supike / crbhashmap

crbhashmap is a lightweight hash map implementation in C language.

crbhashmap

crbhashmap is a lightweight hash map implementation in C language. This project utilizes the Robin Hood hashing algorithm to support efficient key-value storage and retrieval. Robin Hood hashing minimizes key movement during insertion using linear probing, thereby enhancing search performance.

Features

• Dynamic Resizing: Automatically expands capacity when the load factor exceeds a predefined threshold.
• Hashing Algorithm: Uses the XXH64 hash function for key hashing.
• Iterators: Supports iterators for easy traversal of stored elements.
• Memory Management: Provides options for managing values stored in the hash map.

Usage

1. Prerequisites:

   • C compiler (e.g., GCC)
   • Standard C libraries (stdio.h, stdlib.h, string.h)

2. Installation:

   • Clone the repository: git clone https://github.com/ultracpp/crbhashmap
   • Navigate to the directory: cd c-rb-hash-map

3. Integration:

   • Include "crbhashmap.h" in your source files.
   • Link with "xxhash.c", "crbhashmap.c" during compilation.

4. Example:

    #include <stdio.h>
    #include "clib.h"
    #include "crbhashmap.h"
   
    void* Create_int()
    {
    	return INT_TO_POINTER(0);
    }
   
    int main()
    {
    	// Example usage
    	int test_count = 100;
   
    	c_rb_hash_map cmap = {};
    	c_rb_hash_map_init(&cmap, -1, 0, &Create_int);
   
    	for (int i = 0, j = test_count; i < j; i++)
    	{
    		char* key = (char*)malloc(8);
    		sprintf(key, "%d", i);
   
    		c_rb_hash_map_insert(&cmap, key, INT_TO_POINTER(i));
    		free(key);
    	}
   
    	printf("====insert, size:%d\n", cmap.count);
   
    	c_rb_hash_iter citer;
    	c_rb_hash_iter_init(&citer, &cmap);
    	char* __key = NULL;
    	void* __value = NULL;
   
    	while (c_rb_hash_iter_next(&citer, &__key, &__value))
    	{
    		int val = POINTER_TO_INT(__value);
    		printf("%s, %d\n", __key, val);
    	}
   
    	printf("====iterate, size:%d\n", cmap.count);
   
    	for (int i = 0, j = test_count; i < j; i++)
    	{
    		char* key = (char*)malloc(8);
    		sprintf(key, "%d", i + 2);
   
    		c_rb_hash_node* pnode = c_rb_hash_map_insert_or_find(&cmap, key);
    		printf("%s, %d\n", key, POINTER_TO_INT(pnode->value));
   
    		free(key);
    	}
   
    	printf("====insert_or_find, size:%d\n", cmap.count);
   
    	c_rb_hash_iter_init(&citer, &cmap);
   
    	while (c_rb_hash_iter_next(&citer, &__key, &__value))
    	{
    		int val = POINTER_TO_INT(__value);
    		printf("%s, %d\n", __key, val);
    	}
   
    	printf("====iterate, size:%d\n", cmap.count);
   
    	char* key = (char*)malloc(8);
   
    	for (int i = 0, j = test_count + 4; i < j; i++)
    	{
    		sprintf(key, "%d", i);
   
    		c_rb_hash_node* pnode = c_rb_hash_map_find(&cmap, key);
   
    		if (pnode != NULL)
    		{
    			int val = POINTER_TO_INT(pnode->value);
    			printf("contains, %s=%d\n", key, val);
    		}
    		else
    		{
    			printf("====not found, %s\n", key);
    		}
   
    		c_rb_hash_map_remove(&cmap, key);
    	}
   
    	free(key);
   
    	printf("====remove size:%d\n", cmap.count);
   
    	c_rb_hash_map cmap2 = {};
    	c_rb_hash_map_move(&cmap2, &cmap);
    	printf("====move\n");
   
    	c_rb_hash_map_insert(&cmap, "test", INT_TO_POINTER(111));
   
    	c_rb_hash_iter_init(&citer, &cmap);
   
    	while (c_rb_hash_iter_next(&citer, &__key, &__value))
    	{
    		int val = POINTER_TO_INT(__value);
    		printf("cmap:%s, %d\n", __key, val);
    	}
   
    	c_rb_hash_map_destroy(&cmap);
   
    	c_rb_hash_iter_init(&citer, &cmap2);
   
    	while (c_rb_hash_iter_next(&citer, &__key, &__value))
    	{
    		int val = POINTER_TO_INT(__value);
    		printf("cmap2:%s, %d\n", __key, val);
    	}
   
    	c_rb_hash_map_destroy(&cmap2);
   
    	printf("====clear\n");
   
    	return 0;
    }

License

This project is licensed under the Apache License, Version 2.0. See the LICENSE file for details.