netxReceiveDatagram function net
Receive a new packet that a remote system sent to a datagram socket.
Datagram sockets send packets of data. They either arrive as complete packets or they don't arrive at all, so you'll never receive half a packet.
This call never blocks; if no new data is available at the time of the call, it returns true immediately. The caller can try again later.
On a successful call to this function, it returns true, even if no new
packets are available, so you should check for a successful return and a
non-NULL value in *dgram to decide if a new packet is available.
You must pass received packets to NET_DestroyDatagram when you are done with them. If you want to save the sender's address past this time, it is safe to call NET_RefAddress() on the address and hold onto the pointer, so long as you call NET_UnrefAddress() on it when you are done with it.
Since datagrams can arrive from any address or port on the network without prior warning, this information is available in the NET_Datagram object that is provided by this function, and this is the only way to know who to reply to. Even if you aren't acting as a "server," packets can still arrive at your socket if someone sends one.
If there's a fatal error, this function will return false. Datagram sockets generally won't report failures, because there is no state like a "connection" to fail at this level, but may report failure for unrecoverable system-level conditions; once a datagram socket fails, you should assume it is no longer usable and should destroy it with SDL_DestroyDatagramSocket().
\param sock the datagram socket to send data through. \param dgram a pointer to the datagram packet pointer. \returns true if data sent or queued for transmission, false on failure; call SDL_GetError() for details.
\threadsafety You should not operate on the same socket from multiple threads at the same time without supplying a serialization mechanism. However, different threads may access different sockets at the same time without problems.
\since This function is available since SDL_net 3.0.0.
\sa NET_SendDatagram \sa NET_DestroyDatagram
extern SDL_DECLSPEC bool SDLCALL NET_ReceiveDatagram(NET_DatagramSocket *sock, NET_Datagram **dgram)
Implementation
NetxDatagram? netxReceiveDatagram(
Pointer<NetDatagramSocket> sock, {
bool refAddress = true,
}) {
NetxDatagram? result;
final dgramPointer = ffi.calloc<Pointer<NetDatagram>>();
final bl = netReceiveDatagram(sock, dgramPointer);
if (bl) {
result = NetxDatagram()
..loadFromPointer(dgramPointer.value, refAddress: refAddress);
netDestroyDatagram(dgramPointer.value);
}
dgramPointer.callocFree();
return result;
}