Example

if(!dr_cache_init(&hdl, (RefreshFunc_t)FnRefresh,
(FreeFunc_t)FnFree, (CompareFunc_t)FnCompare, 150000, 
PR_SecondsToInterval(7200)))
{
    ereport(LOG_FAILURE, "dr_cache_init() failed");
    return(REQ_ABORTED);
}