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