Thread: Hash implementations

Hi all,

I am looking for a hash written in C that meets the following needs:

* the size of the hash, n, is known and fixed before initialization, and n is large;
* only init_hash(), hash_add() and hash_get() are needed;
* keys are char pointers and values and struct pointers;
* the hash table takes up small number of memory size.

My most important requirement is that the hash table does not take up a lot of memory, in the case that a lot of extra memory are allocated.

Do you have any pointer to such hash implementation?

Thank you!

STL is for C++, not C.

You don't feel like writing your own?

The Wikipedia article for "hash table" lists a few hash implementations.

Originally Posted by SoFarAway

Hi all,
My most important requirement is that the hash table does not take up a lot of memory, in the case that a lot of extra memory are allocated.

You can make the hash table size any size you want. It's purely a tradeoff between memory usage and speed. However if you don't use seperate chaining then your hash table must be big enough to hold all items, and ideally capable of holding perhaps twice as many items.

I personally swear by the use of CRC as the preferred hashing algorithm in every circumstance.