binary

Documentation

Index

• Constants
• Variables
• func New() varintStream
• func PutUvarint(buf []byte, x uint64) int
• func PutVarint(buf []byte, x int64) int
• func Read(r io.Reader, order ByteOrder, data any) error
• func ReadUvarint(r io.ByteReader) (uint64, error)
• func ReadVarint(r io.ByteReader) (int64, error)
• func Size(v any) int
• func Uvarint(buf []byte) (uint64, int)
• func Varint(buf []byte) (int64, int)
• func Write(w io.Writer, order ByteOrder, data any) error
• type ByteOrder

Examples

• ByteOrder (Get)
• ByteOrder (Put)
• PutUvarint
• PutVarint
• Read
• Read (Multi)
• Uvarint
• Varint
• Write
• Write (Multi)

Constants

const (
	MaxVarintLen16 = 3
	MaxVarintLen32 = 5
	MaxVarintLen64 = 10
)

Variables

var BigEndian bigEndian

var LittleEndian littleEndian

Functions

func New

func New() varintStream

func PutUvarint

func PutUvarint(buf []byte, x uint64) int

Example

package main

import (
	"encoding/binary"
	"fmt"
)

func main() {
	buf := make([]byte, binary.MaxVarintLen64)

	for _, x := range []uint64{1, 2, 127, 128, 255, 256} {
		n := binary.PutUvarint(buf, x)
		fmt.Printf("%x\n", buf[:n])
	}
}

func PutVarint

func PutVarint(buf []byte, x int64) int

Example

package main

import (
	"encoding/binary"
	"fmt"
)

func main() {
	buf := make([]byte, binary.MaxVarintLen64)

	for _, x := range []int64{-65, -64, -2, -1, 0, 1, 2, 63, 64} {
		n := binary.PutVarint(buf, x)
		fmt.Printf("%x\n", buf[:n])
	}
}

func Read

func Read(r io.Reader, order ByteOrder, data any) error

Example

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"

	"github.com/ddkwork/golibrary/mylog"
)

func main() {
	var pi float64
	b := []byte{0x18, 0x2d, 0x44, 0x54, 0xfb, 0x21, 0x09, 0x40}
	buf := bytes.NewReader(b)
	mylog.Check(binary.Read(buf, binary.LittleEndian, &pi))
	fmt.Print(pi)
}

Example (Multi)

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"

	"github.com/ddkwork/golibrary/mylog"
)

func main() {
	b := []byte{0x18, 0x2d, 0x44, 0x54, 0xfb, 0x21, 0x09, 0x40, 0xff, 0x01, 0x02, 0x03, 0xbe, 0xef}
	r := bytes.NewReader(b)

	var data struct {
		PI   float64
		Uate uint8
		Mine [3]byte
		Too  uint16
	}

	mylog.Check(binary.Read(r, binary.LittleEndian, &data))

	fmt.Println(data.PI)
	fmt.Println(data.Uate)
	fmt.Printf("% x\n", data.Mine)
	fmt.Println(data.Too)
}

func ReadUvarint

func ReadUvarint(r io.ByteReader) (uint64, error)

func ReadVarint

func ReadVarint(r io.ByteReader) (int64, error)

func Size

func Size(v any) int

func Uvarint

func Uvarint(buf []byte) (uint64, int)

Example

package main

import (
	"encoding/binary"
	"fmt"
)

func main() {
	inputs := [][]byte{
		{0x01},
		{0x02},
		{0x7f},
		{0x80, 0x01},
		{0xff, 0x01},
		{0x80, 0x02},
	}
	for _, b := range inputs {
		x, n := binary.Uvarint(b)
		if n != len(b) {
			fmt.Println("Uvarint did not consume all of in")
		}
		fmt.Println(x)
	}
}

func Varint

func Varint(buf []byte) (int64, int)

Example

package main

import (
	"encoding/binary"
	"fmt"
)

func main() {
	inputs := [][]byte{
		{0x81, 0x01},
		{0x7f},
		{0x03},
		{0x01},
		{0x00},
		{0x02},
		{0x04},
		{0x7e},
		{0x80, 0x01},
	}
	for _, b := range inputs {
		x, n := binary.Varint(b)
		if n != len(b) {
			fmt.Println("Varint did not consume all of in")
		}
		fmt.Println(x)
	}
}

func Write

func Write(w io.Writer, order ByteOrder, data any) error

Example

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"math"

	"github.com/ddkwork/golibrary/mylog"
)

func main() {
	buf := new(bytes.Buffer)
	pi := math.Pi
	mylog.Check(binary.Write(buf, binary.LittleEndian, pi))
	fmt.Printf("% x", buf.Bytes())
}

Example (Multi)

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"

	"github.com/ddkwork/golibrary/mylog"
)

func main() {
	buf := new(bytes.Buffer)
	data := []any{
		uint16(61374),
		int8(-54),
		uint8(254),
	}
	for _, v := range data {
		mylog.Check(binary.Write(buf, binary.LittleEndian, v))
	}
	fmt.Printf("%x", buf.Bytes())
}

Types

type ByteOrder

type ByteOrder interface {
	Uint16([]byte) uint16
	Uint32([]byte) uint32
	Uint64([]byte) uint64
	PutUint16(uint16) []byte
	PutUint32(uint32) []byte
	PutUint64(uint64) []byte
	String() string
}

Example (Get)

package main

import (
	"encoding/binary"
	"fmt"
)

func main() {
	b := []byte{0xe8, 0x03, 0xd0, 0x07}
	x1 := binary.LittleEndian.Uint16(b[0:])
	x2 := binary.LittleEndian.Uint16(b[2:])
	fmt.Printf("%#04x %#04x\n", x1, x2)
}

Example (Put)

package main

import (
	"encoding/binary"
	"fmt"
)

func main() {
	b := make([]byte, 4)
	binary.LittleEndian.PutUint16(b[0:], 0x03e8)
	binary.LittleEndian.PutUint16(b[2:], 0x07d0)
	fmt.Printf("% x\n", b)
}