32 KiB
Cache
- Introduction
- Configuration
- Driver Prerequisites
- Cache Usage
- Obtaining a Cache Instance
- Retrieving Items From the Cache
- Storing Items in the Cache
- Removing Items From the Cache
- Cache Memoization
- The Cache Helper
- Atomic Locks
- Managing Locks
- Managing Locks Across Processes
- Adding Custom Cache Drivers
- Writing the Driver
- Registering the Driver
- Events
Introduction
Some of the data retrieval or processing tasks performed by your application could be CPU intensive or take several seconds to complete. When this is the case, it is common to cache the retrieved data for a time so it can be retrieved quickly on subsequent requests for the same data. The cached data is usually stored in a very fast data store such as Memcached or Redis.
Thankfully, Laravel provides an expressive, unified API for various cache backends, allowing you to take advantage of their blazing fast data retrieval and speed up your web application.
Configuration
Your application's cache configuration file is located at config/cache.php.
In this file, you may specify which cache store you would like to be used by
default throughout your application. Laravel supports popular caching backends
like Memcached, Redis,
DynamoDB, and relational databases out of
the box. In addition, a file based cache driver is available, while array
and null cache drivers provide convenient cache backends for your automated
tests.
The cache configuration file also contains a variety of other options that you
may review. By default, Laravel is configured to use the database cache
driver, which stores the serialized, cached objects in your application's
database.
Driver Prerequisites
Database
When using the database cache driver, you will need a database table to
contain the cache data. Typically, this is included in Laravel's default
0001_01_01_000001_create_cache_table.php database
migration; however, if your application does not
contain this migration, you may use the make:cache-table Artisan command to
create it:
1php artisan make:cache-table
2
3php artisan migrate
php artisan make:cache-table
php artisan migrate
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.
This file already contains a memcached.servers entry to get you started:
1'memcached' => [
2 // ...
3
4 'servers' => [
5 [
6 'host' => env('MEMCACHED_HOST', '127.0.0.1'),
7 'port' => env('MEMCACHED_PORT', 11211),
8 'weight' => 100,
9 ],
10 ],
11],
'memcached' => [
// ...
'servers' => [
[
'host' => env('MEMCACHED_HOST', '127.0.0.1'),
'port' => env('MEMCACHED_PORT', 11211),
'weight' => 100,
],
],
],
If needed, you may set the host option to a UNIX socket path. If you do
this, the port option should be set to 0:
1'memcached' => [
2 // ...
3
4 'servers' => [
5 [
6 'host' => '/var/run/memcached/memcached.sock',
7 'port' => 0,
8 'weight' => 100
9 ],
10 ],
11],
'memcached' => [
// ...
'servers' => [
[
'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
PhpRedis PHP extension via PECL or install the predis/predis package (~2.0)
via Composer. Laravel Sail already includes this extension.
In addition, official Laravel application platforms such as Laravel
Cloud and Laravel
Forge have the PhpRedis extension installed by
default.
For more information on configuring Redis, consult its Laravel documentation page.
DynamoDB
Before using the DynamoDB cache driver, you
must create a DynamoDB table to store all of the cached data. Typically, this
table should be named cache. However, you should name the table based on the
value of the stores.dynamodb.table configuration value within the cache
configuration file. The table name may also be set via the
DYNAMODB_CACHE_TABLE environment variable.
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.
Typically, DynamoDB will not proactively remove expired items from a table.
Therefore, you should enable Time to Live
(TTL)
on the table. When configuring the table's TTL settings, you should set the
TTL attribute name to expires_at.
