htlib: A Lightweight C Hashmap Library

Overview

htlib is a lightweight, cross-platform C library that provides a simple and efficient hashmap implementation. It supports various key and value types, including integers, unsigned integers, doubles, strings, and pointers, making it suitable for a wide range of applications.

Features

Attention

The library is not ready. It is still missing features for automatic resizing and there is an issue with tables using integer keys and string values.

• Support for various key and value types:
  • Signed/unsigned integers
  • Doubles
  • C strings
  • Pointers to custom data structures
• No external dependencies: htlib relies only on standard C libraries, ensuring portability across different platforms.
• Efficient hash function: Uses the FNV-1a hash algorithm for good distribution and performance.
• Collision handling: Implements separate chaining for efficient handling of collisions.
• Dynamic resizing: Automatically resizes the hashmap as needed to maintain performance. (To be implemented)
• Memory management: Provides functions for clearing and destroying the hashmap, ensuring proper memory deallocation.

Example Operations

Including the library

#include "htlib.h"

Creating a hashmap

ht_hashmap_t *ht = ht_new(HT_KEY_TYPE_INT, HT_VALUE_TYPE_STRING, 16);

This creates a new hashmap with an initial capacity of 16. The key type is set to HT_KEY_TYPE_INT, and the value type is set to HT_VALUE_TYPE_STRING.

Inserting key-value pairs

int key = 1;
const char *value = "value1";
ht_insert(ht, &key, value);

Retrieving values

char retrieved_value[100];
ht_get(ht, &key, retrieved_value);

Removing key-value pairs

ht_remove(ht, &key);

Other operations

• ht_size(ht): Returns the number of elements in the hashmap.
• ht_is_empty(ht): Checks if the hashmap is empty.
• ht_clear(ht): Removes all elements from the hashmap.
• ht_destroy(ht): Destroys the hashmap and frees the allocated memory.