io.go

// Part of Neubot <https://neubot.nexacenter.org/>.
// Neubot is free software. See AUTHORS and LICENSE for more
// information on the copying conditions.

package bernini

// Make sure I/O operations have a deadline
// See <https://groups.google.com/forum/#!topic/golang-nuts/afgEYsoV8j0>

import (
	"bufio"
	"errors"
	"io"
	"net"
	"time"
)

const IoTimeout = 10.0 * time.Second

func IoReadFull(conn net.Conn, reader io.Reader, data []byte) (int, error) {
	count := 0
	err := conn.SetReadDeadline(time.Now().Add(IoTimeout))
	if err != nil {
		return count, err
	}
	count, err = io.ReadFull(reader, data)
	if err != nil {
		return count, err
	}
	err = conn.SetReadDeadline(time.Time{})
	return count, err
}

func IoWriteByte(conn net.Conn, writer *bufio.Writer, data byte) error {
	err := conn.SetWriteDeadline(time.Now().Add(IoTimeout))
	if err != nil {
		return err
	}
	err = writer.WriteByte(data)
	if err != nil {
		return err
	}
	return conn.SetWriteDeadline(time.Time{})
}

func IoWrite(conn net.Conn, writer io.Writer, data []byte) (int, error) {
	count := 0
	err := conn.SetWriteDeadline(time.Now().Add(IoTimeout))
	if err != nil {
		return count, err
	}
	count, err = writer.Write(data)
	if err != nil {
		return count, err
	}
	err = conn.SetWriteDeadline(time.Time{})
	return count, err
}

func IoFlush(conn net.Conn, writer *bufio.Writer) error {
	err := conn.SetWriteDeadline(time.Now().Add(IoTimeout))
	if err != nil {
		return err
	}
	err = writer.Flush()
	if err != nil {
		return err
	}
	return conn.SetWriteDeadline(time.Time{})
}

func IoWriteString(conn net.Conn, writer *bufio.Writer, data string) (
	int, error) {
	count := 0
	err := conn.SetWriteDeadline(time.Now().Add(IoTimeout))
	if err != nil {
		return count, err
	}
	count, err = writer.WriteString(data)
	if err != nil {
		return count, err
	}
	err = conn.SetWriteDeadline(time.Time{})
	return count, err
}

func IoAccept(listener net.Listener) (net.Conn, error) {
	tcp_listener, okay := listener.(*net.TCPListener)
	if !okay {
		return nil, errors.New("Not a net.TCPListener")
	}
	err := tcp_listener.SetDeadline(time.Now().Add(IoTimeout))
	if err != nil {
		return nil, err
	}
	conn, err := tcp_listener.Accept()
	if err != nil {
		return nil, err
	}
	err = tcp_listener.SetDeadline(time.Time{})
	return conn, err
}