dirstate: when calling rebuild(), avoid some N^2 codepaths
I had a user repo with 200k files in it. Calling `hg debugrebuilddirstate` took
tens of minutes (I didn't wait for it). In that situation,
changedfiles==allfiles, and both are lists. This meant that we had to run an
average of 100k comparisons, for each of 200k files, just to check whether a
file needed to have normallookup called (it always did), or drop.
While it's probably not a huge issue, in my very awkward synthetic benchmark I
wrote (not using a benchmark library or anything), I was seeing some slowdowns
for small-changedfiles and very-large-allfiles invocations, with an inflection
somewhere around 10 items in changedfiles (regardless of the size of allfiles);
above 10 items in changedfiles, the new code appears to always be faster. For
the case of 50k files in changedfiles and the same items in allfiles, I'm seeing
differences of 15s of just running comparisons vs. 0.003793s. I haven't bothered
to run a comparison of 200k items in changedfiles and allfiles. :)
Differential Revision: https://phab.mercurial-scm.org/D7665
#require repofncache
An extension which will set fncache chunksize to 1 byte to make sure that logic
does not break
$ cat > chunksize.py <<EOF
> from __future__ import absolute_import
> from mercurial import store
> store.fncache_chunksize = 1
> EOF
$ cat >> $HGRCPATH <<EOF
> [extensions]
> chunksize = $TESTTMP/chunksize.py
> EOF
Init repo1:
$ hg init repo1
$ cd repo1
$ echo "some text" > a
$ hg add
adding a
$ hg ci -m first
$ cat .hg/store/fncache | sort
data/a.i
Testing a.i/b:
$ mkdir a.i
$ echo "some other text" > a.i/b
$ hg add
adding a.i/b
$ hg ci -m second
$ cat .hg/store/fncache | sort
data/a.i
data/a.i.hg/b.i
Testing a.i.hg/c:
$ mkdir a.i.hg
$ echo "yet another text" > a.i.hg/c
$ hg add
adding a.i.hg/c
$ hg ci -m third
$ cat .hg/store/fncache | sort
data/a.i
data/a.i.hg.hg/c.i
data/a.i.hg/b.i
Testing verify:
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 3 changesets with 3 changes to 3 files
$ rm .hg/store/fncache
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
warning: revlog 'data/a.i' not in fncache!
warning: revlog 'data/a.i.hg/c.i' not in fncache!
warning: revlog 'data/a.i/b.i' not in fncache!
checked 3 changesets with 3 changes to 3 files
3 warnings encountered!
hint: run "hg debugrebuildfncache" to recover from corrupt fncache
Follow the hint to make sure it works
$ hg debugrebuildfncache
adding data/a.i
adding data/a.i.hg/c.i
adding data/a.i/b.i
3 items added, 0 removed from fncache
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 3 changesets with 3 changes to 3 files
$ cd ..
Non store repo:
$ hg --config format.usestore=False init foo
$ cd foo
$ mkdir tst.d
$ echo foo > tst.d/foo
$ hg ci -Amfoo
adding tst.d/foo
$ find .hg | sort
.hg
.hg/00changelog.i
.hg/00manifest.i
.hg/cache
.hg/cache/branch2-served
.hg/cache/rbc-names-v1
.hg/cache/rbc-revs-v1
.hg/data
.hg/data/tst.d.hg
.hg/data/tst.d.hg/foo.i
.hg/dirstate
.hg/fsmonitor.state (fsmonitor !)
.hg/last-message.txt
.hg/phaseroots
.hg/requires
.hg/undo
.hg/undo.backup.dirstate
.hg/undo.backupfiles
.hg/undo.bookmarks
.hg/undo.branch
.hg/undo.desc
.hg/undo.dirstate
.hg/undo.phaseroots
.hg/wcache
.hg/wcache/checkisexec (execbit !)
.hg/wcache/checklink (symlink !)
.hg/wcache/checklink-target (symlink !)
.hg/wcache/manifestfulltextcache (reporevlogstore !)
$ cd ..
