Standardized engine/lib/cache.php

git-svn-id: http://code.elgg.org/elgg/trunk@3547 36083f99-b078-4883-b0ff-0f9b5a30f544

1 files changed, 400 insertions, 405 deletions

diff --git a/engine/lib/cache.php b/engine/lib/cache.php
index e7ed6c73c..fd13bf3c7 100644
--- a/engine/lib/cache.php
+++ b/engine/lib/cache.php
@@ -1,439 +1,434 @@
 <?php
+/**
+ * Elgg cache
+ * Cache file interface for caching data.
+ *
+ * @package Elgg
+ * @subpackage API
+ * @author Curverider Ltd <info@elgg.com>
+ * @link http://elgg.org/
+ */
+
+/**
+ * ElggCache The elgg cache superclass.
+ * This defines the interface for a cache (wherever that cache is stored).
+ *
+ * @author Curverider Ltd <info@elgg.com>
+ * @package Elgg
+ * @subpackage API
+ */
+abstract class ElggCache implements
+	// Override for array access
+	ArrayAccess  {
 	/**
-	 * Elgg cache
-	 * Cache file interface for caching data.
-	 * 
-	 * @package Elgg
-	 * @subpackage API
-	 * @author Curverider Ltd <info@elgg.com>
-	 * @link http://elgg.org/
+	 * Variables for the cache object.
+	 *
+	 * @var array
 	 */
+	private $variables;
 
 	/**
-	 * ElggCache The elgg cache superclass.
-	 * This defines the interface for a cache (wherever that cache is stored).
-	 * 
-	 * @author Curverider Ltd <info@elgg.com>
-	 * @package Elgg
-	 * @subpackage API
+	 * Set the constructor.
 	 */
-	abstract class ElggCache implements
-		ArrayAccess // Override for array access
-	{
-		/**
-		 * Variables for the cache object.
-		 *
-		 * @var array
-		 */
-		private $variables;
-		
-		/**
-		 * Set the constructor.
-		 */
-		function __construct() { $this->variables = array(); }
-		
-		/**
-		 * Set a cache variable.
-		 *
-		 * @param string $variable
-		 * @param string $value
-		 */
-		public function set_variable($variable, $value) 
-		{
-			if (!is_array($this->variables))
-				$this->variables = array();
-			
-			$this->variables[$variable] = $value;	
-		}
-		
-		/**
-		 * Get variables for this cache.
-		 *
-		 * @param string $variable
-		 * @return mixed The variable or null;
-		 */
-		public function get_variable($variable) 
-		{
-			if (isset($this->variables[$variable]))
-				return $this->variables[$variable];
-				
-			return null; 
+	function __construct() {
+		$this->variables = array();
+	}
+
+	/**
+	 * Set a cache variable.
+	 *
+	 * @param string $variable
+	 * @param string $value
+	 */
+	public function set_variable($variable, $value) {
+		if (!is_array($this->variables)) {
+			$this->variables = array();
 		}
-		
-		/**
-		 * Class member get overloading, returning key using $this->load defaults.
-		 *
-		 * @param string $key
-		 * @return mixed
-		 */
-		function __get($key) { return $this->load($key); }
-		
-		/**
-		 * Class member set overloading, setting a key using $this->save defaults.
-		 *
-		 * @param string $key
-		 * @param mixed $value
-		 * @return mixed
-		 */
-		function __set($key, $value) { return $this->save($key, $value); }
-		
-		/**
-		 * Supporting isset, using $this->load() with default values.
-		 *
-		 * @param string $key The name of the attribute or metadata.
-		 * @return bool
-		 */
-		function __isset($key) { return (bool)$this->load($key); }
-		
-		/**
-		 * Supporting unsetting of magic attributes.
-		 *
-		 * @param string $key The name of the attribute or metadata.
-		 */
-		function __unset($key) { return $this->delete($key); }
-		
-		/**
-		 * Save data in a cache.
-		 *
-		 * @param string $key
-		 * @param string $data
-		 * @return bool
-		 */
-		abstract public function save($key, $data);
-		
-		/**
-		 * Load data from the cache using a given key.
-		 *
-		 * @param string $key
-		 * @param int $offset 
-		 * @param int $limit
-		 * @return mixed The stored data or false.
-		 */
-		abstract public function load($key, $offset = 0, $limit = null);
-		
-		/**
-		 * Invalidate a key
-		 *
-		 * @param string $key
-		 * @return bool
-		 */
-		abstract public function delete($key);
-		
-		/**
-		 * Clear out all the contents of the cache.
