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
Test the EOL hook
$ hg init main
$ cat > main/.hg/hgrc <<EOF
> [hooks]
> pretxnchangegroup = python:hgext.eol.hook
> EOF
$ hg clone main fork
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd fork
Create repo
$ cat > .hgeol <<EOF
> [patterns]
> mixed.txt = BIN
> crlf.txt = CRLF
> **.txt = native
> EOF
$ hg add .hgeol
$ hg commit -m 'Commit .hgeol'
$ printf "first\nsecond\nthird\n" > a.txt
$ hg add a.txt
$ hg commit -m 'LF a.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
$ printf "first\r\nsecond\r\nthird\n" > a.txt
$ hg commit -m 'CRLF a.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup hook failed: end-of-line check failed:
a.txt in a8ee6548cd86 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
a.txt in a8ee6548cd86 should not have CRLF line endings
[255]
$ printf "first\nsecond\nthird\n" > a.txt
$ hg commit -m 'LF a.txt (fixed)'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
$ printf "first\nsecond\nthird\n" > crlf.txt
$ hg add crlf.txt
$ hg commit -m 'LF crlf.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup hook failed: end-of-line check failed:
crlf.txt in 004ba2132725 should not have LF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
crlf.txt in 004ba2132725 should not have LF line endings
[255]
$ printf "first\r\nsecond\r\nthird\r\n" > crlf.txt
$ hg commit -m 'CRLF crlf.txt (fixed)'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
$ printf "first\r\nsecond" > b.txt
$ hg add b.txt
$ hg commit -m 'CRLF b.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
$ hg up -r -2
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ printf "some\nother\nfile" > c.txt
$ hg add c.txt
$ hg commit -m "LF c.txt, b.txt doesn't exist here"
created new head
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
Test checkheadshook alias
$ cat > ../main/.hg/hgrc <<EOF
> [hooks]
> pretxnchangegroup = python:hgext.eol.checkheadshook
> EOF
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
We can fix the head and push again
$ hg up 6
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ printf "first\nsecond" > b.txt
$ hg ci -m "remove CRLF from b.txt"
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 2 files (+1 heads)
$ hg -R ../main rollback
repository tip rolled back to revision 5 (undo push)
Test it still fails with checkallhook
$ cat > ../main/.hg/hgrc <<EOF
> [hooks]
> pretxnchangegroup = python:hgext.eol.checkallhook
> EOF
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
But we can push the clean head
$ hg push -r7 -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
Test multiple files/revisions output
$ printf "another\r\nbad\r\none" > d.txt
$ hg add d.txt
$ hg ci -m "add d.txt"
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
d.txt in a7040e68714f should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
d.txt in a7040e68714f should not have CRLF line endings
[255]
$ cd ..