telnet.tproj/ring.h

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1988, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  *
  56  *      @(#)ring.h      8.1 (Berkeley) 6/6/93
  57  */
  58
  59 #if defined(P)
  60 # undef P
  61 #endif
  62
  63 #if defined(__STDC__) || defined(LINT_ARGS)
  64 # define        P(x)    x
  65 #else
  66 # define        P(x)    ()
  67 #endif
  68
  69 /*
  70  * This defines a structure for a ring buffer.
  71  *
  72  * The circular buffer has two parts:
  73  *(((
  74  *      full:   [consume, supply)
  75  *      empty:  [supply, consume)
  76  *]]]
  77  *
  78  */
  79 typedef struct {
  80     unsigned char       *consume,       /* where data comes out of */
  81                         *supply,        /* where data comes in to */
  82                         *bottom,        /* lowest address in buffer */
  83                         *top,           /* highest address+1 in buffer */
  84                         *mark;          /* marker (user defined) */
  85 #ifdef  ENCRYPTION
  86     unsigned char       *clearto;       /* Data to this point is clear text */
  87     unsigned char       *encryyptedto;  /* Data is encrypted to here */
  88 #endif  /* ENCRYPTION */
  89     int         size;           /* size in bytes of buffer */
  90     u_long      consumetime,    /* help us keep straight full, empty, etc. */
  91                 supplytime;
  92 } Ring;
  93
  94 /* Here are some functions and macros to deal with the ring buffer */
  95
  96 /* Initialization routine */
  97 extern int
  98         ring_init P((Ring *ring, unsigned char *buffer, int count));
  99
 100 /* Data movement routines */
 101 extern void
 102         ring_supply_data P((Ring *ring, unsigned char *buffer, int count));
 103 #ifdef notdef
 104 extern void
 105         ring_consume_data P((Ring *ring, unsigned char *buffer, int count));
 106 #endif
 107
 108 /* Buffer state transition routines */
 109 extern void
 110         ring_supplied P((Ring *ring, int count)),
 111         ring_consumed P((Ring *ring, int count));
 112
 113 /* Buffer state query routines */
 114 extern int
 115         ring_empty_count P((Ring *ring)),
 116         ring_empty_consecutive P((Ring *ring)),
 117         ring_full_count P((Ring *ring)),
 118         ring_full_consecutive P((Ring *ring));
 119
 120 #ifdef  ENCRYPTION
 121 extern void
 122         ring_encrypt P((Ring *ring, void (*func)())),
 123         ring_clearto P((Ring *ring));
 124 #endif  /* ENCRYPTION */
 125
 126 extern void
 127     ring_clear_mark(),
 128     ring_mark();