commit: improve the files field of changelog for merges
Currently, the files list of merge commits repeats all the deletions
(either actual deletions, or files that got renamed) that happened
between base and p2 of the merge. If p2 is the main branch, the list
can easily be much bigger than the change being merged.
This results in various problems worth improving:
- changelog is bigger than necessary
- `hg log directory` lists many unrelated merge commits, and `hg log
-v -r commit` frequently fills multiple screens worth of files
- it possibly slows down adjustlinkrev, by forcing it to read more
manifests, and that function can certainly be a bottleneck
- the server side of pulls can waste a lot of time simply opening the
filelogs for pointless files (the constant factors for opening even
a tiny filelog is apparently pretty bad)
So stop listing such files as described in the code. Impacted merge
commits and their descendants get a different hash than they would
have without this. This doesn't seem problematic, except for
convert. The previous commit helped with that in the hg->hg case (but
if you do svn->hg twice from scratch, hashes can still change).
The rest of the description is numbers. I don't have much to report,
because recreating the files list of existing repositories is not
easy:
- debugupgradeformat and bundle/unbundle don't recreate the list
- export/import tends to choke quickly applying patches or on
description that contain diffs,
- merge commits from the convert extension don't have the right files
list for reasons orthogonal to the current commit
- replaying the merge with hg update/hg merge/hg revert --all/hg
commit can end up failing in hg revert
- I wasn't sure that using debugsetparents + debugrebuilddirstate
would really build the right thing
I measured commit time before and after this change, in a case with no
files filtered out, several files filtered out (no difference) and 5k
files filtered out (+1% time).
Recreating the 100 more recent merges in a private repo, the
concatenated uncompressed files lists goes from 1.12MB to
0.52MB. Excluding 3 merges that are not representative, then the size
goes from 570k to 15k.
I converted part of mozilla-central, and observed file list shrinking
quite a bit too, starting at the very first merge,
733641d9feaf, going
from 550 files to 10 files (although they have relatively few merges,
so they probably wouldn't care).
Differential Revision: https://phab.mercurial-scm.org/D6613
#require no-chg
$ send() {
> hg --verbose debugwireproto --peer raw http://$LOCALIP:$HGPORT/
> }
$ hg init server
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid
$ cat hg.pid > $DAEMON_PIDS
Request to /api fails unless web.apiserver is enabled
$ get-with-headers.py $LOCALIP:$HGPORT api
400 no such method: api
<!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>$TESTTMP/server: error</title>
</head>
<body>
<div class="container">
<div class="menu">
<div class="logo">
<a href="https://mercurial-scm.org/">
<img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial" /></a>
</div>
<ul>
<li><a href="/shortlog">log</a></li>
<li><a href="/graph">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="/help">help</a></li>
</ul>
</div>
<div class="main">
<h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
<h3>error</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">
<p>
An error occurred while processing your request:
</p>
<p>
no such method: api
</p>
</div>
</div>
</div>
</body>
</html>
[1]
$ get-with-headers.py $LOCALIP:$HGPORT api/
400 no such method: api
<!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>$TESTTMP/server: error</title>
</head>
<body>
<div class="container">
<div class="menu">
<div class="logo">
<a href="https://mercurial-scm.org/">
<img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial" /></a>
</div>
<ul>
<li><a href="/shortlog">log</a></li>
<li><a href="/graph">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="/help">help</a></li>
</ul>
</div>
<div class="main">
<h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
<h3>error</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">
<p>
An error occurred while processing your request:
</p>
<p>
no such method: api
</p>
</div>
</div>
</div>
</body>
</html>
[1]
Restart server with support for API server
$ killdaemons.py
$ cat > server/.hg/hgrc << EOF
> [experimental]
> web.apiserver = true
> EOF
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid
$ cat hg.pid > $DAEMON_PIDS
/api lists available APIs (empty since none are available by default)
$ send << EOF
> httprequest GET api
> user-agent: test
> EOF
using raw connection to peer
s> setsockopt(6, 1, 1) -> None (?)
s> GET /api HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: text/plain\r\n
s> Content-Length: 100\r\n
s> \r\n
s> APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
s> \n
s> (no available APIs)\n
$ send << EOF
> httprequest GET api/
> user-agent: test
> EOF
using raw connection to peer
s> setsockopt(6, 1, 1) -> None (?)
s> GET /api/ HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: text/plain\r\n
s> Content-Length: 100\r\n
s> \r\n
s> APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
s> \n
s> (no available APIs)\n
Accessing an unknown API yields a 404
$ send << EOF
> httprequest GET api/unknown
> user-agent: test
> EOF
using raw connection to peer
s> setsockopt(6, 1, 1) -> None (?)
s> GET /api/unknown HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 404 Not Found\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: text/plain\r\n
s> Content-Length: 33\r\n
s> \r\n
s> Unknown API: unknown\n
s> Known APIs:
Accessing a known but not enabled API yields a different error
$ send << EOF
> httprequest GET api/exp-http-v2-0003
> user-agent: test
> EOF
using raw connection to peer
s> setsockopt(6, 1, 1) -> None (?)
s> GET /api/exp-http-v2-0003 HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 404 Not Found\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: text/plain\r\n
s> Content-Length: 33\r\n
s> \r\n
s> API exp-http-v2-0003 not enabled\n
Restart server with support for HTTP v2 API
$ killdaemons.py
$ cat > server/.hg/hgrc << EOF
> [experimental]
> web.apiserver = true
> web.api.http-v2 = true
> EOF
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid
$ cat hg.pid > $DAEMON_PIDS
/api lists the HTTP v2 protocol as available
$ send << EOF
> httprequest GET api
> user-agent: test
> EOF
using raw connection to peer
s> setsockopt(6, 1, 1) -> None (?)
s> GET /api HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: text/plain\r\n
s> Content-Length: 96\r\n
s> \r\n
s> APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
s> \n
s> exp-http-v2-0003
$ send << EOF
> httprequest GET api/
> user-agent: test
> EOF
using raw connection to peer
s> setsockopt(6, 1, 1) -> None (?)
s> GET /api/ HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: text/plain\r\n
s> Content-Length: 96\r\n
s> \r\n
s> APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
s> \n
s> exp-http-v2-0003