struct hash_table_entry *array;
};
-extern void *lookup_hash(unsigned int hash, struct hash_table *table);
+extern void *lookup_hash(unsigned int hash, const struct hash_table *table);
extern void **insert_hash(unsigned int hash, void *ptr, struct hash_table *table);
-extern int for_each_hash(struct hash_table *table, int (*fn)(void *));
+extern int for_each_hash(const struct hash_table *table, int (*fn)(void *, void *), void *data);
extern void free_hash(struct hash_table *table);
static inline void init_hash(struct hash_table *table)