<?php

namespace BookStack\Util;

use Closure;

use Illuminate\Database\Connection;

use Illuminate\Support\Facades\DB;

use Throwable;

/**

* Run the given code within a database transactions.

* Wraps Laravel's own transaction method, but sets a specific runtime isolation method.

* This sets a session level since this won't cause issues if already within a transaction,

* and this should apply to the next transactions anyway.

*

* "READ COMMITTED" ensures that changes from other transactions can be read within

* a transaction, even if started afterward (and for example, it was blocked by the initial

* transaction). This is quite important for things like permission generation, where we would

* want to consider the changes made by other committed transactions by the time we come to

* regenerate permission access.

*

* @throws Throwable

* @template TReturn of mixed

*/

class DatabaseTransaction

{

/**

* @param (Closure(Connection): TReturn) $callback

*/

public function __construct(

protected Closure $callback

) {

}

/**

* @return TReturn

*/

public function run(): mixed

{

DB::statement('SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED');

return DB::transaction($this->callback);

}

}