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

if test x"$1" != x ; then
  cd $1
fi

if [ ! -d ".hg" ]; then
    echo "${1:-.} is not a mercurial repository" 1>&2
    echo "Aborting" 1>&2
    exit 1
fi
if [ ! -d ".git" ]; then
    mkdir -v ".git"
fi
if [ -e ".git/HEAD" ]; then
    if [ ! -e ".git/HEAD.hg-viz-save" ]; then
        mv -v ".git/HEAD" ".git/HEAD.hg-viz-save"
    else
        rm -vf ".git/HEAD"
    fi
fi
hg history | head -1 | awk -F: '{print $3}' > .git/HEAD
git-viz