diff options
| author |   hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 03:10:21 -0500 |
|---|---|---|
| committer | hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 03:10:21 -0500 |
| commit | c0b7206652b2852bc574694e7ba07ba1c2acdc00 (patch) | |
| tree | 5cb95cb0e19e03610525903df46279df2c3b7eb1 /rubbos/app/apache2/manual/developer/hooks.html.en | |
| parent | b6d3d6e668b793220f2d3af1bc3e828553dc3fe6 (diff) | |
delete app
Change-Id: Id4c572809969ebe89e946e88063eaed262cff3f2
Signed-off-by: hongbotian <hongbo.tianhongbo@huawei.com>
Diffstat (limited to 'rubbos/app/apache2/manual/developer/hooks.html.en')
| -rw-r--r-- | rubbos/app/apache2/manual/developer/hooks.html.en | 239 |
1 files changed, 0 insertions, 239 deletions
diff --git a/rubbos/app/apache2/manual/developer/hooks.html.en b/rubbos/app/apache2/manual/developer/hooks.html.en deleted file mode 100644 index b89e9906..00000000 --- a/rubbos/app/apache2/manual/developer/hooks.html.en +++ /dev/null @@ -1,239 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!-- - XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - This file is generated from xml source: DO NOT EDIT - XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - --> -<title>Apache 2.0 Hook Functions - Apache HTTP Server</title> -<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> -<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> -<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /> -<link href="../images/favicon.ico" rel="shortcut icon" /></head> -<body id="manual-page"><div id="page-header"> -<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p> -<p class="apache">Apache HTTP Server Version 2.0</p> -<img alt="" src="../images/feather.gif" /></div> -<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div> -<div id="path"> -<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.0</a> > <a href="./">Developer Documentation</a></div><div id="page-content"><div id="preamble"><h1>Apache 2.0 Hook Functions</h1> -<div class="toplang"> -<p><span>Available Languages: </span><a href="../en/developer/hooks.html" title="English"> en </a></p> -</div> - - <div class="warning"><h3>Warning</h3> - <p>This document is still in development and may be partially out of - date.</p> - </div> - - <p>In general, a hook function is one that Apache will call at - some point during the processing of a request. Modules can - provide functions that are called, and specify when they get - called in comparison to other modules.</p> -</div> -<div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#create">Creating a hook function</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#hooking">Hooking the hook</a></li> -</ul></div> -<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="create" id="create">Creating a hook function</a></h2> - <p>In order to create a new hook, four things need to be - done:</p> - - <h3><a name="create-declare" id="create-declare">Declare the hook function</a></h3> - <p>Use the <code>AP_DECLARE_HOOK</code> macro, which needs to be given - the return type of the hook function, the name of the hook, and the - arguments. For example, if the hook returns an <code>int</code> and - takes a <code>request_rec *</code> and an <code>int</code> and is - called <code>do_something</code>, then declare it like this:</p> - <div class="example"><p><code> - AP_DECLARE_HOOK(int, do_something, (request_rec *r, int n)) - </code></p></div> - - <p>This should go in a header which modules will include if - they want to use the hook.</p> - - - <h3><a name="create-create" id="create-create">Create the hook structure</a></h3> - <p>Each source file that exports a hook has a private structure - which is used to record the module functions that use the hook. - This is declared as follows:</p> - - <div class="example"><p><code> - APR_HOOK_STRUCT(<br /> - <span class="indent"> - APR_HOOK_LINK(do_something)<br /> - ...<br /> - </span> - ) - </code></p></div> - - - <h3><a name="create-implement" id="create-implement">Implement the hook caller</a></h3> - <p>The source file that exports the hook has to implement a - function that will call the hook. There are currently three - possible ways to do this. In all cases, the calling function is - called <code>ap_run_<var>hookname</var>()</code>.</p> - - <h4>Void hooks</h4> - <p>If the return value of a hook is <code>void</code>, then all the - hooks are called, and the caller is implemented like this:</p> - - <div class="example"><p><code> - AP_IMPLEMENT_HOOK_VOID(do_something, (request_rec *r, int n), (r, n)) - </code></p></div> - - <p>The second and third arguments are the dummy argument - declaration and the dummy arguments as they will be used when - calling the hook. In other words, this macro expands to - something like this:</p> - - <div class="example"><p><code> - void ap_run_do_something(request_rec *r, int n)<br /> - {<br /> - <span class="indent"> - ...