8 files changed, 194 insertions, 12 deletions
diff --git a/engine/classes/ElggBatch.php b/engine/classes/ElggBatch.php
index 5d59425d0..1912f89a2 100644
--- a/engine/classes/ElggBatch.php
+++ b/engine/classes/ElggBatch.php
@@ -229,8 +229,9 @@ class ElggBatch
 	private function getNextResultsChunk() {
 		// reset memory caches after first chunk load
 		if ($this->chunkIndex > 0) {
-			global $DB_QUERY_CACHE, $ENTITY_CACHE;
-			$DB_QUERY_CACHE = $ENTITY_CACHE = array();
+			global $ENTITY_CACHE;
+			$ENTITY_CACHE = array();
+			_elgg_invalidate_query_cache();
 		}
 
 		// always reset results.
diff --git a/engine/classes/ElggEntity.php b/engine/classes/ElggEntity.php
index 5a63c7b15..8b3ceb551 100644
--- a/engine/classes/ElggEntity.php
+++ b/engine/classes/ElggEntity.php
@@ -1270,7 +1270,7 @@ abstract class ElggEntity extends ElggData implements
 	public function save() {
 		$guid = $this->getGUID();
 		if ($guid > 0) {
-			cache_entity($this);
+			_elgg_cache_entity($this);
 
 			return update_entity(
 				$guid,
@@ -1320,7 +1320,7 @@ abstract class ElggEntity extends ElggData implements
 			$this->attributes['subtype'] = get_subtype_id($this->attributes['type'],
 				$this->attributes['subtype']);
 
-			cache_entity($this);
+			_elgg_cache_entity($this);
 
 			return $this->attributes['guid'];
 		}
@@ -1362,7 +1362,7 @@ abstract class ElggEntity extends ElggData implements
 
 			// Cache object handle
 			if ($this->attributes['guid']) {
-				cache_entity($this);
+				_elgg_cache_entity($this);
 			}
 
 			return true;
diff --git a/engine/classes/ElggGroup.php b/engine/classes/ElggGroup.php
index 7ab0bfa48..61f9163d5 100644
--- a/engine/classes/ElggGroup.php
+++ b/engine/classes/ElggGroup.php
@@ -335,7 +335,7 @@ class ElggGroup extends ElggEntity
 
 		$this->attributes = $attrs;
 		$this->attributes['tables_loaded'] = 2;
-		cache_entity($this);
+		_elgg_cache_entity($this);
 
 		return true;
 	}
diff --git a/engine/classes/ElggLRUCache.php b/engine/classes/ElggLRUCache.php
new file mode 100644
index 000000000..f51af2ed7
--- /dev/null
+++ b/engine/classes/ElggLRUCache.php
@@ -0,0 +1,181 @@
+<?php
+
+/**
+ * Least Recently Used Cache
+ *
+ * A fixed sized cache that removes the element used last when it reaches its
+ * size limit.
+ * 
+ * Based on https://github.com/cash/LRUCache
+ * 
+ * @access private
+ * 
+ * @package    Elgg.Core
+ * @subpackage Cache
+ */
+class ElggLRUCache implements ArrayAccess {
+	/** @var int */
+	protected $maximumSize;
+
+	/**
+	 * The front of the array contains the LRU element
+	 *
+	 * @var array
+	 */
+	protected $data = array();
+
+	/**
+	 * Create a LRU Cache
+	 *
+	 * @param int $size The size of the cache
+	 * @throws InvalidArgumentException
+	 */
+	public function __construct($size) {
+		if (!is_int($size) || $size <= 0) {
+			throw new InvalidArgumentException();
+		}
+		$this->maximumSize = $size;
+	}
+
+	/**
+	 * Get the value cached with this key
+	 *
+	 * @param int|string $key     The key. Strings that are ints are cast to ints.
+	 * @param mixed      $default The value to be returned if key not found. (Optional)
+	 * @return mixed
+	 */
+	public function get($key, $default = null) {
+		if (isset($this->data[$key])) {
+			$this->recordAccess($key);
+			return $this->data[$key];
+		} else {
+			return $default;
+		}
+	}
+
+	/**
+	 * Add something to the cache
+	 *
+	 * @param int|string $key   The key. Strings that are ints are cast to ints.
+	 * @param mixed      $value The value to cache
+	 * @return void
+	 */
+	public function set($key, $value) {
+		if (isset($this->data[$key])) {
+			$this->data[$key] = $value;
+			$this->recordAccess($key);
+		} else {
+			$this->data[$key] = $value;
+			if ($this->size() > $this->maximumSize) {
+				// remove least recently used element (front of array)
+				reset($this->data);
+				unset($this->data[key($this->data)]);
+			}
+		}
+	}
+
+	/**
+	 * Get the number of elements in the cache
+	 *
+	 * @return int
+	 */
+	public function size() {
+		return count($this->data);
+	}
+
+	/**
+	 * Does the cache contain an element with this key
+	 *
+	 * @param int|string $key The key
+	 * @return boolean
+	 */
+	public function containsKey($key) {
+		return isset($this->data[$key]);
+	}
+
+	/**
+	 * Remove the element with this key.
+	 *
+	 * @param int|string $key The key
+	 * @return mixed Value or null if not set
+	 */
+	public function remove($key) {
+		if (isset($this->data[$key])) {
+			$value = $this->data[$key];
+			unset($this->data[$key]);
+			return $value;
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Clear the cache
+	 * 
+	 * @return void
+	 */
+	public function clear() {
+		$this->data = array();
+	}
+
+	/**
+	 * Moves the element from current position to end of array
+	 * 
+	 * @param int|string $key The key
+	 * @return void
+	 */
+	protected function recordAccess($key) {
+		$value = $this->data[$key];
+		unset($this->data[$key]);
+		$this->data[$key] = $value;
+	}
+
+	/**
+	 * Assigns a value for the specified key
+	 *
+	 * @see ArrayAccess::offsetSet()
+	 *
+	 * @param int|string $key   The key to assign the value to.
+	 * @param mixed      $value The value to set.
+	 * @return void
+	 */
+	public function offsetSet($key, $value) {
+		$this->set($key, $value);
+	}
+
+	/**
+	 * Get the value for specified key
+	 *
+	 * @see ArrayAccess::offsetGet()
+	 *
+	 * @param int|string $key The key to retrieve.
+	 * @return mixed
+	 */
+	public function offsetGet($key) {
+		return $this->get($key);
+	}
+
+	/**
+	 * Unsets a key.
+	 *
+	 * @see ArrayAccess::offsetUnset()
+	 *
+	 * @param int|string $key The key to unset.
+	 * @return void
+	 */
+	public function offsetUnset($key) {
+		$this->remove($key);
+	}
+
+	/**
+	 * Does key exist?
+	 *
+	 * @see ArrayAccess::offsetExists()
+	 *
+	 * @param int|string $key A key to check for.
+	 * @return boolean
+	 */
+	public function offsetExists($key) {
+		return $this->containsKey($key);
+	}
+}
diff --git a/engine/classes/ElggObject.php b/engine/classes/ElggObject.php
index 3cb76ffaf..d54752dca 100644
--- a/engine/classes/ElggObject.php
+++ b/engine/classes/ElggObject.php
@@ -107,7 +107,7 @@ class ElggObject extends ElggEntity {
 
