go:实现最简单区块链

1.新建文件夹命名为blockchain,在此文件夹下分别创建两个文件一个为block.go另一个为chain.go如下图所示:

2.写入代码:

block.go

package blockchain

import (
    "bytes"
    "crypto/sha256"
    "encoding/gob"
    "log"
    "strconv"
    "time"
)

type Block struct {
    Index         int64
    TimeStamp     int64
    Data          []byte
    PrevBlockHash []byte
    Hash          []byte
}

func (b *Block) setHash() {
    timestamp := []byte(strconv.FormatInt(b.TimeStamp, 10))
    index := []byte(strconv.FormatInt(b.Index, 10))
    headers := bytes.Join([][]byte{timestamp, index, b.Data, b.PrevBlockHash}, []byte{})
    hash := sha256.Sum256(headers)
    b.Hash = hash[:]
}
func (b *Block) SerializeToBytes() []byte {
    var result bytes.Buffer
    encoder := gob.NewEncoder(&result)
    err := encoder.Encode(b)
    if err != nil {
        log.Panic(err)
    }
    return result.Bytes()

}
func (b *Block) DeserializeFromBytes(d []byte) *Block {
    var block Block
    decoder := gob.NewDecoder(bytes.NewReader(d))
    err := decoder.Decode(&block)
    if err != nil {
        log.Panic(err)
    }
    return &block
}
func NewBlock(index int64, data, prevBlockHash []byte) *Block {
    block := &Block{index, time.Now().Unix(), data, prevBlockHash, []byte{}}
    block.setHash() //设置当前区块Hash
    return block
}

// NewGenesisBlock 生成创世区块，区块链第一个结点
func NewGenesisBlock() *Block {
    return NewBlock(0, []byte("first block"), []byte{})
}

chain.go

package blockchain
// Blockchain 区块链结构定义
type Blockchain struct {
Blocks []*Block
}
// AddBlock 添加一个区块到区块链，上链
func (bc *Blockchain) AddBlock(data string) {
prevBlock := bc.Blocks[len(bc.Blocks)-1]
newBlock := NewBlock(prevBlock.Index+1, []byte(data), prevBlock.Hash)
bc.Blocks = append(bc.Blocks, newBlock)
}
// NewBlockchain 生成一个新的区块链实例
func NewBlockchain() *Blockchain {
return &Blockchain{[]*Block{NewGenesisBlock()}}
}

3.在外部main.go中调用blockchain这个包

package main

import (
    "block/blockchain"
    "fmt"
)

func main() {
    fmt.Println("go语言最简区块链原理测试")
    fmt.Println("_____________________________")
    bc := blockchain.NewBlockchain()
    bc.AddBlock("这是第一个区块的内容")
    bc.AddBlock("这是第二个区块的内容")
    bc.AddBlock("某班级上课；202x年x月x日，实到xx人")
    for _, block := range bc.Blocks {
        fmt.Printf("Index :%d\n", block.Index)
        fmt.Printf("TimeStamp: %d\n", block.TimeStamp)
        fmt.Printf("Data: %s\n", block.Data)
        fmt.Printf("Hash: %x\n", block.Hash)
        fmt.Printf("PrevHash: %x\n", block.PrevBlockHash)
        fmt.Println("_____________________________")
    }
}

运行结果