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			554 lines
		
	
	
		
			26 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
<?xml version="1.0" encoding="ISO-8859-1"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
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        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
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              This file is generated from xml source: DO NOT EDIT
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        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
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      -->
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<title>API Changes in Apache HTTP Server 2.4 since 2.2 - Apache HTTP Server</title>
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<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
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<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
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<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
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<link href="../images/favicon.ico" rel="shortcut icon" /></head>
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<body id="manual-page"><div id="page-header">
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<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>
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<p class="apache">Apache HTTP Server Version 2.5</p>
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<img alt="" src="../images/feather.gif" /></div>
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<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
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<div id="path">
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<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 2.5</a></div><div id="page-content"><div id="preamble"><h1>API Changes in Apache HTTP Server 2.4 since 2.2</h1>
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<div class="toplang">
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<p><span>Available Languages: </span><a href="../en/developer/new_api_2_4.html" title="English"> en </a></p>
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</div>
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  <p>This document describes changes to the Apache HTTPD API from
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     version 2.2 to 2.4, that may be of interest to module/application
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     developers and core hacks.  As of the first GA release of the
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     2.4 branch API compatibility is preserved for the life of the
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     2.4 branch.  (The 
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     <a href="http://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x/VERSIONING">VERSIONING</a>
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     description for the 2.4 release provides more information about API
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     compatibility.)</p>
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  <p>API changes fall into two categories: APIs that are altogether new,
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     and existing APIs that are expanded or changed.  The latter are
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     further divided into those where all changes are backwards-compatible
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     (so existing modules can ignore them), and those that might
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     require attention by maintainers.  As with the transition from
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     HTTPD 2.0 to 2.2, existing modules and applications will require
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     recompiling and may call for some attention, but most should not
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     require any substantial updating (although some may be able to
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     take advantage of API changes to offer significant improvements).</p>
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  <p>For the purpose of this document, the API is split according
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     to the public header files.  These headers are themselves the
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     reference documentation, and can be used to generate a browsable
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     HTML reference with <code>make docs</code>.</p>
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</div>
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<div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#api_changes">Changed APIs</a></li>
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<li><img alt="" src="../images/down.gif" /> <a href="#upgrading">Specific information on upgrading modules from 2.2</a></li>
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</ul></div>
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<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
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<div class="section">
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<h2><a name="api_changes" id="api_changes">Changed APIs</a></h2>
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  <h3><a name="ap_expr" id="ap_expr">ap_expr (NEW!)</a></h3>
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    <p>Introduces a new API to parse and evaluate boolean and algebraic
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       expressions, including provision for a standard syntax and
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       customised variants.</p>
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  <h3><a name="ap_listen" id="ap_listen">ap_listen (changed; backwards-compatible)</a></h3>
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    <p>Introduces a new API to enable httpd child processes to serve
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       different purposes.</p>
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  <h3><a name="ap_mpm" id="ap_mpm">ap_mpm (changed)</a></h3>
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  <p><code>ap_mpm_run</code> is replaced by a new <code>mpm</code> hook.
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  Also <code>ap_graceful_stop_signalled</code> is lost, and
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  <code>ap_mpm_register_timed_callback</code> is new.</p>
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  <h3><a name="ap_regex" id="ap_regex">ap_regex (changed)</a></h3>
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  <p>In addition to the existing regexp wrapper, a new higher-level API
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  <code>ap_rxplus</code> is now provided.  This provides the capability to
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  compile Perl-style expressions like <code>s/regexp/replacement/flags</code>
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  and to execute them against arbitrary strings. Support for regexp
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  backreferences is also added.</p>
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  <h3><a name="ap_slotmem" id="ap_slotmem">ap_slotmem (NEW!)</a></h3>
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    <p>Introduces an API for modules to allocate and manage memory slots,
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    most commonly for shared memory.</p>
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  <h3><a name="ap_socache" id="ap_socache">ap_socache (NEW!)</a></h3>
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    <p>API to manage a shared object cache.</p>
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  <h3><a name="heartbeat" id="heartbeat">heartbeat (NEW!)</a></h3>
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    <p>common structures for heartbeat modules</p>
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  <h3><a name="ap_parse_htaccess" id="ap_parse_htaccess">ap_parse_htaccess (changed)</a></h3>
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    <p>The function signature for <code>ap_parse_htaccess</code> has been
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    changed. A <code>apr_table_t</code> of individual directives allowed
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    for override must now be passed (override remains).</p>
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  <h3><a name="http_config" id="http_config">http_config (changed)</a></h3>
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    <ul>
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      <li>Introduces per-module, per-directory loglevels, including macro wrappers.</li>
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      <li>New <code>AP_DECLARE_MODULE</code> macro to declare all modules.</li>
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      <li>New <code>APLOG_USE_MODULE</code> macro necessary for per-module loglevels in
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          multi-file modules.</li>
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      <li>New API to retain data across module unload/load</li>
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      <li>New <code>check_config</code> hook</li>
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      <li>New <code>ap_process_fnmatch_configs()</code> function to process wildcards</li>
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      <li>Change <code>ap_configfile_t</code>, <code>ap_cfg_getline()</code>, 
