#define FOOLOS_MODULE_NAME "fifo"
#include "lib/logger/log.h"

#include "fifo.h"

static int sl=9;

fifo fifo_init(uint32_t size)
{
    fifo f;
    f.data=kballoc(size);
    f.size=size*4096;
    f.front=f.size-1;
    f.back=f.size-1;
    return f;
}

bool fifo_put(fifo* f,uint8_t c)
{
    x86_int_disable();
    lock_spin(sl);

    if((f->back-1+f->size)%f->size==f->front)
    {
	lock_release(sl);
	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"unlocked by put");
	x86_int_enable();
	return false;
    }

    f->data[f->back]=c;
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"put %d %d (%c)", f->back, f->front,c);
    f->back--;
    f->back+=f->size;
    f->back%=f->size;

    lock_release(sl);
    x86_int_enable();
    
    return true;
}

uint8_t fifo_get(fifo* f)	    // blocking
{

    char c;

    x86_int_disable();
    lock_spin(sl);

    if(f->front==f->back)
    {
	lock_release(sl);
	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"unlocked by get");
	x86_int_enable();
	c='_';
	return false;
    }

    c=f->data[f->front];
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"get %d %d (%c)", f->back, f->front,c);

    f->front--;
    f->front+=f->size;
    f->front%=f->size;

    lock_release(sl);
    x86_int_enable();

    return true;
}