1 files changed, 120 insertions, 0 deletions

diff --git a/apps/buffering.h b/apps/buffering.h
new file mode 100644
index 0000000000..a5ad1e283b
--- /dev/null
+++ b/apps/buffering.h
@@ -0,0 +1,120 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2007 Nicolas Pennequin
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#ifndef _BUFFERING_H_
+#define _BUFFERING_H_
+
+#include <sys/types.h>
+#include <stdbool.h>
+
+
+enum data_type {
+    TYPE_CODEC,
+    TYPE_AUDIO,
+    TYPE_STREAM,
+    TYPE_ID3,
+    TYPE_CUESHEET,
+    TYPE_IMAGE,
+    TYPE_BUFFER,
+    TYPE_UNKNOWN,
+};
+
+
+/* Initialise the buffering subsystem */
+bool buffering_init(char *buf, size_t buflen);
+
+
+/***************************************************************************
+ * MAIN BUFFERING API CALLS
+ * ========================
+ *
+ * bufopen   : Reserve space in the buffer for a given file
+ * bufalloc  : Open a new handle from data that needs to be copied from memory
+ * bufclose  : Close an open handle
+ * bufseek   : Set handle reading index, relatively to the start of the file
+ * bufadvance: Move handle reading index, relatively to current position
+ * bufread   : Copy data from a handle to a buffer
+ * bufgetdata: Obtain a pointer for linear access to a "size" amount of data
+ ****************************************************************************/
+
+int bufopen(const char *file, size_t offset, enum data_type type);
+int bufalloc(const void *src, size_t size, enum data_type type);
+bool bufclose(int handle_id);
+int bufseek(int handle_id, size_t newpos);
+int bufadvance(int handle_id, off_t offset);
+ssize_t bufread(int handle_id, size_t size, void *dest);
+ssize_t bufgetdata(int handle_id, size_t size, void **data);
+
+
+/***************************************************************************
+ * SECONDARY FUNCTIONS
+ * ===================
+ *
+ * buf_get_offset: Get a handle offset from a pointer
+ * buf_handle_offset: Get the offset of the first buffered byte from the file
+ * buf_request_buffer_handle: Request buffering of a handle
+ * buf_set_base_handle: Tell the buffering thread which handle is currently read
+ * buf_used: Total amount of buffer space used (including allocated space)
+ ****************************************************************************/
+
+ssize_t buf_get_offset(int handle_id, void *ptr);
+ssize_t buf_handle_offset(int handle_id);
+void buf_request_buffer_handle(int handle_id);
+void buf_set_base_handle(int handle_id);
+size_t buf_used(void);
+
+
+/***************************************************************************
+ * CALLBACK UTILITIES
+ * ==================
+ *
+ * register_buffer_low_callback, unregister_buffer_low_callback:
+ *
+ * Register/Unregister callback functions that will get executed when the buffer
+ * goes below the low watermark. They are executed once, then forgotten.
+ *
+ * NOTE: The callbacks are called from the buffering thread, so don't make them
+ * do too much. Ideally they should just post an event to a queue and return.
+ ****************************************************************************/
+
+#define MAX_BUF_CALLBACKS 4
+typedef void (*buffer_low_callback)(void);
+bool register_buffer_low_callback(buffer_low_callback func);
+void unregister_buffer_low_callback(buffer_low_callback func);
+
+/* Settings */
+enum {
+    BUFFERING_SET_WATERMARK = 1,
+    BUFFERING_SET_CHUNKSIZE,
+    BUFFERING_SET_PRESEEK,
+};
+void buf_set_conf(int setting, size_t value);
+
+
+/* Debugging */
+struct buffering_debug {
+    int num_handles;
+    size_t buffered_data;
+    size_t wasted_space;
+    size_t data_rem;
+    size_t useful_data;
+};
+void buffering_get_debugdata(struct buffering_debug *dbgdata);
+
+#endif