manifest: persist the manifestfulltext cache
Reconstructing the manifest from the revlog takes time, so much so that there
already is a LRU cache to avoid having to load a manifest multiple times.
This patch persists that LRU cache in the .hg/cache directory, so we can re-use
this cache across hg commands. Commit benchmark (run on Macos 10.13 on a
2017-model Macbook Pro with Core i7 2.9GHz and flash drive), testing without
and with patch run 5 times, baseline is r2a227782e754:
* committing to an existing file, against the mozilla-central repository.
Baseline real time average 1.9692, with patch 1.3786.
A new debugcommand "hg debugmanifestfulltextcache" lets you inspect the cache,
clear it, or add specific manifest nodeids to it. When calling
repo.updatecaches(), the manifest(s) for the working copy parents are added to
the cache.
The hg perfmanifest command has an additional --clear-disk switch to clear this
cache when testing manifest loading performance.
Using this command to test performance on the firefox repository for revision
f947d902ed91, whose manifest has a delta chain length of 60540, we see:
$ hg perfmanifest f947d902ed91 --clear-disk
! wall 0.972253 comb 0.970000 user 0.850000 sys 0.120000 (best of 10)
$ hg debugmanifestfulltextcache -a `hg log --debug -r f947d902ed91 | grep manifest | cut -d: -f3`
Cache contains 1 manifest entries, in order of most to least recent:
id: 0294517df4aad07c70701db43bc7ff24c3ce7dbc, size 25.6 MB
Total cache data size 25.6 MB, on-disk 0 bytes
$ hg perfmanifest f947d902ed91
! wall 0.036748 comb 0.040000 user 0.020000 sys 0.020000 (best of 100)
Worst-case scenario: a manifest text loaded from a single delta; in the firefox
repository manifest node 9a1246ff762e is the chain base for the manifest
attached to revision f947d902ed91. Loading this from a full cache file is just
as fast as without the cache; the extra node ids ensure a big full cache:
$ for node in 9a1246ff762e 1a1922c14a3e 54a31d11a36a 0294517df4aa; do
> hgd debugmanifestfulltextcache -a $node > /dev/null
> done
$ hgd perfmanifest -m 9a1246ff762e
! wall 0.077513 comb 0.080000 user 0.030000 sys 0.050000 (best of 100)
$ hgd perfmanifest -m 9a1246ff762e --clear-disk
! wall 0.078547 comb 0.080000 user 0.070000 sys 0.010000 (best of 100)
#require hardlink reporevlogstore
$ cat > nlinks.py <<EOF
> from __future__ import print_function
> import sys
> from mercurial import util
> for f in sorted(sys.stdin.readlines()):
> f = f[:-1]
> print(util.nlinks(f), f)
> EOF
$ nlinksdir()
> {
> find "$@" -type f | $PYTHON $TESTTMP/nlinks.py
> }
Some implementations of cp can't create hardlinks (replaces 'cp -al' on Linux):
$ cat > linkcp.py <<EOF
> from __future__ import absolute_import
> import sys
> from mercurial import util
> util.copyfiles(sys.argv[1], sys.argv[2], hardlink=True)
> EOF
$ linkcp()
> {
> $PYTHON $TESTTMP/linkcp.py $1 $2
> }
Prepare repo r1:
$ hg init r1
$ cd r1
$ echo c1 > f1
$ hg add f1
$ hg ci -m0
$ mkdir d1
$ cd d1
$ echo c2 > f2
$ hg add f2
$ hg ci -m1
$ cd ../..
$ nlinksdir r1/.hg/store
1 r1/.hg/store/00changelog.i
1 r1/.hg/store/00manifest.i
1 r1/.hg/store/data/d1/f2.i
1 r1/.hg/store/data/f1.i
1 r1/.hg/store/fncache (repofncache !)
1 r1/.hg/store/phaseroots
1 r1/.hg/store/undo
1 r1/.hg/store/undo.backup.fncache (repofncache !)
1 r1/.hg/store/undo.backupfiles
1 r1/.hg/store/undo.phaseroots
Create hardlinked clone r2:
$ hg clone -U --debug r1 r2 --config progress.debug=true
linking: 1
linking: 2
linking: 3
linking: 4
linking: 5
linking: 6
linking: 7
linked 7 files
Create non-hardlinked clone r3:
$ hg clone --pull r1 r3
requesting all changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
new changesets 40d85e9847f2:7069c422939c
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
Repos r1 and r2 should now contain hardlinked files:
$ nlinksdir r1/.hg/store
2 r1/.hg/store/00changelog.i
2 r1/.hg/store/00manifest.i
2 r1/.hg/store/data/d1/f2.i
2 r1/.hg/store/data/f1.i
2 r1/.hg/store/fncache (repofncache !)
1 r1/.hg/store/phaseroots
1 r1/.hg/store/undo
1 r1/.hg/store/undo.backup.fncache (repofncache !)