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          <code>ap_cfg_getc()</code> to return error codes, and add 
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          <code>ap_pcfg_strerror()</code> for retrieving an error description.</li> 
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      <li>Any config directive permitted in ACCESS_CONF context must now
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          correctly handle being called from an .htaccess file via the new
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          <code class="directive"><a href="../mod/core.html#allowoverridelist">AllowOverrideList</a></code> directive.
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          ap_check_cmd_context() accepts a new flag NOT_IN_HTACCESS to detect
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          this case.</li>
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    </ul>
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  <h3><a name="http_core" id="http_core">http_core (changed)</a></h3>
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    <ul>
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      <li>REMOVED <code>ap_default_type</code>, <code>ap_requires</code>, all 
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          2.2 authnz API</li>
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      <li>Introduces Optional Functions for logio and authnz</li>
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      <li>New function <code>ap_get_server_name_for_url</code> to support IPv6
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          literals.</li>
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      <li>New function <code>ap_register_errorlog_handler</code> to register error log
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          format string handlers.</li>
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      <li>Arguments of <code>error_log</code> hook have changed. Declaration has moved to
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          <code>http_core.h</code>.</li>
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      <li>New function <code>ap_state_query</code> to determine if the server is in the
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          initial configuration preflight phase or not. This is both easier to
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          use and more correct than the old method of creating a pool userdata
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          entry in the process pool.</li>
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      <li>New function <code>ap_get_conn_socket</code> to get the socket descriptor for a
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          connection. This should be used instead of accessing the core
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          connection config directly.</li>
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    </ul>
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  <h3><a name="httpd" id="httpd">httpd (changed)</a></h3>
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    <ul>
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      <li>Introduce per-directory, per-module loglevel</li>
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      <li>New loglevels <code>APLOG_TRACEn</code></li>
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      <li>Introduce errorlog ids for requests and connections</li>
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      <li>Support for mod_request kept_body</li>
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      <li>Support buffering filter data for async requests</li>
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      <li>New <code>CONN_STATE</code> values</li>
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      <li>Function changes: <code>ap_escape_html</code> updated; 
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          <code>ap_unescape_all</code>, <code>ap_escape_path_segment_buffer</code></li>
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      <li>Modules that load other modules later than the <code>EXEC_ON_READ</code> config
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          reading stage need to call <code>ap_reserve_module_slots()</code> or
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          <code>ap_reserve_module_slots_directive()</code> in their 
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          <code>pre_config hook</code>.</li>
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      <li>The useragent IP address per request can now be tracked
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          independently of the client IP address of the connection, for
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          support of deployments with load balancers.</li>
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    </ul>
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  <h3><a name="http_log" id="http_log">http_log (changed)</a></h3>
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    <ul>
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      <li>Introduce per-directory, per-module loglevel</li>
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      <li>New loglevels <code>APLOG_TRACEn</code></li>
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      <li><code>ap_log_*error</code> become macro wrappers (backwards-compatible if
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          <code>APLOG_MARK</code> macro is used, except that is no longer possible to
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          use <code>#ifdef</code> inside the argument list)</li>
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      <li>piped logging revamped</li>
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      <li><code>module_index</code> added to error_log hook</li>
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      <li>new function: <code>ap_log_command_line</code></li>
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    </ul>
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  <h3><a name="http_request" id="http_request">http_request (changed)</a></h3>
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    <ul>
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      <li>New auth_internal API and auth_provider API</li>
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      <li>New <code>EOR</code> bucket type</li>
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      <li>New function <code>ap_process_async_request</code></li>
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      <li>New flags <code>AP_AUTH_INTERNAL_PER_CONF</code> and 
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          <code>AP_AUTH_INTERNAL_PER_URI</code></li>
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      <li>New <code>access_checker_ex</code> hook to apply additional access control 
 | 
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          and/or bypass authentication.</li>
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      <li>New functions <code>ap_hook_check_access_ex</code>, 
 | 
						|
          <code>ap_hook_check_access</code>, <code>ap_hook_check_authn</code>, 
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          <code>ap_hook_check_authz</code> which accept 
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          <code>AP_AUTH_INTERNAL_PER_*</code> flags</li>
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      <li>DEPRECATED direct use of <code>ap_hook_access_checker</code>, 
 | 
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          <code>access_checker_ex</code>, <code>ap_hook_check_user_id</code>, 
 | 
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          <code>ap_hook_auth_checker</code></li>
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    </ul>
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    <p>When possible, registering all access control hooks (including
 | 
						|
       authentication and authorization hooks) using <code>AP_AUTH_INTERNAL_PER_CONF</code>
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						|
       is recommended.  If all modules' access control hooks are registered
 | 
						|
       with this flag, then whenever the server handles an internal
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       sub-request that matches the same set of access control configuration
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						|
       directives as the initial request (which is the common case), it can
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       avoid invoking the access control hooks another time.</p>
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    <p>If your module requires the old behavior and must perform access
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       control checks on every sub-request with a different URI from the
 | 
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       initial request, even if that URI matches the same set of access
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       control configuration directives, then use 
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       <code>AP_AUTH_INTERNAL_PER_URI</code>.</p>
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  <h3><a name="mod_auth" id="mod_auth">mod_auth (NEW!)</a></h3>
 | 
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    <p>Introduces the new provider framework for authn and authz</p>
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 | 
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  <h3><a name="mod_cache" id="mod_cache">mod_cache (changed)</a></h3>
 | 
						|
    
