frameworkが提供するCacheがよーわからん。
Configuration
Laravel provides an expressive, unified API for various caching backends. The cache configuration is located at config/cache.php. In this file you may specify which cache driver you would like to be used by default throughout your application. Laravel supports popular caching backends like Memcached and Redis 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, Laravel 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 a more robust driver such as Memcached or Redis. You may even configure multiple cache configurations for the same driver.
Driver Prerequisites
Database
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');
});
Memcached
Using the Memcached driver requires the Memcached PECL package to be installed. You may list all of your Memcached servers in the config/cache.php configuration file:
'memcached' => [
[
'host' => '127.0.0.1',
'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
Before using a Redis cache with Laravel, you will need to either install the predis/predis package (~1.0) via Composer or install the PhpRedis PHP extension via PECL.
For more information on configuring Redis, consult its Laravel documentation page.
Obtaining A Cache Instance
The Illuminate\Contracts\Cache\Factory and Illuminate\Contracts\Cache\Repository contracts provide access to Laravel’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 Laravel cache contracts:
namespace App\Http\Controllers;
use Illuminate\Support\Facades\Cache;
class UserController extends Controller
{
/**
* Show a list of all users of the application.
*
* @return Response
*/
public function index()
{
$value = Cache::get('key');
//
}
}
Accessing Multiple Cache Stores
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);
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 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. This method will return false if the value is null or false:
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 accept an optional 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 & Store
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 use the rememberForever method to retrieve an item from the cache or store it forever:
$value = Cache::rememberForever(‘users’, function () {
return DB::table(‘users’)->get();
});
Retrieve & Delete
If you need to retrieve an item from the cache and then delete the item, 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 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 as an integer, you may also pass a DateTime instance representing the expiration time of the cached item:
$expiresAt = now()->addMinutes(10);
Cache::put(‘key’, ‘value’, $expiresAt);
Store If Not Present
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);
Storing Items Forever
The forever method may be used to store an item in the cache permanently. Since these items will not expire, they must be manually removed from the cache using the forget method:
Cache::forever(‘key’, ‘value’);
Tip!! If you are using the Memcached driver, items that are stored “forever” may be removed when the cache reaches its size limit.
Removing Items From The Cache
You may remove items from the cache using the forget method:
Cache::forget(‘key’);
You may clear the entire cache using the flush method:
Cache::flush();
Note: 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.