Plugin loading can be an expensive operation. At its heart, it needs to loop through each prefix, then each path on the prefix, until it finds a file that matches -- and which defines the class expected. In cases where the file exists but does not define the class, an error will be added to the PHP error stack, which is also an expensive operation. The question then turns to: how can you keep the flexibility of plugins and also address performance?
Zend_Loader_PluginLoader offers an opt-in feature for
just this situation, a class file include cache. When enabled, it
will create a file that contains all successful includes which you
can then call from your bootstrap. Using this strategy, you can
greatly improve the performance of your production servers.
Example 520. Using the PluginLoader class file include cache
To use the class file include cache, simply drop the following code into your bootstrap:
<?php
$classFileIncCache = APPLICATION_PATH . '/../data/pluginLoaderCache.php';
if (file_exists($classFileIncCache)) {
include_once $classFileIncCache;
}
Zend_Loader_PluginLoader::setIncludeFileCache($classFileIncCache);
Obviously, the path and filename will vary based on your needs. This code should come as early as possible, to ensure that plugin-based components can make use of it.
During development, you may wish to disable the cache. One method for doing so is to use a configuration key for determining whether or not the plugin loader should cache.
<?php
$classFileIncCache = APPLICATION_PATH . '/../data/pluginLoaderCache.php';
if (file_exists($classFileIncCache)) {
include_once $classFileIncCache;
}
if ($config->enablePluginLoaderCache) {
Zend_Loader_PluginLoader::setIncludeFileCache($classFileIncCache);
}
This technique allows you to keep your modifications to your configuration file rather than code.