Mercurial > hg
view contrib/synthrepo.py @ 42044:bb271ec2fbfb
compression: introduce a `storage.revlog.zstd.level` configuration
This option control the zstd compression level used when compressing revlog
chunk. The usage of zstd for revlog compression has not graduated from
experimental yet, but we intend to fix that soon.
The option name for the compression level is more straight forward to pick, so
this changesets comes first. Having a dedicated option for each compression
engine is useful because they don't support the same range of values.
I ran the same measurement as for the zlib compression level (in the parent
changesets). The variation in repository size is stay mostly in the same (small)
range. The "read/write" performance see smallish variation, but are overall much
better than zlib. Write performance show the same tend of having better write
performance for when reaching high-end compression.
Again, we don't intend to change the default zstd compression level (currently:
3) in this series. However this is worth investigating in the future.
The Performance comparison of zlib vs zstd is quite impressive. The repository
size stay in the same range, but the performance are much better in all
situations.
Comparison summary
==================
We are looking at:
- performance range for zlib
- performance range for zstd
- comparison of default zstd (level-3) to default zlib (level 6)
- comparison of the slowest zstd time to the fastest zlib time
Read performance:
-----------------
| zlib | zstd | cmp | f2s
mercurial | 0.170159 - 0.189219 | 0.144127 - 0.149624 | 80% | 88%
pypy | 2.679217 - 2.768691 | 1.532317 - 1.705044 | 60% | 63%
netbeans | 122.477027 - 141.620281 | 72.996346 - 89.731560 | 58% | 73%
mozilla | 147.867662 - 170.572118 | 91.700995 - 105.853099 | 56% | 71%
Write performance:
------------------
| zlib | zstd | cmp | f2s
mercurial | 53.250304 - 56.2936129 | 40.877025 - 45.677286 | 75% | 86%
pypy | 460.721984 - 476.589918 | 270.545409 - 301.002219 | 63% | 65%
netbeans | 520.560316 - 715.930400 | 370.356311 - 428.329652 | 55% | 82%
mozilla | 739.803002 - 987.056093 | 505.152906 - 591.930683 | 57% | 80%
Raw data
--------
repo alg lvl .hg/store size 00manifest.d read write
mercurial zlib 1 49,402,813 5,963,475 0.170159 53.250304
mercurial zlib 6 47,197,397 5,875,730 0.182820 56.264320
mercurial zlib 9 47,121,596 5,849,781 0.189219 56.293612
mercurial zstd 1 49,737,084 5,966,355 0.144127 40.877025
mercurial zstd 3 48,961,867 5,895,208 0.146376 42.268142
mercurial zstd 5 48,200,592 5,938,676 0.149624 43.162875
mercurial zstd 10 47,833,520 5,913,353 0.145185 44.012489
mercurial zstd 15 47,314,604 5,728,679 0.147686 45.677286
mercurial zstd 20 47,330,502 5,830,539 0.145789 45.025407
mercurial zstd 22 47,330,076 5,830,539 0.143996 44.690460
pypy zlib 1 370,830,572 28,462,425 2.679217 460.721984
pypy zlib 6 340,112,317 27,648,747 2.768691 467.537158
pypy zlib 9 338,360,736 27,639,003 2.763495 476.589918
pypy zstd 1 362,377,479 27,916,214 1.532317 270.545409
pypy zstd 3 354,137,693 27,905,988 1.686718 294.951509
pypy zstd 5 342,640,043 27,655,774 1.705044 301.002219
pypy zstd 10 334,224,327 27,164,493 1.567287 285.186239
pypy zstd 15 329,000,363 26,645,965 1.637729 299.561332
pypy zstd 20 324,534,039 26,199,547 1.526813 302.149827
pypy zstd 22 324,530,595 26,198,932 1.525718 307.821218
netbeans zlib 1 1,281,847,810 165,495,457 122.477027 520.560316
netbeans zlib 6 1,205,284,353 159,161,207 139.876147 715.930400
netbeans zlib 9 1,197,135,671 155,034,586 141.620281 678.297064
netbeans zstd 1 1,259,581,737 160,840,613 72.996346 370.356311
netbeans zstd 3 1,232,978,122 157,691,551 81.622317 396.733087
netbeans zstd 5 1,208,034,075 160,246,880 83.080549 364.342626
