view tests/test-encode @ 5339:058e93c3d07d

I have spotted the biggest bottleneck in "bdiff.c". Actually it was
pretty easy to find after I recompiled the python interpreter and
mercurial for profiling.

In "bdiff.c" function "equatelines" allocates the minimum hash table
size, which can lead to tons of collisions. I introduced an
"overcommit" factor of 16, this is, I allocate 16 times more memory
than the minimum value. Overcommiting 128 times does not improve the
performance over the 16-times case.

#!/bin/sh

hg init

cat > .hg/hgrc <<EOF
[encode]
*.gz = gunzip

[decode]
*.gz = gzip

EOF

echo "this is a test" | gzip > a.gz
hg add a.gz
hg ci -m "test" -d "1000000 0"
echo %% no changes
hg status
touch a.gz

echo %% no changes
hg status

echo %% uncompressed contents in repo
hg debugdata .hg/store/data/a.gz.d 0

echo %% uncompress our working dir copy
gunzip < a.gz

rm a.gz
hg co

echo %% uncompress our new working dir copy
gunzip < a.gz