outgoing: rework the handling of the `missingroots` case to be faster
The previous implementation was slow, to the point it was taking a significant
amount of `hg bundle --type none-streamv2` call. We rework the code to compute
the same value much faster, making the operation disappear from the `hg bundle
--type none-streamv2` profile. Someone would remark that producing a streamclone
does not requires an `outgoing` object. However that is a matter for another
day. There is other user of `missingroots` (non stream `hg bundle` call for
example), and they will also benefit from this rework.
We implement an old TODO in the process, directly computing the missing and
common attribute as we have most element at hand already.
### benchmark.name = hg.command.bundle
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.revs = all
# benchmark.variants.type = none-streamv2
## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog
before: 7.750458
after: 6.665565 (-14.00%, -1.08)
## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog
before: 0.700229
after: 0.496050 (-29.16%, -0.20)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 346.508952
after: 316.749699 (-8.59%, -29.76)
## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog
before: 3.401700
after: 2.915810 (-14.28%, -0.49)
## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog
before: 1.870798
after: 1.461583 (-21.87%, -0.41)
note: this whole `missingroots` of outgoing has a limited number of callers and
could likely be replace by something simpler (like taking an explicit
"missing_revs" set for example). However this is a wider change and we focus on
a small impact, quick rework that does not change the API for now.
#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 ..