Mercurial > hg
view contrib/bdiff-torture.py @ 41247:a89b20a49c13
rust-cpython: using MissingAncestors from Python code
As precedently done with LazyAncestors on cpython.rs, we test for the
presence of the 'rustext' module.
incrementalmissingrevs() has two callers within the Mercurial core:
`setdiscovery.partialdiscovery` and the `only()` revset.
This move shows a significant discovery performance improvement
in cases where the baseline is slow: using perfdiscovery on the PyPy
repos, prepared with `contrib/discovery-helper <repo> 50 100`, we
get averaged medians of 403ms with the Rust version vs 742ms without
(about 45% better).
But there are still indications that performance can be worse in cases
the baseline is fast, possibly due to the conversion from Python to
Rust and back becoming the bottleneck. We could measure this on
mozilla-central in cases were the delta is just a few changesets.
This requires confirmation, but if that's the reason, then an
upcoming `partialdiscovery` fully in Rust should solve the problem.
Differential Revision: https://phab.mercurial-scm.org/D5551
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Fri, 30 Nov 2018 14:35:57 +0100 |
parents | 0c73634d0570 |
children | 876494fd967d |
line wrap: on
line source
# Randomized torture test generation for bdiff from __future__ import absolute_import, print_function import random import sys from mercurial import ( mdiff, ) def reducetest(a, b): tries = 0 reductions = 0 print("reducing...") while tries < 1000: a2 = "\n".join(l for l in a.splitlines() if random.randint(0, 100) > 0) + "\n" b2 = "\n".join(l for l in b.splitlines() if random.randint(0, 100) > 0) + "\n" if a2 == a and b2 == b: continue if a2 == b2: continue tries += 1 try: test1(a, b) except Exception as inst: reductions += 1 tries = 0 a = a2 b = b2 print("reduced:", reductions, len(a) + len(b), repr(a), repr(b)) try: test1(a, b) except Exception as inst: print("failed:", inst) sys.exit(0) def test1(a, b): d = mdiff.textdiff(a, b) if not d: raise ValueError("empty") c = mdiff.patches(a, [d]) if c != b: raise ValueError("bad") def testwrap(a, b): try: test1(a, b) return except Exception as inst: pass print("exception:", inst) reducetest(a, b) def test(a, b): testwrap(a, b) testwrap(b, a) def rndtest(size, noise): a = [] src = " aaaaaaaabbbbccd" for x in xrange(size): a.append(src[random.randint(0, len(src) - 1)]) while True: b = [c for c in a if random.randint(0, 99) > noise] b2 = [] for c in b: b2.append(c) while random.randint(0, 99) < noise: b2.append(src[random.randint(0, len(src) - 1)]) if b2 != a: break a = "\n".join(a) + "\n" b = "\n".join(b2) + "\n" test(a, b) maxvol = 10000 startsize = 2 while True: size = startsize count = 0 while size < maxvol: print(size) volume = 0 while volume < maxvol: rndtest(size, 2) volume += size count += 2 size *= 2 maxvol *= 4 startsize *= 4