1package moxio

2

3import (

4 "io"

5 "net"

6)

7

8// PrefixConn is a net.Conn prefixed with a reader that is first drained.

9// Used for STARTTLS where already did a buffered read of initial TLS data.

10type PrefixConn struct {

11 PrefixReader io.Reader // If not nil, reads are fulfilled from here. It is cleared when a read returns io.EOF.

12 net.Conn

13}

14

15// Read returns data when PrefixReader when not nil, and net.Conn otherwise.

16func (c *PrefixConn) Read(buf []byte) (int, error) {

17 if c.PrefixReader != nil {

18 n, err := c.PrefixReader.Read(buf)

19 if err == io.EOF {

20 c.PrefixReader = nil

21 }

22 return n, err

23 }

24 return c.Conn.Read(buf)

25}

26