1 /*
2  * Copyright 2001-2002 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1988, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)ring.h	8.1 (Berkeley) 6/6/93
39  */
40 
41 #ifndef _RING_H
42 #define	_RING_H
43 
44 #ifdef	__cplusplus
45 extern "C" {
46 #endif
47 
48 /*
49  * This defines a structure for a ring buffer.
50  *
51  * The circular buffer has two parts:
52  * (((
53  *	full:	[consume, supply)
54  *	empty:	[supply, consume)
55  * ]]]
56  *
57  */
58 typedef struct {
59     unsigned char *consume;	/* where data comes out of */
60     unsigned char *supply;	/* where data comes in to */
61     unsigned char *bottom;	/* lowest address in buffer */
62     unsigned char *top;		/* highest address+1 in buffer */
63     unsigned char *mark;	/* marker (user defined) */
64     unsigned char *clearto;	/* Data to this point is clear text */
65     unsigned char *encryyptedto; /* Data is encrypted to here */
66     int		size;		/* size in bytes of buffer */
67     ulong_t	consumetime;	/* help us keep straight full, empty, etc. */
68     ulong_t	supplytime;
69 } Ring;
70 
71 /* Here are some functions and macros to deal with the ring buffer */
72 
73 /* Initialization routine */
74 extern int ring_init(Ring *ring, unsigned char *buffer, int count);
75 
76 /* Data movement routines */
77 extern void ring_supply_data(Ring *ring, unsigned char *buffer, int count);
78 #ifdef notdef
79 extern void ring_consume_data(Ring *ring, unsigned char *buffer, int count);
80 #endif
81 
82 /* Buffer state transition routines */
83 extern void ring_supplied(Ring *ring, int count);
84 extern void ring_consumed(Ring *ring, int count);
85 
86 /* Buffer state query routines */
87 extern int ring_at_mark(Ring *ring);
88 extern int ring_empty_count(Ring *ring);
89 extern int ring_empty_consecutive(Ring *ring);
90 extern int ring_full_count(Ring *ring);
91 extern int ring_full_consecutive(Ring *ring);
92 
93 extern void ring_encrypt(Ring *ring, void (*func)());
94 extern void ring_clearto(Ring *ring);
95 
96 extern void ring_clear_mark();
97 extern void ring_mark();
98 
99 
100 #ifdef	__cplusplus
101 }
102 #endif
103 
104 #endif	/* _RING_H */
105