php想要实现mqtt需要使用到php中的socket函数;
此次使用的是网上开源mqtt案例:其中使用的是 stream_socket_xxxx 系列函数
大概意思是:
正如你所指出的，'stream'是PHP核心（内置的，始终可用），而'套接字'是很少包含的扩展的一部分。除此之外，它们几乎完全相同。您可以同时使用TCP和UDP两种流，也可以使用阻塞和非阻塞模式，这些模式涵盖了所有用例的99％。
我能想到的唯一常见的例外是ICMP。例如，'ping'。但是，看起来目前还没有一种安全的方式来从PHP执行ICMP。这种调用需要通过套接字扩展来实现SOCK_RAW，这需要执行“root”权限。此外，并非所有路由器都会在TCP，UDP和ICMP之外路由其他数据包类型。这限制了套接字扩展的实用性。
MQTT类代码:
/* phpMQTT */class Mqtt {
private $socket; /* holds the socket */
private $msgid = 1; /* counter for message id */
public $keepalive = 10; /* default keepalive timmer */
public $timesinceping; /* host unix time, used to detect disconects */
public $topics = array(); /* used to store currently subscribed topics */
public $debug = false; /* should output debug messages */
public $address; /* broker address */
public $port; /* broker port */
public $clientid; /* client id sent to brocker */
public $will; /* stores the will of the client */
private $username; /* stores username */
private $password; /* stores password */
public $cafile;
function __construct($address, $port, $clientid, $cafile = NULL){
$this->broker($address, $port, $clientid, $cafile);
}
/* sets the broker details */
function broker($address, $port, $clientid, $cafile = NULL){
$this->address = $address;
$this->port = $port;
$this->clientid = $clientid;
$this->cafile = $cafile;
}
function connect_auto($clean = true, $will = NULL, $username = NULL, $password = NULL){
while($this->connect($clean, $will, $username, $password)==false){
sleep(10);
}
return true;
}
/* connects to the broker
inputs: $clean: should the client send a clean session flag */
function connect($clean = true, $will = NULL, $username = NULL, $password = NULL){
if($will) $this->will = $will;
if($username) $this->username = $username;
if($password) $this->password = $password;
if ($this->cafile) {
$socketContext = stream_context_create(["ssl" => [
"verify_peer_name" => true,
"cafile" => $this->cafile ]]);
$this->socket = stream_socket_client("tls://" . $this->address . ":" . $this->port, $errno, $errstr, 60, STREAM_CLIENT_CONNECT, $socketContext);
} else {
$this->socket = stream_socket_client("tcp://" . $this->address . ":" . $this->port, $errno, $errstr, 60, STREAM_CLIENT_CONNECT);
}
if (!$this->socket ) {
if($this->debug) error_log("stream_socket_create() $errno, $errstr \n");
return false;
}
stream_set_timeout($this->socket, 5);
stream_set_blocking($this->socket, 0);
$i = 0;
$buffer = "";
$buffer .= chr(0x00); $i++;
$buffer .= chr(0x06); $i++;
$buffer .= chr(0x4d); $i++;
$buffer .= chr(0x51); $i++;
$buffer .= chr(0x49); $i++;
$buffer .= chr(0x73); $i++;
$buffer .= chr(0x64); $i++;
$buffer .= chr(0x70); $i++;
$buffer .= chr(0x03); $i++;
//No Will
$var = 0;
if($clean) $var+=2;
//Add will info to header
if($this->will != NULL){
$var += 4; // Set will flag
$var += ($this->will['qos'] << 3); //Set will qos
if($this->will['retain']) $var += 32; //Set will retain
}
if($this->username != NULL) $var += 128; //Add username to header
if($this->password != NULL) $var += 64; //Add password to header
$buffer .= chr($var); $i++;
//Keep alive
$buffer .= chr($this->keepalive >> 8); $i++;
$buffer .= chr($this->keepalive & 0xff); $i++;
$buffer .= $this->strwritestring($this->clientid,$i);
//Adding will to payload
if($this->will != NULL){
$buffer .= $this->strwritestring($this->will['topic'],$i);
$buffer .= $this->strwritestring($this->will['content'],$i);
}
