141 lines
5.4 KiB
C
141 lines
5.4 KiB
C
/*
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reader: reading input data
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copyright ?-2007 by the mpg123 project - free software under the terms of the LGPL 2.1
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see COPYING and AUTHORS files in distribution or http://mpg123.org
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initially written by Thomas Orgis (after code from Michael Hipp)
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*/
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#ifndef MPG123_READER_H
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#define MPG123_READER_H
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#include "config.h"
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#include "mpg123.h"
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#ifndef NO_FEEDER
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struct buffy
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{
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unsigned char *data;
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ssize_t size;
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ssize_t realsize;
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struct buffy *next;
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};
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struct bufferchain
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{
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struct buffy* first; /* The beginning of the chain. */
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struct buffy* last; /* The end... of the chain. */
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ssize_t size; /* Aggregated size of all buffies. */
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/* These positions are relative to buffer chain beginning. */
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ssize_t pos; /* Position in whole chain. */
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ssize_t firstpos; /* The point of return on non-forget() */
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/* The "real" filepos is fileoff + pos. */
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off_t fileoff; /* Beginning of chain is at this file offset. */
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size_t bufblock; /* Default (minimal) size of buffers. */
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size_t pool_size; /* Keep that many buffers in storage. */
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size_t pool_fill; /* That many buffers are there. */
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/* A pool of buffers to re-use, if activated. It's a linked list that is worked on from the front. */
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struct buffy *pool;
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};
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/* Call this before any buffer chain use (even bc_init()). */
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void bc_prepare(struct bufferchain *, size_t pool_size, size_t bufblock);
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/* Free persistent data in the buffer chain, after bc_reset(). */
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void bc_cleanup(struct bufferchain *);
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/* Change pool size. This does not actually allocate/free anything on itself, just instructs later operations to free less / allocate more buffers. */
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void bc_poolsize(struct bufferchain *, size_t pool_size, size_t bufblock);
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/* Return available byte count in the buffer. */
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size_t bc_fill(struct bufferchain *bc);
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#endif
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struct reader_data
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{
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off_t filelen; /* total file length or total buffer size */
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off_t filepos; /* position in file or position in buffer chain */
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int filept;
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/* Custom opaque I/O handle from the client. */
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void *iohandle;
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int flags;
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long timeout_sec;
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ssize_t (*fdread) (mpg123_handle *, void *, size_t);
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/* User can replace the read and lseek functions. The r_* are the stored replacement functions or NULL. */
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ssize_t (*r_read) (int fd, void *buf, size_t count);
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off_t (*r_lseek)(int fd, off_t offset, int whence);
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/* These are custom I/O routines for opaque user handles.
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They get picked if there's some iohandle set. */
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ssize_t (*r_read_handle) (void *handle, void *buf, size_t count);
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off_t (*r_lseek_handle)(void *handle, off_t offset, int whence);
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/* An optional cleaner for the handle on closing the stream. */
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void (*cleanup_handle)(void *handle);
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/* These two pointers are the actual workers (default map to POSIX read/lseek). */
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ssize_t (*read) (int fd, void *buf, size_t count);
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off_t (*lseek)(int fd, off_t offset, int whence);
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/* Buffered readers want that abstracted, set internally. */
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ssize_t (*fullread)(mpg123_handle *, unsigned char *, ssize_t);
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#ifndef NO_FEEDER
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struct bufferchain buffer; /* Not dynamically allocated, these few struct bytes aren't worth the trouble. */
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#endif
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};
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/* start to use off_t to properly do LFS in future ... used to be long */
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#ifdef __MORPHOS__
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#undef tell /* unistd.h defines it as lseek(x, 0L, 1) */
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#endif
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struct reader
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{
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int (*init) (mpg123_handle *);
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void (*close) (mpg123_handle *);
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ssize_t (*fullread) (mpg123_handle *, unsigned char *, ssize_t);
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int (*head_read) (mpg123_handle *, unsigned long *newhead); /* succ: TRUE, else <= 0 (FALSE or READER_MORE) */
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int (*head_shift) (mpg123_handle *, unsigned long *head); /* succ: TRUE, else <= 0 (FALSE or READER_MORE) */
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off_t (*skip_bytes) (mpg123_handle *, off_t len); /* succ: >=0, else error or READER_MORE */
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int (*read_frame_body)(mpg123_handle *, unsigned char *, int size);
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int (*back_bytes) (mpg123_handle *, off_t bytes);
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int (*seek_frame) (mpg123_handle *, off_t num);
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off_t (*tell) (mpg123_handle *);
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void (*rewind) (mpg123_handle *);
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void (*forget) (mpg123_handle *);
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};
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/* Open a file by path or use an opened file descriptor. */
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int open_stream(mpg123_handle *, const char *path, int fd);
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/* Open an external handle. */
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int open_stream_handle(mpg123_handle *, void *iohandle);
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/* feed based operation has some specials */
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int open_feed(mpg123_handle *);
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/* externally called function, returns 0 on success, -1 on error */
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int feed_more(mpg123_handle *fr, const unsigned char *in, long count);
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void feed_forget(mpg123_handle *fr); /* forget the data that has been read (free some buffers) */
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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. */
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void open_bad(mpg123_handle *);
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#define READER_FD_OPENED 0x1
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#define READER_ID3TAG 0x2
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#define READER_SEEKABLE 0x4
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#define READER_BUFFERED 0x8
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#define READER_NONBLOCK 0x20
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#define READER_HANDLEIO 0x40
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#define READER_STREAM 0
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#define READER_ICY_STREAM 1
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#define READER_FEED 2
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/* These two add a little buffering to enable small seeks for peek ahead. */
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#define READER_BUF_STREAM 3
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#define READER_BUF_ICY_STREAM 4
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#ifdef READ_SYSTEM
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#define READER_SYSTEM 5
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#define READERS 6
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#else
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#define READERS 5
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#endif
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#define READER_ERROR MPG123_ERR
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#define READER_MORE MPG123_NEED_MORE
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#endif
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