Adds transaction support

Author: Lisio

src/Command.php

@@ -12,6 +12,7 @@
 use MongoDB\Driver\Exception\RuntimeException;
 use MongoDB\Driver\ReadConcern;
 use MongoDB\Driver\ReadPreference;
+use MongoDB\Driver\Session as DriverSession;
 use MongoDB\Driver\WriteConcern;
 use MongoDB\Driver\WriteResult;
 use Yii;
@@ -85,7 +86,10 @@ class Command extends BaseObject
      * @var ReadConcern|string read concern to be used by this command
      */
     private $_readConcern;
-
+    /**
+     * @var DriverSession session to be used by this command
+     */
+    private $_session;
 
     /**
      * Returns read preference for this command.
@@ -167,6 +171,17 @@ public function setReadConcern($readConcern)
         return $this;
     }
 
+    /**
+     * Sets session for this command.
+     * @param DriverSession $session session
+     * @return $this self reference
+     */
+    public function setSession($session)
+    {
+        $this->_session = $session;
+        return $this;
+    }
+
     /**
      * Executes this command.
      * @return \MongoDB\Driver\Cursor result cursor.
@@ -183,7 +198,11 @@ public function execute()
 
             $this->db->open();
             $mongoCommand = new \MongoDB\Driver\Command($this->document);
-            $cursor = $this->db->manager->executeCommand($databaseName, $mongoCommand, $this->getReadPreference());
+            $options = array_filter([
+                'readPreference' => $this->getReadPreference(),
+                'session' => $this->_session,
+            ]);
+            $cursor = $this->db->manager->executeCommand($databaseName, $mongoCommand, $options);
             $cursor->setTypeMap($this->db->typeMap);
 
             $this->endProfile($token, __METHOD__);
@@ -236,7 +255,11 @@ public function executeBatch($collectionName, $options = [])
             }
 
             $this->db->open();
-            $writeResult = $this->db->manager->executeBulkWrite($databaseName . '.' . $collectionName, $batch, $this->getWriteConcern());
+            $options = array_filter([
+                'writeConcern' => $this->getWriteConcern(),
+                'session' => $this->_session,
+            ]);
+            $writeResult = $this->db->manager->executeBulkWrite($databaseName . '.' . $collectionName, $batch, $options);
 
             $this->endProfile($token, __METHOD__);
         } catch (RuntimeException $e) {
@@ -283,7 +306,11 @@ public function query($collectionName, $options = [])
 
             $query = new \MongoDB\Driver\Query($this->document, $options);
             $this->db->open();
-            $cursor = $this->db->manager->executeQuery($databaseName . '.' . $collectionName, $query, $this->getReadPreference());
+            $options = array_filter([
+                'readPreference' => $this->getReadPreference(),
+                'session' => $this->_session,
+            ]);
+            $cursor = $this->db->manager->executeQuery($databaseName . '.' . $collectionName, $query, $options);
             $cursor->setTypeMap($this->db->typeMap);
 
             $this->endProfile($token, __METHOD__);

src/Connection.php

@@ -181,6 +181,10 @@ class Connection extends Component
      */
     private $_fileStreamWrapperRegistered = false;
 
+    /**
+     * @var \MongoDB\Driver\Session session
+     */
+    private $_session;
 
     /**
      * Sets default database name.
@@ -408,11 +412,17 @@ protected function initConnection()
      */
     public function createCommand($document = [], $databaseName = null)
     {
-        return new Command([
+        $command = new Command([
             'db' => $this,
             'databaseName' => $databaseName,
             'document' => $document,
         ]);
+
+        if ($this->_session) {
+            $command->setSession($this->_session);
+        }
+
+        return $command;
     }
 
     /**
@@ -432,4 +442,33 @@ public function registerFileStreamWrapper($force = false)
 
         return $this->fileStreamProtocol;
     }
+
+    /**
+     * @see Session::startTransaction()
+     */
+    public function startTransaction($options = [])
+    {
+        $this->_session = $this->manager->startSession();
+        $this->_session->startTransaction($options);
+    }
+
+    /**
+     * @see Session::abortTransaction()
+     */
+    public function abortTransaction()
+    {
+        $this->_session->abortTransaction();
+        $this->_session->endSession();
+        $this->_session = null;
+    }
+
+    /**
+     * @see Session::commitTransaction()
+     */
+    public function commitTransaction()
+    {
+        $this->_session->commitTransaction();
+        $this->_session->endSession();
+        $this->_session = null;
+    }
 }