revisionbranchcache: fall back to slow path if starting readonly (issue4531)
Transitioning to Mercurial versions with revision branch cache could be slow as
long as all operations were readonly (revset queries) and the cache would be
populated but not written back.
Instead, fall back to using the consistently slow path when readonly and the
cache doesn't exist yet. That avoids the overhead of populating the cache
without writing it back.
If not readonly, it will still populate all missing entries initially. That
avoids repeated writing of the cache file with small updates, and it also makes
sure a fully populated cache available for the readonly operations.
#require serve
setting up repo
$ hg init test
$ cd test
$ echo a > a
$ hg ci -Ama
adding a
$ hg rm a
$ hg ci -mdel
set up hgweb
$ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
$ cat hg.pid >> $DAEMON_PIDS
revision
$ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'rev/tip'
200 Script output follows
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
<head>
<link rel="icon" href="/static/hgicon.png" type="image/png" />
<meta name="robots" content="index, nofollow" />
<link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
<script type="text/javascript" src="/static/mercurial.js"></script>
<title>test: c78f6c5cbea9</title>
</head>
<body>
<div class="container">
<div class="menu">
<div class="logo">
<a href="http://mercurial.selenic.com/">
<img src="/static/hglogo.png" alt="mercurial" /></a>
</div>
<ul>
<li><a href="/shortlog/c78f6c5cbea9">log</a></li>
<li><a href="/graph/c78f6c5cbea9">graph</a></li>
<li><a href="/tags">tags</a></li>
<li><a href="/bookmarks">bookmarks</a></li>
<li><a href="/branches">branches</a></li>
</ul>
<ul>
<li class="active">changeset</li>
<li><a href="/raw-rev/c78f6c5cbea9">raw</a></li>
<li><a href="/file/c78f6c5cbea9">browse</a></li>
</ul>
<ul>
</ul>
<ul>
<li><a href="/help">help</a></li>
</ul>
</div>
<div class="main">
<h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
<h3>changeset 1:c78f6c5cbea9 <span class="tag">tip</span> </h3>
<form class="search" action="/log">
<p><input name="rev" id="search1" type="text" size="30" /></p>
<div id="hint">Find changesets by keywords (author, files, the commit message), revision
number or hash, or <a href="/help/revsets">revset expression</a>.</div>
</form>
<div class="description">del</div>
<table id="changesetEntry">
<tr>
<th class="author">author</th>
<td class="author">test</td>
</tr>
<tr>
<th class="date">date</th>
<td class="date age">Thu, 01 Jan 1970 00:00:00 +0000</td></tr>
<tr>
<th class="author">parents</th>
<td class="author"><a href="/rev/cb9a9f314b8b">cb9a9f314b8b</a> </td>
</tr>
<tr>
<th class="author">children</th>
<td class="author"></td>
</tr>
<tr>
<th class="files">files</th>
<td class="files">a </td>
</tr>
<tr>
<th class="diffstat">diffstat</th>
<td class="diffstat">
1 files changed, 0 insertions(+), 1 deletions(-)
<a id="diffstatexpand" href="javascript:toggleDiffstat()">[<tt>+</tt>]</a>
<div id="diffstatdetails" style="display:none;">
<a href="javascript:toggleDiffstat()">[<tt>-</tt>]</a>
<p></p>
<table class="stripes2"> <tr>
<td class="diffstat-file"><a href="#l1.1">a</a></td>
<td class="diffstat-total" align="right">1</td>
<td class="diffstat-graph">
<span class="diffstat-add" style="width:0.0%;"> </span>
<span class="diffstat-remove" style="width:100.0%;"> </span>
</td>
</tr>
</table>
</div>
</td>
</tr>
</table>
<div class="overflow">
<div class="sourcefirst linewraptoggle">line wrap: <a class="linewraplink" href="javascript:toggleLinewrap()">on</a></div>
<div class="sourcefirst"> line diff</div>
<div class="stripes2 diffblocks">
<div class="bottomline inc-lineno"><pre class="sourcelines wrap">
<span id="l1.1" class="minusline">--- a/a Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.1"></a>
<span id="l1.2" class="plusline">+++ /dev/null Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.2"></a>
<span id="l1.3" class="atline">@@ -1,1 +0,0 @@</span><a href="#l1.3"></a>
<span id="l1.4" class="minusline">-a</span><a href="#l1.4"></a></pre></div>
</div>
</div>
</div>
</div>
<script type="text/javascript">process_dates()</script>
</body>
</html>
diff removed file
$ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'diff/tip/a'
200 Script output follows
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
<head>
<link rel="icon" href="/static/hgicon.png" type="image/png" />
<meta name="robots" content="index, nofollow" />
<link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
<script type="text/javascript" src="/static/mercurial.js"></script>
<title>test: a diff</title>
</head>
<body>
<div class="container">
<div class="menu">
<div class="logo">
<a href="http://mercurial.selenic.com/">
<img src="/static/hglogo.png" alt="mercurial" /></a>
</div>
<ul>
<li><a href="/shortlog/c78f6c5cbea9">log</a></li>
<li><a href="/graph/c78f6c5cbea9">graph</a></li>
<li><a href="/tags">tags</a></li>
<li><a href="/bookmarks">bookmarks</a></li>
<li><a href="/branches">branches</a></li>
</ul>
<ul>
<li><a href="/rev/c78f6c5cbea9">changeset</a></li>
<li><a href="/file/c78f6c5cbea9">browse</a></li>
</ul>
<ul>
<li><a href="/file/c78f6c5cbea9/a">file</a></li>
<li><a href="/file/tip/a">latest</a></li>
<li class="active">diff</li>
<li><a href="/comparison/c78f6c5cbea9/a">comparison</a></li>
<li><a href="/annotate/c78f6c5cbea9/a">annotate</a></li>
<li><a href="/log/c78f6c5cbea9/a">file log</a></li>
<li><a href="/raw-file/c78f6c5cbea9/a">raw</a></li>
</ul>
<ul>
<li><a href="/help">help</a></li>
</ul>
</div>
<div class="main">
<h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
<h3>diff a @ 1:c78f6c5cbea9</h3>
<form class="search" action="/log">
<p></p>
<p><input name="rev" id="search1" type="text" size="30" /></p>
<div id="hint">Find changesets by keywords (author, files, the commit message), revision
number or hash, or <a href="/help/revsets">revset expression</a>.</div>
</form>
<div class="description">del</div>
<table id="changesetEntry">
<tr>
<th>author</th>
<td>test</td>
</tr>
<tr>
<th>date</th>
<td class="date age">Thu, 01 Jan 1970 00:00:00 +0000</td>
</tr>
<tr>
<th>parents</th>
<td><a href="/file/cb9a9f314b8b/a">cb9a9f314b8b</a> </td>
</tr>
<tr>
<th>children</th>
<td></td>
</tr>
</table>
<div class="overflow">
<div class="sourcefirst linewraptoggle">line wrap: <a class="linewraplink" href="javascript:toggleLinewrap()">on</a></div>
<div class="sourcefirst"> line diff</div>
<div class="stripes2 diffblocks">
<div class="bottomline inc-lineno"><pre class="sourcelines wrap">
<span id="l1.1" class="minusline">--- a/a Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.1"></a>
<span id="l1.2" class="plusline">+++ /dev/null Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.2"></a>
<span id="l1.3" class="atline">@@ -1,1 +0,0 @@</span><a href="#l1.3"></a>
<span id="l1.4" class="minusline">-a</span><a href="#l1.4"></a></pre></div>
</div>
</div>
</div>
</div>
<script type="text/javascript">process_dates()</script>
</body>
</html>
$ cd ..