hash_map_c

Naive and portable implementation of a hash map (view) written in C99, using the FNV1a hash function.
Made as an exercise and for personal use in hobby projects.

This implementation only holds pointers to key and value pairs; no copying occurs, therefore it is the user's responsibility to maintain the data.
Collisions are handled with linear probing, for the sake of simplicity and locality(?).
No removal implemented, to be considered.

Opaque macro version for ease-of-use

#include <stdio.h>
#include <string.h>
#include "hash_map.h"

int main(void)
{
	struct hash_map map;
	struct hash_map_iter iter;
	/* Data */
	const char *strings[] = {"alpha", "beta", "gamma", "epsilon", "delta"};
	int nums[] = {83, 2, 3, 4, 5};
	/* Data accessors */
	char *key;
	void *val;

	HASH_MAP_INIT(&map, HASH_MAP_KEY_TYPE_STRING);
	HASH_MAP_INSERT(&map, strings[0], strlen(strings[0]) + 1, &nums[0],
		sizeof(nums[0]));
	HASH_MAP_INSERT(&map, strings[0], strlen(strings[0]) + 1, &nums[0],
		sizeof(nums[0]));
	HASH_MAP_INSERT(&map, strings[1], strlen(strings[1]) + 1, &nums[1],
		sizeof(nums[1]));
	HASH_MAP_INSERT(&map, strings[2], strlen(strings[2]) + 1, &nums[2],
		sizeof(nums[2]));
	HASH_MAP_INSERT(&map, strings[3], strlen(strings[3]) + 1, &nums[3],
		sizeof(nums[3]));
	HASH_MAP_INSERT(&map, strings[4], strlen(strings[4]) + 1, &nums[4],
		sizeof(nums[4]));
	hash_map_iter_init(&iter, &map);
	HASH_MAP_ITER_FOR_EACH(&iter, key, val) {
		printf("%s : %d\n", key, *(int *)val);
	}
	hash_map_iter_finish(&iter);
	hash_map_finish(&map);
	return 0;
}

Explicit function version

#include <stdio.h>
#include <string.h>
#include "hash_map.h"

int main(void)
{
	/* TODO */
}