区块链V1版本实现之五

代码重构：

block.go文件：

package main

import (
   "crypto/sha256"
)

//定义区块结构
type Block struct {
   //前区块哈希
   PrevBlockHash [] byte
   //当前区块哈希
   Hash [] byte
   //数据，目前使用字节流，v4开始使用交易代替
   Data [] byte
}

const genesisInfo = "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks"

//创建区块，对Block的每一个字段填充数据
func NewBlock(data string, prevBlockHash []byte) *Block{
   block := Block{
      PrevBlockHash: prevBlockHash,
      Hash:          []byte{}, //先填充为空
      Data:          []byte(data),
   }

   //V1之二版本添加实现hash输出
   block.SetHash()

   return &block
}

//为了生成区块哈希，实现一个简单的函数，来计算哈希值，没有随机值，没有难度值
func (block *Block) SetHash() {
   var data []byte
   data = append(data, block.PrevBlockHash...)
   data = append(data, block.Data...)

   hash /* [32]byte */:= sha256.Sum256(data)
   block.Hash = hash[:]
}

blockchain.go文件：

package main

//创建区块链，使用Block数组模拟
type BlockChain struct {
   Blocks []*Block
}

//实现创建区块链的方法
func NewBlockChain() *BlockChain {
   //在创建的时候添加一个区块：创世块
   genesisBlock := NewBlock(genesisInfo, []byte{0x0000000000000000})

   bc := BlockChain{Blocks: []*Block{genesisBlock}}
   return &bc
}

//添加区块
func (bc *BlockChain) AddBlock(data string) {

   //创建一个区块
   //bc.Block的最后一个区块的Hash值就是当前新区块的PrevBlockHash
   lastBlock := bc.Blocks[len(bc.Blocks) - 1]
   prevHash := lastBlock.Hash

   block := NewBlock(data, prevHash)

   //添加到bc.Block数组中
   bc.Blocks = append(bc.Blocks, block)

}

main.go文件：

package main

import (
   "fmt"
)

func main()  {
   fmt.Printf("HelloWorld!!!\n")

   ////区块实例化
   //block := NewBlock(genesisInfo,[]byte{0x0000000000000000})
   bc := NewBlockChain()
   bc.AddBlock("哈哈哈哈哈")

   for i, block := range bc.Blocks{
      //区块打印
      fmt.Printf("++++++++++++++ %d ++++++++++++++++\n",i)
      fmt.Printf("PrevBlockHash : %x\n", block.PrevBlockHash)
      fmt.Printf("Hash : %x\n", block.Hash)
      fmt.Printf("Data : %s\n", block.Data)
   }
}

显示效果：