Mercurial > hg
view mercurial/repair.py @ 37716:dfc51a482031
registrar: replace "cmdtype" with an intent-based mechanism (API)
Commands perform varied actions and repositories vary in their
capabilities.
Historically, the .hg/requires file has been used to lock out clients
lacking a requirement. But this is a very heavy-handed approach and
is typically reserved for cases where the on-disk storage format
changes and we want to prevent incompatible clients from operating on
a repo.
Outside of the .hg/requires file, we tend to deal with things like
optional, extension-provided features via checking at call sites.
We'll either have checks in core or extensions will monkeypatch
functions in core disabling incompatible features, enabling new
features, etc.
Things are somewhat tolerable today. But once we introduce alternate
storage backends with varying support for repository features and
vastly different modes of behavior, the current model will quickly
grow unwieldy. For example, the implementation of the "simple store"
required a lot of hacks to deal with stripping and verify because
various parts of core assume things are implemented a certain way.
Partial clone will require new ways of modeling file data retrieval,
because we can no longer assume that all file data is already local.
In this new world, some commands might not make any sense for certain
types of repositories.
What we need is a mechanism to affect the construction of repository
(and eventually peer) instances so the requirements/capabilities
needed for the current operation can be taken into account. "Current
operation" can almost certainly be defined by a command. So it makes
sense for commands to declare their intended actions.
This commit introduces the "intents" concept on the command registrar.
"intents" captures a set of strings that declare actions that are
anticipated to be taken, requirements the repository must possess, etc.
These intents will be passed into hg.repo(), which will pass them into
localrepository, where they can be used to influence the object being
created. Some use cases for this include:
* For read-only intents, constructing a repository object that doesn't
expose methods that can mutate the repository. Its VFS instances
don't even allow opening a file with write access.
* For read-only intents, constructing a repository object without
cache invalidation logic. If the repo never changes during its lifetime,
nothing ever needs to be invalidated and we don't need to do expensive
things like verify the changelog's hidden revisions state is accurate
every time we access repo.changelog.
* We can automatically hide commands from `hg help` when the current
repository doesn't provide that command. For example, an alternate
storage backend may not support `hg commit`, so we can hide that
command or anything else that would perform local commits.
We already kind of had an "intents" mechanism on the registrar in the
form of "cmdtype." However, it was never used. And it was limited to
a single value. We really need something that supports multiple
intents. And because intents may be defined by extensions and at this
point are advisory, I think it is best to define them in a set rather
than as separate arguments/attributes on the command.
Differential Revision: https://phab.mercurial-scm.org/D3376
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 14 Apr 2018 09:23:48 -0700 |
parents | f0b6fbea00cf |
children | 46c2b19a1263 |
line wrap: on
line source
# 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 ( hex, short, ) from . import ( bundle2, changegroup, discovery, error, exchange, obsolete, obsutil, util, ) from .utils import ( stringutil, ) def backupbundle(repo, bases, heads, node, suffix, compress=True, obsolescence=True): """create a bundle with the specified revisions as a backup""" 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)).digest() name = "%s/%s-%s-%s.hg" % (backupdir, short(node), hex(totalhash[:4]), suffix) cgversion = changegroup.localversion(repo) comp = None if cgversion != '01': bundletype = "HG20" if compress: comp = 'BZ' elif compress: bundletype = "HG10BZ" else: bundletype = "HG10UN" outgoing = discovery.outgoing(repo, missingroots=bases, missingheads=heads) contentopts = { 'cg.version': cgversion, 'obsolescence': obsolescence, 'phases': True, } return bundle2.writenewbundle(repo.ui, repo, 'strip', name, bundletype, outgoing, contentopts, 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 _collectrevlog(revlog, striprev): _, brokenset = revlog.getstrippoint(striprev) return [revlog.linkrev(r) for r in brokenset] def _collectmanifest(repo, striprev): return _collectrevlog(repo.manifestlog._revlog, striprev) def _collectbrokencsets(repo, files, striprev): """return the changesets which will be broken by the truncation""" s = set() s.update(_collectmanifest(repo, striprev)) for fname in files: s.update(_collectrevlog(repo.file(fname), striprev)) return s def strip(ui, repo, nodelist, backup=True, topic='backup'): # This function requires the caller to lock the repo, but it operates # within a transaction of its own, and thus requires there to be no current # transaction when it is called. if repo.currenttransaction() is not None: raise error.ProgrammingError('cannot strip