tests/test-relink.t

treemanifest: optimize treemanifest._walk() to skip directories

This makes treemanifest.walk() not visit submanifests that are known not to
have any matching files. It does this by calling match.visitdir() on
submanifests as it walks.

This change also updates largefiles to be able to work with this new behavior
in treemanifests. It overrides match.visitdir(), the function that dictates
how walk() and matches() skip over directories.

The greatest speed improvements are seen with narrower scopes. For example,
this commit speeds up the following command on the Mozilla repo from 1.14s
to 1.02s:
  hg files -r . dom/apps/

Whereas with a wider scope, dom/, the speed only improves from 1.21s to 1.13s.

As with similar a similar optimization to treemanifest.matches(), this change
will bring out even bigger performance improvements once treemanifests are
loaded lazily. Once that happens, we won't just skip over looking at
submanifests, but we'll skip even loading them.

#require hardlink

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "relink=" >> $HGRCPATH

  $ fix_path() {
  >     tr '\\' /
  > }

  $ cat > arelinked.py <<EOF
  > import sys, os
  > from mercurial import util
  > path1, path2 = sys.argv[1:3]
  > if util.samefile(path1, path2):
  >     print '%s == %s' % (path1, path2)
  > else:
  >     print '%s != %s' % (path1, path2)
  > EOF


create source repository

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ echo b > b
  $ hg ci -Am addfile
  adding a
  adding b
  $ cat "$TESTDIR/binfile.bin" >> a
  $ cat "$TESTDIR/binfile.bin" >> b
  $ hg ci -Am changefiles

make another commit to create files larger than 1 KB to test
formatting of final byte count

  $ cat "$TESTDIR/binfile.bin" >> a
  $ cat "$TESTDIR/binfile.bin" >> b
  $ hg ci -m anotherchange

don't sit forever trying to double-lock the source repo

  $ hg relink .
  relinking $TESTTMP/repo/.hg/store to $TESTTMP/repo/.hg/store (glob)
  there is nothing to relink


Test files are read in binary mode

  $ $PYTHON -c "file('.hg/store/data/dummy.i', 'wb').write('a\r\nb\n')"
  $ cd ..


clone and pull to break links

  $ hg clone --pull -r0 repo clone
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd clone
  $ hg pull -q
  $ echo b >> b
  $ hg ci -m changeb
  created new head
  $ $PYTHON -c "file('.hg/store/data/dummy.i', 'wb').write('a\nb\r\n')"


relink

  $ hg relink --debug | fix_path
  relinking $TESTTMP/repo/.hg/store to $TESTTMP/clone/.hg/store
  tip has 2 files, estimated total number of files: 3
  collecting: 00changelog.i 1/3 files (33.33%)
  collecting: 00manifest.i 2/3 files (66.67%)
  collecting: a.i 3/3 files (100.00%)
  collecting: b.i 4/3 files (133.33%)
  collecting: dummy.i 5/3 files (166.67%)
  collected 5 candidate storage files
  not linkable: 00changelog.i
  not linkable: 00manifest.i
  pruning: data/a.i 3/5 files (60.00%)
  not linkable: data/b.i
  pruning: data/dummy.i 5/5 files (100.00%)
  pruned down to 2 probably relinkable files
  relinking: data/a.i 1/2 files (50.00%)
  not linkable: data/dummy.i
  relinked 1 files (1.36 KB reclaimed)
  $ cd ..


check hardlinks

  $ python arelinked.py repo/.hg/store/data/a.i clone/.hg/store/data/a.i
  repo/.hg/store/data/a.i == clone/.hg/store/data/a.i
  $ python arelinked.py repo/.hg/store/data/b.i clone/.hg/store/data/b.i
  repo/.hg/store/data/b.i != clone/.hg/store/data/b.i