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    <p>Introduces a <code>commit_entity()</code> function to the cache provider 
 | 
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    interface, allowing atomic writes to cache. Add a <code>cache_status()</code>
 | 
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    hook to report the cache decision. All private structures and functions were
 | 
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    removed.</p>
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  <h3><a name="mod_core" id="mod_core">mod_core (NEW!)</a></h3>
 | 
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    <p>This introduces low-level APIs to send arbitrary headers,
 | 
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    and exposes functions to handle HTTP OPTIONS and TRACE.</p>
 | 
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  <h3><a name="mod_cache_disk" id="mod_cache_disk">mod_cache_disk (changed)</a></h3>
 | 
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    <p>Changes the disk format of the disk cache to support atomic cache
 | 
						|
    updates without locking. The device/inode pair of the body file is
 | 
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    embedded in the header file, allowing confirmation that the header
 | 
						|
    and body belong to one another.</p>
 | 
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  <h3><a name="mod_disk_cache" id="mod_disk_cache">mod_disk_cache (renamed)</a></h3>
 | 
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    <p>The mod_disk_cache module has been renamed to mod_cache_disk in
 | 
						|
    order to be consistent with the naming of other modules within the
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    server.</p>
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 | 
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  <h3><a name="mod_request" id="mod_request">mod_request (NEW!)</a></h3>
 | 
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 | 
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    <p>The API for <code class="module"><a href="../mod/mod_request.html">mod_request</a></code>, to make input data
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    available to multiple application/handler modules where required,
 | 
						|
    and to parse HTML form data.</p>
 | 
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 | 
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 | 
						|
  <h3><a name="mpm_common" id="mpm_common">mpm_common (changed)</a></h3>
 | 
						|
    
