Add some supported options to Predis\Client::pipeline().

Only two options available for now, used to specify which kind of
pipeline object the client should use or return:

  - "atomic": returns a pipeline wrapped in a MULTI / EXEC transaction
    (class: Predis\Pipeline\Atomic).
  - "fire-and-forget": returns a pipeline that does not read back
    responses from the server (class: Predis\Pipeline\FireAndForget).

We might add more options in the future.

CHANGELOG.md

@@ -18,7 +18,13 @@ v0.9.0 (201x-xx-xx)
   even for custom options defined by the user.
 
 - Removed pipeline executors, now command pipelines can be easily customized by
-  extending the standard `Predis\Pipeline\Pipeline` class.
+  extending the standard `Predis\Pipeline\Pipeline` class. Accepted options when
+  creating a pipeline using `Predis\Client::pipeline()` are:
+
+    - `atomic`: returns a pipeline wrapped in a MULTI / EXEC transaction
+      (class: `Predis\Pipeline\Atomic`).
+    - `fire-and-forget`: returns a pipeline that does not read back responses
+      (class: `Predis\Pipeline\FireAndForget`).
 
 - Most classes and interfaces in the `Predis\Protocol` namespace have been moved
   or renamed while rationalizing the whole API of external protocol processors.

lib/Predis/Client.php

@@ -371,7 +371,15 @@ class Client implements ClientInterface
      */
     protected function createPipeline(array $options = null, $callable = null)
     {
-        $pipeline = new Pipeline\Pipeline($this);
+        if (isset($options['atomic']) && $options['atomic']) {
+            $class = 'Predis\Pipeline\Atomic';
+        } else if (isset($options['fire-and-forget']) && $options['fire-and-forget']) {
+            $class = 'Predis\Pipeline\FireAndForget';
+        } else {
+            $class = 'Predis\Pipeline\Pipeline';
+        }
+
+        $pipeline = new $class($this);
 
         if (isset($callable)) {
             return $pipeline->execute($callable);

tests/Predis/ClientTest.php

@@ -581,9 +581,10 @@ class ClientTest extends StandardTestCase
     public function testPipelineWithArrayReturnsPipeline()
     {
         $client = new Client();
-        $options = array();
 
-        $this->assertInstanceOf('Predis\Pipeline\Pipeline', $client->pipeline($options));
+        $this->assertInstanceOf('Predis\Pipeline\Pipeline', $client->pipeline(array()));
+        $this->assertInstanceOf('Predis\Pipeline\Atomic', $client->pipeline(array('atomic' => true)));
+        $this->assertInstanceOf('Predis\Pipeline\FireAndForget', $client->pipeline(array('fire-and-forget' => true)));
     }
 
     /**