dirstate walking optimizations The repo walking code introduces a number of calls to dirstate.map.copy(), significantly slowing down the walk on large trees. When a list of files is passed to the walking code, we should only look at map entries relevant to the file list passed in. dirstate.filterfiles() is added to return a subset of the dirstate map. The subset includes in files passed in, and if one of the files requested is actually a directory, it includes any files inside that directory tree. This brings the time for hg diff Makefile down from 1.7s to .3s on a linux kernel repo. Also, the diff command was unconditionally calling makewalk, leading to an extra pass through repo.changes. This patch avoids the call to makewalk when commands.diff isn't given a list of patterns, cutting the time for hg diff (with no args) in half. Index: mine/mercurial/hg.py ===================================================================

#!/bin/sh -e

umask 027
mkdir test1
cd test1

hg init
touch a b
hg add a b
hg ci -m "added a b" -d "0 0"

cd ..
mkdir test2
cd test2

hg init
hg pull ../test1
hg co
chmod +x a
hg ci -m "chmod +x a" -d "0 0"

cd ../test1
echo 123 >>a
hg ci -m "a updated" -d "0 0"

hg pull ../test2
hg heads
hg history

hg -v co -m

ls -l ../test[12]/a > foo
cut -b 0-10 < foo