如何在链码中编写一个函数，简单地计算总记录数并返回总number.hyperledger fabric

package main

import (
    "fmt"

    "github.com/hyperledger/fabric/core/chaincode/shim"
    "github.com/hyperledger/fabric/protos/peer"
)

type MyChaincode struct {
}

func (cc *MyChaincode) Init(stub shim.ChaincodeStubInterface) peer.Response {
    return shim.Success(nil)
}

func (cc *MyChaincode) Invoke(stub shim.ChaincodeStubInterface) peer.Response {
    function, args := stub.GetFunctionAndParameters()

    if function == "getTotalRecords" {
        return cc.getTotalRecords(stub, args)
    }

    return shim.Error("Invalid function name")
}

func (cc *MyChaincode) getTotalRecords(stub shim.ChaincodeStubInterface, args []string) peer.Response {
    // 在这里编写计算总记录数的逻辑
    // 假设记录存储在一个名为"records"的状态变量中
    recordsBytes, err := stub.GetState("records")
    if err != nil {
        return shim.Error("Failed to get records: " + err.Error())
    }

    totalRecords := len(recordsBytes)

    return shim.Success([]byte(fmt.Sprintf("Total records: %d", totalRecords)))
}

func main() {
    err := shim.Start(new(MyChaincode))
    if err != nil {
        fmt.Printf("Error starting chaincode: %s", err)
    }
}