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