view tests/test-diff-copy-depth.t @ 14087:f3d585c9b042

graphmod: restore generator nature of dagwalker

9966c95b8c4f introduced the ability to walk the DAG
given arbitrary revisions, but changed the behaviour of
it to return a list of all nodes (and create a changectx
for each one) rather than doing it lazily.

This has a pretty significant impact on performance for large
repositories (tested on CPython repo, with output disabled):

  $ time hg glog

  real	0m2.642s
  user	0m2.560s
  sys	0m0.080s

Before 9966c95b8c4f:

  $ time hg glog

  real	0m0.143s
  user	0m0.112s
  sys	0m0.032s

And after this fix:

  $ time hg glog

  real	0m0.213s
  user	0m0.184s
  sys	0m0.028s

  $ for i in aaa zzz; do
  >     hg init t
  >     cd t
  > 
  >     echo
  >     echo "-- With $i"
  > 
  >     touch file
  >     hg add file
  >     hg ci -m "Add"
  > 
  >     hg cp file $i
  >     hg ci -m "a -> $i"
  > 
  >     hg cp $i other-file
  >     echo "different" >> $i
  >     hg ci -m "$i -> other-file"
  > 
  >     hg cp other-file somename
  > 
  >     echo "Status":
  >     hg st -C
  >     echo
  >     echo "Diff:"
  >     hg diff -g
  > 
  >     cd ..
  >     rm -rf t
  > done
  
  -- With aaa
  Status:
  A somename
    other-file
  
  Diff:
  diff --git a/other-file b/somename
  copy from other-file
  copy to somename
  
  -- With zzz
  Status:
  A somename
    other-file
  
  Diff:
  diff --git a/other-file b/somename
  copy from other-file
  copy to somename