dagop: factor out generator of ancestor nodes
# ancestors(tip) using hg repo
1) 0.068976
2) 0.068527
# This is a randomized test that generates different pathnames every
# time it is invoked, and tests the encoding of those pathnames.
#
# It uses a simple probabilistic model to generate valid pathnames
# that have proven likely to expose bugs and divergent behavior in
# different encoding implementations.
from __future__ import absolute_import, print_function
import binascii
import collections
import itertools
import math
import os
import random
import sys
import time
from mercurial import (
store,
)
validchars = set(map(chr, range(0, 256)))
alphanum = range(ord('A'), ord('Z'))
for c in '\0/':
validchars.remove(c)
winreserved = ('aux con prn nul'.split() +
['com%d' % i for i in xrange(1, 10)] +
['lpt%d' % i for i in xrange(1, 10)])
def casecombinations(names):
'''Build all case-diddled combinations of names.'''
combos = set()
for r in names:
for i in xrange(len(r) + 1):
for c in itertools.combinations(xrange(len(r)), i):
d = r
for j in c:
d = ''.join((d[:j], d[j].upper(), d[j + 1:]))
combos.add(d)
return sorted(combos)
def buildprobtable(fp, cmd='hg manifest tip'):
'''Construct and print a table of probabilities for path name
components. The numbers are percentages.'''
counts = collections.defaultdict(lambda: 0)
for line in os.popen(cmd).read().splitlines():
if line[-2:] in ('.i', '.d'):
line = line[:-2]
if line.startswith('data/'):
line = line[5:]
for c in line:
counts[c] += 1
for c in '\r/\n':
counts.pop(c, None)
t = sum(counts.itervalues()) / 100.0
fp.write('probtable = (')
for i, (k, v) in enumerate(sorted(counts.iteritems(), key=lambda x: x[1],
reverse=True)):
if (i % 5) == 0:
fp.write('\n ')
vt = v / t
if vt < 0.0005:
break
fp.write('(%r, %.03f), ' % (k, vt))
fp.write('\n )\n')
# A table of character frequencies (as percentages), gleaned by
# looking at filelog names from a real-world, very large repo.
probtable = (
('t', 9.828), ('e', 9.042), ('s', 8.011), ('a', 6.801), ('i', 6.618),
('g', 5.053), ('r', 5.030), ('o', 4.887), ('p', 4.363), ('n', 4.258),
('l', 3.830), ('h', 3.693), ('_', 3.659), ('.', 3.377), ('m', 3.194),
('u', 2.364), ('d', 2.296), ('c', 2.163), ('b', 1.739), ('f', 1.625),
('6', 0.666), ('j', 0.610), ('y', 0.554), ('x', 0.487), ('w', 0.477),
('k', 0.476), ('v', 0.473), ('3', 0.336), ('1', 0.335), ('2', 0.326),
('4', 0.310), ('5', 0.305), ('9', 0.302), ('8', 0.300), ('7', 0.299),
('q', 0.298), ('0', 0.250), ('z', 0.223), ('-', 0.118), ('C', 0.095),
('T', 0.087), ('F', 0.085), ('B', 0.077), ('S', 0.076), ('P', 0.076),
('L', 0.059), ('A', 0.058), ('N', 0.051), ('D', 0.049), ('M', 0.046),
('E', 0.039), ('I', 0.035), ('R', 0.035), ('G', 0.028), ('U', 0.026),
('W', 0.025), ('O', 0.017), ('V', 0.015), ('H', 0.013), ('Q', 0.011),
('J', 0.007), ('K', 0.005), ('+', 0.004), ('X', 0.003), ('Y', 0.001),
)
for c, _ in probtable:
validchars.remove(c)
validchars = list(validchars)
def pickfrom(rng, table):
c = 0
r = rng.random() * sum(i[1] for i in table)
for i, p in table:
c += p
if c >= r:
return i
reservedcombos = casecombinations(winreserved)
# The first component of a name following a slash.
firsttable = (
(lambda rng: pickfrom(rng, probtable), 90),
(lambda rng: rng.choice(validchars), 5),
(lambda rng: rng.choice(reservedcombos), 5),
)
# Components of a name following the first.
resttable = firsttable[:-1]
# Special suffixes.
internalsuffixcombos = casecombinations('.hg .i .d'.split())
# The last component of a path, before a slash or at the end of a name.
lasttable = resttable + (
(lambda rng: '', 95),
(lambda rng: rng.choice(internalsuffixcombos), 5),
)
def makepart(rng, k):
'''Construct a part of a pathname, without slashes.'''
p = pickfrom(rng, firsttable)(rng)
l = len(p)
ps = [p]
maxl = rng.randint(1, k)
while l < maxl:
p = pickfrom(rng, resttable)(rng)
l += len(p)
ps.append(p)
ps.append(pickfrom(rng, lasttable)(rng))
return ''.join(ps)
def makepath(rng, j, k):
'''Construct a complete pathname.'''
return ('data/' + '/'.join(makepart(rng, k) for _ in xrange(j)) +
rng.choice(['.d', '.i']))
def genpath(rng, count):
'''Generate random pathnames with gradually increasing lengths.'''
mink, maxk = 1, 4096
def steps():
for i in xrange(count):
yield mink + int(round(math.sqrt((maxk - mink) * float(i) / count)))
for k in steps():
x = rng.randint(1, k)
y = rng.randint(1, k)
yield makepath(rng, x, y)
def runtests(rng, seed, count):
nerrs = 0
for p in genpath(rng, count):
h = store._pathencode(p) # uses C implementation, if available
r = store._hybridencode(p, True) # reference implementation in Python
if h != r:
if nerrs == 0:
print('seed:', hex(seed)[:-1], file=sys.stderr)
print("\np: '%s'" % p.encode("string_escape"), file=sys.stderr)
print("h: '%s'" % h.encode("string_escape"), file=sys.stderr)
print("r: '%s'" % r.encode("string_escape"), file=sys.stderr)
nerrs += 1
return nerrs
def main():
import getopt
# Empirically observed to take about a second to run
count = 100
seed = None
opts, args = getopt.getopt(sys.argv[1:], 'c:s:',
['build', 'count=', 'seed='])
for o, a in opts:
if o in ('-c', '--count'):
count = int(a)
elif o in ('-s', '--seed'):
seed = long(a, base=0) # accepts base 10 or 16 strings
elif o == '--build':
buildprobtable(sys.stdout,
'find .hg/store/data -type f && '
'cat .hg/store/fncache 2>/dev/null')
sys.exit(0)
if seed is None:
try:
seed = long(binascii.hexlify(os.urandom(16)), 16)
except AttributeError:
seed = long(time.time() * 1000)
rng = random.Random(seed)
if runtests(rng, seed, count):
sys.exit(1)
if __name__ == '__main__':
main()