#include <stdlib.h>
#include <stdio.h>
#include "uthash.h"

typedef struct hs_t {
    int id;
    int tag;
    UT_hash_handle hh;
} hs_t;


static void pr(hs_t **hdpp)
{
    hs_t *el, *tmp, *hdp = *hdpp;
    HASH_ITER(hh, hdp, el, tmp) {
        printf("id %d, tag %d\n",el->id,el->tag);
    }
}

int main()
{

    hs_t *hs_head=NULL, *tmp, *replaced=NULL;

    tmp = (hs_t*)malloc(sizeof(hs_t));
    if (tmp == NULL) {
        exit(-1);
    }
    tmp->id = 10;
    tmp->tag = 100;
    HASH_REPLACE_INT(hs_head,id,tmp,replaced);
    if(replaced == NULL) {
        printf("added %d %d\n",tmp->id,tmp->tag);
    } else {
        printf("ERROR, ended up replacing a value, replaced: %p\n",(void*)replaced);
    }

    pr(&hs_head);

    tmp = (hs_t*)malloc(sizeof(hs_t));
    if (tmp == NULL) {
        exit(-1);
    }
    tmp->id=11;
    tmp->tag = 101;
    HASH_REPLACE_INT(hs_head,id,tmp,replaced);
    if(replaced == NULL) {
        printf("added %d %d\n",tmp->id,tmp->tag);
    } else {
        printf("ERROR, ended up replacing a value, replaced: %p\n",(void*)replaced);
    }

    pr(&hs_head);

    tmp = (hs_t*)malloc(sizeof(hs_t));
    if (tmp == NULL) {
        exit(-1);
    }
    tmp->id=11;
    tmp->tag = 102;
    HASH_REPLACE_INT(hs_head,id,tmp,replaced);
    if(replaced == NULL) {
        printf("ERROR, exected to replace a value with key: %d\n",tmp->id);
    } else {
        printf("replaced %d that had tag %d with tag %d\n",tmp->id,replaced->tag,tmp->tag);
    }

    pr(&hs_head);

    return 0;
}