rockbox/apps/buffering.h
Michael Sevakis dfff938dff Get rid of useless playlist probing and fix up some data types.
Playback checked the files' presence before attempting to buffer
the track. Just get rid of that and save an extra open/close call.
It will find out if the path is bad when the metadata fails.

Fix some size_t/off_t conflation. No need to update plugin version
because no plugin actually uses bufopen().

Change-Id: I3db112449dc0b2eeb91c546f308880ac82494fc7
2017-12-17 16:33:50 -05:00

130 lines
4.6 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 "config.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,
TYPE_RAW_ATOMIC,
};
/* 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
#define ERR_WRONG_THREAD -7
/* Initialise the buffering subsystem */
void buffering_init(void) INIT_ATTR;
/* 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.
****************************************************************************/
int bufopen(const char *file, off_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
****************************************************************************/
bool buf_is_handle(int handle_id);
int buf_handle_data_type(int handle_id);
off_t buf_filesize(int handle_id);
off_t buf_handle_offset(int handle_id);
off_t buf_handle_remaining(int handle_id);
bool buf_pin_handle(int handle_id, bool pin);
bool buf_signal_handle(int handle_id, bool signal);
size_t buf_length(void);
size_t buf_used(void);
/* Settings */
void buf_set_base_handle(int handle_id);
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 data_rem;
size_t useful_data;
size_t watermark;
};
void buffering_get_debugdata(struct buffering_debug *dbgdata);
#endif