genid

func (h *serviceHandler) GetId(ctx context.Context,
    req *id.Request, resp *id.Response) error {
    logs.Info("GetId with request: %#v", req)
    defer logs.Trace("GetId out: %#v", resp)
    t := time.Now().Local()
    dt := t.Format("060102") // format time yymmdd
    key := fmt.Sprintf("id:%d", req.Type)
    curr := h.redis.Incr(key)
    val, err := curr.Val(), curr.Err()
    if err != nil {
        if span := opentracing.SpanFromContext(ctx); span != nil {
            span.SetTag("error", req.Type)
            ext.Error.Set(span, true)
        }
        logs.Error("Error when INCR id, error: %#v", err)
        return err
    }
    resp.Auto = val
    if req.Type != id.TYPE_NONE {
        resp.Id = fmt.Sprintf("%sT%03d%08d", dt, req.Type, val)
    }
    if len(req.Prefix) > 0 {
        //* 181030T04100003934 -> M181030-04100003934
        //* 181030T04100003934 -> M181114-00000033
        resp.Idx = fmt.Sprintf("%s%s-%03d%08d", req.Prefix, dt, req.Type, val)
    }
    return nil
}