if($this->username) $buffer .= $this->strwritestring($this->username,$i);
if($this->password) $buffer .= $this->strwritestring($this->password,$i);
$head = " ";
$head{0} = chr(0x10);
$head{1} = chr($i);
fwrite($this->socket, $head, 2);
fwrite($this->socket, $buffer);
$string = $this->read(4);
if(ord($string{0})>>4 == 2 && $string{3} == chr(0)){
if($this->debug) echo "Connected to Broker\n";
}else{
error_log(sprintf("Connection failed! (Error: 0x%02x 0x%02x)\n",
ord($string{0}),ord($string{3})));
return false;
}
$this->timesinceping = time();
return true;
}
/* read: reads in so many bytes */
function read($int = 8192, $nb = false){
// print_r(socket_get_status($this->socket));
$string="";
$togo = $int;
if($nb){
return fread($this->socket, $togo);
}
while (!feof($this->socket) && $togo>0) {
$fread = fread($this->socket, $togo);
$string .= $fread;
$togo = $int - strlen($string);
}
return $string;
}
/* subscribe: subscribes to topics */
function subscribe($topics, $qos = 0){
$i = 0;
$buffer = "";
$id = $this->msgid;
$buffer .= chr($id >> 8); $i++;
$buffer .= chr($id % 256); $i++;
foreach($topics as $key => $topic){
$buffer .= $this->strwritestring($key,$i);
$buffer .= chr($topic["qos"]); $i++;
$this->topics[$key] = $topic;
}
$cmd = 0x80;
//$qos
$cmd += ($qos << 1);
$head = chr($cmd);
$head .= chr($i);
fwrite($this->socket, $head, 2);
fwrite($this->socket, $buffer, $i);
$string = $this->read(2);
$bytes = ord(substr($string,1,1));
$string = $this->read($bytes);
}
/* ping: sends a keep alive ping */
function ping(){
$head = " ";
$head = chr(0xc0);
$head .= chr(0x00);
fwrite($this->socket, $head, 2);
if($this->debug) echo "ping sent\n";
}
/* disconnect: sends a proper disconect cmd */
function disconnect(){
$head = " ";
$head{0} = chr(0xe0);
$head{1} = chr(0x00);
fwrite($this->socket, $head, 2);
}
/* close: sends a proper disconect, then closes the socket */
function close(){
$this->disconnect();
stream_socket_shutdown($this->socket, STREAM_SHUT_WR);
}
/* publish: publishes $content on a $topic */
function publish($topic, $content, $qos = 0, $retain = 0){
$i = 0;
$buffer = "";
$buffer .= $this->strwritestring($topic,$i);
//$buffer .= $this->strwritestring($content,$i);
if($qos){
$id = $this->msgid++;
$buffer .= chr($id >> 8); $i++;
$buffer .= chr($id % 256); $i++;
}
$buffer .= $content;
$i+=strlen($content);
$head = " ";
$cmd = 0x30;
if($qos) $cmd += $qos << 1;
if($retain) $cmd += 1;
$head{0} = chr($cmd);
$head .= $this->setmsglength($i);
fwrite($this->socket, $head, strlen($head));
fwrite($this->socket, $buffer, $i);
}
/* message: processes a recieved topic */
function message($msg){
$tlen = (ord($msg{0})<<8) + ord($msg{1});
$topic = substr($msg,2,$tlen);
$msg = substr($msg,($tlen+2));
$found = 0;
foreach($this->topics as $key=>$top){
if( preg_match("/^".str_replace("#",".*",
str_replace("+","[^\/]*",
str_replace("/","\/",
str_replace("$",'\$',
$key))))."$/",$topic) ){
if(is_callable($top['function'])){
call_user_func($top['function'],$topic,$msg);
$found = 1;
}
}
}
if($this->debug && !$found) echo "msg recieved but no match in subscriptions\n";
}
/* proc: the processing loop for an "allways on" client
set true when you are doing other stuff in the loop good for watching something else at the same time */
function proc( $loop = true){
if(1){
$sockets = array($this->socket);
$w = $e = NULL;
$cmd = 0;
//$byte = fgetc($this->socket);
