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/* $OpenBSD: abuf.h,v 1.24 2011/11/15 20:41:54 ratchov Exp $ */
/*
* Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef ABUF_H
#define ABUF_H
#include <sys/queue.h>
struct aproc;
struct aparams;
struct abuf {
LIST_ENTRY(abuf) ient; /* reader's list of inputs entry */
LIST_ENTRY(abuf) oent; /* writer's list of outputs entry */
/*
* fifo parameters
*/
unsigned bpf; /* bytes per frame */
unsigned cmin, cmax; /* channel range of this buf */
unsigned start; /* offset where data starts */
unsigned used; /* valid data */
unsigned len; /* size of the ring */
struct aproc *rproc; /* reader */
struct aproc *wproc; /* writer */
struct abuf *duplex; /* link to buffer of the other direction */
unsigned inuse; /* in abuf_{flush,fill,run}() */
unsigned tickets; /* max data to (if throttling) */
/*
* Misc reader aproc-specific per-buffer parameters.
*/
union {
struct {
int weight; /* dynamic range */
int maxweight; /* max dynamic range allowed */
unsigned vol; /* volume within the dynamic range */
unsigned done; /* frames ready */
unsigned xrun; /* underrun policy */
int drop; /* frames to drop on next read */
} mix;
struct {
unsigned st; /* MIDI running status */
unsigned used; /* bytes used from ``msg'' */
unsigned idx; /* actual MIDI message size */
unsigned len; /* MIDI message length */
#define MIDI_MSGMAX 16 /* max size of MIDI messaage */
unsigned char msg[MIDI_MSGMAX];
} midi;
} r;
/*
* Misc reader aproc-specific per-buffer parameters.
*/
union {
struct {
unsigned todo; /* frames to process */
} mix;
struct {
unsigned done; /* frames copied */
unsigned xrun; /* overrun policy, one of XRUN_XXX */
int silence; /* silence to add on next write */
} sub;
struct {
struct abuf *owner; /* current input stream */
} midi;
} w;
};
/*
* the buffer contains at least one frame. This macro should
* be used to check if the buffer can be flushed
*/
#define ABUF_ROK(b) ((b)->used > 0)
/*
* there's room for at least one frame
*/
#define ABUF_WOK(b) ((b)->len - (b)->used > 0)
/*
* the buffer is empty and has no writer anymore
*/
#define ABUF_EOF(b) (!ABUF_ROK(b) && (b)->wproc == NULL)
/*
* the buffer has no reader anymore, note that it's not
* enough the buffer to be disconnected, because it can
* be not yet connected buffer (eg. socket play buffer)
*/
#define ABUF_HUP(b) (!ABUF_WOK(b) && (b)->rproc == NULL)
struct abuf *abuf_new(unsigned, struct aparams *);
void abuf_del(struct abuf *);
void abuf_dbg(struct abuf *);
void abuf_clear(struct abuf *);
unsigned char *abuf_rgetblk(struct abuf *, unsigned *, unsigned);
unsigned char *abuf_wgetblk(struct abuf *, unsigned *, unsigned);
void abuf_rdiscard(struct abuf *, unsigned);
void abuf_wcommit(struct abuf *, unsigned);
int abuf_fill(struct abuf *);
int abuf_flush(struct abuf *);
void abuf_eof(struct abuf *);
void abuf_hup(struct abuf *);
void abuf_run(struct abuf *);
void abuf_ipos(struct abuf *, int);
void abuf_opos(struct abuf *, int);
#endif /* !defined(ABUF_H) */
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