view tests/test-pathencode.py @ 34857:84c6b9384d6a

log: add -L/--line-range option to follow file history by line range

We add an experimental -L/--line-range option to 'hg log' taking file patterns
along with a line range using the (new) FILE,FROMLINE-TOLINE syntax where FILE
may be a pattern (matching exactly one file). The resulting history is similar
to what the "followlines" revset except that, if --patch is specified,
only diff hunks within specified line range are shown.

Basically, this brings the CLI on par with what currently only exists in hgweb
through line selection in "file" and "annotate" views resulting in a file log
with filtered patch to only display followed line range.

The option may be specified multiple times and can be combined with --rev and
regular file patterns to further restrict revisions. Usage of this option
requires --follow; revisions are shown in descending order and renames are
followed. Only the --graph option is currently not supported.

The UI is the result of a consensus from review feedback at:

  https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-October/106749.html


The implementation spreads between commands.log() and cmdutil module.
In commands.log(), the main loop may now use a "hunksfilter" factory (similar
to "filematcher") that, for a given "rev", produces a filtering function
for diff hunks for a given file context object.
The logic to build revisions from -L/--line-range options lives in
cmdutil.getloglinerangerevs() which produces "revs", "filematcher" and
"hunksfilter" information. Revisions obtained by following files' line range
are filtered if they do not match the revset specified by --rev option. If
regular FILE arguments are passed along with -L options, both filematchers are
combined into a new matcher.

.. feature::

   Add an experimental -L/--line-range FILE,FROMLINE-TOLINE option to 'hg log'
   command to follow the history of files by line range. In combination with
   -p/--patch option, only diff hunks within specified line range will be
   displayed. Feedback, especially on UX aspects, is welcome.

# 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,
)

try:
    xrange
except NameError:
    xrange = range

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 = int(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 = int(binascii.hexlify(os.urandom(16)), 16)
        except AttributeError:
            seed = int(time.time() * 1000)

    rng = random.Random(seed)
    if runtests(rng, seed, count):
        sys.exit(1)

if __name__ == '__main__':
    main()