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Question

我有 2 个缓冲 channel 为入站请求提供服务:

rabbitQ = make(chan map[string]interface{}, 1000)
sqsQ = make (chan map[string]interface{}, 1000)

我的调度程序函数如下所示:

func dispatchMessage(params map[string]interface{}) {

    if !shouldFailoverToSQS {
        select {
        case rabbitQ <- params:
            sentToRabbitMQ++
        case sqsQ <- params:
            sentToSQS++
        default:
            log.Error("Failed to dispatch mesaage to either RabbitMQ or SQS")
        }
    } else {
        sqsQ <- params
    }

}

我希望消息总是会发送到 rabbitQ，除非缓冲区已满，但我发现调用失败并在大约一半的时间内将消息发送到 sqsQ。这不是我想要的 - 我只想在 rabbitQ 已满时发送到 sqsQ。

我该如何强制执行？

Answer 1

根据 Voker 的评论，这就是我想出的:

func dispatchMessage(params map[string]interface{}) {

    //log.Debugf("Failover: %t, Len: %d", shouldFailoverToSQS, len(rabbitQ))

    if !shouldFailoverToSQS {
        select {
        case rabbitQ <- params:
            sentToRabbitMQ++
        default:
            select {
            case sqsQ <- params:
                sentToSQS++
            default:
                log.Error("Failed to dispatch mesaage to either RabbitMQ or SQS")
            }
        }
    } else {
        select {
        case sqsQ <- params:
            sentToSQS++
        default:
            log.Error("Failed to dispatch mesaage to either RabbitMQ or SQS")
        }
    }

}