 | 
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    <ul>
 | 
						|
      <li>REMOVES: <code>accept</code>, <code>lockfile</code>, <code>lock_mech</code>,
 | 
						|
          <code>set_scoreboard</code> (locking uses the new ap_mutex API)</li>
 | 
						|
      <li>NEW API to drop privileges (delegates this platform-dependent
 | 
						|
          function to modules)</li>
 | 
						|
      <li>NEW Hooks: <code>mpm_query</code>, <code>timed_callback</code>, and 
 | 
						|
          <code>get_name</code></li>
 | 
						|
      <li>CHANGED interfaces: <code>monitor</code> hook,
 | 
						|
          <code>ap_reclaim_child_processes</code>, 
 | 
						|
          <code>ap_relieve_child_processes</code></li>
 | 
						|
    </ul>
 | 
						|
  
 | 
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 | 
						|
  <h3><a name="scoreboard" id="scoreboard">scoreboard (changed)</a></h3>
 | 
						|
    
 | 
						|
    <p><code>ap_get_scoreboard_worker</code> is made non-backwards-compatible
 | 
						|
    as an alternative version is introduced.  Additional proxy_balancer
 | 
						|
    support.  Child status stuff revamped.</p>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="util_cookies" id="util_cookies">util_cookies (NEW!)</a></h3>
 | 
						|
    
 | 
						|
    <p>Introduces a new API for managing HTTP Cookies.</p>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="util_ldap" id="util_ldap">util_ldap (changed)</a></h3>
 | 
						|
    
 | 
						|
    <p><em>no description available</em></p>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="util_mutex" id="util_mutex">util_mutex (NEW!)</a></h3>
 | 
						|
    
 | 
						|
    <p>A wrapper for APR proc and global mutexes in httpd, providing
 | 
						|
       common configuration for the underlying mechanism and location
 | 
						|
       of lock files.</p>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="util_script" id="util_script">util_script (changed)</a></h3>
 | 
						|
    
 | 
						|
    <p>NEW: <code>ap_args_to_table</code></p>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="util_time" id="util_time">util_time (changed)</a></h3>
 | 
						|
    
 | 
						|
    <p>NEW: <code>ap_recent_ctime_ex</code></p>
 | 
						|
  
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="upgrading" id="upgrading">Specific information on upgrading modules from 2.2</a></h2>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="upgrading_logging" id="upgrading_logging">Logging</a></h3>
 | 
						|
    
