golang实现简单区块链demo

package main

import (
    "bytes"
    "crypto/sha256"
    "encoding/binary"
    "fmt"
    "os"
    "time"
)

// 实现int转换成byte数组
func Int2Byte(num int64) []byte {
    var buffer bytes.Buffer
    err := binary.Write(&buffer, binary.BigEndian, num)
    CheckErr(err)
    return buffer.Bytes()
}

func CheckErr(err error) {
    if err != nil {
        fmt.Println("err:", err)
        os.Exit(1)
    }
}

//区块的结构
type Block struct {
    Version       int64
    PrevBlockHash []byte
    Hash          []byte
    TimeStamp     int64
    TargetBits    int64
    Nonce         int64
    MerkeRoot     []byte
    Data          []byte
}

func NewBlock(data string, prevBlockHash []byte) *Block {
    block := &Block{
        Version:       1,
        PrevBlockHash: prevBlockHash,
        TimeStamp:     time.Now().Unix(),
        TargetBits:    10,
        Nonce:         5,
        MerkeRoot:     []byte{},
        Data:          []byte(data)}
    block.SetHash()

    return block

}

// int -> byte

func (block *Block) SetHash() {
    tmp := [][]byte{
        //实现将int转成byte数组的函数
        Int2Byte(block.Version),
        block.PrevBlockHash,
        Int2Byte(block.TimeStamp),
        block.MerkeRoot,
        Int2Byte(block.Nonce),
        block.Data}
    //将区块个字段连接成一个切片，使用[]byte{}进行连接

    data := bytes.Join(tmp, []byte{})

    //算出hash的值
    hash := sha256.Sum256(data)
    block.Hash = hash[:]
}

func NewGenesisBlock() *Block {
    return NewBlock("Genesis Block!", []byte{})
}

type BlockChian struct {
    //使用切片保存区块，用于模拟区块链
    blocks []*Block
}

func NewBlockChain() *BlockChian {
    //创建一个区块链
    return &BlockChian{[]*Block{NewGenesisBlock()}}
}

func (bc *BlockChian) AddBlock(data string) {
    // 防止区块越界
    if len(bc.blocks) <= 0 {
        os.Exit(1)
    }
    lastBlock := bc.blocks[len(bc.blocks)-1]
    block := NewBlock(data, lastBlock.Hash)
    bc.blocks = append(bc.blocks, block)
}

func main() {
    // 实例化一个区块链
    bc := NewBlockChain()

    //添加block
    bc.AddBlock("测试第一个BTC")
    bc.AddBlock("测试第二个EOS")

    //打印出信息
    for i, block := range bc.blocks {
        fmt.Println("=========block num:", i)
        fmt.Println("data", string(block.Data))
        fmt.Println("Version:", block.Version)
        fmt.Printf("Hash:%x\n", block.Hash)
        fmt.Printf("TimeStamp:%d\n", block.TimeStamp)
        fmt.Printf("MerkeRoot:%x\n", block.MerkeRoot)
        fmt.Printf("None:%d\n", block.Nonce)
    }
}