tests/test-convert-clonebranches

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 "convert = " >> $HGRCPATH
echo "[convert]" >> $HGRCPATH
echo "hg.tagsbranch=0" >> $HGRCPATH

hg init source
cd source
echo a > a
hg ci -qAm adda
# Add a merge with one parent in the same branch
echo a >> a
hg ci -qAm changea
hg up -qC 0
hg branch branch0
echo b > b
hg ci -qAm addb
hg up -qC
hg merge default
hg ci -qm mergeab
hg tag -ql mergeab
cd ..

# Miss perl... sometimes
cat > filter.py <<EOF
import sys, re

r = re.compile(r'^(?:\d+|pulling from)')
sys.stdout.writelines([l for l in sys.stdin if r.search(l)])
EOF

echo % convert
hg convert -v --config convert.hg.clonebranches=1 source dest |
    python filter.py

# Add a merge with both parents and child in different branches
cd source
hg branch branch1
echo a > file1
hg ci -qAm c1
hg up -qC mergeab
hg branch branch2
echo a > file2
hg ci -qAm c2
hg merge branch1
hg branch branch3
hg ci -qAm c3
cd ..

echo % incremental conversion
hg convert -v --config convert.hg.clonebranches=1 source dest |
    python filter.py