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