////  ControlPacket.cpp//  libraries/networking/src/udt////  Created by Stephen Birarda on 2015-07-24.//  Copyright 2015 High Fidelity, Inc.//  Copyright 2021 Vircadia contributors.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #include "ControlPacket.h" #include "Constants.h" using namespace udt; int ControlPacket::localHeaderSize() {    return sizeof(ControlPacket::ControlBitAndType);}int ControlPacket::totalHeaderSize() {    return BasePacket::totalHeaderSize() + ControlPacket::localHeaderSize();}int ControlPacket::maxPayloadSize() {    return BasePacket::maxPayloadSize() - ControlPacket::localHeaderSize();} std::unique_ptr<ControlPacket> ControlPacket::fromReceivedPacket(std::unique_ptr<char[]> data, qint64 size,                                                                 const SockAddr &senderSockAddr) {    // Fail with null data    Q_ASSERT(data);        // Fail with invalid size    Q_ASSERT(size >= 0);        // allocate memory    auto packet = std::unique_ptr<ControlPacket>(new ControlPacket(std::move(data), size, senderSockAddr));        packet->open(QIODevice::ReadOnly);        return packet;} std::unique_ptr<ControlPacket> ControlPacket::create(Type type, qint64 size) {    return std::unique_ptr<ControlPacket>(new ControlPacket(type, size));} ControlPacket::ControlPacket(Type type, qint64 size) :    BasePacket((size == -1) ? -1 : ControlPacket::localHeaderSize() + size),    _type(type){    adjustPayloadStartAndCapacity(ControlPacket::localHeaderSize());        open(QIODevice::ReadWrite);        writeType();} ControlPacket::ControlPacket(std::unique_ptr<char[]> data, qint64 size, const SockAddr& senderSockAddr) :    BasePacket(std::move(data), size, senderSockAddr){    // sanity check before we decrease the payloadSize with the payloadCapacity    Q_ASSERT(_payloadSize == _payloadCapacity);        adjustPayloadStartAndCapacity(ControlPacket::localHeaderSize(), _payloadSize > 0);        readType();} ControlPacket::ControlPacket(ControlPacket&& other) :    BasePacket(std::move(other)){    _type = other._type;} ControlPacket& ControlPacket::operator=(ControlPacket&& other) {    BasePacket::operator=(std::move(other));        _type = other._type;        return *this;} void ControlPacket::setType(udt::ControlPacket::Type type) {    _type = type;        writeType();} void ControlPacket::writeType() {    ControlBitAndType* bitAndType = reinterpret_cast<ControlBitAndType*>(_packet.get());        // We override the control bit here by writing the type but it's okay, it'll always be 1    *bitAndType = CONTROL_BIT_MASK | (ControlBitAndType(_type) << (8 * sizeof(Type)));} void ControlPacket::readType() {    ControlBitAndType bitAndType = *reinterpret_cast<ControlBitAndType*>(_packet.get());        Q_ASSERT_X(bitAndType & CONTROL_BIT_MASK, "ControlPacket::readType()", "This should be a control packet");        uint16_t packetType = (bitAndType & ~CONTROL_BIT_MASK) >> (8 * sizeof(Type));    Q_ASSERT_X(packetType <= ControlPacket::Type::HandshakeRequest, "ControlPacket::readType()",        "Received a control packet with invalid type");        // read the type    _type = (Type) packetType;}