view tests/test-fncache.t @ 29375:fcaf20175b1b

demandimport: delay loading for "from a import b" with absolute_import

Before this patch, "from a import b" doesn't delay loading module "b",
if absolute_import is enabled, even though "from . import b" does.

For example:

  - it is assumed that extension X has "from P import M" for module M
    under package P with absolute_import feature

  - if importing module M is already delayed before loading extension
    X, loading module M in extension X is delayed until actually
    referring

    util, cmdutil, scmutil or so of Mercurial itself should be
    imported by "from . import M" style before loading extension X

  - otherwise, module M is loaded immediately at loading extension X,
    even if extension X itself isn't used at that "hg" command invocation

    Some minor modules (e.g. filemerge or so) of Mercurial itself
    aren't imported by "from . import M" style before loading
    extension X. And of course, external libraries aren't, too.

This might cause startup performance problem of hg command, because
many bundled extensions already enable absolute_import feature.

To delay loading module for "from a import b" with absolute_import
feature, this patch does below in "from a (or .a) import b" with
absolute_import case:

  1. import root module of "name" by system built-in __import__
     (referred as _origimport)

  2. recurse down the module chain for hierarchical "name"

     This logic can be shared with non absolute_import
     case. Therefore, this patch also centralizes it into chainmodules().

  3. and fall through to process elements in "fromlist" for the leaf
     module of "name"

     Processing elements in "fromlist" is executed in the code path
     after "if _pypy: .... else: ..." clause. Therefore, this patch
     replaces "if _pypy:" with "elif _pypy:" to share it.

At 4f1144c3c72b introducing original "work around" for "from a import
b" case, elements in "fromlist" were imported with "level=level". But
"level" might be grater than 1 (e.g. level=2 in "from .. import b"
case) at demandimport() invocation, and importing direct sub-module in
"fromlist" with level grater than 1 causes unexpected result.

IMHO, this seems main reason of "errors for unknown reason" described
in 4f1144c3c72b, and we don't have to worry about it, because this
issue was already fixed by 78d05778907b.

This is reason why this patch removes "errors for unknown reasons"
comment.

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 (glob)
  $ 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 (glob)
  $ 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/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/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
  > import os
  > from mercurial import commands, error
  > from mercurial.extensions import wrapcommand, wrapfunction
  > 
  > 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):
  >     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):
  >     wrapcommand(commands.table, "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
  > import os
  > from mercurial import commands, error, localrepo
  > from mercurial.extensions import wrapfunction
  > 
  > def wrapper(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 uisetup(ui):
  >     wrapfunction(localrepo.localrepository, 'transaction', wrapper)
  > 
  > cmdtable = {}
  > 
  > EOF
  $ rm -f "${extpath}c"
  $ 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
  > import os
  > from mercurial import commands, error, transaction, localrepo
  > from mercurial.extensions import wrapfunction
  > 
  > 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):
  >     wrapfunction(localrepo.localrepository, 'transaction', trwrapper)
  >     wrapfunction(transaction.transaction, '_abort', abortwrapper)
  > 
  > cmdtable = {}
  > 
  > EOF
  $ rm -f "${extpath}c"
  $ 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