Extract common PubSub handling logic into a separate abstract class.

lib/Predis/PubSub/AbstractPubSubContext.php

@@ -0,0 +1,212 @@
+<?php
+
+/*
+ * This file is part of the Predis package.
+ *
+ * (c) Daniele Alessandri <suppakilla@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Predis\PubSub;
+
+use Predis\ClientInterface;
+use Predis\Helpers;
+use Predis\ClientException;
+use Predis\NotSupportedException;
+
+/**
+ * Client-side abstraction of a Publish / Subscribe context.
+ *
+ * @author Daniele Alessandri <suppakilla@gmail.com>
+ */
+abstract class AbstractPubSubContext implements \Iterator
+{
+    const SUBSCRIBE    = 'subscribe';
+    const UNSUBSCRIBE  = 'unsubscribe';
+    const PSUBSCRIBE   = 'psubscribe';
+    const PUNSUBSCRIBE = 'punsubscribe';
+    const MESSAGE      = 'message';
+    const PMESSAGE     = 'pmessage';
+
+    const STATUS_VALID       = 1;	// 0b0001
+    const STATUS_SUBSCRIBED  = 2;	// 0b0010
+    const STATUS_PSUBSCRIBED = 4;	// 0b0100
+
+    private $position = null;
+    private $statusFlags = self::STATUS_VALID;
+
+    /**
+     * Automatically closes the context when PHP's garbage collector kicks in.
+     */
+    public function __destruct()
+    {
+        $this->closeContext(true);
+    }
+
+    /**
+     * Checks if the specified flag is valid in the state of the context.
+     *
+     * @param int $value Flag.
+     * @return Boolean
+     */
+    protected function isFlagSet($value)
+    {
+        return ($this->statusFlags & $value) === $value;
+    }
+
+    /**
+     * Subscribes to the specified channels.
+     *
+     * @param mixed $arg,... One or more channel names.
+     */
+    public function subscribe(/* arguments */)
+    {
+        $this->writeCommand(self::SUBSCRIBE, func_get_args());
+        $this->statusFlags |= self::STATUS_SUBSCRIBED;
+    }
+
+    /**
+     * Unsubscribes from the specified channels.
+     *
+     * @param mixed $arg,... One or more channel names.
+     */
+    public function unsubscribe(/* arguments */)
+    {
+        $this->writeCommand(self::UNSUBSCRIBE, func_get_args());
+    }
+
+    /**
+     * Subscribes to the specified channels using a pattern.
+     *
+     * @param mixed $arg,... One or more channel name patterns.
+     */
+    public function psubscribe(/* arguments */)
+    {
+        $this->writeCommand(self::PSUBSCRIBE, func_get_args());
+        $this->statusFlags |= self::STATUS_PSUBSCRIBED;
+    }
+
+    /**
+     * Unsubscribes from the specified channels using a pattern.
+     *
+     * @param mixed $arg,... One or more channel name patterns.
+     */
+    public function punsubscribe(/* arguments */)
+    {
+        $this->writeCommand(self::PUNSUBSCRIBE, func_get_args());
+    }
+
+    /**
+     * Closes the context by unsubscribing from all the subscribed channels.
+     * Optionally, the context can be forcefully closed by dropping the
+     * underlying connection.
+     *
+     * @param Boolean $force Forcefully close the context by closing the connection.
+     * @return Boolean Returns false if there are no pending messages.
+     */
+    public function closeContext($force = false)
+    {
+        if (!$this->valid()) {
+            return false;
+        }
+
+        if ($force) {
+            $this->invalidate();
+            $this->disconnect();
+        }
+        else {
+            if ($this->isFlagSet(self::STATUS_SUBSCRIBED)) {
+                $this->unsubscribe();
+            }
+            if ($this->isFlagSet(self::STATUS_PSUBSCRIBED)) {
+                $this->punsubscribe();
+            }
+        }
+
+        return !$force;
+    }
+
+    /**
+     * Closes the underlying connection on forced disconnection.
+     */
+    protected abstract function disconnect();
+
+    /**
+     * Writes a Redis command on the underlying connection.
+     *
+     * @param string $method ID of the command.
+     * @param array $arguments List of arguments.
+     */
+    protected abstract function writeCommand($method, $arguments);
+
+    /**
+     * {@inheritdoc}
+     */
+    public function rewind()
+    {
+        // NOOP
+    }
+
+    /**
+     * Returns the last message payload retrieved from the server and generated
+     * by one of the active subscriptions.
+     *
+     * @return array
+     */
+    public function current()
+    {
+        return $this->getValue();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function key()
+    {
+        return $this->position;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function next()
+    {
+        if ($this->valid()) {
+            $this->position++;
+        }
+
+        return $this->position;
+    }
+
+    /**
+     * Checks if the the context is still in a valid state to continue.
+     *
+     * @return Boolean
+     */
+    public function valid()
+    {
+        $isValid = $this->isFlagSet(self::STATUS_VALID);
+        $subscriptionFlags = self::STATUS_SUBSCRIBED | self::STATUS_PSUBSCRIBED;
+        $hasSubscriptions = ($this->statusFlags & $subscriptionFlags) > 0;
+
+        return $isValid && $hasSubscriptions;
+    }
+
+    /**
+     * Resets the state of the context.
+     */
+    protected function invalidate()
+    {
+        $this->statusFlags = 0;	// 0b0000;
+    }
+
+    /**
+     * Waits for a new message from the server generated by one of the active
+     * subscriptions and returns it when available.
+     *
+     * @return array
+     */
+    protected abstract function getValue();
+}

