Mercurial > hg
view tests/test-parents.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 | 4441705b7111 |
children | 8d72e29ad1e0 |
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test parents command $ hg init repo $ cd repo no working directory $ hg parents $ echo a > a $ echo b > b $ hg ci -Amab -d '0 0' adding a adding b $ echo a >> a $ hg ci -Ama -d '1 0' $ echo b >> b $ hg ci -Amb -d '2 0' $ echo c > c $ hg ci -Amc -d '3 0' adding c $ hg up -C 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo d > c $ hg ci -Amc2 -d '4 0' adding c created new head $ hg up -C 3 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg parents changeset: 3:02d851b7e549 user: test date: Thu Jan 01 00:00:03 1970 +0000 summary: c $ hg parents a changeset: 1:d786049f033a user: test date: Thu Jan 01 00:00:01 1970 +0000 summary: a hg parents c, single revision $ hg parents c changeset: 3:02d851b7e549 user: test date: Thu Jan 01 00:00:03 1970 +0000 summary: c $ hg parents -r 3 c abort: 'c' not found in manifest! [255] $ hg parents -r 2 changeset: 1:d786049f033a user: test date: Thu Jan 01 00:00:01 1970 +0000 summary: a $ hg parents -r 2 a changeset: 1:d786049f033a user: test date: Thu Jan 01 00:00:01 1970 +0000 summary: a $ hg parents -r 2 ../a abort: ../a not under root '$TESTTMP/repo' [255] cd dir; hg parents -r 2 ../a $ mkdir dir $ cd dir $ hg parents -r 2 ../a changeset: 1:d786049f033a user: test date: Thu Jan 01 00:00:01 1970 +0000 summary: a $ hg parents -r 2 path:a changeset: 1:d786049f033a user: test date: Thu Jan 01 00:00:01 1970 +0000 summary: a $ cd .. $ hg parents -r 2 glob:a abort: can only specify an explicit filename [255] merge working dir with 2 parents, hg parents c $ HGMERGE=true hg merge merging c 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg parents c changeset: 3:02d851b7e549 user: test date: Thu Jan 01 00:00:03 1970 +0000 summary: c changeset: 4:48cee28d4b4e tag: tip parent: 1:d786049f033a user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: c2 merge working dir with 1 parent, hg parents $ hg up -C 2 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ HGMERGE=true hg merge -r 4 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg parents changeset: 2:6cfac479f009 user: test date: Thu Jan 01 00:00:02 1970 +0000 summary: b changeset: 4:48cee28d4b4e tag: tip parent: 1:d786049f033a user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: c2 merge working dir with 1 parent, hg parents c $ hg parents c changeset: 4:48cee28d4b4e tag: tip parent: 1:d786049f033a user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: c2 $ cd ..