141 lines
3.3 KiB
PHP
141 lines
3.3 KiB
PHP
<?php
|
|
|
|
namespace Workerman\Mqtt\Handle;
|
|
|
|
use Workerman\Mqtt\Consts\MQTTConst;
|
|
|
|
class Decoder
|
|
{
|
|
/**
|
|
* Get cmd.
|
|
*
|
|
* @param string $buffer
|
|
* @return int
|
|
*/
|
|
public static function getCmd(string $buffer)
|
|
{
|
|
return ord($buffer[0]) >> 4;
|
|
}
|
|
|
|
/**
|
|
* Read string from buffer.
|
|
* @param string $buffer
|
|
* @return string
|
|
*/
|
|
public static function readString(string &$buffer)
|
|
{
|
|
$length = unpack('n', $buffer)[1];
|
|
if ($length + 2 > strlen($buffer)) {
|
|
echo "buffer:" . bin2hex($buffer) . " length:$length not enough for unpackString\n";
|
|
}
|
|
|
|
$string = substr($buffer, 2, $length);
|
|
$buffer = substr($buffer, $length + 2);
|
|
return $string;
|
|
}
|
|
|
|
/**
|
|
* Read unsigned short int from buffer.
|
|
* @param string $buffer
|
|
* @return mixed
|
|
*/
|
|
public static function shortInt(string &$buffer)
|
|
{
|
|
$tmp = unpack('n', $buffer);
|
|
$buffer = substr($buffer, 2);
|
|
|
|
return $tmp[1];
|
|
}
|
|
|
|
public static function longInt(string &$buffer)
|
|
{
|
|
$tmp = unpack('N', $buffer);
|
|
$buffer = substr($buffer, 4);
|
|
|
|
return $tmp[1];
|
|
}
|
|
|
|
public static function byte(string &$buffer)
|
|
{
|
|
$tmp = ord($buffer[0]);
|
|
$buffer = substr($buffer, 1);
|
|
|
|
return $tmp;
|
|
}
|
|
|
|
public static function varInt(string&$remaining, &$len)
|
|
{
|
|
$body_length = static::getBodyLength($remaining, $head_bytes);
|
|
$len = $head_bytes;
|
|
|
|
$result = $shift = 0;
|
|
for ($i = 0; $i < $len; $i++) {
|
|
$byte = ord($remaining[$i]);
|
|
$result |= ($byte & 0x7F) << $shift++ * 7;
|
|
}
|
|
|
|
$remaining = substr($remaining, $head_bytes, $body_length);
|
|
|
|
return $result;
|
|
}
|
|
|
|
/**
|
|
* Get body length.
|
|
*
|
|
* @param string $buffer
|
|
* @param null|int $head_bytes
|
|
* @return int
|
|
*/
|
|
public static function getBodyLength(string $buffer, &$head_bytes)
|
|
{
|
|
$head_bytes = $multiplier = 1;
|
|
$value = 0;
|
|
do {
|
|
if (!isset($buffer[$head_bytes])) {
|
|
throw new \Exception('Malformed Remaining Length');
|
|
// $head_bytes = 0;
|
|
// return 0;
|
|
}
|
|
$digit = ord($buffer[$head_bytes]);
|
|
$value += ($digit & 127) * $multiplier;
|
|
$multiplier *= 128;
|
|
++$head_bytes;
|
|
} while (($digit & 128) != 0);
|
|
|
|
return $value;
|
|
}
|
|
|
|
/**
|
|
* Get body.
|
|
*
|
|
* @param string $buffer
|
|
* @return string
|
|
*/
|
|
public static function getBody(string $buffer)
|
|
{
|
|
$body_length = static::getBodyLength($buffer, $head_bytes);
|
|
return substr($buffer, $head_bytes, $body_length);
|
|
}
|
|
|
|
/**
|
|
* Get the MQTT protocol level.
|
|
*
|
|
* @param string $data
|
|
* @return int
|
|
*/
|
|
public static function getLevel(string $data)
|
|
{
|
|
$cmd = static::getCmd($data);
|
|
|
|
if ($cmd !== MQTTConst::CMD_CONNECT) {
|
|
throw new \InvalidArgumentException(
|
|
sprintf('packet must be of type connect, cmd value equal %s given', $cmd)
|
|
);
|
|
}
|
|
|
|
$remaining = static::getBody($data);
|
|
$length = unpack('n', $remaining)[1];
|
|
|
|
return ord($remaining[$length + 2]);
|
|
}
|
|
} |