diff options
Diffstat (limited to 'zend/documentation/manual/core/en/performance.classloading.html')
| -rw-r--r-- | zend/documentation/manual/core/en/performance.classloading.html | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/zend/documentation/manual/core/en/performance.classloading.html b/zend/documentation/manual/core/en/performance.classloading.html new file mode 100644 index 0000000..726e4ac --- /dev/null +++ b/zend/documentation/manual/core/en/performance.classloading.html @@ -0,0 +1,441 @@ +<!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" xml:lang="en" lang="en"> +<head> + <meta http-equiv="content-type" content="text/html; charset=UTF-8"/> + <title>Class Loading - Zend Framework Manual</title> + +</head> +<body> +<table width="100%"> + <tr valign="top"> + <td width="85%"> + <table width="100%"> + <tr> + <td width="25%" style="text-align: left;"> + <a href="performance.introduction.html">Introduction</a> + </td> + + <td width="50%" style="text-align: center;"> + <div class="up"><span class="up"><a href="performance.html">Zend Gdata Performance Guide</a></span><br /> + <span class="home"><a href="manual.html">Programmer's Reference Guide</a></span></div> + </td> + + <td width="25%" style="text-align: right;"> + <div class="next" style="text-align: right; float: right;"><a href="performance.database.html">Zend_Db Performance</a></div> + </td> + </tr> + </table> +<hr /> +<div id="performance.classloading" class="section"><div class="info"><h1 class="title">Class Loading</h1></div> + + + <p class="para"> + Anyone who ever performs profiling of a Zend Framework application will + immediately recognize that class loading is relatively expensive in Zend + Framework. Between the sheer number of class files that need to be + loaded for many components, to the use of plugins that do not have a 1:1 + relationship between their class name and the file system, the various + calls to <span class="methodname">include_once()</span> and + <span class="methodname">require_once()</span> can be problematic. This chapter intends to provide + some concrete solutions to these issues. + </p> + + <div class="section" id="performance.classloading.includepath" name="performance.classloading.includepath"><div class="info"><h1 class="title">How can I optimize my include_path?</h1></div> + + + <p class="para"> + One trivial optimization you can do to increase the speed of class + loading is to pay careful attention to your include_path. In + particular, you should do four things: use absolute paths (or paths + relative to absolute paths), reduce the number of include paths you + define, have your Zend Framework include_path as early as possible, + and only include the current directory path at the end of your + include_path. + </p> + + <div class="section" id="performance.classloading.includepath.abspath" name="performance.classloading.includepath.abspath"><div class="info"><h1 class="title">Use absolute paths</h1></div> + + + <p class="para"> + While this may seem a micro-optimization, the fact is that if + you don't, you'll get very little benefit from <acronym class="acronym">PHP</acronym>'s realpath + cache, and as a result, opcode caching will not perform nearly + as you may expect. + </p> + + <p class="para"> + There are two easy ways to ensure this. First, you can hardcode + the paths in your <var class="filename">php.ini</var>, <var class="filename">httpd.conf</var>, + or <var class="filename">.htaccess</var>. Second, you + can use <acronym class="acronym">PHP</acronym>'s <span class="methodname">realpath()</span> function when + setting your include_path: + </p> + + <div class="programlisting php"><div class="phpcode"><div class="php" style="font-family: monospace;"><ol><li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><span style="color: #0000ff;">$paths</span> = <a href="http://www.php.net/array"><span style="color: #000066;">array</span></a><span style="color: #66cc66;">(</span></div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> <a href="http://www.php.net/realpath"><span style="color: #000066;">realpath</span></a><span style="color: #66cc66;">(</span><a href="http://www.php.net/dirname"><span style="color: #000066;">dirname</span></a><span style="color: #66cc66;">(</span><span style="color: #000000; font-weight: bold;">__FILE__</span><span style="color: #66cc66;">)</span> . <span style="color: #ff0000;">'/../library'</span><span style="color: #66cc66;">)</span>,</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> <span style="color: #ff0000;">'.'