/******************************************************************************

        File:                   Subscriber.h

        Description:    Support for communication with a buffer stream server

        Copyright 1995-97, Be Incorporated

******************************************************************************/

#ifndef _SUBSCRIBER_H
#define _SUBSCRIBER_H

#include <MediaDefs.h>

#include "OldBufferStream.h"

/* ================
   declarations
   ================ */

typedef bool (*enter_stream_hook)(void *userData, char *buffer, size_t count,
                                                                  void *header);
typedef status_t (*exit_stream_hook)(void *userData, status_t error);

/* ================
   Class definition for BSubscriber
   ================ */

class BSubscriber
{
public:
                                                BSubscriber(const char *name = NULL);
        virtual                         ~BSubscriber();

/* ================
   Gaining access to the Buffer Stream
   ================ */

        virtual status_t        Subscribe(BAbstractBufferStream* stream);
        virtual status_t        Unsubscribe();

    subscriber_id               ID() const;
        const char                      *Name() const;

        void                            SetTimeout(bigtime_t microseconds);
        bigtime_t                       Timeout() const;

/* ================
   Streaming functions.
   ================ */

        virtual status_t        EnterStream(subscriber_id neighbor,
                                                                        bool before,
                                                                        void *userData,
                                                                        enter_stream_hook entryFunction,
                                                                        exit_stream_hook exitFunction,
                                                                        bool background);

        virtual status_t        ExitStream(bool synch=FALSE);

        bool                            IsInStream() const;

/* ================
   Protected members (may be used by inherited classes)
   ================ */

protected:

        static status_t         _ProcessLoop(void *arg);
        virtual status_t        ProcessLoop();
        BAbstractBufferStream   *Stream() const;

/* ================
   Private members
   ================ */

private:

virtual void            _ReservedSubscriber1();
virtual void            _ReservedSubscriber2();
virtual void            _ReservedSubscriber3();

        char                            *fName;                 /* name given to constructor */
        subscriber_id           fSubID;                 /* our subscriber_id */
        sem_id                          fSem;                   /* stream semaphore */
        BAbstractBufferStream   *fStream;       /* buffer stream */
        void                            *fUserData;             /* arg to fStreamFn and fCompletionFn */
        enter_stream_hook       fStreamFn;      /* per-buffer user function */
        exit_stream_hook        fCompletionFn;  /* called after streaming stops */
        bool                            fCallStreamFn;  /* true while we should call fStreamFn */
        bigtime_t                       fTimeout;               /* time out while awaiting buffers */
        thread_id                       fBackThread;
        sem_id                          fSynchLock;

        int32                           fFileID;                /* reserved for future use */
        uint32                          _reserved[4];
};

#endif  // #ifdef _SUBSCRIBER_H