netbeans zstd 10 1,188,624,176 156,083,417 79.323935 403.594602
netbeans zstd 15 1,176,973,589 153,859,477 89.731560 428.329652
netbeans zstd 20 1,162,958,258 151,147,535 82.842667 392.335349
netbeans zstd 22 1,162,707,029 151,150,220 82.565695 402.840655
mozilla zlib 1 2,775,497,186 298,527,987 147.867662 751.263721
mozilla zlib 6 2,596,856,420 286,597,671 170.572118 987.056093
mozilla zlib 9 2,587,542,494 287,018,264 163.622338 739.803002
mozilla zstd 1 2,723,159,348 286,617,532 91.700995 570.042751
mozilla zstd 3 2,665,055,001 286,152,013 95.240155 561.412805
mozilla zstd 5 2,607,819,817 288,060,030 101.978048 505.152906
mozilla zstd 10 2,558,761,085 283,967,648 104.113481 497.771202
mozilla zstd 15 2,526,216,060 275,581,300 105.853099 591.930683
mozilla zstd 20 2,485,114,806 266,478,859 95.268795 576.515389
mozilla zstd 22 2,484,869,080 266,456,505 94.429282 572.785537
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Wed, 27 Mar 2019 18:35:59 +0100 |
parents | 2ff8994ac71d |
children | c07812bdd568 |
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# synthrepo.py - repo synthesis # # Copyright 2012 Facebook # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. '''synthesize structurally interesting change history This extension is useful for creating a repository with properties that are statistically similar to an existing repository. During analysis, a simple probability table is constructed from the history of an existing repository. During synthesis, these properties are reconstructed. Properties that are analyzed and synthesized include the following: - Lines added or removed when an existing file is modified - Number and sizes of files added - Number of files removed - Line lengths - Topological distance to parent changeset(s) - Probability of a commit being a merge - Probability of a newly added file being added to a new directory - Interarrival time, and time zone, of commits - Number of files in each directory A few obvious properties that are not currently handled realistically: - Merges are treated as regular commits with two parents, which is not realistic - Modifications are not treated as operations on hunks of lines, but as insertions and deletions of randomly chosen single lines - Committer ID (always random) - Executability of files - Symlinks and binary files are ignored ''' from __future__ import absolute_import import bisect import collections import itertools import json import os import random import sys import time from mercurial.i18n import _ from mercurial.node import ( nullid, nullrev, short, ) from mercurial import ( context, diffutil, error, hg, patch, registrar, scmutil, ) from mercurial.utils import ( dateutil, ) # 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' cmdtable = {} command = registrar.command(cmdtable) newfile = {'new fi', 'rename', 'copy f', 'copy t'} def zerodict(): return collections.defaultdict(lambda: 0) def roundto(x, k): if x > k * 2: return int(round(x / float(k)) * k) return int(round(x)) def parsegitdiff(lines): filename, mar, lineadd, lineremove = None, None, zerodict(), 0 binary = False for line in lines: start = line[:6] if start == 'diff -': if filename: yield filename, mar, lineadd, lineremove, binary mar, lineadd, lineremove, binary = 'm', zerodict(), 0, False filename = patch.gitre.match(line).group(1) elif start in newfile: mar = 'a' elif start == 'GIT bi': binary = True elif start == 'delete': mar = 'r' elif start: s = start[0] if s == '-' and not line.startswith('--- '): lineremove += 1 elif s == '+' and not line.startswith('+++ '): lineadd[roundto(len(line) - 1, 5)] += 1 if filename: yield filename, mar, lineadd, lineremove, binary @command('analyze', [('o', 'output', '', _('write output to given