Lumen provides a unified API for various caching systems. The cache configuration is located in your application's env file. In this file you may specify which cache driver you would like used by default throughout your application. Lumen supports popular caching backends like Memcached and Redis out of the box. For larger applications, it is recommended that you use an in-memory cache such as Memcached or APC.
When using the database cache driver, you will need to setup a table to contain the cache items. You'll find an example Schema declaration for the table below:
Schema::create('cache', function($table) {
$table->string('key')->unique();
$table->text('value');
$table->integer('expiration');
});
Using the Memcached cache requires the Memcached PECL package to be installed. The default configuration uses TCP/IP based on Memcached::addServer.
Before using a Redis cache with Lumen, you will need to install the predis/predis package (~1.0) and illuminate/redis package (~5.1) via Composer.
The Illuminate\Contracts\Cache\Factory and Illuminate\Contracts\Cache\Repository contracts provide access to Lumen's cache services. The Factory contract provides access to all cache drivers defined for your application. The Repository contract is typically an implementation of the default cache driver for your application as specified by your cache configuration file.
However, you may also use the Cache facade, which is what we will use throughout this documentation. The Cache facade provides convenient, terse access to the underlying implementations of the Lumen cache contracts.
For example, let's import the Cache facade into a controller:
<?php
namespace App\Http\Controllers;
use Cache;
class UserController extends Controller
{
/**
* Show a list of all users of the application.
*
* @return Response
*/
public function index()
{
$value = Cache::get('key');
//
}
}
Using the Cache facade, you may access various cache stores via the store method. The key passed to the store method should correspond to one of the stores listed in the stores configuration array in your cache configuration file:
$value = Cache::store('file')->get('foo');
Cache::store('redis')->put('bar', 'baz', 10);
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();
});
The has method may be used to determine if an item exists in the cache:
if (Cache::has('key')) {
//
}
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);
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', $minutes, 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();
});
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');
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 minutes for which the value should be cached:
Cache::put('key', 'value', $minutes);
Instead of passing the number of minutes 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);
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', $minutes);
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');
You may remove items from the cache using the forget method on the Cache facade:
Cache::forget('key');