关于go:Go-区块链实现

mkdir BlockChain && cd BlockChain && go mod init BlockChain
mkdir block blockChain
touch main.go block/block.go blockChain/blockChain.go

func CalcHash(tobeHash string) string {
    // "crypto/sha256"
    // func Sum256(data []byte) [Size]byte
    // size = 32, 32 byte = 256 bit
    tobeHash_256 := sha256.Sum256([]byte(tobeHash))

    // "encoding/hex"
    // func EncodeToString(src []byte) string
    return hex.EncodeToString(tobeHash_256[:])
}

类定义

// block
type Block struct{
    Index         int64  // 区块编号
    Timestamp     int64  // 区块工夫戳
    PrevBlockHash string // 上一个区块的哈希值
    Data          string // 以后区块数据
    Hash          string // 以后区块哈希值
}

办法

计算以后区块哈希值

func CalcHash(b *Block) string {total_block_data := string(Index) + string(Timestamp) + b.PrevBlockHash + b.Data
    block_data_sha256 := sha256.Sum256([]byte(total_block_data))
    return hex.EncodeToString(block_data_sha256[:])
}

生成区块

func GenerateBlock(prevBlock *Block, data string) *Block{new_block := Block{}
    new_block.Index = prevBlock.Index + 1
    new_block.Timestamp = time.Now().Unix()
    new_block.PrevBlockHash = prevBlock.PrevBlockHash
    new_block.Data = data
    new_block.Hash = CalcHash(&new_block)
    
    return &new_block
}

创世块 (第一个 block)

func GenesisBlock() *Block{prevBlock := Block{}
    prevBlock.Index = -1
    prevBlock.PrevBlockHash = ""return GenerateBlock(&prevBlock,"Genesis Block")
}

测试

package main

import("fmt")

func main(){a := GenesisBlock()
    b := GenerateBlock(a, "first block")
    fmt.Println(a)
    fmt.Println(b)
}

$ go run main.go  
&{0 1666282848  Genesis Block 90d7d6d9adc8a6dd4eca1e30d8c1a8556a8e3e508da81f30a9e520c2ee7124b0}
&{1 1666282848 90d7d6d9adc8a6dd4eca1e30d8c1a8556a8e3e508da81f30a9e520c2ee7124b0 first block 16f4d5551953062eca3e7858c28726967d6129f03ac393175efb6044e797589b}

类定义

type BlockChain struct{Blocks []*block.Block
    Count int64
}

初始化区块链

func NewBlockChain() *BlockChain{bc := BlockChain{}
    bc.Blocks = append(bc.Blocks, block.GenesisBlock())
    bc.Count++
    return &bc
}

区块链间接减少区块

func (bc *BlockChain) AddBlock(newBlock *block.Block){
    if bc.Count == 0 {bc =  NewBlockChain()
    }
    // 判断新增区块是否无效
    if isValid(newBlock, bc){bc.Blocks = append(bc.Blocks, newBlock)
        bc.Count++
    }else{panic("invalid block")
    }
}

判断新增区块是否无效

func isValid(newBlock *block.Block, bc *BlockChain) bool {oldBlock := bc.Blocks[bc.Count - 1]
    if newBlock.Index - 1 != oldBlock.Index{return false}
    if newBlock.PrevBlockHash != oldBlock.PrevBlockHash{return false}
    if block.CalcHash(newBlock) != newBlock.Hash{return false}
    return true
}

写区块链并减少区块

func (bc *BlockChain) Write(data string){oldBlock := bc.Blocks[bc.Count - 1]
    newBlock := block.GenerateBlock(oldBlock, data)
    bc.AddBlock(newBlock)
}

打印区块链

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

测试

package main

import("BlockChain/blockChain")

func main(){bc := blockChain.NewBlockChain()

    bc.Write("first block")
    bc.Write("second block")
    bc.Print()}

$ go run main.go                                                                            
Index: 0 Timestamp: 1666286818 PrevBlockHash:  Data: Genesis Block Hash: 90d7d6d9adc8a6dd4eca1e30d8c1a8556a8e3e508da81f30a9e520c2ee7124b0
Index: 1 Timestamp: 1666286818 PrevBlockHash: 90d7d6d9adc8a6dd4eca1e30d8c1a8556a8e3e508da81f30a9e520c2ee7124b0 Data: first block Hash: 16f4d5551953062eca3e7858c28726967d6129f03ac393175efb6044e797589b
Index: 2 Timestamp: 1666286818 PrevBlockHash: 16f4d5551953062eca3e7858c28726967d6129f03ac393175efb6044e797589b Data: second block Hash: ad14b2a702a2a1d6765190c84128daca2fa350396b80e95aeb1aaa9e5c77aa11

关于go:Go-区块链实现

区块链七层架构模型

创立工程文件

数据层

hash

block

blockchain