file'), _('FILE')), ('r', 'rev', [], _('analyze specified revisions'), _('REV'))], _('hg analyze'), optionalrepo=True) def analyze(ui, repo, *revs, **opts): '''create a simple model of a repository to use for later synthesis This command examines every changeset in the given range (or all of history if none are specified) and creates a simple statistical model of the history of the repository. It also measures the directory structure of the repository as checked out. The model is written out to a JSON file, and can be used by :hg:`synthesize` to create or augment a repository with synthetic commits that have a structure that is statistically similar to the analyzed repository. ''' root = repo.root if not root.endswith(os.path.sep): root += os.path.sep revs = list(revs) revs.extend(opts['rev']) if not revs: revs = [':'] output = opts['output'] if not output: output = os.path.basename(root) + '.json' if output == '-': fp = sys.stdout else: fp = open(output, 'w') # Always obtain file counts of each directory in the given root directory. def onerror(e): ui.warn(_('error walking directory structure: %s\n') % e) dirs = {} rootprefixlen = len(root) for dirpath, dirnames, filenames in os.walk(root, onerror=onerror): dirpathfromroot = dirpath[rootprefixlen:] dirs[dirpathfromroot] = len(filenames) if '.hg' in dirnames: dirnames.remove('.hg') lineschanged = zerodict() children = zerodict() p1distance = zerodict() p2distance = zerodict() linesinfilesadded = zerodict() fileschanged = zerodict() filesadded = zerodict() filesremoved = zerodict() linelengths = zerodict() interarrival = zerodict() parents = zerodict() dirsadded = zerodict() tzoffset = zerodict() # If a mercurial repo is available, also model the commit history. if repo: revs = scmutil.revrange(repo, revs) revs.sort() progress = ui.makeprogress(_('analyzing'), unit=_('changesets'), total=len(revs)) for i, rev in enumerate(revs): progress.update(i) ctx = repo[rev] pl = ctx.parents() pctx = pl[0] prev = pctx.rev() children[prev] += 1 p1distance[rev - prev] += 1 parents[len(pl)] += 1 tzoffset[ctx.date()[1]] += 1 if len(pl) > 1: p2distance[rev - pl[1].rev()] += 1 if prev == rev - 1: lastctx = pctx else: lastctx = repo[rev - 1] if lastctx.rev() != nullrev: timedelta = ctx.date()[0] - lastctx.date()[0] interarrival[roundto(timedelta, 300)] += 1 diffopts = diffutil.diffallopts(ui, {'git': True}) diff = sum((d.splitlines() for d in ctx.diff(pctx, opts=diffopts)), []) fileadds, diradds, fileremoves, filechanges = 0, 0, 0, 0 for filename, mar, lineadd, lineremove, isbin in parsegitdiff(diff): if isbin: continue added = sum(lineadd.itervalues(), 0) if mar == 'm': if added and lineremove: lineschanged[roundto(added, 5), roundto(lineremove, 5)] += 1 filechanges += 1 elif mar == 'a': fileadds += 1 if '/' in filename: filedir = filename.rsplit('/', 1)[0] if filedir not in pctx.dirs(): diradds += 1 linesinfilesadded[roundto(added, 5)] += 1 elif mar == 'r': fileremoves += 1 for length, count in lineadd.iteritems(): linelengths[length] += count fileschanged[filechanges] += 1 filesadded[fileadds] += 1 dirsadded[diradds] += 1 filesremoved[fileremoves] += 1 progress.complete() invchildren = zerodict() for rev, count in children.iteritems(): invchildren[count] += 1 if output != '-': ui.status(_('writing output to %s\n') % output) def pronk(d): return sorted(d.iteritems(), key=lambda x: x[1], reverse=True) json.dump({'revs': len(revs), 'initdirs': pronk(dirs), 'lineschanged': pronk(lineschanged), 'children': pronk(invchildren), 'fileschanged': pronk(fileschanged), 'filesadded': pronk(filesadded), 'linesinfilesadded': pronk(linesinfilesadded), 'dirsadded': pronk(dirsadded), 'filesremoved': pronk(filesremoved), 'linelengths': pronk(linelengths), 'parents': pronk(parents), 