Mercurial > hg
view contrib/synthrepo.py @ 42377:0546ead39a7e stable
manifest: avoid corruption by dropping removed files with pure (issue5801)
Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`. But no effort was made to
ignore them when compacting the dictionary into text form. This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible. As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry. This typically resulted in
a ValueError complaining about unsorted manifest entries.
Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot. A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.
In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes. However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.
[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511
author | Matt Harbison <matt_harbison@yahoo.com> |
---|---|
date | Thu, 23 May 2019 21:54:24 -0400 |
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