-		 *
-		 */
-		abstract public function clear();
-		
-		/**
-		 * Add a key only if it doesn't already exist. 
-		 * Implemented simply here, if you extend this class and your caching engine provides a better way then 
-		 * override this accordingly.
-		 *
-		 * @param string $key
-		 * @param string $data
-		 * @return bool
-		 */
-		public function add($key, $data)
-		{
-			if (!isset($this[$key])) 
-				return $this->save($key, $data);
-				
-			return false;
+
+		$this->variables[$variable] = $value;
+	}
+
+	/**
+	 * Get variables for this cache.
+	 *
+	 * @param string $variable
+	 * @return mixed The variable or null;
+	 */
+	public function get_variable($variable) {
+		if (isset($this->variables[$variable])) {
+			return $this->variables[$variable];
 		}
-		
-		// ARRAY ACCESS INTERFACE //////////////////////////////////////////////////////////
-		function offsetSet($key, $value)
-		{
-     		$this->save($key, $value);
- 		} 
- 		
- 		function offsetGet($key) 
- 		{
-   			return $this->load($key);
- 		} 
- 		
- 		function offsetUnset($key) 
- 		{
-   			if ( isset($this->key) ) {
-     			unset($this->key);
-   			}
- 		} 
- 		
- 		function offsetExists($offset) 
- 		{
-   			return isset($this->$offset);
- 		} 
+
+		return null;
 	}
-	
+
 	/**
-	 * Shared memory cache description.
-	 * Extends ElggCache with functions useful to shared memory style caches (static variables, memcache etc)
+	 * Class member get overloading, returning key using $this->load defaults.
+	 *
+	 * @param string $key
+	 * @return mixed
 	 */
-	abstract class ElggSharedMemoryCache extends ElggCache
-	{
-		/**
-		 * Namespace variable used to keep various bits of the cache
-		 * separate.
-		 *
-		 * @var string
-		 */
-		private $namespace;
-		
-		/**
-		 * Set the namespace of this cache.
-		 * This is useful for cache types (like memcache or static variables) where there is one large
-		 * flat area of memory shared across all instances of the cache.
-		 *
-		 * @param string $namespace
-		 */
-		public function setNamespace($namespace = "default") { $this->namespace = $namespace; }
-		/**
-		 * Get the namespace currently defined.
-		 *
-		 * @return string
-		 */
-		public function getNamespace() { return $this->namespace; }
+	function __get($key) {
+		return $this->load($key);
 	}
-	
+
 	/**
-	 * ElggStaticVariableCache
-	 * Dummy cache which stores values in a static array. Using this makes future replacements to other caching back 
-	 * ends (eg memcache) much easier.
-	 * 
-	 * @author Curverider Ltd <info@elgg.com>
-	 * @package Elgg
-	 * @subpackage API
+	 * Class member set overloading, setting a key using $this->save defaults.
+	 *
+	 * @param string $key
+	 * @param mixed $value
+	 * @return mixed
 	 */
-	class ElggStaticVariableCache extends ElggSharedMemoryCache
-	{
-		/**
-		 * The cache.
-		 *
-		 * @var unknown_type
-		 */
-		private static $__cache;
-		
-		/**
-		 * Create the variable cache.
-		 * 
-		 * This function creates a variable cache in a static variable in memory, optionally with a given namespace (to avoid overlap).
-		 *
-		 * @param string $namespace The namespace for this cache to write to - note, namespaces of the same name are shared!
-		 */
-		function __construct($namespace = 'default')
-		{	
-			$this->setNamespace($namespace);
-			$this->clear();
-		}
-		
-		public function save($key, $data) 
-		{
-			$namespace = $this->getNamespace();
-			
-			ElggStaticVariableCache::$__cache[$namespace][$key] = $data;
-			
-			return true;
+	function __set($key, $value) {
+		return $this->save($key, $value);
+	}
+
+	/**
+	 * Supporting isset, using $this->load() with default values.
+	 *
+	 * @param string $key The name of the attribute or metadata.
+	 * @return bool
+	 */
+	function __isset($key) {
+		return (bool)$this->load($key);
+	}
+
+	/**
+	 * Supporting unsetting of magic attributes.
+	 *
+	 * @param string $key The name of the attribute or metadata.
+	 */
+	function __unset($key) {
+		return $this->delete($key);
+	}
+
+	/**
+	 * Save data in a cache.
+	 *
+	 * @param string $key
+	 * @param string $data
+	 * @return bool
+	 */
+	abstract public function save($key, $data);
+
+	/**
+	 * Load data from the cache using a given key.
