Retwis ported to modern Redis data types.

The example (and related documentation at redis.io) was not updated for
5 years. Redis had no sorted sets and hashes when the original code was
written (!). An update was really needed.

We also use a modern PHP client now: Predis. A copy is shipped within
this repository to make life easier to newcomers trying Redis for the
first time via this example.

Predis/Protocol/Text/ComposableTextProtocol.php

@@ -0,0 +1,129 @@
+<?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\Protocol\Text;
+
+use Predis\Command\CommandInterface;
+use Predis\Connection\ComposableConnectionInterface;
+use Predis\Protocol\ResponseReaderInterface;
+use Predis\Protocol\CommandSerializerInterface;
+use Predis\Protocol\ComposableProtocolInterface;
+
+/**
+ * Implements a customizable protocol processor that uses the standard Redis
+ * wire protocol to serialize Redis commands and parse replies returned by
+ * the server using a pluggable set of classes.
+ *
+ * @link http://redis.io/topics/protocol
+ * @author Daniele Alessandri <suppakilla@gmail.com>
+ */
+class ComposableTextProtocol implements ComposableProtocolInterface
+{
+    private $serializer;
+    private $reader;
+
+    /**
+     * @param array $options Set of options used to initialize the protocol processor.
+     */
+    public function __construct(Array $options = array())
+    {
+        $this->setSerializer(new TextCommandSerializer());
+        $this->setReader(new TextResponseReader());
+
+        if (count($options) > 0) {
+            $this->initializeOptions($options);
+        }
+    }
+
+    /**
+     * Initializes the protocol processor using a set of options.
+     *
+     * @param array $options Set of options.
+     */
+    private function initializeOptions(Array $options)
+    {
+        foreach ($options as $k => $v) {
+            $this->setOption($k, $v);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setOption($option, $value)
+    {
+        switch ($option) {
+            case 'iterable_multibulk':
+                $handler = $value ? new ResponseMultiBulkStreamHandler() : new ResponseMultiBulkHandler();
+                $this->reader->setHandler(TextProtocol::PREFIX_MULTI_BULK, $handler);
+                break;
+
+            default:
+                throw new \InvalidArgumentException("The option $option is not supported by the current protocol");
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function serialize(CommandInterface $command)
+    {
+        return $this->serializer->serialize($command);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function write(ComposableConnectionInterface $connection, CommandInterface $command)
+    {
+        $connection->writeBytes($this->serializer->serialize($command));
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function read(ComposableConnectionInterface $connection)
+    {
+        return $this->reader->read($connection);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setSerializer(CommandSerializerInterface $serializer)
+    {
+        $this->serializer = $serializer;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getSerializer()
+    {
+        return $this->serializer;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setReader(ResponseReaderInterface $reader)
+    {
+        $this->reader = $reader;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getReader()
+    {
+        return $this->reader;
+    }
+}