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: src/usr.bin/telnet/ring.h,v 1.2.14.1 2002/04/13 11:07:13 markm Exp $ 35 * $DragonFly: src/usr.bin/telnet/ring.h,v 1.2 2003/06/17 04:29:32 dillon Exp $ 36 */ 37 38 #if defined(P) 39 # undef P 40 #endif 41 42 #if defined(__STDC__) || defined(LINT_ARGS) 43 # define P(x) x 44 #else 45 # define P(x) () 46 #endif 47 48 /* 49 * This defines a structure for a ring buffer. 50 * 51 * The circular buffer has two parts: 52 *((( 53 * full: [consume, supply) 54 * empty: [supply, consume) 55 *]]] 56 * 57 */ 58 typedef struct { 59 unsigned char *consume, /* where data comes out of */ 60 *supply, /* where data comes in to */ 61 *bottom, /* lowest address in buffer */ 62 *top, /* highest address+1 in buffer */ 63 *mark; /* marker (user defined) */ 64 int size; /* size in bytes of buffer */ 65 u_long consumetime, /* help us keep straight full, empty, etc. */ 66 supplytime; 67 } Ring; 68 69 /* Here are some functions and macros to deal with the ring buffer */ 70 71 /* Initialization routine */ 72 extern int 73 ring_init(Ring *ring, unsigned char *buffer, int count); 74 75 /* Data movement routines */ 76 extern void 77 ring_supply_data(Ring *ring, unsigned char *buffer, int count); 78 #ifdef notdef 79 extern void 80 ring_consume_data(Ring *ring, unsigned char *buffer, int count); 81 #endif 82 83 /* Buffer state transition routines */ 84 extern void 85 ring_supplied(Ring *ring, int count), 86 ring_consumed(Ring *ring, int count); 87 88 /* Buffer state query routines */ 89 extern int 90 ring_at_mark(Ring *), 91 ring_empty_count(Ring *ring), 92 ring_empty_consecutive(Ring *ring), 93 ring_full_count(Ring *ring), 94 ring_full_consecutive(Ring *ring); 95 96 97 extern void 98 ring_clear_mark(Ring *), 99 ring_mark(Ring *); 100