Next, install the AWS SDK so that your Laravel application can communicate with DynamoDB:
1composer require aws/aws-sdk-php
composer require aws/aws-sdk-php
In addition, you should ensure that values are provided for the DynamoDB cache
store configuration options. Typically these options, such as
AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY, should be defined in your
application's .env configuration file:
1'dynamodb' => [
2 'driver' => 'dynamodb',
3 'key' => env('AWS_ACCESS_KEY_ID'),
4 'secret' => env('AWS_SECRET_ACCESS_KEY'),
5 'region' => env('AWS_DEFAULT_REGION', 'us-east-1'),
6 'table' => env('DYNAMODB_CACHE_TABLE', 'cache'),
7 'endpoint' => env('DYNAMODB_ENDPOINT'),
8],
'dynamodb' => [
'driver' => 'dynamodb',
'key' => env('AWS_ACCESS_KEY_ID'),
'secret' => env('AWS_SECRET_ACCESS_KEY'),
'region' => env('AWS_DEFAULT_REGION', 'us-east-1'),
'table' => env('DYNAMODB_CACHE_TABLE', 'cache'),
'endpoint' => env('DYNAMODB_ENDPOINT'),
],
MongoDB
If you are using MongoDB, a mongodb cache driver is provided by the official
mongodb/laravel-mongodb package and can be configured using a mongodb
database connection. MongoDB supports TTL indexes, which can be used to
automatically clear expired cache items.
For more information on configuring MongoDB, please refer to the MongoDB [Cache and Locks documentation](https://www.mongodb.com/docs/drivers/php/laravel- mongodb/current/cache/).
Cache Usage
Obtaining a Cache Instance
To obtain a cache store instance, you may 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:
1<?php
2
3namespace App\Http\Controllers;
4
5use Illuminate\Support\Facades\Cache;
6
7class UserController extends Controller
8{
9 /**
10 * Show a list of all users of the application.
11 */
12 public function index(): array
13 {
14 $value = Cache::get('key');
15
16 return [
17 // ...
18 ];
19 }
20}
<?php
namespace App\Http\Controllers;
use Illuminate\Support\Facades\Cache;
class UserController extends Controller
{
/**
* Show a list of all users of the application.
*/
public function index(): array
{
$value = Cache::get('key');
return [
// ...
];
}
}
Accessing Multiple Cache Stores
Using the Cache facade, you may access various cache stores via the store
method. The key passed to the store method should correspond to one of the
stores listed in the stores configuration array in your cache
configuration file:
1$value = Cache::store('file')->get('foo');
2
3Cache::store('redis')->put('bar', 'baz', 600); // 10 Minutes
$value = Cache::store('file')->get('foo');
Cache::store('redis')->put('bar', 'baz', 600); // 10 Minutes
Retrieving Items From the Cache
The Cache facade's get method is used to retrieve items from the cache. If
the item does not exist in the cache, null will be returned. If you wish,
you may pass a second argument to the get method specifying the default
value you wish to be returned if the item doesn't exist:
1$value = Cache::get('key');
2
3$value = Cache::get('key', 'default');
$value = Cache::get('key');
$value = Cache::get('key', 'default');
You may even pass a closure as the default value. The result of the closure will be returned if the specified item does not exist in the cache. Passing a closure allows you to defer the retrieval of default values from a database or other external service:
1$value = Cache::get('key', function () {
2 return DB::table(/* ... */)->get();
3});
$value = Cache::get('key', function () {
return DB::table(/* ... */)->get();
});
Determining Item Existence
The has method may be used to determine if an item exists in the cache. This
method will also return false if the item exists but its value is null:
1if (Cache::has('key')) {
2 // ...
3}
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:
1// Initialize the value if it does not exist...
2Cache::add('key', 0, now()->addHours(4));
3
4// Increment or decrement the value...
5Cache::increment('key');
6Cache::increment('key', $amount);
7Cache::decrement('key');
8Cache::decrement('key', $amount);
// Initialize the value if it does not exist...
Cache::add('key', 0, now()->addHours(4));
// Increment or decrement the value...
