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