revlog: implement changelogv2 packing and unpacking in C
This introduces a C implementation of changelogv2 records packing and unpacking
operations matching the pure Python counterpart, similarly to what we already
have for revlogv1 and revlogv2.
This is also necessary to access changelogv2 record fields from future Rust
code without going through the Python part, which would annihilate any
performance benefit.
Differential Revision: https://phab.mercurial-scm.org/D12178
# logexchange.py
#
# Copyright 2017 Augie Fackler <raf@durin42.com>
# Copyright 2017 Sean Farley <sean@farley.io>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
from .node import hex
from . import (
pycompat,
util,
vfs as vfsmod,
)
from .utils import (
urlutil,
)
# directory name in .hg/ in which remotenames files will be present
remotenamedir = b'logexchange'
def readremotenamefile(repo, filename):
"""
reads a file from .hg/logexchange/ directory and yields it's content
filename: the file to be read
yield a tuple (node, remotepath, name)
"""
vfs = vfsmod.vfs(repo.vfs.join(remotenamedir))
if not vfs.exists(filename):
return
f = vfs(filename)
lineno = 0
for line in f:
line = line.strip()
if not line:
continue
# contains the version number
if lineno == 0:
lineno += 1
try:
node, remote, rname = line.split(b'\0')
yield node, remote, rname
except ValueError:
pass
f.close()
def readremotenames(repo):
"""
read the details about the remotenames stored in .hg/logexchange/ and
yields a tuple (node, remotepath, name). It does not yields information
about whether an entry yielded is branch or bookmark. To get that
information, call the respective functions.
"""
for bmentry in readremotenamefile(repo, b'bookmarks'):
yield bmentry
for branchentry in readremotenamefile(repo, b'branches'):
yield branchentry
def writeremotenamefile(repo, remotepath, names, nametype):
vfs = vfsmod.vfs(repo.vfs.join(remotenamedir))
f = vfs(nametype, b'w', atomictemp=True)
# write the storage version info on top of file
# version '0' represents the very initial version of the storage format
f.write(b'0\n\n')
olddata = set(readremotenamefile(repo, nametype))
# re-save the data from a different remote than this one.
for node, oldpath, rname in sorted(olddata):
if oldpath != remotepath:
f.write(b'%s\0%s\0%s\n' % (node, oldpath, rname))
for name, node in sorted(pycompat.iteritems(names)):
if nametype == b"branches":
for n in node:
f.write(b'%s\0%s\0%s\n' % (n, remotepath, name))
elif nametype == b"bookmarks":
if node:
f.write(b'%s\0%s\0%s\n' % (node, remotepath, name))
f.close()
def saveremotenames(repo, remotepath, branches=None, bookmarks=None):
"""
save remotenames i.e. remotebookmarks and remotebranches in their
respective files under ".hg/logexchange/" directory.
"""
wlock = repo.wlock()
try:
if bookmarks:
writeremotenamefile(repo, remotepath, bookmarks, b'bookmarks')
if branches:
writeremotenamefile(repo, remotepath, branches, b'branches')
finally:
wlock.release()
def activepath(repo, remote):
"""returns remote path"""
# is the remote a local peer
local = remote.local()
# determine the remote path from the repo, if possible; else just
# use the string given to us
rpath = remote
if local:
rpath = util.pconvert(remote._repo.root)
elif not isinstance(remote, bytes):
rpath = remote._url
# represent the remotepath with user defined path name if exists
for path, url in repo.ui.configitems(b'paths'):
# remove auth info from user defined url
noauthurl = urlutil.removeauth(url)
# Standardize on unix style paths, otherwise some {remotenames} end up
# being an absolute path on Windows.
url = util.pconvert(bytes(url))
noauthurl = util.pconvert(noauthurl)
if url == rpath or noauthurl == rpath:
rpath = path
break
return rpath
def pullremotenames(localrepo, remoterepo):
"""
pulls bookmarks and branches information of the remote repo during a
pull or clone operation.
localrepo is our local repository
remoterepo is the peer instance
"""
remotepath = activepath(localrepo, remoterepo)
with remoterepo.commandexecutor() as e:
bookmarks = e.callcommand(
b'listkeys',
{
b'namespace': b'bookmarks',
},
).result()
# on a push, we don't want to keep obsolete heads since
# they won't show up as heads on the next pull, so we
# remove them here otherwise we would require the user
# to issue a pull to refresh the storage
bmap = {}
repo = localrepo.unfiltered()
with remoterepo.commandexecutor() as e:
branchmap = e.callcommand(b'branchmap', {}).result()
for branch, nodes in pycompat.iteritems(branchmap):
bmap[branch] = []
for node in nodes:
if node in repo and not repo[node].obsolete():
bmap[branch].append(hex(node))
saveremotenames(localrepo, remotepath, bmap, bookmarks)