Files
PhotonVision/photon-lib/src/main/native/include/photonlib/Packet.h
Sriman Achanta c148331b69 Bump License year to 2023 (#841)
* Bump version

* remove year entirely
2023-04-18 18:49:40 -04:00

131 lines
3.7 KiB
C++

/*
* MIT License
*
* Copyright (c) PhotonVision
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#pragma once
#include <algorithm>
#include <string>
#include <vector>
#include <wpi/Endian.h>
namespace photonlib {
/**
* A packet that holds byte-packed data to be sent over NetworkTables.
*/
class Packet {
public:
/**
* Constructs an empty packet.
*/
Packet() = default;
/**
* Constructs a packet with the given data.
* @param data The packet data.
*/
explicit Packet(std::vector<uint8_t> data) : packetData(data) {}
/**
* Clears the packet and resets the read and write positions.
*/
void Clear() {
packetData.clear();
readPos = 0;
writePos = 0;
}
/**
* Returns the packet data.
* @return The packet data.
*/
const std::vector<uint8_t>& GetData() { return packetData; }
/**
* Returns the number of bytes in the data.
* @return The number of bytes in the data.
*/
size_t GetDataSize() const { return packetData.size(); }
/**
* Adds a value to the data buffer. This should only be used with PODs.
* @tparam T The data type.
* @param src The data source.
* @return A reference to the current object.
*/
template <typename T>
Packet& operator<<(T src) {
packetData.resize(packetData.size() + sizeof(T));
std::memcpy(packetData.data() + writePos, &src, sizeof(T));
if constexpr (wpi::support::endian::system_endianness() ==
wpi::support::endianness::little) {
// Reverse to big endian for network conventions.
std::reverse(packetData.data() + writePos,
packetData.data() + writePos + sizeof(T));
}
writePos += sizeof(T);
return *this;
}
/**
* Extracts a value to the provided destination.
* @tparam T The type of value to extract.
* @param value The value to extract.
* @return A reference to the current object.
*/
template <typename T>
Packet& operator>>(T& value) {
if (!packetData.empty()) {
std::memcpy(&value, packetData.data() + readPos, sizeof(T));
if constexpr (wpi::support::endian::system_endianness() ==
wpi::support::endianness::little) {
// Reverse to little endian for host.
uint8_t& raw = reinterpret_cast<uint8_t&>(value);
std::reverse(&raw, &raw + sizeof(T));
}
}
readPos += sizeof(T);
return *this;
}
bool operator==(const Packet& right) const {
return packetData == right.packetData;
}
bool operator!=(const Packet& right) const { return !operator==(right); }
private:
// Data stored in the packet
std::vector<uint8_t> packetData;
size_t readPos = 0;
size_t writePos = 0;
};
} // namespace photonlib