raspisms/models/SystemVQueue.php

116 lines
3.2 KiB
PHP

<?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, true, $error_code);
if (!$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;
}
}