1 /* $OpenBSD: ring.h,v 1.6 2003/06/03 02:56:18 millert Exp $ */ 2 /* $NetBSD: ring.h,v 1.5 1996/02/28 21:04:09 thorpej Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)ring.h 8.1 (Berkeley) 6/6/93 33 */ 34 35 /* 36 * This defines a structure for a ring buffer. 37 * 38 * The circular buffer has two parts: 39 *((( 40 * full: [consume, supply) 41 * empty: [supply, consume) 42 *]]] 43 * 44 */ 45 typedef struct { 46 unsigned char *consume, /* where data comes out of */ 47 *supply, /* where data comes in to */ 48 *bottom, /* lowest address in buffer */ 49 *top, /* highest address+1 in buffer */ 50 *mark; /* marker (user defined) */ 51 #if defined(ENCRYPTION) 52 unsigned char *clearto; /* Data to this point is clear text */ 53 unsigned char *encryyptedto; /* Data is encrypted to here */ 54 #endif 55 int size; /* size in bytes of buffer */ 56 u_long consumetime, /* help us keep straight full, empty, etc. */ 57 supplytime; 58 } Ring; 59 60 /* Here are some functions and macros to deal with the ring buffer */ 61 62 /* Initialization routine */ 63 extern int 64 ring_init(Ring *ring, unsigned char *buffer, int count); 65 66 /* Data movement routines */ 67 extern void 68 ring_supply_data(Ring *ring, unsigned char *buffer, int count); 69 #ifdef notdef 70 extern void 71 ring_consume_data(Ring *ring, unsigned char *buffer, int count); 72 #endif 73 74 /* Buffer state transition routines */ 75 extern void 76 ring_supplied(Ring *ring, int count), 77 ring_consumed(Ring *ring, int count); 78 79 /* Buffer state query routines */ 80 extern int 81 ring_empty_count(Ring *ring), 82 ring_empty_consecutive(Ring *ring), 83 ring_full_count(Ring *ring), 84 ring_full_consecutive(Ring *ring); 85 86 #if defined(ENCRYPTION) 87 extern void 88 ring_encrypt (Ring *ring, void (*func)()), 89 ring_clearto (Ring *ring); 90 #endif 91 92 93 extern void 94 ring_clear_mark(Ring *), 95 ring_mark(Ring *); 96 97 98 extern int 99 ring_at_mark(Ring *); 100