数字货币发行与管理
简介
该智能合约实现一个简单的商业应用案例，即数字货币的发行与转账。在这之中一共分为三种角色：中央银行，商业银行，企业。其中中央银行可以发行一定数量的货币，企业之间可以进行相互的转账。主要实现如下的功能：
- 初始化中央银行及其发行的货币数量
- 新增商业银行，同时央行并向其发行一定数量的货币
- 新增企业
- 商业银行向企业转给一定数量的数字货币
- 企业之间进行相互的转账
- 查询企业、银行、交易信息
主要函数
init：初始化中央银行，并发行一定数量的货币；invoke：调用合约内部的函数；query：查询相关的信息；createBank：新增商业银行，同时央行向其发行一定数量的货币；createCompany：新增企业；issueCoin：央行再次发行一定数量的货币（归于交易）；issueCoinToBank：央行向商业银行转一定数量的数字货币（归于交易）；issueCoinToCp：商业银行向企业转一定数量的数字货币（归于交易行为）；transfer：企业之间进行相互转账（归于交易行为）；getCompanys：获取所有的公司信息，如果企业个数大于10，先访问前10个；getBanks：获取所有的商业银行信息，如果商业银行个数大于10，先访问前 10 个getTransactions：获取所有的交易记录 如果交易个数大于10，先访问前 10 个；getCompanyById：获取某家公司信息；getBankById：获取某家银行信息；getTransactionBy：获取某笔交易记录；writeCenterBank：修改央行信息；writeBank：修改商业银行信息；writeCompany：修改企业信息；writeTransaction：写入交易信息。
数据结构设计
- centerBank 中央银行
- Name：名称
- TotalNumber：发行货币总数额
- RestNumber：账户余额
- ID：ID固定为 0
- bank 商业银行
- Name：名称
- TotalNumber：收到货币总数额
- RestNumber：账户余额
- ID：银行 ID
- company 企业
- Name：名称
- Number：账户余额
- ID：企业 ID
- transaction 交易内容
- FromType：发送方角色 //centerBank:0,Bank:1,Company:2
- FromID：发送方 ID
- ToType：接收方角色 //Bank:1,Company:2
- ToID：接收方 ID
- Time：交易时间
- Number：交易数额
- ID：交易 ID
接口设计
init
request 参数:
args[0] 银行名称
args[1] 初始化发布金额response 参数:
{"Name":"XXX","TotalNumber":"0","RestNumber":"0","ID":"XX"}createBank
request 参数:
args[0] 银行名称response 参数:
{"Name":"XXX","TotalNumber":"0","RestNumber":"0","ID":"XX"}createCompany
request 参数:
args[0] 公司名称response 参数:
{"Name":"XXX","Number":"0","ID":"XX"}issueCoin
request 参数:
args[0] 再次发行货币数额
response 参数:
{"FromType":"0","FromID":"0","ToType":"0","ToID":"0","Time":"XX","Number":"XX","ID":"XX"}issueCoinToBank
request 参数:
args[0] 商业银行ID
args[1] 转账数额response 参数:
{"FromType":"0","FromID":"0","ToType":"1","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}issueCoinToCp
request 参数:
args[0] 商业银行ID
args[1] 企业ID
args[2] 转账数额
response 参数:
{"FromType":"1","FromID":"XX","ToType":"2","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}transfer
request 参数:
args[0] 转账用户ID
args[1] 被转账用户ID
args[2] 转账余额response 参数:
{"FromType":"2","FromID":"XX","ToType":"2","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}getBanks
response 参数
[{"Name":"XXX","Number":"XX","ID":"XX"},{"Name":"XXX","Number":"XX","ID":"XX"},...]getCompanys
response 参数
[{"Name":"XXX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"},{"Name":"XXX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"},...]getTransactions
response 参数
[{"FromType":"XX","FromID":"XX","ToType":"XX","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"},{"FromType":"XX","FromID":"XX","ToType":"XX","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"},...]getCenterBank
response 参数
[{"Name":"XX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"}]getBankById
request 参数
args[0] 商业银行IDresponse 参数
[{"Name":"XX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"}]getCompanyById
request 参数
args[0] 企业IDresponse 参数
[{"Name":"XXX","Number":"XX","ID":"XX"}]getTransactionById
request 参数
args[0] 交易IDresponse 参数
{"FromType":"XX","FromID":"XX","ToType":"XX","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}writeCenterBank
request 参数
CenterBankresponse 参数
err nil 为成功writeBank
request 参数
Bankresponse 参数
err nil 为成功writeCompany
request 参数
Companyresponse 参数
err nil 为成功writeTransaction
request 参数
Transactionresponse 参数
err nil 为成功其它
查询时为了兼顾读速率，将一些信息备份存放在非区块链数据库上也是一个较好的选择。
/*
author:swb
time:16/7/05
MIT License
*/
package main
import (
"encoding/json"
"errors"
"fmt"
"strconv"
"time"
"github.com/hyperledger/fabric/core/chaincode/shim"
)
var bankNo int = 0
var cpNo int = 0
var transactionNo int = 0
// SimpleChaincode example simple Chaincode implementation
type SimpleChaincode struct {
}
type CenterBank struct {
Name string
TotalNumber int
RestNumber int
}
type Bank struct {
Name string
TotalNumber int
RestNumber int
ID int
}
type Company struct {
Name string
Number int
ID int
}
type Transaction struct {
FromType int //CenterBank 0 Bank 1 Company 1
FromID int
ToType int //Bank 1 Company 2
