1 files changed, 57 insertions, 0 deletions
diff --git a/src/include/hw/stream.h b/src/include/hw/stream.h
new file mode 100644
index 0000000..30ccc56
--- /dev/null
+++ b/src/include/hw/stream.h
@@ -0,0 +1,57 @@
+#ifndef STREAM_H
+#define STREAM_H 1
+
+#include "qemu-common.h"
+#include "qom/object.h"
+
+/* stream slave. Used until qdev provides a generic way.  */
+#define TYPE_STREAM_SLAVE "stream-slave"
+
+#define STREAM_SLAVE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(StreamSlaveClass, (klass), TYPE_STREAM_SLAVE)
+#define STREAM_SLAVE_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(StreamSlaveClass, (obj), TYPE_STREAM_SLAVE)
+#define STREAM_SLAVE(obj) \
+     INTERFACE_CHECK(StreamSlave, (obj), TYPE_STREAM_SLAVE)
+
+typedef struct StreamSlave {
+    Object Parent;
+} StreamSlave;
+
+typedef void (*StreamCanPushNotifyFn)(void *opaque);
+
+typedef struct StreamSlaveClass {
+    InterfaceClass parent;
+    /**
+     * can push - determine if a stream slave is capable of accepting at least
+     * one byte of data. Returns false if cannot accept. If not implemented, the
+     * slave is assumed to always be capable of receiving.
+     * @notify: Optional callback that the slave will call when the slave is
+     * capable of receiving again. Only called if false is returned.
+     * @notify_opaque: opaque data to pass to notify call.
+     */
+    bool (*can_push)(StreamSlave *obj, StreamCanPushNotifyFn notify,
+                     void *notify_opaque);
+    /**
+     * push - push data to a Stream slave. The number of bytes pushed is
+     * returned. If the slave short returns, the master must wait before trying
+     * again, the slave may continue to just return 0 waiting for the vm time to
+     * advance. The can_push() function can be used to trap the point in time
+     * where the slave is ready to receive again, otherwise polling on a QEMU
+     * timer will work.
+     * @obj: Stream slave to push to
+     * @buf: Data to write
+     * @len: Maximum number of bytes to write
+     */
+    size_t (*push)(StreamSlave *obj, unsigned char *buf, size_t len);
+} StreamSlaveClass;
+
+size_t
+stream_push(StreamSlave *sink, uint8_t *buf, size_t len);
+
+bool
+stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
+                void *notify_opaque);
+
+
+#endif /* STREAM_H */