</span>,</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><span style="color: #66cc66;">)</span>;</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><a href="http://www.php.net/set_include_path"><span style="color: #000066;">set_include_path</span></a><span style="color: #66cc66;">(</span><a href="http://www.php.net/implode"><span style="color: #000066;">implode</span></a><span style="color: #66cc66;">(</span>PATH_SEPARATOR, <span style="color: #0000ff;">$paths</span><span style="color: #66cc66;">)</span>;</div></li></ol></div></div></div> + + + <p class="para"> + You <em class="emphasis">can</em> use relative paths -- so long as + they are relative to an absolute path: + </p> + + <div class="programlisting php"><div class="phpcode"><div class="php" style="font-family: monospace;"><ol><li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><a href="http://www.php.net/define"><span style="color: #000066;">define</span></a><span style="color: #66cc66;">(</span><span style="color: #ff0000;">'APPLICATION_PATH'</span>, <a href="http://www.php.net/realpath"><span style="color: #000066;">realpath</span></a><span style="color: #66cc66;">(</span><a href="http://www.php.net/dirname"><span style="color: #000066;">dirname</span></a><span style="color: #66cc66;">(</span><span style="color: #000000; font-weight: bold;">__FILE__</span><span style="color: #66cc66;">)</span><span style="color: #66cc66;">)</span><span style="color: #66cc66;">)</span>;</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><span style="color: #0000ff;">$paths</span> = <a href="http://www.php.net/array"><span style="color: #000066;">array</span></a><span style="color: #66cc66;">(</span></div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> APPLICATION_PATH . <span style="color: #ff0000;">'/../library'</span><span style="color: #66cc66;">)</span>,</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> <span style="color: #ff0000;">'.'</span>,</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><span style="color: #66cc66;">)</span>;</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><a href="http://www.php.net/set_include_path"><span style="color: #000066;">set_include_path</span></a><span style="color: #66cc66;">(</span><a href="http://www.php.net/implode"><span style="color: #000066;">implode</span></a><span style="color: #66cc66;">(</span>PATH_SEPARATOR, <span style="color: #0000ff;">$paths</span><span style="color: #66cc66;">)</span>;</div></li></ol></div></div></div> + + + <p class="para"> + However, even so, it's typically a trivial task to simply pass + the path to <span class="methodname">realpath()</span>. + </p> + </div> + + <div class="section" id="performance.classloading.includepath.reduce" name="performance.classloading.includepath.reduce"><div class="info"><h1 class="title">Reduce the number of include paths you define</h1></div> + + + <p class="para"> + Include paths are scanned in the order in which they appear in + the include_path. Obviously, this means that you'll get a result + faster if the file is found on the first scan rather than the + last. Thus, a rather obvious enhancement is to simply reduce the + number of paths in your include_path to only what you need. Look + through each include_path you've defined, and determine if you + actually have any functionality in that path that is used in + your application; if not, remove it. + </p> + + <p class="para"> + Another optimization is to combine paths. For instance, Zend + Framework follows <acronym class="acronym">PEAR</acronym> naming conventions; thus, if you are + using <acronym class="acronym">PEAR</acronym> libraries (or libraries from another framework or + component library that follows <acronym class="acronym">PEAR</acronym> CS), try to put all of these + libraries on the same include_path. This can often be achieved + by something as simple as symlinking one or more libraries into + a common directory. + </p> + </div> + + <div class="section" id="performance.classloading.includepath.early" name="performance.classloading.includepath.early"><div class="info"><h1 class="title">Define your Zend Framework include_path as early as possible</h1></div> + + + <p class="para"> + Continuing from the previous suggestion, another obvious + optimization is to define your Zend Framework include_path as + early as possible in your include_path. In most cases, it should + be the first path in the list. This ensures that files included + from Zend Framework are found on the first scan. + </p> + </div> + + <div class="section" id="performance.classloading.includepath.currentdir" name="performance.classloading.includepath.currentdir"><div class="info"><h1 class="title">Define the current directory last, or not at all</h1></div> + + + <p class="para"> + Most include_path examples show using the current directory, or + '.'