区块链 原理实现 Go

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前言：

 简单原理代码描述

core: 块、 区块实现 main: example 运行

BlockMain 执行目录：

package main

import "Chains/core"

func main() {
	sc := core.NewBlockChain()
	sc.SendData("send 1 btc to jacky")
	sc.SendData("send 1 eos to jack")
	sc.Print()
}

Block 区块：

package core

import (
	"crypto/sha256"
	"encoding/hex"
	"time"
)

type Block struct {
	Index int64 //区块编号
	Timestamp int64 //区块时间戳
	PreBlockHash string //上一个区哈希值
	Hash string //当前区块哈希值

	Data string //区块数据
}

func calculateHash(b Block) string{
	blockData :=  string(b.Index) + string(b.Timestamp) + b.PreBlockHash
	hashInBytes := sha256.Sum256([]byte(blockData))

	return hex.EncodeToString(hashInBytes[:])
}

func GenerateNewBlock(preBlock Block,data string) Block{
	newBlock := Block{}
	newBlock.Index = preBlock.Index + 1
	newBlock.PreBlockHash = preBlock.Hash
	newBlock.Timestamp = time.Now().Unix()
	newBlock.Hash = calculateHash(newBlock)

	return newBlock
}

func GenerateGenesisBlock() Block  {
	preBlock := Block{}
	preBlock.Index = 1
	preBlock.Hash = ""

	return GenerateNewBlock(preBlock,"Genesies Block")
}

BlockChain 区块链如何实现

package core

import (
	"log"
	"fmt"
)

type BlockChain struct {
	Blocks []*Block
}

func NewBlockChain() *BlockChain {
	genesisBlock := GenerateGenesisBlock()
	blockchain := BlockChain{}
	blockchain.ApendBlock(&genesisBlock)
	return &blockchain
}

func (bc *BlockChain) SendData(data string){

	preBlock := bc.Blocks[len(bc.Blocks)-1 ]
	newBlock := GenerateNewBlock(*preBlock,data)
	bc.ApendBlock(&newBlock)
}

func (bc *BlockChain)  ApendBlock(newBlock *Block){
	if len(bc.Blocks) == 0{
		bc.Blocks = append(bc.Blocks,newBlock)
		return
	}
	if  isValid(*newBlock,*bc.Blocks[len(bc.Blocks)-1]){
			bc.Blocks =  append(bc.Blocks,newBlock)
		}else{
			log.Fatal("invalid block")
	}
}

func (bc *BlockChain) Print(){
	for _,block := range bc.Blocks{
		fmt.Printf("Index:%d\n",block.Index)
		fmt.Printf("Pre.Hash:%s\n",block.PreBlockHash)
		fmt.Printf("Curr.Hash:%s\n",block.Hash)
		fmt.Printf("Data:%s\n",block.Data)
		fmt.Printf("TimeStamp:%d\n",block.Timestamp)
	}
}

func isValid(newBlock Block,oldBlack Block) bool{

	if newBlock.Index - 1 != oldBlack.Index {
		return false
	}
	if newBlock.PreBlockHash != oldBlack.Hash{
		return false
	}
	if calculateHash(newBlock) != newBlock.Hash{
		return false
	}
	return true
}

后续补充优化~~

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