'p1distance': pronk(p1distance), 'p2distance': pronk(p2distance), 'interarrival': pronk(interarrival), 'tzoffset': pronk(tzoffset), }, fp) fp.close() @command('synthesize', [('c', 'count', 0, _('create given number of commits'), _('COUNT')), ('', 'dict', '', _('path to a dictionary of words'), _('FILE')), ('', 'initfiles', 0, _('initial file count to create'), _('COUNT'))], _('hg synthesize [OPTION].. DESCFILE')) def synthesize(ui, repo, descpath, **opts): '''synthesize commits based on a model of an existing repository The model must have been generated by :hg:`analyze`. Commits will be generated randomly according to the probabilities described in the model. If --initfiles is set, the repository will be seeded with the given number files following the modeled repository's directory structure. When synthesizing new content, commit descriptions, and user names, words will be chosen randomly from a dictionary that is presumed to contain one word per line. Use --dict to specify the path to an alternate dictionary to use. ''' try: fp = hg.openpath(ui, descpath) except Exception as err: raise error.Abort('%s: %s' % (descpath, err[0].strerror)) desc = json.load(fp) fp.close() def cdf(l): if not l: return [], [] vals, probs = zip(*sorted(l, key=lambda x: x[1], reverse=True)) t = float(sum(probs, 0)) s, cdfs = 0, [] for v in probs: s += v cdfs.append(s / t) return vals, cdfs lineschanged = cdf(desc['lineschanged']) fileschanged = cdf(desc['fileschanged']) filesadded = cdf(desc['filesadded']) dirsadded = cdf(desc['dirsadded']) filesremoved = cdf(desc['filesremoved']) linelengths = cdf(desc['linelengths']) parents = cdf(desc['parents']) p1distance = cdf(desc['p1distance']) p2distance = cdf(desc['p2distance']) interarrival = cdf(desc['interarrival']) linesinfilesadded = cdf(desc['linesinfilesadded']) tzoffset = cdf(desc['tzoffset']) dictfile = opts.get('dict') or '/usr/share/dict/words' try: fp = open(dictfile, 'rU') except IOError as err: raise error.Abort('%s: %s' % (dictfile, err.strerror)) words = fp.read().splitlines() fp.close() initdirs = {} if desc['initdirs']: for k, v in desc['initdirs']: initdirs[k.encode('utf-8').replace('.hg', '_hg')] = v initdirs = renamedirs(initdirs, words) initdirscdf = cdf(initdirs) def pick(cdf): return cdf[0][bisect.bisect_left(cdf[1], random.random())] def pickpath(): return os.path.join(pick(initdirscdf), random.choice(words)) def makeline(minimum=0): total = max(minimum, pick(linelengths)) c, l = 0, [] while c < total: w = random.choice(words) c += len(w) + 1 l.append(w) return ' '.join(l) wlock = repo.wlock() lock = repo.lock() nevertouch = {'.hgsub', '.hgignore', '.hgtags'} _synthesizing = _('synthesizing') _files = _('initial files') _changesets = _('changesets') # Synthesize a single initial revision adding files to the repo according # to the modeled directory structure. initcount = int(opts['initfiles']) if initcount and initdirs: pctx = repo['.'] dirs = set(pctx.dirs()) files = {} def validpath(path): # Don't pick filenames which are already directory names. if path in dirs: return False # Don't pick directories which were used as file names. while path: if path in files: return False path = os.path.dirname(path) return True progress = ui.makeprogress(_synthesizing, unit=_files, total=initcount) for i in xrange(0, initcount): progress.update(i) path = pickpath() while not validpath(path): path = pickpath() data = '%s contents\n' % path files[path] = data dir = os.path.dirname(path) while dir and dir not in dirs: dirs.add(dir) dir = os.path.dirname(dir) def filectxfn(repo, memctx, path): return context.memfilectx(repo, memctx, path, files[path]) progress.complete() message = 'synthesized wide repo with %d files' % (len(files),) mc = context.memctx(repo, [pctx.node(), nullid], message, files, filectxfn, ui.username(), '%d %d' % dateutil.makedate()) initnode = mc.commit() if ui.debugflag: hexfn = hex else: hexfn = short ui.status(_('added commit %s with %d files\n') % (hexfn(initnode), len(files))) # Synthesize incremental revisions to the repository, adding repo depth. count = int(opts['count']) heads = set(map(repo.changelog.rev, repo.heads())) progress = ui.makeprogress(_synthesizing, unit=_changesets, total=count) for i in xrange(count): progress.update(i) node = repo.changelog.node revs = len(repo) def pickhead(heads, distance): if heads: lheads = sorted(heads) rev = revs - min(pick(distance), revs) if rev < lheads[-1]: rev = lheads[bisect.bisect_left(lheads, rev)] else: rev = lheads[-1] return rev, node(rev) return nullrev, nullid r1 = revs - min(pick(p1distance), revs) p1 = node(r1) # the number of heads will grow without bound if we use a pure # model, so artificially constrain their proliferation toomanyheads = len(heads) > random.randint(1, 20) if p2distance[0] and (pick(parents) == 2 or toomanyheads): r2, p2 = pickhead(heads.difference([r1]), p2distance) else: r2, p2 = nullrev, nullid pl = [p1, p2] pctx = repo[r1] mf = pctx.manifest() mfk = mf.keys() changes = {} if mfk: for __ in xrange(pick(fileschanged)): for __ in xrange(10): fctx = pctx.filectx(random.choice(mfk)) path = fctx.path() if not (path in nevertouch or fctx.isbinary() or 'l' in fctx.flags()): break lines = fctx.data().splitlines() add, remove = pick(lineschanged) for __ in xrange(remove): if not lines: break del lines[random.randrange(0, len(lines))] for __ in xrange(add): lines.insert(random.randint(0, len(lines)), makeline()) path = fctx.path() changes[path] = '\n'.join(lines) + '\n' for __ in xrange(pick(filesremoved)): for __ in xrange(10): path = random.choice(mfk) if path not in changes: break if filesadded: dirs = list(pctx.dirs()) dirs.insert(0, '') for __ in xrange(pick(filesadded)): pathstr = '' while pathstr in dirs: path = [random.choice(dirs)] if pick(dirsadded): path.append(random.choice(words)) path.append(random.choice(words)) pathstr = '/'.join(filter(None, path)) data = '\n'.join(makeline() for __ in xrange(pick(linesinfilesadded))) + '\n' changes[pathstr] = data def filectxfn(repo, memctx, path): if path not in changes: return None return context.memfilectx(repo, memctx, path, changes[path]) if not changes: continue if revs: date = repo['tip'].date()[0] + pick(interarrival) else: date = time.time() - (86400 * count) # dates in mercurial must be positive, fit in 32-bit signed integers. date = min(0x7fffffff, max(0, date)) user = random.choice(words) + '@' + random.choice(words) mc = context.memctx(repo, pl, makeline(minimum=2), sorted(changes), filectxfn, user, '%d %d' % (date, pick(tzoffset))) newnode = mc.commit() heads.add(repo.changelog.rev(newnode)) heads.discard(r1) heads.discard(r2) progress.complete() lock.release() wlock.release() def renamedirs(dirs, words): '''Randomly rename the directory names in the per-dir file count dict.''' wordgen = itertools.cycle(words) replacements = {'': ''} def rename(dirpath): '''Recursively rename the directory and all path prefixes. The mapping from path to renamed path is stored for all path prefixes as in dynamic programming, ensuring linear runtime and consistent renaming regardless of iteration order through the model. ''' if dirpath in replacements: return replacements[dirpath] head, _ = os.path.split(dirpath) if head: head = rename(head) else: head = '' renamed = os.path.join(head, next(wordgen)) replacements[dirpath] = renamed return renamed result = [] for dirpath, count in dirs.iteritems(): result.append([rename(dirpath.lstrip(os.sep)), count]) return result