. This is convenient for ensuring that scripts in the same + directory as the file requiring them can be loaded. However, + these same examples typically show this path item as the first + item in the include_path -- which means that the current + directory tree is always scanned first. In most cases, with Zend + Framework applications, this is not desired, and the path may be + safely pushed to the last item in the list. + </p> + + <div class="example"><div class="info"><p><b>Example #1 Example: Optimized include_path</b></p></div> + + + <div class="example-contents"><p> + Let's put all of these suggestions together. Our assumption will be that you + are using one or more <acronym class="acronym">PEAR</acronym> libraries in conjunction with + Zend Framework -- perhaps the PHPUnit and <span class="classname">Archive_Tar</span> + libraries -- and that you occasionally need to include + files relative to the current file. + </p></div> + + <div class="example-contents"><p> + First, we'll create a library directory in our project. Inside that + directory, we'll symlink our Zend Framework's <var class="filename">library/Zend</var> + directory, as well as the necessary directories from our <acronym class="acronym">PEAR</acronym> + installation: + </p></div> + + <div class="programlisting php"><div class="phpcode"><div class="php" style="font-family: monospace;"><ol><li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;">library</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> Archive/</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> PEAR/</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> PHPUnit/</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> Zend/</div></li></ol></div></div></div> + + + <div class="example-contents"><p> + This allows us to add our own library code if necessary, while + keeping shared libraries intact. + </p></div> + + <div class="example-contents"><p> + Next, we'll opt to create our include_path programmatically + within our <var class="filename">public/index.php</var> file. This allows us to move + our code around on the file system, without needing to edit the + include_path every time. + </p></div> + + <div class="example-contents"><p> + We'll borrow ideas from each of the suggestions above: we'll use + absolute paths, as determined using <span class="methodname">realpath()</span>; + we'll include Zend Framework's include path early; we've + already consolidated include_paths; and we'll put the current + directory as the last path. In fact, we're doing really well + here -- we're going to end up with only two paths. + </p></div> + + <div class="programlisting php"><div class="phpcode"><div class="php" style="font-family: monospace;"><ol><li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><span style="color: #0000ff;">$paths</span> = <a href="http://www.php.net/array"><span style="color: #000066;">array</span></a><span style="color: #66cc66;">(</span></div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> <a href="http://www.php.net/realpath"><span style="color: #000066;">realpath</span></a><span style="color: #66cc66;">(</span><a href="http://www.php.net/dirname"><span style="color: #000066;">dirname</span></a><span style="color: #66cc66;">(</span><span style="color: #000000; font-weight: bold;">__FILE__</span><span style="color: #66cc66;">)</span> . <span style="color: #ff0000;">'/../library'</span><span style="color: #66cc66;">)</span>,</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> <span style="color: #ff0000;">'.'</span></div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><span style="color: #66cc66;">)</span>;</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><a href="http://www.php.net/set_include_path"><span style="color: #000066;">set_include_path</span></a><span style="color: #66cc66;">(</span><a href="http://www.php.net/implode"><span style="color: #000066;">implode</span></a><span style="color: #66cc66;">(</span>PATH_SEPARATOR, <span style="color: #0000ff;">$paths</span><span style="color: #66cc66;">)</span><span style="color: #66cc66;">)</span>;</div></li></ol></div></div></div> + + </div> + </div> + </div> + + <div class="section" id="performance.classloading.striprequires" name="performance.classloading.striprequires"><div class="info"><h1 class="title">How can I eliminate unnecessary require_once statements?