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view tests/helpers-testrepo.sh @ 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> |
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date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | 152f1b47e0ad |
children |
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# In most cases, the mercurial repository can be read by the bundled hg, but # that isn't always true because third-party extensions may change the store # format, for example. In which case, the system hg installation is used. # # We want to use the hg version being tested when interacting with the test # repository, and the system hg when interacting with the mercurial source code # repository. # # The mercurial source repository was typically orignally cloned with the # system mercurial installation, and may require extensions or settings from # the system installation. if [ -n "$HGTESTEXTRAEXTENSIONS" ]; then for extension in $HGTESTEXTRAEXTENSIONS; do extraoptions="$extraoptions --config extensions.$extension=!" done fi syshg () { ( syshgenv exec hg "$@" ) } # Revert the environment so that running "hg" runs the system hg # rather than the test hg installation. syshgenv () { . "$HGTEST_RESTOREENV" HGPLAIN=1 export HGPLAIN } # The test-repo is a live hg repository which may have evolution markers # created, e.g. when a ~/.hgrc enabled evolution. # # Tests may be run using a custom HGRCPATH, which do not enable evolution # markers by default. # # If test-repo includes evolution markers, and we do not enable evolution # markers, hg will occasionally complain when it notices them, which disrupts # tests resulting in sporadic failures. # # Since we aren't performing any write operations on the test-repo, there's # no harm in telling hg that we support evolution markers, which is what the # following lines for the hgrc file do: cat >> "$HGRCPATH" << EOF [experimental] evolution = createmarkers EOF # Use the system hg command if the bundled hg can't read the repository with # no warning nor error. if [ -n "`hg id -R "$TESTDIR/.." 2>&1 >/dev/null`" ]; then alias testrepohg=syshg alias testrepohgenv=syshgenv else alias testrepohg="hg $extraoptions" alias testrepohgenv=: fi