ToID int
Time int64
Number int
ID int
}
func main() {
err := shim.Start(new(SimpleChaincode))
if err != nil {
fmt.Printf("Error starting Simple chaincode: %s", err)
}
}
// Init resets all the things
func (t *SimpleChaincode) Init(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
if len(args) != 2 {
return nil, errors.New("Incorrect number of arguments. Expecting 2")
}
var totalNumber int
var centerBank CenterBank
var cbBytes []byte
totalNumber, err := strconv.Atoi(args[1])
if err != nil {
return nil, errors.New("Expecting integer value for asset holding")
}
centerBank = CenterBank{Name: args[0], TotalNumber: totalNumber, RestNumber: 0}
err = writeCenterBank(stub,centerBank)
if err != nil {
return nil, errors.New("write Error" + err.Error())
}
cbBytes,err = json.Marshal(¢erBank)
if err!= nil{
return nil,errors.New("Error retrieving cbBytes")
}
return cbBytes, nil
}
// Invoke isur entry point to invoke a chaincode function
func (t *SimpleChaincode) Invoke(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
if function == "createBank" {
return t.createBank(stub, args)
} else if function == "createCompany" {
return t.createCompany(stub, args)
} else if function == "issueCoin" {
return t.issueCoin(stub, args)
} else if function == "issueCoinToBank" {
return t.issueCoinToBank(stub, args)
} else if function == "issueCoinToCp" {
return t.issueCoinToCp(stub, args)
} else if function =="transfer"{
return t.transfer(stub,args)
}
return nil, errors.New("Received unknown function invocation")
}
func (t *SimpleChaincode) createBank(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting 1")
}
var bank Bank
var bankBytes []byte
var centerBank CenterBank
bank = Bank{Name:args[0],TotalNumber:0,RestNumber:0,ID:bankNo}
err := writeCenterBank(stub,centerBank)
if err != nil {
return nil, errors.New("write Error" + err.Error())
}
bankBytes,err = json.Marshal(&bank)
if err!= nil{
return nil,errors.New("Error retrieving cbBytes")
}
bankNo = bankNo +1
return bankBytes, nil
}
func (t *SimpleChaincode) createCompany(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting 1")
}
var company Company
company = Company{Name:args[0],Number:0,ID:cpNo}
err := writeCompany(stub,company)
if err != nil{
return nil, errors.New("write Error" + err.Error())
}
cpBytes,err := json.Marshal(&company)
if(err!=nil){
return nil,err
}
cpNo = cpNo +1
return cpBytes, nil
}
func (t *SimpleChaincode) issueCoin(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting 1")
}
var centerBank CenterBank
var tsBytes []byte
issueNumber ,err:= strconv.Atoi(args[0])
if err!=nil{
return nil,errors.New("want Integer number")
}
centerBank,_,err = getCenterBank(stub)
if err !=nil{
return nil,errors.New("get errors")
}
centerBank.TotalNumber = centerBank.TotalNumber + issueNumber
centerBank.RestNumber = centerBank.RestNumber + issueNumber
err = writeCenterBank(stub,centerBank)
if err != nil {
return nil, errors.New("write Error" + err.Error())
}
transaction := Transaction{FromType:0,FromID:0,ToType:0,ToID:0,Time:time.Now().Unix(),Number:issueNumber,ID:transactionNo}
err = writeTransaction(stub,transaction)
if err != nil {
return nil, errors.New("write Error" + err.Error())
}
tsBytes,err = json.Marshal(&transaction)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
transactionNo = transactionNo +1
return tsBytes, nil
}
func (t *SimpleChaincode) issueCoinToBank(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
if len(args) != 2 {
return nil, errors.New("Incorrect number of arguments. Expecting 2")
}
var centerBank CenterBank
var bank Bank
var bankId string
var issueNumber int
var tsBytes []byte
var err error
var bankIdInt int
bankId = args[0]
bankIdInt,err = strconv.Atoi(args[0])
if err!=nil{
return nil,errors.New("want Integer number")
}
issueNumber,err = strconv.Atoi(args[1])
if err!=nil{
return nil,errors.New("want Integer number")
}
centerBank,_,err = getCenterBank(stub)
if err !=nil{
return nil,errors.New("get errors")
}