 | 
						|
    <p>In order to take advantage of per-module loglevel configuration, any
 | 
						|
       source file that calls the <code>ap_log_*</code> functions should declare
 | 
						|
       which module it belongs to. If the module's module_struct is called
 | 
						|
       <code>foo_module</code>, the following code can be used to remain
 | 
						|
       backward compatible with HTTPD 2.0 and 2.2:</p>
 | 
						|
    <div class="example"><p><code>
 | 
						|
        #include <http_log.h><br />
 | 
						|
        <br />
 | 
						|
        #ifdef APLOG_USE_MODULE<br />
 | 
						|
        APLOG_USE_MODULE(foo);<br />
 | 
						|
        #endif
 | 
						|
    </code></p></div>
 | 
						|
    <p>Note: This is absolutely required for C++-language modules.  It
 | 
						|
    can be skipped for C-language modules, though that breaks
 | 
						|
    module-specific log level support for files without it.</p>
 | 
						|
    <p>The number of parameters of the <code>ap_log_*</code> functions and the
 | 
						|
       definition of <code>APLOG_MARK</code> has changed. Normally, the change
 | 
						|
       is completely transparent. However, changes are required if a
 | 
						|
       module uses <code>APLOG_MARK</code> as a parameter to its own functions
 | 
						|
       or if a module calls <code>ap_log_*</code> without passing
 | 
						|
       <code>APLOG_MARK</code>.  A module which uses wrappers
 | 
						|
       around <code>ap_log_*</code> typically uses both of these constructs.</p>
 | 
						|
 | 
						|
    <p>The easiest way to change code which passes <code>APLOG_MARK</code> to
 | 
						|
       its own functions is to define and use a different macro that expands to
 | 
						|
       the parameters required by those functions, as <code>APLOG_MARK</code>
 | 
						|
       should only be used when calling <code>ap_log_*</code>
 | 
						|
       directly.  In this way, the code will remain compatible with HTTPD 2.0
 | 
						|
       and 2.2.</p>
 | 
						|
 | 
						|
    <p>Code which calls <code>ap_log_*</code> without passing
 | 
						|
       <code>APLOG_MARK</code> will necessarily differ between 2.4 and earlier
 | 
						|
       releases, as 2.4 requires a new third argument,
 | 
						|
       <code>APLOG_MODULE_INDEX</code>.</p>
 | 
						|
 | 
						|
    <div class="example"><p><code>
 | 
						|
       /* code for httpd 2.0/2.2 */<br />
 | 
						|
       ap_log_perror(file, line, APLOG_ERR, 0, p, "Failed to allocate dynamic lock structure");<br />
 | 
						|
       <br />
 | 
						|
       /* code for httpd 2.4 */<br />
 | 
						|
       ap_log_perror(file, line, APLOG_MODULE_INDEX, APLOG_ERR, 0, p, "Failed to allocate dynamic lock structure");<br />
 | 
						|
       <br />
 | 
						|
    </code></p></div>
 | 
						|
 | 
						|
    <p><code>ap_log_*error</code> are now implemented as macros. This means
 | 
						|
       that it is no longer possible to use <code>#ifdef</code> inside the
 | 
						|
       argument list of <code>ap_log_*error</code>, as this would cause
 | 
						|
       undefined behavor according to C99.</p>
 | 
						|
 | 
						|
    <p>A <code>server_rec</code> pointer must be passed to
 | 
						|
       <code>ap_log_error()</code> when called after startup.  This
 | 
						|
       was always appropriate, but there are even more limitations with
 | 
						|
       a <code>NULL</code> <code>server_rec</code> in 2.4 than in
 | 
						|
       previous releases.  Beginning with 2.3.12, the global variable
 | 
						|
       <code>ap_server_conf</code> can always be used as
 | 
						|
       the <code>server_rec</code> parameter, as it will be
 | 
						|
       <code>NULL</code> only when it is valid to pass <code>NULL</code>
 | 
						|
       to <code>ap_log_error()</code>.  <code>ap_server_conf</code>
 | 
						|
       should be used only when a more appropriate <code>server_rec</code>
 | 
						|
       is not available.</p>
 | 
						|
 | 
						|
    <p>Consider the following changes to take advantage of the new
 | 
						|
       <code>APLOG_TRACE1..8</code> log levels:</p>
 | 
						|
       <ul>
 | 
						|
         <li>Check current use of <code>APLOG_DEBUG</code> and
 | 
						|
         consider if one of the <code>APLOG_TRACEn</code> levels is
 | 
						|
         more appropriate.</li>
 | 
						|
         <li>If your module currently has a mechanism for configuring
 | 
						|
         the amount of debug logging which is performed, consider
 | 
						|
         eliminating that mechanism and relying on the use of
 | 
						|
         different <code>APLOG_TRACEn</code> levels.  If expensive
 | 
						|
         trace processing needs to be bypassed depending on the
 | 
						|
         configured log level, use the <code>APLOGtrace<em>n</em></code>
 | 
						|
         and <code>APLOGrtrace<em>n</em></code> macros to first check
 | 
						|
         if tracing is enabled.</li>
 | 
						|
       </ul>
 | 
						|
 | 
						|
    <p>Modules sometimes add process id and/or thread id to their log
 | 
						|
       messages.  These ids are now logged by default, so it may not
 | 
						|
       be necessary for the module to log them explicitly.  (Users may
 | 
						|
       remove them from the error log format, but they can be
 | 
						|
       instructed to add it back if necessary for problem diagnosis.)</p>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="upgrading_byfunction" id="upgrading_byfunction">If your module uses these existing APIs...</a></h3>
 | 
						|
    
