tests/test-merge-commit.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)

1 files updated, 0 files merged, 0 files removed, 0 files unresolved
created new head
merging bar and foo to bar
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
% contents of bar should be line0 line1 line2
line0
line1
line2
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0      77      0       2 d35118874825 000000000000 000000000000
     1        77      76      0       3 5345f5ab8abd 000000000000 d35118874825
bar renamed from foo:9e25c27b87571a1edee5ae4dddee5687746cc8e2
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0       7      0       0 690b295714ae 000000000000 000000000000
     1         7      13      1       1 9e25c27b8757 690b295714ae 000000000000
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
created new head
4:2263c1be0967 2:0f2ff26688b9 
3:0555950ead28 2:0f2ff26688b9 1:5cd961e4045d 
2:0f2ff26688b9 0:2665aaee66e9 
1:5cd961e4045d 
0:2665aaee66e9 
% this should use bar@rev2 as the ancestor
  searching for copies back to rev 1
resolving manifests
 overwrite None partial False
 ancestor 0f2ff26688b9 local 2263c1be0967+ remote 0555950ead28
 bar: versions differ -> m
preserving bar for resolve of bar
update: bar 1/1 files (100.00%)
picked tool 'internal:merge' for bar (binary False symlink False)
merging bar
my bar@2263c1be0967+ other bar@0555950ead28 ancestor bar@0f2ff26688b9
 premerge successful
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
% contents of bar should be line1 line2
line1
line2
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0      77      0       2 d35118874825 000000000000 000000000000
     1        77      76      0       3 5345f5ab8abd 000000000000 d35118874825
     2       153       7      2       4 ff4b45017382 d35118874825 000000000000
     3       160      13      3       5 3701b4893544 ff4b45017382 5345f5ab8abd


requesting all changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 2 files (+1 heads)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
merging foo and bar to bar
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
% contents of bar should be line0 line1 line2
line0
line1
line2
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0      77      0       2 d35118874825 000000000000 000000000000
     1        77      76      0       3 5345f5ab8abd 000000000000 d35118874825
bar renamed from foo:9e25c27b87571a1edee5ae4dddee5687746cc8e2
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0       7      0       0 690b295714ae 000000000000 000000000000
     1         7      13      1       1 9e25c27b8757 690b295714ae 000000000000
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
created new head
4:2263c1be0967 2:0f2ff26688b9 
3:3ffa6b9e35f0 1:5cd961e4045d 2:0f2ff26688b9 
2:0f2ff26688b9 0:2665aaee66e9 
1:5cd961e4045d 
0:2665aaee66e9 
% this should use bar@rev2 as the ancestor
  searching for copies back to rev 1
resolving manifests
 overwrite None partial False
 ancestor 0f2ff26688b9 local 2263c1be0967+ remote 3ffa6b9e35f0
 bar: versions differ -> m
preserving bar for resolve of bar
update: bar 1/1 files (100.00%)
picked tool 'internal:merge' for bar (binary False symlink False)
merging bar
my bar@2263c1be0967+ other bar@3ffa6b9e35f0 ancestor bar@0f2ff26688b9
 premerge successful
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
% contents of bar should be line1 line2
line1
line2
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0      77      0       2 d35118874825 000000000000 000000000000
     1        77      76      0       3 5345f5ab8abd 000000000000 d35118874825
     2       153       7      2       4 ff4b45017382 d35118874825 000000000000
     3       160      13      3       5 3701b4893544 ff4b45017382 5345f5ab8abd