聊聊dubbo-go的TpsLimitFilter

const (
    // TpsLimitFilterKey key
    TpsLimitFilterKey = "tps"
)

func init() {
    extension.SetFilter(TpsLimitFilterKey, GetTpsLimitFilter)
}

type TpsLimitFilter struct {
}

// GetTpsLimitFilter ...
func GetTpsLimitFilter() filter.Filter {
    return &TpsLimitFilter{}
}

// Invoke ...
func (t TpsLimitFilter) Invoke(ctx context.Context, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result {
    url := invoker.GetUrl()
    tpsLimiter := url.GetParam(constant.TPS_LIMITER_KEY, "")
    rejectedExeHandler := url.GetParam(constant.TPS_REJECTED_EXECUTION_HANDLER_KEY, constant.DEFAULT_KEY)
    if len(tpsLimiter) > 0 {
        allow := extension.GetTpsLimiter(tpsLimiter).IsAllowable(invoker.GetUrl(), invocation)
        if allow {
            return invoker.Invoke(ctx, invocation)
        }
        logger.Errorf("The invocation was rejected due to over the tps limitation, url: %s ", url.String())
        return extension.GetRejectedExecutionHandler(rejectedExeHandler).RejectedExecution(url, invocation)
    }
    return invoker.Invoke(ctx, invocation)
}

// OnResponse ...
func (t TpsLimitFilter) OnResponse(_ context.Context, result protocol.Result, _ protocol.Invoker,
    _ protocol.Invocation) protocol.Result {
    return result
}