PHP code example of mpyw / laravel-database-advisory-lock

1. Go to this page and download the library: Download mpyw/laravel-database-advisory-lock library. Choose the download type require.

2. Extract the ZIP file and open the index.php.

3. Add this code to the index.php. 
    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

mpyw / laravel-database-advisory-lock example snippets




return [

    /* ... */

    'providers' => [
        /* ... */

        Mpyw\LaravelDatabaseAdvisoryLock\ConnectionServiceProvider::class,

        /* ... */
    ],

];




use Illuminate\Support\Facades\DB;
use Illuminate\Database\ConnectionInterface;

// Session-Level Locking
$result = DB::advisoryLocker()
    ->forSession()
    ->withLocking('<key>', function (ConnectionInterface $conn) {
        // critical section here
        return ...;
    }); // no wait
$result = DB::advisoryLocker()
    ->forSession()
    ->withLocking('<key>', function (ConnectionInterface $conn) {
        // critical section here
        return ...;
    }, timeout: 5); // wait for 5 seconds or fail
$result = DB::advisoryLocker()
    ->forSession()
    ->withLocking('<key>', function (ConnectionInterface $conn) {
        // critical section here
        return ...;
    }, timeout: -1); // infinite wait (except MariaDB)

// Postgres only feature: Transaction-Level Locking (no wait)
$result = DB::transaction(function (ConnectionInterface $conn) {
    $conn->advisoryLocker()->forTransaction()->lockOrFail('<key>');
    // critical section here
    return ...;
});




namespace App\Providers;

use App\Database\PostgresConnection;
use Illuminate\Database\Connection;
use Illuminate\Support\ServiceProvider;

class DatabaseServiceProvider extends ServiceProvider
{
    public function register(): void
    {
        Connection::resolverFor('pgsql', function (...$parameters) {
            return new PostgresConnection(...$parameters);
        });
    }
}




namespace App\Database;

use Illuminate\Database\PostgresConnection as BasePostgresConnection;
use Mpyw\LaravelDatabaseAdvisoryLock\AdvisoryLocks;

class PostgresConnection extends BasePostgresConnection
{
    use AdvisoryLocks;
}


> if (DB::transactionLevel() > 1) {
>     throw new LogicException("Don't use nested transactions outside of this logic.");
> }
>
> DB::advisoryLocker()
>     ->forTransaction()
>     ->lockOrFail('<key>');
> // critical section with transaction here
> 

> if (DB::transactionLevel() > 0) {
>     throw new LogicException("Don't use transactions outside of this logic.");
> }
>
> $result = DB::advisoryLocker()
>     ->forSession()
>     ->withLocking('<key>', fn (ConnectionInterface $conn) => $conn->transaction(function () {
>         // critical section with transaction here
>     }));
>