Cache

# Configuration

October CMS provides a unified API for various caching systems and the cache configuration is located at config/cache.php. In this file you may specify which cache driver you would like used by default throughout your application. Popular caching systems like Memcached (opens new window) and Redis (opens new window) are supported out of the box.

The cache configuration file also contains various other options, which are documented within the file, so make sure to read over these options. By default, October CMS is configured to use the file cache driver which stores the serialized, cached objects in the filesystem. For larger applications, it is recommended that you use an in-memory cache such as Memcached or APC. You may even configure multiple cache configurations for the same driver.

# Cache Prerequisites

# Database

The database cache driver uses the database in lieu of the file system. There is no other configuration required to use this type as the database structure is already available.

# Memcached

Using the Memcached cache requires the Memcached PECL package (opens new window) to be installed. The default configuration uses TCP/IP based on Memcached::addServer (opens new window).

'memcached' => [
    'servers' => [
        [
            'host' => env('MEMCACHED_HOST', '127.0.0.1'),
            'port' => env('MEMCACHED_PORT', 11211),
            'weight' => 100,
        ],
    ],
],

You may also set the host option to a UNIX socket path. If you do this, the port option should be set to 0.

'memcached' => [
    [
        'host' => '/var/run/memcached/memcached.sock',
        'port' => 0,
        'weight' => 100
    ],
],

# Redis

The Redis configuration for your application is located in the config/database.php configuration file. Within this file, you will see a redis array containing the Redis servers used by your application:

'redis' => [

    'cluster' => false,

    'default' => [
        'host'     => '127.0.0.1',
        'port'     => 6379,
        'database' => 0,
    ],

],

You may define an options array value in your Redis connection definition, allowing you to specify a set of Predis client options (opens new window).

If your Redis server requires authentication, you may supply a password by adding a password configuration item to your Redis server configuration array.

# DynamoDB

Before using the DynamoDB cache driver, you should create a DynamoDB cache table to store all of the cached data, typically it is named cache. You can name the table anything based on the value of the stores.dynamodb.table configuration value within your application's cache configuration file.

'dynamodb' => [
    'table' => env('DYNAMODB_CACHE_TABLE', 'cache'),
],

This table should also have a string partition key with a name that corresponds to the value of the stores.dynamodb.attributes.key configuration item within your application's cache configuration file. By default, the partition key should be named key.

# Cache Usage

While most caching is handled internally by October, the Cache facade provides some simple methods for caching your own data.

# Retrieving Items from the Cache

The get method on the Cache facade is used to retrieve items from the cache. If the item does not exist in the cache, null will be returned. If you wish, you may pass a second argument to the get method specifying the custom default value you wish to be returned if the item doesn't exist:

$value = Cache::get('key');

$value = Cache::get('key', 'default');

You may even pass a Closure as the default value. The result of the Closure will be returned if the specified item does not exist in the cache. Passing a Closure allows you to defer the retrieval of default values from a database or other external service:

$value = Cache::get('key', function() {
    return Db::table(...)->get();
});

# Checking for Item Existence

The has method may be used to determine if an item exists in the cache:

if (Cache::has('key')) {
    //
}

# Incrementing / Decrementing Values

The increment and decrement methods may be used to adjust the value of integer items in the cache. Both of these methods optionally accept a second argument indicating the amount by which to increment or decrement the item's value:

Cache::increment('key');

Cache::increment('key', $amount);

Cache::decrement('key');

Cache::decrement('key', $amount);

# Retrieve or Update

Sometimes you may wish to retrieve an item from the cache, but also store a default value if the requested item doesn't exist. For example, you may wish to retrieve all users from the cache or, if they don't exist, retrieve them from the database and add them to the cache. You may do this using the Cache::remember method:

$value = Cache::remember('users', $seconds, function() {
    return Db::table('users')->get();
});

If the item does not exist in the cache, the Closure passed to the remember method will be executed and its result will be placed in the cache.

You may also combine the remember and forever methods:

$value = Cache::rememberForever('users', function() {
    return Db::table('users')->get();
});

# Retrieve and Delete

If you need to retrieve an item from the cache and then delete it, you may use the pull method. Like the get method, null will be returned if the item does not exist in the cache:

$value = Cache::pull('key');

# Storing Items in the Cache

You may use the put method on the Cache facade to store items in the cache. When you place an item in the cache, you will need to specify the number of seconds for which the value should be cached:

Cache::put('key', 'value', $seconds);

Instead of passing the number of seconds until the item expires, you may also pass a PHP DateTime instance representing the expiration time of the cached item:

$expiresAt = Carbon::now()->addMinutes(10);

Cache::put('key', 'value', $expiresAt);

Note: We recommend using DateTime instances for defining all expiry lengths, in order to ensure compatibility with future versions of October CMS.

The add method will only add the item to the cache if it does not already exist in the cache store. The method will return true if the item is actually added to the cache. Otherwise, the method will return false:

Cache::add('key', 'value', $seconds);

The forever method may be used to store an item in the cache permanently. These values must be manually removed from the cache using the forget method:

Cache::forever('key', 'value');

# Removing Items from the Cache

You may remove items from the cache using the forget method on the Cache facade:

Cache::forget('key');

You may clear the entire caching using the flush method:

Cache::flush();

Flushing the cache does not respect the cache prefix and will remove all entries from the cache. Consider this carefully when clearing a cache which is shared by other applications.