kernel/ringbuffer.c


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#include "ringbuffer.h"
#include "kmalloc.h"
#include "log.h"

ringbuffer ringbuffer_init(uint32_t size)
{
    ringbuffer f;
    f.data=kballoc(size);
    f.size=size*4096;
    f.head=0;
    f.tail=0;
    return f;
}

void ringbuffer_free(ringbuffer *f)
{
    kbfree(f->data);
}

bool ringbuffer_full(ringbuffer* f)
{
    return((f->tail+1)%f->size==f->head);
}

bool ringbuffer_not_full(ringbuffer* f)
{
    return((f->tail+1)%f->size!=f->head);
}

bool ringbuffer_empty(ringbuffer* f)
{
    return(f->head==f->tail);
}

bool ringbuffer_has(ringbuffer* f)
{
    return(f->head!=f->tail);
}

bool ringbuffer_put(ringbuffer* f,uint8_t c)
{
    if(ringbuffer_full(f))
    {
#ifdef LOG_RINGBUFFER_WARN
        klog("ringbuffer is full!");
#endif
        return false; 
    }

    f->data[f->tail]=c;
    f->tail=(f->tail+1)%f->size;
    return true;
}

uint8_t ringbuffer_get(ringbuffer* f)
{
    if(ringbuffer_empty(f))
    {
#ifdef LOG_RINGBUFFER_WARN
        klog("ringbuffer is empty!");
#endif
        return 0;  //  indistinguishable from byte value 0x00.
    }

    uint8_t c = f->data[f->head];
    f->head=(f->head+1)%f->size;
    return c;
}

// TODO //

uint32_t ringbuffer_write(ringbuffer* f, uint8_t *buf, uint32_t size)
{
    return 0;
}

uint32_t ringbuffer_read(ringbuffer* f, uint8_t *buf, uint32_t size)
{
    return 0;
}