Mercurial > hg
view tests/test-pathencode.py @ 47072:4c041c71ec01
revlog: introduce an explicit tracking of what the revlog is about
Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.
In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.
So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.
The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.
Differential Revision: https://phab.mercurial-scm.org/D10352
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 06 Apr 2021 05:20:24 +0200 |
parents | 89a2afe31e82 |
children | 6000f5b25c9b |
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# 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()