Golang ChaincodeStub.GetState方法代碼示例

// ============================================================================================================================
// Set User Permission on Marble
// ============================================================================================================================
func (t *SimpleChaincode) set_user(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
	var err error

	//   0       1
	// "name", "bob"
	if len(args) < 2 {
		return nil, errors.New("Incorrect number of arguments. Expecting 2")
	}

	fmt.Println("- start set user")
	fmt.Println(args[0] + " - " + args[1])
	marbleAsBytes, err := stub.GetState(args[0])
	if err != nil {
		return nil, errors.New("Failed to get thing")
	}
	res := Marble{}
	json.Unmarshal(marbleAsBytes, &res) //un stringify it aka JSON.parse()
	res.User = args[1]                  //change the user

	jsonAsBytes, _ := json.Marshal(res)
	err = stub.PutState(args[0], jsonAsBytes) //rewrite the marble with id as key
	if err != nil {
		return nil, err
	}

	fmt.Println("- end set user")
	return nil, nil
}

// Query callback representing the query of a chaincode
func (t *systemChaincode) Query(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
	if function != "query" {
		return nil, errors.New("Invalid query function name. Expecting \"query\"")
	}

	if len(args) != 1 {
		return nil, errors.New("Incorrect number of arguments. Expecting 1")
	}

	key := args[0]

	if key != systemValidityPeriodKey {
		return nil, errors.New("Incorrect key. Expecting " + systemValidityPeriodKey)
	}

	// Get the state from the ledger
	vp, err := stub.GetState(key)
	if err != nil {
		jsonResp := "{\"Error\":\"Failed to get state for " + key + "\"}"
		return nil, errors.New(jsonResp)
	}

	if vp == nil {
		jsonResp := "{\"Error\":\"Nil value for " + key + "\"}"
		return nil, errors.New(jsonResp)
	}

	jsonResp := "{\"Name\":\"" + key + "\",\"Value\":\"" + string(vp) + "\"}"
	fmt.Printf("Query Response:%s\n", jsonResp)
	return []byte(jsonResp), nil
}

//==============================================================================================================================
//	 General Functions
//==============================================================================================================================
//	 get_ecert - Takes the name passed and calls out to the REST API for HyperLedger to retrieve the ecert
//				 for that user. Returns the ecert as retrived including html encoding.
//==============================================================================================================================
func (t *SimpleChaincode) get_ecert(stub *shim.ChaincodeStub, name string) ([]byte, error) {

	var cert ECertResponse

	peer_address, err := stub.GetState("Peer_Address")
	if err != nil {
		return nil, errors.New("Error retrieving peer address")
	}

	response, err := http.Get("http://" + string(peer_address) + "/registrar/" + name + "/ecert") // Calls out to the HyperLedger REST API to get the ecert of the user with that name

	if err != nil {
		return nil, errors.New("Error calling ecert API")
	}

	defer response.Body.Close()
	contents, err := ioutil.ReadAll(response.Body) // Read the response from the http callout into the variable contents

	if err != nil {
		return nil, errors.New("Could not read body")
	}

	err = json.Unmarshal(contents, &cert)

	if err != nil {
		return nil, errors.New("Could not retrieve ecert for user: " + name)
	}

	return []byte(string(cert.OK)), nil
}

//==============================================================================================================================
//	Invoke Functions
//==============================================================================================================================
//	add_number - Retrieves the current number value stored in the world state and adds a number passed by the invoker to it
//				and updates Number to the new value in the world state
//==============================================================================================================================
func (t *SimpleChaincode) add_number(stub *shim.ChaincodeStub, args []string) ([]byte, error) {

	//Args
	//				0
	//			Value to add

	adder, _ := strconv.Atoi(args[0])

	bytes, err := stub.GetState("Number")

	if err != nil {
		return nil, errors.New("Unable to get number")
	}

	number, _ := strconv.Atoi(string(bytes))

	newNumber := number + adder

	toPut := strconv.Itoa(newNumber)

	err = stub.PutState("Number", []byte(toPut))

	if err != nil {
		return nil, errors.New("Unable to put the state")
	}

	return nil, nil
}

// ============================================================================================================================
// findMarble4Trade - look for a matching marble that this user owns and return it
// ============================================================================================================================
func findMarble4Trade(stub *shim.ChaincodeStub, user string, color string, size int) (m Marble, err error) {
	var fail Marble
	fmt.Println("- start find marble 4 trade")
	fmt.Println("looking for " + user + ", " + color + ", " + strconv.Itoa(size))

