haiku/headers/os/media/TimeSource.h

/*******************************************************************************
/
/	File:			TimeSource.h
/
/   Description:  A BTimeSource is something to which others can slave timing information
/	using the Media Kit.
/
/	Copyright 1997-98, Be Incorporated, All Rights Reserved
/
*******************************************************************************/

#if !defined(_TIME_SOURCE_H)
#define _TIME_SOURCE_H

#include <MediaDefs.h>
#include <MediaNode.h>


class _BSlaveNodeStorageP;

namespace BPrivate { namespace media {
	class BMediaRosterEx;
	class TimeSourceObject;
	class SystemTimeSourceObject;
	class SlaveNodes;
	struct TimeSourceTransmit;
} }


class BTimeSource :
	public virtual BMediaNode
{
protected:
		/* this has to be at the top to force a vtable */
virtual	~BTimeSource();

public:

virtual	status_t SnoozeUntil(				/* returns error if stopped */
				bigtime_t performance_time,
				bigtime_t with_latency = 0,
				bool retry_signals = false);

		bigtime_t Now();	/* convenience, less accurate */
		bigtime_t PerformanceTimeFor(	/* all three go through GetTime() */
				bigtime_t real_time);
		bigtime_t RealTimeFor(
				bigtime_t performance_time,
				bigtime_t with_latency);
		bool IsRunning();

		status_t GetTime(	/* return B_OK if reading is usable */
				bigtime_t * performance_time,
				bigtime_t * real_time,
				float * drift);

static	bigtime_t RealTime();	/* this produces real time, nothing else is guaranteed to */

		status_t GetStartLatency(
				bigtime_t * out_latency);

protected:

		BTimeSource();

virtual	status_t HandleMessage(
				int32 message,
				const void * data,
				size_t size);

		void PublishTime(	/* call this at convenient times to update approximation */
				bigtime_t performance_time,
				bigtime_t real_time,
				float drift);

		void BroadcastTimeWarp(
				bigtime_t at_real_time,
				bigtime_t new_performance_time);	/* when running */
		void SendRunMode(
				run_mode mode);

virtual	void SetRunMode(
				run_mode mode);		/* or, instead, SendRunMode() */

		enum time_source_op {
			B_TIMESOURCE_START = 1,
			B_TIMESOURCE_STOP,
			B_TIMESOURCE_STOP_IMMEDIATELY,
			B_TIMESOURCE_SEEK
		};
		struct time_source_op_info {
			time_source_op op;
			int32 _reserved1;
			bigtime_t real_time;
			bigtime_t performance_time;
			int32 _reserved2[6];
		};
virtual	status_t TimeSourceOp(
				const time_source_op_info & op,
				void * _reserved) = 0;

private:

	friend class BMediaNode;
	friend class BMediaRoster;
	friend class BPrivate::media::BMediaRosterEx;
	friend class BPrivate::media::TimeSourceObject;
	friend class BPrivate::media::SystemTimeSourceObject;

		BTimeSource(		/* private unimplemented */
				const BTimeSource & clone);
		BTimeSource & operator=(
				const BTimeSource & clone);

		/* Mmmh, stuffing! */
			status_t _Reserved_TimeSource_0(void *); // TimeSourceOp()
virtual		status_t _Reserved_TimeSource_1(void *);
virtual		status_t _Reserved_TimeSource_2(void *);
virtual		status_t _Reserved_TimeSource_3(void *);
virtual		status_t _Reserved_TimeSource_4(void *);
virtual		status_t _Reserved_TimeSource_5(void *);

		bool fStarted;
		area_id fArea;
		volatile BPrivate::media::TimeSourceTransmit *fBuf;
		BPrivate::media::SlaveNodes *fSlaveNodes;

		area_id _reserved_area;
		bool fIsRealtime;
		bool _reserved_bool_[3];
		uint32 _reserved_time_source_[10];

explicit	BTimeSource(
				media_node_id id);
		void FinishCreate(); /* called by roster and/or server */

virtual	status_t RemoveMe(BMediaNode * node);
virtual	status_t AddMe(BMediaNode * node);

		void	DirectStart(bigtime_t at);
		void	DirectStop(bigtime_t at, bool immediate);
		void	DirectSeek(bigtime_t to, bigtime_t at);
		void	DirectSetRunMode(run_mode mode);
		void	DirectAddMe(const media_node &node);
		void	DirectRemoveMe(const media_node &node);
};


#endif /* _TIME_SOURCE_H */