if centerBank.RestNumber<issueNumber{
return nil,errors.New("Not enough money")
}
bank,_,err = getBankById(stub,bankId)
if err != nil {
return nil,errors.New("get errors")
}
bank.RestNumber = bank.RestNumber + issueNumber
bank.TotalNumber = bank.TotalNumber + issueNumber
centerBank.RestNumber = centerBank.RestNumber - issueNumber
err = writeCenterBank(stub,centerBank)
if err != nil {
bank.RestNumber = bank.RestNumber - issueNumber
bank.TotalNumber = bank.TotalNumber - issueNumber
centerBank.RestNumber = centerBank.RestNumber + issueNumber
return nil, errors.New("write errors"+err.Error())
}
err = writeBank(stub,bank)
if err != nil {
bank.RestNumber = bank.RestNumber - issueNumber
bank.TotalNumber = bank.TotalNumber - issueNumber
centerBank.RestNumber = centerBank.RestNumber + issueNumber
err = writeCenterBank(stub,centerBank)
if err != nil {
return nil, errors.New("roll down errors"+err.Error())
}
return nil, err
}
transaction := Transaction{FromType:0,FromID:0,ToType:1,ToID:bankIdInt,Time:time.Now().Unix(),Number:issueNumber,ID:transactionNo}
err = writeTransaction(stub,transaction)
if err != nil {
return nil, errors.New("write Error" + err.Error())
}
tsBytes,err = json.Marshal(&transaction)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
transactionNo = transactionNo +1
return tsBytes, nil
}
func (t *SimpleChaincode) issueCoinToCp(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
if len(args) != 3 {
return nil, errors.New("Incorrect number of arguments. Expecting 3")
}
var company Company
var bank Bank
var bankId string
var bankIdInt int
var companyId string
var companyIdInt int
var issueNumber int
var tsBytes []byte
var err error
bankId = args[0]
bankIdInt,err = strconv.Atoi(args[0])
if err!=nil{
return nil,errors.New("want integer")
}
companyId = args[1]
companyIdInt,err = strconv.Atoi(args[1])
if err!=nil{
return nil,errors.New("want integer")
}
issueNumber,err= strconv.Atoi(args[2])
if err!=nil{
return nil,errors.New("want integer")
}
bank,_,err = getBankById(stub,bankId)
if err != nil {
return nil,errors.New("get errors")
}
if bank.RestNumber<issueNumber{
return nil,errors.New("Not enough money")
}
company,_,err = getCompanyById(stub,companyId)
if err != nil {
return nil,errors.New("get errors")
}
bank.RestNumber = bank.RestNumber - issueNumber
company.Number = company.Number + issueNumber
err = writeBank(stub,bank)
if err != nil {
bank.RestNumber = bank.RestNumber + issueNumber
company.Number = company.Number - issueNumber
return nil, err
}
err = writeCompany(stub,company)
if err != nil {
bank.RestNumber = bank.RestNumber + issueNumber
company.Number = company.Number - issueNumber
err = writeBank(stub,bank)
if err != nil {
return nil, errors.New("roll down errors"+err.Error())
}
return nil, err
}
transaction := Transaction{FromType:1,FromID:bankIdInt,ToType:1,ToID:companyIdInt,Time:time.Now().Unix(),Number:issueNumber,ID:transactionNo}
err = writeTransaction(stub,transaction)
if err != nil {
return nil, errors.New("write Error" + err.Error())
}
tsBytes,err = json.Marshal(&transaction)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
transactionNo = transactionNo +1
return tsBytes, nil
}
func (t *SimpleChaincode) transfer(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
if len(args) != 3 {
return nil, errors.New("Incorrect number of arguments. Expecting 3")
}
var cpFrom Company
var cpTo Company
var cpFromId string
var cpFromIdInt int
var cpToId string
var cpToIdInt int
var issueNumber int
var tsBytes [] byte
var err error
cpFromId = args[0]
cpFromIdInt,err = strconv.Atoi(args[0])
if err!=nil{
return nil,errors.New("want integer")
}
cpToId = args[1]
cpToIdInt,err = strconv.Atoi(args[1])
if err!=nil{
return nil,errors.New("want integer")
}
issueNumber,err = strconv.Atoi(args[2])
if err != nil {
return nil, errors.New("Expecting integer value for asset holding")
}
cpFrom,_,err = getCompanyById(stub,cpFromId)
if err != nil {
return nil,errors.New("get errors")
}
