hashtable.c


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#include <stdlib.h>
#include "hashtable.h"

const unsigned int fnvPrime = 16777619;
const unsigned int fnvOffset = 2166136261U;

//FNV-1a hash
unsigned int get_hash(char* str) {
	unsigned int hash = fnvOffset;
	while (*str != '\0') {
		hash = (hash ^ *str) * fnvPrime;
		str++;
	}
	return hash;
}
hashtable_t* init_hashtable(unsigned int capacity) {
	hashtable_t* ht = malloc(sizeof(hashtable_t));
	ht->pairs = calloc(capacity, sizeof(pair_t*));
	ht->capacity = capacity;
	return ht;
}
/* TODO: handle collision
TODO: return 0 if something goes wrong */
unsigned int hashtable_add_pair(hashtable_t* hashtable, pair_t pair) {
	unsigned int hash = get_hash(pair.key);
	pair_t* memPair = malloc(sizeof(pair_t));
	*memPair = pair;
	hashtable->pairs[hash % hashtable->capacity] = memPair;
	return hash;
}
pair_t* hashtable_get_pair(hashtable_t* hashtable, char* key) {
	unsigned int hash = get_hash(key);
	return hashtable->pairs[hash % hashtable->capacity];
}