 		$this->attributes = $attrs;
 		$this->attributes['tables_loaded'] = 2;
-		cache_entity($this);
+		_elgg_cache_entity($this);
 
 		return true;
 	}
diff --git a/engine/classes/ElggSite.php b/engine/classes/ElggSite.php
index deba5087e..dd996fe98 100644
--- a/engine/classes/ElggSite.php
+++ b/engine/classes/ElggSite.php
@@ -124,7 +124,7 @@ class ElggSite extends ElggEntity {
 
 		$this->attributes = $attrs;
 		$this->attributes['tables_loaded'] = 2;
-		cache_entity($this);
+		_elgg_cache_entity($this);
 
 		return true;
 	}
diff --git a/engine/classes/ElggStaticVariableCache.php b/engine/classes/ElggStaticVariableCache.php
index 17d849400..9c14fdfba 100644
--- a/engine/classes/ElggStaticVariableCache.php
+++ b/engine/classes/ElggStaticVariableCache.php
@@ -11,7 +11,7 @@ class ElggStaticVariableCache extends ElggSharedMemoryCache {
 	/**
 	 * The cache.
 	 *
-	 * @var unknown_type
+	 * @var array
 	 */
 	private static $__cache;
 
@@ -22,7 +22,7 @@ class ElggStaticVariableCache extends ElggSharedMemoryCache {
 	 * memory, optionally with a given namespace (to avoid overlap).
 	 *
 	 * @param string $namespace The namespace for this cache to write to.
-	 * @note namespaces of the same name are shared!
+	 * @warning namespaces of the same name are shared!
 	 */
 	function __construct($namespace = 'default') {
 		$this->setNamespace($namespace);
@@ -80,7 +80,7 @@ class ElggStaticVariableCache extends ElggSharedMemoryCache {
 	}
 
 	/**
-	 * This was probably meant to delete everything?
+	 * Clears the cache for a particular namespace
 	 *
 	 * @return void
 	 */
diff --git a/engine/classes/ElggUser.php b/engine/classes/ElggUser.php
index b80065b27..6d9f10b57 100644
--- a/engine/classes/ElggUser.php
+++ b/engine/classes/ElggUser.php
@@ -112,7 +112,7 @@ class ElggUser extends ElggEntity
 
 		$this->attributes = $attrs;
 		$this->attributes['tables_loaded'] = 2;
-		cache_entity($this);
+		_elgg_cache_entity($this);
 
 		return true;
 	}