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Diffstat (limited to 'library/Icinga/Application/ClassLoader.php')
| -rw-r--r-- | library/Icinga/Application/ClassLoader.php | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/library/Icinga/Application/ClassLoader.php b/library/Icinga/Application/ClassLoader.php new file mode 100644 index 0000000..aed26f7 --- /dev/null +++ b/library/Icinga/Application/ClassLoader.php @@ -0,0 +1,334 @@ +<?php +/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */ + +namespace Icinga\Application; + +use Zend_Loader_Autoloader; + +/** + * PSR-4 class loader + */ +class ClassLoader +{ + /** + * Namespace separator + */ + const NAMESPACE_SEPARATOR = '\\'; + + /** + * Icinga Web 2 module namespace prefix + */ + const MODULE_PREFIX = 'Icinga\\Module\\'; + + /** + * Icinga Web 2 module namespace prefix length + * + * Helps to make substr/strpos operations even faster + */ + const MODULE_PREFIX_LENGTH = 14; + + /** + * A hardcoded class/subdir map for application ns prefixes + * + * When a module registers with an application directory, those + * namespace prefixes (after the module prefix) will be looked up + * in the corresponding application subdirectories + * + * @var array + */ + protected $applicationPrefixes = array( + 'Clicommands' => 'clicommands', + 'Controllers' => 'controllers', + 'Forms' => 'forms' + ); + + /** + * Whether we already instantiated the ZF autoloader + * + * @var boolean + */ + protected $gotZend = false; + + /** + * Namespaces + * + * @var array + */ + private $namespaces = array(); + + /** + * Application directories + * + * @var array + */ + private $applicationDirectories = array(); + + /** + * Register a base directory for a namespace prefix + * + * Application directory is optional and provides additional lookup + * logic for hardcoded namespaces like "Forms" + * + * @param string $namespace + * @param string $directory + * @param string $appDirectory + * + * @return $this + */ + public function registerNamespace($namespace, $directory, $appDirectory = null) + { + $this->namespaces[$namespace] = $directory; + + if ($appDirectory !== null) { + $this->applicationDirectories[$namespace] = $appDirectory; + } + + return $this; + } + + /** + * Test whether a namespace exists + * + * @param string $namespace + * + * @return bool + */ + public function hasNamespace($namespace) + { + return array_key_exists($namespace, $this->namespaces); + } + + /** + * Get the source file of the given class or interface + * + * @param string $class Name of the class or interface + * + * @return string|null + */ + public function getSourceFile($class) + { + if ($file = $this->getModuleSourceFile($class)) { + return $file; + } + + foreach ($this->namespaces as $namespace => $dir) { + if ($class === strstr($class, "$namespace\\")) { + return $this->buildClassFilename($class, $namespace); + } + } + + return null; + } + + /** + * Get the source file of the given module class or interface + * + * @param string $class Module class or interface name + * + * @return string|null + */ + protected function getModuleSourceFile($class) + { + if (! $this->classBelongsToModule($class)) { + return null; + } + + $modules = Icinga::app()->getModuleManager(); + $namespace = $this->extractModuleNamespace($class); + + if ($this->hasNamespace($namespace)) { + return $this->buildClassFilename($class, $namespace); + } elseif (! $modules->loadedAllEnabledModules()) { + $moduleName = $this->extractModuleName($class); + + if ($modules->hasEnabled($moduleName)) { + $modules->loadModule($moduleName); + + return $this->buildClassFilename($class, $namespace); + } + } + + return null; + } + + /** + * Extract the Icinga module namespace from a given namespaced class name + * + * Does no validation, prefix must have been checked before + * + * @return string + */ + protected function extractModuleNamespace($class) + { + return substr( + $class, + 0, + strpos($class, self::NAMESPACE_SEPARATOR, self::MODULE_PREFIX_LENGTH + 1) + ); + } + + /** + * Extract the Icinga module name from a given namespaced class name + * + * Does no validation, prefix must have been checked before + * + * @return string + */ + public static function extractModuleName($class) + { + return lcfirst( + substr( + $class, + self::MODULE_PREFIX_LENGTH, + strpos( + $class, + self::NAMESPACE_SEPARATOR, + self::MODULE_PREFIX_LENGTH + 1 + ) - self::MODULE_PREFIX_LENGTH + ) + ); + } + + /** + * Whether the given class name belongs to a module namespace + * + * @return boolean + */ + public static function classBelongsToModule($class) + { + return substr($class, 0, self::MODULE_PREFIX_LENGTH) === self::MODULE_PREFIX; + } + + /** + * Prepare a filename string for the given class + * + * Expects the given namespace to be registered with a path name + * + * @return string + */ + protected function buildClassFilename($class, $namespace) + { + $relNs = substr($class, strlen($namespace) + 1); + + if ($this->namespaceHasApplictionDirectory($namespace)) { + $prefixSeparator = strpos($relNs, self::NAMESPACE_SEPARATOR); + $prefix = substr($relNs, 0, $prefixSeparator); + + if ($this->isApplicationPrefix($prefix)) { + return $this->applicationDirectories[$namespace] + . DIRECTORY_SEPARATOR + . $this->applicationPrefixes[$prefix] + . $this->classToRelativePhpFilename(substr($relNs, $prefixSeparator)); + } + } + + return $this->namespaces[$namespace] . DIRECTORY_SEPARATOR . $this->classToRelativePhpFilename($relNs); + } + + /** + * Return the relative file name for the given (namespaces) class + * + * @param string $class + * + * @return string + */ + protected function classToRelativePhpFilename($class) + { + return str_replace( + self::NAMESPACE_SEPARATOR, + DIRECTORY_SEPARATOR, + $class + ) . '.php'; + } + + /** + * Whether given prefix (Forms, Controllers...) makes part of "application" + * + * @param string $prefix + * + * @return boolean + */ + protected function isApplicationPrefix($prefix) + { + return array_key_exists($prefix, $this->applicationPrefixes); + } + + /** + * Whether the given namespace registered an application directory + * + * @return boolean + */ + protected function namespaceHasApplictionDirectory($namespace) + { + return array_key_exists($namespace, $this->applicationDirectories); + } + + /** + * Require ZF autoloader + * + * @return Zend_Loader_Autoloader + */ + protected function requireZendAutoloader() + { + require_once 'Zend/Loader/Autoloader.php'; + $this->gotZend = true; + return Zend_Loader_Autoloader::getInstance(); + } + + /** + * Load the given class or interface + * + * @param string $class Name of the class or interface + * + * @return bool Whether the class or interface has been loaded + */ + public function loadClass($class) + { + // We are aware of the Zend_ prefix and lazyload it's autoloader. + // Return as fast as possible if we already did so. + if (substr($class, 0, 5) === 'Zend_') { + if (! $this->gotZend) { + $zendLoader = $this->requireZendAutoloader(); + if (version_compare(PHP_VERSION, '7.0.0') >= 0) { + // PHP7 seems to remember the autoload function stack before auto-loading. Thus + // autoload functions registered during autoload never get called + return $zendLoader::autoload($class); + } + } + return false; + } + + if ($file = $this->getSourceFile($class)) { + if (file_exists($file)) { + require $file; + return true; + } + } + + return false; + } + + /** + * Register {@link loadClass()} as an autoloader + */ + public function register() + { + spl_autoload_register(array($this, 'loadClass')); + } + + /** + * Unregister {@link loadClass()} as an autoloader + */ + public function unregister() + { + spl_autoload_unregister(array($this, 'loadClass')); + } + + /** + * Unregister this as an autoloader + */ + public function __destruct() + { + $this->unregister(); + } +} |