111 lines
2.3 KiB
C
111 lines
2.3 KiB
C
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/*
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* (C) Copyright 2003
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* Gerry Hamel, geh@ti.com, Texas Instruments
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <common.h>
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#include <malloc.h>
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#include <circbuf.h>
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int buf_init (circbuf_t * buf, unsigned int size)
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{
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assert (buf != NULL);
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buf->size = 0;
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buf->totalsize = size;
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buf->data = (char *) malloc (sizeof (char) * size);
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assert (buf->data != NULL);
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buf->top = buf->data;
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buf->tail = buf->data;
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buf->end = &(buf->data[size]);
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return 1;
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}
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int buf_free (circbuf_t * buf)
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{
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assert (buf != NULL);
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assert (buf->data != NULL);
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free (buf->data);
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memset (buf, 0, sizeof (circbuf_t));
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return 1;
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}
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int buf_pop (circbuf_t * buf, char *dest, unsigned int len)
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{
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unsigned int i;
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char *p = buf->top;
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assert (buf != NULL);
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assert (dest != NULL);
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/* Cap to number of bytes in buffer */
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if (len > buf->size)
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len = buf->size;
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for (i = 0; i < len; i++) {
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dest[i] = *p++;
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/* Bounds check. */
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if (p == buf->end) {
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p = buf->data;
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}
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}
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/* Update 'top' pointer */
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buf->top = p;
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buf->size -= len;
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return len;
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}
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int buf_push (circbuf_t * buf, const char *src, unsigned int len)
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{
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/* NOTE: this function allows push to overwrite old data. */
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unsigned int i;
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char *p = buf->tail;
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assert (buf != NULL);
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assert (src != NULL);
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for (i = 0; i < len; i++) {
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*p++ = src[i];
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if (p == buf->end) {
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p = buf->data;
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}
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/* Make sure pushing too much data just replaces old data */
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if (buf->size < buf->totalsize) {
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buf->size++;
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} else {
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buf->top++;
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if (buf->top == buf->end) {
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buf->top = buf->data;
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}
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}
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}
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/* Update 'tail' pointer */
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buf->tail = p;
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return len;
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}
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