wireprotov2: change how revisions are specified to changesetdata
Right now, we have a handful of arguments for specifying the revisions
whose data should be returned. Defining how all these arguments
interact when various combinations are present is difficult.
This commit establishes a new, generic mechanism for specifying
revisions. Instead of a hodgepodge of arguments defining things, we
have a list of dicts that specify revision selectors. The final set
of revisions is a union of all these selectors.
We implement support for specifying revisions based on:
* An explicit list of changeset revisions
* An explicit list of changeset revisions plus ancestry depth
* A DAG range between changeset roots and heads
If you squint hard enough, this problem has already been solved by
revsets. But I'm reluctant to expose revsets to the wire protocol
because that would require servers to implement a revset parser.
Plus there are security and performance implications: the set
of revision selectors needs to be narrowly and specifically tailored
for what is appropriate to be executing on a server. Perhaps there
would be a way for us to express the "parse tree" of a revset
query, for example. I'm not sure. We can explore this space another
time. For now, the new mechanism should bring sufficient flexibility
while remaining relatively simple.
The selector "types" are prefixed with "changeset" because I plan
to add manifest and file-flavored selectors as well. This will enable
us to e.g. select file revisions based on a range of changeset
revisions.
Differential Revision: https://phab.mercurial-scm.org/D4979
#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> 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> 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> 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> 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> 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> 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