+	 *
+	 * @param string $key
+	 * @param int $offset
+	 * @param int $limit
+	 * @return mixed The stored data or false.
+	 */
+	abstract public function load($key, $offset = 0, $limit = null);
+
+	/**
+	 * Invalidate a key
+	 *
+	 * @param string $key
+	 * @return bool
+	 */
+	abstract public function delete($key);
+
+	/**
+	 * Clear out all the contents of the cache.
+	 *
+	 */
+	abstract public function clear();
+
+	/**
+	 * Add a key only if it doesn't already exist.
+	 * Implemented simply here, if you extend this class and your caching engine provides a better way then
+	 * override this accordingly.
+	 *
+	 * @param string $key
+	 * @param string $data
+	 * @return bool
+	 */
+	public function add($key, $data) {
+		if (!isset($this[$key])) {
+			return $this->save($key, $data);
 		}
-		
-		public function load($key, $offset = 0, $limit = null)
-		{
-			$namespace = $this->getNamespace();
-			
-			if (isset(ElggStaticVariableCache::$__cache[$namespace][$key]))
-				return ElggStaticVariableCache::$__cache[$namespace][$key];
-				
-			return false;
+
+		return false;
+	}
+
+	// ARRAY ACCESS INTERFACE //////////////////////////////////////////////////////////
+	function offsetSet($key, $value) {
+		$this->save($key, $value);
+	}
+
+	function offsetGet($key) {
+		return $this->load($key);
+	}
+
+	function offsetUnset($key) {
+		if ( isset($this->key) ) {
+			unset($this->key);
 		}
-		
-		public function delete($key) 
-		{
-			$namespace = $this->getNamespace();
-			
-			unset(ElggStaticVariableCache::$__cache[$namespace][$key]);
-			
-			return true;
+	}
+
+	function offsetExists($offset) {
+		return isset($this->$offset);
+	}
+}
+
+/**
+ * Shared memory cache description.
+ * Extends ElggCache with functions useful to shared memory style caches (static variables, memcache etc)
+ */
+abstract class ElggSharedMemoryCache extends ElggCache {
+	/**
+	 * Namespace variable used to keep various bits of the cache
+	 * separate.
+	 *
+	 * @var string
+	 */
+	private $namespace;
+
+	/**
+	 * Set the namespace of this cache.
+	 * This is useful for cache types (like memcache or static variables) where there is one large
+	 * flat area of memory shared across all instances of the cache.
+	 *
+	 * @param string $namespace
+	 */
+	public function setNamespace($namespace = "default") {
+		$this->namespace = $namespace;
+	}
+
+	/**
+	 * Get the namespace currently defined.
+	 *
+	 * @return string
+	 */
+	public function getNamespace() {
+		return $this->namespace;
+	}
+}
+
+/**
+ * ElggStaticVariableCache
+ * Dummy cache which stores values in a static array. Using this makes future replacements to other caching back
+ * ends (eg memcache) much easier.
+ *
+ * @author Curverider Ltd <info@elgg.com>
+ * @package Elgg
+ * @subpackage API
+ */
+class ElggStaticVariableCache extends ElggSharedMemoryCache {
+	/**
+	 * The cache.
+	 *
+	 * @var unknown_type
+	 */
+	private static $__cache;
+
+	/**
+	 * Create the variable cache.
+	 *
+	 * This function creates a variable cache in a static variable in memory, optionally with a given namespace (to avoid overlap).
+	 *
+	 * @param string $namespace The namespace for this cache to write to - note, namespaces of the same name are shared!
+	 */
+	function __construct($namespace = 'default') {
+		$this->setNamespace($namespace);
+		$this->clear();
+	}
+
+	public function save($key, $data) {
+		$namespace = $this->getNamespace();
+
+		ElggStaticVariableCache::$__cache[$namespace][$key] = $data;
+
+		return true;
+	}
+
+	public function load($key, $offset = 0, $limit = null) {
+		$namespace = $this->getNamespace();
+
+		if (isset(ElggStaticVariableCache::$__cache[$namespace][$key])) {
+			return ElggStaticVariableCache::$__cache[$namespace][$key];
 		}
-		
-		public function clear()
-		{
-			$namespace = $this->getNamespace();
-			
-			if (!isset(ElggStaticVariableCache::$__cache))
-				ElggStaticVariableCache::$__cache = array();
-				
-			//if (!isset(ElggStaticVariableCache::$__cache[$namespace]))
-				ElggStaticVariableCache::$__cache[$namespace] = array();
+
+		return false;
+	}
+
+	public function delete($key) {
+		$namespace = $this->getNamespace();
+
+		unset(ElggStaticVariableCache::$__cache[$namespace][$key]);
+
+		return true;
+	}
+
+	public function clear() {
+		$namespace = $this->getNamespace();
+
+		if (!isset(ElggStaticVariableCache::$__cache)) {
+			ElggStaticVariableCache::$__cache = array();
 		}
+
+		ElggStaticVariableCache::$__cache[$namespace] = array();
 	}
-	
+}
+
+/**
+ * ElggFileCache
+ * Store cached data in a file store.