Cache::increment('key');
Cache::increment('key', $amount);
Cache::decrement('key');
Cache::decrement('key', $amount);
Retrieve and Store
Sometimes you may wish to retrieve an item from the cache, but also store a
default value if the requested item doesn't exist. For example, you may wish
to retrieve all users from the cache or, if they don't exist, retrieve them
from the database and add them to the cache. You may do this using the
Cache::remember method:
1$value = Cache::remember('users', $seconds, function () {
2 return DB::table('users')->get();
3});
$value = Cache::remember('users', $seconds, function () {
return DB::table('users')->get();
});
If the item does not exist in the cache, the closure passed to the remember
method will be executed and its result will be placed in the cache.
You may use the rememberForever method to retrieve an item from the cache or
store it forever if it does not exist:
1$value = Cache::rememberForever('users', function () {
2 return DB::table('users')->get();
3});
$value = Cache::rememberForever('users', function () {
return DB::table('users')->get();
});
Stale While Revalidate
When using the Cache::remember method, some users may experience slow
response times if the cached value has expired. For certain types of data, it
can be useful to allow partially stale data to be served while the cached
value is recalculated in the background, preventing some users from
experiencing slow response times while cached values are calculated. This is
often referred to as the "stale-while-revalidate" pattern, and the
Cache::flexible method provides an implementation of this pattern.
The flexible method accepts an array that specifies how long the cached value is considered “fresh” and when it becomes “stale.” The first value in the array represents the number of seconds the cache is considered fresh, while the second value defines how long it can be served as stale data before recalculation is necessary.
If a request is made within the fresh period (before the first value), the cache is returned immediately without recalculation. If a request is made during the stale period (between the two values), the stale value is served to the user, and a deferred function is registered to refresh the cached value after the response is sent to the user. If a request is made after the second value, the cache is considered expired, and the value is recalculated immediately, which may result in a slower response for the user:
1$value = Cache::flexible('users', [5, 10], function () {
2 return DB::table('users')->get();
3});
$value = Cache::flexible('users', [5, 10], function () {
return DB::table('users')->get();
});
Retrieve and Delete
If you need to retrieve an item from the cache and then delete the item, you
may use the pull method. Like the get method, null will be returned if
the item does not exist in the cache:
1$value = Cache::pull('key');
2
3$value = Cache::pull('key', 'default');
$value = Cache::pull('key');
$value = Cache::pull('key', 'default');
Storing Items in the Cache
You may use the put method on the Cache facade to store items in the
cache:
1Cache::put('key', 'value', $seconds = 10);
Cache::put('key', 'value', $seconds = 10);
If the storage time is not passed to the put method, the item will be stored
indefinitely:
1Cache::put('key', 'value');
Cache::put('key', 'value');
Instead of passing the number of seconds as an integer, you may also pass a
DateTime instance representing the desired expiration time of the cached
item:
1Cache::put('key', 'value', now()->addMinutes(10));
Cache::put('key', 'value', now()->addMinutes(10));
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. The
add method is an atomic operation:
1Cache::add('key', 'value', $seconds);
Cache::add('key', 'value', $seconds);
Storing Items Forever
The forever method may be used to store an item in the cache permanently.
Since these items will not expire, they must be manually removed from the
cache using the forget method:
1Cache::forever('key', 'value');
Cache::forever('key', 'value');
If you are using the Memcached driver, items that are stored "forever" may be removed when the cache reaches its size limit.
Removing Items From the Cache
You may remove items from the cache using the forget method:
1Cache::forget('key');
Cache::forget('key');
You may also remove items by providing a zero or negative number of expiration seconds:
1Cache::put('key', 'value', 0);
2
3Cache::put('key', 'value', -5);
Cache::put('key', 'value', 0);
Cache::put('key', 'value', -5);
You may clear the entire cache using the flush method:
1Cache::flush();
Cache::flush();
Flushing the cache does not respect your configured cache "prefix" and will remove all entries from the cache. Consider this carefully when clearing a cache which is shared by other applications.
