include/hw/stream.h

   1 #ifndef STREAM_H
   2 #define STREAM_H
   3
   4 #include "qom/object.h"
   5
   6 #define TYPE_STREAM_SINK "stream-sink"
   7
   8 typedef struct StreamSinkClass StreamSinkClass;
   9 DECLARE_CLASS_CHECKERS(StreamSinkClass, STREAM_SINK,
  10                        TYPE_STREAM_SINK)
  11 #define STREAM_SINK(obj) \
  12      INTERFACE_CHECK(StreamSink, (obj), TYPE_STREAM_SINK)
  13
  14 typedef struct StreamSink StreamSink;
  15
  16 typedef void (*StreamCanPushNotifyFn)(void *opaque);
  17
  18 struct StreamSinkClass {
  19     InterfaceClass parent;
  20     /**
  21      * can push - determine if a stream sink is capable of accepting at least
  22      * one byte of data. Returns false if cannot accept. If not implemented, the
  23      * sink is assumed to always be capable of receiving.
  24      * @notify: Optional callback that the sink will call when the sink is
  25      * capable of receiving again. Only called if false is returned.
  26      * @notify_opaque: opaque data to pass to notify call.
  27      */
  28     bool (*can_push)(StreamSink *obj, StreamCanPushNotifyFn notify,
  29                      void *notify_opaque);
  30     /**
  31      * push - push data to a Stream sink. The number of bytes pushed is
  32      * returned. If the sink short returns, the master must wait before trying
  33      * again, the sink may continue to just return 0 waiting for the vm time to
  34      * advance. The can_push() function can be used to trap the point in time
  35      * where the sink is ready to receive again, otherwise polling on a QEMU
  36      * timer will work.
  37      * @obj: Stream sink to push to
  38      * @buf: Data to write
  39      * @len: Maximum number of bytes to write
  40      * @eop: End of packet flag
  41      */
  42     size_t (*push)(StreamSink *obj, unsigned char *buf, size_t len, bool eop);
  43 };
  44
  45 size_t
  46 stream_push(StreamSink *sink, uint8_t *buf, size_t len, bool eop);
  47
  48 bool
  49 stream_can_push(StreamSink *sink, StreamCanPushNotifyFn notify,
  50                 void *notify_opaque);
  51
  52
  53 #endif /* STREAM_H */