haiku/headers/private/app/PortLink.h

//------------------------------------------------------------------------------
//	Copyright (c) 2001-2002, OpenBeOS
//
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//	copy of this software and associated documentation files (the "Software"),
//	to deal in the Software without restriction, including without limitation
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//	Software is furnished to do so, subject to the following conditions:
//
//	The above copyright notice and this permission notice shall be included in
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//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
//	DEALINGS IN THE SOFTWARE.
//
//	File Name:		PortLink.h
//	Author:			DarkWyrm <bpmagic@columbus.rr.com>
//					Pahtz <pahtz@yahoo.com.au>
//	Description:	Class for low-overhead port-based messaging
//  
//------------------------------------------------------------------------------
#ifndef _PORTLINK_H
#define _PORTLINK_H

#include <OS.h>

/*
	Error checking rules: (for if you don't want to check every return code)
	
	Calling EndMessage() is optional, implied by Flush() or StartMessage().

	If you are sending just one message you only need to test Flush() == B_OK

	If you are buffering multiple messages without calling Flush() you must
		check EndMessage() == B_OK, or the last Attach() for each message. Check
		Flush() at the end.

	If you are reading, check the last Read() or ReadString() you perform.

*/

class LinkMsgReader;
class LinkMsgSender;
class BPortLink
{
public:
	BPortLink(port_id send = -1, port_id reply = -1);
	virtual ~BPortLink();

	status_t StartMessage(int32 code);
	void CancelMessage();
	status_t EndMessage();

	status_t Flush(bigtime_t timeout = B_INFINITE_TIMEOUT);
	
	void SetSendPort(port_id port);
	port_id	GetSendPort();
	
	void SetReplyPort(port_id port);
	port_id	GetReplyPort();

	status_t Attach(const void *data, ssize_t size);
	status_t AttachString(const char *string);
	status_t AttachRegion(const BRegion &region);
	status_t AttachShape(BShape &shape);
	template <class Type> status_t Attach(const Type& data)
	{
		return Attach(&data, sizeof(Type));
	}

	status_t GetNextReply(int32 *code, bigtime_t timeout = B_INFINITE_TIMEOUT);
	status_t Read(void *data, ssize_t size);
	status_t ReadString(char **string);
	status_t ReadRegion(BRegion *region);
	status_t ReadShape(BShape *shape);
	template <class T> status_t Read(T *data)
	{
		return Read(data,sizeof(T));
	}
	
protected:
	LinkMsgReader *fReader;
	LinkMsgSender *fSender;
};

#endif