Non fncache repo:
$ hg --config format.usefncache=False init bar
$ cd bar
$ mkdir tst.d
$ echo foo > tst.d/Foo
$ hg ci -Amfoo
adding tst.d/Foo
$ find .hg | sort
.hg
.hg/00changelog.i
.hg/cache
.hg/cache/branch2-served
.hg/cache/rbc-names-v1
.hg/cache/rbc-revs-v1
.hg/dirstate
.hg/fsmonitor.state (fsmonitor !)
.hg/last-message.txt
.hg/requires
.hg/store
.hg/store/00changelog.i
.hg/store/00manifest.i
.hg/store/data
.hg/store/data/tst.d.hg
.hg/store/data/tst.d.hg/_foo.i
.hg/store/phaseroots
.hg/store/undo
.hg/store/undo.backupfiles
.hg/store/undo.phaseroots
.hg/undo.backup.dirstate
.hg/undo.bookmarks
.hg/undo.branch
.hg/undo.desc
.hg/undo.dirstate
.hg/wcache
.hg/wcache/checkisexec (execbit !)
.hg/wcache/checklink (symlink !)
.hg/wcache/checklink-target (symlink !)
.hg/wcache/manifestfulltextcache (reporevlogstore !)
$ cd ..
Encoding of reserved / long paths in the store
$ hg init r2
$ cd r2
$ cat <<EOF > .hg/hgrc
> [ui]
> portablefilenames = ignore
> EOF
$ hg import -q --bypass - <<EOF
> # HG changeset patch
> # User test
> # Date 0 0
> # Node ID 1c7a2f7cb77be1a0def34e4c7cabc562ad98fbd7
> # Parent 0000000000000000000000000000000000000000
> 1
>
> diff --git a/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-123456789-12.3456789-12345-ABCDEFGHIJKLMNOPRSTUVWXYZ-abcdefghjiklmnopqrstuvwxyz b/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-123456789-12.3456789-12345-ABCDEFGHIJKLMNOPRSTUVWXYZ-abcdefghjiklmnopqrstuvwxyz
> new file mode 100644
> --- /dev/null
> +++ b/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-123456789-12.3456789-12345-ABCDEFGHIJKLMNOPRSTUVWXYZ-abcdefghjiklmnopqrstuvwxyz
> @@ -0,0 +1,1 @@
> +foo
> diff --git a/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT b/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT
> new file mode 100644
> --- /dev/null
> +++ b/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT
> @@ -0,0 +1,1 @@
> +foo
> diff --git a/Project Planning/Resources/AnotherLongDirectoryName/Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt b/Project Planning/Resources/AnotherLongDirectoryName/Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt
> new file mode 100644
> --- /dev/null
> +++ b/Project Planning/Resources/AnotherLongDirectoryName/Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt
> @@ -0,0 +1,1 @@
> +foo
> diff --git a/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c b/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c
> new file mode 100644
> --- /dev/null
> +++ b/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c
> @@ -0,0 +1,1 @@
> +foo
> diff --git a/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider b/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider
> new file mode 100644
> --- /dev/null
> +++ b/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider
> @@ -0,0 +1,1 @@
> +foo
> EOF
$ find .hg/store -name *.i | sort
.hg/store/00changelog.i
.hg/store/00manifest.i
.hg/store/data/bla.aux/pr~6e/_p_r_n/lpt/co~6d3/nu~6c/coma/foo._n_u_l/normal.c.i
.hg/store/dh/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxx168e07b38e65eff86ab579afaaa8e30bfbe0f35f.i
.hg/store/dh/au~78/second/x.prn/fourth/fi~3afth/sixth/seventh/eighth/nineth/tenth/loremia20419e358ddff1bf8751e38288aff1d7c32ec05.i
.hg/store/dh/enterpri/openesba/contrib-/corba-bc/netbeans/wsdlexte/src/main/java/org.net7018f27961fdf338a598a40c4683429e7ffb9743.i
.hg/store/dh/project_/resource/anotherl/followed/andanoth/andthenanextremelylongfilename0d8e1f4187c650e2f1fdca9fd90f786bc0976b6b.i
$ cd ..
