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