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SFML/include/SFML/Network/Packet.hpp
Mario Liebisch a1d4bc80c2 Changed Doxygen single-line comment format 
Single line comments starting with `///` are interpreted by
Microsoft Visual Studio as documentation containing XML code.

Therefore single line comments starting with `///<` unfortunately
cause a parsing error, as IntelliSense will assume the `<` is the
start of an XML tag. This is not the case, but unfortunately,
IntelliSense will still complain about the following space
character rather than displaying the raw string. This commit alters
all such comments to start with `//!<` instead, which prevents the
issue.

This fixes issue #1622.
2020-01-02 15:25:57 +01:00

533 lines
18 KiB
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////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2019 Laurent Gomila (laurent@sfml-dev.org)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
// you must not claim that you wrote the original software.
// If you use this software in a product, an acknowledgment
// in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
// and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////
#ifndef SFML_PACKET_HPP
#define SFML_PACKET_HPP
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Network/Export.hpp>
#include <string>
#include <vector>
namespace sf
{
class String;
class TcpSocket;
class UdpSocket;
////////////////////////////////////////////////////////////
/// \brief Utility class to build blocks of data to transfer
/// over the network
///
////////////////////////////////////////////////////////////
class SFML_NETWORK_API Packet
{
// A bool-like type that cannot be converted to integer or pointer types
typedef bool (Packet::*BoolType)(std::size_t);
public:
////////////////////////////////////////////////////////////
/// \brief Default constructor
///
/// Creates an empty packet.
///
////////////////////////////////////////////////////////////
Packet();
////////////////////////////////////////////////////////////
/// \brief Virtual destructor
///
////////////////////////////////////////////////////////////
virtual ~Packet();
////////////////////////////////////////////////////////////
/// \brief Append data to the end of the packet
///
/// \param data Pointer to the sequence of bytes to append
/// \param sizeInBytes Number of bytes to append
///
/// \see clear
///
////////////////////////////////////////////////////////////
void append(const void* data, std::size_t sizeInBytes);
////////////////////////////////////////////////////////////
/// \brief Clear the packet
///
/// After calling Clear, the packet is empty.
///
/// \see append
///
////////////////////////////////////////////////////////////
void clear();
////////////////////////////////////////////////////////////
/// \brief Get a pointer to the data contained in the packet
///
/// Warning: the returned pointer may become invalid after
/// you append data to the packet, therefore it should never
/// be stored.
/// The return pointer is NULL if the packet is empty.
///
/// \return Pointer to the data
///
/// \see getDataSize
///
////////////////////////////////////////////////////////////
const void* getData() const;
////////////////////////////////////////////////////////////
/// \brief Get the size of the data contained in the packet
///
/// This function returns the number of bytes pointed to by
/// what getData returns.
///
/// \return Data size, in bytes
///
/// \see getData
///
////////////////////////////////////////////////////////////
std::size_t getDataSize() const;
////////////////////////////////////////////////////////////
/// \brief Tell if the reading position has reached the
/// end of the packet
///
/// This function is useful to know if there is some data
/// left to be read, without actually reading it.
///
/// \return True if all data was read, false otherwise
///
/// \see operator bool
///
////////////////////////////////////////////////////////////
bool endOfPacket() const;
public:
////////////////////////////////////////////////////////////
/// \brief Test the validity of the packet, for reading
///
/// This operator allows to test the packet as a boolean
/// variable, to check if a reading operation was successful.
///
/// A packet will be in an invalid state if it has no more
/// data to read.
///
/// This behavior is the same as standard C++ streams.
///
/// Usage example:
/// \code
/// float x;
/// packet >> x;
/// if (packet)
/// {
/// // ok, x was extracted successfully
/// }
///
/// // -- or --
///
/// float x;
/// if (packet >> x)
/// {
/// // ok, x was extracted successfully
/// }
/// \endcode
///
/// Don't focus on the return type, it's equivalent to bool but
/// it disallows unwanted implicit conversions to integer or
/// pointer types.
///
/// \return True if last data extraction from packet was successful
///
/// \see endOfPacket
///
////////////////////////////////////////////////////////////
operator BoolType() const;
////////////////////////////////////////////////////////////
/// Overload of operator >> to read data from the packet
///
////////////////////////////////////////////////////////////
Packet& operator >>(bool& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Int8& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Uint8& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Int16& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Uint16& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Int32& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Uint32& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Int64& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(Uint64& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(float& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(double& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(char* data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(std::string& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(wchar_t* data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(std::wstring& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator >>(String& data);
////////////////////////////////////////////////////////////
/// Overload of operator << to write data into the packet
///
////////////////////////////////////////////////////////////
Packet& operator <<(bool data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Int8 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Uint8 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Int16 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Uint16 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Int32 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Uint32 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Int64 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(Uint64 data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(float data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(double data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(const char* data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(const std::string& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(const wchar_t* data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(const std::wstring& data);