Aborting lock does not prevent fncache writes
$ cat > exceptionext.py <<EOF
> from __future__ import absolute_import
> import os
> from mercurial import commands, error, extensions
>
> def lockexception(orig, vfs, lockname, wait, releasefn, *args, **kwargs):
> def releasewrap():
> l.held = False # ensure __del__ is a noop
> raise error.Abort("forced lock failure")
> l = orig(vfs, lockname, wait, releasewrap, *args, **kwargs)
> return l
>
> def reposetup(ui, repo):
> extensions.wrapfunction(repo, '_lock', lockexception)
>
> cmdtable = {}
>
> # wrap "commit" command to prevent wlock from being '__del__()'-ed
> # at the end of dispatching (for intentional "forced lcok failure")
> def commitwrap(orig, ui, repo, *pats, **opts):
> repo = repo.unfiltered() # to use replaced repo._lock certainly
> wlock = repo.wlock()
> try:
> return orig(ui, repo, *pats, **opts)
> finally:
> # multiple 'relase()' is needed for complete releasing wlock,
> # because "forced" abort at last releasing store lock
> # prevents wlock from being released at same 'lockmod.release()'
> for i in range(wlock.held):
> wlock.release()
>
> def extsetup(ui):
> extensions.wrapcommand(commands.table, b"commit", commitwrap)
> EOF
$ extpath=`pwd`/exceptionext.py
$ hg init fncachetxn
$ cd fncachetxn
$ printf "[extensions]\nexceptionext=$extpath\n" >> .hg/hgrc
$ touch y
$ hg ci -qAm y
abort: forced lock failure
[255]
$ cat .hg/store/fncache
data/y.i
Aborting transaction prevents fncache change
$ cat > ../exceptionext.py <<EOF
> from __future__ import absolute_import
> import os
> from mercurial import commands, error, extensions, localrepo
>
> def wrapper(orig, self, *args, **kwargs):
> tr = orig(self, *args, **kwargs)
> def fail(tr):
> raise error.Abort(b"forced transaction failure")
> # zzz prefix to ensure it sorted after store.write
> tr.addfinalize(b'zzz-forcefails', fail)
> return tr
>
> def uisetup(ui):
> extensions.wrapfunction(
> localrepo.localrepository, b'transaction', wrapper)
>
> cmdtable = {}
>
> EOF
Clean cached version
$ rm -f "${extpath}c"
$ rm -Rf "`dirname $extpath`/__pycache__"
$ touch z
$ hg ci -qAm z
transaction abort!
rollback completed
abort: forced transaction failure
[255]
$ cat .hg/store/fncache
data/y.i
Aborted transactions can be recovered later
$ cat > ../exceptionext.py <<EOF
> from __future__ import absolute_import
> import os
> from mercurial import (
> commands,
> error,
> extensions,
> localrepo,
> transaction,
> )
>
> def trwrapper(orig, self, *args, **kwargs):
> tr = orig(self, *args, **kwargs)
> def fail(tr):
> raise error.Abort(b"forced transaction failure")
> # zzz prefix to ensure it sorted after store.write
> tr.addfinalize(b'zzz-forcefails', fail)
> return tr
>
> def abortwrapper(orig, self, *args, **kwargs):
> raise error.Abort(b"forced transaction failure")
>
> def uisetup(ui):
> extensions.wrapfunction(localrepo.localrepository, 'transaction',
> trwrapper)
> extensions.wrapfunction(transaction.transaction, '_abort',
> abortwrapper)
>
> cmdtable = {}
>
> EOF
Clean cached versions
$ rm -f "${extpath}c"
$ rm -Rf "`dirname $extpath`/__pycache__"
$ hg up -q 1
$ touch z
$ hg ci -qAm z 2>/dev/null
[255]
$ cat .hg/store/fncache | sort
data/y.i
data/z.i
$ hg recover
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ cat .hg/store/fncache
data/y.i
$ cd ..
debugrebuildfncache does nothing unless repo has fncache requirement
$ hg --config format.usefncache=false init nofncache
$ cd nofncache
$ hg debugrebuildfncache
(not rebuilding fncache because repository does not support fncache)
$ cd ..
debugrebuildfncache works on empty repository
$ hg init empty
$ cd empty
$ hg debugrebuildfncache
fncache already up to date
$ cd ..