<br /> - do_something(r, n);<br /> - </span> - } - </code></p></div> - - - <h4>Hooks that return a value</h4> - <p>If the hook returns a value, then it can either be run until - the first hook that does something interesting, like so:</p> - - <div class="example"><p><code> - AP_IMPLEMENT_HOOK_RUN_FIRST(int, do_something, (request_rec *r, int n), (r, n), DECLINED) - </code></p></div> - - <p>The first hook that does <em>not</em> return <code>DECLINED</code> - stops the loop and its return value is returned from the hook - caller. Note that <code>DECLINED</code> is the tradition Apache - hook return meaning "I didn't do anything", but it can be - whatever suits you.</p> - - <p>Alternatively, all hooks can be run until an error occurs. - This boils down to permitting <em>two</em> return values, one of - which means "I did something, and it was OK" and the other - meaning "I did nothing". The first function that returns a - value other than one of those two stops the loop, and its - return is the return value. Declare these like so:</p> - - <div class="example"><p><code> - AP_IMPLEMENT_HOOK_RUN_ALL(int, do_something, (request_rec *r, int n), (r, n), OK, DECLINED) - </code></p></div> - - <p>Again, <code>OK</code> and <code>DECLINED</code> are the traditional - values. You can use what you want.</p> - - - - <h3><a name="create-call" id="create-call">Call the hook callers</a></h3> - <p>At appropriate moments in the code, call the hook caller, - like so:</p> - - <div class="example"><p><code> - int n, ret;<br /> - request_rec *r;<br /> - <br /> - ret=ap_run_do_something(r, n); - </code></p></div> - -</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="hooking" id="hooking">Hooking the hook</a></h2> - <p>A module that wants a hook to be called needs to do two - things.</p> - - <h3><a name="hooking-implement" id="hooking-implement">Implement the hook function</a></h3> - <p>Include the appropriate header, and define a static function - of the correct type:</p> - - <div class="example"><p><code> - static int my_something_doer(request_rec *r, int n)<br /> - {<br /> - <span class="indent"> - ...<br /> - return OK;<br /> - </span> - } - </code></p></div> - - - <h3><a name="hooking-add" id="hooking-add">Add a hook registering function</a></h3> - <p>During initialisation, Apache will call each modules hook - registering function, which is included in the module - structure:</p> - - <div class="example"><p><code> - static void my_register_hooks()<br /> - {<br /> - <span class="indent"> - ap_hook_do_something(my_something_doer, NULL, NULL, HOOK_MIDDLE);<br /> - </span> - }<br /> - <br /> - mode MODULE_VAR_EXPORT my_module =<br /> - {<br /> - <span class="indent"> - ...<br /> - my_register_hooks /* register hooks */<br /> - </span> - }; - </code></p></div> - - - <h3><a name="hooking-order" id="hooking-order">Controlling hook calling order</a></h3> - <p>In the example above, we didn't use the three arguments in - the hook registration function that control calling order. - There are two mechanisms for doing this. The first, rather - crude, method, allows us to specify roughly where the hook is - run relative to other modules. The final argument control this. - There are three possible values: <code>HOOK_FIRST</code>, - <code>HOOK_MIDDLE</code> and <code>HOOK_LAST</code>.</p> - - <p>All modules using any particular value may be run in any - order relative to each other, but, of course, all modules using - <code>HOOK_FIRST</code> will be run before <code>HOOK_MIDDLE</code> - which are before <code>HOOK_LAST</code>. Modules that don't care - when they are run should use <code>HOOK_MIDDLE</code>. <em>(I spaced - these out so people could do stuff like <code>HOOK_FIRST-2</code> - to get in slightly earlier, but is this wise? - Ben)</em></p> - - <p>Note that there are two more values, - <code>HOOK_REALLY_FIRST</code> and <code>HOOK_REALLY_LAST</code>. These - should only be used by the hook exporter.</p> - - <p>The other method allows finer control. When a module knows - that it must be run before (or after) some other modules, it - can specify them by name. The second (third) argument is a - NULL-terminated array of strings consisting of the names of - modules that must be run before (after) the current module. For - example, suppose we want "mod_xyz.c" and "mod_abc.c" to run - before we do, then we'd hook as follows:</p> - - <div class="example"><p><code> - static void register_hooks()<br /> - {<br /> - <span class="indent"> - static const char * const aszPre[] = { "mod_xyz.c", "mod_abc.c", NULL };<br /> - <br /> - ap_hook_do_something(my_something_doer, aszPre, NULL, HOOK_MIDDLE);<br /> - </span> - } - </code></p></div> - - <p>Note that the sort used to achieve this is stable, so - ordering set by <code>HOOK_<var>ORDER</var></code> is preserved, as far - as is possible.</p> - - <p class="cite"><cite>Ben Laurie</cite>, 15th August 1999</p> - -</div></div> -<div class="bottomlang"> -<p><span>Available Languages: </span><a href="../en/developer/hooks.html" title="English"> en </a></p> -</div><div id="footer"> -<p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p> -<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div> -</body></html>
\ No newline at end of file |