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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ring.h 8.1 (Berkeley) 6/6/93 30 * $FreeBSD$ 31 */ 32 33 #if defined(P) 34 # undef P 35 #endif 36 37 #if defined(__STDC__) || defined(LINT_ARGS) 38 # define P(x) x 39 #else 40 # define P(x) () 41 #endif 42 43 /* 44 * This defines a structure for a ring buffer. 45 * 46 * The circular buffer has two parts: 47 *((( 48 * full: [consume, supply) 49 * empty: [supply, consume) 50 *]]] 51 * 52 */ 53 typedef struct { 54 unsigned char *consume, /* where data comes out of */ 55 *supply, /* where data comes in to */ 56 *bottom, /* lowest address in buffer */ 57 *top, /* highest address+1 in buffer */ 58 *mark; /* marker (user defined) */ 59 #ifdef ENCRYPTION 60 unsigned char *clearto; /* Data to this point is clear text */ 61 unsigned char *encryyptedto; /* Data is encrypted to here */ 62 #endif /* ENCRYPTION */ 63 int size; /* size in bytes of buffer */ 64 u_long consumetime, /* help us keep straight full, empty, etc. */ 65 supplytime; 66 } Ring; 67 68 /* Here are some functions and macros to deal with the ring buffer */ 69 70 /* Initialization routine */ 71 extern int 72 ring_init(Ring *ring, unsigned char *buffer, int count); 73 74 /* Data movement routines */ 75 extern void 76 ring_supply_data(Ring *ring, unsigned char *buffer, int count); 77 #ifdef notdef 78 extern void 79 ring_consume_data(Ring *ring, unsigned char *buffer, int count); 80 #endif 81 82 /* Buffer state transition routines */ 83 extern void 84 ring_supplied(Ring *ring, int count), 85 ring_consumed(Ring *ring, int count); 86 87 /* Buffer state query routines */ 88 extern int 89 ring_at_mark(Ring *), 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 95 #ifdef ENCRYPTION 96 extern void 97 ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)), 98 ring_clearto(Ring *ring); 99 #endif /* ENCRYPTION */ 100 101 extern void 102 ring_clear_mark(Ring *), 103 ring_mark(Ring *); 104