本文主要利用 Go 语言对区块链模型进行了简单的实现，通过 GoLand 创建链式结构和一个简单的 http server，对外暴露读写接口，运行 rpc 并以地址访问形式向区块链发送数据和读取数据。

简单区块链的实现大致步骤分为：

（1）创建 Block
（2）创建 Blockchain
（3）创建 Http server

在实现之前，首先通过 GoLand 创建 blockchainDemo 项目，并建立对应的 Block.go、Blockchain.go 以及 Server.go 文件，具体的目录如下。

一、创建 Block

  • 创建 Block 文件
  • 创建 Block 结构体与相关函数
package coreimport ( "crypto/sha256" "encoding/hex" "time")type Block struct { Index int64// 区块编号 Timestamp int64// 区块时间戳 PrevBlochHash string // 上一个区块哈希值 Hashstring // 当前区块哈希值 Data string // 区块数据}// calculateHash 计算哈希值func calculateHash(b Block) string { blockData := string(b.Index) + string(b.Timestamp) + b.PrevBlochHash + b.Data hashInBytes := sha256.Sum256([]byte(blockData)) return hex.EncodeToString(hashInBytes[:])}// GenerateNewBlock 创建新区块func GenerateNewBlock(preBlock Block, data string) Block { newBlock := Block{} newBlock.Index = preBlock.Index + 1 newBlock.PrevBlochHash = preBlock.Hash newBlock.Timestamp = time.Now().Unix() newBlock.Data = data newBlock.Hash = calculateHash(newBlock) return newBlock}// GenerateGenesisBlock 创建世纪区块func GenerateGenesisBlock() Block { preBlock := Block{} preBlock.Index = -1 preBlock.Hash = "" return GenerateNewBlock(preBlock, "Genesis Block")}

这里需要注意的是，在创建世纪区块时，考虑到对 GenerateNewBlock 函数的复用，因此，创建了一个 preBlock 来辅助世纪块的创建，实际区块链上世纪块前面不存在其他区块，且世纪块以 0 作为索引。

二、创建 Blockchain

  • 创建 Blockchain 文件
  • 创建 Blockchain 结构体及相关方法
package coreimport ( "fmt" "log")type Blockchain struct { Blocks []*Block}// CreateBlockchain 创建区块链func CreateBlockchain() *Blockchain { genesisBlock := GenerateGenesisBlock() blockchain := Blockchain{} blockchain.AppendBlock(&genesisBlock) return &blockchain}// SendData 向区块链添加数据func (bc *Blockchain) SendData(data string) { preBlock := bc.Blocks[len(bc.Blocks)-1] newBlock := GenerateNewBlock(*preBlock, data) bc.AppendBlock(&newBlock)}// AppendBlock 向区块链添加新区块func (bc *Blockchain) AppendBlock(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") }}// 判断新添加的区块是否合法func isValid(newBlock Block, oldBlock Block) bool { if newBlock.Index-1 != oldBlock.Index {return false } if newBlock.PrevBlochHash != oldBlock.Hash {return false } if calculateHash(newBlock) != newBlock.Hash {return false } return true}// Print 对区块链上的区块内容进行打印func (bc *Blockchain) Print() { for _, block := range bc.Blocks {fmt.Printf("Index: %d\n", block.Index)fmt.Printf("Prev.Hash: %s\n", block.PrevBlochHash)fmt.Printf("Curr.Hash: %s\n", block.Hash)fmt.Printf("Data: %s\n", block.Data)fmt.Printf("Timestamp: %d\n", block.Timestamp) }}

三、创建 Http server

  • 创建 http server
  • 提供 API 访问接口
package mainimport ( "blockchainDemo/core" "encoding/json" "io" "net/http")var blockchain *core.Blockchainfunc run() { http.HandleFunc("/blockchain/get", blockchainGetHandler) http.HandleFunc("/blockchain/write", blockchainWriteHandler) http.ListenAndServe("localhost:8888", nil)}// 读接口func blockchainGetHandler(w http.ResponseWriter, r *http.Request) { bytes, err := json.Marshal(blockchain) if err != nil {http.Error(w, err.Error(), http.StatusInternalServerError)return } io.WriteString(w, string(bytes))}// 写接口func blockchainWriteHandler(w http.ResponseWriter, r *http.Request) { blockData := r.URL.Query().Get("data") blockchain.SendData(blockData) blockchainGetHandler(w, r)}func main() { blockchain = core.CreateBlockchain() run()}

四、模型测试

在 GoLand 上运行 http server，从代码中可知监听端口为 8888，因此，读写操作对应的地址是：

  • http://localhost:8888/blockchain/get
  • http://localhost:8888/blockchain/write" />// 网页显示效果{"Blocks":[{"Index":0,"Timestamp":1674227301,"PrevBlochHash":"","Hash":"90d7d6d9adc8a6dd4eca1e30d8c1a8556a8e3e508da81f30a9e520c2ee7124b0","Data":"Genesis Block"},{"Index":1,"Timestamp":1674227338,"PrevBlochHash":"90d7d6d9adc8a6dd4eca1e30d8c1a8556a8e3e508da81f30a9e520c2ee7124b0","Hash":"1a7c54ce0eaba45d5591640925405d90e74d9da5fa919b4e6eefa2447b2a4fb0","Data":"Send 1 BTC to Me"}]}