#include "fifo.h"

using namespace std;

//#define DEBUGFIFO

////////////////////////////////////////////
Fifo::Fifo(unsigned int f_size)
{
    cout << "construction d'une fifo" << endl;
    this->data=new char(f_size);    //allocation de data
    this->fifo_size = f_size ;
    this->write_index = 0 ;
    this->read_index = 0 ;
    this->nb_available = 0 ;
}
////////////////////////////////////////////
Fifo::~Fifo()
{
    delete(this->data);    //libération de data
}
////////////////////////////////////////////
char Fifo::write_char(const char token){
    if(this->nb_available >= this->fifo_size) return 0 ;
    this->data[this->write_index] = token ;
    this->write_index = this->write_index + 1;
    if(this->write_index >= this->fifo_size) this->write_index = 0 ;
    this->nb_available = this->nb_available + 1 ;
    return 1 ;
}
////////////////////////////////////////////
char Fifo::read_char(char * token){
    if(this->nb_available == 0) return 0;
    *token = this->data[this->read_index]  ;
    this->read_index = this->read_index + 1;
    if(this->read_index >= this->fifo_size) this->read_index = 0 ;
    this->nb_available = this->nb_available -1 ;
    return 1 ;
}
////////////////////////////////////////////
int Fifo::get_nb_available() {
#ifdef DEBUGFIFO
    cout <<" get_nb_available() a été invoquée"<<endl;
#endif
    return  this->nb_available;
}