C++ OTPayload::ReadBytesFrom方法代码示例

// A certain number of bytes are expected in the payload, according to the header.
// This function tries to read that many bytes, and inserts them into an OTPayload object.
// From there, a simple method call extracts the message, we return true, and the message
// gets added to our internal list for processing.
bool OTClientConnection::ProcessType1Cmd(u_header & theCMD, OTMessage & theMessage)
{
	// At this point, the checksum has already validated. 
	// Might as well get the PAYLOAD next.
//	int  err;
	uint32_t nread, lSize = theCMD.fields.size;
	
	// Make sure our byte-order is correct here.
//	theCMD.fields.size = ntohl(theCMD.fields.size); // I was doing this twice!! This is already done when the header is first read.

	// setup the buffer we are reading into
	OTPayload thePayload;
	nread = thePayload.ReadBytesFrom(m_Buffer, lSize);
	
	/*
	// actually read the payload from the socket into the buffer.
	for (nread = 0;  nread < theCMD.fields.size;  nread += err)
	{
		err = SFSocketRead(m_pSocket, 
						   (unsigned char *)thePayload.GetPayloadPointer() + nread,
						   theCMD.fields.size - nread);
		
		// if we don't read anything more, stop reading and move on
		if (err <= 0)
			break;
	}
	*/
	// TODO fix the buffering so that if a complete command has not yet been received, it saves the other
	// bytes instead of discarding them.  For now I'll just sleep for a second to make sure the entire command
	// was received.
//	sleep(1);
	
	// ------------------------------------------------------------
	
	// Try to interpret the command number.
	// Right now we support signed messages and encrypted envelopes containing
	// signed messages.
	switch (theCMD.fields.command_id) {
		case TYPE_1_CMD_1:
			OTLog::Output(2, "Received Type 1 CMD 1:\nThere is a signed OTMessage in the payload.\n");
			break;
		case TYPE_1_CMD_2:
			OTLog::Output(2, "Received Type 1 CMD 2:\n"
					"There is an encrypted OTEnvelope (containing signed OTMessage) in the payload.\n");
			break;
		default:
			OTLog::vError("Received unexpected command number %d in OTClientConnection::ProcessType1Cmd\n", 
					theCMD.fields.command_id);
			break;
	}
	
	// ------------------------------------------------------------
	// Hm, that's weird. It was a 0 size payload message. DoS?
	if (theCMD.fields.size == 0)
	{
		OTLog::Output(2, "(The payload was a 0 size.)\n");
		return true;
	}
	// Uh-oh, somehow the number of bytes read was less than what we expected...
	else if (nread < theCMD.fields.size)
	{
		// TODO: Verify that the amount read matched the amount expected
		// if not, we have a problem that needs to be handled.
		
		// Long term solution is to buffer the data as a comes in and just
		// add it to the buffer.
		
		// Then if we don't have the complete message yet, we just come around next
		// time some data is read, and we add that to the buffer, THEN we check to see
		// if there are enough bytes yet read to match the amount expected according to
		// the header.
		//
		// Until I can do that, I'm not yet TRULY asynchronous. TODO: lookup a good buffer class.

		OTLog::Error("Number of bytes read did NOT match size in header.\n");
		return false;
	}
	else
		OTLog::vOutput(2, "Loaded a payload, size: %d\n", theCMD.fields.size);
	
	// ------------------------------------------------------------
	
	// Okay so now we've received the expected size from the socket. Let's transfer it
	// into an object type that we can manipulate here in code. (Message or Envelope.)
	
	// a signed OTMessage
	if (TYPE_1_CMD_1 == theCMD.fields.command_id) 
	{
#ifdef _WIN32
		if (OTPAYLOAD_GetMessage(thePayload, theMessage))
#else
		if (thePayload.GetMessage(theMessage))
#endif
		{
			OTLog::Output(2, "Successfully retrieved payload message...\n");
			
//.........这里部分代码省略.........