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ring.h revision 1.8 
      1 /*	$NetBSD: ring.h,v 1.8 2000/06/22 06:47:48 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	from: @(#)ring.h	8.1 (Berkeley) 6/6/93
     36  */
     37 
     38 #include <sys/cdefs.h>
     39 #define P __P
     40 
     41 /*
     42  * This defines a structure for a ring buffer.
     43  *
     44  * The circular buffer has two parts:
     45  *(((
     46  *	full:	[consume, supply)
     47  *	empty:	[supply, consume)
     48  *]]]
     49  *
     50  */
     51 typedef struct {
     52     unsigned char	*consume,	/* where data comes out of */
     53 			*supply,	/* where data comes in to */
     54 			*bottom,	/* lowest address in buffer */
     55 			*top,		/* highest address+1 in buffer */
     56 			*mark;		/* marker (user defined) */
     57 #ifdef	ENCRYPTION
     58     unsigned char	*clearto;	/* Data to this point is clear text */
     59     unsigned char	*encryyptedto;	/* Data is encrypted to here */
     60 #endif	/* ENCRYPTION */
     61     int		size;		/* size in bytes of buffer */
     62     u_long	consumetime,	/* help us keep straight full, empty, etc. */
     63 		supplytime;
     64 } Ring;
     65 
     66 /* Ring buffer structures which are shared */
     67 
     68 extern Ring
     69     netoring,
     70     netiring,
     71     ttyoring,
     72     ttyiring;
     73 
     74 /* Here are some functions and macros to deal with the ring buffer */
     75 
     76 /* Initialization routine */
     77 extern int
     78 	ring_init P((Ring *ring, unsigned char *buffer, int count));
     79 
     80 /* Data movement routines */
     81 extern void
     82 	ring_supply_data P((Ring *ring, unsigned char *buffer, int count));
     83 #ifdef notdef
     84 extern void
     85 	ring_consume_data P((Ring *ring, unsigned char *buffer, int count));
     86 #endif
     87 
     88 /* Buffer state transition routines */
     89 extern void
     90 	ring_supplied P((Ring *ring, int count)),
     91 	ring_consumed P((Ring *ring, int count));
     92 
     93 /* Buffer state query routines */
     94 extern int
     95 	ring_empty_count P((Ring *ring)),
     96 	ring_empty_consecutive P((Ring *ring)),
     97 	ring_full_count P((Ring *ring)),
     98 	ring_full_consecutive P((Ring *ring)),
     99 	ring_at_mark P((Ring *ring));
    100 
    101 #ifdef	ENCRYPTION
    102 extern void
    103 	ring_encrypt P((Ring *ring, void (*func)(unsigned char *, int))),
    104 	ring_clearto P((Ring *ring));
    105 #endif	/* ENCRYPTION */
    106 
    107 extern void
    108 	ring_clear_mark P((Ring *ring)),
    109 	ring_mark P((Ring *ring));
    110