hash.H

Go to the documentation of this file.

#ifndef HASH_NODE_INCLUDED
#define HASH_NODE_INCLUDED


class hash_node {
    private:
   long       _key;
   void      *_data;
   hash_node *_next;
    public:
        hash_node(long key, void *value, hash_node *next)
       {_key = key; _data = value; _next = next;}
   hash_node(const hash_node &old)
       {_key = old._key; _data = old._data;
        _next = old._next ? new hash_node(*old._next) : 0;}
        hash_node() {_key = 0; _data = 0; _next = 0;}
      hash_node *next() const       {return _next;}
      void       next(hash_node *n) {_next = n;}
      void      *data() const       {return _data;}
      void      *&data_ptr()        {return _data;}
      long       key()  const       {return _key;}
      void       data(void *data)   {_data = data;}
};

#define CHASH const HASH
template <class T>
class ARRAY;

class HASH {
    private:
   int         _size;
        hash_node **_table;
   int         _mask;
   int         _seq_val;
   hash_node **table() const {return _table;}
   int         _lastval;
   int  hash(const long key) const;
   long hash(const char *) const;
        // Returns 0 if done
   int    next_seq(long &key, void *&data, hash_node *&seq_elt,
                        int &seq_val) const;
    public:
      HASH(int size);
   HASH(const HASH &hash_table);
   ~HASH();
   void clear();
   // Add - returns 0 if doesn't already exist, 1 if it does
   int    add(long key, void *data);
   int    add(const char *key, void *data) {char *tmp; return add(key, data, tmp, 0);}
   int    add(const char *key, void *data, char *&loc, int create_new=1);
   int    add(const char *key, char *&loc) {return add(key, (void *) _lastval++, loc);}
   int    del(long key);
   void  *find(long key) const {void **data = find_addr(key); return data ? *data : 0;}
   void  *find(char *key) const;
   void **find_addr(long key) const;
   int    bfind(long key, void *&data) const;

        void   get_items(ARRAY<long> &keys, ARRAY<void *> &data) const;

        double load_factor() const; // avg number of elements per slot
};
#endif

---