Playback: Move internal track list onto buffer

Does away the statically-allocated track list which frees quite
a fair amount of in-RAM size.

There's no compile-time hard track limit.

Recommended TODO (but not right away): Have data small enough use
the handle structure as its buffer data area. Almost the entire
handle structure is unused for simple allocations without any
associated filesystem path.

Change-Id: I74a4561e5a837e049811ac421722ec00dadc0d50

apps/buffering.c

@@ -43,6 +43,8 @@
 /* #define LOGF_ENABLE */
 #include "logf.h"
 
+#define BUF_MAX_HANDLES 384
+
 /* macros to enable logf for queues
    logging on SYS_TIMEOUT can be disabled */
 #ifdef SIMULATOR
@@ -1120,6 +1122,10 @@ bool bufclose(int handle_id)
         return true;
     }
 #endif
+    if (handle_id <= 0) {
+        return true;
+    }
+
     LOGFQUEUE("buffering >| Q_CLOSE_HANDLE %d", handle_id);
     return queue_send(&buffering_queue, Q_CLOSE_HANDLE, handle_id);
 }

apps/buffering.h

@@ -36,6 +36,7 @@ enum data_type {
     TYPE_ATOMIC_AUDIO,
     TYPE_CUESHEET,
     TYPE_BITMAP,
+    TYPE_RAW_ATOMIC,
 };
 
 /* Error return values */
@@ -74,8 +75,6 @@ bool buffering_reset(char *buf, size_t buflen);
  * NOTE: Tail operations are only legal when the end of the file is buffered.
  ****************************************************************************/
 
-#define BUF_MAX_HANDLES         256
-
 int bufopen(const char *file, size_t offset, enum data_type type,
             void *user_data);
 int bufalloc(const void *src, size_t size, enum data_type type);

firmware/export/system.h

@@ -97,6 +97,11 @@ int get_cpu_boost_counter(void);
 #define MAX(a, b) (((a)>(b))?(a):(b))
 #endif
 
+#ifndef SGN
+#define SGN(a) \
+    ({ typeof (a) ___a = (a); (___a > 0) - (___a < 0); })
+#endif
+
 /* return number of elements in array a */
 #define ARRAYLEN(a) (sizeof(a)/sizeof((a)[0]))