revset: introduce an abstractsmartset class
This class documents all methods required by a smartset. This makes it easier
for people to respect the API and ensure we fail loudly when something does
not. It will later also contain common default implementations for multiple
methods, making it easier to have smartset classes with minimal work.
# 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
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
'''
import bisect, collections, json, os, random, time, sys
from mercurial import cmdutil, context, patch, scmutil, util, hg
from mercurial.i18n import _
from mercurial.node import nullrev, nullid
testedwith = 'internal'
cmdtable = {}
command = cmdutil.command(cmdtable)
newfile = set(('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'))
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.
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.
'''
revs = list(revs)
revs.extend(opts['rev'])
if not revs:
revs = [':']
output = opts['output']
if not output:
output = os.path.basename(repo.root) + '.json'
if output == '-':
fp = sys.stdout
else:
fp = open(output, 'w')
revs = scmutil.revrange(repo, revs)
revs.sort()
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()
progress = ui.progress
_analyzing = _('analyzing')
_changesets = _('changesets')
_total = len(revs)
for i, rev in enumerate(revs):
progress(_analyzing, i, unit=_changesets, total=_total)
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:
interarrival[roundto(ctx.date()[0] - lastctx.date()[0], 300)] += 1
diff = sum((d.splitlines() for d in ctx.diff(pctx, git=True)), [])
fileadds, diradds, fileremoves, filechanges = 0, 0, 0, 0
for filename, mar, lineadd, lineremove, binary in parsegitdiff(diff):
if binary:
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
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),
'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'))],
_('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.
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, err:
raise util.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, err:
raise util.Abort('%s: %s' % (dictfile, err.strerror))
words = fp.read().splitlines()
fp.close()
def pick(cdf):
return cdf[0][bisect.bisect_left(cdf[1], random.random())]
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 = set(('.hgsub', '.hgignore', '.hgtags'))
progress = ui.progress
_synthesizing = _('synthesizing')
_changesets = _('changesets')
count = int(opts['count'])
heads = set(map(repo.changelog.rev, repo.heads()))
for i in xrange(count):
progress(_synthesizing, i, unit=_changesets, total=count)
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] = context.memfilectx(repo, path,
'\n'.join(lines) + '\n')
for __ in xrange(pick(filesremoved)):
path = random.choice(mfk)
for __ in xrange(10):
path = random.choice(mfk)
if path not in changes:
changes[path] = None
break
if filesadded:
dirs = list(pctx.dirs())
dirs.append('')
for __ in xrange(pick(filesadded)):
path = [random.choice(dirs)]
if pick(dirsadded):
path.append(random.choice(words))
path.append(random.choice(words))
path = '/'.join(filter(None, path))
data = '\n'.join(makeline()
for __ in xrange(pick(linesinfilesadded))) + '\n'
changes[path] = context.memfilectx(repo, path, data)
def filectxfn(repo, memctx, path):
return changes[path]
if not changes:
continue
if revs:
date = repo['tip'].date()[0] + pick(interarrival)
else:
date = time.time() - (86400 * count)
user = random.choice(words) + '@' + random.choice(words)
mc = context.memctx(repo, pl, makeline(minimum=2),
sorted(changes.iterkeys()),
filectxfn, user, '%d %d' % (date, pick(tzoffset)))
newnode = mc.commit()
heads.add(repo.changelog.rev(newnode))
heads.discard(r1)
heads.discard(r2)
lock.release()
wlock.release()