zenstruck/redis

Lazy proxy for php-redis with DX helpers, utilities and a unified API.

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v0.1.0 2022-03-18 16:55 UTC

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Last update: 2024-01-31 00:35:57 UTC


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Lazy proxy for php-redis with DX helpers, utilities and a unified API.

Zenstruck\Redis is a unified proxy for \Redis|\RedisArray|\RedisCluster. With a few exceptions and considerations, the API is the same no matter the underlying client. This allows you to use the same API in development, where you are likely just using \Redis, and production, where you could be using \RedisArray or \RedisCluster.

The proxy is lazy in that, if created via a DSN, doesn't instantiate the underlying client until a command is executed.

This library integrates well with Symfony and a recipe is available.

Installation

composer require zenstruck/redis

Redis Factory

Creating a Redis client instance is done via a DSN string. The DSN must use the following format:

redis[s]://[pass@][ip|host|socket[:port]][/db-index][?{option}={value}...]

Redis Proxy Factory

It is recommended to use the proxy whenever possible. It has the following benefits over using the real client:

  1. Lazy: a connection is not established until a Redis command is actually called.
  2. Encapsulated: for the most part, knowledge of the real client is not required. You don't need to change your usage depending on the client used. There are some exceptions to this.
  3. Developer Experience (DX): use the fluent sequence and transaction api.

Here are some examples creating the proxy from a DSN.

use Zenstruck\Redis;

$proxy = Redis::create('redis://localhost'); // Zenstruck\Redis<\Redis>
$proxy = Redis::create('redis://localhost?redis_sentinel=sentinel_service'); // Zenstruck\Redis<\Redis> (using Redis Sentinel)
$proxy = Redis::create('redis:?host[host1]&host[host2]'); // Zenstruck\Redis<\RedisArray>
$proxy = Redis::create('redis:?host[host1]&host[host2]&redis_cluster=1'); // Zenstruck\Redis<\RedisCluster>

You can also create a Proxy from an exising instance of \Redis|\RedisArray|\RedisCluster:

use Zenstruck\Redis;

/** @var \Redis|\RedisArray|\RedisCluster $client */

$proxy = Redis::wrap($client)

Redis Real Client Factory

An instance of \Redis|\RedisArray|\RedisCluster can be created directly:

use Zenstruck\Redis;

$client = Redis::createClient('redis://localhost'); // \Redis
$client = Redis::createClient('redis://localhost?redis_sentinel=sentinel_service'); // \Redis (using Redis Sentinel)
$client = Redis::createClient('redis:?host[host1]&host[host2]'); // \RedisArray
$client = Redis::createClient('redis:?host[host1]&host[host2]&redis_cluster=1'); // \RedisCluster

Factory Options

Certain Redis options can be set via your DSN's query parameters or passed as an array to the second parameter of Zenstruck\Redis::create/createClient().

Prefix

You can set a prefix for all keys:

use Zenstruck\Redis;

$proxy = Redis::create('redis://localhost?prefix=app:');
$proxy = Redis::create('redis://localhost', ['prefix' => 'app:']); // equivalent to above

Serializer Option

By default, Redis stores all scalar/null values as strings and objects/arrays as "Array"/"Object". In order to store properly typed values and objects/arrays, you must configure a Redis serializer:

use Zenstruck\Redis;

// PHP: serialize/unserialize values
$proxy = Redis::create('redis://localhost?serializer=php');
$proxy = Redis::create('redis://localhost', ['serializer' => \Redis::SERIALIZER_PHP]); // equivalent to above

// JSON: json_encode/json_decode values (doesn't work for objects)
$proxy = Redis::create('redis://localhost?serializer=json');
$proxy = Redis::create('redis://localhost', ['serializer' => \Redis::SERIALIZER_JSON]); // equivalent to above

NOTE: There is a performance trade off when using Redis serialization. Consider creating a separate client for operations/logic that requires serialization.

Redis Proxy API

/** @var Zenstruck\Redis $proxy */

// call any \Redis|\RedisArray|\RedisCluster method
$proxy->set('mykey', 'value');
$proxy->get('mykey'); // "value"

// get the "real" client
$proxy->realClient(); // \Redis|\RedisArray|\RedisCluster

Sequences/Pipelines and Transactions

The proxy has a fluent, auto-completable API for Redis pipelines and transactions:

/** @var Zenstruck\Redis $proxy */

// use \Redis::multi()
$results = $proxy->transaction()
    ->set('x', '42')
    ->incr('x')
    ->get('x')->as('value') // alias the result of this command
    ->del('x')
    ->execute() // the results of the above transaction as an array (keyed by index of command or alias if set)
;

$results['value']; // "43" (result of ->get())
$results[3]; // true (result of ->del())

// use \Redis::pipeline() - see note below about \RedisCluster
$proxy->sequence()
    ->set('x', '42')
    ->incr('x')
    ->get('x')->as('value') // alias the result of this command
    ->del('x')
    ->execute() // the results of the above sequence as an array (keyed by index of command of alias if set)
;

$results['value']; // "43" (result of ->get())
$results[3]; // true (result of ->del())

NOTE: When using sequence() with \RedisCluster, the commands are executed atomically as pipelines are not supported.

NOTE: When using sequence()/transaction() with a \RedisArray instance, the first command in the sequence/transaction must be a "key-based command" (ie get()/set()). This is to choose the node the transaction is run on.

