How do i check if channel is empty for a specific time while waiting for a message

[pavan.vitla (pavan kumar)]

Hi,

I am writing a go code with two functions readAndSendToCollector and collectAndPushToStream.

func readAndSendToCollector(w http.ResponseWriter, req *http.Request) {
    b, _ := ioutil.ReadAll(req.Body)
    bytesReader := bytes.NewReader(b)
    bufReader := bufio.NewReader(bytesReader)
    value, _, _ := bufReader.ReadLine()
    if len(value) != 0 {
        if debug || fine {
            fmt.Printf("%s\n", time.Now().Format("2006-01-02 15:04:05")+" Reading the request payload")
        }
        mEntry := new(streaming.Entry)
        mEntry.Key = []byte("dkey")
        mEntry.Value = value
        chanMessage <- *mEntry
    } 

func collectAndPushToStream(chanMessage chan streaming.Entry) {
    wg.Add(1)
    defer wg.Done()
    var pmdEntry []streaming.PutMessagesDetailsEntry = make([]streaming.Entry, 0, 100)
    var MAX_PAYLOAD_SIZE = 1000000  //1mb
    var totalPayloadSize = 0
    var completeBytesTransferred = 0
    for mEntry := range chanMessage {
        //fmt.Printf("key = %s   Value = %s\n", mEntry.Key, mEntry.Value)
        entryPayloadSize := len(mEntry.Key) + len(mEntry.Value)
        if (totalPayloadSize + entryPayloadSize) > MAX_PAYLOAD_SIZE {
            pushMessagesToStream(pmdEntry)
            completeBytesTransferred = completeBytesTransferred + totalPayloadSize
            fmt.Println("totalPayloadSize = " + strconv.Itoa(totalPayloadSize))
            fmt.Println("totalMessages = " + strconv.Itoa(len(pmdEntry)))
            fmt.Println("completeBytesTransferred = " + strconv.Itoa(completeBytesTransferred))
            totalPayloadSize = 0 //reset the payload size
            pmdEntry = pmdEntry[:0]
        }
        pmdEntry = append(pmdEntry, mEntry)
        totalPayloadSize = totalPayloadSize + entryPayloadSize
    }
} 

Here func readAndSendToCollector reads the payload from the http requests and pushes it to the channel chanMessage
And collectAndPushToStream reads the channel chanMessage and collects 1MB of data and pushes it to the Stream.

Sometimes there may less than 1MB of data available and I want to wait for 10 seconds and if there are no more data in the channel, I want to push the data available to the stream.
How do i wait for 10 seconds and check if there are any data in the channel?

[kron4eg (Artiom Di)]

With select with two cases, one for your channel and one with time.After()

select {
case <-time.After(10*time.Second):
    return timeoutErr
case var1 := <-yourChannel:
    return handleVar(var1)
}