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
===================================================================
#header#
<title>#repo|escape#: #file# diff</title>
</head>
<body>
<div class="buttons">
<a href="?cmd=changelog;rev=#rev#">changelog</a>
<a href="?cmd=tags">tags</a>
<a href="?cmd=changeset;node=#node#">changeset</a>
<a href="?cmd=file;file=#file#;filenode=#filenode#">file</a>
<a href="?cmd=filelog;file=#file#;filenode=#filenode#">revisions</a>
<a href="?cmd=annotate;file=#file#;filenode=#filenode#">annotate</a>
<a href="?cmd=filediff;file=#file#;node=#node#;style=raw">raw</a>
</div>
<h2>#file#</h2>
<table id="filediffEntry">
<tr>
<th class="revision">revision #rev#:</th>
<td class="revision"><a href="?cmd=changeset;node=#node#">#node|short#</a></td>
</tr>
#parent#
</table>
<div id="fileDiff">
#diff#
</div>
#footer#