debugrebuildfncache on an up to date repository no-ops
$ hg init repo
$ cd repo
$ echo initial > foo
$ echo initial > .bar
$ hg commit -A -m initial
adding .bar
adding foo
$ cat .hg/store/fncache | sort
data/.bar.i
data/foo.i
$ hg debugrebuildfncache
fncache already up to date
debugrebuildfncache restores deleted fncache file
$ rm -f .hg/store/fncache
$ hg debugrebuildfncache
adding data/.bar.i
adding data/foo.i
2 items added, 0 removed from fncache
$ cat .hg/store/fncache | sort
data/.bar.i
data/foo.i
Rebuild after rebuild should no-op
$ hg debugrebuildfncache
fncache already up to date
A single missing file should get restored, an extra file should be removed
$ cat > .hg/store/fncache << EOF
> data/foo.i
> data/bad-entry.i
> EOF
$ hg debugrebuildfncache
removing data/bad-entry.i
adding data/.bar.i
1 items added, 1 removed from fncache
$ cat .hg/store/fncache | sort
data/.bar.i
data/foo.i
debugrebuildfncache recovers from truncated line in fncache
$ printf a > .hg/store/fncache
$ hg debugrebuildfncache
fncache does not ends with a newline
adding data/.bar.i
adding data/foo.i
2 items added, 0 removed from fncache
$ cat .hg/store/fncache | sort
data/.bar.i
data/foo.i
$ cd ..
Try a simple variation without dotencode to ensure fncache is ignorant of encoding
$ hg --config format.dotencode=false init nodotencode
$ cd nodotencode
$ echo initial > foo
$ echo initial > .bar
$ hg commit -A -m initial
adding .bar
adding foo
$ cat .hg/store/fncache | sort
data/.bar.i
data/foo.i
$ rm .hg/store/fncache
$ hg debugrebuildfncache
adding data/.bar.i
adding data/foo.i
2 items added, 0 removed from fncache
$ cat .hg/store/fncache | sort
data/.bar.i
data/foo.i
$ cd ..
In repositories that have accumulated a large number of files over time, the
fncache file is going to be large. If we possibly can avoid loading it, so much the better.
The cache should not loaded when committing changes to existing files, or when unbundling
changesets that only contain changes to existing files:
$ cat > fncacheloadwarn.py << EOF
> from __future__ import absolute_import
> from mercurial import extensions, localrepo
>
> def extsetup(ui):
> def wrapstore(orig, requirements, *args):
> store = orig(requirements, *args)
> if b'store' in requirements and b'fncache' in requirements:
> instrumentfncachestore(store, ui)
> return store
> extensions.wrapfunction(localrepo, 'makestore', wrapstore)
>
> def instrumentfncachestore(fncachestore, ui):
> class instrumentedfncache(type(fncachestore.fncache)):
> def _load(self):
> ui.warn(b'fncache load triggered!\n')
> super(instrumentedfncache, self)._load()
> fncachestore.fncache.__class__ = instrumentedfncache
> EOF
$ fncachextpath=`pwd`/fncacheloadwarn.py
$ hg init nofncacheload
$ cd nofncacheload
$ printf "[extensions]\nfncacheloadwarn=$fncachextpath\n" >> .hg/hgrc
A new file should trigger a load, as we'd want to update the fncache set in that case:
$ touch foo
$ hg ci -qAm foo
fncache load triggered!
But modifying that file should not:
$ echo bar >> foo
$ hg ci -qm foo
If a transaction has been aborted, the zero-size truncated index file will
not prevent the fncache from being loaded; rather than actually abort
a transaction, we simulate the situation by creating a zero-size index file:
$ touch .hg/store/data/bar.i
$ touch bar
$ hg ci -qAm bar
fncache load triggered!
Unbundling should follow the same rules; existing files should not cause a load:
$ hg clone -q . tobundle
$ echo 'new line' > tobundle/bar
$ hg -R tobundle ci -qm bar
$ hg -R tobundle bundle -q barupdated.hg
$ hg unbundle -q barupdated.hg
but adding new files should:
$ touch tobundle/newfile
$ hg -R tobundle ci -qAm newfile
$ hg -R tobundle bundle -q newfile.hg
$ hg unbundle -q newfile.hg
fncache load triggered!
$ cd ..