from inside a transaction') # 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) files = _collectfiles(repo, striprev) saverevs = _collectbrokencsets(repo, files, striprev) # 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) saveheads = set(saverevs) for r in cl.revs(start=striprev + 1): if any(p in tostrip for p in cl.parentrevs(r)): tostrip.add(r) 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] stripobsidx = obsmarkers = () if repo.ui.configbool('devel', 'strip-obsmarkers'): obsmarkers = obsutil.exclusivemarkers(repo, stripbases) if obsmarkers: stripobsidx = [i for i, m in enumerate(repo.obsstore) if m in obsmarkers] # 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 = backupbundle(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)) tmpbundlefile = None if saveheads: # do not compress temporary bundle if we remove it from disk later # # We do not include obsolescence, it might re-introduce prune markers # we are trying to strip. This is harmless since the stripped markers # are already backed up and we did not touched the markers for the # saved changesets. tmpbundlefile = backupbundle(repo, savebases, saveheads, node, 'temp', compress=False, obsolescence=False) try: with repo.transaction("strip") as tr: offset = len(tr.entries) tr.startgroup() cl.strip(striprev, tr) stripmanifest(repo, striprev, tr, files) 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] with repo.svfs(file, 'a', checkambig=True) as fp: fp.truncate(troffset) if troffset == 0: repo.store.markremoved(file) deleteobsmarkers(repo.obsstore, stripobsidx) del repo.obsstore repo.invalidatevolatilesets() repo._phasecache.filterunknown(repo) if tmpbundlefile: ui.note(_("adding branch\n")) f = vfs.open(tmpbundlefile, "rb") gen = exchange.readbundle(ui, f, tmpbundlefile, vfs) if not repo.ui.verbose: # silence internal shuffling chatter repo.ui.pushbuffer() tmpbundleurl = 'bundle:' + vfs.join(tmpbundlefile) txnname = 'strip' if not isinstance(gen, bundle2.unbundle20): txnname = "strip\n%s" % util.hidepassword(tmpbundleurl) with repo.transaction(txnname) as tr: bundle2.applybundle(repo, gen, tr, source='strip', url=tmpbundleurl) if not repo.ui.verbose: repo.ui.popbuffer() f.close() with repo.transaction('repair') as tr: bmchanges = [(m, repo[newbmtarget].node()) for m in updatebm] bm.applychanges(repo, tr, bmchanges) # 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), stringutil.forcebytestr(e))) except: # re-raises if backupfile: ui.warn(_("strip failed, backup bundle stored in '%s'\n") % vfs.join(backupfile)) if tmpbundlefile: ui.warn(_("strip failed, unrecovered changes stored in '%s'\n") % vfs.join(tmpbundlefile)) ui.warn(_("(fix the problem, then recover the changesets with " "\"hg unbundle '%s'\")\n") % vfs.join(tmpbundlefile)) raise else: if tmpbundlefile: # Remove temporary bundle only if there were no exceptions vfs.unlink(tmpbundlefile) repo.destroyed() # return the backup file path (or None if 'backup' was False) so # extensions can use it return backupfile def safestriproots(ui, repo, nodes): """return list of roots of nodes where descendants are covered by nodes""" torev = repo.unfiltered().changelog.rev revs = set(torev(n) for n in nodes) # tostrip = wanted - unsafe = wanted - ancestors(orphaned) # orphaned = affected - wanted # affected = descendants(roots(wanted)) # wanted = revs tostrip = set(repo.revs('%ld-(::((roots(%ld)::)-%ld))', revs, revs, revs)) notstrip = revs - tostrip if notstrip: nodestr = ', '.join(sorted(short(repo[n].node()) for n in notstrip)) ui.warn(_('warning: orphaned descendants detected, ' 'not stripping %s\n') % nodestr) return [c.node() for c in repo.set('roots(%ld)', tostrip)] class stripcallback(object): """used as a transaction postclose callback""" def __init__(self, ui, repo, backup, topic): self.ui = ui self.repo = repo self.backup = backup self.topic = topic or 'backup' self.nodelist = [] def addnodes(self, nodes): self.nodelist.extend(nodes) def __call__(self, tr): roots = safestriproots(self.ui, self.repo, self.nodelist) if roots: strip(self.ui, self.repo, roots, self.backup, self.topic) def delayedstrip(ui, repo, nodelist, topic=None): """like strip, but works inside transaction and won't strip irreverent revs nodelist must explicitly contain all descendants. Otherwise a warning will be printed that some nodes are not stripped. Always do a backup. The last non-None "topic" will be used as the backup topic name. The default backup topic name is "backup". """ tr = repo.currenttransaction() if not tr: nodes = safestriproots(ui, repo, nodelist) return strip(ui, repo, nodes, True, topic) # transaction postclose callbacks are called in alphabet order. # use '\xff' as prefix so we are likely to be called last. callback = tr.getpostclose('\xffstrip') if callback is None: callback = stripcallback(ui, repo, True, topic) tr.addpostclose('\xffstrip', callback) if topic: callback.topic = topic callback.addnodes(nodelist) def stripmanifest(repo, striprev, tr, files): revlog = repo.manifestlog._revlog revlog.strip(striprev, tr) striptrees(repo, tr, striprev, files) def striptrees(repo, tr, striprev, files): 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.manifestlog._revlog.dirlog(dir).strip(striprev, tr) 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