view tests/test-convert-bzr-114.t @ 30289:1f92056c4066

revlog: optimize _chunkraw when startrev==endrev

In many cases, _chunkraw() is called with startrev==endrev. When
this is true, we can avoid an extra index lookup and some other
minor operations.

On the mozilla-unified repo, `hg perfrevlogchunks -c` says this
has the following impact:

! read w/ reused fd
! wall 0.371846 comb 0.370000 user 0.350000 sys 0.020000 (best of 27)
! wall 0.337930 comb 0.330000 user 0.300000 sys 0.030000 (best of 30)

! read batch w/ reused fd
! wall 0.014952 comb 0.020000 user 0.000000 sys 0.020000 (best of 197)
! wall 0.014866 comb 0.010000 user 0.000000 sys 0.010000 (best of 196)

So, we've gone from ~25x slower than batch to ~22.5x slower.

At this point, there's probably not much else we can do except
implement an optimized function in the index itself, including in C.

#require bzr bzr114

  $ . "$TESTDIR/bzr-definitions"

The file/directory replacement can only be reproduced on
bzr >= 1.4. Merge it back in test-convert-bzr-directories once
this version becomes mainstream.
replace file with dir

  $ mkdir test-replace-file-with-dir
  $ cd test-replace-file-with-dir
  $ bzr init -q source
  $ cd source
  $ echo d > d
  $ bzr add -q d
  $ bzr commit -q -m 'add d file'
  $ rm d
  $ mkdir d
  $ bzr add -q d
  $ bzr commit -q -m 'replace with d dir'
  $ echo a > d/a
  $ bzr add -q d/a
  $ bzr commit -q -m 'add d/a'
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  2 add d file
  1 replace with d dir
  0 add d/a
  $ manifest source-hg tip
  % manifest of tip
  644   d/a
  $ cd source-hg
  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd ../..