/* compare a key against an existing item's key  */
static int lv_lru_cmp_keys(lv_lru_item_t *item, const void *key, uint32_t key_length)
/* compare a key against an existing item's key  */
static int lv_lru_cmp_keys(lv_lru_item_t *item, const void *key, uint32_t key_length)
{
    if(key_length != item->key_length)
        return 1;
    else
        return memcmp(key, item->key, key_length);
}