view tests/test-pathencode.py @ 23603:d74eb8d477d5

memctx: calculate manifest more efficiently

Before this patch, "memctx._manifest" updates all entries in the
(parent) manifest. But this is inefficiency, because almost all files
may be clean in that context.

On the other hand, just updating entries for changed "files" specified
at construction causes unexpected abortion, when there is at least one
newly removed file (see issue4470 for detail).

To calculate manifest more efficiently, this patch replaces
"pman.iteritems()" for the loop by "self._status.modified" to avoid
updating entries for clean or removed files

Examination of removal is also omitted, because removed files aren't
treated in this loop (= "self[f]" returns not None always).

# 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 behaviour in
# different encoding implementations.

from mercurial import store
import binascii, itertools, math, os, random, sys, time
import collections

if sys.version_info[:2] < (2, 6):
    sys.exit(0)

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 >> sys.stderr, 'seed:', hex(seed)[:-1]
            print >> sys.stderr, "\np: '%s'" % p.encode("string_escape")
            print >> sys.stderr, "h: '%s'" % h.encode("string_escape")
            print >> sys.stderr, "r: '%s'" % r.encode("string_escape")
            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()