ring.c

//
// ring.c -- Ring buffers
//
//  Copyright (c) 2012-2013 Andrew Payne <andy@payne.org>
//

#include <freedom.h>
#include "common.h"

inline void buf_reset(RingBuffer *buf, int size)
{
    buf->head = buf->tail = 0;
    buf->size = size;
}

inline int buf_len(RingBuffer *buf)
{
    int len = buf->tail - buf->head;
    if (len < 0)
        len += buf->size;
    
    return len;
}

inline int buf_isfull(RingBuffer *buf)
{
    return buf_len(buf) == (buf->size-1);
}

inline int buf_isempty(RingBuffer *buf)
{
    return buf->head == buf->tail;
}

inline uint8_t buf_get_byte(RingBuffer *buf)
{
    uint8_t item;
    
    item = buf->data[buf->head++];
    if (buf->head == buf->size)         // Wrap
        buf->head = 0;
        
    return item;
}

inline void buf_put_byte(RingBuffer *buf, uint8_t val)
{
    buf->data[buf->tail++] = val;
    if (buf->tail == buf->size)
        buf->tail = 0;
}

#ifdef OMIT
inline int buf_get(RingBuffer *buf, uint8_t *out, int maxlen)
{
    int len = min(buf_len(buf), maxlen);
    int chunk, rlen;
    
    rlen = len;
    while (rlen) {
        chunk = buf->tail - buf->head;
        if(chunk < 0)
            chunk = buf->size - buf->head;

        memcpy(out, buf->data + buf->head, chunk);
        out += chunk;
        rlen -= chunk;
        buf->head += chunk;
        if(buf->head == buf->size)
            buf->head = 0;
    }
    return len;
}

inline int buf_put(RingBuffer *buf, uint8_t *in, int len)
{
        
}
#endif