match: convert O(n) to O(log n) in exactmatcher.visitchildrenset
When using narrow, during rebase this is called (at least) once per directory in
the set of files in the commit being rebased. Every time it's called, we did the
set arithmetic (now extracted and cached), which was probably pretty cheap but
not necessary to repeat each time, looped over every item in the matcher and
kept things that started with the directory we were querying.
With very large narrowspecs, and a commit that touched a file in a large number
of directories, this was slow. In a pathological repo, the rebase of a single
commit (that touched over 17k files, I believe in approximately as many
directories) with a narrowspec that had >32k entries took 8,246s of profiled
time, with 5,007s of that spent in visitchildrenset (transitively). With this
change, the time spent in visitchildrenset is less than 34s (which is where my
profile cut off). Most of the remaining time was network access due to our
custom remotefilelog-based setup not properly prefetching.
Differential Revision: https://phab.mercurial-scm.org/D10294
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> EOF
$ echo x > x
$ echo z > z
$ hg commit -qAm x
$ echo x2 > x
$ echo y > y
$ hg commit -qAm y
$ hg bookmark foo
$ cd ..
# prefetch a revision
$ hgcloneshallow ssh://user@dummy/master shallow --noupdate
streaming all changes
2 files to transfer, 528 bytes of data
transferred 528 bytes in * seconds (*/sec) (glob)
searching for changes
no changes found
$ cd shallow
$ hg prefetch -r 0
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 0 x
x
# prefetch with base
$ clearcache
$ hg prefetch -r 0::1 -b 0
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 1 x
x2
$ hg cat -r 1 y
y
$ hg cat -r 0 x
x
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 0 z
z
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ hg prefetch -r 0::1 --base 0
$ hg prefetch -r 0::1 -b 1
$ hg prefetch -r 0::1
# prefetch a range of revisions
$ clearcache
$ hg prefetch -r 0::1
4 files fetched over 1 fetches - (4 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 0 x
x
$ hg cat -r 1 x
x2
# prefetch certain files
$ clearcache
$ hg prefetch -r 1 x
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 1 x
x2
$ hg cat -r 1 y
y
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
# prefetch on pull when configured
$ printf "[remotefilelog]\npullprefetch=bookmark()\n" >> .hg/hgrc
$ hg strip tip
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/109c3a557a73-3f43405e-backup.hg (glob)
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ clearcache
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 109c3a557a73
(run 'hg update' to get a working copy)
prefetching file contents
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
$ hg up tip
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
# prefetch only fetches changes not in working copy
$ hg strip tip
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/109c3a557a73-3f43405e-backup.hg (glob)
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ clearcache
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 109c3a557a73
(run 'hg update' to get a working copy)
prefetching file contents
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
# Make some local commits that produce the same file versions as are on the
# server. To simulate a situation where we have local commits that were somehow
# pushed, and we will soon pull.
$ hg prefetch -r 'all()'
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ hg strip -q -r 0
$ echo x > x
$ echo z > z
$ hg commit -qAm x
$ echo x2 > x
$ echo y > y
$ hg commit -qAm y
# prefetch server versions, even if local versions are available
$ clearcache
$ hg strip -q tip
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 109c3a557a73
1 local changesets published (?)
(run 'hg update' to get a working copy)
prefetching file contents
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ cd ..
# Prefetch unknown files during checkout
$ hgcloneshallow ssh://user@dummy/master shallow2
streaming all changes
2 files to transfer, 528 bytes of data
transferred 528 bytes in * seconds * (glob)
searching for changes
no changes found
updating to branch default
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over * (glob)
$ cd shallow2
$ hg up -q null
$ echo x > x
$ echo y > y
$ echo z > z
$ clearcache
$ hg up tip
x: untracked file differs
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over * (glob)
abort: untracked files in working directory differ from files in requested revision
[20]
$ hg revert --all
# Test batch fetching of lookup files during hg status
$ hg up --clean tip
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg debugrebuilddirstate
$ clearcache
$ hg status
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over * (glob)
# Prefetch during addrename detection
$ hg up -q --clean tip
$ hg revert --all
$ mv x x2
$ mv y y2
$ mv z z2
$ echo a > a
$ hg add a
$ rm a
$ clearcache
$ hg addremove -s 50 > /dev/null
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over * (glob)
$ hg revert --all
forgetting x2
forgetting y2
forgetting z2
undeleting x
undeleting y
undeleting z
# Revert across double renames. Note: the scary "abort", error is because
# https://bz.mercurial-scm.org/5419 .
$ cd ../master
$ hg mv z z2
$ hg commit -m 'move z -> z2'
$ cd ../shallow2
$ hg pull -q
$ clearcache
$ hg mv y y2
y2: not overwriting - file exists
('hg rename --after' to record the rename)
[1]
$ hg mv x x2
x2: not overwriting - file exists
('hg rename --after' to record the rename)
[1]
$ hg mv z2 z3
z2: not copying - file is not managed
abort: no files to copy
[10]
$ find $CACHEDIR -type f | sort
.. The following output line about files fetches is globed because it is
.. flaky, the core the test is checked when checking the cache dir, so
.. hopefully this flakyness is not hiding any actual bug.
$ hg revert -a -r 1 || true
? files fetched over 1 fetches - (? misses, 0.00% hit ratio) over * (glob)
abort: z2@109c3a557a73: not found in manifest (?)
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/ef95c5376f34698742fe34f315fd82136f8f68c0
$TESTTMP/hgcache/master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a
$TESTTMP/hgcache/master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
$TESTTMP/hgcache/repos
# warning when we have excess remotefilelog fetching
$ cat > repeated_fetch.py << EOF
> import binascii
> from mercurial import extensions, registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command(b'repeated-fetch', [], b'', inferrepo=True)
> def repeated_fetch(ui, repo, *args, **opts):
> for i in range(20):
> try:
> hexid = (b'%02x' % (i + 1)) * 20
> repo.fileservice.prefetch([(b'somefile.txt', hexid)])
> except Exception:
> pass
> EOF
We should only output to the user once. We're ignoring most of the output
because we're not actually fetching anything real here, all the hashes are
bogus, so it's just going to be errors and a final summary of all the misses.
$ hg --config extensions.repeated_fetch=repeated_fetch.py \
> --config remotefilelog.fetchwarning="fetch warning!" \
> --config extensions.blackbox= \
> repeated-fetch 2>&1 | grep 'fetch warning'
fetch warning!
We should output to blackbox three times, with a stack trace on each (though
that isn't tested here).
$ grep 'excess remotefilelog fetching' .hg/blackbox.log
.* excess remotefilelog fetching: (re)
.* excess remotefilelog fetching: (re)
.* excess remotefilelog fetching: (re)