 | 
						|
 | 
						|
    <dl>
 | 
						|
      <dt><code>ap_default_type()</code></dt>
 | 
						|
      <dd>This is no longer available; Content-Type must be configured
 | 
						|
          explicitly or added by the application.</dd>
 | 
						|
 | 
						|
      <dt><code>ap_get_server_name()</code></dt>
 | 
						|
      <dd>If the returned server name is used in a URL,
 | 
						|
      use <code>ap_get_server_name_for_url()</code> instead.  This new
 | 
						|
      function handles the odd case where the server name is an IPv6
 | 
						|
      literal address.</dd>
 | 
						|
 | 
						|
      <dt><code>ap_get_server_version()</code></dt>
 | 
						|
      <dd>For logging purposes, where detailed information is
 | 
						|
          appropriate, use <code>ap_get_server_description()</code>.
 | 
						|
          When generating output, where the amount of information
 | 
						|
          should be configurable by ServerTokens, use
 | 
						|
          <code>ap_get_server_banner()</code>.</dd>
 | 
						|
 | 
						|
      <dt><code>ap_graceful_stop_signalled()</code></dt>
 | 
						|
      <dd>Replace with a call
 | 
						|
      to <code>ap_mpm_query(AP_MPMQ_MPM_STATE)</code> and checking for
 | 
						|
      state <code>AP_MPMQ_STOPPING</code>.</dd>
 | 
						|
 | 
						|
      <dt><code>ap_max_daemons_limit</code>, <code>ap_my_generation</code>,
 | 
						|
          and <code>ap_threads_per_child</code></dt>
 | 
						|
      <dd>Use <code>ap_mpm_query()</code> query codes
 | 
						|
          <code>AP_MPMQ_MAX_DAEMON_USED</code>, <code>AP_MPMQ_GENERATION</code>,
 | 
						|
          and <code>AP_MPMQ_MAX_THREADS</code>, respectively.</dd>
 | 
						|
 | 
						|
      <dt><code>ap_mpm_query()</code></dt>
 | 
						|
      <dd>Ensure that it is not used until after the register-hooks
 | 
						|
          hook has completed.  Otherwise, an MPM built as a DSO
 | 
						|
          would not have had a chance to enable support for this
 | 
						|
          function.</dd>
 | 
						|
 | 
						|
      <dt><code>ap_server_conf->process->pool</code>
 | 
						|
      userdata</dt>
 | 
						|
      <dd>
 | 
						|
        Optional:
 | 
						|
        <ul>
 | 
						|
          <li>If your module uses this to determine which pass of the
 | 
						|
	  startup hooks is being run,
 | 
						|
	  use <code>ap_state_query(AP_SQ_MAIN_STATE)</code>.</li>
 | 
						|
          <li>If your module uses this to maintain data across the
 | 
						|
          unloading and reloading of your module, use
 | 
						|
          <code>ap_retained_data_create()</code> and
 | 
						|
          <code>ap_retained_data_get()</code>.</li>
 | 
						|
        </ul>
 | 
						|
      </dd>
 | 
						|
 | 
						|
      <dt><code>apr_global_mutex_create()</code>,
 | 
						|
          <code>apr_proc_mutex_create()</code></dt>
 | 
						|
      <dd>Optional: See <code>ap_mutex_register()</code>,
 | 
						|
          <code>ap_global_mutex_create()</code>, and
 | 
						|
          <code>ap_proc_mutex_create()</code>; these allow your
 | 
						|
          mutexes to be configurable with
 | 
						|
          the <code class="directive"><a href="../mod/core.html#mutex">Mutex</a></code> directive;
 | 
						|
          you can also remove any configuration mechanisms in your
 | 
						|
          module for such mutexes
 | 
						|
      </dd>
 | 
						|
 | 
						|
      <dt><code>CORE_PRIVATE</code></dt>
 | 
						|
      <dd>This is now unnecessary and ignored.</dd>
 | 
						|
 | 
						|
      <dt><code>dav_new_error()</code>
 | 
						|
      and <code>dav_new_error_tag()</code></dt>
 | 
						|
      <dd>Previously, these assumed that <code>errno</code> contained
 | 
						|
      information describing the failure.  Now,
 | 
						|
      an <code>apr_status_t</code> parameter must be provided.  Pass
 | 
						|
      0/APR_SUCCESS if there is no such error information, or a valid
 | 
						|
      <code>apr_status_t</code> value otherwise.</dd>
 | 
						|
 | 
						|
      <dt><code>mpm_default.h</code>, <code>DEFAULT_LOCKFILE</code>,
 | 
						|
      <code>DEFAULT_THREAD_LIMIT</code>, <code>DEFAULT_PIDLOG</code>,
 | 
						|
      etc.</dt>
 | 
						|
      <dd>The header file and most of the default configuration
 | 
						|
      values set in it are no longer visible to modules.  (Most can
 | 
						|
      still be overridden at build time.)  <code>DEFAULT_PIDLOG</code>
 | 
						|
      and <code>DEFAULT_REL_RUNTIMEDIR</code> are now universally
 | 
						|
      available via <code>ap_config.h</code>.</dd>
 | 
						|
 | 
						|
      <dt><code>unixd_config</code></dt>
 | 
						|
      <dd>This has been renamed to ap_unixd_config.</dd>
 | 
						|
 | 
						|
      <dt><code>conn_rec->remote_ip</code> and 
 | 
						|
          <code>conn_rec->remote_addr</code></dt>
 | 
						|
      <dd>These fields have been renamed in order to distinguish between 
 | 
						|
      the client IP address of the connection and the useragent IP address
 | 
						|
      of the request (potentially overridden by a load balancer or proxy).
 | 
						|
      References to either of these fields must be updated with one of the
 | 
						|
      following options, as appropriate for the module:
 | 
						|
      <ul>
 | 
						|
        <li>When you require the IP address of the user agent, which
 | 
						|
        might be connected directly to the server, or might optionally be
 | 
						|
        separated from the server by a transparent load balancer or
 | 
						|
        proxy, use <code>request_rec->useragent_ip</code> and
 | 
						|
        <code>request_rec->useragent_addr</code>.</li>
 | 
						|
        <li>When you require the IP address of the client that is
 | 
						|
        connected directly to the server, which might be the useragent or
 | 
						|
        might be the load balancer or proxy itself, use
 | 
						|
        <code>conn_rec->client_ip</code> and 
 | 
						|
        <code>conn_rec->client_addr</code>.</li>
 | 
						|
      </ul>
 | 
						|
      </dd>
 | 
						|
    </dl>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="upgrading_byfeature" id="upgrading_byfeature">If your module interfaces with this feature...</a></h3>
 | 
						|
    
