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 a
cd a
hg init
echo foo > t1
hg add t1
hg commit -m "1" -d "0 0"

cd ..
hg clone a b

cd a
echo foo > t2
hg add t2
hg commit -m "2" -d "0 0"

cd ../b
echo foo > t3
hg add t3
hg commit -m "3" -d "0 0"

hg push ../a
hg pull ../a
hg push ../a
hg up -m
hg commit -m "4" -d "0 0"
hg push ../a