Mercurial > hg
view hgext/journal.py @ 39506:b66ea3fc3a86
sparse-revlog: set max delta chain length to on thousand
The new snapshot system used in the sparse-revlog case gave us some small size
benefit so far. However its most important property is to gracefully handle
harder limit on delta chainlength.
Long delta chain has a very detrimental impact on read (and write) performance
in revlog. Being able to shorter them provide a great boost. However, shorting
delta used to result significantly lower compression ratio. The intermediate
snapshots effectively suppress most of this effect (even all in some case).
# Effect on the test repository
The repository we use for test is not "realistic" but can still show this in
action using an unreasonably low chain limit. Limiting the chain length show a
sizeable increase but stay under control: +6% for limit=15; +15% for limit=10.
Without the snapshot system the increase is significantly bigger: +45% for
limit=15; +80% for limit=10. Even slightly larger than without delta chain
limit, the resulting size is still smaller than before we started doing
snapshots.
Here is a table for comparison. *Since the repository is not branchy, the
initial sparse-revlog version does not bring much benefit compare to the
non-sparse one):
chain length limit | none | limit=15 | limit=10 |
without sparse-revlog | 62 818 987 | 112 664 615 | 131 222 574 |
without snapshot | 74 365 490 | 108 211 410 | 133 857 764 |
with snapshot | 59 230 936 | 63 002 924 | 68 415 329 |
# Effect On Real Life Repositories
The series provides significant benefits on all kind of repositories.
Using `hg debugupgraderepo -o redeltaparent --run`, we recomputed delta chain
for various repositories with different settings:
- delta chain length: unlimited or 1000 limit
- sparse-revlog: enabled or disabled
- this series: applied or not applied
We can observe multiple types of effect:
- On very branchy repositories:
* The delta chain limit as low impact on the repo size.
* Intermediate snapshot greatly reduces manifest size:
- pypy: -80%
- netbeans: -95%
* The delta chain limit is effective, without a size impact:
- netbeans average: 613 -> 282
- private #1 average: 1 068 -> 307
- On more linear repository:
* Intermediate snapshot limit the impact of delta chain limit:
- mozilla:
without the series: +360%
with the series: +25%
* The delta chain limit provides large improvement:
- mozilla's average chain length:
unlimited: 15 338
limited: 469
* Despite the chain length limit, the manifest size is reduced:
- mercurial: -25%
- mozilla: -30%
It is clear that the use of chains of intermediate snapshots provide large
benefits both in storage size and delta chains quality. We should now switch our
effort toward making sure the write performance are acceptable. Then,
`sparse-revlog` will be a suitable format for all new repository.
# Raw Statistic
* no-sparse: general delta repository not using sparse-revlog
* no-snapshot: sparse-revlog repository not using this series
* snapshot: sparse-revlog repository using this series
mercurial
Manifest Size:
limit | none | 1000
------------|-------------|------------
no-sparse | 8 021 373 | 8 199 366
no-snapshot | 8 103 561 | 8 259 719
snapshot | 6 137 116 | 6 126 433
Manifest Chain length data
limit || none || 1000 ||
value || average | max || average | max ||
------------||---------|---------||---------|---------||
no-sparse || 307 | 1456 || 279 | 1000 ||
no-snapshot || 312 | 1456 || 283 | 1000 ||
snapshot || 248 | 1208 || 241 | 1000 ||
Full Store Size
limit | none | 1000
------------|-------------|------------
no-sparse | 51 013 198 | 51 201 574
no-snapshot | 50 930 795 | 51 141 006
snapshot | 48 072 037 | 48 093 572
pypy
Manifest Size:
limit | none | 1000
------------|-------------|------------
no-sparse | 193 987 784 | 193 987 784
no-snapshot | 163 171 745 | 163 312 229
snapshot | 34 605 900 | 34 600 750
Manifest Chain length data
limit || none || 1000 ||
value || average | max || average | max ||
------------||---------|---------||---------|---------||
no-sparse || 101 | 692 || 101 | 692 ||
no-snapshot || 151 | 1307 || 148 | 1000 ||
snapshot || 128 | 1309 || 125 | 1000 ||
Full Store Size
limit | none | 1000
------------|-------------|------------
no-sparse | 495 931 473 | 495 931 473
no-snapshot | 465 441 017 | 465 581 501
snapshot | 355 467 301 | 355 472 451
Mozilla
Manifest Size:
limit | none | 1000
------------|----------------|---------------
no-sparse | 416 757 148 | 1 869 009 668
no-snapshot | 401 592 370 | 1 843 493 795
snapshot | 224 359 521 | 284 615 500
Manifest Chain length data
limit || none || 1000 ||