if(feof($this->socket)){
if($this->debug) echo "eof receive going to reconnect for good measure\n";
fclose($this->socket);
$this->connect_auto(false);
if(count($this->topics))
$this->subscribe($this->topics);
}
$byte = $this->read(1, true);
if(!strlen($byte)){
if($loop){
usleep(100000);
}
}else{
$cmd = (int)(ord($byte)/16);
if($this->debug) echo "Recevid: $cmd\n";
$multiplier = 1;
$value = 0;
do{
$digit = ord($this->read(1));
$value += ($digit & 127) * $multiplier;
$multiplier *= 128;
}while (($digit & 128) != 0);
if($this->debug) echo "Fetching: $value\n";
if($value)
$string = $this->read($value);
if($cmd){
switch($cmd){
case 3:
$this->message($string);
break;
}
$this->timesinceping = time();
}
}
if($this->timesinceping < (time() - $this->keepalive )){
if($this->debug) echo "not found something so ping\n";
$this->ping();
}
if($this->timesinceping<(time()-($this->keepalive*2))){
if($this->debug) echo "not seen a package in a while, disconnecting\n";
fclose($this->socket);
$this->connect_auto(false);
if(count($this->topics))
$this->subscribe($this->topics);
}
}
return 1;
}
/* getmsglength: */
function getmsglength(&$msg, &$i){
$multiplier = 1;
$value = 0 ;
do{
$digit = ord($msg{$i});
$value += ($digit & 127) * $multiplier;
$multiplier *= 128;
$i++;
}while (($digit & 128) != 0);
return $value;
}
/* setmsglength: */
function setmsglength($len){
$string = "";
do{
$digit = $len % 128;
$len = $len >> 7;
// if there are more digits to encode, set the top bit of this digit
if ( $len > 0 )
$digit = ($digit | 0x80);
$string .= chr($digit);
}while ( $len > 0 );
return $string;
}
/* strwritestring: writes a string to a buffer */
function strwritestring($str, &$i){
$ret = " ";
$len = strlen($str);
$msb = $len >> 8;
$lsb = $len % 256;
$ret = chr($msb);
$ret .= chr($lsb);
$ret .= $str;
$i += ($len+2);
return $ret;
}
function printstr($string){
$strlen = strlen($string);
for($j=0;$j<$strlen;$j++){
$num = ord($string{$j});
if($num > 31)
$chr = $string{$j}; else $chr = " ";
printf("%4d: %08b : 0x%02x : %s \n",$j,$num,$num,$chr);
}
}}实现部分
发送到主题
// 发送给订阅号信息,创建socket,无sam队列
$server = "127.0.0.1"; // 服务代理地址(mqtt服务端地址)
$port = 1883; // 通信端口
$username = ""; // 用户名(如果需要)
$password = ""; // 密码(如果需要
$client_id = "clientx9293670xxctr"; // 设置你的连接客户端id
$mqtt = new Mqtt($server, $port, $client_id); //实例化MQTT类
if ($mqtt->connect(true, NULL, $username, $password)) {
//如果创建链接成功
$mqtt->publish("xxx3809293670ctr", "setr=3xxxxxxxxx", 0);
// 发送到 xxx3809293670ctr 的主题 一个信息 内容为 setr=3xxxxxxxxx Qos 为 0
$mqtt->close(); //发送后关闭链接
} else {
echo "Time out!\n";
}订阅主题
/*// 订阅信息,接收一个信息后退出
$server = "127.0.0.1"; // 服务代理地址(mqtt服务端地址)
$port = 1883; // 通信端口
$username = ""; // 用户名(如果需要)
$password = ""; // 密码(如果需要
$client_id = "clientx9293670xxctr"; // 设置你的连接客户端id
$mqtt = new Mqtt($server, $port, $client_id);
if(!$mqtt->connect(true, NULL, $username, $password)) { //链接不成功再重复执行监听连接
exit(1);
}
$topics['SN69143809293670state'] = array("qos" => 0, "function" => "procmsg");
// 订阅主题为 SN69143809293670state qos为0
$mqtt->subscribe($topics, 0);
while($mqtt->proc()){
}
//死循环监听
$mqtt->close();
function procmsg($topic, $msg){ //信息回调函数 打印信息
echo "Msg Recieved: " . date("r") . "\n";
echo "Topic: {$topic}\n\n";
echo "\t$msg\n\n";
$xxx = json_decode($msg);
var_dump($xxxxxx->aa);
die;
}转发自phpMQTT详解以及处理使用过程中内存耗死问题 · php开发笔记 · 看云 (kancloud.cn)
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