Added ability to lock a table before and after the database transaction.

src/Transaction.php

@@ -23,6 +23,12 @@ abstract class Transaction
 		 */
 		protected ?string $event = null;
 
+		/**
+		 * @var string|null $lockTableName Specifies the name of the table to
+		 * optionally acquire a lock on for writing.
+		 */
+		protected ?string $lockTableName = null;
+
 		/**
 		 * Performs the action.
 		 * @throws Throwable
@@ -34,6 +40,25 @@ private function validateAndPerform(): self
 			$this->perform();
 			return $this;
 		}
+
+		/**
+		 * @throws Throwable
+		 */
+		private function lockTableIfNecessary()
+		{
+			if (!$this->lockTableName)
+				return;
+
+			DB::raw("LOCK TABLES `$this->lockTableName` WRITE");
+		}
+
+		private function unlockTableIfNecessary()
+		{
+			if (!$this->lockTableName)
+				return;
+
+			DB::raw("UNLOCK TABLES");
+		}
 
 		/**
 		 * Executes the transaction inside a database transaction context. If an
@@ -46,13 +71,18 @@ public function execute(): self
 		{
 			try
 			{
+				$this->lockTableIfNecessary();
 				DB::transaction(fn() => $this->validateAndPerform());
 			}
 			catch(Throwable $exception)
 			{
 				$this->cleanupAfterFailure();
 				throw $exception;
 			}
+			finally
+			{
+				$this->unlockTableIfNecessary();
+			}
 			$this->fireEvent();
 			return $this;
 		}

tests/TableLockTransactonTests.php

@@ -0,0 +1,43 @@
+<?php
+	/** @noinspection PhpUnhandledExceptionInspection */
+
+	namespace YetAnother\Tests;
+
+	use Illuminate\Database\Schema\Blueprint;
+	use Illuminate\Support\Facades\DB;
+	use Illuminate\Support\Facades\Schema;
+	use YetAnother\Tests\Transactions\TableLockTransaction;
+
+	class TableLockTransactonTests extends TestCase
+	{
+		protected function setUp(): void
+		{
+			parent::setUp();
+
+			Schema::create(TableLockTransaction::TableName, function(Blueprint $table)
+			{
+				$table->integer('a');
+				$table->integer('b');
+				$table->integer('c');
+			});
+		}
+
+		protected function tearDown(): void
+		{
+			Schema::drop(TableLockTransaction::TableName);
+
+			parent::tearDown();
+		}
+
+		function testLockedTableInsertDoesNotThrow()
+		{
+			(new TableLockTransaction())->execute();
+
+			/** @noinspection SqlNoDataSourceInspection */
+			$row = DB::selectOne('SELECT * FROM `' . TableLockTransaction::TableName . '`');
+
+			$this->assertEquals(1, $row->a);
+			$this->assertEquals(2, $row->b);
+			$this->assertEquals(3, $row->c);
+		}
+	}

tests/Transactions/TableLockTransaction.php

@@ -0,0 +1,21 @@
+<?php
+	namespace YetAnother\Tests\Transactions;
+
+	use Illuminate\Support\Facades\DB;
+	use YetAnother\Laravel\Transaction;
+
+	class TableLockTransaction extends Transaction
+	{
+		const TableName = 'LockedTable';
+
+		public function __construct()
+		{
+			$this->lockTableName = self::TableName;
+		}
+
+		protected function perform(): void
+		{
+			/** @noinspection SqlNoDataSourceInspection */
+			DB::insert("INSERT INTO `$this->lockTableName` VALUES(1, 2, 3)");
+		}
+	}