Mercurial > hg
view tests/test-ssh-repoerror.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 | b6673e9bdcf6 |
children | 95c4cca641f6 |
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#require unix-permissions no-root initial setup $ cat << EOF >> $HGRCPATH > [ui] > ssh="$PYTHON" "$TESTDIR/dummyssh" > EOF repository itself is non-readable --------------------------------- $ hg init no-read $ hg id ssh://user@dummy/no-read 000000000000 $ chmod a-rx no-read $ hg id ssh://user@dummy/no-read remote: abort: Permission denied: *$TESTTMP/no-read/.hg* (glob) abort: no suitable response from remote hg! [255] special case files are visible, but unreadable ---------------------------------------------- This is "similar" to the test above, but the directory is "traversable". This seems an unexpected case in real life, but we test it anyway. $ hg init other $ hg id ssh://user@dummy/other 000000000000 $ for item in `find other | sort -r` ; do > chmod a-r $item > done $ hg id ssh://user@dummy/other remote: abort: Permission denied: '$TESTTMP/other/.hg/requires' abort: no suitable response from remote hg! [255] directory toward the repository is read only -------------------------------------------- $ mkdir deep $ hg init deep/nested $ hg id ssh://user@dummy/deep/nested 000000000000 $ chmod a-rx deep $ hg id ssh://user@dummy/deep/nested remote: abort: Permission denied: *$TESTTMP/deep/nested/.hg* (glob) abort: no suitable response from remote hg! [255] repository has wrong requirement -------------------------------- $ hg init repo-future $ hg id ssh://user@dummy/repo-future 000000000000 $ echo flying-car >> repo-future/.hg/requires $ hg id ssh://user@dummy/repo-future remote: abort: repository requires features unknown to this Mercurial: flying-car! remote: (see https://mercurial-scm.org/wiki/MissingRequirement for more information) abort: no suitable response from remote hg! [255]