if cpFrom.Number<issueNumber{
return nil,errors.New("Not enough money")
}
cpTo,_,err = getCompanyById(stub,cpToId)
if err != nil {
return nil,errors.New("get errors")
}
cpFrom.Number = cpFrom.Number - issueNumber
cpTo.Number = cpTo.Number + issueNumber
err = writeCompany(stub,cpFrom)
if err != nil {
cpFrom.Number = cpFrom.Number - issueNumber
cpTo.Number = cpTo.Number + issueNumber
return nil, errors.New("write Error" + err.Error())
}
err = writeCompany(stub,cpTo)
if err != nil {
cpFrom.Number = cpFrom.Number - issueNumber
cpTo.Number = cpTo.Number + issueNumber
err = writeCompany(stub,cpFrom)
if err !=nil{
return nil,errors.New("roll down error")
}
return nil, errors.New("write Error" + err.Error())
}
transaction := Transaction{FromType:2,FromID:cpFromIdInt,ToType:2,ToID:cpToIdInt,Time:time.Now().Unix(),Number:issueNumber,ID:transactionNo}
err = writeTransaction(stub,transaction)
if err != nil {
return nil, errors.New("write Error" + err.Error())
}
tsBytes,err = json.Marshal(&transaction)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
transactionNo = transactionNo +1
return tsBytes, nil
}
// Query is our entry point for queries
func (t *SimpleChaincode) Query(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
fmt.Println("query is running " + function)
if function == "getCenterBank" {
if len(args) != 0 {
return nil, errors.New("Incorrect number of arguments. Expecting 0")
}
_,cbBytes, err := getCenterBank(stub)
if err != nil {
fmt.Println("Error get centerBank")
return nil, err
}
return cbBytes, nil
} else if function == "getBankById" {
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting 0")
}
_,bankBytes, err := getBankById(stub, args[0])
if err != nil {
fmt.Println("Error unmarshalling centerBank")
return nil, err
}
return bankBytes, nil
} else if function == "getCompanyById" {
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting 0")
}
_,cpBytes, err := getCompanyById(stub, args[0])
if err != nil {
fmt.Println("Error unmarshalling centerBank")
return nil, err
}
return cpBytes, nil
} else if function == "getTransactionById" {
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting 0")
}
_,tsBytes, err := getTransactionById(stub, args[0])
if err != nil {
fmt.Println("Error unmarshalling")
return nil, err
}
return tsBytes, nil
} else if function == "getBanks" {
if len(args) != 0 {
return nil, errors.New("Incorrect number of arguments. Expecting 0")
}
banks, err := getBanks(stub)
if err != nil {
fmt.Println("Error unmarshalling")
return nil, err
}
bankBytes, err1 := json.Marshal(&banks)
if err1 != nil {
fmt.Println("Error marshalling banks")
}
return bankBytes, nil
} else if function == "getCompanys" {
if len(args) != 0 {
return nil, errors.New("Incorrect number of arguments. Expecting 0")
}
cps, err := getCompanys(stub)
if err != nil {
fmt.Println("Error unmarshalling")
return nil, err
}
cpBytes, err1 := json.Marshal(&cps)
if err1 != nil {
fmt.Println("Error marshalling banks")
}
return cpBytes, nil
} else if function == "getTransactions" {
if len(args) != 0 {
return nil, errors.New("Incorrect number of arguments. Expecting 0")
}
tss, err := getTransactions(stub)
if err != nil {
fmt.Println("Error unmarshalling")
return nil, err
}
tsBytes, err1 := json.Marshal(&tss)
if err1 != nil {
fmt.Println("Error marshalling banks")
}
return tsBytes, nil
}
return nil,nil
}
func getCenterBank(stub *shim.ChaincodeStub) (CenterBank, []byte,error) {
var centerBank CenterBank
cbBytes, err := stub.GetState("centerBank")
if err != nil {
fmt.Println("Error retrieving cbBytes")
}
err = json.Unmarshal(cbBytes, ¢erBank)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
return centerBank,cbBytes, nil
}
func getCompanyById(stub *shim.ChaincodeStub, id string) (Company,[]byte, error) {
var company Company
cpBytes,err := stub.GetState("company"+id)
if err != nil {
fmt.Println("Error retrieving cpBytes")
}
err = json.Unmarshal(cpBytes, &company)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
