Annotation of src/usr.bin/telnet/ring.h, Revision 1.1.1.1
1.1 deraadt 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: * from: @(#)ring.h 8.1 (Berkeley) 6/6/93
34: * $Id: ring.h,v 1.3 1994/02/25 03:00:36 cgd Exp $
35: */
36:
37: #if defined(P)
38: # undef P
39: #endif
40:
41: #if defined(__STDC__) || defined(LINT_ARGS)
42: # define P(x) x
43: #else
44: # define P(x) ()
45: #endif
46:
47: /*
48: * This defines a structure for a ring buffer.
49: *
50: * The circular buffer has two parts:
51: *(((
52: * full: [consume, supply)
53: * empty: [supply, consume)
54: *]]]
55: *
56: */
57: typedef struct {
58: unsigned char *consume, /* where data comes out of */
59: *supply, /* where data comes in to */
60: *bottom, /* lowest address in buffer */
61: *top, /* highest address+1 in buffer */
62: *mark; /* marker (user defined) */
63: int size; /* size in bytes of buffer */
64: u_long consumetime, /* help us keep straight full, empty, etc. */
65: supplytime;
66: } Ring;
67:
68: /* Here are some functions and macros to deal with the ring buffer */
69:
70: /* Initialization routine */
71: extern int
72: ring_init P((Ring *ring, unsigned char *buffer, int count));
73:
74: /* Data movement routines */
75: extern void
76: ring_supply_data P((Ring *ring, unsigned char *buffer, int count));
77: #ifdef notdef
78: extern void
79: ring_consume_data P((Ring *ring, unsigned char *buffer, int count));
80: #endif
81:
82: /* Buffer state transition routines */
83: extern void
84: ring_supplied P((Ring *ring, int count)),
85: ring_consumed P((Ring *ring, int count));
86:
87: /* Buffer state query routines */
88: extern int
89: ring_empty_count P((Ring *ring)),
90: ring_empty_consecutive P((Ring *ring)),
91: ring_full_count P((Ring *ring)),
92: ring_full_consecutive P((Ring *ring));
93:
94:
95: extern void
96: ring_clear_mark(),
97: ring_mark();