简单实现区块链

//Filename:BlockChain
//Date:2018-06-21 21:27
//auther:Mudy
//E-mail:2808050775@qq.com
//Blog:txmudy.cn
package main

import (
    "time"
    "crypto/sha256"
    "encoding/hex"
    "github.com/labstack/echo"
    "fmt"
)

type BlockModel struct {
    Id int64 // 索引
    TimeStamp string //区块创建的时间标识
    BPM int //每分钟心跳
    Hash string //区块哈希
    PreHash string//上一块的哈希 sha256
}

//区块链，数组
var BlockChain  = make([]BlockModel,0)

//创建第一个区块，创世区块
func init()  {
    //创建了一个区块
    block := BlockModel{0,time.Now().String(),0,"",""}
    BlockChain = append(BlockChain,block)//加入数组
}

// 哈希处理
func calHash(block BlockModel) string {
    record := string(block.Id) + block.TimeStamp + string(block.BPM) + block.PreHash
    myhash := sha256.New()
    myhash.Write([]byte(record))
    hashed := myhash.Sum(nil)
    return hex.EncodeToString(hashed)//编码为字符串
}

func is_BLockValid(newBlock,lastBlock BlockModel) bool {
    //id不能相等 必须是顺序的
    if lastBlock.Id + 1 != newBlock.Id {
        return false
    }

    //前一块的哈希，不等于新区快的哈希
    if lastBlock.Hash != newBlock.PreHash{
        return false
    }

    if calHash(newBlock) != newBlock.Hash {//数据被修改

    }
    return true
}

//处理区块的创建
func createBlock(ctx echo.Context)  error{
    //处理心跳信息
    type message struct {
        BPM int
    }

    var mymessage = message{}
    if err := ctx.Bind(&mymessage); err != nil{//绑定消息处理
        panic(err)//处理错误
    }
    lastblock := BlockChain[len(BlockChain)-1]//前一个区块
    //使用前一个区块，创建新的区块
    newBlock := BlockModel{}
    newBlock.Id = lastblock.Id + 1
    newBlock.TimeStamp = time.Now().String()
    newBlock.BPM = mymessage.BPM
    newBlock.PreHash = lastblock.Hash
    newBlock.Hash = calHash(newBlock)

    if is_BLockValid(newBlock,lastblock) {
        BlockChain = append(BlockChain,newBlock)
        fmt.Println("创建区块成功",BlockChain[len(BlockChain)-1].Id)
    }else {
        fmt.Println("创建区块失败")
    }

    return ctx.JSON(200,newBlock)
}

func main() {
    echoServer := echo.New()//创建服务器
    echoServer.GET("/", func(context echo.Context) error {
        return context.JSON(200,BlockChain)
    })

    echoServer.POST("/",createBlock)
    echoServer.Logger.Fatal(echoServer.Start(":8800"))
}

最终的实现效果如下:

Untitled.gif