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
# This test makes sure that we don't mark a file as merged with its ancestor
# when we do a merge.
cat <<EOF > merge
import sys, os
print "merging for", os.path.basename(sys.argv[1])
EOF
HGMERGE="python ../merge"; export HGMERGE
echo creating base
hg init a
cd a
echo 1 > foo
echo 1 > bar
echo 1 > baz
echo 1 > quux
hg add foo bar baz quux
hg commit -m "base" -d "1000000 0"
cd ..
hg clone a b
echo creating branch a
cd a
echo 2a > foo
echo 2a > bar
hg commit -m "branch a" -d "1000000 0"
echo creating branch b
cd ..
cd b
echo 2b > foo
echo 2b > baz
hg commit -m "branch b" -d "1000000 0"
echo "we shouldn't have anything but n state here"
hg debugstate --nodates | grep -v "^n"
echo merging
hg pull ../a
hg merge -v
echo 2m > foo
echo 2b > baz
echo new > quux
echo "we shouldn't have anything but foo in merge state here"
hg debugstate --nodates | grep "^m"
hg ci -m "merge" -d "1000000 0"
echo "main: we should have a merge here"
hg debugindex .hg/store/00changelog.i
echo "log should show foo and quux changed"
hg log -v -r tip
echo "foo: we should have a merge here"
hg debugindex .hg/store/data/foo.i
echo "bar: we shouldn't have a merge here"
hg debugindex .hg/store/data/bar.i
echo "baz: we shouldn't have a merge here"
hg debugindex .hg/store/data/baz.i
echo "quux: we shouldn't have a merge here"
hg debugindex .hg/store/data/quux.i
echo "manifest entries should match tips of all files"
hg manifest --debug
echo "everything should be clean now"
hg status
hg verify