What is the development of the spot options contract exchange system丨Detailed technology for the development of the spot options contract exchange system

func handleGetBlockchain(w http.ResponseWriter, r *http.Request) {
    bytes, err := json.MarshalIndent(Blockchain, "", "  ")
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }
    io.WriteString(w, string(bytes))
}

func handleWriteBlock(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "application/json")

    //使用了一个Mesage结构体,more convenient storageBPM
    var msg Message

    //Receive the requested data information,类似{"BPM":60}这样的格式
    decoder := json.NewDecoder(r.Body)
    if err := decoder.Decode(&msg); err != nil {
        respondWithJSON(w, r, http.StatusBadRequest, r.Body)
        return
    }
    defer r.Body.Close()

    //控制并发,生成区块链,并且校验
    mutex.Lock()
    prevBlock := Blockchain[len(Blockchain)-1]
    newBlock := generateBlock(prevBlock, msg.BPM)

    //Check the blockchain
    if isBlockValid(newBlock, prevBlock) {
        Blockchain = append(Blockchain, newBlock)
        spew.Dump(Blockchain)
    }
    mutex.Unlock()

    //Returns new block information
    respondWithJSON(w, r, http.StatusCreated, newBlock)

}

// Message takes incoming JSON payload for writing heart rate
type Message struct {
    BPM int
}

func respondWithJSON(w http.ResponseWriter, r *http.Request, code int, payload interface{}) {
    response, err := json.MarshalIndent(payload, "", "  ")
    if err != nil {
        w.WriteHeader(http.StatusInternalServerError)
        w.Write([]byte("HTTP 500: Internal Server Error"))
        return
    }
    w.WriteHeader(code)
    w.Write(response)
}

// web server
func run() error {
    mux := makeMuxRouter()
    //Read the listening port from the configuration file
    httpPort := os.Getenv("PORT")
    log.Println("HTTP Server Listening on port :", httpPort)
    s := &http.Server{
        Addr:           ":" + httpPort,
        Handler:        mux,
        ReadTimeout:    10 * time.Second,
        WriteTimeout:   10 * time.Second,
        MaxHeaderBytes: 1 << 20,
    }

    if err := s.ListenAndServe(); err != nil {
        return err
    }

    return nil
}

//控制并发的锁
var mutex = &sync.Mutex{}

func main() {
    //加载env配置文件
    err := godotenv.Load()
    if err != nil {
        log.Fatal(err)
    }

    //开启一个goroutineGenerate a genesis block
    go func() {
        t := time.Now()
        genesisBlock := Block{}
        genesisBlock = Block{0, t.String(), 0, calculateHash(genesisBlock), ""}
        spew.Dump(genesisBlock)

        mutex.Lock()
        Blockchain = append(Blockchain, genesisBlock)
        mutex.Unlock()
    }()
    log.Fatal(run())

}