目录：
一.初始化区块链
1.代码结构
2. 定义区块结构与方法
3. 定义区块链结构与方法
4. 帮助库代码
5. 测试生成区块与初始化区块链
6. 测试代码
二. POW挖矿实现
1.代码结构
2. 定义pow算法实现
3. 修改区块的生成方式(从自定义到挖矿)
4. 测试代码，测试挖矿
5.验证区块有效性
一.初始化区块链
1. 代码结构
Block.go :定义区块结构与方法
BlockChain.go :定义区块链结构与方法
help.go :将常用代码块进行封装，形成帮助库
main.go:测试代码
2.定义区块结构与方法
package BLCimport ( "time" "strconv" "bytes" "crypto/sha256")//定义区块type Block struct { //1.区块高度，也就是区块的编号，第几个区块 Height int64 //2.上一个区块的Hash值 PreBlockHash []byte //3.交易数据（最终都属于transaction 事务） Data []byte //4.创建时间的时间戳 TimeStamp int64 //5.当前区块的Hash值 Hash []byte //6.Nonce 随机数，用于验证工作量证明 Nonce int64}//定义区块生成Hash的方法func (block *Block) SetHash() { //1.将Height 转换为字节数组 []byte heightBytes := IntToHex(block.Height) //2.将TimeStamp 转换为字节数组 []byte //2.1 将Int64的TimeStamp 转换成二进制 timeString := strconv.FormatInt(block.TimeStamp, 2) //2.2 将二进制字符串转成字节数组 timeBytes := []byte(timeString) //3.拼接所有属性,形成一个二维的byte数组 blockBytes := bytes.Join([][]byte{heightBytes, block.PreBlockHash, block.Data, timeBytes, block.Hash}, []byte{}) //4.生成Hash hash := sha256.Sum256(blockBytes) block.Hash = hash[:]}//1. 创建新的区块func NewBlock(data string, height int64, PreBlockHash []byte) *Block { //创建区块 block := &Block{ height, PreBlockHash, []byte(data), time.Now().Unix(), nil, 0, } //设置Hash block.SetHash() return block}//2.生成创世区块func CreateGenesisBlock(data string) *Block { return NewBlock(data, 1, []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})}3.定义区块链与方法
package BLCtype BlockChain struct { Blocks []*Block //存储有序的区块}func (blc *BlockChain)AddBlockChain(data string,height int64,preHash []byte){ //创建新区块 newBlock := NewBlock(data,height,preHash) //往链中添加区块 blc.Blocks=append(blc.Blocks,newBlock)}//1.创建带有创世区块的区块链func CreateBlockChainWithGenesisBlock() *BlockChain { //创建创世区块 genesisBlock := CreateGenesisBlock("Genesis Data..") //返回区块链对象 return &BlockChain{[]*Block{genesisBlock}}}4.帮助代码库
package BLCimport ( "bytes" "encoding/binary" "log")//将int64转换为字节数组func IntToHex(num int64) []byte { buff := new(bytes.Buffer) err := binary.Write(buff, binary.BigEndian, num) if err != nil { log.Panic(err) } return buff.Bytes()}5.测试代码
package mainimport ( "publicChain/BLC" "fmt")func main() { //创建创世区块 blockChain := BLC.CreateBlockChainWithGenesisBlock() //创建新的区块 blockChain.AddBlockChain("Send $100 to Bruce", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) blockChain.AddBlockChain("Send $200 to Apple", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) blockChain.AddBlockChain("Send $300 to Alice", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) blockChain.AddBlockChain("Send $400 to Bob", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) fmt.Printf("创建的区块链为:\t%v\n", blockChain) fmt.Printf("区块链存储的区块为:\t%v\n", blockChain.Blocks) fmt.Printf("第二个区块的数据信息(交易信息)为:\t%v\n", string(blockChain.Blocks[1].Data))}结果显示
二. POW挖矿实现
1.代码结构
多出的ProofOfWork.go用于实现挖矿
2. 定义pow算法实现
ProofOfWork.go
