Implement cache key prefixing (as suggested in #1197) and update the Cache docs

1 files changed, 32 insertions, 26 deletions

diff --git a/system/libraries/Cache/Cache.php b/system/libraries/Cache/Cache.php
index 4395cf411..ce71445df 100644
--- a/system/libraries/Cache/Cache.php
+++ b/system/libraries/Cache/Cache.php
@@ -41,7 +41,7 @@ class CI_Cache extends CI_Driver_Library {
 	 *
 	 * @var array
 	 */
-	protected $valid_drivers 	= array(
+	protected $valid_drivers = array(
 		'cache_apc',
 		'cache_dummy',
 		'cache_file',
@@ -67,16 +67,23 @@ class CI_Cache extends CI_Driver_Library {
 	/**
 	 * Fallback driver
 	 *
-	 * @param string
+	 * @var string
 	 */
 	protected $_backup_driver = 'dummy';
 
 	/**
+	 * Cache key prefix
+	 *
+	 * @var	string
+	 */
+	public $key_prefix = '';
+
+	/**
 	 * Constructor
 	 *
 	 * Initialize class properties based on the configuration array.
 	 *
-	 * @param	array
+	 * @param	array	$config = array()
 	 * @return	void
 	 */
 	public function __construct($config = array())
@@ -96,12 +103,11 @@ class CI_Cache extends CI_Driver_Library {
 			}
 		}
 
-		if (isset($config['backup']))
+		isset($config['key_prefix']) AND $this->key_prefix = $config['key_prefix'];
+
+		if (isset($config['backup']) && in_array('cache_'.$config['backup'], $this->valid_drivers))
 		{
-			if (in_array('cache_'.$config['backup'], $this->valid_drivers))
-			{
-				$this->_backup_driver = $config['backup'];
-			}
+			$this->_backup_driver = $config['backup'];
 		}
 
 		// If the specified adapter isn't available, check the backup.
@@ -129,12 +135,12 @@ class CI_Cache extends CI_Driver_Library {
 	 * Look for a value in the cache. If it exists, return the data
 	 * if not, return FALSE
 	 *
-	 * @param	string
-	 * @return	mixed	value that is stored/FALSE on failure
+	 * @param	string	$id
+	 * @return	mixed	value matching $id or FALSE on failure
 	 */
 	public function get($id)
 	{
-		return $this->{$this->_adapter}->get($id);
+		return $this->{$this->_adapter}->get($this->key_prefix.$id);
 	}
 
 	// ------------------------------------------------------------------------
@@ -142,14 +148,14 @@ class CI_Cache extends CI_Driver_Library {
 	/**
 	 * Cache Save
 	 *
-	 * @param	string	Unique Key
-	 * @param	mixed	Data to store
-	 * @param	int	Length of time (in seconds) to cache the data
-	 * @return	bool	true on success/false on failure
+	 * @param	string	$id		Cache ID
+	 * @param	mixed	$data		Data to store
+	 * @param	int	$ttl = 60	Cache TTL (in seconds)
+	 * @return	bool	TRUE on success, FALSE on failure
 	 */
 	public function save($id, $data, $ttl = 60)
 	{
-		return $this->{$this->_adapter}->save($id, $data, $ttl);
+		return $this->{$this->_adapter}->save($this->key_prefix.$id, $data, $ttl);
 	}
 
 	// ------------------------------------------------------------------------
@@ -157,12 +163,12 @@ class CI_Cache extends CI_Driver_Library {
 	/**
 	 * Delete from Cache
 	 *
-	 * @param	mixed	unique identifier of the item in the cache
-	 * @return	bool	true on success/false on failure
+	 * @param	string	$id	Cache ID
+	 * @return	bool	TRUE on success, FALSE on failure
 	 */
 	public function delete($id)
 	{
-		return $this->{$this->_adapter}->delete($id);
+		return $this->{$this->_adapter}->delete($this->key_prefix.$id);
 	}
 
 	// ------------------------------------------------------------------------
@@ -170,7 +176,7 @@ class CI_Cache extends CI_Driver_Library {
 	/**
 	 * Clean the cache
 	 *
-	 * @return	bool	false on failure/true on success
+	 * @return	bool	TRUE on success, FALSE on failure
 	 */
 	public function clean()
 	{
@@ -182,8 +188,8 @@ class CI_Cache extends CI_Driver_Library {
 	/**
 	 * Cache Info
 	 *
-	 * @param	string	user/filehits
-	 * @return	mixed	array on success, false on failure
+	 * @param	string	$type = 'user'	user/filehits
+	 * @return	mixed	array containing cache info on success OR FALSE on failure
 	 */
 	public function cache_info($type = 'user')
 	{
@@ -195,12 +201,12 @@ class CI_Cache extends CI_Driver_Library {
 	/**
 	 * Get Cache Metadata
 	 *
-	 * @param	mixed	key to get cache metadata on
-	 * @return	mixed	return value from child method
+	 * @param	string	$id	key to get cache metadata on
+	 * @return	mixed	cache item metadata
 	 */
 	public function get_metadata($id)
 	{
-		return $this->{$this->_adapter}->get_metadata($id);
+		return $this->{$this->_adapter}->get_metadata($this->key_prefix.$id);
 	}
 
 	// ------------------------------------------------------------------------
@@ -208,7 +214,7 @@ class CI_Cache extends CI_Driver_Library {
 	/**
 	 * Is the requested driver supported in this environment?
 	 *
-	 * @param	string	The driver to test.
+	 * @param	string	$driver	The driver to test
 	 * @return	array
 	 */
 	public function is_supported($driver)