// Larbin// Sebastien Ailleret// 09-11-99 -> 01-12-01/* standard fifo in RAM WITHOUT synchronisation */#ifndef FIFO_H#define FIFO_Htemplate <class T>class Fifo { public:  uint in, out;  uint size;  T **tab;  /* Specific constructor */  Fifo (uint size=maxUrlsBySite);  /* Destructor */  ~Fifo ();  /* give the first object and let it in */  inline T* read () { return tab[out]; }  /* read the first obj if exist */  T *tryRead ();  /* get the first object */  T *get ();  /* get the first object (non totally blocking)   * return NULL if there is none   */  T *tryGet ();  /* add an object in the Fifo */  void put (T *obj);  /* put an obj that has just been get   * this function must be called only to put back an obj   *    that has just been tken with get */  void rePut (T *obj);  /* how many items are there inside ? */  int getLength ();  /* is this fifo empty ? */  inline bool isEmpty () { return in == out; }};template <class T>Fifo<T>::Fifo (uint size) {  tab = new T*[size];  this->size = size;  in = 0;  out = 0;}template <class T>Fifo<T>::~Fifo () {  delete [] tab;}template <class T>T *Fifo<T>::tryRead () {  if (in == out) {    return NULL;  } else {    return tab[out];  }}template <class T>T *Fifo<T>::get () {  T *tmp;  assert (in != out);  tmp = tab[out];  out = (out + 1) % size;  return tmp;}template <class T>T *Fifo<T>::tryGet () {  T *tmp = NULL;  if (in != out) {	// The stack is not empty	tmp = tab[out];	out = (out + 1) % size;  }  return tmp;}template <class T>void Fifo<T>::put (T *obj) {  tab[in] = obj;  in = (in + 1) % size;  if (in == out) {    T **tmp;    tmp = new T*[2*size];    for (uint i=out; i<size; i++) {      tmp[i] = tab[i];    }    for (uint i=0; i<in; i++) {      tmp[i+size] = tab[i];    }    in += size;    size *= 2;    delete [] tab;    tab = tmp;  }}template <class T>void Fifo<T>::rePut (T *obj) {  out = (out + size - 1) % size;  tab[out] = obj;}template <class T>int Fifo<T>::getLength () {  return (in + size - out) % size;}#endif // FIFO_H