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

mkdir t
cd t
hg init
hg id
echo a > a
hg add a
hg commit -m "test" -d "0 0"
hg co
hg identify
T=`hg -q tip | cut -d : -f 2`
echo "$T first" > .hgtags
cat .hgtags
hg add .hgtags
hg commit -m "add tags" -d "0 0"
hg tags
hg identify
echo bb > a
hg status
hg identify
hg co first
hg id
hg -v id
hg status
echo 1 > b
hg add b
hg commit -m "branch" -d "0 0"
hg id
hg co -m 1
hg id
hg status