value || average | max || average | max ||
------------||---------|---------||---------|---------||
no-sparse || 15 333 | 58 980 || 468 | 1 000 ||
no-snapshot || 15 336 | 58 980 || 469 | 1 000 ||
snapshot || 15 338 | 58 983 || 469 | 1 000 ||
Full Store Size
limit | none | 1000
------------|----------------|---------------
no-sparse | 2 712 477 887 | 4 164 995 451
no-snapshot | 2 698 887 835 | 4 141 054 304
snapshot | 2 518 130 385 | 2 578 587 596
Netbeans
Manifest Size:
limit | none | 1000
------------|----------------|---------------
no-sparse | 4 766 794 101 | 4 870 642 687
no-snapshot | 4 334 806 082 | 4 428 681 309
snapshot | 232 659 666 | 240 330 665
Manifest Chain length data
limit || none || 1000 ||
value || average | max || average | max ||
------------||---------|---------||---------|---------||
no-sparse || 597 | 6802 || 254 | 1 000 ||
no-snapshot || 648 | 6 802 || 305 | 1 000 ||
snapshot || 613 | 6 804 || 282 | 1 000 ||
Full Store Size
limit | none | 1000
------------|----------------|---------------
no-sparse | 5 807 347 998 | 5 911 196 584
no-snapshot | 5 375 398 602 | 5 469 273 829
snapshot | 1 282 519 928 | 1 290 190 927
Private repo #1
Manifest Size:
limit | none | 1000
------------|-----------------|---------------
no-sparse | 41 389 010 840 | 41 398 162 091
no-snapshot | 9 737 319 435 | 10 223 773 150
snapshot | 744 215 807 | 747 961 822
Manifest Chain length data
limit || none || 1000 ||
value || average | max || average | max ||
------------||---------|---------||---------|---------||
no-sparse || 245 | 8 885 || 81 | 1 000 ||
no-snapshot || 1 225 | 8 885 || 336 | 1 000 ||
snapshot || 1 068 | 7 909 || 307 | 1 000 ||
Full Store Size
limit | none | 1000
------------|----------------|---------------
no-sparse | 49 646 065 126 | 49 655 216 377
no-snapshot | 17 924 862 856 | 18 411 316 571
snapshot | 9 009 024 710 | 9 012 770 725
Private repo #2
We currently have less data available for that repository.
* Before is a sparse-revlog repository without this series
* After is a sparse-revlog repository with this series + 1000 chain limit
Manifest Size:
Before: 1 531 485 040 bytes
After: 1 091 422 451 bytes
Manifest Chain:
Before: 2 218 avg; 6 575 Max
After: 442 avg; 1 000 Max
Full Store Size
Before: 15 203 955 615
after: 8 207 180 693
author | Boris Feld <boris.feld@octobus.net> |
---|---|
date | Fri, 07 Sep 2018 11:18:45 -0400 |
parents | 9954d0e2ad00 |
children | dea771e63c3c |
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# journal.py # # Copyright 2014-2016 Facebook, Inc. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """track previous positions of bookmarks (EXPERIMENTAL) This extension adds a new command: `hg journal`, which shows you where bookmarks were previously located. """ from __future__ import absolute_import import collections import errno import os import weakref from mercurial.i18n import _ from mercurial import ( bookmarks, cmdutil, dispatch, encoding, error, extensions, hg, localrepo, lock, logcmdutil, node, pycompat, registrar, util, ) from mercurial.utils import ( dateutil, procutil, stringutil, ) cmdtable = {} command = registrar.command(cmdtable) # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should # be specifying the version(s) of Mercurial they are tested with, or # leave the attribute unspecified. testedwith = 'ships-with-hg-core' # storage format version; increment when the format changes storageversion = 0 # namespaces bookmarktype = 'bookmark' wdirparenttype = 'wdirparent' # In a shared repository, what shared feature name is used # to indicate this namespace is shared with the source? sharednamespaces = { bookmarktype: hg.sharedbookmarks, } # Journal recording, register hooks and storage object def extsetup(ui): extensions.wrapfunction(dispatch, 'runcommand', runcommand) extensions.wrapfunction(bookmarks.bmstore, '_write', recordbookmarks) extensions.wrapfilecache( localrepo.localrepository, 'dirstate', wrapdirstate) extensions.wrapfunction(hg, 'postshare', wrappostshare) extensions.wrapfunction(hg, 'copystore', unsharejournal) def reposetup(ui, repo): if repo.local(): repo.journal = journalstorage(repo) repo._wlockfreeprefix.add('namejournal') dirstate, cached = localrepo.isfilecached(repo, 'dirstate') if cached: # already instantiated dirstate isn't yet marked as # "journal"-ing, even though repo.dirstate() was already # wrapped by own wrapdirstate() _setupdirstate(repo, dirstate) def runcommand(orig, lui, repo, cmd, fullargs, *args): """Track the command line options for recording in the journal""" journalstorage.recordcommand(*fullargs) return orig(lui, repo, cmd, fullargs, *args) def _setupdirstate(repo, dirstate): dirstate.journalstorage = repo.journal dirstate.addparentchangecallback('journal', recorddirstateparents) # hooks to record dirstate changes def wrapdirstate(orig, repo): """Make journal storage available to the dirstate object""" dirstate = orig(repo) if util.safehasattr(repo, 'journal'): _setupdirstate(repo, dirstate) return dirstate def recorddirstateparents(dirstate, old, new): """Records all dirstate parent changes in the journal.""" old = list(old) new = list(new) if util.safehasattr(dirstate, 'journalstorage'): # only record two hashes if there was a merge oldhashes = old[:1] if old[1] == node.nullid else old newhashes = new[:1] if new[1] == node.nullid else new dirstate.journalstorage.record( wdirparenttype, '.', oldhashes, newhashes) # hooks to record bookmark changes (both local and remote) def recordbookmarks(orig, store, fp): """Records all bookmark changes in the journal.""" repo = store._repo if util.safehasattr(repo, 'journal'): oldmarks = bookmarks.bmstore(repo) for mark, value in store.iteritems(): oldvalue = oldmarks.get(mark, node.nullid) if value != oldvalue: repo.journal.record(bookmarktype, mark, oldvalue, value) return orig(store, fp) # shared repository support def _readsharedfeatures(repo): """A set of shared features for this repository""" try: return set(repo.vfs.read('shared').splitlines()) except IOError as inst: if inst.errno != errno.ENOENT: raise return set() def _mergeentriesiter(*iterables, **kwargs): """Given a set of sorted iterables, yield the next entry in merged order Note that by default entries go from most recent to oldest. """ order = kwargs.pop(r'order', max) iterables = [iter(it) for it in iterables] # this tracks still active iterables; iterables are deleted as they are # exhausted, which is why this is a dictionary and why each entry also # stores the key. Entries are mutable so we can store the next value each # time. iterable_map = {} for key, it in enumerate(iterables): try: iterable_map[key] = [next(it), key, it] except StopIteration: # empty entry, can be ignored pass while iterable_map: value, key, it = order(iterable_map.itervalues()) yield value try: iterable_map[key][0] = next(it) except StopIteration: # this iterable is empty, remove it from consideration del iterable_map[key] def wrappostshare(orig, sourcerepo, destrepo, **kwargs): """Mark this shared working copy as sharing journal information""" with destrepo.wlock(): orig(sourcerepo, destrepo, **kwargs) with destrepo.vfs('shared', 'a') as fp: fp.write('journal\n') def unsharejournal(orig, ui, repo, repopath): """Copy shared journal entries into this repo when unsharing""" if (repo.path == repopath and repo.shared() and util.safehasattr(repo, 'journal')): sharedrepo = hg.sharedreposource(repo) sharedfeatures = _readsharedfeatures(repo) if sharedrepo and sharedfeatures > {'journal'}: # there is a shared repository and there are shared journal entries # to copy. move shared date over from source to destination but # move the local file first if repo.vfs.exists('namejournal'): journalpath = repo.vfs.join('namejournal') util.rename(journalpath, journalpath + '.bak') storage = repo.journal local = storage._open( repo.vfs, filename='namejournal.bak', _newestfirst=False) shared = ( e for e in storage._open(sharedrepo.vfs, _newestfirst=False) if sharednamespaces.get(e.namespace) in sharedfeatures) for entry in _mergeentriesiter(local, shared, order=min): storage._write(repo.vfs, entry) return orig(ui, repo, repopath) class journalentry(collections.namedtuple( u'journalentry', u'timestamp user command namespace name oldhashes newhashes')): """Individual journal entry * timestamp: a mercurial (time, timezone) tuple * user: the username that ran the command * namespace: the entry namespace, an opaque string * name: the name of the changed item, opaque string with meaning in the namespace * command: the hg command that triggered this record * oldhashes: a tuple of one or more binary hashes for the old location * newhashes: a tuple of one or more binary hashes for the new location Handles serialisation from and to the storage format. Fields are separated by newlines, hashes are written out in hex separated by commas, timestamp and timezone are separated by a space. """ @classmethod def fromstorage(cls, line): (time, user, command, namespace, name, oldhashes, newhashes) = line.split('\n') timestamp, tz = time.split() timestamp, tz = float(timestamp), int(tz) oldhashes = tuple(node.bin(hash) for hash in oldhashes.split(',')) newhashes = tuple(node.bin(hash) for hash in newhashes.split(',')) return