+ *
+ * @author Curverider Ltd <info@elgg.com>
+ * @package Elgg
+ * @subpackage API
+ */
+class ElggFileCache extends ElggCache {
 	/**
-	 * ElggFileCache
-	 * Store cached data in a file store.
-	 * 
-	 * @author Curverider Ltd <info@elgg.com>
-	 * @package Elgg
-	 * @subpackage API
+	 * Set the Elgg cache.
+	 *
+	 * @param string $cache_path The cache path.
+	 * @param int $max_age Maximum age in seconds, 0 if no limit.
+	 * @param int $max_size Maximum size of cache in seconds, 0 if no limit.
 	 */
-	class ElggFileCache extends ElggCache
-	{
-		/**
-		 * Set the Elgg cache.
-		 *
-		 * @param string $cache_path The cache path.
-		 * @param int $max_age Maximum age in seconds, 0 if no limit.
-		 * @param int $max_size Maximum size of cache in seconds, 0 if no limit.
-		 */
-		function __construct($cache_path, $max_age = 0, $max_size = 0)
-		{
-			$this->set_variable("cache_path", $cache_path);
-			$this->set_variable("max_age", $max_age);
-			$this->set_variable("max_size", $max_size);	
-
-			if ($cache_path=="") throw new ConfigurationException(elgg_echo('ConfigurationException:NoCachePath'));
+	function __construct($cache_path, $max_age = 0, $max_size = 0) {
+		$this->set_variable("cache_path", $cache_path);
+		$this->set_variable("max_age", $max_age);
+		$this->set_variable("max_size", $max_size);
+
+		if ($cache_path=="") {
+			throw new ConfigurationException(elgg_echo('ConfigurationException:NoCachePath'));
 		}
-		
-		/**
-		 * Create and return a handle to a file.
-		 *
-		 * @param string $filename
-		 * @param string $rw
-		 */
-		protected function create_file($filename, $rw = "rb")
-		{
-			// Create a filename matrix
-			$matrix = "";
-			$depth = strlen($filename);
-			if ($depth > 5) $depth = 5;
-			 
-		//	for ($n = 0; $n < $depth; $n++)
-		//		$matrix .= $filename[$n] . "/";	
-				
-			// Create full path
-			$path = $this->get_variable("cache_path") . $matrix;
-			if (!is_dir($path))
-				mkdir($path, 0700, true);
-			
-	//		if (!mkdir($path, 0700, true)) throw new IOException("Could not make $path");
-			
-			// Open the file
-			if ((!file_exists($path . $filename)) && ($rw=="rb")) return false;
-			
-			return fopen($path . $filename, $rw);
+	}
+
+	/**
+	 * Create and return a handle to a file.
+	 *
+	 * @param string $filename
+	 * @param string $rw
+	 */
+	protected function create_file($filename, $rw = "rb") {
+		// Create a filename matrix
+		$matrix = "";
+		$depth = strlen($filename);
+		if ($depth > 5) {
+			$depth = 5;
 		}
-		
-		/**
-		 * Create a sanitised filename for the file.
-		 *
-		 * @param string $filename
-		 */
-		protected function sanitise_filename($filename)
-		{
-			// TODO : Writeme
-
-			return $filename;
+
+		// Create full path
+		$path = $this->get_variable("cache_path") . $matrix;
+		if (!is_dir($path)) {
+			mkdir($path, 0700, true);
 		}
-		
-		/**
-		 * Save a key
-		 *
-		 * @param string $key
-		 * @param string $data
-		 * @return boolean
-		 */
-		public function save($key, $data)
-		{
-			$f = $this->create_file($this->sanitise_filename($key), "wb");
-			if ($f)
-			{
-				$result = fwrite($f, $data);
-				fclose($f);
-				
-				return $result;
-			}
-			
+
+		// Open the file
+		if ((!file_exists($path . $filename)) && ($rw=="rb")) {
 			return false;
 		}
-		
-		/**
-		 * Load a key
-		 *
-		 * @param string $key
-		 * @param int $offset
-		 * @param int $limit
-		 * @return string
-		 */
-		public function load($key, $offset = 0, $limit = null)
-		{
-			$f = $this->create_file($this->sanitise_filename($key));
-			if ($f) 
-			{
-				//fseek($f, $offset);
-				if (!$limit) $limit = -1;
-				$data = stream_get_contents($f, $limit, $offset);
-				
-				fclose($f);
-				
-				return $data;
+
+		return fopen($path . $filename, $rw);
+	}
+
+	/**
+	 * Create a sanitised filename for the file.
