1 /* $NetBSD: ring.h,v 1.9 2002/06/14 00:30:57 wiz 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 40 /* 41 * This defines a structure for a ring buffer. 42 * 43 * The circular buffer has two parts: 44 *((( 45 * full: [consume, supply) 46 * empty: [supply, consume) 47 *]]] 48 * 49 */ 50 typedef struct { 51 unsigned char *consume, /* where data comes out of */ 52 *supply, /* where data comes in to */ 53 *bottom, /* lowest address in buffer */ 54 *top, /* highest address+1 in buffer */ 55 *mark; /* marker (user defined) */ 56 #ifdef ENCRYPTION 57 unsigned char *clearto; /* Data to this point is clear text */ 58 unsigned char *encryyptedto; /* Data is encrypted to here */ 59 #endif /* ENCRYPTION */ 60 int size; /* size in bytes of buffer */ 61 u_long consumetime, /* help us keep straight full, empty, etc. */ 62 supplytime; 63 } Ring; 64 65 /* Ring buffer structures which are shared */ 66 67 extern Ring 68 netoring, 69 netiring, 70 ttyoring, 71 ttyiring; 72 73 /* Here are some functions and macros to deal with the ring buffer */ 74 75 /* Initialization routine */ 76 extern int 77 ring_init(Ring *ring, unsigned char *buffer, int count); 78 79 /* Data movement routines */ 80 extern void 81 ring_supply_data(Ring *ring, unsigned char *buffer, int count); 82 #ifdef notdef 83 extern void 84 ring_consume_data(Ring *ring, unsigned char *buffer, int count); 85 #endif 86 87 /* Buffer state transition routines */ 88 extern void 89 ring_supplied(Ring *ring, int count), 90 ring_consumed(Ring *ring, int count); 91 92 /* Buffer state query routines */ 93 extern int 94 ring_empty_count(Ring *ring), 95 ring_empty_consecutive(Ring *ring), 96 ring_full_count(Ring *ring), 97 ring_full_consecutive(Ring *ring), 98 ring_at_mark(Ring *ring); 99 100 #ifdef ENCRYPTION 101 extern void 102 ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)), 103 ring_clearto(Ring *ring); 104 #endif /* ENCRYPTION */ 105 106 extern void 107 ring_clear_mark(Ring *ring), 108 ring_mark(Ring *ring); 109