tests/test-pathencode.py
author Gregory Szorc <gregory.szorc@gmail.com>
Wed, 04 Feb 2015 14:11:45 -0800
changeset 24068 4e02418b4236
parent 20938 e9725e18bdf8
child 26098 ce26928cbe41
permissions -rw-r--r--
color: support a different color mode when the pager is active MSYS on Windows has a terminal that supports the "win32" color mode (which "auto" properly detects for us). However, a popularily configured pager in that environment (GNU less) only supports the "ansi" color mode. This patch teaches color about a new config option: pagermode. It behaves like "mode" but is only consulted when the pager is active for the current command. MSYS users can now set "pagermode = ansi" and get a colorful experience that just works. Previously, MSYS users would have to live without color when using GNU less as the pager, would have to manually configure the pager to attend every command, or would have gibberish if "ansi" was used without the pager.

# 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()