package BLCimport ( "math/big" "bytes" "crypto/sha256" "fmt" "time")type ProofOfWork struct { Block *Block //当前要验证的区块 target *big.Int //大数存储，区块难度}//数据拼接，返回字节数组func (pow *ProofOfWork) prePareData(nonce int) []byte { data := bytes.Join( [][]byte{ pow.Block.PreBlockHash, pow.Block.Data, IntToHex(pow.Block.TimeStamp), IntToHex(int64(targetBit)), IntToHex(int64(nonce)), IntToHex(int64(pow.Block.Height)), }, []byte{}, ) return data}//256位Hash里面至少要有16个零0000 0000 0000 0000const targetBit = 16func (proofOfWork *ProofOfWork) Run(num int64) ([]byte, int64) { //3.判断Hash的有效性，如果满足条件循环体 nonce := 0 var hashInt big.Int //存储新生成的hash值 var hash [32]byte for { //1. 将Block的属性拼接成字节数组 databytes := proofOfWork.prePareData(nonce) //2.生成Hash hash = sha256.Sum256(databytes) fmt.Printf("挖矿中..%x\n", hash) //3. 将hash存储至hashInt hashInt.SetBytes(hash[:]) //4.判断hashInt是否小于Block里面的target // Cmp compares x and y and returns: // // -1 if x < y // 0 if x == y // +1 if x > y //需要hashInt(y)小于设置的target(x) if proofOfWork.target.Cmp(&hashInt) == 1 { //fmt.Println("挖矿成功", hashInt) fmt.Printf("第%d个区块，挖矿成功:%x\n",num,hash) fmt.Println(time.Now()) time.Sleep(time.Second * 2) break } nonce ++ } return hash[:], int64(nonce)}//创建新的工作量证明对象func NewProofOfWork(block *Block) *ProofOfWork { /*1.创建初始值为1的target 0000 0001 8 - 2 */ target := big.NewInt(1) //2.左移256-targetBit target = target.Lsh(target, 256-targetBit) return &ProofOfWork{block, target}}3. 修改区块的生成方式(从自定义到挖矿)
Block.go
package BLCimport ( "time")//定义区块type Block struct { //1.区块高度，也就是区块的编号，第几个区块 Height int64 //2.上一个区块的Hash值 PreBlockHash []byte //3.交易数据（最终都属于transaction 事务） Data []byte //4.创建时间的时间戳 TimeStamp int64 //5.当前区块的Hash值 Hash []byte //6.Nonce 随机数，用于验证工作量证明 Nonce int64}//1. 创建新的区块func NewBlock(data string, height int64, PreBlockHash []byte) *Block { //创建区块 block := &Block{ height, PreBlockHash, []byte(data), time.Now().Unix(), nil, 0, } //调用工作量证明的方法，并且返回有效的Hash和Nonce值 //创建pow对象 pow := NewProofOfWork(block) //挖矿验证 hash, nonce := pow.Run(height) block.Hash = hash[:] block.Nonce = nonce return block}//2.生成创世区块func CreateGenesisBlock(data string) *Block { return NewBlock(data, 1, []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})}4. 测试代码，测试挖矿
main.go
package mainimport ( "publicChain/part2-工作量证明/BLC" "fmt")func main() { fmt.Println("开始挖矿") //创建创世区块 blockChain := BLC.CreateBlockChainWithGenesisBlock() //创建新的区块 blockChain.AddBlockChain("Send $100 to Bruce", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) blockChain.AddBlockChain("Send $200 to Apple", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) blockChain.AddBlockChain("Send $300 to Alice", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) blockChain.AddBlockChain("Send $400 to Bob", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash) fmt.Printf("创建的区块链为:\t%v\n", blockChain) fmt.Printf("区块链存储的区块为:\t%v\n", blockChain.Blocks) fmt.Printf("第二个区块的数据信息(交易信息)为:\t%v\n", string(blockChain.Blocks[1].Data)) fmt.Printf("第二个区块的随机数为:\t%v\n", blockChain.Blocks[1].Nonce)}测试结果
共计对五个区块进行挖矿，结果如上
5.验证区块有效性
ProofOfWork.go
//判断挖矿得到的区块是否有效func (proofOfWork *ProofOfWork) IsValid() bool { //1.proofOfWork.Block.Hash //2.proofOfWork.Target var hashInt big.Int hashInt.SetBytes(proofOfWork.Block.Hash) if proofOfWork.target.Cmp(&hashInt) == 1 { return true } return false}测试代码:
main.go
//通过POW挖出新的区块blockblock := BLC.NewBlock("Send $500 to Tom", blockChain.Blocks[len(blockChain.Blocks)-1].Height+1, blockChain.Blocks[len(blockChain.Blocks)-1].Hash)//手动将该区块添加至区块链中blockChain.Blocks = append(blockChain.Blocks, block)//创建一个工作量证明对象proofOfWork := BLC.NewProofOfWork(block)//判断该区块是否合法有效fmt.Println(proofOfWork.IsValid())测试结果:
第六个区块是我们新创建的区块，返回值为true，验证有效
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