Cache Memoization
Laravel's memo cache driver allows you to temporarily store resolved cache
values in memory during a single request or job execution. This prevents
repeated cache hits within the same execution, significantly improving
performance.
To use the memoized cache, invoke the memo method:
1use Illuminate\Support\Facades\Cache;
2
3$value = Cache::memo()->get('key');
use Illuminate\Support\Facades\Cache;
$value = Cache::memo()->get('key');
The memo method optionally accepts the name of a cache store, which
specifies the underlying cache store the memoized driver will decorate:
1// Using the default cache store...
2$value = Cache::memo()->get('key');
3
4// Using the Redis cache store...
5$value = Cache::memo('redis')->get('key');
// Using the default cache store...
$value = Cache::memo()->get('key');
// Using the Redis cache store...
$value = Cache::memo('redis')->get('key');
The first get call for a given key retrieves the value from your cache
store, but subsequent calls within the same request or job will retrieve the
value from memory:
1// Hits the cache...
2$value = Cache::memo()->get('key');
3
4// Does not hit the cache, returns memoized value...
5$value = Cache::memo()->get('key');
// Hits the cache...
$value = Cache::memo()->get('key');
// Does not hit the cache, returns memoized value...
$value = Cache::memo()->get('key');
When calling methods that modify cache values (such as put, increment,
remember, etc.), the memoized cache automatically forgets the memoized value
and delegates the mutating method call to the underlying cache store:
1Cache::memo()->put('name', 'Taylor'); // Writes to underlying cache...
2Cache::memo()->get('name'); // Hits underlying cache...
3Cache::memo()->get('name'); // Memoized, does not hit cache...
4
5Cache::memo()->put('name', 'Tim'); // Forgets memoized value, writes new value...
6Cache::memo()->get('name'); // Hits underlying cache again...
Cache::memo()->put('name', 'Taylor'); // Writes to underlying cache...
Cache::memo()->get('name'); // Hits underlying cache...
Cache::memo()->get('name'); // Memoized, does not hit cache...
Cache::memo()->put('name', 'Tim'); // Forgets memoized value, writes new value...
Cache::memo()->get('name'); // Hits underlying cache again...
The Cache Helper
In addition to using the Cache facade, you may also use the global cache
function to retrieve and store data via the cache. When the cache function
is called with a single, string argument, it will return the value of the
given key:
1$value = cache('key');
$value = cache('key');
If you provide an array of key / value pairs and an expiration time to the function, it will store values in the cache for the specified duration:
1cache(['key' => 'value'], $seconds);
2
3cache(['key' => 'value'], now()->addMinutes(10));
cache(['key' => 'value'], $seconds);
cache(['key' => 'value'], now()->addMinutes(10));
When the cache function is called without any arguments, it returns an
instance of the Illuminate\Contracts\Cache\Factory implementation, allowing
you to call other caching methods:
1cache()->remember('users', $seconds, function () {
2 return DB::table('users')->get();
3});
cache()->remember('users', $seconds, function () {
return DB::table('users')->get();
});
When testing calls to the global cache function, you may use the
Cache::shouldReceive method just as if you were testing the
facade.
Atomic Locks
To utilize this feature, your application must be using the memcached,
redis, dynamodb, database, file, or array cache driver as your
application's default cache driver. In addition, all servers must be
communicating with the same central cache server.
Managing Locks
Atomic locks allow for the manipulation of distributed locks without worrying
about race conditions. For example, Laravel Cloud
uses atomic locks to ensure that only one remote task is being executed on a
server at a time. You may create and manage locks using the Cache::lock
method:
1use Illuminate\Support\Facades\Cache;
2
3$lock = Cache::lock('foo', 10);
4
5if ($lock->get()) {
6 // Lock acquired for 10 seconds...
7
8 $lock->release();
9}
use Illuminate\Support\Facades\Cache;
$lock = Cache::lock('foo', 10);
if ($lock->get()) {
// Lock acquired for 10 seconds...
