Initial commit of Session/Authentication code

Plugin architecture with single Database-backed implementation.

source/lib/SihnonFramework/Session.class.php

@@ -0,0 +1,61 @@
+<?php 
+
+class SihnonFramework_Session {
+    
+    protected $config;
+    
+    protected $state;
+    protected $dirty;
+    
+    public function __construct(Sihnon_Config $config) {
+        $this->config = $config;
+        $this->dirty = false;
+        
+        $this->init();
+    }
+    
+    public function __destruct() {
+        $this->teardown();
+    }
+    
+    protected function init() {
+        session_start();
+        $this->state = $_SESSION;
+    }
+    
+    protected function teardown() {
+        if ($this->dirty) {
+            $_SESSION = $this->state;
+            session_write_close();
+        }
+    }
+    
+    public function set($name, $value) {
+        $this->state[$name] = $value;
+        $this->dirty = true;
+    }
+    
+    public function get($name, $value, $default = null) {
+        if ( ! $this->exists($name)) {
+            return $default;
+        }
+        
+        return $this->state[$name];
+    }
+    
+    public function exists($name) {
+        return isset($this->state[$name]);
+    }
+    
+    public function delete($name) {
+        unset($this->state[$name]);
+        $this->dirty = true;
+    }
+    
+    public function securityLeveLChanged() {
+        session_regenerate_id(true);
+    }
+    
+}
+
+?>