Dictionary from Redis

dict.h

// dict.h

typedef struct dictEntry {
    void *key;
    void *val;
    struct dictEntry *next;
} dictEntry;

typedef struct dictht {
    dictEntry **table;
    unsigned long size;
    unsigned long sizemask;
    unsigned long used;
} dictht;

typedef struct dict {
    void *privdata;
    dictht ht[2];    
    int rehashidx; 
    int iterators; 
} dict;


typedef struct dictType {
    unsigned int (*hashFunction)(const void *key);                          // And what this line does??
    void *(*keyDup)(void *privdata, const void *key);                       // And this?
    void *(*valDup)(void *privdata, const void *obj);                       // And this?
    int (*keyCompare)(void *privdata, const void *key1, const void *key2);  // And this?
    void (*keyDestructor)(void *privdata, void *key);                       // And this?
    void (*valDestructor)(void *privdata, void *obj);                       // And this?
} dictType;

How I access the entries(key and value) from the first dictht?

dict my_dict;

 my_dict.ht[0].table[0]->key   // ??
 my_dict.ht[0].table[0]->value   // ??

I reading three guides about pointers to pointers and I don't understand How I access this??