various.go

package gomavlib

import (
	"fmt"
	"math/rand"
	"net"
	"time"
)

var errorTerminated = fmt.Errorf("terminated")

// netTimedConn forces a net.Conn to use timeouts
type netTimedConn struct {
	conn net.Conn
}

func (c *netTimedConn) Close() error {
	return c.conn.Close()
}

func (c *netTimedConn) Read(buf []byte) (int, error) {
	err := c.conn.SetReadDeadline(time.Now().Add(_NET_READ_TIMEOUT))
	if err != nil {
		return 0, err
	}
	return c.conn.Read(buf)
}

func (c *netTimedConn) Write(buf []byte) (int, error) {
	err := c.conn.SetWriteDeadline(time.Now().Add(_NET_WRITE_TIMEOUT))
	if err != nil {
		return 0, err
	}
	return c.conn.Write(buf)
}

func randomByte() byte {
	var buf [1]byte
	rand.Read(buf[:])
	return buf[0]
}

func uint24Decode(in []byte) uint32 {
	return uint32(in[2])<<16 | uint32(in[1])<<8 | uint32(in[0])
}

func uint24Encode(buf []byte, in uint32) []byte {
	buf[0] = byte(in)
	buf[1] = byte(in >> 8)
	buf[2] = byte(in >> 16)
	return buf[:3]
}

func uint48Decode(in []byte) uint64 {
	return uint64(in[5])<<40 | uint64(in[4])<<32 | uint64(in[3])<<24 |
		uint64(in[2])<<16 | uint64(in[1])<<8 | uint64(in[0])
}

func uint48Encode(buf []byte, in uint64) []byte {
	buf[0] = byte(in)
	buf[1] = byte(in >> 8)
	buf[2] = byte(in >> 16)
	buf[3] = byte(in >> 24)
	buf[4] = byte(in >> 32)
	buf[5] = byte(in >> 40)
	return buf[:6]
}