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view tests/test-requires.t @ 44363:f7459da77f23
nodemap: introduce an option to use mmap to read the nodemap mapping
The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.
This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).
Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:
Before:
* do not use the persistent nodemap
* use the CPython implementation of the index for nodemap
* use mmapping of the changelog index
After:
* use the MixedIndex Rust code, with the NodeTree object for nodemap access
(still in review)
* use the persistent nodemap data from disk
* access the persistent nodemap data through mmap
* use mmapping of the changelog index
The persistent nodemap greatly speed up most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.
Here are some numbers (in seconds) for the reference copy of mozilla-try:
Revset Before After abs-change speedup
-10000: 0.004622 0.005532 0.000910 × 0.83
-10: 0.000050 0.000132 0.000082 × 0.37
tip 0.000052 0.000085 0.000033 × 0.61
0 + (-10000:) 0.028222 0.005337 -0.022885 × 5.29
0 0.023521 0.000084 -0.023437 × 280.01
(-10000:) + 0 0.235539 0.005308 -0.230231 × 44.37
(-10:) + :9 0.232883 0.000180 -0.232703 ×1293.79
(-10000:) + (:99) 0.238735 0.005358 -0.233377 × 44.55
:99 + (-10000:) 0.317942 0.005593 -0.312349 × 56.84
:9 + (-10:) 0.313372 0.000179 -0.313193 ×1750.68
:9 0.316450 0.000143 -0.316307 ×2212.93
On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.
Here are some numbers (in seconds) for the reference copy of mercurial:
Revset Before After abs-change speedup
-10: 0.000065 0.000097 0.000032 × 0.67
tip 0.000063 0.000078 0.000015 × 0.80
0 0.000561 0.000079 -0.000482 × 7.10
-10000: 0.004609 0.003648 -0.000961 × 1.26
0 + (-10000:) 0.005023 0.003715 -0.001307 × 1.35
(-10:) + :9 0.002187 0.000108 -0.002079 ×20.25
(-10000:) + 0 0.006252 0.003716 -0.002536 × 1.68
(-10000:) + (:99) 0.006367 0.003707 -0.002660 × 1.71
:9 + (-10:) 0.003846 0.000110 -0.003736 ×34.96
:9 0.003854 0.000099 -0.003755 ×38.92
:99 + (-10000:) 0.007644 0.003778 -0.003866 × 2.02
Differential Revision: https://phab.mercurial-scm.org/D7894
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 11 Feb 2020 11:18:52 +0100 |
parents | fed5e57c8dc7 |
children | 4a28f5e8408e |
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$ hg init t $ cd t $ echo a > a $ hg add a $ hg commit -m test $ rm .hg/requires $ hg tip abort: unknown version (2) in revlog 00changelog.i! [255] $ echo indoor-pool > .hg/requires $ hg tip abort: repository requires features unknown to this Mercurial: indoor-pool! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ echo outdoor-pool >> .hg/requires $ hg tip abort: repository requires features unknown to this Mercurial: indoor-pool outdoor-pool! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ cd .. Test checking between features supported locally and ones required in another repository of push/pull/clone on localhost: $ mkdir supported-locally $ cd supported-locally $ hg init supported $ echo a > supported/a $ hg -R supported commit -Am '#0 at supported' adding a $ echo 'featuresetup-test' >> supported/.hg/requires $ cat > $TESTTMP/supported-locally/supportlocally.py <<EOF > from __future__ import absolute_import > from mercurial import extensions, localrepo > def featuresetup(ui, supported): > for name, module in extensions.extensions(ui): > if __name__ == module.__name__: > # support specific feature locally > supported |= {b'featuresetup-test'} > return > def uisetup(ui): > localrepo.featuresetupfuncs.add(featuresetup) > EOF $ cat > supported/.hg/hgrc <<EOF > [extensions] > # enable extension locally > supportlocally = $TESTTMP/supported-locally/supportlocally.py > EOF $ hg -R supported status $ hg init push-dst $ hg -R supported push push-dst pushing to push-dst abort: required features are not supported in the destination: featuresetup-test [255] $ hg init pull-src $ hg -R pull-src pull supported pulling from supported abort: required features are not supported in the destination: featuresetup-test [255] $ hg clone supported clone-dst abort: repository requires features unknown to this Mercurial: featuresetup-test! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ hg clone --pull supported clone-dst abort: required features are not supported in the destination: featuresetup-test [255] $ cd ..