1/****************************************************************************
2 * Copyright 2020 Thomas E. Dickey                                          *
3 * Copyright 1998-2012,2016 Free Software Foundation, Inc.                  *
4 *                                                                          *
5 * Permission is hereby granted, free of charge, to any person obtaining a  *
6 * copy of this software and associated documentation files (the            *
7 * "Software"), to deal in the Software without restriction, including      *
8 * without limitation the rights to use, copy, modify, merge, publish,      *
9 * distribute, distribute with modifications, sublicense, and/or sell       *
10 * copies of the Software, and to permit persons to whom the Software is    *
11 * furnished to do so, subject to the following conditions:                 *
12 *                                                                          *
13 * The above copyright notice and this permission notice shall be included  *
14 * in all copies or substantial portions of the Software.                   *
15 *                                                                          *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23 *                                                                          *
24 * Except as contained in this notice, the name(s) of the above copyright   *
25 * holders shall not be used in advertising or otherwise to promote the     *
26 * sale, use or other dealings in this Software without prior written       *
27 * authorization.                                                           *
28 ****************************************************************************/
29
30/****************************************************************************
31 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
32 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
33 ****************************************************************************/
34
35/*
36 * Common macros for lib_getch.c, lib_ungetch.c
37 *
38 * $Id: fifo_defs.h,v 1.9 2020/02/02 23:34:34 tom Exp $
39 */
40
41#ifndef FIFO_DEFS_H
42#define FIFO_DEFS_H 1
43
44#define head	sp->_fifohead
45#define tail	sp->_fifotail
46/* peek points to next uninterpreted character */
47#define peek	sp->_fifopeek
48
49#define h_inc() { \
50	    (head >= FIFO_SIZE-1) \
51		? head = 0 \
52		: head++; \
53	    if (head == tail) \
54		head = -1, tail = 0; \
55	}
56#define h_dec() { \
57	    (head <= 0) \
58		? head = FIFO_SIZE-1 \
59		: head--; \
60	    if (head == tail) \
61		tail = -1; \
62	}
63#define t_inc() { \
64	    (tail >= FIFO_SIZE-1) \
65		? tail = 0 \
66		: tail++; \
67	    if (tail == head) \
68		tail = -1; \
69	    }
70#define t_dec() { \
71	    (tail <= 0) \
72		? tail = FIFO_SIZE-1 \
73		: tail--; \
74	    if (head == tail) \
75		fifo_clear(sp); \
76	    }
77#define p_inc() { \
78	    (peek >= FIFO_SIZE-1) \
79		? peek = 0 \
80		: peek++; \
81	    }
82
83#define cooked_key_in_fifo()	((head >= 0) && (peek != head))
84#define raw_key_in_fifo()	((head >= 0) && (peek != tail))
85
86#endif /* FIFO_DEFS_H */
87