return company,cpBytes, nil
}
func getBankById(stub *shim.ChaincodeStub, id string) (Bank, []byte,error) {
var bank Bank
cbBytes,err := stub.GetState("bank"+id)
if err != nil {
fmt.Println("Error retrieving cpBytes")
}
err = json.Unmarshal(cbBytes, &bank)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
return bank,cbBytes, nil
}
func getTransactionById(stub *shim.ChaincodeStub, id string) (Transaction,[]byte, error) {
var transaction Transaction
tsBytes,err := stub.GetState("transaction"+id)
if err != nil {
fmt.Println("Error retrieving cpBytes")
}
err = json.Unmarshal(tsBytes, &transaction)
if err != nil {
fmt.Println("Error unmarshalling centerBank")
}
return transaction,tsBytes, nil
}
func getBanks(stub *shim.ChaincodeStub) ([]Bank, error) {
var banks []Bank
var number string
var err error
var bank Bank
if bankNo<=10 {
i:=0
for i<bankNo {
number= strconv.Itoa(i)
bank,_, err = getBankById(stub, number)
if err != nil {
return nil, errors.New("Error get detail")
}
banks = append(banks,bank)
i = i+1
}
} else{
i:=0
for i<10{
number=strconv.Itoa(i)
bank,_, err = getBankById(stub, number)
if err != nil {
return nil, errors.New("Error get detail")
}
banks = append(banks,bank)
i = i+1
}
return banks, nil
}
return nil,nil
}
func getCompanys(stub *shim.ChaincodeStub) ([]Company, error) {
var companys []Company
var number string
var err error
var company Company
if cpNo<=10 {
i:=0
for i<bankNo {
number=strconv.Itoa(i)
company,_ ,err = getCompanyById(stub,number)
if err != nil {
return nil, errors.New("Error get detail")
}
companys = append(companys,company)
i = i+1
}
} else{
i:=0
for i<10{
number=strconv.Itoa(i)
company,_ ,err = getCompanyById(stub,number)
if err != nil {
return nil, errors.New("Error get detail")
}
companys = append(companys,company)
i = i+1
}
return companys, nil
}
return nil,nil
}
func getTransactions(stub *shim.ChaincodeStub) ([]Transaction, error) {
var transactions []Transaction
var number string
var err error
var transaction Transaction
if transactionNo<=10 {
i:=0
for i<transactionNo {
number=strconv.Itoa(i)
transaction,_ ,err = getTransactionById(stub,number)
if err != nil {
return nil, errors.New("Error get detail")
}
transactions = append(transactions,transaction)
i = i+1
}
} else{
i:=0
for i<10{
number=strconv.Itoa(i)
transaction,_ ,err = getTransactionById(stub,number)
if err != nil {
return nil, errors.New("Error get detail")
}
transactions = append(transactions,transaction)
i = i+1
}
return transactions, nil
}
return nil,nil
}
func writeCenterBank(stub *shim.ChaincodeStub,centerBank CenterBank) (error) {
cbBytes, err := json.Marshal(¢erBank)
if err != nil {
return err
}
err = stub.PutState("centerBank", cbBytes)
if err != nil {
return errors.New("PutState Error" + err.Error())
}
return nil
}
func writeBank(stub *shim.ChaincodeStub,bank Bank) (error) {
var bankId string
bankBytes, err := json.Marshal(&bank)
if err != nil {
return err
}
bankId= strconv.Itoa(bank.ID)
if err!= nil{
return errors.New("want Integer number")
}
err = stub.PutState("bank"+bankId, bankBytes)
if err != nil {
return errors.New("PutState Error" + err.Error())
}
return nil
}
func writeCompany(stub *shim.ChaincodeStub,company Company) (error) {
var companyId string
cpBytes, err := json.Marshal(&company)
if err != nil {
return err
}
companyId= strconv.Itoa(company.ID)
if err!= nil{
return errors.New("want Integer number")
}
err = stub.PutState("company"+companyId, cpBytes)
if err != nil {
return errors.New("PutState Error" + err.Error())
}
return nil
}
func writeTransaction(stub *shim.ChaincodeStub,transaction Transaction) (error) {
var tsId string
tsBytes, err := json.Marshal(&transaction)
if err != nil {
return err
}
tsId= strconv.Itoa(transaction.ID)
if err!= nil{
return errors.New("want Integer number")
}
err = stub.PutState("transaction"+tsId, tsBytes)
if err != nil {
return errors.New("PutState Error" + err.Error())
}
return nil
}最后编辑: kuteng 文档更新时间: 2023-05-04 16:28 作者：kuteng
