000 user; 0.000000 sys 492.17 MB/s (best of 7)
On manifest chunks in the mozilla-unified repo:
decompress discrete decompress() reuse zctx
1.367284 wall; 1.370000 CPU; 1.370000 user; 0.000000 sys 274.01 MB/s (best of 3)
1.086831 wall; 1.080000 CPU; 1.080000 user; 0.000000 sys 344.72 MB/s (best of 3)
decompress discrete dict decompress() reuse zctx
0.993272 wall; 0.990000 CPU; 0.990000 user; 0.000000 sys 377.19 MB/s (best of 3)
0.678651 wall; 0.680000 CPU; 0.680000 user; 0.000000 sys 552.06 MB/s (best of 5)
That should make reads on zstd revlogs a bit faster ;)
# no-check-commit
# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''share a common history between several working directories
Automatic Pooled Storage for Clones
-----------------------------------
When this extension is active, :hg:`clone` can be configured to
automatically share/pool storage across multiple clones. This
mode effectively converts :hg:`clone` to :hg:`clone` + :hg:`share`.
The benefit of using this mode is the automatic management of
store paths and intelligent pooling of related repositories.
The following ``share.`` config options influence this feature:
``share.pool``
Filesystem path where shared repository data will be stored. When
defined, :hg:`clone` will automatically use shared repository
storage instead of creating a store inside each clone.
``share.poolnaming``
How directory names in ``share.pool`` are constructed.
"identity" means the name is derived from the first changeset in the
repository. In this mode, different remotes share storage if their
root/initial changeset is identical. In this mode, the local shared
repository is an aggregate of all encountered remote repositories.
"remote" means the name is derived from the source repository's
path or URL. In this mode, storage is only shared if the path or URL
requested in the :hg:`clone` command matches exactly to a repository
that was cloned before.
The default naming mode is "identity."
'''
from __future__ import absolute_import
import errno
from mercurial.i18n import _
from mercurial import (
bookmarks,
cmdutil,
commands,
error,
extensions,
hg,
util,
)
repository = hg.repository
parseurl = hg.parseurl
cmdtable = {}
command = cmdutil.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'
@command('share',
[('U', 'noupdate', None, _('do not create a working directory')),
('B', 'bookmarks', None, _('also share bookmarks'))],
_('[-U] [-B] SOURCE [DEST]'),
norepo=True)
def share(ui, source, dest=None, noupdate=False, bookmarks=False):
"""create a new shared repository
Initialize a new repository and working directory that shares its
history (and optionally bookmarks) with another repository.
.. note::
using rollback or extensions that destroy/modify history (mq,
rebase, etc.) can cause considerable confusion with shared
clones. In particular, if two shared clones are both updated to
the same changeset, and one of them destroys that changeset
with rollback, the other clone will suddenly stop working: all
operations will fail with "abort: working directory has unknown
parent". The only known workaround is to use debugsetparents on
the broken clone to reset it to a changeset that still exists.
"""
return hg.share(ui, source, dest=dest, update=not noupdate,
bookmarks=bookmarks)
@command('unshare', [], '')
def unshare(ui, repo):
"""convert a shared repository to a normal one
Copy the store data to the repo and remove the sharedpath data.
"""
if not repo.shared():
raise error.Abort(_("this is not a shared repo"))
destlock = lock = None
lock = repo.lock()
try:
# we use locks here because if we race with commit, we
# can end up with extra data in the cloned revlogs that's
# not pointed to by changesets, thus causing verify to
# fail
destlock = hg.copystore(ui, repo, repo.path)
sharefile = repo.join('sharedpath')
util.rename(sharefile, sharefile + '.old')
repo.requirements.discard('sharedpath')
repo._writerequirements()
finally:
destlock and destlock.release()
lock and lock.release()
# update store, spath, svfs and sjoin of repo
repo.unfiltered().__init__(repo.baseui, repo.root)
# Wrap clone command to pass auto share options.
def clone(orig, ui, source, *args, **opts):
pool = ui.config('share', 'pool', None)
if pool:
pool = util.expandpath(pool)
opts['shareopts'] = dict(
pool=pool,
mode=ui.config('share', 'poolnaming', 'identity'),
)
return orig(ui, source, *args, **opts)
def extsetup(ui):
extensions.wrapfunction(bookmarks, '_getbkfile', getbkfile)
extensions.wrapfunction(bookmarks.bmstore, 'recordchange', recordchange)
extensions.wrapfunction(bookmarks.bmstore, '_writerepo', writerepo)
extensions.wrapcommand(commands.table, 'clone', clone)
def _hassharedbookmarks(repo):
"""Returns whether this repo has shared bookmarks"""
try:
shared = repo.vfs.read('shared').splitlines()
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
return False
return hg.sharedbookmarks in shared
def _getsrcrepo(repo):
"""
Returns the source repository object for a given shared repository.
If repo is not a shared repository, return None.
"""
if repo.sharedpath == repo.path:
return None
if util.safehasattr(repo, 'srcrepo') and repo.srcrepo:
return repo.srcrepo
# the sharedpath always ends in the .hg; we want the path to the repo
source = repo.vfs.split(repo.sharedpath)[0]
srcurl, branches = parseurl(source)
srcrepo = repository(repo.ui, srcurl)
repo.srcrepo = srcrepo
return srcrepo
def getbkfile(orig, repo):
if _hassharedbookmarks(repo):
srcrepo = _getsrcrepo(repo)
if srcrepo is not None:
repo = srcrepo
return orig(repo)
def recordchange(orig, self, tr):
# Continue with write to local bookmarks file as usual
orig(self, tr)
if _hassharedbookmarks(self._repo):
srcrepo = _getsrcrepo(self._repo)
if srcrepo is not None:
category = 'share-bookmarks'
tr.addpostclose(category, lambda tr: self._writerepo(srcrepo))
def writerepo(orig, self, repo):
# First write local bookmarks file in case we ever unshare
orig(self, repo)
if _hassharedbookmarks(self._repo):
srcrepo = _getsrcrepo(self._repo)
if srcrepo is not None:
orig(self, srcrepo)