$lock->release();
}
The get method also accepts a closure. After the closure is executed,
Laravel will automatically release the lock:
1Cache::lock('foo', 10)->get(function () {
2 // Lock acquired for 10 seconds and automatically released...
3});
Cache::lock('foo', 10)->get(function () {
// Lock acquired for 10 seconds and automatically released...
});
If the lock is not available at the moment you request it, you may instruct
Laravel to wait for a specified number of seconds. If the lock cannot be
acquired within the specified time limit, an
Illuminate\Contracts\Cache\LockTimeoutException will be thrown:
1use Illuminate\Contracts\Cache\LockTimeoutException;
2
3$lock = Cache::lock('foo', 10);
4
5try {
6 $lock->block(5);
7
8 // Lock acquired after waiting a maximum of 5 seconds...
9} catch (LockTimeoutException $e) {
10 // Unable to acquire lock...
11} finally {
12 $lock->release();
13}
use Illuminate\Contracts\Cache\LockTimeoutException;
$lock = Cache::lock('foo', 10);
try {
$lock->block(5);
// Lock acquired after waiting a maximum of 5 seconds...
} catch (LockTimeoutException $e) {
// Unable to acquire lock...
} finally {
$lock->release();
}
The example above may be simplified by passing a closure to the block
method. When a closure is passed to this method, Laravel will attempt to
acquire the lock for the specified number of seconds and will automatically
release the lock once the closure has been executed:
1Cache::lock('foo', 10)->block(5, function () {
2 // Lock acquired for 10 seconds after waiting a maximum of 5 seconds...
3});
Cache::lock('foo', 10)->block(5, function () {
// Lock acquired for 10 seconds after waiting a maximum of 5 seconds...
});
Managing Locks Across Processes
Sometimes, you may wish to acquire a lock in one process and release it in another process. For example, you may acquire a lock during a web request and wish to release the lock at the end of a queued job that is triggered by that request. In this scenario, you should pass the lock's scoped "owner token" to the queued job so that the job can re-instantiate the lock using the given token.
In the example below, we will dispatch a queued job if a lock is successfully
acquired. In addition, we will pass the lock's owner token to the queued job
via the lock's owner method:
1$podcast = Podcast::find($id);
2
3$lock = Cache::lock('processing', 120);
4
5if ($lock->get()) {
6 ProcessPodcast::dispatch($podcast, $lock->owner());
7}
$podcast = Podcast::find($id);
$lock = Cache::lock('processing', 120);
if ($lock->get()) {
ProcessPodcast::dispatch($podcast, $lock->owner());
}
Within our application's ProcessPodcast job, we can restore and release the
lock using the owner token:
1Cache::restoreLock('processing', $this->owner)->release();
Cache::restoreLock('processing', $this->owner)->release();
If you would like to release a lock without respecting its current owner, you
may use the forceRelease method:
1Cache::lock('processing')->forceRelease();
Cache::lock('processing')->forceRelease();
Adding Custom Cache Drivers
Writing the Driver
To create our custom cache driver, we first need to implement the
Illuminate\Contracts\Cache\Store contract. So, a
MongoDB cache implementation might look something like this:
1<?php
2
3namespace App\Extensions;
4
5use Illuminate\Contracts\Cache\Store;
6
7class MongoStore implements Store
8{
9 public function get($key) {}
10 public function many(array $keys) {}
11 public function put($key, $value, $seconds) {}
12 public function putMany(array $values, $seconds) {}
13 public function increment($key, $value = 1) {}
14 public function decrement($key, $value = 1) {}
15 public function forever($key, $value) {}
16 public function forget($key) {}
17 public function flush() {}
18 public function getPrefix() {}
19}
<?php
namespace App\Extensions;
use Illuminate\Contracts\Cache\Store;
class MongoStore implements Store
{
public function get($key) {}
public function many(array $keys) {}
public function put($key, $value, $seconds) {}
public function putMany(array $values, $seconds) {}
public function increment($key, $value = 1) {}
public function decrement($key, $value = 1) {}
public function forever($key, $value) {}
public function forget($key) {}
public function flush() {}
public function getPrefix() {}
}
We just need to implement each of these methods using a MongoDB connection.