////////////////////////////////////////////////////////////
/// \overload
////////////////////////////////////////////////////////////
Packet& operator <<(const String& data);
protected:
friend class TcpSocket;
friend class UdpSocket;
////////////////////////////////////////////////////////////
/// \brief Called before the packet is sent over the network
///
/// This function can be defined by derived classes to
/// transform the data before it is sent; this can be
/// used for compression, encryption, etc.
/// The function must return a pointer to the modified data,
/// as well as the number of bytes pointed.
/// The default implementation provides the packet's data
/// without transforming it.
///
/// \param size Variable to fill with the size of data to send
///
/// \return Pointer to the array of bytes to send
///
/// \see onReceive
///
////////////////////////////////////////////////////////////
virtual const void* onSend(std::size_t& size);
////////////////////////////////////////////////////////////
/// \brief Called after the packet is received over the network
///
/// This function can be defined by derived classes to
/// transform the data after it is received; this can be
/// used for decompression, decryption, etc.
/// The function receives a pointer to the received data,
/// and must fill the packet with the transformed bytes.
/// The default implementation fills the packet directly
/// without transforming the data.
///
/// \param data Pointer to the received bytes
/// \param size Number of bytes
///
/// \see onSend
///
////////////////////////////////////////////////////////////
virtual void onReceive(const void* data, std::size_t size);
private:
////////////////////////////////////////////////////////////
/// Disallow comparisons between packets
///
////////////////////////////////////////////////////////////
bool operator ==(const Packet& right) const;
bool operator !=(const Packet& right) const;
////////////////////////////////////////////////////////////
/// \brief Check if the packet can extract a given number of bytes
///
/// This function updates accordingly the state of the packet.
///
/// \param size Size to check
///
/// \return True if \a size bytes can be read from the packet
///
////////////////////////////////////////////////////////////
bool checkSize(std::size_t size);
////////////////////////////////////////////////////////////
// Member data
////////////////////////////////////////////////////////////
std::vector<char> m_data; //!< Data stored in the packet
std::size_t m_readPos; //!< Current reading position in the packet
std::size_t m_sendPos; //!< Current send position in the packet (for handling partial sends)
bool m_isValid; //!< Reading state of the packet
};
} // namespace sf
#endif // SFML_PACKET_HPP
////////////////////////////////////////////////////////////
/// \class sf::Packet
/// \ingroup network
///
/// Packets provide a safe and easy way to serialize data,
/// in order to send it over the network using sockets
/// (sf::TcpSocket, sf::UdpSocket).
///
/// Packets solve 2 fundamental problems that arise when
/// transferring data over the network:
/// \li data is interpreted correctly according to the endianness
/// \li the bounds of the packet are preserved (one send == one receive)
///
/// The sf::Packet class provides both input and output modes.
/// It is designed to follow the behavior of standard C++ streams,
/// using operators >> and << to extract and insert data.
///
/// It is recommended to use only fixed-size types (like sf::Int32, etc.),
/// to avoid possible differences between the sender and the receiver.
/// Indeed, the native C++ types may have different sizes on two platforms
/// and your data may be corrupted if that happens.
///
/// Usage example:
/// \code
/// sf::Uint32 x = 24;
/// std::string s = "hello";
/// double d = 5.89;
///
/// // Group the variables to send into a packet
/// sf::Packet packet;
/// packet << x << s << d;
///
/// // Send it over the network (socket is a valid sf::TcpSocket)
/// socket.send(packet);
///
/// -----------------------------------------------------------------
///
/// // Receive the packet at the other end
/// sf::Packet packet;
/// socket.receive(packet);
///
/// // Extract the variables contained in the packet
/// sf::Uint32 x;
/// std::string s;
/// double d;
/// if (packet >> x >> s >> d)
/// {
/// // Data extracted successfully...
/// }
/// \endcode
///
/// Packets have built-in operator >> and << overloads for
/// standard types:
/// \li bool
/// \li fixed-size integer types (sf::Int8/16/32, sf::Uint8/16/32)
/// \li floating point numbers (float, double)
/// \li string types (char*, wchar_t*, std::string, std::wstring, sf::String)
///
/// Like standard streams, it is also possible to define your own
/// overloads of operators >> and << in order to handle your
/// custom types.
///
/// \code
/// struct MyStruct
/// {
/// float number;
/// sf::Int8 integer;
/// std::string str;
/// };
///
/// sf::Packet& operator <<(sf::Packet& packet, const MyStruct& m)
/// {
/// return packet << m.number << m.integer << m.str;
/// }
///
/// sf::Packet& operator >>(sf::Packet& packet, MyStruct& m)
/// {
/// return packet >> m.number >> m.integer >> m.str;
/// }
/// \endcode
///
/// Packets also provide an extra feature that allows to apply
/// custom transformations to the data before it is sent,
/// and after it is received. This is typically used to
/// handle automatic compression or encryption of the data.
/// This is achieved by inheriting from sf::Packet, and overriding
/// the onSend and onReceive functions.
///
/// Here is an example:
/// \code
/// class ZipPacket : public sf::Packet
/// {
/// virtual const void* onSend(std::size_t& size)
/// {
/// const void* srcData = getData();
/// std::size_t srcSize = getDataSize();
///
/// return MySuperZipFunction(srcData, srcSize, &size);
/// }
///
/// virtual void onReceive(const void* data, std::size_t size)
/// {
/// std::size_t dstSize;
/// const void* dstData = MySuperUnzipFunction(data, size, &dstSize);
///
/// append(dstData, dstSize);
/// }
/// };
///
/// // Use like regular packets:
/// ZipPacket packet;
/// packet << x << s << d;
/// ...
/// \endcode
///
/// \see sf::TcpSocket, sf::UdpSocket
///
////////////////////////////////////////////////////////////
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