2 files changed, 67 insertions, 0 deletions
diff --git a/includes/database/database.inc b/includes/database/database.inc
index 94517f002..8d6abb844 100644
--- a/includes/database/database.inc
+++ b/includes/database/database.inc
@@ -194,6 +194,17 @@ abstract class DatabaseConnection extends PDO {
   protected $target = NULL;
 
   /**
+   * The key representing this connection.
+   * 
+   * The key is a unique string which identifies a database connection. A
+   * connection can be a single server or a cluster of master and slaves (use
+   * target to pick between master and slave).
+   *
+   * @var string
+   */
+  protected $key = NULL;
+
+  /**
    * The current database logging object for this connection.
    *
    * @var DatabaseLog
@@ -470,6 +481,28 @@ abstract class DatabaseConnection extends PDO {
   }
 
   /**
+   * Tells this connection object what its key is.
+   *
+   * @param $target
+   *   The key this connection is for.
+   */
+  public function setKey($key) {
+    if (!isset($this->key)) {
+      $this->key = $key;
+    }
+  }
+
+  /**
+   * Returns the key this connection is associated with.
+   *
+   * @return
+   *   The key of this connection.
+   */
+  public function getKey() {
+    return $this->key;
+  }
+
+  /**
    * Associates a logging object with this connection.
    *
    * @param $logger
@@ -1539,6 +1572,7 @@ abstract class Database {
     require_once DRUPAL_ROOT . '/includes/database/' . $driver . '/database.inc';
     $new_connection = new $driver_class(self::$databaseInfo[$key][$target]);
     $new_connection->setTarget($target);
+    $new_connection->setKey($key);
 
     // If we have any active logging objects for this connection key, we need
     // to associate them with the connection we just opened.
diff --git a/includes/database/query.inc b/includes/database/query.inc
index d7e688eb5..7c590c220 100644
--- a/includes/database/query.inc
+++ b/includes/database/query.inc
@@ -242,6 +242,20 @@ abstract class Query implements QueryPlaceholderInterface {
   protected $connection;
 
   /**
+   * The target of the connection object.
+   * 
+   * @var string
+   */
+  protected $connectionTarget;
+
+  /**
+   * The key of the connection object.
+   * 
+   * @var string
+   */
+  protected $connectionKey;
+
+  /**
    * The query options to pass on to the connection object.
    *
    * @var array
@@ -270,10 +284,29 @@ abstract class Query implements QueryPlaceholderInterface {
    */
   public function __construct(DatabaseConnection $connection, $options) {
     $this->connection = $connection;
+    $this->connectionKey = $this->connection->getKey();
+    $this->connectionTarget = $this->connection->getTarget();
+
     $this->queryOptions = $options;
   }
 
   /**
+   * Implements the magic __sleep function to disconnect from the database.
+   */
+  public function __sleep() {
+    $keys = get_object_vars($this);
+    unset($keys['connection']);
+    return array_keys($keys);
+  }
+
+  /**
+  * Implements the magic __wakeup function to reconnect to the database.
+   */
+  public function __wakeup() {
+    $this->connection = Database::getConnection($this->connectionTarget, $this->connectionKey);
+  }
+
+  /**
    * Runs the query against the database.
    */
   abstract protected function execute();