src/kits/media/legacy/OldSubscriber.h

   1 /******************************************************************************
   2
   3         File:                   Subscriber.h
   4
   5         Description:    Support for communication with a buffer stream server
   6
   7         Copyright 1995-97, Be Incorporated
   8
   9 ******************************************************************************/
  10
  11 #ifndef _SUBSCRIBER_H
  12 #define _SUBSCRIBER_H
  13
  14 #include <MediaDefs.h>
  15
  16 #include "OldBufferStream.h"
  17
  18 /* ================
  19    declarations
  20    ================ */
  21
  22 typedef bool (*enter_stream_hook)(void *userData, char *buffer, size_t count,
  23                                                                   void *header);
  24 typedef status_t (*exit_stream_hook)(void *userData, status_t error);
  25
  26 /* ================
  27    Class definition for BSubscriber
  28    ================ */
  29
  30 class BSubscriber
  31 {
  32 public:
  33                                                 BSubscriber(const char *name = NULL);
  34         virtual                         ~BSubscriber();
  35
  36 /* ================
  37    Gaining access to the Buffer Stream
  38    ================ */
  39
  40         virtual status_t        Subscribe(BAbstractBufferStream* stream);
  41         virtual status_t        Unsubscribe();
  42
  43     subscriber_id               ID() const;
  44         const char                      *Name() const;
  45
  46         void                            SetTimeout(bigtime_t microseconds);
  47         bigtime_t                       Timeout() const;
  48
  49 /* ================
  50    Streaming functions.
  51    ================ */
  52
  53         virtual status_t        EnterStream(subscriber_id neighbor,
  54                                                                         bool before,
  55                                                                         void *userData,
  56                                                                         enter_stream_hook entryFunction,
  57                                                                         exit_stream_hook exitFunction,
  58                                                                         bool background);
  59
  60         virtual status_t        ExitStream(bool synch=FALSE);
  61
  62         bool                            IsInStream() const;
  63
  64 /* ================
  65    Protected members (may be used by inherited classes)
  66    ================ */
  67
  68 protected:
  69
  70         static status_t         _ProcessLoop(void *arg);
  71         virtual status_t        ProcessLoop();
  72         BAbstractBufferStream   *Stream() const;
  73
  74 /* ================
  75    Private members
  76    ================ */
  77
  78 private:
  79
  80 virtual void            _ReservedSubscriber1();
  81 virtual void            _ReservedSubscriber2();
  82 virtual void            _ReservedSubscriber3();
  83
  84         char                            *fName;                 /* name given to constructor */
  85         subscriber_id           fSubID;                 /* our subscriber_id */
  86         sem_id                          fSem;                   /* stream semaphore */
  87         BAbstractBufferStream   *fStream;       /* buffer stream */
  88         void                            *fUserData;             /* arg to fStreamFn and fCompletionFn */
  89         enter_stream_hook       fStreamFn;      /* per-buffer user function */
  90         exit_stream_hook        fCompletionFn;  /* called after streaming stops */
  91         bool                            fCallStreamFn;  /* true while we should call fStreamFn */
  92         bigtime_t                       fTimeout;               /* time out while awaiting buffers */
  93         thread_id                       fBackThread;
  94         sem_id                          fSynchLock;
  95
  96         int32                           fFileID;                /* reserved for future use */
  97         uint32                          _reserved[4];
  98 };
  99
 100 #endif  // #ifdef _SUBSCRIBER_H