Mercurial > hg
view tests/test-bundle-vs-outgoing.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 | eb586ed5d8ce |
children |
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this structure seems to tickle a bug in bundle's search for changesets, so first we have to recreate it o 8 | | o 7 | | | o 6 |/| o | 5 | | o | 4 | | | o 3 | | | o 2 |/ o 1 | o 0 $ mkrev() > { > revno=$1 > echo "rev $revno" > echo "rev $revno" > foo.txt > hg -q ci -m"rev $revno" > } setup test repo1 $ hg init repo1 $ cd repo1 $ echo "rev 0" > foo.txt $ hg ci -Am"rev 0" adding foo.txt $ mkrev 1 rev 1 first branch $ mkrev 2 rev 2 $ mkrev 3 rev 3 back to rev 1 to create second branch $ hg up -r1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ mkrev 4 rev 4 $ mkrev 5 rev 5 merge first branch to second branch $ hg up -C -r5 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ HGMERGE=internal:local hg merge 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ echo "merge rev 5, rev 3" > foo.txt $ hg ci -m"merge first branch to second branch" one more commit following the merge $ mkrev 7 rev 7 back to "second branch" to make another head $ hg up -r5 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ mkrev 8 rev 8 the story so far $ hg log -G --template "{rev}\n" @ 8 | | o 7 | | | o 6 |/| o | 5 | | o | 4 | | | o 3 | | | o 2 |/ o 1 | o 0 check that "hg outgoing" really does the right thing sanity check of outgoing: expect revs 4 5 6 7 8 $ hg clone -r3 . ../repo2 adding changesets adding manifests adding file changes added 4 changesets with 4 changes to 1 files new changesets 6ae4cca4e39a:478f191e53f8 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved this should (and does) report 5 outgoing revisions: 4 5 6 7 8 $ hg outgoing --template "{rev}\n" ../repo2 comparing with ../repo2 searching for changes 4 5 6 7 8 test bundle (destination repo): expect 5 revisions this should bundle the same 5 revisions that outgoing reported, but it actually bundles 7 $ hg bundle foo.bundle ../repo2 searching for changes 5 changesets found test bundle (base revision): expect 5 revisions this should (and does) give exactly the same result as bundle with a destination repo... i.e. it's wrong too $ hg bundle --base 3 foo.bundle 5 changesets found $ cd ..