1 r1/.hg/store/undo.backupfiles
1 r1/.hg/store/undo.phaseroots
$ nlinksdir r2/.hg/store
2 r2/.hg/store/00changelog.i
2 r2/.hg/store/00manifest.i
2 r2/.hg/store/data/d1/f2.i
2 r2/.hg/store/data/f1.i
2 r2/.hg/store/fncache (repofncache !)
Repo r3 should not be hardlinked:
$ nlinksdir r3/.hg/store
1 r3/.hg/store/00changelog.i
1 r3/.hg/store/00manifest.i
1 r3/.hg/store/data/d1/f2.i
1 r3/.hg/store/data/f1.i
1 r3/.hg/store/fncache (repofncache !)
1 r3/.hg/store/phaseroots
1 r3/.hg/store/undo
1 r3/.hg/store/undo.backupfiles
1 r3/.hg/store/undo.phaseroots
Create a non-inlined filelog in r3:
$ cd r3/d1
>>> f = open('data1', 'wb')
>>> for x in range(10000):
... f.write(b"%d\n" % x) and None
>>> f.close()
$ for j in 0 1 2 3 4 5 6 7 8 9; do
> cat data1 >> f2
> hg commit -m$j
> done
$ cd ../..
$ nlinksdir r3/.hg/store
1 r3/.hg/store/00changelog.i
1 r3/.hg/store/00manifest.i
1 r3/.hg/store/data/d1/f2.d
1 r3/.hg/store/data/d1/f2.i
1 r3/.hg/store/data/f1.i
1 r3/.hg/store/fncache (repofncache !)
1 r3/.hg/store/phaseroots
1 r3/.hg/store/undo
1 r3/.hg/store/undo.backup.fncache (repofncache !)
1 r3/.hg/store/undo.backup.phaseroots
1 r3/.hg/store/undo.backupfiles
1 r3/.hg/store/undo.phaseroots
Push to repo r1 should break up most hardlinks in r2:
$ hg -R r2 verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 2 changesets, 2 total revisions
$ cd r3
$ hg push
pushing to $TESTTMP/r1
searching for changes
adding changesets
adding manifests
adding file changes
added 10 changesets with 10 changes to 1 files
$ cd ..
$ nlinksdir r2/.hg/store
1 r2/.hg/store/00changelog.i
1 r2/.hg/store/00manifest.i
1 r2/.hg/store/data/d1/f2.i
2 r2/.hg/store/data/f1.i
[12] r2/\.hg/store/fncache (re) (repofncache !)
#if hardlink-whitelisted repofncache
$ nlinksdir r2/.hg/store/fncache
2 r2/.hg/store/fncache
#endif
$ hg -R r2 verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 2 changesets, 2 total revisions
$ cd r1
$ hg up
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Committing a change to f1 in r1 must break up hardlink f1.i in r2:
$ echo c1c1 >> f1
$ hg ci -m00
$ cd ..
$ nlinksdir r2/.hg/store
1 r2/.hg/store/00changelog.i
1 r2/.hg/store/00manifest.i
1 r2/.hg/store/data/d1/f2.i
1 r2/.hg/store/data/f1.i
[12] r2/\.hg/store/fncache (re) (repofncache !)
#if hardlink-whitelisted repofncache
$ nlinksdir r2/.hg/store/fncache
2 r2/.hg/store/fncache
#endif
Create a file which exec permissions we will change
$ cd r3
$ echo "echo hello world" > f3
$ hg add f3
$ hg ci -mf3
$ cd ..
$ cd r3
$ hg tip --template '{rev}:{node|short}\n'
12:d3b77733a28a
$ echo bla > f1
$ chmod +x f3
$ hg ci -m1
$ cd ..
Create hardlinked copy r4 of r3 (on Linux, we would call 'cp -al'):
$ linkcp r3 r4
'checklink' is produced by hardlinking a symlink, which is undefined whether
the symlink should be followed or not. It does behave differently on Linux and
BSD. Just remove it so the test pass on both platforms.
$ rm -f r4/.hg/cache/checklink
r4 has hardlinks in the working dir (not just inside .hg):
$ nlinksdir r4
2 r4/.hg/00changelog.i
2 r4/.hg/branch
2 r4/.hg/cache/branch2-base
2 r4/.hg/cache/branch2-served
2 r4/.hg/cache/checkisexec (execbit !)
? r4/.hg/cache/checklink-target (glob) (symlink !)
2 r4/.hg/cache/checknoexec (execbit !)
2 r4/.hg/cache/manifestfulltextcache
2 r4/.hg/cache/rbc-names-v1
2 r4/.hg/cache/rbc-revs-v1
2 r4/.hg/dirstate
2 r4/.hg/fsmonitor.state (fsmonitor !)
2 r4/.hg/hgrc
2 r4/.hg/last-message.txt
2 r4/.hg/requires
2 r4/.hg/store/00changelog.i
2 r4/.hg/store/00manifest.i
2 r4/.hg/store/data/d1/f2.d
2 r4/.hg/store/data/d1/f2.i
2 r4/.hg/store/data/f1.i
2 r4/.hg/store/data/f3.i
2 r4/.hg/store/fncache (repofncache !)
