Mercurial > hg
view mercurial/repair.py @ 29847:9a9629b9416c stable
bundle2: fail faster when interrupted
Before this patch, bundle2 application attempted to consume remaining
bundle2 part data when the process is interrupted (SIGINT) or when
sys.exit is called (translated into a SystemExit exception). This
meant that if one of these occurred when applying a say 1 GB
changegroup bundle2 part being downloaded over a network, it may take
Mercurial *several minutes* to terminate after a SIGINT because the
process is waiting on the network to stream megabytes of data. This is
not a great user experience and a regression from bundle1. Furthermore,
many process supervisors tend to only give processes a finite amount of
time to exit after delivering SIGINT: if processes take too long to
self-terminate, a SIGKILL is issued and Mercurial has no opportunity to
clean up. This would mean orphaned locks and transactions. Not good.
This patch changes the bundle2 application behavior to fail faster
when an interrupt or system exit is requested. It does so by not
catching BaseException (which includes KeyboardInterrupt and
SystemExit) and by explicitly checking for these conditions in
yet another handler which would also seek to the end of the current
bundle2 part on failure.
The end result of this patch is that SIGINT is now reacted to
significantly faster: the active transaction is rolled back
immediately without waiting for incoming bundle2 data to be consumed.
This restores the pre-bundle2 behavior and makes Mercurial treat
signals with the urgency they deserve.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 25 Aug 2016 19:53:14 -0700 |
parents | 87c184c9bfef |
children | d1c3721d184c |
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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 import hashlib 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 = hashlib.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) if 'treemanifest' in repo.requirements: # safe but unnecessary # otherwise for unencoded, encoded, size in repo.store.datafiles(): if (unencoded.startswith('meta/') and unencoded.endswith('00manifest.i')): dir = unencoded[5:-12] repo.dirlog(dir).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