Mercurial > hg
view mercurial/subrepoutil.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 | b94fecf4cd8c |
children | 876494fd967d |
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# subrepoutil.py - sub-repository operations and substate handling # # Copyright 2009-2010 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. from __future__ import absolute_import import errno import os import posixpath import re from .i18n import _ from . import ( config, error, filemerge, pathutil, phases, util, ) from .utils import ( stringutil, ) nullstate = ('', '', 'empty') def state(ctx, ui): """return a state dict, mapping subrepo paths configured in .hgsub to tuple: (source from .hgsub, revision from .hgsubstate, kind (key in types dict)) """ p = config.config() repo = ctx.repo() def read(f, sections=None, remap=None): if f in ctx: try: data = ctx[f].data() except IOError as err: if err.errno != errno.ENOENT: raise # handle missing subrepo spec files as removed ui.warn(_("warning: subrepo spec file \'%s\' not found\n") % repo.pathto(f)) return p.parse(f, data, sections, remap, read) else: raise error.Abort(_("subrepo spec file \'%s\' not found") % repo.pathto(f)) if '.hgsub' in ctx: read('.hgsub') for path, src in ui.configitems('subpaths'): p.set('subpaths', path, src, ui.configsource('subpaths', path)) rev = {} if '.hgsubstate' in ctx: try: for i, l in enumerate(ctx['.hgsubstate'].data().splitlines()): l = l.lstrip() if not l: continue try: revision, path = l.split(" ", 1) except ValueError: raise error.Abort(_("invalid subrepository revision " "specifier in \'%s\' line %d") % (repo.pathto('.hgsubstate'), (i + 1))) rev[path] = revision except IOError as err: if err.errno != errno.ENOENT: raise def remap(src): for pattern, repl in p.items('subpaths'): # Turn r'C:\foo\bar' into r'C:\\foo\\bar' since re.sub # does a string decode. repl = stringutil.escapestr(repl) # However, we still want to allow back references to go # through unharmed, so we turn r'\\1' into r'\1'. Again, # extra escapes are needed because re.sub string decodes. repl = re.sub(br'\\\\([0-9]+)', br'\\\1', repl) try: src = re.sub(pattern, repl, src, 1) except re.error as e: raise error.Abort(_("bad subrepository pattern in %s: %s") % (p.source('subpaths', pattern), stringutil.forcebytestr(e))) return src state = {} for path, src in p[''].items(): kind = 'hg' if src.startswith('['): if ']' not in src: raise error.Abort(_('missing ] in subrepository source')) kind, src = src.split(']', 1) kind = kind[1:] src = src.lstrip() # strip any extra whitespace after ']' if not util.url(src).isabs(): parent = _abssource(repo, abort=False) if parent: parent = util.url(parent) parent.path = posixpath.join(parent.path or '', src) parent.path = posixpath.normpath(parent.path) joined = bytes(parent) # Remap the full joined path and use it if it changes, # else remap the original source. remapped = remap(joined) if remapped == joined: src = remap(src) else: src = remapped src = remap(src) state[util.pconvert(path)] = (src.strip(), rev.get(path, ''), kind) return state def writestate(repo, state): """rewrite .hgsubstate in (outer) repo with these subrepo states""" lines = ['%s %s\n' % (state[s][1], s) for s in sorted(state) if state[s][1] != nullstate[1]] repo.wwrite('.hgsubstate', ''.join(lines), '') def submerge(repo, wctx, mctx, actx, overwrite, labels=None): """delegated from merge.applyupdates: merging of .hgsubstate file in working context, merging context and ancestor context""" if mctx == actx: # backwards? actx = wctx.p1() s1 = wctx.substate s2 = mctx.substate sa = actx.substate sm = {} repo.ui.debug("subrepo merge %s %s %s\n" % (wctx, mctx, actx)) def debug(s, msg, r=""): if r: r = "%s:%s:%s" % r repo.ui.debug(" subrepo %s: %s %s\n" % (s, msg, r)) promptssrc = filemerge.partextras(labels) for s, l in sorted(s1.iteritems()): prompts = None a = sa.get(s, nullstate) ld = l # local state with possible dirty flag for compares if wctx.sub(s).dirty(): ld = (l[0], l[1] + "+") if wctx == actx: # overwrite a = ld prompts = promptssrc.copy() prompts['s'] = s if s in s2: r = s2[s] if ld == r or r == a: # no change or local is newer sm[s] = l continue elif ld == a: # other side changed debug(s, "other changed, get", r) wctx.sub(s).get(r, overwrite) sm[s] = r elif ld[0] != r[0]: # sources differ prompts['lo'] = l[0] prompts['ro'] = r[0] if repo.ui.promptchoice( _(' subrepository sources for %(s)s differ\n' 'use (l)ocal%(l)s source (%(lo)s)' ' or (r)emote%(o)s source (%(ro)s)?' '$$ &Local $$ &Remote') % prompts, 0): debug(s, "prompt changed, get", r) wctx.sub(s).get(r, overwrite) sm[s] = r elif ld[1] == a[1]: # local side is unchanged debug(s, "other side changed, get", r) wctx.sub(s).get(r, overwrite) sm[s] = r else: debug(s, "both sides changed") srepo = wctx.sub(s) prompts['sl'] = srepo.shortid(l[1]) prompts['sr'] = srepo.shortid(r[1]) option = repo.ui.promptchoice( _(' subrepository %(s)s diverged (local revision: %(sl)s, ' 'remote revision: %(sr)s)\n' '(M)erge, keep (l)ocal%(l)s or keep (r)emote%(o)s?' '$$ &Merge $$ &Local $$ &Remote') % prompts, 0) if option == 0: wctx.sub(s).merge(r) sm[s] = l debug(s, "merge with", r) elif option == 1: sm[s] = l debug(s, "keep local subrepo revision", l) else: wctx.sub(s).get(r, overwrite) sm[s] = r debug(s, "get remote subrepo revision", r) elif ld == a: # remote removed, local unchanged debug(s, "remote removed, remove") wctx.sub(s).remove() elif a == nullstate: # not present in remote or ancestor debug(s, "local added, keep") sm[s] = l continue else: if repo.ui.promptchoice( _(' local%(l)s changed subrepository %(s)s' ' which remote%(o)s removed\n' 'use (c)hanged version or (d)elete?' '$$ &Changed $$ &Delete') % prompts, 0): debug(s, "prompt remove") wctx.sub(s).remove() for s, r in sorted(s2.items()): prompts = None if s in s1: continue elif s not in sa: debug(s, "remote added, get", r) mctx.sub(s).get(r) sm[s] = r elif r != sa[s]: prompts = promptssrc.copy() prompts['s'] = s if repo.ui.promptchoice( _(' remote%(o)s changed subrepository %(s)s' ' which local%(l)s removed\n' 'use (c)hanged version or (d)elete?' '$$ &Changed $$ &Delete') % prompts, 0) == 0: debug(s, "prompt recreate", r) mctx.sub(s).get(r) sm[s] = r # record merged .hgsubstate writestate(repo, sm) return sm def precommit(ui, wctx, status, match, force=False): """Calculate .hgsubstate changes that should be applied before committing Returns (subs, commitsubs, newstate) where - subs: changed subrepos (including dirty ones) - commitsubs: dirty subrepos which the caller needs to commit recursively - newstate: new state dict which the caller must write to .hgsubstate This also updates the given status argument. """ subs = [] commitsubs = set() newstate = wctx.substate.copy() # only manage subrepos and .hgsubstate if .hgsub is present if '.hgsub' in wctx: # we'll decide whether to track this ourselves, thanks for c in status.modified, status.added, status.removed: if '.hgsubstate' in c: c.remove('.hgsubstate') # compare current state to last committed state # build new substate based on last committed state oldstate = wctx.p1().substate for s in sorted(newstate.keys()): if not match(s): # ignore working copy, use old state if present if s in oldstate: newstate[s] = oldstate[s] continue if not force: raise error.Abort( _("commit with new subrepo %s excluded") % s) dirtyreason = wctx.sub(s).dirtyreason(True) if dirtyreason: if not ui.configbool('ui', 'commitsubrepos'): raise error.Abort(dirtyreason, hint=_("use --subrepos for recursive commit")) subs.append(s) commitsubs.add(s) else: bs = wctx.sub(s).basestate() newstate[s] = (newstate[s][0], bs, newstate[s][2]) if oldstate.get(s, (None, None, None))[1] != bs: subs.append(s) # check for removed subrepos for p in wctx.parents(): r = [s for s in p.substate if s not in newstate] subs += [s for s in r if match(s)] if subs: if (not match('.hgsub') and '.hgsub' in (wctx.modified() + wctx.added())): raise error.Abort(_("can't commit subrepos without .hgsub")) status.modified.insert(0, '.hgsubstate') elif '.hgsub' in status.removed: # clean up .hgsubstate when .hgsub is removed if ('.hgsubstate' in wctx and '.hgsubstate' not in (status.modified + status.added + status.removed)): status.removed.insert(0, '.hgsubstate') return subs, commitsubs, newstate def reporelpath(repo): """return path to this (sub)repo as seen from outermost repo""" parent = repo while util.safehasattr(parent, '_subparent'): parent = parent._subparent return repo.root[len(pathutil.normasprefix(parent.root)):] def subrelpath(sub): """return path to this subrepo as seen from outermost repo""" return sub._relpath def _abssource(repo, push=False, abort=True): """return pull/push path of repo - either based on parent repo .hgsub info or on the top repo config. Abort or return None if no source found.""" if util.safehasattr(repo, '_subparent'): source = util.url(repo._subsource) if source.isabs(): return bytes(source) source.path = posixpath.normpath(source.path) parent = _abssource(repo._subparent, push, abort=False) if parent: parent = util.url(util.pconvert(parent)) parent.path = posixpath.join(parent.path or '', source.path) parent.path = posixpath.normpath(parent.path) return bytes(parent) else: # recursion reached top repo path = None if util.safehasattr(repo, '_subtoppath'): path = repo._subtoppath elif push and repo.ui.config('paths', 'default-push'): path = repo.ui.config('paths', 'default-push') elif repo.ui.config('paths', 'default'): path = repo.ui.config('paths', 'default') elif repo.shared(): # chop off the .hg component to get the default path form. This has # already run through vfsmod.vfs(..., realpath=True), so it doesn't # have problems with 'C:' return os.path.dirname(repo.sharedpath) if path: # issue5770: 'C:\' and 'C:' are not equivalent paths. The former is # as expected: an absolute path to the root of the C: drive. The # latter is a relative path, and works like so: # # C:\>cd C:\some\path # C:\>D: # D:\>python -c "import os; print os.path.abspath('C:')" # C:\some\path # # D:\>python -c "import os; print os.path.abspath('C:relative')" # C:\some\path\relative if util.hasdriveletter(path): if len(path) == 2 or path[2:3] not in br'\/': path = os.path.abspath(path) return path if abort: raise error.Abort(_("default path for subrepository not found")) def newcommitphase(ui, ctx): commitphase = phases.newcommitphase(ui) substate = getattr(ctx, "substate", None) if not substate: return commitphase check = ui.config('phases', 'checksubrepos') if check not in ('ignore', 'follow', 'abort'): raise error.Abort(_('invalid phases.checksubrepos configuration: %s') % (check)) if check == 'ignore': return commitphase maxphase = phases.public maxsub = None for s in sorted(substate): sub = ctx.sub(s) subphase = sub.phase(substate[s][1]) if maxphase < subphase: maxphase = subphase maxsub = s if commitphase < maxphase: if check == 'abort': raise error.Abort(_("can't commit in %s phase" " conflicting %s from subrepository %s") % (phases.phasenames[commitphase], phases.phasenames[maxphase], maxsub)) ui.warn(_("warning: changes are committed in" " %s phase from subrepository %s\n") % (phases.phasenames[maxphase], maxsub)) return maxphase return commitphase