Mercurial > hg
view tests/test-pathencode.py @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | 1b230e19d044 |
children | 2372284d9457 |
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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(counts.itervalues()) / 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()