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 * $FreeBSD$ 35 */ 36 37 #if defined(P) 38 # undef P 39 #endif 40 41 #if defined(__STDC__) || defined(LINT_ARGS) 42 # define P(x) x 43 #else 44 # define P(x) () 45 #endif 46 47 /* 48 * This defines a structure for a ring buffer. 49 * 50 * The circular buffer has two parts: 51 *((( 52 * full: [consume, supply) 53 * empty: [supply, consume) 54 *]]] 55 * 56 */ 57 typedef struct { 58 unsigned char *consume, /* where data comes out of */ 59 *supply, /* where data comes in to */ 60 *bottom, /* lowest address in buffer */ 61 *top, /* highest address+1 in buffer */ 62 *mark; /* marker (user defined) */ 63 #ifdef ENCRYPTION 64 unsigned char *clearto; /* Data to this point is clear text */ 65 unsigned char *encryyptedto; /* Data is encrypted to here */ 66 #endif /* ENCRYPTION */ 67 int size; /* size in bytes of buffer */ 68 u_long consumetime, /* help us keep straight full, empty, etc. */ 69 supplytime; 70 } Ring; 71 72 /* Here are some functions and macros to deal with the ring buffer */ 73 74 /* Initialization routine */ 75 extern int 76 ring_init(Ring *ring, unsigned char *buffer, int count); 77 78 /* Data movement routines */ 79 extern void 80 ring_supply_data(Ring *ring, unsigned char *buffer, int count); 81 #ifdef notdef 82 extern void 83 ring_consume_data(Ring *ring, unsigned char *buffer, int count); 84 #endif 85 86 /* Buffer state transition routines */ 87 extern void 88 ring_supplied(Ring *ring, int count), 89 ring_consumed(Ring *ring, int count); 90 91 /* Buffer state query routines */ 92 extern int 93 ring_at_mark(Ring *), 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 99 #ifdef ENCRYPTION 100 extern void 101 ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)), 102 ring_clearto(Ring *ring); 103 #endif /* ENCRYPTION */ 104 105 extern void 106 ring_clear_mark(Ring *), 107 ring_mark(Ring *); 108