tests/test-rename-dir-merge.out

findrenames: Optimise "addremove -s100" by matching files by their SHA1 hashes.

We speed up 'findrenames' for the usecase when a user specifies they
want a similarity of 100% by matching files by their exact SHA1 hash
value. This reduces the number of comparisons required to find exact
matches from O(n^2) to O(n).

While it would be nice if we could just use mercurial's pre-calculated
SHA1 hash for existing files, this hash includes the file's ancestor
information making it unsuitable for our purposes. Instead, we calculate
the hash of old content from scratch.

The following benchmarks were taken on the current head of crew:

addremove 100% similarity:
  rm -rf *; hg up -C; mv tests tests.new
  hg --time addremove -s100 --dry-run

  before:  real 176.350 secs (user 128.890+0.000 sys 47.430+0.000)
  after:   real   2.130 secs (user   1.890+0.000 sys  0.240+0.000)

addremove 75% similarity:
  rm -rf *; hg up -C; mv tests tests.new; \
      for i in tests.new/*; do echo x >> $i; done
  hg --time addremove -s75  --dry-run

  before: real 264.560 secs (user 215.130+0.000 sys 49.410+0.000)
  after:  real 218.710 secs (user 172.790+0.000 sys 45.870+0.000)

adding a/a
adding a/b
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
moving a/a to b/a
moving a/b to b/b
2 files updated, 0 files merged, 2 files removed, 0 files unresolved
created new head
  searching for copies back to rev 1
  unmatched files in local:
   a/c
   a/d
  unmatched files in other:
   b/a
   b/b
  all copies found (* = to merge, ! = divergent):
   b/a -> a/a 
   b/b -> a/b 
  checking for directory renames
  dir a/ -> b/
  file a/c -> b/c
  file a/d -> b/d
resolving manifests
 overwrite None partial False
 ancestor f9b20c0d4c51 local ce36d17b18fb+ remote 397f8b00a740
 a/d: remote renamed directory to b/d -> d
 a/c: remote renamed directory to b/c -> d
 a/b: other deleted -> r
 a/a: other deleted -> r
 b/a: remote created -> g
 b/b: remote created -> g
update: a/a 1/6 files (16.67%)
removing a/a
update: a/b 2/6 files (33.33%)
removing a/b
update: a/c 3/6 files (50.00%)
moving a/c to b/c
update: a/d 4/6 files (66.67%)
moving a/d to b/d
update: b/a 5/6 files (83.33%)
getting b/a
update: b/b 6/6 files (100.00%)
getting b/b
4 files updated, 0 files merged, 2 files removed, 0 files unresolved
(branch merge, don't forget to commit)
a/* b/a b/b b/c b/d
M b/a
M b/b
A b/c
  a/c
R a/a
R a/b
R a/c
? b/d
b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  searching for copies back to rev 1
  unmatched files in local:
   b/a
   b/b
   b/d
  unmatched files in other:
   a/c
  all copies found (* = to merge, ! = divergent):
   b/a -> a/a 
   b/b -> a/b 
  checking for directory renames
  dir a/ -> b/
  file a/c -> b/c
resolving manifests
 overwrite None partial False
 ancestor f9b20c0d4c51 local 397f8b00a740+ remote ce36d17b18fb
 None: local renamed directory to b/c -> d
update:None 1/1 files (100.00%)
getting a/c to b/c
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
a/* b/a b/b b/c b/d
A b/c
  a/c
? b/d
created new head
b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88