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 } 111