clue/redis-protocol

A streaming Redis protocol (RESP) parser and serializer written in pure PHP.

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.

Table of contents

• Support us
• Quickstart example
• Usage
  • Factory
  • Parser
  • Model
  • Serializer
• Install
• Tests
• License

Support us

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Quickstart example

<?php

require __DIR__ . '/vendor/autoload.php';

$factory = new Clue\Redis\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"

See also the examples.

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 instead. The recommended way to install this library is through Composer. New to Composer?

This will install the latest supported version:

composer require clue/redis-protocol:^0.3.2

See also the CHANGELOG for details about version upgrades.

This project aims to run on any platform and thus does not require any PHP extensions and supports running on legacy PHP 5.3 through current PHP 8+. It's highly recommended to use the latest supported PHP version for this project.

Tests

To run the test suite, you first need to clone this repo and then install all dependencies through Composer:

composer install

To run the test suite, go to the project root and run:

vendor/bin/phpunit

The test suite is set up to always ensure 100% code coverage across all supported environments. If you have the Xdebug extension installed, you can also generate a code coverage report locally like this:

XDEBUG_MODE=coverage vendor/bin/phpunit --coverage-text

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 [email protected].

Other than that, this project is released under the permissive MIT license.

Did you know that I offer custom development services and issuing invoices for sponsorships of releases and for contributions? Contact me (@clue) for details.