lib/Predis/PubSub/PubSubContext.php

@@ -21,21 +21,9 @@ use Predis\NotSupportedException;
  *
  * @author Daniele Alessandri <suppakilla@gmail.com>
  */
-class PubSubContext implements \Iterator
+class PubSubContext extends AbstractPubSubContext
 {
-    const SUBSCRIBE    = 'subscribe';
-    const UNSUBSCRIBE  = 'unsubscribe';
-    const PSUBSCRIBE   = 'psubscribe';
-    const PUNSUBSCRIBE = 'punsubscribe';
-    const MESSAGE      = 'message';
-    const PMESSAGE     = 'pmessage';
-
-    const STATUS_VALID       = 1;	// 0b0001
-    const STATUS_SUBSCRIBED  = 2;	// 0b0010
-    const STATUS_PSUBSCRIBED = 4;	// 0b0100
-
     private $client;
-    private $position;
     private $options;
 
     /**
@@ -47,20 +35,11 @@ class PubSubContext implements \Iterator
         $this->checkCapabilities($client);
         $this->options = $options ?: array();
         $this->client = $client;
-        $this->statusFlags = self::STATUS_VALID;
 
         $this->genericSubscribeInit('subscribe');
         $this->genericSubscribeInit('psubscribe');
     }
 
-    /**
-     * Automatically closes the context when PHP's garbage collector kicks in.
-     */
-    public function __destruct()
-    {
-        $this->closeContext(true);
-    }
-
     /**
      * Checks if the passed client instance satisfies the required conditions
      * needed to initialize a Publish / Subscribe context.
@@ -92,95 +71,9 @@ class PubSubContext implements \Iterator
     }
 
