help: add a mechanism to change flags' help depending on config
It seems reasonable to have a similar mechanism for the rest of the
help, but no such thing is implemented.
The goal is to make the help of commands clearer in the presence of
significant default changes, like tweakdefaults or with company-wide
hgrcs. In these cases, a user looking at the help of a command doesn't
exactly know what his hgrc is doing.
Apply to this to the --git option of commands that display diffs, as
this option in particular causes confusion for some reason.
Differential Revision: https://phab.mercurial-scm.org/D8100
# 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 (
pycompat,
store,
)
try:
xrange
except NameError:
xrange = range
validchars = set(map(pycompat.bytechr, range(0, 256)))
alphanum = range(ord('A'), ord('Z'))
for c in (b'\0', b'/'):
validchars.remove(c)
winreserved = (
b'aux con prn nul'.split()
+ [b'com%d' % i for i in xrange(1, 10)]
+ [b'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 = b''.join((d[:j], d[j : j + 1].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(pycompat.itervalues(counts)) / 100.0
fp.write('probtable = (')
for i, (k, v) in enumerate(
sorted(counts.items(), 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 = (
(b't', 9.828),
(b'e', 9.042),
(b's', 8.011),
(b'a', 6.801),
(b'i', 6.618),
(b'g', 5.053),
(b'r', 5.030),
(b'o', 4.887),
(b'p', 4.363),
(b'n', 4.258),
(b'l', 3.830),
(b'h', 3.693),
(b'_', 3.659),
(b'.', 3.377),
(b'm', 3.194),
(b'u', 2.364),
(b'd', 2.296),
(b'c', 2.163),
(b'b', 1.739),
(b'f', 1.625),
(b'6', 0.666),
(b'j', 0.610),
(b'y', 0.554),
(b'x', 0.487),
(b'w', 0.477),
(b'k', 0.476),
(b'v', 0.473),
(b'3', 0.336),
(b'1', 0.335),
(b'2', 0.326),
(b'4', 0.310),
(b'5', 0.305),
(b'9', 0.302),
(b'8', 0.300),
(b'7', 0.299),
(b'q', 0.298),
(b'0', 0.250),
(b'z', 0.223),
(b'-', 0.118),
(b'C', 0.095),
(b'T', 0.087),
(b'F', 0.085),
(b'B', 0.077),
(b'S', 0.076),
(b'P', 0.076),
(b'L', 0.059),
(b'A', 0.058),
(b'N', 0.051),
(b'D', 0.049),
(b'M', 0.046),
(b'E', 0.039),
(b'I', 0.035),
(b'R', 0.035),
(b'G', 0.028),
(b'U', 0.026),
(b'W', 0.025),
(b'O', 0.017),
(b'V', 0.015),
(b'H', 0.013),
(b'Q', 0.011),
(b'J', 0.007),
(b'K', 0.005),
(b'+', 0.004),
(b'X', 0.003),
(b'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(b'.hg .i .d'.split())
# The last component of a path, before a slash or at the end of a name.
lasttable = resttable + (
(lambda rng: b'', 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 b''.join(ps)
def makepath(rng, j, k):
'''Construct a complete pathname.'''
return (
b'data/'
+ b'/'.join(makepart(rng, k) for _ in xrange(j))
+ rng.choice([b'.d', b'.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()