protocol

Documentation

Overview

Protocol package implements a simple protocol for sending and receiving data.

Protocol format: ABBCCCCDDD...DDDFFFF Where: A: command byte B: counter (2 bytes, big endian) optional used to debug and validate package order C: payload length (32 bits, big endian) D: payload (array of bytes) F: checksum (FNV-1a, 32 bits, big endian)

The checksum is calculated over the command byte, counter, payload length, and the data itself.

Index

• Constants
• Variables
• func Decode(dest, src []byte) (cmd byte, n int, counter uint16, err error)
• func Encode(dest, src []byte, cmd byte, counter uint16) (int, error)

Examples

• Decode
• Encode

Constants

const (
	MaxPackageSize = constants.BufferSize + 11 // max package size
)

Variables

var (
	ErrInvalidSize     = errors.New("invalid size")
	ErrInvalidChecksum = errors.New("invalid checksum")
)

Functions

func Decode

func Decode(dest, src []byte) (cmd byte, n int, counter uint16, err error)

Decode decodes the source buffer into the destination buffer. It returns the command byte, the number of bytes read, the counter value, and an error, if any. command byte + counter + data length + checksum length = 11 bytes

Example

Output:

cmd: 01
data: hello

func Encode

func Encode(dest, src []byte, cmd byte, counter uint16) (int, error)

Encode encodes the source data into the destination buffer using the specified command. It returns the number of bytes written and an error, if any.

Example

Output:

data: 0100010000000568656C6C6F7CE86368