For an example of how to implement each of these methods, take a look at the
Illuminate\Cache\MemcachedStore in the Laravel framework source
code. Once our implementation is
complete, we can finish our custom driver registration by calling the Cache
facade's extend method:
1Cache::extend('mongo', function (Application $app) {
2 return Cache::repository(new MongoStore);
3});
Cache::extend('mongo', function (Application $app) {
return Cache::repository(new MongoStore);
});
If you're wondering where to put your custom cache driver code, you could
create an Extensions namespace within your app directory. However, keep in
mind that Laravel does not have a rigid application structure and you are free
to organize your application according to your preferences.
Registering the Driver
To register the custom cache driver with Laravel, we will use the extend
method on the Cache facade. Since other service providers may attempt to
read cached values within their boot method, we will register our custom
driver within a booting callback. By using the booting callback, we can
ensure that the custom driver is registered just before the boot method is
called on our application's service providers but after the register method
is called on all of the service providers. We will register our booting
callback within the register method of our application's
App\Providers\AppServiceProvider class:
1<?php
2
3namespace App\Providers;
4
5use App\Extensions\MongoStore;
6use Illuminate\Contracts\Foundation\Application;
7use Illuminate\Support\Facades\Cache;
8use Illuminate\Support\ServiceProvider;
9
10class AppServiceProvider extends ServiceProvider
11{
12 /**
13 * Register any application services.
14 */
15 public function register(): void
16 {
17 $this->app->booting(function () {
18 Cache::extend('mongo', function (Application $app) {
19 return Cache::repository(new MongoStore);
20 });
21 });
22 }
23
24 /**
25 * Bootstrap any application services.
26 */
27 public function boot(): void
28 {
29 // ...
30 }
31}
<?php
namespace App\Providers;
use App\Extensions\MongoStore;
use Illuminate\Contracts\Foundation\Application;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\ServiceProvider;
class AppServiceProvider extends ServiceProvider
{
/**
* Register any application services.
*/
public function register(): void
{
$this->app->booting(function () {
Cache::extend('mongo', function (Application $app) {
return Cache::repository(new MongoStore);
});
});
}
/**
* Bootstrap any application services.
*/
public function boot(): void
{
// ...
}
}
The first argument passed to the extend method is the name of the driver.
This will correspond to your driver option in the config/cache.php
configuration file. The second argument is a closure that should return an
Illuminate\Cache\Repository instance. The closure will be passed an $app
instance, which is an instance of the service
container.
Once your extension is registered, update the CACHE_STORE environment
variable or default option within your application's config/cache.php
configuration file to the name of your extension.
Events
To execute code on every cache operation, you may listen for various events dispatched by the cache:
Event Name
Illuminate\Cache\Events\CacheFlushed
Illuminate\Cache\Events\CacheFlushing
Illuminate\Cache\Events\CacheHit
Illuminate\Cache\Events\CacheMissed
Illuminate\Cache\Events\ForgettingKey
Illuminate\Cache\Events\KeyForgetFailed
Illuminate\Cache\Events\KeyForgotten
Illuminate\Cache\Events\KeyWriteFailed
Illuminate\Cache\Events\KeyWritten
Illuminate\Cache\Events\RetrievingKey
Illuminate\Cache\Events\RetrievingManyKeys
Illuminate\Cache\Events\WritingKey
Illuminate\Cache\Events\WritingManyKeys
To increase performance, you may disable cache events by setting the events
configuration option to false for a given cache store in your application's
config/cache.php configuration file:
1'database' => [
2 'driver' => 'database',
3 // ...
4 'events' => false,
5],
'database' => [
'driver' => 'database',
// ...
'events' => false,
],