add skipLocked config

Author: michalsn

docs/configuration.md

@@ -37,6 +37,7 @@ The configuration settings for `database` handler.
 
 * `dbGroup` - The database group to use. Default value: `default`.
 * `getShared` - Weather to use shared instance. Default value: `true`.
+* `skipLocked` - Weather to use "skip locked" feature to maintain concurrency calls. Default to `true`.
 
 ### $redis
 

docs/running-queues.md

@@ -65,7 +65,7 @@ This way, worker will consume jobs with the `low` priority and then with `high`.
 
 ### Running many instances of the same queue
 
-As mentioned above, sometimes we may want to have multiple instances of the same command running at the same time. The queue is safe to use in that scenario with all databases except `SQLite3` since it doesn't guarantee that the job will be selected only by one process.
+As mentioned above, sometimes we may want to have multiple instances of the same command running at the same time. The queue is safe to use in that scenario with all databases if you keep the `skipLocked` to `true` in the config file. Only for SQLite3 driver this setting is not relevant.
 
 ### Handling long-running process
 

src/Config/Queue.php

@@ -45,6 +45,9 @@ class Queue extends BaseConfig
     public array $database = [
         'dbGroup'   => 'default',
         'getShared' => true,
+        // use skip locked feature to maintain concurrency calls
+        // this is not relevant for the SQLite3 database driver
+        'skipLocked' => true,
     ];
 
     /**

src/Models/QueueJobModel.php

@@ -90,7 +90,7 @@ public function getFromQueue(string $name, array $priority): ?QueueJob
      */
     private function skipLocked(string $sql): string
     {
-        if ($this->db->DBDriver === 'SQLite3') {
+        if ($this->db->DBDriver === 'SQLite3' || config('Queue')->database['skipLocked'] === false) {
             return $sql;
         }
 

tests/Models/QueueJobModelTest.php

@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter Queue.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Tests\Models;
+
+use CodeIgniter\Queue\Models\QueueJobModel;
+use CodeIgniter\Test\ReflectionHelper;
+use Tests\Support\TestCase;
+
+/**
+ * @internal
+ */
+final class QueueJobModelTest extends TestCase
+{
+    use ReflectionHelper;
+
+    public function testQueueJobModel(): void
+    {
+        $model = model(QueueJobModel::class);
+        $this->assertInstanceOf(QueueJobModel::class, $model);
+    }
+
+    public function testSkipLocked(): void
+    {
+        $model  = model(QueueJobModel::class);
+        $method = $this->getPrivateMethodInvoker($model, 'skipLocked');
+
+        $sql    = 'SELECT * FROM queue_jobs WHERE queue = "test" AND status = 0 AND available_at < 123456 LIMIT 1';
+        $result = $method($sql);
+
+        if ($model->db->DBDriver === 'SQLite3') {
+            $this->assertSame($sql, $result);
+        } elseif ($model->db->DBDriver === 'SQLSRV') {
+            $expected = 'SELECT * FROM queue_jobs WITH (ROWLOCK,UPDLOCK,READPAST) WHERE queue = "test" AND status = 0 AND available_at < 123456 LIMIT 1';
+            $this->assertSame($expected, $result);
+        } else {
+            $expected = 'SELECT * FROM queue_jobs WHERE queue = "test" AND status = 0 AND available_at < 123456 LIMIT 1 FOR UPDATE SKIP LOCKED';
+            $this->assertSame($expected, $result);
+        }
+    }
+
+    public function testSkipLockedFalse(): void
+    {
+        config('Queue')->database['skipLocked'] = false;
+
+        $model  = model(QueueJobModel::class);
+        $method = $this->getPrivateMethodInvoker($model, 'skipLocked');
+
+        $sql    = 'SELECT * FROM queue_jobs WHERE queue = "test" AND status = 0 AND available_at < 123456 LIMIT 1';
+        $result = $method($sql);
+
+        $this->assertSame($sql, $result);
+    }
+}

tests/_support/Config/Queue.php

@@ -40,8 +40,9 @@ class Queue extends BaseQueue
      * Database handler config.
      */
     public array $database = [
-        'dbGroup'   => 'default',
-        'getShared' => true,
+        'dbGroup'    => 'default',
+        'getShared'  => true,
+        'skipLocked' => true,
     ];
 
     /**