1 /* $NetBSD: ring.h,v 1.10 2003/08/07 11:16:10 agc 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * from: @(#)ring.h 8.1 (Berkeley) 6/6/93 32 */ 33 34 #include <sys/cdefs.h> 35 36 /* 37 * This defines a structure for a ring buffer. 38 * 39 * The circular buffer has two parts: 40 *((( 41 * full: [consume, supply) 42 * empty: [supply, consume) 43 *]]] 44 * 45 */ 46 typedef struct { 47 unsigned char *consume, /* where data comes out of */ 48 *supply, /* where data comes in to */ 49 *bottom, /* lowest address in buffer */ 50 *top, /* highest address+1 in buffer */ 51 *mark; /* marker (user defined) */ 52 #ifdef ENCRYPTION 53 unsigned char *clearto; /* Data to this point is clear text */ 54 unsigned char *encryyptedto; /* Data is encrypted to here */ 55 #endif /* ENCRYPTION */ 56 int size; /* size in bytes of buffer */ 57 u_long consumetime, /* help us keep straight full, empty, etc. */ 58 supplytime; 59 } Ring; 60 61 /* Ring buffer structures which are shared */ 62 63 extern Ring 64 netoring, 65 netiring, 66 ttyoring, 67 ttyiring; 68 69 /* Here are some functions and macros to deal with the ring buffer */ 70 71 /* Initialization routine */ 72 extern int 73 ring_init(Ring *ring, unsigned char *buffer, int count); 74 75 /* Data movement routines */ 76 extern void 77 ring_supply_data(Ring *ring, unsigned char *buffer, int count); 78 #ifdef notdef 79 extern void 80 ring_consume_data(Ring *ring, unsigned char *buffer, int count); 81 #endif 82 83 /* Buffer state transition routines */ 84 extern void 85 ring_supplied(Ring *ring, int count), 86 ring_consumed(Ring *ring, int count); 87 88 /* Buffer state query routines */ 89 extern int 90 ring_empty_count(Ring *ring), 91 ring_empty_consecutive(Ring *ring), 92 ring_full_count(Ring *ring), 93 ring_full_consecutive(Ring *ring), 94 ring_at_mark(Ring *ring); 95 96 #ifdef ENCRYPTION 97 extern void 98 ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)), 99 ring_clearto(Ring *ring); 100 #endif /* ENCRYPTION */ 101 102 extern void 103 ring_clear_mark(Ring *ring), 104 ring_mark(Ring *ring); 105