2 r4/.hg/store/phaseroots
2 r4/.hg/store/undo
2 r4/.hg/store/undo.backup.fncache (repofncache !)
2 r4/.hg/store/undo.backup.phaseroots
2 r4/.hg/store/undo.backupfiles
2 r4/.hg/store/undo.phaseroots
[24] r4/\.hg/undo\.backup\.dirstate (re)
2 r4/.hg/undo.bookmarks
2 r4/.hg/undo.branch
2 r4/.hg/undo.desc
[24] r4/\.hg/undo\.dirstate (re)
2 r4/d1/data1
2 r4/d1/f2
2 r4/f1
2 r4/f3
Update back to revision 12 in r4 should break hardlink of file f1 and f3:
#if hardlink-whitelisted
$ nlinksdir r4/.hg/undo.backup.dirstate r4/.hg/undo.dirstate
4 r4/.hg/undo.backup.dirstate
4 r4/.hg/undo.dirstate
#endif
$ hg -R r4 up 12
2 files updated, 0 files merged, 0 files removed, 0 files unresolved (execbit !)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-execbit !)
$ nlinksdir r4
2 r4/.hg/00changelog.i
1 r4/.hg/branch
2 r4/.hg/cache/branch2-base
2 r4/.hg/cache/branch2-served
2 r4/.hg/cache/checkisexec (execbit !)
2 r4/.hg/cache/checklink-target (symlink !)
2 r4/.hg/cache/checknoexec (execbit !)
2 r4/.hg/cache/manifestfulltextcache
2 r4/.hg/cache/rbc-names-v1
2 r4/.hg/cache/rbc-revs-v1
1 r4/.hg/dirstate
1 r4/.hg/fsmonitor.state (fsmonitor !)
2 r4/.hg/hgrc
2 r4/.hg/last-message.txt
2 r4/.hg/requires
2 r4/.hg/store/00changelog.i
2 r4/.hg/store/00manifest.i
2 r4/.hg/store/data/d1/f2.d
2 r4/.hg/store/data/d1/f2.i
2 r4/.hg/store/data/f1.i
2 r4/.hg/store/data/f3.i
2 r4/.hg/store/fncache
2 r4/.hg/store/phaseroots
2 r4/.hg/store/undo
2 r4/.hg/store/undo.backup.fncache (repofncache !)
2 r4/.hg/store/undo.backup.phaseroots
2 r4/.hg/store/undo.backupfiles
2 r4/.hg/store/undo.phaseroots
[24] r4/\.hg/undo\.backup\.dirstate (re)
2 r4/.hg/undo.bookmarks
2 r4/.hg/undo.branch
2 r4/.hg/undo.desc
[24] r4/\.hg/undo\.dirstate (re)
2 r4/d1/data1
2 r4/d1/f2
1 r4/f1
1 r4/f3 (execbit !)
2 r4/f3 (no-execbit !)
#if hardlink-whitelisted
$ nlinksdir r4/.hg/undo.backup.dirstate r4/.hg/undo.dirstate
4 r4/.hg/undo.backup.dirstate
4 r4/.hg/undo.dirstate
#endif
Test hardlinking outside hg:
$ mkdir x
$ echo foo > x/a
$ linkcp x y
$ echo bar >> y/a
No diff if hardlink:
$ diff x/a y/a
Test mq hardlinking:
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init a
$ cd a
$ hg qimport -n foo - << EOF
> # HG changeset patch
> # Date 1 0
> diff -r 2588a8b53d66 a
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/a Wed Jul 23 15:54:29 2008 +0200
> @@ -0,0 +1,1 @@
> +a
> EOF
adding foo to series file
$ hg qpush
applying foo
now at: foo
$ cd ..
$ linkcp a b
$ cd b
$ hg qimport -n bar - << EOF
> # HG changeset patch
> # Date 2 0
> diff -r 2588a8b53d66 a
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/b Wed Jul 23 15:54:29 2008 +0200
> @@ -0,0 +1,1 @@
> +b
> EOF
adding bar to series file
$ hg qpush
applying bar
now at: bar
$ cat .hg/patches/status
430ed4828a74fa4047bc816a25500f7472ab4bfe:foo
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c:bar
$ cat .hg/patches/series
foo
bar
$ cat ../a/.hg/patches/status
430ed4828a74fa4047bc816a25500f7472ab4bfe:foo
$ cat ../a/.hg/patches/series
foo
Test tags hardlinking:
$ hg qdel -r qbase:qtip
patch foo finalized without changeset message
patch bar finalized without changeset message
$ hg tag -l lfoo
$ hg tag foo
$ cd ..
$ linkcp b c
$ cd c
$ hg tag -l -r 0 lbar
$ hg tag -r 0 bar
$ cat .hgtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo
430ed4828a74fa4047bc816a25500f7472ab4bfe bar
$ cat .hg/localtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo
430ed4828a74fa4047bc816a25500f7472ab4bfe lbar
$ cat ../b/.hgtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo
$ cat ../b/.hg/localtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo
$ cd ..