Mercurial > hg
view hgext/share.py @ 24735:07200e3332a1
tags: extract .hgtags filenodes cache to a standalone file
Resolution of .hgtags filenodes values has historically been a
performance pain point for large repositories, where reading individual
manifests can take over 100ms. Multiplied by hundreds or even thousands
of heads and resolving .hgtags filenodes becomes a performance issue.
This patch establishes a standalone cache file holding the .hgtags
filenodes for each changeset. After this patch, the .hgtags filenode
for any particular changeset should only have to be computed once
during the lifetime of the repository.
The introduced hgtagsfnodes1 cache file is modeled after the rev branch
cache: the cache is effectively an array of entries consisting of a
changeset fragment and the filenode for a revision. The file grows in
proportion to the length of the repository (24 bytes per changeset) and
is truncated when the repository is stripped. The file is not written
unless tag info is requested and tags have changed since last time.
This patch partially addresses issue4550. Future patches will split the
"tags" cache file into per-filter files and will refactor the cache
format to not capture the .hgtags fnodes, as these are now stored in
the hgtagsfnodes1 cache. This patch is capable of standing alone. We
should not have to wait on the tags cache filter split and format
refactor for this patch to land.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 15 Apr 2015 17:42:38 -0400 |
parents | 135b23868f45 |
children | 80c5b2666a96 |
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# 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''' from mercurial.i18n import _ from mercurial import cmdutil, hg, util, extensions, bookmarks from mercurial.hg import repository, parseurl import errno cmdtable = {} command = cmdutil.command(cmdtable) testedwith = 'internal' @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, not noupdate, 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 util.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, sopener and sjoin of repo repo.unfiltered().__init__(repo.baseui, repo.root) def extsetup(ui): extensions.wrapfunction(bookmarks.bmstore, 'getbkfile', getbkfile) extensions.wrapfunction(bookmarks.bmstore, 'recordchange', recordchange) extensions.wrapfunction(bookmarks.bmstore, 'write', write) def _hassharedbookmarks(repo): """Returns whether this repo has shared bookmarks""" try: shared = repo.vfs.read('shared').splitlines() except IOError, inst: if inst.errno != errno.ENOENT: raise return False return 'bookmarks' 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 # 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) return repository(repo.ui, srcurl) def getbkfile(orig, self, repo): if _hassharedbookmarks(repo): srcrepo = _getsrcrepo(repo) if srcrepo is not None: repo = srcrepo return orig(self, 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 write(orig, self): # First write local bookmarks file in case we ever unshare orig(self) if _hassharedbookmarks(self._repo): srcrepo = _getsrcrepo(self._repo) if srcrepo is not None: self._writerepo(srcrepo)