| wdenk | 29e7f5a | 2004-03-12 00:14:09 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2003 |
| 3 | * Gerry Hamel, geh@ti.com, Texas Instruments |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include <common.h> |
| 22 | #include <malloc.h> |
| 23 | |
| 24 | #include <circbuf.h> |
| 25 | |
| 26 | |
| 27 | int buf_init (circbuf_t * buf, unsigned int size) |
| 28 | { |
| 29 | assert (buf != NULL); |
| 30 | |
| 31 | buf->size = 0; |
| 32 | buf->totalsize = size; |
| 33 | buf->data = (char *) malloc (sizeof (char) * size); |
| 34 | assert (buf->data != NULL); |
| 35 | |
| 36 | buf->top = buf->data; |
| 37 | buf->tail = buf->data; |
| 38 | buf->end = &(buf->data[size]); |
| 39 | |
| 40 | return 1; |
| 41 | } |
| 42 | |
| 43 | int buf_free (circbuf_t * buf) |
| 44 | { |
| 45 | assert (buf != NULL); |
| 46 | assert (buf->data != NULL); |
| 47 | |
| 48 | free (buf->data); |
| 49 | memset (buf, 0, sizeof (circbuf_t)); |
| 50 | |
| 51 | return 1; |
| 52 | } |
| 53 | |
| 54 | int buf_pop (circbuf_t * buf, char *dest, unsigned int len) |
| 55 | { |
| 56 | unsigned int i; |
| 57 | char *p = buf->top; |
| 58 | |
| 59 | assert (buf != NULL); |
| 60 | assert (dest != NULL); |
| 61 | |
| 62 | /* Cap to number of bytes in buffer */ |
| 63 | if (len > buf->size) |
| 64 | len = buf->size; |
| 65 | |
| 66 | for (i = 0; i < len; i++) { |
| 67 | dest[i] = *p++; |
| 68 | /* Bounds check. */ |
| 69 | if (p == buf->end) { |
| 70 | p = buf->data; |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | /* Update 'top' pointer */ |
| 75 | buf->top = p; |
| 76 | buf->size -= len; |
| 77 | |
| 78 | return len; |
| 79 | } |
| 80 | |
| 81 | int buf_push (circbuf_t * buf, const char *src, unsigned int len) |
| 82 | { |
| 83 | /* NOTE: this function allows push to overwrite old data. */ |
| 84 | unsigned int i; |
| 85 | char *p = buf->tail; |
| 86 | |
| 87 | assert (buf != NULL); |
| 88 | assert (src != NULL); |
| 89 | |
| 90 | for (i = 0; i < len; i++) { |
| 91 | *p++ = src[i]; |
| 92 | if (p == buf->end) { |
| 93 | p = buf->data; |
| 94 | } |
| 95 | /* Make sure pushing too much data just replaces old data */ |
| 96 | if (buf->size < buf->totalsize) { |
| 97 | buf->size++; |
| 98 | } else { |
| 99 | buf->top++; |
| 100 | if (buf->top == buf->end) { |
| 101 | buf->top = buf->data; |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | /* Update 'tail' pointer */ |
| 107 | buf->tail = p; |
| 108 | |
| 109 | return len; |
| 110 | } |