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 #if defined(P) 37 # undef P 38 #endif 39 40 #if defined(__STDC__) || defined(LINT_ARGS) 41 # define P(x) x 42 #else 43 # define P(x) () 44 #endif 45 46 /* 47 * This defines a structure for a ring buffer. 48 * 49 * The circular buffer has two parts: 50 *((( 51 * full: [consume, supply) 52 * empty: [supply, consume) 53 *]]] 54 * 55 */ 56 typedef struct { 57 unsigned char *consume, /* where data comes out of */ 58 *supply, /* where data comes in to */ 59 *bottom, /* lowest address in buffer */ 60 *top, /* highest address+1 in buffer */ 61 *mark; /* marker (user defined) */ 62 #ifdef ENCRYPTION 63 unsigned char *clearto; /* Data to this point is clear text */ 64 unsigned char *encryyptedto; /* Data is encrypted to here */ 65 #endif /* ENCRYPTION */ 66 int size; /* size in bytes of buffer */ 67 u_long consumetime, /* help us keep straight full, empty, etc. */ 68 supplytime; 69 } Ring; 70 71 /* Here are some functions and macros to deal with the ring buffer */ 72 73 /* Initialization routine */ 74 extern int 75 ring_init P((Ring *ring, unsigned char *buffer, int count)); 76 77 /* Data movement routines */ 78 extern void 79 ring_supply_data P((Ring *ring, unsigned char *buffer, int count)); 80 #ifdef notdef 81 extern void 82 ring_consume_data P((Ring *ring, unsigned char *buffer, int count)); 83 #endif 84 85 /* Buffer state transition routines */ 86 extern void 87 ring_supplied P((Ring *ring, int count)), 88 ring_consumed P((Ring *ring, int count)); 89 90 /* Buffer state query routines */ 91 extern int 92 ring_empty_count P((Ring *ring)), 93 ring_empty_consecutive P((Ring *ring)), 94 ring_full_count P((Ring *ring)), 95 ring_full_consecutive P((Ring *ring)); 96 97 #ifdef ENCRYPTION 98 extern void 99 ring_encrypt P((Ring *ring, void (*func)())), 100 ring_clearto P((Ring *ring)); 101 #endif /* ENCRYPTION */ 102 103 extern void 104 ring_clear_mark(), 105 ring_mark(); 106