在使用套接字时重用读取缓冲区

Question

I'd like to know the proper way to reuse the []byte buffer in go. I declare it like this

buf := make([]byte, 1024)

and then use like this

conn, _ := net.Dial("tcp", addr)
_, err = conn.read(buf)

I heard that declaring a new buffer isn't efficient since it involves memory allocations and that we should reuse existing buffers instead. However I am not sure if I just can pass the buffer again and it will be wiped or it can hold parts of previous messages (especially if the current message from socket is shorter than prev.one)?

Answer 1

In practice you rarely use io.Reader.Read(), instead you pipe it down where io.Reader needed in code. Buffer will not be wiped, you must do it by hand. Or if you want a buffer you can use bufio

conn, _ := net.Dial("tcp", addr)
r:=bufio.NewReader(conn)

which you can

r.WriteTo(io.Writer) //for example for further processing

and you can reset

r.Reset(NewConn)