Mercurial > hg
view mercurial/repair.py @ 29304:5e32852fa4bd
revset: make filteredset.__nonzero__ respect the order of the filteredset
This fix allows __nonzero__ to respect the direction of iteration of the
whole filteredset. Here's the case when it matters. Imagine that we have a
very large repository and we want to execute a command like:
$ hg log --rev '(tip:0) and user(ikostia)' --limit 1
(we want to get the latest commit by me).
Mercurial will evaluate a filteredset lazy data structure, an
instance of the filteredset class, which will know that it has to iterate
in a descending order (isdescending() will return True if called). This
means that when some code iterates over the instance of this filteredset,
the 'and user(ikostia)' condition will be first checked on the latest
revision, then on the second latest and so on, allowing Mercurial to
print matches as it founds them. However, cmdutil.getgraphlogrevs
contains the following code:
revs = _logrevs(repo, opts)
if not revs:
return revset.baseset(), None, None
The "not revs" expression is evaluated by calling filteredset.__nonzero__,
which in its current implementation will try to iterate the filteredset
in ascending order until it finds a revision that matches the 'and user(..'
condition. If the condition is only true on late revisions, a lot of
useless iterations will be done. These iterations could be avoided if
__nonzero__ followed the order of the filteredset, which in my opinion
is a sensible thing to do here.
The problem gets even worse when instead of 'user(ikostia)' some more
expensive check is performed, like grepping the commit diff.
I tested this fix on a very large repo where tip is my commit and my very
first commit comes fairly late in the revision history. Results of timing
of the above command on that very large repo.
-with my fix:
real 0m1.795s
user 0m1.657s
sys 0m0.135s
-without my fix:
real 1m29.245s
user 1m28.223s
sys 0m0.929s
I understand that this is a very specific kind of problem that presents
itself very rarely, only on very big repositories and with expensive
checks and so on. But I don't see any disadvantages to this kind of fix
either.
author | Kostia Balytskyi <ikostia@fb.com> |
---|---|
date | Thu, 02 Jun 2016 22:39:01 +0100 |
parents | bf7b8157c483 |
children | 0d83ad967bf8 |
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# repair.py - functions for repository repair for mercurial # # Copyright 2005, 2006 Chris Mason <mason@suse.com> # Copyright 2007 Matt Mackall # # 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 import errno from .i18n import _ from .node import short from . import ( bundle2, changegroup, error, exchange, obsolete, util, ) def _bundle(repo, bases, heads, node, suffix, compress=True): """create a bundle with the specified revisions as a backup""" cgversion = changegroup.safeversion(repo) cg = changegroup.changegroupsubset(repo, bases, heads, 'strip', version=cgversion) backupdir = "strip-backup" vfs = repo.vfs if not vfs.isdir(backupdir): vfs.mkdir(backupdir) # Include a hash of all the nodes in the filename for uniqueness allcommits = repo.set('%ln::%ln', bases, heads) allhashes = sorted(c.hex() for c in allcommits) totalhash = util.sha1(''.join(allhashes)).hexdigest() name = "%s/%s-%s-%s.hg" % (backupdir, short(node), totalhash[:8], suffix) comp = None if cgversion != '01': bundletype = "HG20" if compress: comp = 'BZ' elif compress: bundletype = "HG10BZ" else: bundletype = "HG10UN" return bundle2.writebundle(repo.ui, cg, name, bundletype, vfs, compression=comp) def _collectfiles(repo, striprev): """find out the filelogs affected by the strip""" files = set() for x in xrange(striprev, len(repo)): files.update(repo[x].files()) return sorted(files) def _collectbrokencsets(repo, files, striprev): """return