 | 
						|
    <dl>
 | 
						|
      <dt>suEXEC</dt>
 | 
						|
      <dd>Optional: If your module logs an error
 | 
						|
          when <code>ap_unixd_config.suexec_enabled</code> is 0,
 | 
						|
          also log the value of the new
 | 
						|
          field <code>suexec_disabled_reason</code>, which contains an
 | 
						|
          explanation of why it is not available.</dd>
 | 
						|
 | 
						|
      <dt>Extended status data in the scoreboard</dt>
 | 
						|
      <dd>In previous releases, <code>ExtendedStatus</code> had to be
 | 
						|
          set to <code>On</code>, which in turn required that
 | 
						|
          mod_status was loaded.  In 2.4, just
 | 
						|
          set <code>ap_extended_status</code> to <code>1</code> in a
 | 
						|
          pre-config hook and the extended status data will be
 | 
						|
          available.</dd>
 | 
						|
    </dl>
 | 
						|
  
 | 
						|
 | 
						|
  <h3><a name="upgrading_newfeatures" id="upgrading_newfeatures">Does your module...</a></h3>
 | 
						|
    
 | 
						|
    <dl>
 | 
						|
    <dt>Parse query args</dt>
 | 
						|
    <dd>Consider if <code>ap_args_to_table()</code> would be
 | 
						|
    helpful.</dd>
 | 
						|
 | 
						|
    <dt>Parse form data...</dt>
 | 
						|
    <dd>Use <code>ap_parse_form_data()</code>.</dd>
 | 
						|
 | 
						|
    <dt>Check for request header fields <code>Content-Length</code>
 | 
						|
    and <code>Transfer-Encoding</code> to see if a body was
 | 
						|
    specified</dt>
 | 
						|
    <dd>Use <code>ap_request_has_body()</code>.</dd>
 | 
						|
 | 
						|
    <dt>Implement cleanups which clear pointer variables</dt>
 | 
						|
    <dd>Use <code>ap_pool_cleanup_set_null()</code>.</dd>
 | 
						|
    </dl>
 | 
						|
  
 | 
						|
 | 
						|
</div></div>
 | 
						|
<div class="bottomlang">
 | 
						|
<p><span>Available Languages: </span><a href="../en/developer/new_api_2_4.html" title="English"> en </a></p>
 | 
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</div><div id="footer">
 | 
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<p class="apache">Copyright 2012 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>
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