usr.bin/telnet/ring.h

   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 *);