the changesets which will be broken by the truncation""" s = set() def collectone(revlog): _, brokenset = revlog.getstrippoint(striprev) s.update([revlog.linkrev(r) for r in brokenset]) collectone(repo.manifest) for fname in files: collectone(repo.file(fname)) return s def strip(ui, repo, nodelist, backup=True, topic='backup'): # This function operates within a transaction of its own, but does # not take any lock on the repo. # Simple way to maintain backwards compatibility for this # argument. if backup in ['none', 'strip']: backup = False repo = repo.unfiltered() repo.destroying() cl = repo.changelog # TODO handle undo of merge sets if isinstance(nodelist, str): nodelist = [nodelist] striplist = [cl.rev(node) for node in nodelist] striprev = min(striplist) # Some revisions with rev > striprev may not be descendants of striprev. # We have to find these revisions and put them in a bundle, so that # we can restore them after the truncations. # To create the bundle we use repo.changegroupsubset which requires # the list of heads and bases of the set of interesting revisions. # (head = revision in the set that has no descendant in the set; # base = revision in the set that has no ancestor in the set) tostrip = set(striplist) for rev in striplist: for desc in cl.descendants([rev]): tostrip.add(desc) files = _collectfiles(repo, striprev) saverevs = _collectbrokencsets(repo, files, striprev) # compute heads saveheads = set(saverevs) for r in xrange(striprev + 1, len(cl)): if r not in tostrip: saverevs.add(r) saveheads.difference_update(cl.parentrevs(r)) saveheads.add(r) saveheads = [cl.node(r) for r in saveheads] # compute base nodes if saverevs: descendants = set(cl.descendants(saverevs)) saverevs.difference_update(descendants) savebases = [cl.node(r) for r in saverevs] stripbases = [cl.node(r) for r in tostrip] # For a set s, max(parents(s) - s) is the same as max(heads(::s - s)), but # is much faster newbmtarget = repo.revs('max(parents(%ld) - (%ld))', tostrip, tostrip) if newbmtarget: newbmtarget = repo[newbmtarget.first()].node() else: newbmtarget = '.' bm = repo._bookmarks updatebm = [] for m in bm: rev = repo[bm[m]].rev() if rev in tostrip: updatebm.append(m) # create a changegroup for all the branches we need to keep backupfile = None vfs = repo.vfs node = nodelist[-1] if backup: backupfile = _bundle(repo, stripbases, cl.heads(), node, topic) repo.ui.status(_("saved backup bundle to %s\n") % vfs.join(backupfile)) repo.ui.log("backupbundle", "saved backup bundle to %s\n", vfs.join(backupfile)) if saveheads or savebases: # do not compress partial bundle if we remove it from disk later chgrpfile = _bundle(repo, savebases, saveheads, node, 'temp', compress=False) mfst = repo.manifest curtr = repo.currenttransaction() if curtr is not None: del curtr # avoid carrying reference to transaction for nothing msg = _('programming error: cannot strip from inside a transaction') raise error.Abort(msg, hint=_('contact your extension maintainer')) try: with repo.transaction("strip") as tr: offset = len(tr.entries) tr.startgroup() cl.strip(striprev, tr) mfst.strip(striprev, tr) for fn in files: repo.file(fn).strip(striprev, tr) tr.endgroup() for i in xrange(offset, len(tr.entries)): file, troffset, ignore = tr.entries[i] repo.svfs(file, 'a').truncate(troffset) if troffset == 0: repo.store.markremoved(file) if saveheads or savebases: ui.note(_("adding branch\n")) f = vfs.open(chgrpfile, "rb") gen = exchange.readbundle(ui, f, chgrpfile, vfs) if not repo.ui.verbose: # silence internal shuffling chatter repo.ui.pushbuffer() if isinstance(gen, bundle2.unbundle20): with repo.transaction('strip') as tr: tr.hookargs = {'source': 'strip', 'url': 'bundle:' + vfs.join(chgrpfile)} bundle2.applybundle(repo, gen, tr, source='strip', url='bundle:' + vfs.join(chgrpfile)) else: gen.apply(repo, 'strip', 'bundle:' + vfs.join(chgrpfile), True) if not repo.ui.verbose: repo.ui.popbuffer() f.close() repo._phasecache.invalidate() for m in updatebm: bm[m] = repo[newbmtarget].node() lock = tr = None try: lock = repo.lock() tr = repo.transaction('repair') bm.recordchange(tr) tr.close() finally: tr.release() lock.release() # remove undo files for undovfs, undofile in repo.undofiles(): try: undovfs.unlink(undofile) except OSError as e: if e.errno != errno.ENOENT: ui.warn(_('error removing %s: %s\n') % (undovfs.join(undofile), str(e))) except: # re-raises if backupfile: ui.warn(_("strip failed, full bundle stored in '%s'\n") % vfs.join(backupfile)) elif saveheads: ui.warn(_("strip failed, partial bundle stored in '%s'\n") % vfs.join(chgrpfile)) raise else: if saveheads or savebases: # Remove partial backup only if there were no exceptions vfs.unlink(chgrpfile) repo.destroyed() def rebuildfncache(ui, repo): """Rebuilds the fncache file from repo history. Missing entries will be added. Extra entries will be removed. """ repo = repo.unfiltered() if 'fncache' not in repo.requirements: ui.warn(_('(not rebuilding fncache because repository does not ' 'support fncache)\n')) return with repo.lock(): fnc = repo.store.fncache # Trigger load of fncache. if 'irrelevant' in fnc: pass oldentries = set(fnc.entries) newentries = set() seenfiles = set() repolen = len(repo) for rev in repo: ui.progress(_('rebuilding'), rev, total=repolen, unit=_('changesets')) ctx = repo[rev] for f in ctx.files(): # This is to minimize I/O. if f in seenfiles: continue seenfiles.add(f) i = 'data/%s.i' % f d = 'data/%s.d' % f if repo.store._exists(i): newentries.add(i) if repo.store._exists(d): newentries.add(d) ui.progress(_('rebuilding'), None) if 'treemanifest' in repo.requirements: # safe but unnecessary otherwise for dir in util.dirs(seenfiles): i = 'meta/%s/00manifest.i' % dir d = 'meta/%s/00manifest.d' % dir if repo.store._exists(i): newentries.add(i) if repo.store._exists(d): newentries.add(d) addcount = len(newentries - oldentries) removecount = len(oldentries - newentries) for p in sorted(oldentries - newentries): ui.write(_('removing %s\n') % p) for p in sorted(newentries - oldentries): ui.write(_('adding %s\n') % p) if addcount or removecount: ui.write(_('%d items added, %d removed from fncache\n') % (addcount, removecount)) fnc.entries = newentries fnc._dirty = True with repo.transaction('fncache') as tr: fnc.write(tr) else: ui.write(_('fncache already up to date\n')) def stripbmrevset(repo, mark): """ The revset to strip when strip is called with -B mark Needs to live here so extensions can use it and wrap it even when strip is not enabled or not present on a box. """ return repo.revs("ancestors(bookmark(%s)) - " "ancestors(head() and not bookmark(%s)) - " "ancestors(bookmark() and not bookmark(%s))", mark, mark, mark) def deleteobsmarkers(obsstore, indices): """Delete some obsmarkers from obsstore and return how many were deleted 'indices' is a list of ints which are the indices of the markers to be deleted. Every invocation of this function completely rewrites the obsstore file, skipping the markers we want to be removed. The new temporary file is created, remaining markers are written there and on .close() this file gets atomically renamed to obsstore, thus guaranteeing consistency.""" if not indices: # we don't want to rewrite the obsstore with the same content return left = [] current = obsstore._all n = 0 for i, m in enumerate(current): if i in indices: n += 1 continue left.append(m) newobsstorefile = obsstore.svfs('obsstore', 'w', atomictemp=True) for bytes in obsolete.encodemarkers(left, True, obsstore._version): newobsstorefile.write(bytes) newobsstorefile.close() return n