clue/redis-protocol

A streaming redis wire protocol parser and serializer implementation in PHP

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Language: PHP

v0.3.0 2014-01-26 23:49 UTC

README

A streaming redis protocol parser and serializer written in PHP

Introduction

This parser and serializer implementation allows you to parse redis protocol messages into native PHP values and vice-versa. This is usually needed by a redis client implementation which also handles the connection socket.

To re-iterate: This is not a redis client implementation. This is a protocol implementation that is usually used by a redis client implementation. If you're looking for an easy way to build your own client implementation, then this is for you. If you merely want to connect to a redis server and issue some commands, you're probably better off using one of the existing client implementations.

Quickstart example

use Clue\Redis\Protocol;

$factory = new Protocol\Factory();
$parser = $factory->createResponseParser();
$serializer = $factory->createSerializer();

$fp = fsockopen('tcp://localhost', 6379);
fwrite($fp, $serializer->getRequestMessage('SET', array('name', 'value')));
fwrite($fp, $serializer->getRequestMessage('GET', array('name')));

// the commands are pipelined, so this may parse multiple responses
$models = $parser->pushIncoming(fread($fp, 4096));

$reply1 = array_shift($models);
$reply2 = array_shift($models);

var_dump($reply1->getValueNative()); // string(2) "OK"
var_dump($reply2->getValueNative()); // string(5) "value"

Usage

Factory

The factory helps with instantiating the right parser and serializer. Eventually the best available implementation will be chosen depending on your installed extensions. You're also free to instantiate them directly, but this will lock you down on a given implementation (which could be okay depending on your use-case).

Parser

The library includes a streaming redis protocol parser. As such, it can safely parse redis protocol messages and work with an incomplete data stream. For this, each included parser implements a single method ParserInterface::pushIncoming($chunk).

  • The ResponseParser is what most redis client implementation would want to use in order to parse incoming response messages from a redis server instance.
  • The RequestParser can be used to test messages coming from a redis client or even to implement a redis server.
  • The MessageBuffer decorates either of the available parsers and merely offers some helper methods in order to work with single messages:
    • hasIncomingModel() to check if there's a complete message in the pipeline
    • popIncomingModel() to extract a complete message from the incoming queue.

Model

Each message (response as well as request) is represented by a model implementing the ModelInterface that has two methods:

  • getValueNative() returns the wrapped value.
  • getMessageSerialized($serializer) returns the serialized protocol messages that will be sent over the wire.

These models are very lightweight and add little overhead. They help keeping the code organized and also provide a means to distinguish a single line StatusReply from a binary-safe BulkReply.

The parser always returns models. Models can also be instantiated directly:

$model = new Model\IntegerReply(123);
var_dump($model->getValueNative()); // int(123)
var_dump($model->getMessageSerialized($serializer)); // string(6) ":123\r\n"

Serializer

The serializer is responsible for creating serialized messages and the corresponing message models to be sent across the wire.

$message = $serializer->getRequestMessage('ping');
var_dump($message); // string(14) "$1\r\n*4\r\nping\r\n"

$message = $serializer->getRequestMessage('set', array('key', 'value'));
var_dump($message); // string(33) "$3\r\n*3\r\nset\r\n*3\r\nkey\r\n*5\r\nvalue\r\n"

$model = $serializer->createRequestModel('get', array('key'));
var_dump($model->getCommand()); // string(3) "get"
var_dump($model->getArgs()); // array(1) { string(3) "key" }
var_dump($model->getValueNative()); // array(2) { string(3) "GET", string(3) "key" }

$model = $serializer->createReplyModel(array('mixed', 12, array('value')));
assert($model implement Model\MultiBulkReply);

Install

It's very unlikely you'll want to use this protocol parser standalone. It should be added as a dependency to your redis client implementation by adding it to your composer.json:

{
    "require": {
        "clue/redis-protocol": "0.3.*"
    }
}

License

Its parser and serializer originally used to be based on jpd/redisent, which is released under the ISC license, copyright (c) 2009-2012 Justin Poliey justin@getglue.com.

Other than that, this library is MIT licensed.