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
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#header#
<title>#repo|escape#: manifest #manifest|short#</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>
</div>
<h2>manifest #manifest|short#: #path#</h2>
<table cellpadding="0" cellspacing="0">
<tr class="parity1">
<td><tt>drwxr-xr-x</tt>
<td><a href="?cmd=manifest;manifest=#manifest#;path=#up#">[up]</a>
#entries#
</table>
#footer#