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/***************************************************************************
* __________ __ ___.
* 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 "appevents.h"
enum data_type {
TYPE_UNKNOWN = 0, /* invalid type indicator */
TYPE_ID3,
TYPE_CODEC,
TYPE_PACKET_AUDIO,
TYPE_ATOMIC_AUDIO,
TYPE_CUESHEET,
TYPE_BITMAP,
};
/* 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
#define ERR_UNSUPPORTED_TYPE -6
/* 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
* bufftell : Return the handle's file read 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,
void *user_data);
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);
off_t bufftell(int handle_id);
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_handle_data_type: return the handle's data type
* buf_is_handle: is the handle valid?
* buf_pin_handle: Disallow/allow handle movement. Handle may still be removed.
* buf_handle_offset: Get the offset of the first buffered byte from the file
* buf_set_base_handle: Tell the buffering thread which handle is currently read
* buf_length: Total size of ringbuffer
* buf_used: Total amount of buffer space used (including allocated space)
* buf_back_off_storage: tell buffering thread to take it easy
****************************************************************************/
enum data_type buf_handle_data_type(int handle_id);
ssize_t buf_handle_remaining(int handle_id);
bool buf_is_handle(int handle_id);
ssize_t buf_handle_offset(int handle_id);
void buf_set_base_handle(int handle_id);
size_t buf_length(void);
size_t buf_used(void);
bool buf_pin_handle(int handle_id, bool pin);
bool buf_signal_handle(int handle_id, bool signal);
#ifdef HAVE_IO_PRIORITY
void buf_back_off_storage(bool back_off);
#endif
/* Settings */
enum {
BUFFERING_SET_WATERMARK = 1,
BUFFERING_SET_CHUNKSIZE,
};
void buf_set_watermark(size_t bytes);
size_t buf_get_watermark(void);
/* Debugging */
struct buffering_debug {
int num_handles;
size_t buffered_data;
size_t wasted_space;
size_t data_rem;
size_t useful_data;
size_t watermark;
};
void buffering_get_debugdata(struct buffering_debug *dbgdata);
#endif
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