</h1></div> + + + <p class="para"> + Lazy loading is an optimization technique designed to push the + expensive operation of loading a class file until the last possible + moment -- i.e., when instantiating an object of that class, calling + a static class method, or referencing a class constant or static + property. <acronym class="acronym">PHP</acronym> supports this via autoloading, which allows you to + define one or more callbacks to execute in order to map a class name + to a file. + </p> + + <p class="para"> + However, most benefits you may reap from autoloading are negated if + your library code is still performing <span class="methodname">require_once()</span> calls -- + which is precisely the case with Zend Framework. So, the question is: how can + you eliminate those <span class="methodname">require_once()</span> calls in order to maximize + autoloader performance? + </p> + + <div class="section" id="performance.classloading.striprequires.sed" name="performance.classloading.striprequires.sed"><div class="info"><h1 class="title">Strip require_once calls with find and sed</h1></div> + + + <p class="para"> + An easy way to strip <span class="methodname">require_once()</span> calls is to use the + <acronym class="acronym">UNIX</acronym> utilities 'find' and 'sed' in conjunction to comment out + each call. Try executing the following statements (where '%' + indicates the shell prompt): + </p> + + <div class="programlisting shell"><div class="shellcode"><div style="font-family: monospace;"><ol><li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;">% cd path/to/ZendFramework/library</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;">% find . -name '*.php' -not -wholename '*/Loader/Autoloader.php' \</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> -not -wholename '*/Application.php' -print0 | \</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"> xargs -0 sed --regexp-extended --in-place 's/(require_once)/\/\/ \1/g'</div></li></ol></div></div></div> + + + <p class="para"> + This one-liner (broken into two lines for readability) iterates + through each <acronym class="acronym">PHP</acronym> file and tells it to replace each instance of + 'require_once' with '// require_once', effectively commenting + out each such statement. (It selectively keeps + <span class="methodname">require_once()</span> calls within + <span class="classname">Zend_Application</span> and + <span class="classname">Zend_Loader_Autoloader</span>, as these classes will fail without + them.) + </p> + + <p class="para"> + This command could be added to an automated build or release + process trivially, helping boost performance in your production + application. It should be noted, however, that if you use this + technique, you <em class="emphasis">must</em> utilize autoloading; + you can do that from your "<var class="filename">public/index.php</var>" file with the + following code: + </p> + + <div class="programlisting php"><div class="phpcode"><div class="php" style="font-family: monospace;"><ol><li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;"><span style="color: #b1b100;">require_once</span> <span style="color: #ff0000;">'Zend/Loader/Autoloader.php'</span>;</div></li> +<li style="font-family: 'Courier New', Courier, monospace; color: black; font-weight: normal; font-style: normal;"><div style="font-family: 'Courier New', Courier, monospace; font-weight: normal;">Zend_Loader_Autoloader::<span style="color: #006600;">getInstance</span><span style="color: #66cc66;">(</span><span style="color: #66cc66;">)</span>;</div></li></ol></div></div></div> + + </div> + </div> + + <div class="section" id="performance.classloading.pluginloader" name="performance.classloading.pluginloader"><div class="info"><h1 class="title">How can I speed up plugin loading?