rockbox/apps/buffering.h
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

133 lines
4.3 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 Nicolas Pennequin
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* 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>
#include "events.h"
enum data_type {
TYPE_CODEC,
TYPE_PACKET_AUDIO,
TYPE_ATOMIC_AUDIO,
TYPE_ID3,
TYPE_CUESHEET,
TYPE_BITMAP,
TYPE_BUFFER,
TYPE_UNKNOWN,
};
enum callback_event {
EVENT_BUFFER_LOW = (EVENT_CLASS_BUFFERING|1),
EVENT_HANDLE_REBUFFER,
EVENT_HANDLE_CLOSED,
EVENT_HANDLE_MOVED,
EVENT_HANDLE_FINISHED,
};
/* Error return values */
#define ERR_HANDLE_NOT_FOUND -1
#define ERR_BUFFER_FULL -2
#define ERR_INVALID_VALUE -3
#define ERR_FILE_ERROR -4
#define ERR_HANDLE_NOT_DONE -5
/* Initialise the buffering subsystem */
void buffering_init(void);
/* Reset the buffering system */
bool buffering_reset(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
* bufgettail: Out-of-band get the last size bytes of a handle.
* bufcuttail: Out-of-band remove the trailing 'size' bytes of a handle.
*
* NOTE: bufread and bufgetdata will block the caller until the requested
* amount of data is ready (unless EOF is reached).
* 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);
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);
ssize_t bufgettail(int handle_id, size_t size, void **data);
ssize_t bufcuttail(int handle_id, size_t size);
/***************************************************************************
* 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);
/* Settings */
enum {
BUFFERING_SET_WATERMARK = 1,
BUFFERING_SET_CHUNKSIZE,
};
void buf_set_watermark(size_t bytes);
/* 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