LXR qemu/include/hw/stream.h

   1#ifndef STREAM_H
   2#define STREAM_H
   3
   4#include "qemu-common.h"
   5#include "qom/object.h"
   6
   7/* stream slave. Used until qdev provides a generic way.  */
   8#define TYPE_STREAM_SLAVE "stream-slave"
   9
  10#define STREAM_SLAVE_CLASS(klass) \
  11     OBJECT_CLASS_CHECK(StreamSlaveClass, (klass), TYPE_STREAM_SLAVE)
  12#define STREAM_SLAVE_GET_CLASS(obj) \
  13    OBJECT_GET_CLASS(StreamSlaveClass, (obj), TYPE_STREAM_SLAVE)
  14#define STREAM_SLAVE(obj) \
  15     INTERFACE_CHECK(StreamSlave, (obj), TYPE_STREAM_SLAVE)
  16
  17typedef struct StreamSlave {
  18    Object Parent;
  19} StreamSlave;
  20
  21typedef void (*StreamCanPushNotifyFn)(void *opaque);
  22
  23typedef struct StreamSlaveClass {
  24    InterfaceClass parent;
  25    /**
  26     * can push - determine if a stream slave is capable of accepting at least
  27     * one byte of data. Returns false if cannot accept. If not implemented, the
  28     * slave is assumed to always be capable of receiving.
  29     * @notify: Optional callback that the slave will call when the slave is
  30     * capable of receiving again. Only called if false is returned.
  31     * @notify_opaque: opaque data to pass to notify call.
  32     */
  33    bool (*can_push)(StreamSlave *obj, StreamCanPushNotifyFn notify,
  34                     void *notify_opaque);
  35    /**
  36     * push - push data to a Stream slave. The number of bytes pushed is
  37     * returned. If the slave short returns, the master must wait before trying
  38     * again, the slave may continue to just return 0 waiting for the vm time to
  39     * advance. The can_push() function can be used to trap the point in time
  40     * where the slave is ready to receive again, otherwise polling on a QEMU
  41     * timer will work.
  42     * @obj: Stream slave to push to
  43     * @buf: Data to write
  44     * @len: Maximum number of bytes to write
  45     */
  46    size_t (*push)(StreamSlave *obj, unsigned char *buf, size_t len);
  47} StreamSlaveClass;
  48
  49size_t
  50stream_push(StreamSlave *sink, uint8_t *buf, size_t len);
  51
  52bool
  53stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
  54                void *notify_opaque);
  55
  56
  57#endif /* STREAM_H */
  58