	//get the marble index
	marblesAsBytes, err := stub.GetState(marbleIndexStr)
	if err != nil {
		return fail, errors.New("Failed to get marble index")
	}
	var marbleIndex []string
	json.Unmarshal(marblesAsBytes, &marbleIndex) //un stringify it aka JSON.parse()

	for i := range marbleIndex { //iter through all the marbles
		//fmt.Println("looking @ marble name: " + marbleIndex[i]);

		marbleAsBytes, err := stub.GetState(marbleIndex[i]) //grab this marble
		if err != nil {
			return fail, errors.New("Failed to get marble")
		}
		res := Marble{}
		json.Unmarshal(marbleAsBytes, &res) //un stringify it aka JSON.parse()
		//fmt.Println("looking @ " + res.User + ", " + res.Color + ", " + strconv.Itoa(res.Size));

		//check for user && color && size
		if strings.ToLower(res.User) == strings.ToLower(user) && strings.ToLower(res.Color) == strings.ToLower(color) && res.Size == size {
			fmt.Println("found a marble: " + res.Name)
			fmt.Println("! end find marble 4 trade")
			return res, nil
		}
	}

	fmt.Println("- end find marble 4 trade - error")
	return fail, errors.New("Did not find marble to use in this trade")
}

func (t *SimpleChaincode) get_all_slots(stub *shim.ChaincodeStub, args []string) ([]byte, error) {

	slotsIndexBytes, err := stub.GetState(slotIndexStr)
	if err != nil {
		return nil, errors.New("Failed to get slots index")
	}

	var slotIndex []string
	err = json.Unmarshal(slotsIndexBytes, &slotIndex)
	if err != nil {
		return nil, errors.New("Could not marshal slot indexes")
	}

	var slots []Slot
	for _, slotId := range slotIndex {
		bytes, err := stub.GetState(slotId)
		if err != nil {
			return nil, errors.New("Not able to get slot")
		}

		var s Slot
		err = json.Unmarshal(bytes, &s)
		slots = append(slots, s)
	}

	slotsJson, err := json.Marshal(slots)
	if err != nil {
		return nil, errors.New("Failed to marshal slots to JSON")
	}

	return slotsJson, nil

}

// Query callback representing the query of a chaincode
func (t *SampleSysCC) Query(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
	if function != "getval" {
		return nil, errors.New("Invalid query function name. Expecting \"getval\"")
	}
	var key string // Entities
	var err error

	if len(args) != 1 {
		return nil, errors.New("Incorrect number of arguments. Expecting key to query")
	}

	key = args[0]

	// Get the state from the ledger
	valbytes, err := stub.GetState(key)
	if err != nil {
		jsonResp := "{\"Error\":\"Failed to get state for " + key + "\"}"
		return nil, errors.New(jsonResp)
	}

	if valbytes == nil {
		jsonResp := "{\"Error\":\"Nil val for " + key + "\"}"
		return nil, errors.New(jsonResp)
	}

	return valbytes, nil
}

// Invoke gets the supplied key and if it exists, updates the key with the newly
// supplied value.
func (t *SampleSysCC) Invoke(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
	var key, val string // Entities

	if len(args) != 2 {
		return nil, errors.New("need 2 args (key and a value)")
	}

	// Initialize the chaincode
	key = args[0]
	val = args[1]

	_, err := stub.GetState(key)
	if err != nil {
		jsonResp := "{\"Error\":\"Failed to get val for " + key + "\"}"
		return nil, errors.New(jsonResp)
	}

	// Write the state to the ledger
	err = stub.PutState(key, []byte(val))
	if err != nil {
		return nil, err
	}

	return nil, nil
}

// "create":  true -> create new ID, false -> append the id
func append_id(stub *shim.ChaincodeStub, indexStr string, id string, create bool) ([]byte, error) {

	indexAsBytes, err := stub.GetState(indexStr)
	if err != nil {
		return nil, errors.New("Failed to get " + indexStr)
	}
	fmt.Println(indexStr + " retrieved")

	// Unmarshal the index
	var tmpIndex []string
	json.Unmarshal(indexAsBytes, &tmpIndex)
	fmt.Println(indexStr + " unmarshalled")

	// Create new id
	var newId = id
	if create {
		newId += strconv.Itoa(len(tmpIndex) + 1)
	}

