PHP - laravel cache

Laravel Medium cache Three caching mechanisms are provided for us .

Redis,memcache, And the file cache of the framework .

What we mainly look at here is cache File cache in .

One ： Access multiple cache stores

Use Cache The facade , You can use store Method to access different cache memory , Pass in store The key of the method is cache In profile stores Configure the corresponding memory listed in the array ：

$value = Cache::store('file')->get('foo');
Cache::store('redis')->put('bar', 'baz', 600);  // 10 minute 

Two ： Get the data from the cache

1： Get the data and set the default value

（1）： Normal value

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

（2）： If it doesn't exist , With default value

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

（3）： Use closure operations , With default value

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

2： Check whether the cache item exists

has Method is used to determine whether the cache item exists , If the value is null or false This method returns false：

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

3： The value increases / Reduce

increment and decrement Method can be used to adjust integer values in the cache . Both methods can receive a second parameter to indicate the number of cache item values increasing and decreasing ：

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

4： obtain & Storage

Sometimes you may want to get cache entries , But if the requested cache item does not exist, store a default value for it . for example , You may want to get all users from the cache , Or if they don't exist , Get them from the database and add them to the cache , You can use Cache::remember Method realization ：

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

If the cache entry does not exist , Pass to remember The closure of the method is executed and the result is stored in the cache .

You can still use it rememberForever Method to get data from the cache or store it permanently ：

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

5： obtain & Delete

If you need to get cache entries from the cache and delete , You can use pull Method , and get The method is the same , If the cache item does not exist, return null：

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

3、 ... and ： Store data in cache

1： Getting stored data

You can use Cache On the facade put Method stores data in the cache . When you store data in the cache , You need to specify the time when the data is cached （ Number of seconds ）：

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

If the cache time is not delivered put Method , Then the cache entry is permanently valid ：

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

In addition to passing cache item expiration time , You can also pass a that represents the effective time of the cache item PHP Datetime example ：

$expiresAt = Carbon::now()->addMinutes(10);
Cache::put('key', 'value', $expiresAt);

2： Store data when cache does not exist

add Method will only add data to the cache if the cache item does not exist , Returns if the data is successfully added to the cache true, otherwise , return false：

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

3： Permanently store data

forever Method is used to persist stored data to the cache , These values must pass forget Method to manually remove from the cache ：

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

Four ： Remove data from cache

have access to Cache On the facade forget Method to remove cached item data from the cache ：

Cache::forget('key');

You can also set the cache validity to 0 Or negative numbers to remove cache entries ：

Cache::put('key', 'value', 0);
  
Cache::put('key', 'value', -5);

If you want to clear all caches , Can pass flush Method ：

Cache::flush();

The above is basically laravel The operation method of the framework for file caching

link ：https://www.jianshu.com/p/48d44d91ec93/