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

set -e
mkdir r1
cd r1
hg init
echo a > a
hg addremove
hg commit -m "1" -d "0 0"

hg clone . ../r2
cd ../r2
hg up
echo abc > a
hg diff > ../d
sed "s/\(\(---\|+++\) [a-zA-Z0-9_/.-]*\).*/\1/" < ../d

cd ../r1
echo b > b
echo a2 > a
hg addremove
hg commit -m "2" -d "0 0"

cd ../r2
hg -q pull ../r1
hg status
hg --debug up
hg --debug up -m
hg parents
hg -v history
hg diff > ../d
sed "s/\(\(---\|+++\) [a-zA-Z0-9_/.-]*\).*/\1/" < ../d