New lazy index code for revlogs. This tunes for large repositories. It does not read the whole index file in one big chunk, but tries to buffer reads in more reasonable chunks instead. Search speeds are improved in two ways. When trying to find a specific sha hash, it searches from the end of the file backward. More recent entries are more likely to be relevant, especially the tip. Also, this can load only the mapping of nodes to revlog index number. Loading the map uses less cpu (no struct.unpack) and much less memory than loading both the map and the index. This cuts down the time for hg tip on the 80,000 changeset kernel repo from 1.8s to 3.69s. Most commands the pull a single rev out of a big index get roughly the same benefit. Commands that read the whole index are not slower.

#!/bin/sh

cat <<'EOF' > merge
#!/bin/sh
echo merging for `basename $1`
EOF
chmod +x merge
HGMERGE=./merge; export HGMERGE

mkdir A1
cd A1
hg init
echo This is file foo1 > foo
echo This is file bar1 > bar
hg add foo bar
hg commit -m "commit text" -d "1000000 0"

cd ..
hg clone A1 B1

cd A1
rm bar
hg remove bar
hg commit -m "commit test" -d "1000000 0"

cd ../B1
echo This is file foo22 > foo
hg commit -m "commit test" -d "1000000 0"

cd ..
hg clone A1 A2
hg clone B1 B2

cd A1
hg pull ../B1
hg update -m
hg commit -m "commit test" -d "1000000 0"
echo bar should remain deleted.
hg manifest

cd ../B2
hg pull ../A2
hg update -m
hg commit -m "commit test" -d "1000000 0"
echo bar should remain deleted.
hg manifest