/*
reader: reading input data
copyright ?-2007 by the mpg123 project - free software under the terms of the LGPL 2.1
see COPYING and AUTHORS files in distribution or http://mpg123.org
initially written by Thomas Orgis (after code from Michael Hipp)
*/
#ifndef MPG123_READER_H
#define MPG123_READER_H
#include "config.h"
#include "mpg123.h"
struct buffy
{
unsigned char *data;
ssize_t size;
struct buffy *next;
};
struct bufferchain
{
struct buffy* first; /* The beginning of the chain. */
struct buffy* last; /* The end... of the chain. */
ssize_t size; /* Aggregated size of all buffies. */
/* These positions are relative to buffer chain beginning. */
ssize_t pos; /* Position in whole chain. */
ssize_t firstpos; /* The point of return on non-forget() */
/* The "real" filepos is fileoff + pos. */
off_t fileoff; /* Beginning of chain is at this file offset. */
};
struct reader_data
{
off_t filelen; /* total file length or total buffer size */
off_t filepos; /* position in file or position in buffer chain */
int filept;
int flags;
#ifndef WIN32
long timeout_sec;
#endif
ssize_t (*fdread) (mpg123_handle *, void *, size_t);
/* User can replace the read and lseek functions. The r_* are the stored replacement functions or NULL,
The second two pointers are the actual workers (default map to POSIX read/lseek). */
ssize_t (*r_read) (int fd, void *buf, size_t count);
off_t (*r_lseek)(int fd, off_t offset, int whence);
ssize_t (*read) (int fd, void *buf, size_t count);
off_t (*lseek)(int fd, off_t offset, int whence);
/* Buffered readers want that abstracted, set internally. */
ssize_t (*fullread)(mpg123_handle *, unsigned char *, ssize_t);
struct bufferchain buffer; /* Not dynamically allocated, these few struct bytes aren't worth the trouble. */
};
/* start to use off_t to properly do LFS in future ... used to be long */
struct reader
{
int (*init) (mpg123_handle *);
void (*close) (mpg123_handle *);
ssize_t (*fullread) (mpg123_handle *, unsigned char *, ssize_t);
int (*head_read) (mpg123_handle *, unsigned long *newhead); /* succ: TRUE, else <= 0 (FALSE or READER_MORE) */
int (*head_shift) (mpg123_handle *, unsigned long *head); /* succ: TRUE, else <= 0 (FALSE or READER_MORE) */
off_t (*skip_bytes) (mpg123_handle *, off_t len); /* succ: >=0, else error or READER_MORE */
int (*read_frame_body)(mpg123_handle *, unsigned char *, int size);
int (*back_bytes) (mpg123_handle *, off_t bytes);
int (*seek_frame) (mpg123_handle *, off_t num);
off_t (*tell) (mpg123_handle *);
void (*rewind) (mpg123_handle *);
void (*forget) (mpg123_handle *);
};
/* Open a file by path or use an opened file descriptor. */
int open_stream(mpg123_handle *, const char *path, int fd);
/* feed based operation has some specials */
int open_feed(mpg123_handle *);
/* externally called function, returns 0 on success, -1 on error */
int feed_more(mpg123_handle *fr, const unsigned char *in, long count);
void feed_forget(mpg123_handle *fr); /* forget the data that has been read (free some buffers) */
off_t feed_set_pos(mpg123_handle *fr, off_t pos); /* Set position (inside available data if possible), return wanted byte offset of next feed. */
void open_bad(mpg123_handle *);
#define READER_FD_OPENED 0x1
#define READER_ID3TAG 0x2
#define READER_SEEKABLE 0x4
#define READER_BUFFERED 0x8
#define READER_NONBLOCK 0x20
#define READER_STREAM 0
#define READER_ICY_STREAM 1
#define READER_FEED 2
/* These two add a little buffering to enable small seeks for peek ahead. */
#define READER_BUF_STREAM 3
#define READER_BUF_ICY_STREAM 4
#ifdef READ_SYSTEM
#define READER_SYSTEM 5
#define READERS 6
#else
#define READERS 5
#endif
#define READER_ERROR MPG123_ERR
#define READER_MORE MPG123_NEED_MORE
#endif