cls( (timestamp, tz), user, command, namespace, name, oldhashes, newhashes) def __bytes__(self): """bytes representation for storage""" time = ' '.join(map(pycompat.bytestr, self.timestamp)) oldhashes = ','.join([node.hex(hash) for hash in self.oldhashes]) newhashes = ','.join([node.hex(hash) for hash in self.newhashes]) return '\n'.join(( time, self.user, self.command, self.namespace, self.name, oldhashes, newhashes)) __str__ = encoding.strmethod(__bytes__) class journalstorage(object): """Storage for journal entries Entries are divided over two files; one with entries that pertain to the local working copy *only*, and one with entries that are shared across multiple working copies when shared using the share extension. Entries are stored with NUL bytes as separators. See the journalentry class for the per-entry structure. The file format starts with an integer version, delimited by a NUL. This storage uses a dedicated lock; this makes it easier to avoid issues with adding entries that added when the regular wlock is unlocked (e.g. the dirstate). """ _currentcommand = () _lockref = None def __init__(self, repo): self.user = procutil.getuser() self.ui = repo.ui self.vfs = repo.vfs # is this working copy using a shared storage? self.sharedfeatures = self.sharedvfs = None if repo.shared(): features = _readsharedfeatures(repo) sharedrepo = hg.sharedreposource(repo) if sharedrepo is not None and 'journal' in features: self.sharedvfs = sharedrepo.vfs self.sharedfeatures = features # track the current command for recording in journal entries @property def command(self): commandstr = ' '.join( map(procutil.shellquote, journalstorage._currentcommand)) if '\n' in commandstr: # truncate multi-line commands commandstr = commandstr.partition('\n')[0] + ' ...' return commandstr @classmethod def recordcommand(cls, *fullargs): """Set the current hg arguments, stored with recorded entries""" # Set the current command on the class because we may have started # with a non-local repo (cloning for example). cls._currentcommand = fullargs def _currentlock(self, lockref): """Returns the lock if it's held, or None if it's not. (This is copied from the localrepo class) """ if lockref is None: return None l = lockref() if l is None or not l.held: return None return l def jlock(self, vfs): """Create a lock for the journal file""" if self._currentlock(self._lockref) is not None: raise error.Abort(_('journal lock does not support nesting')) desc = _('journal of %s') % vfs.base try: l = lock.lock(vfs, 'namejournal.lock', 0, desc=desc) except error.LockHeld as inst: self.ui.warn( _("waiting for lock on %s held by %r\n") % (desc, inst.locker)) # default to 600 seconds timeout l = lock.lock( vfs, 'namejournal.lock', self.ui.configint("ui", "timeout"), desc=desc) self.ui.warn(_("got lock after %s seconds\n") % l.delay) self._lockref = weakref.ref(l) return l def record(self, namespace, name, oldhashes, newhashes): """Record a new journal entry * namespace: an opaque string; this can be used to filter on the type of recorded entries. * name: the name defining this entry; for bookmarks, this is the bookmark name. Can be filtered on when retrieving entries. * oldhashes and newhashes: each a single binary hash, or a list of binary hashes. These represent the old and new position of the named item. """ if not isinstance(oldhashes, list): oldhashes = [oldhashes] if not isinstance(newhashes, list): newhashes = [newhashes] entry = journalentry( dateutil.makedate(), self.user, self.command, namespace, name, oldhashes, newhashes) vfs = self.vfs if self.sharedvfs is not None: # write to the shared repository if this feature is being # shared between working copies. if sharednamespaces.get(namespace) in self.sharedfeatures: vfs = self.sharedvfs self._write(vfs, entry) def _write(self, vfs, entry): with self.jlock(vfs): version = None # open file in amend mode to ensure it is created if missing with vfs('namejournal', mode='a+b') as f: f.seek(0, os.SEEK_SET) # Read just enough bytes to get a version number (up to 2 # digits plus separator) version = f.read(3).partition('\0')[0] if version and version != "%d" % storageversion: # different version of the storage. Exit early (and not # write anything) if this is not a version we can handle or # the file is corrupt. In future, perhaps rotate the file # instead? self.ui.warn( _("unsupported journal file version '%s'\n") % version) return if not version: # empty file, write version first f.write(("%d" % storageversion) + '\0') f.seek(0, os.SEEK_END) f.write(bytes(entry) + '\0') def filtered(self, namespace=None, name=None): """Yield all journal