bitio

bitio is Golang library for bit reader/writer.

Support Type

• bool
• int (int8 - int64)
• uint (uint8 - uint64)
• string (fixed size)
• array (fixed length)
• slice (variable length)

Syntax

Type	Syntax	Description
field size (bit)	bit:"1"	value size is 1 bit.
field size (byte)	byte:"2"	value size is 2 bytes.
array length	len:"3"	array is composed of 3 values.
slice length	len:"Len"	slice is composed of Len values.
endianness	endian:"big"	value is big-endian. (default: little-endian)

Example

BitField Reader/Writer

type Container struct {
	Sign []byte `bit:"4" len:"3"`       // 4bit x 3
	Size int    `bit:"4"`               // 4bit
	Name string `byte:"8"`              // 8byte (8chars)
	Data []byte `byte:"1" len:"Size"`   // 1byte x Size
	CRC  uint   `bit:"32" endian:"big"` // 32bit (4byte), big endian
}

func ReadContainer(r io.Reader) (*Container, error) {
	c := &Container{}

	br := bitio.NewBitFieldReader(r)
	if _, err := br.ReadStruct(c); err != nil {
		return nil, err
	}

	return c, nil
}

func WriteContainer(w io.Writer, c *Container) (nBit int, err error) {
	bw := bitio.NewBitFieldWriter(w)
	if nBit, err = bw.WriteStruct(c); err != nil {
		return
	}

	return
}

Bit Reader/Writer

func ReadBit(r io.Reader) (byte, []byte, []byte) {
	br := bitio.NewBitReadBuffer(r)

	//read 4bit
	var b1 byte
	br.ReadBit(&b1, 4)

	//read 12bit
	b2 := make([]byte, 2)
	br.ReadBits(b2, 12)

	//read 2byte(16bit)
	b3 := make([]byte, 2)
	br.Read(b3)

	return b1, b2, b3
}

func WriteBit(w io.Writer) {
	bw := bitio.NewBitWriteBuffer(w)

	//write 4bit
	bw.WriteBit(0x01, 4)

	//write 12bit
	b2 := []byte{0x02, 0x34}
	bw.WriteBits(b2, 12)

	//write 2byte(16bit)
	b3 := []byte{0x56, 0x78}
	bw.Write(b3)

	bw.Flush()
}