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e2887563 JA |
1 | /* |
2 | * A simple FIFO implementation. | |
3 | * | |
4 | * Copyright (C) 2004 Stelian Pop <stelian@popies.net> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | * | |
20 | */ | |
21 | struct fifo { | |
22 | unsigned char *buffer; /* the buffer holding the data */ | |
23 | unsigned int size; /* the size of the allocated buffer */ | |
24 | unsigned int in; /* data is added at offset (in % size) */ | |
25 | unsigned int out; /* data is extracted from off. (out % size) */ | |
26 | }; | |
27 | ||
28 | struct fifo *fifo_alloc(unsigned int); | |
29 | unsigned int fifo_put(struct fifo *, void *, unsigned int); | |
30 | unsigned int fifo_get(struct fifo *, void *, unsigned int); | |
38470f85 | 31 | void fifo_free(struct fifo *); |
e2887563 JA |
32 | |
33 | static inline unsigned int fifo_len(struct fifo *fifo) | |
34 | { | |
35 | return fifo->in - fifo->out; | |
36 | } | |
37 | ||
104bc4bd JA |
38 | static inline unsigned int fifo_room(struct fifo *fifo) |
39 | { | |
40 | return fifo->size - fifo->in + fifo->out; | |
41 | } | |
42 | ||
e2887563 JA |
43 | #define min(x,y) ({ \ |
44 | typeof(x) _x = (x); \ | |
45 | typeof(y) _y = (y); \ | |
46 | (void) (&_x == &_y); \ | |
47 | _x < _y ? _x : _y; }) | |
48 | ||
49 | #define max(x,y) ({ \ | |
50 | typeof(x) _x = (x); \ | |
51 | typeof(y) _y = (y); \ | |
52 | (void) (&_x == &_y); \ | |
53 | _x > _y ? _x : _y; }) | |
54 |