goldsborough/hashtable

A pure C hashtable implementation.

hashtable

hashtable is a feature-complete, generic and customizable separate-chaining hashtable in pure C.

Usage

#include "hashtable.h"

int main(int argc, const char* argv[]) {
	HashTable table;

	/* Choose initial capacity of 10 */
	/* Specify the size of the keys and values you want to store once */
	ht_setup(&table, sizeof(int), sizeof(double), 10);

	ht_reserve(&table, 100);

	int x = 6;
	double y = 9;
	ht_insert(&table, &x, &y);

	if (ht_contains(&table, &x)) {
		y = *(double*)ht_lookup(&table, &x);
		/* Or use convenience macros */
		y = HT_LOOKUP_AS(double, &table, &x);
		printf("%d's value is: %f\n", x, y);
	}

	ht_erase(&table, &x);

	ht_clear(&table);
	ht_destroy(&table);
}

License

This project is released under the MIT License. For more information, see the LICENSE file.

Authors

Peter Goldsborough + cat ❤️

hashtable's Issues

Is this a bug?

   double y = 290; 
   ht_insert(&table, "HELL", &y);
   double* k = (double*)ht_lookup(&table, "HELLO");
   if (k)
            printf("[%s]'s value is: [%f]\n", "HELLO", *k);
    else
            printf("[%s] NOT FOUND!\n", "HELLO");

=====================
[HELLO]'s value is: [290.000000]

HT_SHRINK_THRESHOLD is 0

HT_SHRINK_THRESHOLD is defined as (1/4), which is 0 (because of int division). This means that _ht_should_shrink will return true if and only if the size (table->size) is 0. This doesn't seem like intended behavior.

How do we iterate through this hash table?

"... hashtable is a feature-complete, generic and customizable separate-chaining hashtable in pure C...."

How do we iterate through this hash table?

QUESTIONS: thread-safe operations?

1. Are ht_contains(..) and ht_lookup(..) thread-safe where they can be called in the child threads simultaneously?
2. What's the difference between ht_setup(...) and ht_reserve(...)? Is ht_reserve an optional function?