LXR qemu/include/hw/stream.h

   1#ifndef STREAM_H
   2#define STREAM_H
   3
   4#include "qom/object.h"
   5
   6/* stream slave. Used until qdev provides a generic way.  */
   7#define TYPE_STREAM_SLAVE "stream-slave"
   8
   9#define STREAM_SLAVE_CLASS(klass) \
  10     OBJECT_CLASS_CHECK(StreamSlaveClass, (klass), TYPE_STREAM_SLAVE)
  11#define STREAM_SLAVE_GET_CLASS(obj) \
  12    OBJECT_GET_CLASS(StreamSlaveClass, (obj), TYPE_STREAM_SLAVE)
  13#define STREAM_SLAVE(obj) \
  14     INTERFACE_CHECK(StreamSlave, (obj), TYPE_STREAM_SLAVE)
  15
  16typedef struct StreamSlave StreamSlave;
  17
  18typedef void (*StreamCanPushNotifyFn)(void *opaque);
  19
  20typedef struct StreamSlaveClass {
  21    InterfaceClass parent;
  22    /**
  23     * can push - determine if a stream slave is capable of accepting at least
  24     * one byte of data. Returns false if cannot accept. If not implemented, the
  25     * slave is assumed to always be capable of receiving.
  26     * @notify: Optional callback that the slave will call when the slave is
  27     * capable of receiving again. Only called if false is returned.
  28     * @notify_opaque: opaque data to pass to notify call.
  29     */
  30    bool (*can_push)(StreamSlave *obj, StreamCanPushNotifyFn notify,
  31                     void *notify_opaque);
  32    /**
  33     * push - push data to a Stream slave. The number of bytes pushed is
  34     * returned. If the slave short returns, the master must wait before trying
  35     * again, the slave may continue to just return 0 waiting for the vm time to
  36     * advance. The can_push() function can be used to trap the point in time
  37     * where the slave is ready to receive again, otherwise polling on a QEMU
  38     * timer will work.
  39     * @obj: Stream slave to push to
  40     * @buf: Data to write
  41     * @len: Maximum number of bytes to write
  42     */
  43    size_t (*push)(StreamSlave *obj, unsigned char *buf, size_t len);
  44} StreamSlaveClass;
  45
  46size_t
  47stream_push(StreamSlave *sink, uint8_t *buf, size_t len);
  48
  49bool
  50stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
  51                void *notify_opaque);
  52
  53
  54#endif /* STREAM_H */
  55