Implemented a simple fifo to decouple from burn_source signals

libburn/file.h

@@ -10,8 +10,45 @@ struct burn_source_file
 	off_t fixed_size;
 };
 
-
 /* ts A70126 : burn_source_file obsoleted burn_source_fd */
 
 
+/* ts A70930 */
+struct burn_source_fifo {
+
+	/* The fifo stays inactive and unequipped with eventual resources
+	   until its read() method is called for the first time.
+	   Only then burn_fifo_start() gets called, allocates the complete
+           resources, starts a thread with burn_fifo_source_shuffler()
+	   which shuffles data and finally destroys the resources.
+	   This late start is to stay modest in case of multiple tracks
+	   in one disc.
+	*/
+	int is_started;
+
+	int thread_pid;
+	int thread_pid_valid;
+
+	/* the burn_source for which this fifo is acting as proxy */
+	struct burn_source *inp;
+
+	/* <<< currently it is only a pipe */
+	int outlet[2];
+
+	/* >>> later it will be a ring buffer mechanism */
+	int chunksize;
+	int chunks;
+	char *buf;
+
+	off_t in_counter;
+	off_t out_counter;
+};
+
+
+/** The worker behind the fifo thread.
+    Gets started from burn_fifo_start() in async.c
+*/
+int burn_fifo_source_shuffler(struct burn_source *source, int flag);
+
+
 #endif /* LIBBURN__FILE_H */