1/*-
2 * Copyright (c) 2003 Mathew Kanner
3 * 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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#ifndef MIDIQ_H
30#define MIDIQ_H
31
32#define MIDIQ_MOVE(a,b,c) bcopy(b,a,c)
33
34#define MIDIQ_HEAD(name, type)          \
35struct name {                           \
36        int h, t, s;                    \
37        type * b;                        \
38}
39
40#define MIDIQ_INIT(head, buf, size) do {                \
41        (head).h=(head).t=0;                          \
42        (head).s=size;                                 \
43        (head).b=buf;                                  \
44} while (0)
45
46#define MIDIQ_EMPTY(head)       ((head).h == (head).t )
47
48#define MIDIQ_LENBASE(head)         ((head).h - (head).t < 0 ? \
49                                        (head).h - (head).t + (head).s : \
50                                        (head).h - (head).t)
51
52#define MIDIQ_FULL(head)        ((head).h == -1)
53#define MIDIQ_AVAIL(head)       (MIDIQ_FULL(head) ? 0 : (head).s - MIDIQ_LENBASE(head))
54#define MIDIQ_LEN(head)		((head).s - MIDIQ_AVAIL(head))
55#define MIDIQ_DEBUG 0
56/*
57 * No protection against overflow, underflow
58 */
59#define MIDIQ_ENQ(head, buf, size) do {                                                                 \
60		if(MIDIQ_DEBUG)\
61                	printf("#1 %p %p bytes copied %jd tran req s %d h %d t %d\n",            \
62			       &(head).b[(head).h], (buf),                                        \
63			       (intmax_t)(sizeof(*(head).b) *                                     \
64					  MIN( (size), (head).s - (head).h) ),                   \
65			       (size), (head).h, (head).t);               \
66                MIDIQ_MOVE(&(head).b[(head).h], (buf), sizeof(*(head).b) * MIN((size), (head).s - (head).h));                       \
67                if( (head).s - (head).h < (size) ) {                                                    \
68			if(MIDIQ_DEBUG) \
69                        	printf("#2 %p %p bytes copied %jd\n",  (head).b, (buf) + (head).s - (head).h, (intmax_t)sizeof(*(head).b) * ((size) - (head).s + (head).h) );      \
70                        MIDIQ_MOVE((head).b, (buf) + (head).s - (head).h, sizeof(*(head).b) * ((size) - (head).s + (head).h) );      \
71		} \
72                (head).h+=(size);                                                                         \
73                (head).h%=(head).s;                                                                     \
74		if(MIDIQ_EMPTY(head)) (head).h=-1; \
75		if(MIDIQ_DEBUG)\
76                	printf("#E h %d t %d\n", (head).h, (head).t);                       \
77} while (0)
78
79#define MIDIQ_DEQ_I(head, buf, size, move, update) do {                                                                 \
80		if(MIDIQ_FULL(head)) (head).h=(head).t; \
81		if(MIDIQ_DEBUG)\
82                	printf("#1 %p %p bytes copied %jd tran req s %d h %d t %d\n", &(head).b[(head).t], (buf), (intmax_t)sizeof(*(head).b) * MIN((size), (head).s - (head).t), (size), (head).h, (head).t);                       \
83                if (move) MIDIQ_MOVE((buf), &(head).b[(head).t], sizeof(*(head).b) * MIN((size), (head).s - (head).t));                       \
84                if( (head).s - (head).t < (size) ) {                                                    \
85			if(MIDIQ_DEBUG) \
86                        	printf("#2 %p %p bytes copied %jd\n",  (head).b, (buf) + (head).s - (head).t, (intmax_t)sizeof(*(head).b) * ((size) - (head).s + (head).t) );      \
87                        if (move) MIDIQ_MOVE((buf) + (head).s - (head).t, (head).b, sizeof(*(head).b) * ((size) - (head).s + (head).t) );      \
88		} \
89		if (update) { \
90                (head).t+=(size);                                                                         \
91                (head).t%=(head).s;                                                                     \
92		} else { \
93		  if (MIDIQ_EMPTY(head)) (head).h=-1; \
94		} \
95		if(MIDIQ_DEBUG)\
96                	printf("#E h %d t %d\n", (head).h, (head).t);                       \
97} while (0)
98
99#define MIDIQ_SIZE(head) ((head).s)
100#define MIDIQ_CLEAR(head) ((head).h = (head).t = 0)
101#define MIDIQ_BUF(head) ((head).b)
102#define MIDIQ_DEQ(head, buf, size) MIDIQ_DEQ_I(head, buf, size, 1, 1)
103#define MIDIQ_PEEK(head, buf, size) MIDIQ_DEQ_I(head, buf, size, 1, 0)
104#define MIDIQ_POP(head, size) MIDIQ_DEQ_I(head, &head, size, 0, 1)
105
106#endif
107