Golang TxSimulator.SetState方法代碼示例

// TransferFunds simulates a transaction for transferring fund from fromAccount to toAccount
func (app *App) TransferFunds(fromAccount string, toAccount string, transferAmt int) (*common.Envelope, error) {
	// act as endorsing peer shim code to simulate a transaction on behalf of chaincode
	var txSimulator ledger.TxSimulator
	var err error
	if txSimulator, err = app.ledger.NewTxSimulator(); err != nil {
		return nil, err
	}
	defer txSimulator.Done()
	var balFromBytes []byte
	if balFromBytes, err = txSimulator.GetState(app.name, fromAccount); err != nil {
		return nil, err
	}
	balFrom := toInt(balFromBytes)
	if balFrom-transferAmt < 0 {
		return nil, fmt.Errorf("Not enough balance in account [%s]. Balance = [%d], transfer request = [%d]",
			fromAccount, balFrom, transferAmt)
	}

	var balToBytes []byte
	if balToBytes, err = txSimulator.GetState(app.name, toAccount); err != nil {
		return nil, err
	}
	balTo := toInt(balToBytes)
	txSimulator.SetState(app.name, fromAccount, toBytes(balFrom-transferAmt))
	txSimulator.SetState(app.name, toAccount, toBytes(balTo+transferAmt))
	var txSimulationResults []byte
	if txSimulationResults, err = txSimulator.GetTxSimulationResults(); err != nil {
		return nil, err
	}

	// act as endorsing peer to create an Action with the SimulationResults
	// then act as SDK to create a Transaction with the EndorsedAction
	tx := constructTransaction(txSimulationResults)
	return tx, nil
}

// CreateMarble simulates init transaction
func (marbleApp *MarbleApp) CreateMarble(args []string) (*common.Envelope, error) {
	//   0       1       2     3
	// "asdf", "blue", "35", "bob"
	logger.Debugf("===COUCHDB=== Entering ----------CreateMarble()----------")
	marbleName := args[0]
	marbleJsonBytes, err := init_marble(args)
	if err != nil {
		return nil, err
	}

	var txSimulator ledger.TxSimulator
	if txSimulator, err = marbleApp.ledger.NewTxSimulator(); err != nil {
		return nil, err
	}
	defer txSimulator.Done()

	txSimulator.SetState(marbleApp.name, marbleName, marbleJsonBytes)

	var txSimulationResults []byte
	if txSimulationResults, err = txSimulator.GetTxSimulationResults(); err != nil {
		return nil, err
	}
	logger.Debugf("===COUCHDB=== CreateMarble() simulation done, packaging into a transaction...")
	tx := constructTransaction(txSimulationResults)
	logger.Debugf("===COUCHDB=== Exiting CreateMarble()")
	return tx, nil
}

// TransferMarble simulates transfer transaction
func (marbleApp *MarbleApp) TransferMarble(args []string) (*common.Envelope, error) {
	//   0       1
	// "name", "bob"
	if len(args) < 2 {
		return nil, errors.New("Incorrect number of arguments. Expecting 2")
	}
	marbleName := args[0]
	marbleNewOwner := args[1]

	logger.Debugf("===COUCHDB=== Entering ----------TransferMarble----------")
	var txSimulator ledger.TxSimulator
	var err error
	if txSimulator, err = marbleApp.ledger.NewTxSimulator(); err != nil {
		return nil, err
	}
	defer txSimulator.Done()

	marbleBytes, err := txSimulator.GetState(marbleApp.name, marbleName)
	logger.Debugf("===COUCHDB=== marbleBytes is: %v", marbleBytes)
	if marbleBytes != nil {
		jsonString := string(marbleBytes[:])
		logger.Debugf("===COUCHDB=== TransferMarble() Retrieved jsonString: \n   %s", jsonString)
	}

	theMarble := Marble{}
	json.Unmarshal(marbleBytes, &theMarble) //Unmarshal JSON bytes into a Marble struct

	logger.Debugf("===COUCHDB===  theMarble after unmarshal: %v", theMarble)

	logger.Debugf("===COUCHDB===  Setting the owner to: %s", marbleNewOwner)
	theMarble.User = marbleNewOwner      //change the user
	theMarble.Txid = "tx000000000000002" // COUCHDB hardcode a txid for now for demo purpose

	updatedMarbleBytes, _ := json.Marshal(theMarble)
	if updatedMarbleBytes != nil {
		updatedJsonString := string(updatedMarbleBytes[:])
		logger.Debugf("===COUCHDB=== updatedJsonString:\n   %s", updatedJsonString)
	}
	err = txSimulator.SetState(marbleApp.name, marbleName, updatedMarbleBytes)
	if err != nil {
		return nil, err
	}

	var txSimulationResults []byte
	if txSimulationResults, err = txSimulator.GetTxSimulationResults(); err != nil {
		return nil, err
	}
	logger.Debugf("===COUCHDB=== TransferMarble() simulation done, packaging into a transaction...")
	tx := constructTransaction(txSimulationResults)
	return tx, nil
}

// Init simulates init transaction
func (app *App) Init(initialBalances map[string]int) (*common.Envelope, error) {
	var txSimulator ledger.TxSimulator
	var err error
	if txSimulator, err = app.ledger.NewTxSimulator(); err != nil {
		return nil, err
	}
	defer txSimulator.Done()
	for accountID, bal := range initialBalances {
		txSimulator.SetState(app.name, accountID, toBytes(bal))
	}
	var txSimulationResults []byte
	if txSimulationResults, err = txSimulator.GetTxSimulationResults(); err != nil {
		return nil, err
	}
	tx := constructTransaction(txSimulationResults)
	return tx, nil
}