	// append the new id to the index
	tmpIndex = append(tmpIndex, newId)
	jsonAsBytes, _ := json.Marshal(tmpIndex)
	err = stub.PutState(indexStr, jsonAsBytes)
	if err != nil {
		return nil, errors.New("Error storing new " + indexStr + " into ledger")
	}

	return []byte(newId), nil

}

func (t *SimpleChaincode) get_all_devices(stub *shim.ChaincodeStub, args []string) ([]byte, error) {

	devicesIndexBytes, err := stub.GetState(deviceIndexStr)
	if err != nil {
		return nil, errors.New("Failed to get devices index")
	}

	var deviceIndex []string
	err = json.Unmarshal(devicesIndexBytes, &deviceIndex)
	if err != nil {
		return nil, errors.New("Could not marshal device indexes")
	}

	var devices []Device
	for _, deviceId := range deviceIndex {
		bytes, err := stub.GetState(deviceId)
		if err != nil {
			return nil, errors.New("Not able to get device")
		}

		var d Device
		err = json.Unmarshal(bytes, &d)
		devices = append(devices, d)
	}

	devicesJson, err := json.Marshal(devices)
	if err != nil {
		return nil, errors.New("Failed to marshal devices to JSON")
	}

	return devicesJson, nil

}

func (t *SimpleChaincode) get_all_bids(stub *shim.ChaincodeStub, args []string) ([]byte, error) {

	bidIndexBytes, err := stub.GetState(bidIndexStr)
	if err != nil {
		return nil, errors.New("Failed to get bids index")
	}

	var bidIndex []string
	err = json.Unmarshal(bidIndexBytes, &bidIndex)
	if err != nil {
		return nil, errors.New("Could not marshal bid indexes")
	}

	var bids []Bid
	for _, bidId := range bidIndex {
		bytes, err := stub.GetState(bidId)
		if err != nil {
			return nil, errors.New("Not able to get bid")
		}

		var b Bid
		err = json.Unmarshal(bytes, &b)
		bids = append(bids, b)
	}

	bidsJson, err := json.Marshal(bids)
	if err != nil {
		return nil, errors.New("Failed to marshal bids to JSON")
	}

	return bidsJson, nil

}

// ============================================================================================================================
// Delete - remove a key/value pair from state
// ============================================================================================================================
func (t *SimpleChaincode) Delete(stub *shim.ChaincodeStub, args []string) ([]byte, error) {
	if len(args) != 1 {
		return nil, errors.New("Incorrect number of arguments. Expecting 1")
	}

	name := args[0]
	err := stub.DelState(name) //remove the key from chaincode state
	if err != nil {
		return nil, errors.New("Failed to delete state")
	}

	//get the marble index
	marblesAsBytes, err := stub.GetState(marbleIndexStr)
	if err != nil {
		return nil, errors.New("Failed to get marble index")
	}
	var marbleIndex []string
	json.Unmarshal(marblesAsBytes, &marbleIndex) //un stringify it aka JSON.parse()

	//remove marble from index
	for i, val := range marbleIndex {
		fmt.Println(strconv.Itoa(i) + " - looking at " + val + " for " + name)
		if val == name { //find the correct marble
			fmt.Println("found marble")
			marbleIndex = append(marbleIndex[:i], marbleIndex[i+1:]...) //remove it
			for x := range marbleIndex {                                //debug prints...
				fmt.Println(string(x) + " - " + marbleIndex[x])
			}
			break
		}
	}
	jsonAsBytes, _ := json.Marshal(marbleIndex) //save new index
	err = stub.PutState(marbleIndexStr, jsonAsBytes)
	return nil, nil
}

// Query callback representing the query of a chaincode
func (t *SimpleChaincode) Query(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
	if function != "query" {
		return nil, errors.New("Invalid query function name. Expecting \"query\"")
	}
	var A string // Entities
	var err error

	if len(args) != 1 {
		return nil, errors.New("Incorrect number of arguments. Expecting name of the person to query")
	}

	A = args[0]

	// Get the state from the ledger
	Avalbytes, err := stub.GetState(A)
	if err != nil {
		jsonResp := "{\"Error\":\"Failed to get state for " + A + "\"}"
		return nil, errors.New(jsonResp)
	}

	if Avalbytes == nil {
		jsonResp := "{\"Error\":\"Nil amount for " + A + "\"}"
		return nil, errors.New(jsonResp)
	}

	jsonResp := "{\"Name\":\"" + A + "\",\"Amount\":\"" + string(Avalbytes) + "\"}"
	fmt.Printf("Query Response:%s\n", jsonResp)
	return Avalbytes, nil
}

func (t *SampleChaincode) Query(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {

	if len(args) != 1 {
		return nil, errors.New("<name>")
	}

	return stub.GetState(args[0])
}

// Query function
func (t *EventSender) Query(stub *shim.ChaincodeStub, function string, args []string) ([]byte, error) {
	b, err := stub.GetState("noevents")
	if err != nil {
		return nil, errors.New("Failed to get state")
	}
	jsonResp := "{\"NoEvents\":\"" + string(b) + "\"}"
	return []byte(jsonResp), nil
}