     /**
-     * Checks if the specified flag is valid in the state of the context.
-     *
-     * @param int $value Flag.
-     * @return Boolean
-     */
-    private function isFlagSet($value)
-    {
-        return ($this->statusFlags & $value) === $value;
-    }
-
-    /**
-     * Subscribes to the specified channels.
-     *
-     * @param mixed $arg,... One or more channel names.
-     */
-    public function subscribe(/* arguments */)
-    {
-        $this->writeCommand(self::SUBSCRIBE, func_get_args());
-        $this->statusFlags |= self::STATUS_SUBSCRIBED;
-    }
-
-    /**
-     * Unsubscribes from the specified channels.
-     *
-     * @param mixed $arg,... One or more channel names.
-     */
-    public function unsubscribe(/* arguments */)
-    {
-        $this->writeCommand(self::UNSUBSCRIBE, func_get_args());
-    }
-
-    /**
-     * Subscribes to the specified channels using a pattern.
-     *
-     * @param mixed $arg,... One or more channel name patterns.
-     */
-    public function psubscribe(/* arguments */)
-    {
-        $this->writeCommand(self::PSUBSCRIBE, func_get_args());
-        $this->statusFlags |= self::STATUS_PSUBSCRIBED;
-    }
-
-    /**
-     * Unsubscribes from the specified channels using a pattern.
-     *
-     * @param mixed $arg,... One or more channel name patterns.
-     */
-    public function punsubscribe(/* arguments */)
-    {
-        $this->writeCommand(self::PUNSUBSCRIBE, func_get_args());
-    }
-
-    /**
-     * Closes the context by unsubscribing from all the subscribed channels.
-     * Optionally, the context can be forcefully closed by dropping the
-     * underlying connection.
-     *
-     * @param Boolean $force Forcefully close the context by closing the connection.
-     * @return Boolean Returns false if there are no pending messages.
-     */
-    public function closeContext($force = false)
-    {
-        if (!$this->valid()) {
-            return false;
-        }
-
-        if ($force) {
-            $this->invalidate();
-            $this->client->disconnect();
-        }
-        else {
-            if ($this->isFlagSet(self::STATUS_SUBSCRIBED)) {
-                $this->unsubscribe();
-            }
-            if ($this->isFlagSet(self::STATUS_PSUBSCRIBED)) {
-                $this->punsubscribe();
-            }
-        }
-
-        return !$force;
-    }
-
-    /**
-     * Writes a Redis command on the underlying connection.
-     *
-     * @param string $method ID of the command.
-     * @param array $arguments List of arguments.
+     * {@inheritdoc}
      */
-    private function writeCommand($method, $arguments)
+    protected function writeCommand($method, $arguments)
     {
         $arguments = Helpers::filterArrayArguments($arguments);
         $command = $this->client->createCommand($method, $arguments);
@@ -190,71 +83,15 @@ class PubSubContext implements \Iterator
     /**
      * {@inheritdoc}
      */
-    public function rewind()
-    {
-        // NOOP
-    }
-
-    /**
-     * Returns the last message payload retrieved from the server and generated
-     * by one of the active subscriptions.
-     *
-     * @return array
-     */
-    public function current()
-    {
-        return $this->getValue();
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function key()
+    protected function disconnect()
     {
-        return $this->position;
+        $this->client->disconnect();
     }
 
     /**
      * {@inheritdoc}
      */
-    public function next()
-    {
-        if ($this->valid()) {
-            $this->position++;
-        }
-
-        return $this->position;
-    }
-
-    /**
-     * Checks if the the context is still in a valid state to continue.
-     *
-     * @return Boolean
-     */
-    public function valid()
-    {
-        $isValid = $this->isFlagSet(self::STATUS_VALID);
-        $subscriptionFlags = self::STATUS_SUBSCRIBED | self::STATUS_PSUBSCRIBED;
-        $hasSubscriptions = ($this->statusFlags & $subscriptionFlags) > 0;
-
-        return $isValid && $hasSubscriptions;
-    }
-
-    /**
-     * Resets the state of the context.
-     */
-    private function invalidate()
-    {
-        $this->statusFlags = 0;	// 0b0000;
-    }
-
-    /**
-     * Waits for a new message from the server generated by one of the active
-     * subscriptions and returns it when available.
-     *
-     * @return array
-     */
-    private function getValue()
+    protected function getValue()
     {
         $response = $this->client->getConnection()->read();