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view tests/test-util.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 | 331ab85e910b |
children | 2372284d9457 |
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# unit tests for mercuril.util utilities from __future__ import absolute_import import contextlib import itertools import unittest from mercurial import pycompat, util, utils @contextlib.contextmanager def mocktimer(incr=0.1, *additional_targets): """Replaces util.timer and additional_targets with a mock The timer starts at 0. On each call the time incremented by the value of incr. If incr is an iterable, then the time is incremented by the next value from that iterable, looping in a cycle when reaching the end. additional_targets must be a sequence of (object, attribute_name) tuples; the mock is set with setattr(object, attribute_name, mock). """ time = [0] try: incr = itertools.cycle(incr) except TypeError: incr = itertools.repeat(incr) def timer(): time[0] += next(incr) return time[0] # record original values orig = util.timer additional_origs = [(o, a, getattr(o, a)) for o, a in additional_targets] # mock out targets util.timer = timer for obj, attr in additional_targets: setattr(obj, attr, timer) try: yield finally: # restore originals util.timer = orig for args in additional_origs: setattr(*args) # attr.s default factory for util.timedstats.start binds the timer we # need to mock out. _start_default = (util.timedcmstats.start.default, 'factory') @contextlib.contextmanager def capturestderr(): """Replace utils.procutil.stderr with a pycompat.bytesio instance The instance is made available as the return value of __enter__. This contextmanager is reentrant. """ orig = utils.procutil.stderr utils.procutil.stderr = pycompat.bytesio() try: yield utils.procutil.stderr finally: utils.procutil.stderr = orig class timedtests(unittest.TestCase): def testtimedcmstatsstr(self): stats = util.timedcmstats() self.assertEqual(str(stats), '<unknown>') self.assertEqual(bytes(stats), b'<unknown>') stats.elapsed = 12.34 self.assertEqual(str(stats), pycompat.sysstr(util.timecount(12.34))) self.assertEqual(bytes(stats), util.timecount(12.34)) def testtimedcmcleanexit(self): # timestamps 1, 4, elapsed time of 4 - 1 = 3 with mocktimer([1, 3], _start_default): with util.timedcm('pass') as stats: # actual context doesn't matter pass self.assertEqual(stats.start, 1) self.assertEqual(stats.elapsed, 3) self.assertEqual(stats.level, 1) def testtimedcmnested(self): # timestamps 1, 3, 6, 10, elapsed times of 6 - 3 = 3 and 10 - 1 = 9 with mocktimer([1, 2, 3, 4], _start_default): with util.timedcm('outer') as outer_stats: with util.timedcm('inner') as inner_stats: # actual context doesn't matter pass self.assertEqual(outer_stats.start, 1) self.assertEqual(outer_stats.elapsed, 9) self.assertEqual(outer_stats.level, 1) self.assertEqual(inner_stats.start, 3) self.assertEqual(inner_stats.elapsed, 3) self.assertEqual(inner_stats.level, 2) def testtimedcmexception(self): # timestamps 1, 4, elapsed time of 4 - 1 = 3 with mocktimer([1, 3], _start_default): try: with util.timedcm('exceptional') as stats: raise ValueError() except ValueError: pass self.assertEqual(stats.start, 1) self.assertEqual(stats.elapsed, 3) self.assertEqual(stats.level, 1) def testtimeddecorator(self): @util.timed def testfunc(callcount=1): callcount -= 1 if callcount: testfunc(callcount) # timestamps 1, 2, 3, 4, elapsed time of 3 - 2 = 1 and 4 - 1 = 3 with mocktimer(1, _start_default): with capturestderr() as out: testfunc(2) self.assertEqual(out.getvalue(), ( b' testfunc: 1.000 s\n' b' testfunc: 3.000 s\n' )) if __name__ == '__main__': import silenttestrunner silenttestrunner.main(__name__)