view tests/test-convert-tla.t @ 30446:b324b4e431e5

posix: give checkexec a fast path; keep the check files and test read only

Before, Mercurial would create a new temporary file every time, stat it, change
its exec mode, stat it again, and delete it. Most of this dance was done to
handle the rare and not-so-essential case of VFAT mounts on unix. The cost of
that was paid by the much more common and important case of using normal file
systems.

Instead, try to create and preserve .hg/cache/checkisexec and
.hg/cache/checknoexec with and without exec flag set. If the files exist and
have correct exec flags set, we can conclude that that file system supports the
exec flag. Best case, the whole exec check can thus be done with two stat
calls. Worst case, we delete the wrong files and check as usual. That will be
because temporary loss of exec bit or on file systems without support for the
exec bit. In that case we check as we did before, with the additional overhead
of one extra stat call.

It is possible that this different test algorithm in some cases on odd file
systems will give different behaviour. Again, I think it will be rare and
special cases and I think it is worth the risk.

test-clone.t happens to show the situation where checkisexec is left behind
from the old style check, while checknoexec only will be created next time a
exec check will be performed.

#require tla symlink

  $ tla my-id "mercurial <[e-mail]>"
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert=" >> $HGRCPATH

create tla archive

  $ tla make-archive tla@mercurial--convert `pwd`/hg-test-convert-tla

initialize tla repo

  $ mkdir tla-repo
  $ cd tla-repo/
  $ tla init-tree tla@mercurial--convert/tla--test--0
  $ tla import
  * creating version tla@mercurial--convert/tla--test--0
  * imported tla@mercurial--convert/tla--test--0

create initial files

  $ echo 'this is a file' > a
  $ tla add a
  $ mkdir src
  $ tla add src
  $ cd src
  $ dd count=1 if=/dev/zero of=b > /dev/null 2> /dev/null
  $ tla add b
  $ tla commit -s "added a file, src and src/b (binary)"
  A/ .arch-ids
  A/ src
  A/ src/.arch-ids
  A  .arch-ids/a.id
  A  a
  A  src/.arch-ids/=id
  A  src/.arch-ids/b.id
  A  src/b
  * update pristine tree (tla@mercurial--convert/tla--test--0--base-0 => tla--test--0--patch-1)
  * committed tla@mercurial--convert/tla--test--0--patch-1

create link file and modify a

  $ ln -s ../a a-link
  $ tla add a-link
  $ echo 'this a modification to a' >> ../a
  $ tla commit -s "added link to a and modify a"
  A  src/.arch-ids/a-link.id
  A  src/a-link
  M  a
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-1 => tla--test--0--patch-2)
  * committed tla@mercurial--convert/tla--test--0--patch-2

create second link and modify b

  $ ln -s ../a a-link-2
  $ tla add a-link-2
  $ dd count=1 seek=1 if=/dev/zero of=b > /dev/null 2> /dev/null
  $ tla commit -s "added second link and modify b"
  A  src/.arch-ids/a-link-2.id
  A  src/a-link-2
  Mb src/b
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-2 => tla--test--0--patch-3)
  * committed tla@mercurial--convert/tla--test--0--patch-3

b file to link and a-link-2 to regular file

  $ rm -f a-link-2
  $ echo 'this is now a regular file' > a-link-2
  $ ln -sf ../a b
  $ tla commit -s "file to link and link to file test"
  fl src/b
  lf src/a-link-2
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-3 => tla--test--0--patch-4)
  * committed tla@mercurial--convert/tla--test--0--patch-4

move a-link-2 file and src directory

  $ cd ..
  $ tla mv src/a-link-2 c
  $ tla mv src test
  $ tla commit -s "move and rename a-link-2 file and src directory"
  D/ src/.arch-ids
  A/ test/.arch-ids
  /> src	test
  => src/.arch-ids/a-link-2.id	.arch-ids/c.id
  => src/a-link-2	c
  => src/.arch-ids/=id	test/.arch-ids/=id
  => src/.arch-ids/a-link.id	test/.arch-ids/a-link.id
  => src/.arch-ids/b.id	test/.arch-ids/b.id
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-4 => tla--test--0--patch-5)
  * committed tla@mercurial--convert/tla--test--0--patch-5
  $ cd ..

converting tla repo to Mercurial

  $ hg convert tla-repo tla-repo-hg
  initializing destination tla-repo-hg repository
  analyzing tree version tla@mercurial--convert/tla--test--0...
  scanning source...
  sorting...
  converting...
  5 initial import
  4 added a file, src and src/b (binary)
  3 added link to a and modify a
  2 added second link and modify b
  1 file to link and link to file test
  0 move and rename a-link-2 file and src directory
  $ tla register-archive -d tla@mercurial--convert
  $ glog()
  > {
  >     hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@"
  > }

show graph log

  $ glog -R tla-repo-hg
  o  5 "move and rename a-link-2 file and src directory" files: c src/a-link src/a-link-2 src/b test/a-link test/b
  |
  o  4 "file to link and link to file test" files: src/a-link-2 src/b
  |
  o  3 "added second link and modify b" files: src/a-link-2 src/b
  |
  o  2 "added link to a and modify a" files: a src/a-link
  |
  o  1 "added a file, src and src/b (binary)" files: a src/b
  |
  o  0 "initial import" files:
  
  $ hg up -q -R tla-repo-hg
  $ hg -R tla-repo-hg manifest --debug
  c4072c4b72e1cabace081888efa148ee80ca3cbb 644   a
  0201ac32a3a8e86e303dff60366382a54b48a72e 644   c
  c0067ba5ff0b7c9a3eb17270839d04614c435623 644 @ test/a-link
  375f4263d86feacdea7e3c27100abd1560f2a973 644 @ test/b