93 lines
1.7 KiB
C
93 lines
1.7 KiB
C
#ifndef CIRCBUF_H
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#define CIRCBUF_H
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#include <stdio.h>
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#include <stdint.h>
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struct circbuf {
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int16_t *data;
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uint32_t read;
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uint32_t write;
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unsigned int len;
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};
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struct circbuf *circbuf_make(size_t size, unsigned int len);
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struct circbuf circbuf_init(size_t size, unsigned int len);
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void cbuf_push(struct circbuf *buf, short data);
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short cbuf_shift(struct circbuf *buf);
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#endif
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#ifdef CBUF_IMPLEMENT
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#include "assert.h"
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#include "stdlib.h"
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unsigned int powof2(unsigned int num)
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{
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if (num != 0) {
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num--;
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num |= (num >> 1);
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num |= (num >> 2);
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num |= (num >> 4);
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num |= (num >> 8);
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num |= (num >> 16);
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num++;
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}
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return num;
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}
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int ispow2(int num)
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{
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return (num && !(num & (num - 1)));
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}
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struct circbuf *circbuf_make(size_t size, unsigned int len)
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{
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struct circbuf *new = malloc(sizeof(*new));
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new->len = powof2(len);
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new->data = calloc(sizeof(short), new->len);
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new->read = new->write = 0;
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return new;
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}
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struct circbuf circbuf_init(size_t size, unsigned int len)
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{
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struct circbuf new;
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new.len = powof2(len);
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new.data = calloc(sizeof(short), new.len);
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new.read = new.write = 0;
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return new;
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}
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int cbuf_size(struct circbuf *buf) {
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return buf->write - buf->read;
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}
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int cbuf_empty(struct circbuf *buf) {
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return buf->read == buf->write;
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}
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int cbuf_full(struct circbuf *buf) {
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return cbuf_size(buf) >= buf->len;
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}
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uint32_t cbuf_mask(struct circbuf *buf, uint32_t n) {
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return n & (buf->len-1);
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}
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void cbuf_push(struct circbuf *buf, short data) {
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//assert(!cbuf_full(buf));
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buf->data[cbuf_mask(buf,buf->write++)] = data;
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}
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short cbuf_shift(struct circbuf *buf) {
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//assert(!cbuf_empty(buf));
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return buf->data[cbuf_mask(buf, buf->read++)];
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}
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#endif
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