</h1></div> + + + <p class="para"> + Many components have plugins, which allow you to create your own + classes to utilize with the component, as well as to override + existing, standard plugins shipped with Zend Framework. This + provides important flexibility to the framework, but at a price: + plugin loading is a fairly expensive task. + </p> + + <p class="para"> + The plugin loader allows you to register class prefix / path pairs, + allowing you to specify class files in non-standard paths. Each + prefix can have multiple paths associated with it. + Internally, the plugin loader loops through each prefix, and then + through each path attached to it, testing to see if the file exists + and is readable on that path. It then loads it, and tests to see + that the class it is looking for is available. As you might imagine, + this can lead to many stat calls on the file system. + </p> + + <p class="para"> + Multiply this by the number of components that use the PluginLoader, + and you get an idea of the scope of this issue. At the time of this + writing, the following components made use of the PluginLoader: + </p> + + <ul class="itemizedlist"> + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_Controller_Action_HelperBroker</span>: helpers + </p> + </li> + + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_Dojo</span>: view helpers, form elements and decorators + </p> + </li> + + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_File_Transfer</span>: adapters + </p> + </li> + + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_Filter_Inflector</span>: filters (used by the + ViewRenderer action helper and <span class="classname">Zend_Layout</span>) + </p> + </li> + + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_Filter_Input</span>: filters and validators + </p> + </li> + + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_Form</span>: elements, validators, filters, + decorators, captcha and file transfer adapters + </p> + </li> + + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_Paginator</span>: adapters + </p> + </li> + + <li class="listitem"> + <p class="para"> + <span class="classname">Zend_View</span>: helpers, filters + </p> + </li> + </ul> + + <p class="para"> + How can you reduce the number of such calls made? + </p> + + <div class="section" id="performance.classloading.pluginloader.includefilecache" name="performance.classloading.pluginloader.includefilecache"><div class="info"><h1 class="title">Use the PluginLoader include file cache</h1></div> + + + <p class="para"> + Zend Framework 1.7.0 adds an include file cache to the + PluginLoader. This functionality writes " <span class="methodname">include_once()</span>" + calls to a file, which you can then include in your bootstrap. While this + introduces extra <span class="methodname">include_once()</span> calls to your code, it + also ensures that the PluginLoader returns as early as possible. + </p> + + <p class="para"> + The PluginLoader documentation <a href="" class="link">includes + a complete example of its use</a>. + </p> + </div> + </div> +</div> + <hr /> + + <table width="100%"> + <tr> + <td width="25%" style="text-align: left;"> + <a href="performance.introduction.html">Introduction</a> + </td> + + <td width="50%" style="text-align: center;"> + <div class="up"><span class="up"><a href="performance.html">Zend Gdata Performance Guide</a></span><br /> + <span class="home"><a href="manual.html">Programmer's Reference Guide</a></span></div> + </td> + + <td width="25%" style="text-align: right;"> + <div class="next" style="text-align: right; float: right;"><a href="performance.database.html">Zend_Db Performance</a></div> + </td> + </tr> + </table> +</td> + <td style="font-size: smaller;" width="15%"> <style type="text/css"> +#leftbar { + float: left; + width: 186px; + padding: 5px; + font-size: smaller; +} +ul.toc { + margin: 0px 5px 5px 5px; + padding: 0px; +} +ul.toc li { + font-size: 85%; + margin: 1px 0 1px 1px; + padding: 1px 0 1px 11px; + list-style-type: none; + background-repeat: no-repeat; + background-position: center left; +} +ul.toc li.header { + font-size: 115%; + padding: 5px 0px 5px 11px; + border-bottom: 1px solid #cccccc; + margin-bottom: 5px; +} +ul.toc li.active { + font-weight: bold; +} +ul.toc li a { + text-decoration: none; +} +ul.toc li a:hover { + text-decoration: underline; +} +</style> + <ul class="toc"> + <li class="header home"><a href="manual.html">Programmer's Reference Guide</a></li> + <li class="header up"><a href="manual.html">Programmer's Reference Guide</a></li> + <li class="header up"><a href="performance.html">Zend Gdata Performance Guide</a></li> + <li><a href="performance.introduction.html">Introduction</a></li> + <li class="active"><a href="performance.classloading.html">Class Loading</a></li> + <li><a href="performance.database.html">Zend_Db Performance</a></li> + <li><a href="performance.localization.html">Internationalization (i18n) and Localization (l10n)</a></li> + <li><a href="performance.view.html">View Rendering</a></li> + </ul> + </td> + </tr> +</table> +</body> +</html>
\ No newline at end of file |