C语言 uthash哈希使用范例

#include "uthash.h"
#include <stdio.h>
#include <stdlib.h>
/*这个uthash必须构造一个结构体*/
struct packet
{
	int key;            /*这个是用来做hash的key值*/
	char msg[10]; 
	UT_hash_handle hh; /*这个结构是uthash的结构体，里面包含next，prev，hash值等信息*/
};

int main()
{
	struct packet *pkt, *tmp;
	int i;
	struct packet *hash_packet = NULL; /*必须初始化为NULL*/

	/*打印这个hash的节点数*/
	printf ("hash count = %d \n", HASH_COUNT(hash_packet));

	/*往hash中添加节点*/
	for (i=0; i<10; i++)
	{
		pkt = (struct packet *)malloc(sizeof(struct packet));
		pkt->key = i;
		sprintf (pkt->msg, "i=%d", i);

		HASH_FIND_INT(hash_packet, &i, tmp);
		if (tmp != NULL)
		{
			printf ("The key(%d) exists in hash. \n", i);
			continue;
		}
		HASH_ADD_INT(hash_packet, key, pkt);
		printf ("insert item. key=%d,value=%p \n", i, pkt);
	}
	printf ("hash count = %d \n", HASH_COUNT(hash_packet));

	/*通过key查找*/
	for (i=0; i<13; i++)
	{
		HASH_FIND_INT(hash_packet, &i, tmp);
		if (tmp == NULL)
		{
			printf ("find not item. key=%d,value=%p \n", i, tmp);
			continue;
		}
		printf ("find item. key=%d,value=%p \n", i, tmp);
	}

	printf ("hash count = %d \n", HASH_COUNT(hash_packet));

	/*遍历这个hash表*/
	struct packet* mytemp = NULL;
	for (mytemp = hash_packet; mytemp != NULL; mytemp = (packet*)mytemp->hh.next)
		printf (" %d => %s \n", mytemp->key, mytemp->msg);
	/*删除节点*/
	for (i=0; i<13; i++)
	{
		HASH_FIND_INT(hash_packet, &i, tmp);
		if (tmp == NULL)
		{
			printf ("find not item. key=%d,value=%p \n", i, tmp);
			continue;
		}
		/*删除节点不会释放你的空间必须自己释放*/
		HASH_DEL(hash_packet, tmp);
		free(tmp);
		printf ("delete itme. key=%d,value=%p \n", i, tmp);
	}
	printf ("hash count = %d \n", HASH_COUNT(hash_packet));

	system("pause");
	return 0;
}