Add option for disabling reads to slaves in replication topologies

turbo124 · turbo124 · commit e132c312a97a · 2023-02-20T20:24:57.000+11:00
diff --git a/src/Replication/ReplicationStrategy.php b/src/Replication/ReplicationStrategy.php
@@ -23,6 +23,7 @@ class ReplicationStrategy
     protected $disallowed;
     protected $readonly;
     protected $readonlySHA1;
+    protected $loadBalancing = true;
 
     public function __construct()
     {
@@ -42,6 +43,10 @@ public function __construct()
      */
     public function isReadOperation(CommandInterface $command)
     {
+        if (!$this->loadBalancing) {
+            return false;
+        }
+
         if (isset($this->disallowed[$id = $command->getId()])) {
             throw new NotSupportedException(
                 "The command '$id' is not allowed in replication mode."
@@ -271,4 +276,18 @@ protected function getReadOnlyOperations()
             'GEORADIUSBYMEMBER' => [$this, 'isGeoradiusReadOnly'],
         ];
     }
+
+    /**
+     * Disables reads to slaves when using
+     * a replication topology.
+     *
+     * @return self
+     */
+    public function disableLoadBalancing(): self
+    {
+        $this->loadBalancing = false;
+
+        return $this;
+    }
+
 }
diff --git a/tests/Predis/Replication/ReplicationStrategyTest.php b/tests/Predis/Replication/ReplicationStrategyTest.php
@@ -18,6 +18,29 @@
 
 class ReplicationStrategyTest extends PredisTestCase
 {
+    /**
+     * @group disconnected
+     */
+    public function testLoadBalancing(): void
+    {
+        $commands = $this->getCommandFactory();
+        $strategy = new ReplicationStrategy();
+
+        $command = $commands->create('GET', ['key']);
+
+        $this->assertTrue(
+            $strategy->isReadOperation($command),
+            'GET is expected to be a read operation.'
+        );
+
+        $strategy->disableLoadBalancing();
+
+        $this->assertFalse(
+            $strategy->isReadOperation($command),
+            'GET is expected to be a write operation.'
+        );
+    }
+
     /**
      * @group disconnected
      */
