/**
* Data decoding, according to related IETF draft
*
* @see http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10#page-16
*/
protected function _dataDecode()
{
//参考 http://blog.csdn.net/fenglibing/article/details/6852497
//这里仅仅处理最基本的
$encodedData =& $this->webSocketSession->buf;
// 至少有2个字节的头
while (($buflen = strlen($encodedData)) >= 2) {
$len = 0;
$isMasked = (bool) (ord($encodedData[1]) >> 7);
$opcode = ord($encodedData[0]) & 15;
$dataLength = ord($encodedData[1]) & 127;
$len += 2;
if ($dataLength === 126) {
$extDataLength = hexdec(sprintf('%02x%02x', ord($encodedData[2]), ord($encodedData[3])));
$len += 2;
} else {
if ($dataLength === 127) {
$extDataLength = hexdec(sprintf('%02x%02x%02x%02x%02x%02x%02x%02x', ord($encodedData[2]), ord($encodedData[3]), ord($encodedData[4]), ord($encodedData[5]), ord($encodedData[6]), ord($encodedData[7]), ord($encodedData[8]), ord($encodedData[9])));
$len += 8;
} else {
$extDataLength = $dataLength;
}
}
if (webSocketSession::maxPacketSize <= $extDataLength) {
// Too big packet
$this->webSocketSession->close();
return;
}
if ($isMasked) {
$maskingKey = Utils::binarySubstr($encodedData, $len, 4);
$len += 4;
}
if ($extDataLength + $len > strlen($encodedData)) {
//没有出现包
// not enough data yet
return;
}
$data = Utils::binarySubstr($encodedData, $len, $extDataLength);
//这里用的引用，所以会处理掉 socketSession->buf
$encodedData = Utils::binarySubstr($encodedData, $len + $extDataLength);
if ($opcode === self::CLOSE) {
//客户端主动关闭连接
$this->webSocketSession->close();
return;
}
if ($opcode === self::PING) {
$this->sendFrame('', 'PONG');
continue;
}
if ($opcode === self::PONG) {
//todo: 收到 pong 包，不做任何事情，以后应该更新最后的连接时间
daemon::log(get_class($this) . '::' . __METHOD__ . ' : receive PONG packet. ' . $this->webSocketSession->addr);
continue;
}
if ($isMasked) {
$unmaskingFunc = function ($data, $mask) {
for ($i = 0, $l = strlen($data); $i < $l; $i++) {
// Avoid storing a new copy of $data...
$data[$i] = $data[$i] ^ $mask[$i % 4];
}
return $data;
};
$this->webSocketSession->onFrame($unmaskingFunc($data, $maskingKey), $opcode);
} else {
$this->webSocketSession->onFrame($data, $opcode);
}
}
}
