updating session with delete and end

docs/Session.markdown

@@ -29,12 +29,24 @@ To specify which session driver to use you should pass the appropriate value to
 
 ### Available methods
 
-The available methods are `get`, `set` and `end`.
+The available methods are `get`, `set` `delete` and `end`.
+
+Get the value of a key $name:
 
     get($name);
+
+Set the key $name to $value:
+
     set($name, $value);
+
+Delete the key $name:
+
     delete($name);
 
+Remove and destroy all session variables:
+
+    end();
+
 ----------------------------------------
 
 ### Requirement for using Memcached

src/EpiSession.php

@@ -48,14 +48,18 @@ interface EpiSessionInterface
 {
   public function get($key = null);
   public function set($key = null, $value = null);
+  public function delete($key = null);
+  public function end();
 }
 
 if(!function_exists('getSession'))
 {
   function getSession()
   {
     $employ = EpiSession::employ();
-    $class = array_shift($employ);
+    $class = "";
+    if($employ)
+      $class = array_shift($employ);
     if($employ && class_exists($class))
       return EpiSession::getInstance($class, $employ);
     elseif(class_exists(EpiSession::PHP))

src/EpiSession_Apc.php

@@ -4,6 +4,15 @@ class EpiSession_Apc implements EpiSessionInterface
   private $key  = null;
   private $store= null;
 
+  public function delete($key = null)
+  {
+    if($this->get($key) === false)
+      return false;
+
+    unset($this->store[$key]);
+    return apc_store($this->key, $this->store);
+  }
+
   public function end()
   {
     apc_delete($this->key);

src/EpiSession_Memcached.php

@@ -19,6 +19,15 @@ public function __construct($params = array())
     $this->expiry   = !empty($params[3]) ? $params[3] : 3600;
   }
 
+  public function delete($key = null)
+  {
+    if ($this->get($key) === false)
+      return false;
+
+    unset($this->store[$key]);
+    return $this->memcached->set($this->key, $this->store);
+  }
+
   public function end()
   {
     if(!$this->connect())

src/EpiSession_Php.php

@@ -1,6 +1,15 @@
 <?php
 class EpiSession_Php implements EpiSessionInterface
 {
+  public function delete($key = null) 
+  {
+    if ($this->get($key) === false)
+      return false;
+
+    unset($_SESSION[$key]);
+    return true;
+  }
+
   public function end()
   {
     $_SESSION = array();