+	 *
+	 * @param string $filename
+	 */
+	protected function sanitise_filename($filename) {
+		// TODO : Writeme
+
+		return $filename;
+	}
+
+	/**
+	 * Save a key
+	 *
+	 * @param string $key
+	 * @param string $data
+	 * @return boolean
+	 */
+	public function save($key, $data) {
+		$f = $this->create_file($this->sanitise_filename($key), "wb");
+		if ($f) {
+			$result = fwrite($f, $data);
+			fclose($f);
+
+			return $result;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Load a key
+	 *
+	 * @param string $key
+	 * @param int $offset
+	 * @param int $limit
+	 * @return string
+	 */
+	public function load($key, $offset = 0, $limit = null) {
+		$f = $this->create_file($this->sanitise_filename($key));
+		if ($f) {
+			//fseek($f, $offset);
+			if (!$limit) {
+				$limit = -1;
 			}
-			
-			return false;
+			$data = stream_get_contents($f, $limit, $offset);
+
+			fclose($f);
+
+			return $data;
 		}
-		
-		/**
-		 * Invalidate a given key.
-		 *
-		 * @param string $key
-		 * @return bool
-		 */
-		public function delete($key)
-		{
-			$dir = $this->get_variable("cache_path");
-			
-			return unlink($dir.$key);
+
+		return false;
+	}
+
+	/**
+	 * Invalidate a given key.
+	 *
+	 * @param string $key
+	 * @return bool
+	 */
+	public function delete($key) {
+		$dir = $this->get_variable("cache_path");
+
+		return unlink($dir.$key);
+	}
+
+	public function clear() {
+		// TODO : writeme
+	}
+
+	public function __destruct() {
+		// TODO: Check size and age, clean up accordingly
+		$size = 0;
+		$dir = $this->get_variable("cache_path");
+
+		// Short circuit if both size and age are unlimited
+		if (($this->get_variable("max_age")==0) && ($this->get_variable("max_size")==0)) {
+			return;
 		}
-		
-		public function clear()
-		{
-			// TODO : writeme
+
+		$exclude = array(".","..");
+
+		$files = scandir($dir);
+		if (!$files) {
+			throw new IOException(sprintf(elgg_echo('IOException:NotDirectory'), $dir));
 		}
-		
-		public function __destruct()
-		{
-			// TODO: Check size and age, clean up accordingly
-			$size = 0;
-			$dir = $this->get_variable("cache_path");
-			
-			// Short circuit if both size and age are unlimited
-			if (($this->get_variable("max_age")==0) && ($this->get_variable("max_size")==0))
-				return;
-			
-			$exclude = array(".","..");
-			
-			$files = scandir($dir);
-			if (!$files) throw new IOException(sprintf(elgg_echo('IOException:NotDirectory'), $dir));
-			
-			// Perform cleanup
-			foreach ($files as $f)
-			{
-				if (!in_array($f, $exclude))
-				{
-					$stat = stat($dir.$f);
-					
-					// Add size
-					$size .= $stat['size'];
-					
-					// Is this older than my maximum date?
-					if (($this->get_variable("max_age")>0) && (time() - $stat['mtime'] > $this->get_variable("max_age")))
-						unlink($dir.$f);
-					
-					
-					
-					// TODO: Size
-					
+
+		// Perform cleanup
+		foreach ($files as $f) {
+			if (!in_array($f, $exclude)) {
+				$stat = stat($dir.$f);
+
+				// Add size
+				$size .= $stat['size'];
+
+				// Is this older than my maximum date?
+				if (($this->get_variable("max_age")>0) && (time() - $stat['mtime'] > $this->get_variable("max_age"))) {
+					unlink($dir.$f);
 				}
+
+				// TODO: Size
 			}
 		}
 	}
-	
-?>
+}