Add support for Redis in addition to System V queues

models/SystemVQueue.php

@@ -0,0 +1,115 @@
+<?php
+
+/*
+ * This file is part of RaspiSMS.
+ *
+ * (c) Pierre-Lin Bonnemaison <plebwebsas@gmail.com>
+ *
+ * This source file is subject to the GPL-3.0 license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace models;
+
+/**
+ *
+ */
+class SystemVQueue implements Queue
+{
+    private $id;
+    private $queue;
+
+    /**
+     * A queue using System V message queues to store and exchange messages
+     * routing is based on queue id and message type
+     * 
+     * ** Attention : Instead of string, all ids and tags must be numbers, its the system v queues works, no reliable way arround it**
+     * @param int $id : A unique identifier for the queue, *this must be generated with ftok*
+
+     */
+    public function __construct($id)
+    {
+        $this->id = (int) $id;
+    }
+
+    /**
+     * Function to close the system v queue on destruction
+     */
+    public function close()
+    {
+        if ($this->queue)
+        {
+            msg_remove_queue($this->queue);
+        }
+    }
+
+    /**
+     * Function to get the message queue and ensure it is open, we should always call it during push/read just to 
+     * make sure another process didn't close the queue
+     */
+    private function get_queue()
+    {
+        $this->queue = msg_get_queue($this->id);
+
+        if (!$this->queue)
+        {
+            throw new \Exception('Impossible to get a System V message queue for id ' . $this->id);
+        }
+    }
+
+    /**
+     * Add a message to the queue
+     * 
+     * @param string $message : The message to add to the queue
+     * @param ?string $tag : A tag to associate to the message for routing purposes. 
+     * Though this is a string, we MUST pass a valid number, its the way System V queue works
+     */
+    public function push($message, ?string $tag = '0')
+    {   
+        $tag = (int) $tag;
+        
+        $this->get_queue();
+        $error_code = null;
+        $success = msg_send($this->queue, $tag, $message, true, false, $error_code);
+        if (!$success)
+        {
+            throw new \Exception('Impossible to send the message on system V queue, error code : ' . $error_code);
+        }
+
+        return true;
+    }
+
+    /**
+     * Read the older message in the queue
+     * 
+     * @param ?string $tag : A tag to associate to the message for routing purposes
+     * Though this is a string, we MUST pass a valid number, its the way System V queue works
+     * 
+     * @return mixed $message : The oldest message or null if no message found, can be anything
+     */
+    public function read(?string $tag = '0')
+    {
+        $tag = (int) $tag;
+
+        $msgtype = null;
+        $maxsize = 409600;
+        $message = null;
+
+        // Message type is forged from a prefix concat with the phone ID
+        $error_code = null;
+        $this->get_queue();
+        $success = msg_receive($this->queue, $tag, $msgtype, $maxsize, $message, true, MSG_IPC_NOWAIT, $error_code); //MSG_IPC_NOWAIT == dont wait if no message found
+
+        if (!$success && MSG_ENOMSG !== $error_code)
+        {
+            throw new \Exception('Impossible to read messages on system V queue, error code : ' . $error_code);
+        }
+
+        if (!$message)
+        {
+            return null;
+        }
+
+        return $message;
+    }
+}