implementing key/value store of Persistance in Database storage

lib/Data/AbstractData.php

@@ -28,6 +28,15 @@ abstract class AbstractData
      */
     protected static $_instance = null;
 
+    /**
+     * cache for the traffic limiter
+     *
+     * @access private
+     * @static
+     * @var    array
+     */
+    protected static $_traffic_limiter_cache = array();
+
     /**
      * Enforce singleton, disable constructor
      *
@@ -138,7 +147,16 @@ abstract class AbstractData
      * @param  int $time
      * @return void
      */
-    abstract public function purgeValues($namespace, $time);
+    public function purgeValues($namespace, $time)
+    {
+        if ($namespace === 'traffic_limiter') {
+            foreach (self::$_traffic_limiter_cache as $key => $last_access) {
+                if ($last_access <= $time) {
+                    unset(self::$_traffic_limiter_cache[$key]);
+                }
+            }
+        }
+    }
 
     /**
      * Save a value.

lib/Data/Database.php

@@ -423,23 +423,6 @@ class Database extends AbstractData
         );
     }
 
-    /**
-     * Purge outdated entries.
-     *
-     * @access public
-     * @param  string $namespace
-     * @param  int $time
-     * @return void
-     */
-    public function purgeValues($namespace, $time)
-    {
-        switch ($namespace) {
-            case 'traffic_limiter':
-                ;
-                break;
-        }
-    }
-
     /**
      * Save a value.
      *
@@ -451,20 +434,19 @@ class Database extends AbstractData
      */
     public function setValue($value, $namespace, $key = '')
     {
-        switch ($namespace) {
-            case 'purge_limiter':
-                ;
-                break;
-            case 'salt':
-                ;
-                break;
-            case 'traffic_limiter':
-                ;
-                break;
-            default:
+        if ($namespace === 'traffic_limiter') {
+            self::$_traffic_limiter_cache[$key] = $value;
+            try {
+                $value = Json::encode(self::$_traffic_limiter_cache);
+            } catch (Exception $e) {
                 return false;
-                break;
+            }
         }
+        return self::_exec(
+            'UPDATE ' . self::_sanitizeIdentifier('config') .
+            ' SET value = ? WHERE id = ?',
+            array($value, strtoupper($namespace))
+        );
     }
 
     /**
@@ -477,7 +459,36 @@ class Database extends AbstractData
      */
     public function getValue($namespace, $key = '')
     {
+        $configKey = strtoupper($namespace);
+        $value = $this->_getConfig($configKey);
+        if ($value === '') {
+            // initialize the row, so that setValue can rely on UPDATE queries
+            self::_exec(
+                'INSERT INTO ' . self::_sanitizeIdentifier('config') .
+                ' VALUES(?,?)',
+                array($configKey, '')
+            );
 
+            // migrate filesystem based salt into database
+            $file = 'data' . DIRECTORY_SEPARATOR . 'salt.php';
+            if ($namespace === 'salt' && is_readable($file)) {
+                $value = Filesystem::getInstance(array('dir' => 'data'))->getValue('salt');
+                $this->setValue($value, 'salt');
+                @unlink($file);
+                return $value;
+            }
+        }
+        if ($value && $namespace === 'traffic_limiter') {
+            try {
+                self::$_traffic_limiter_cache = Json::decode($value);
+            } catch (Exception $e) {
+                self::$_traffic_limiter_cache = array();
+            }
+            if (array_key_exists($key, self::$_traffic_limiter_cache)) {
+                return self::$_traffic_limiter_cache[$key];
+            }
+        }
+        return (string) $value;
     }
 
     /**
@@ -629,7 +640,7 @@ class Database extends AbstractData
             'SELECT value FROM ' . self::_sanitizeIdentifier('config') .
             ' WHERE id = ?', array($key), true
         );
-        return $row['value'];
+        return $row ? $row['value']: '';
     }
 
     /**

lib/Data/Filesystem.php

@@ -38,15 +38,6 @@ class Filesystem extends AbstractData
      */
     private static $_path = 'data';
 
-    /**
-     * cache for the traffic limiter
-     *
-     * @access private
-     * @static
-     * @var    array
-     */
-    private static $_traffic_limiter_cache = array();
-
     /**
      * get instance of singleton
      *
@@ -249,27 +240,6 @@ class Filesystem extends AbstractData
         );
     }
 
-    /**
-     * Purge outdated entries.
-     *
-     * @access public
-     * @param  string $namespace
-     * @param  int $time
-     * @return void
-     */
-    public function purgeValues($namespace, $time)
-    {
-        switch ($namespace) {
-            case 'traffic_limiter':
-                foreach (self::$_traffic_limiter_cache as $key => $last_access) {
-                    if ($last_access <= $time) {
-                        unset(self::$_traffic_limiter_cache[$key]);
-                    }
-                }
-                break;
-        }
-    }
-
     /**
      * Save a value.
      *

lib/Data/GoogleCloudStorage.php

@@ -227,10 +227,11 @@ class GoogleCloudStorage extends AbstractData
      */
     public function purgeValues($namespace, $time)
     {
-        switch ($namespace) {
-            case 'traffic_limiter':
-                ;
-                break;
+        if ($namespace === 'traffic_limiter') {
+            // TODO implement purging of keys in namespace that are <= $time
+            // if GCS has no easy way to iterate all keys, consider using the
+            // self::$_traffic_limiter_cache in a similar way as the other
+            // implementations.
         }
     }