branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
#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
$ 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="https://mercurial-scm.org/">
<img src="/static/hglogo.png" alt="mercurial" /></a>
</div>
<ul>
<li><a href="/shortlog/tip">log</a></li>
<li><a href="/graph/tip">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/tip">raw</a></li>
<li><a href="/file/tip">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:<a href="/rev/c78f6c5cbea9">c78f6c5cbea9</a>
<span class="phase">draft</span> <span class="branchhead">default</span> <span class="tag">tip</span>
</h3>
<form class="search" action="/log">
<p><input name="rev" id="search1" type="text" size="30" value="" /></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" class="diffstattoggle" href="#">[<tt>+</tt>]</a>
<div id="diffstatdetails" style="display:none;">
<a class="diffstattoggle" href="#">[<tt>-</tt>]</a>
<table class="diffstat-table 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="#">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>
</body>
</html>
diff removed file
$ 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="https://mercurial-scm.org/">
<img src="/static/hglogo.png" alt="mercurial" /></a>
</div>
<ul>
<li><a href="/shortlog/tip">log</a></li>
<li><a href="/graph/tip">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/tip">changeset</a></li>
<li><a href="/file/tip">browse</a></li>
</ul>
<ul>
<li><a href="/file/tip/a">file</a></li>
<li><a href="/file/tip/a">latest</a></li>
<li class="active">diff</li>
<li><a href="/comparison/tip/a">comparison</a></li>
<li><a href="/annotate/tip/a">annotate</a></li>
<li><a href="/log/tip/a">file log</a></li>
<li><a href="/raw-file/tip/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:<a href="/rev/c78f6c5cbea9">c78f6c5cbea9</a>
<span class="phase">draft</span> <span class="branchhead">default</span> <span class="tag">tip</span>
</h3>
<form class="search" action="/log">
<p><input name="rev" id="search1" type="text" size="30" value="" /></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="#">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>
</body>
</html>
$ cd ..