view tests/test-convert-bzr-directories.t @ 32200:4d504e541d3d

rebase: use matcher to optimize manifestmerge

The old merge code would call manifestmerge and calculate the complete diff
between the source to the destination. In many cases, like rebase, the vast
majority of differences between the source and destination are irrelevant
because they are differences between the destination and the common ancestor
only, and therefore don't affect the merge. Since most actions are 'keep', all
the effort to compute them is wasted.

Instead, let's compute the difference between the source and the common ancestor
and only perform the diff of those files against the merge destination. When
using treemanifest, this lets us avoid loading almost the entire tree when
rebasing from a very old ancestor. This speeds up rebase of an old stack of 27
commits by 20x.

In mozilla-central, without treemanifest, when rebasing a commit from
default~100000 to default, this speeds up the manifestmerge step from 2.6s to
1.2s.  However, the additional diff adds an overhead to all manifestmerge calls,
especially for flat manifests. When rebasing a commit from default~1 to default
it appears to add 100ms in mozilla-central. While we could put this optimization
behind a flag, I think the fact that it makes merge O(number of changes being
applied) instead of O(number of changes between X and Y) justifies it.

#require bzr

  $ . "$TESTDIR/bzr-definitions"

empty directory

  $ mkdir test-empty
  $ cd test-empty
  $ bzr init -q source
  $ cd source
  $ echo content > a
  $ bzr add -q a
  $ bzr commit -q -m 'Initial add'
  $ mkdir empty
  $ bzr add -q empty
  $ bzr commit -q -m 'Empty directory added'
  $ echo content > empty/something
  $ bzr add -q empty/something
  $ bzr commit -q -m 'Added file into directory'
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  2 Initial add
  1 Empty directory added
  0 Added file into directory
  $ manifest source-hg 1
  % manifest of 1
  644   a
  $ manifest source-hg tip
  % manifest of tip
  644   a
  644   empty/something
  $ cd ..

directory renames

  $ mkdir test-dir-rename
  $ cd test-dir-rename
  $ bzr init -q source
  $ cd source
  $ mkdir tpyo
  $ echo content > tpyo/something
  $ bzr add -q tpyo
  $ bzr commit -q -m 'Added directory'
  $ bzr mv tpyo typo
  tpyo => typo
  $ bzr commit -q -m 'Oops, typo'
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  1 Added directory
  0 Oops, typo
  $ manifest source-hg 0
  % manifest of 0
  644   tpyo/something
  $ manifest source-hg tip
  % manifest of tip
  644   typo/something
  $ cd ..

nested directory renames

  $ mkdir test-nested-dir-rename
  $ cd test-nested-dir-rename
  $ bzr init -q source
  $ cd source
  $ mkdir -p firstlevel/secondlevel/thirdlevel
  $ echo content > firstlevel/secondlevel/file
  $ echo this_needs_to_be_there_too > firstlevel/secondlevel/thirdlevel/stuff
  $ bzr add -q firstlevel
  $ bzr commit -q -m 'Added nested directories'
  $ bzr mv firstlevel/secondlevel secondlevel
  firstlevel/secondlevel => secondlevel
  $ bzr commit -q -m 'Moved secondlevel one level up'
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  1 Added nested directories
  0 Moved secondlevel one level up
  $ manifest source-hg tip
  % manifest of tip
  644   secondlevel/file
  644   secondlevel/thirdlevel/stuff
  $ cd ..

directory remove

  $ mkdir test-dir-remove
  $ cd test-dir-remove
  $ bzr init -q source
  $ cd source
  $ mkdir src
  $ echo content > src/sourcecode
  $ bzr add -q src
  $ bzr commit -q -m 'Added directory'
  $ bzr rm -q src
  $ bzr commit -q -m 'Removed directory'
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  1 Added directory
  0 Removed directory
  $ manifest source-hg 0
  % manifest of 0
  644   src/sourcecode
  $ manifest source-hg tip
  % manifest of tip
  $ cd ..

directory replace

  $ mkdir test-dir-replace
  $ cd test-dir-replace
  $ bzr init -q source
  $ cd source
  $ mkdir first second
  $ echo content > first/file
  $ echo morecontent > first/dummy
  $ echo othercontent > second/something
  $ bzr add -q first second
  $ bzr commit -q -m 'Initial layout'
  $ bzr mv first/file second/file
  first/file => second/file
  $ bzr mv first third
  first => third
  $ bzr commit -q -m 'Some conflicting moves'
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  1 Initial layout
  0 Some conflicting moves
  $ manifest source-hg tip
  % manifest of tip
  644   second/file
  644   second/something
  644   third/dummy
  $ cd ..

divergent nested renames (issue3089)

  $ mkdir test-divergent-renames
  $ cd test-divergent-renames
  $ bzr init -q source
  $ cd source
  $ mkdir -p a/c
  $ echo a > a/fa
  $ echo c > a/c/fc
  $ bzr add -q a
  $ bzr commit -q -m 'Initial layout'
  $ bzr mv a b
  a => b
  $ mkdir a
  $ bzr add a
  add(ed|ing) a (re)
  $ bzr mv b/c a/c
  b/c => a/c
  $ bzr status
  added:
    a/
  renamed:
    a/? => b/? (re)
    a/c/? => a/c/? (re)
  $ bzr commit -q -m 'Divergent renames'
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  1 Initial layout
  0 Divergent renames
  $ hg -R source-hg st -C --change 1
  A b/fa
    a/fa
  R a/fa
  $ hg -R source-hg manifest -r 1
  a/c/fc
  b/fa
  $ cd ..