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)
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "bookmarks=" >> $HGRCPATH
hg init
echo % no bookmarks
hg bookmarks
echo % bookmark rev -1
hg bookmark X
echo % list bookmarks
hg bookmarks
echo % list bookmarks with color
hg --config extensions.color= bookmarks --color=always
echo a > a
hg add a
hg commit -m 0
echo % bookmark X moved to rev 0
hg bookmarks
echo % look up bookmark
hg log -r X
echo % second bookmark for rev 0
hg bookmark X2
echo % bookmark rev -1 again
hg bookmark -r null Y
echo % list bookmarks
hg bookmarks
echo b > b
hg add b
hg commit -m 1
echo % bookmarks X and X2 moved to rev 1, Y at rev -1
hg bookmarks
echo % bookmark rev 0 again
hg bookmark -r 0 Z
echo c > c
hg add c
hg commit -m 2
echo % bookmarks X and X2 moved to rev 2, Y at rev -1, Z at rev 0
hg bookmarks
echo % rename nonexistent bookmark
hg bookmark -m A B
echo % rename to existent bookmark
hg bookmark -m X Y
echo % force rename to existent bookmark
hg bookmark -f -m X Y
echo % list bookmarks
hg bookmark
echo % rename without new name
hg bookmark -m Y
echo % delete without name
hg bookmark -d
echo % delete nonexistent bookmark
hg bookmark -d A
echo % bookmark name with spaces should be stripped
hg bookmark ' x y '
echo % list bookmarks
hg bookmarks
echo % look up stripped bookmark name
hg log -r 'x y'
echo % reject bookmark name with newline
hg bookmark '
'
echo % bookmark with existing name
hg bookmark Z
echo % force bookmark with existing name
hg bookmark -f Z
echo % list bookmarks
hg bookmark
echo % revision but no bookmark name
hg bookmark -r .
true