1 files changed, 243 insertions, 0 deletions
diff --git a/engine/classes/ElggCache.php b/engine/classes/ElggCache.php
new file mode 100644
index 000000000..4317f4be9
--- /dev/null
+++ b/engine/classes/ElggCache.php
@@ -0,0 +1,243 @@
+<?php
+/**
+ * ElggCache The elgg cache superclass.
+ * This defines the interface for a cache (wherever that cache is stored).
+ *
+ * @package    Elgg.Core
+ * @subpackage Cache
+ */
+abstract class ElggCache implements ArrayAccess {
+	/**
+	 * Variables for the cache object.
+	 *
+	 * @var array
+	 */
+	private $variables;
+
+	/**
+	 * Set the constructor.
+	 */
+	function __construct() {
+		$this->variables = array();
+	}
+
+	/**
+	 * Set a cache variable.
+	 *
+	 * @param string $variable Name
+	 * @param string $value    Value
+	 *
+	 * @return void
+	 *
+	 * @deprecated 1.8 Use ElggCache:setVariable()
+	 */
+	public function set_variable($variable, $value) {
+		elgg_deprecated_notice('ElggCache::set_variable() is deprecated by ElggCache::setVariable()', 1.8);
+		$this->setVariable($variable, $value);
+	}
+
+	/**
+	 * Set a cache variable.
+	 *
+	 * @param string $variable Name
+	 * @param string $value    Value
+	 *
+	 * @return void
+	 */
+	public function setVariable($variable, $value) {
+		if (!is_array($this->variables)) {
+			$this->variables = array();
+		}
+
+		$this->variables[$variable] = $value;
+	}
+
+	/**
+	 * Get variables for this cache.
+	 *
+	 * @param string $variable Name
+	 *
+	 * @return mixed The value or null;
+	 *
+	 * @deprecated 1.8 Use ElggCache::getVariable()
+	 */
+	public function get_variable($variable) {
+		elgg_deprecated_notice('ElggCache::get_variable() is deprecated by ElggCache::getVariable()', 1.8);
+		return $this->getVariable($variable);
+	}
+
+	/**
+	 * Get variables for this cache.
+	 *
+	 * @param string $variable Name
+	 *
+	 * @return mixed The variable or null;
+	 */
+	public function getVariable($variable) {
+		if (isset($this->variables[$variable])) {
+			return $this->variables[$variable];
+		}
+
+		return null;
+	}
+
+	/**
+	 * Class member get overloading, returning key using $this->load defaults.
+	 *
+	 * @param string $key Name
+	 *
+	 * @return mixed
+	 */
+	function __get($key) {
+		return $this->load($key);
+	}
+
+	/**
+	 * Class member set overloading, setting a key using $this->save defaults.
+	 *
+	 * @param string $key   Name
+	 * @param mixed  $value Value
+	 *
+	 * @return mixed
+	 */
+	function __set($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 $key The name of the attribute or metadata.
+	 *
+	 * @return bool
+	 */
+	function __unset($key) {
+		return $this->delete($key);
+	}
+
+	/**
+	 * Save data in a cache.
+	 *
+	 * @param string $key  Name
+	 * @param string $data Value
+	 *
+	 * @return bool
+	 */
+	abstract public function save($key, $data);
+
+	/**
+	 * Load data from the cache using a given key.
+	 *
+	 * @todo $offset is a horrible variable name because it creates confusion
+	 * with the ArrayAccess methods
+	 *
+	 * @param string $key    Name
+	 * @param int    $offset Offset
+	 * @param int    $limit  Limit
+	 *
+	 * @return mixed The stored data or false.
+	 */
+	abstract public function load($key, $offset = 0, $limit = null);
+
+	/**
+	 * Invalidate a key
+	 *
+	 * @param string $key Name
+	 *
+	 * @return bool
+	 */
+	abstract public function delete($key);
+
+	/**
+	 * Clear out all the contents of the cache.
+	 *
+	 * @return bool
+	 */
+	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  Name
+	 * @param string $data Value
+	 *
+	 * @return bool
+	 */
+	public function add($key, $data) {
+		if (!isset($this[$key])) {
+			return $this->save($key, $data);
+		}
+
+		return false;
+	}
+
+	// ARRAY ACCESS INTERFACE //////////////////////////////////////////////////////////
+
+	/**
+	 * Assigns a value for the specified key
+	 *
+	 * @see ArrayAccess::offsetSet()
+	 *
+	 * @param mixed $key   The key (offset) to assign the value to.
+	 * @param mixed $value The value to set.
+	 *
+	 * @return void
+	 */
+	function offsetSet($key, $value) {
+		$this->save($key, $value);
+	}
+
+	/**
+	 * Get the value for specified key
+	 *
+	 * @see ArrayAccess::offsetGet()
+	 *
+	 * @param mixed $key The key (offset) to retrieve.
+	 *
+	 * @return mixed
+	 */
+	function offsetGet($key) {
+		return $this->load($key);
+	}
+
+	/**
+	 * Unsets a key.
+	 *
+	 * @see ArrayAccess::offsetUnset()
+	 *
+	 * @param mixed $key The key (offset) to unset.
+	 *
+	 * @return void
+	 */
+	function offsetUnset($key) {
+		if (isset($this->$key)) {
+			unset($this->$key);
+		}
+	}
+
+	/**
+	 * Does key exist
+	 *
+	 * @see ArrayAccess::offsetExists()
+	 *
+	 * @param mixed $key A key (offset) to check for.
+	 *
+	 * @return bool
+	 */
+	function offsetExists($key) {
+		return isset($this->$key);
+	}
+}