1.0 KiB
Hash Table
Well, the moment has come. I never made a Hash Map algorithm, but in this scenario I have to save both fd and sockaddr (I could make a simply linked list, but it's a way to learn new things).
Let's start with a little bit of theory.
A Hash Table is a data structure also called dictionary or map. It maps keys to values thanks to a hash function that computes and index (hash code) into an array of buckets.
One problem could be the hash collision where the hash function computes the same index for different values. A fix could be the chaining method, where for the same hash code you can make a linked list and append the index. Then the lookup function will go through the list and find the key.
In a Hash Map you can insert, delete and lookup (simply search).
Hash function
The easiest way... don't judge me.
- Integer keys:
hash(\text{key}) = \text{key} \mod \text{table\_dim}
- String keys:
hash(key) = \sum_{i=0}^{len(key) - 1} ascii\_value(key[i]) * prime\_number