debugcommands: introduce actions to perform deterministic reads
"readavailable" is useful as a debugging device to see what data is
available on a pipe. But the mechanism isn't deterministic because
what's available on a pipe is highly conditional on timing, system
load, OS behavior, etc. This makes it not suitable for tests.
We introduce "ereadline," "read," and "eread" for performing
deterministic I/O operations (at least on blocking file descriptors).
We stop short of converting existing consumers of "readavailable"
in tests because we're working out race conditions and deadlocks
on Windows. But the goal is to eventually move tests away from
"readavailable" to these new APIs.
Differential Revision: https://phab.mercurial-scm.org/D2720
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
3 files, 3 changesets, 3 total revisions
$ 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!
3 files, 3 changesets, 3 total revisions
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
3 files, 3 changesets, 3 total revisions
$ 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
$ 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
$ 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("forced transaction failure")
> # zzz prefix to ensure it sorted after store.write
> tr.addfinalize('zzz-forcefails', fail)
> return tr
>
> def abortwrapper(orig, self, *args, **kwargs):
> raise error.Abort("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
1 files, 1 changesets, 1 total revisions
$ 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
$ 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