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
1 files updated, 0 files merged, 2 files removed, 0 files unresolved
rev offset length base linkrev nodeid p1 p2
0 0 3 0 0 362fef284ce2 000000000000 000000000000
1 3 5 1 1 125144f7e028 362fef284ce2 000000000000
2 8 7 2 2 4c982badb186 125144f7e028 000000000000
3 15 9 3 3 19b1fc555737 4c982badb186 000000000000
rev offset length base linkrev nodeid p1 p2
0 0 75 0 7 2565f3199a74 000000000000 000000000000
rev offset length base linkrev nodeid p1 p2
0 0 75 0 8 2565f3199a74 000000000000 000000000000
rev offset length base linkrev nodeid p1 p2
0 0 8 0 6 12ab3bcc5ea4 000000000000 000000000000
rev offset length base linkrev nodeid p1 p2
0 0 48 0 0 43eadb1d2d06 000000000000 000000000000
1 48 48 1 1 8b89697eba2c 43eadb1d2d06 000000000000
2 96 48 2 2 626a32663c2f 8b89697eba2c 000000000000
3 144 48 3 3 f54c32f13478 626a32663c2f 000000000000
4 192 58 3 6 de68e904d169 626a32663c2f 000000000000
5 250 68 3 7 09bb521d218d de68e904d169 000000000000
6 318 54 6 8 1fde233dfb0f f54c32f13478 000000000000
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 9 changesets, 7 total revisions
pushing to test-0
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
pushing to test-1
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
pushing to test-2
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 3 changesets, 3 total revisions
pushing to test-3
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 1 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 4 changesets, 4 total revisions
pushing to test-4
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
pushing to test-5
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 3 changesets, 3 total revisions
pushing to test-6
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 5 changes to 2 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 4 changesets, 5 total revisions
pushing to test-7
searching for changes
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 3 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 5 changesets, 6 total revisions
pushing to test-8
searching for changes
adding changesets
adding manifests
adding file changes
added 5 changesets with 5 changes to 2 files
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 5 changesets, 5 total revisions
pulling from ../test-7
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 2 changes to 3 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 9 changesets, 7 total revisions