1. What's the web server you're connecting to? (Is it written in go, and if so, can you share it?) 2. What happens if you use io.Read instead of io.ReadAtLeast? 3. What happens if you remove the time.Sleep()? (Maybe the target webserver has a timeout which requires the transaction to be completed within 30 seconds?)
*io.ReadAtLeast* does exactly what it says: read *at least* that number of bytes. If the sender has nothing more to send, and does not end the stream, then it will wait indefinitely for more data. Note that io.ReadAtLeast never returns io.EOF, but it may return io.ErrUnexpectedEOF if it's unable to read the number of requested bytes. For source code see here <https://cs.opensource.google/go/go/+/refs/tags/go1.18.3:src/io/io.go;l=325> . However, even if the sender does drop the connection, it does seem weird that you don't get an error. (I don't suppose you are going through a badly-configured firewall with an aggressive TCP timeout and which doesn't send RST?) On Monday, 20 June 2022 at 06:44:38 UTC+1 minxie...@gmail.com wrote: > All, > > I got puzzled by how to read a response size > 32KBytes from http > resp.Body. All I get is 32768 bytes. With either io.Read functions or > bufio.Reader. > > > > > > > > > > > > > > > > > > > *buffer := make([]byte, 1024)var total_bytes_read int for { len, err := > io.ReadAtLeast(res.Body, buffer, 1024) total_bytes_read += len > log.Println(len, "bytes recevied, total received bytes: ", > total_bytes_read) if err != nil { if err == io.EOF { > log.Println("EOF: last chunk received") } else { log.Println(err) > } break } time.Sleep(1 * time.Second)} log.Println("Total bytes > received:", total_bytes_read)err = res.Body.Close()* > > What I see is: > > *{"level":"info","msg":"1024 bytes recevied, total received bytes: > 1024","time":"2022-06-19T19:47:48-05:00"} * > *{"level":"info","msg":"1024 bytes recevied, total received bytes: > 2048","time":"2022-06-19T19:47:49-05:00"} * > > *{"level":"info","msg":"1024 bytes recevied, total received bytes: > 3072","time":"2022-06-19T19:47:50-05:00"}* > *...* > *{"level":"info","msg":"1024 bytes recevied, total received bytes: > 30720","time":"2022-06-19T19:48:17-05:00"}* > *{"level":"info","msg":"1024 bytes recevied, total received bytes: > 31744","time":"2022-06-19T19:48:18-05:00"} * > *{"level":"info","msg":"1024 bytes recevied, total received bytes: > 32768","time":"2022-06-19T19:48:19-05:00"}* > > Then it got stuck and waiting for return from the io.Read. Not sure if > what I did is correct. Got the same observation when using more popular > bufio.Read as well. > > Thanks! > -Min > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/ae86d64e-e824-4b7c-83ed-a106cd537f37n%40googlegroups.com.
