288-BitCoin全攻略四_添加区块

BitCoin全攻略四







我们创建完了区块链
现在我们来写一个方法
往区块链里面添加区块

func (bc *BlockChain) AddBlock(data []byte){

	//获取前一个区块
	lastBlock := bc.Blocks[len(bc.Blocks) - 1]
	
	//获取前一个区块的hash值
	prevHash := lastBlock.Hash

	//创建当前区块
	newBlock := NewBlock(data, prevHash)

	//添加到区块链
	bc.Blocks = append(bc.Blocks, newBlock)

}







然后我们看一下完整代码

package main

import (
	"crypto/sha256"
	"fmt"
)

type Block struct {
	//1.前区块哈希值
	PrevBlockHash []byte

	//2.当前区块的哈希
	Hash []byte

	//3.数据
	Data []byte
}

type BlockChain struct {
	Blocks []*Block
}

func main() {

	blockchain := NewBlockChain()
	blockchain.AddBlock([]byte("I am Alice"))
	blockchain.AddBlock([]byte("I am Bob"))
	blockchain.AddBlock([]byte("I am Mike"))
	blockchain.AddBlock([]byte("I am Andy"))

	blocks := blockchain.Blocks

	for i, block := range blocks {
		fmt.Println("========== 当前区块 ", i, "==========")
		fmt.Printf("前一区块的hash值为: %x\n", block.PrevBlockHash)
		fmt.Printf("当前区块的hash值为: %x\n", block.Hash)
		fmt.Printf("当前区块的data为: %s\n", block.Data)
	}

}

func (bc *BlockChain) AddBlock(data []byte) {

	//获取前一个区块
	lastBlock := bc.Blocks[len(bc.Blocks)-1]

	//获取前一个区块的hash值
	prevHash := lastBlock.Hash

	//创建当前区块
	newBlock := NewBlock(data, prevHash)

	//添加到区块链
	bc.Blocks = append(bc.Blocks, newBlock)

}

func NewBlockChain() *BlockChain {

	genesisInfo := []byte("Hello world! Hello blockchain!")
	genesisBlock := NewBlock(genesisInfo, []byte{})

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

	return &bc
}

func NewBlock(data []byte, prevBlockHash []byte) *Block {

	block := Block{
		PrevBlockHash: prevBlockHash,
		Hash:          nil,
		Data:          data,
	}

	hash := getHash(&block)
	block.Hash = hash

	return &block
}

func getHash(block *Block) []byte {
	var info []byte
	info = append(info, block.PrevBlockHash...)
	info = append(info, block.Data...)
	hash := sha256.Sum256(info)
	return hash[:]
}





然后我们看下输出结果

========== 当前区块  0 ==========
前一区块的hash值为: 
当前区块的hash值为: 93a26c42840ed836279f3b703386d14649c0052feb3ba5ac1796061f81898aec
当前区块的data为: Hello world! Hello blockchain!
========== 当前区块  1 ==========
前一区块的hash值为: 93a26c42840ed836279f3b703386d14649c0052feb3ba5ac1796061f81898aec
当前区块的hash值为: af3ddf737847a34a42faadf2f39546e1a6966cc856610f13d57ab32954b797c2
当前区块的data为: I am Alice
========== 当前区块  2 ==========
前一区块的hash值为: af3ddf737847a34a42faadf2f39546e1a6966cc856610f13d57ab32954b797c2
当前区块的hash值为: 4aadccb1b8527dbd4dab81039fb243a9421e2346df6df975ffab98da501cc03d
当前区块的data为: I am Bob
========== 当前区块  3 ==========
前一区块的hash值为: 4aadccb1b8527dbd4dab81039fb243a9421e2346df6df975ffab98da501cc03d
当前区块的hash值为: 13fb213a47048fa2f643b22e55f85f6dc97fb99dabd8fbaabe46fad13357c09c
当前区块的data为: I am Mike
========== 当前区块  4 ==========
前一区块的hash值为: 13fb213a47048fa2f643b22e55f85f6dc97fb99dabd8fbaabe46fad13357c09c
当前区块的hash值为: c5fed60d59e5fa4c5a867c8516adf6ce5c23dbef5176d10f0ca87f07db14fd9b
当前区块的data为: I am Andy


我们发现hash值的指向都没问题