Countable\Iterable

Zenstruck\Redis is countable and iterable. There are some differences when counting/iterating depending on the underlying client:

  • \Redis: count is always 1 and iterates over itself once
  • \RedisArray: count is the number of hosts and iterates over each host wrapped in a proxy.
  • \RedisCluser: count is the number of masters and iterates over each master with node parameters pre-set. This enables running node commands on each master without passing node parameters to these commands (when iterating)
/** @var Zenstruck\Redis $proxy */

$proxy->count(); // 1 if \Redis, # hosts if \RedisArray, # "masters" if \RedisCluster

foreach ($proxy as $node) {
    $proxy->flushAll(); // this is permitted even for \RedisCluster (which typically requires a $nodeParams argument)
}

NOTE: If running commands that require being run on each host/master it is recommended to iterate and run even if using \Redis. This allows a seamless transition to \RedisArray/\RedisCluster later.

Utilities

ExpiringSet

Zenstruck\Redis\Utility\ExpiringSet encapsulates the concept of a Redis expiring set: a set (unordered list with no duplicates) whose members expire after a time. Each read/write operation on the set prunes expired members.

/** @var Zenstruck\Redis $client */

$set = $client->expiringSet('my-set'); // redis key to store the set

$set->add('member1', 600); // set add "member1" that expires in 10 minutes
$set->add('member1', new \DateInterval::createFromDateString('5 minutes')); // can use \DateInterval for the TTL
$set->add('member1', new \DateTime('+5 minutes')); // use \DateTimeInterface to set specific expiry timestamp

$set->remove('member1'); // explicitly remove a member

$set->all(); // array - all unexpired members

$set->contains('member'); // true/false

$set->clear(); // clear all items

$set->prune(); // explicitly "prune" the set (remove expired members)

count($set); // int - number of unexpired members

foreach ($set as $member) {
    // iterate over unexpired members
}

// fluent
$set
    ->add('member1', 600)
    ->add('member2', 600)
    ->remove('member1')
    ->remove('member2')
    ->prune()
    ->clear()
;

NOTE: In order to use complex types (arrays/objects) as members, your redis client must be configured with a serializer.

Below is a pseudocode example using this object for tracking active users on a website. When authenticated users login or request a page, their username is added to the set with a 5-minute idle time-to-live (TTL). A user is considered active within this time. On logout, they are removed from the set. If a user has not made a request within their last TTL, they are removed from the set.

/** @var Zenstruck\Redis $client */

$set = $client->expiringSet('active-users');
$ttl = \DateInterval::createFromDateString('5 minutes');

// LOGIN EVENT:
$set->add($event->getUsername(), $ttl);

// LOGOUT EVENT:
$set->remove($event->getUsername());

// REQUEST EVENT:
$set->add($event->getUsername(), $ttl);

// ADMIN MONITORING DASHBOARD WIDGET
$activeUserCount = count($set);
$activeUsernames = $set->all(); // [user1, user2, ...]

// ADMIN USER CRUD LISTING
foreach ($users as $user) {
    $isActive = $set->contains($user->getUsername()); // bool
    // ...
}

Integrations

Symfony Framework

Add a supported Redis DSN environment variable:

# .env

REDIS_DSN=redis://localhost

Configure services:

# config/packages/zenstruck_redis.yaml

services:

    # Proxy that is autowireable
    Zenstruck\Redis:
        factory: ['Zenstruck\Redis', 'create']
        arguments: ['%env(REDIS_DSN)%']

    # Separate proxy's that have different prefixes
    redis1:
        class: Zenstruck\Redis
        factory: ['Zenstruck\Redis', 'create']
        arguments: ['%env(REDIS_DSN)%', { prefix: 'prefix1:' }]
    redis2:
        class: Zenstruck\Redis
        factory: ['Zenstruck\Redis', 'create']
        arguments: ['%env(REDIS_DSN)%', { prefix: 'prefix2:' }]

    # Separate proxy that uses PHP serialization
    serialization_redis:
        class: Zenstruck\Redis
        factory: ['Zenstruck\Redis', 'create']
        arguments: ['%env(REDIS_DSN)%', { serializer: php }]

    # expiring set service
    active_users:
        class: Zenstruck\Redis\Utility\ExpiringSet
        factory: ['@Zenstruck\Redis', 'expiringSet']
        arguments:
            - active_users # redis key

    # Specific clients that are autowireable
    Redis:
        class: Redis
        factory: ['Zenstruck\Redis', 'createClient']
        arguments: ['%env(REDIS_DSN)%'] # note REDIS_DSN must be for \Redis client

    RedisArray:
        class: RedisArray
        factory: ['Zenstruck\Redis', 'createClient']
        arguments: ['%env(REDIS_DSN)%'] # note REDIS_DSN must be for \RedisArray client

    RedisCluster:
        class: RedisCluster
        factory: ['Zenstruck\Redis', 'createClient']
        arguments: ['%env(REDIS_DSN)%'] # note REDIS_DSN must be for \RedisCluster client

Use Zenstruck\Redis for session storage (see Symfony Docs for more details/options):

# config/services.yaml

# Assumes "Zenstruck\Redis" is available as a service and symfony/expression-language is installed
services:
    redis_session_handler:
        class:  Symfony\Component\HttpFoundation\Session\Storage\Handler\RedisSessionHandler
        arguments:
            - "@=service('Zenstruck\\\\Redis').realClient()"

# config/packages/framework.yaml
framework:
    # ...
    session:
        handler_id: Symfony\Component\HttpFoundation\Session\Storage\Handler\RedisSessionHandler

Contributing

Running the test suite:

composer install
docker compose up -d # setup redis, redis-cluster, redis-sentinel
vendor/bin/phpunit -c phpunit.docker.xml

Credit

Much of the code to create php-redis clients from a DSN has been taken and modified from the Symfony Framework.