entries with the given namespace or name Both the namespace and the name are optional; if neither is given all entries in the journal are produced. Matching supports regular expressions by using the `re:` prefix (use `literal:` to match names or namespaces that start with `re:`) """ if namespace is not None: namespace = stringutil.stringmatcher(namespace)[-1] if name is not None: name = stringutil.stringmatcher(name)[-1] for entry in self: if namespace is not None and not namespace(entry.namespace): continue if name is not None and not name(entry.name): continue yield entry def __iter__(self): """Iterate over the storage Yields journalentry instances for each contained journal record. """ local = self._open(self.vfs) if self.sharedvfs is None: return local # iterate over both local and shared entries, but only those # shared entries that are among the currently shared features shared = ( e for e in self._open(self.sharedvfs) if sharednamespaces.get(e.namespace) in self.sharedfeatures) return _mergeentriesiter(local, shared) def _open(self, vfs, filename='namejournal', _newestfirst=True): if not vfs.exists(filename): return with vfs(filename) as f: raw = f.read() lines = raw.split('\0') version = lines and lines[0] if version != "%d" % storageversion: version = version or _('not available') raise error.Abort(_("unknown journal file version '%s'") % version) # Skip the first line, it's a version number. Normally we iterate over # these in reverse order to list newest first; only when copying across # a shared storage do we forgo reversing. lines = lines[1:] if _newestfirst: lines = reversed(lines) for line in lines: if not line: continue yield journalentry.fromstorage(line) # journal reading # log options that don't make sense for journal _ignoreopts = ('no-merges', 'graph') @command( 'journal', [ ('', 'all', None, 'show history for all names'), ('c', 'commits', None, 'show commit metadata'), ] + [opt for opt in cmdutil.logopts if opt[1] not in _ignoreopts], '[OPTION]... [BOOKMARKNAME]') def journal(ui, repo, *args, **opts): """show the previous position of bookmarks and the working copy The journal is used to see the previous commits that bookmarks and the working copy pointed to. By default the previous locations for the working copy. Passing a bookmark name will show all the previous positions of that bookmark. Use the --all switch to show previous locations for all bookmarks and the working copy; each line will then include the bookmark name, or '.' for the working copy, as well. If `name` starts with `re:`, the remainder of the name is treated as a regular expression. To match a name that actually starts with `re:`, use the prefix `literal:`. By default hg journal only shows the commit hash and the command that was running at that time. -v/--verbose will show the prior hash, the user, and the time at which it happened. Use -c/--commits to output log information on each commit hash; at this point you can use the usual `--patch`, `--git`, `--stat` and `--template` switches to alter the log output for these. `hg journal -T json` can be used to produce machine readable output. """ opts = pycompat.byteskwargs(opts) name = '.' if opts.get('all'): if args: raise error.Abort( _("You can't combine --all and filtering on a name")) name = None if args: name = args[0] fm = ui.formatter('journal', opts) if opts.get("template") != "json": if name is None: displayname = _('the working copy and bookmarks') else: displayname = "'%s'" % name ui.status(_("previous locations of %s:\n") % displayname) limit = logcmdutil.getlimit(opts) entry = None ui.pager('journal') for count, entry in enumerate(repo.journal.filtered(name=name)): if count == limit: break newhashesstr = fm.formatlist(map(fm.hexfunc, entry.newhashes), name='node', sep=',') oldhashesstr = fm.formatlist(map(fm.hexfunc, entry.oldhashes), name='node', sep=',') fm.startitem() fm.condwrite(ui.verbose, 'oldhashes', '%s -> ', oldhashesstr) fm.write('newhashes', '%s', newhashesstr) fm.condwrite(ui.verbose, 'user', ' %-8s', entry.user) fm.condwrite( opts.get('all') or name.startswith('re:'), 'name', ' %-8s', entry.name) timestring = fm.formatdate(entry.timestamp, '%Y-%m-%d %H:%M %1%2') fm.condwrite(ui.verbose, 'date', ' %s', timestring) fm.write('command', ' %s\n', entry.command) if opts.get("commits"): displayer = logcmdutil.changesetdisplayer(ui, repo, opts) for hash in entry.newhashes: try: ctx = repo[hash] displayer.show(ctx) except error.RepoLookupError as e: fm.write('repolookuperror', "%s\n\n", pycompat.bytestr(e)) displayer.close() fm.end() if entry is None: ui.status(_("no recorded locations\n"))