chaincode_example02.go

/*
Copyright IBM Corp. 2016 All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

		 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"errors"
	"fmt"
	"strconv"

	"hyperledger/cci/appinit"
	"hyperledger/cci/org/hyperledger/chaincode/example02"
	"hyperledger/ccs"

	"github.com/golang/protobuf/proto"
	"github.com/hyperledger/fabric/core/chaincode/shim"
)

type ChaincodeExample struct {
}

// Called to initialize the chaincode
func (t *ChaincodeExample) Init(stub shim.ChaincodeStubInterface, param *appinit.Init) error {

	var err error

	fmt.Printf("Aval = %d, Bval = %d\n", param.PartyA.Value, param.PartyB.Value)

	// Write the state to the ledger
	err = t.PutState(stub, param.PartyA)
	if err != nil {
		return err
	}

	err = t.PutState(stub, param.PartyB)
	if err != nil {
		return err
	}

	return nil
}

// Transaction makes payment of X units from A to B
func (t *ChaincodeExample) MakePayment(stub shim.ChaincodeStubInterface, param *example02.PaymentParams) error {

	var err error

	// Get the state from the ledger
	src, err := t.GetState(stub, param.PartySrc)
	if err != nil {
		return err
	}

	dst, err := t.GetState(stub, param.PartyDst)
	if err != nil {
		return err
	}

	// Perform the execution
	X := int(param.Amount)
	src = src - X
	dst = dst + X
	fmt.Printf("Aval = %d, Bval = %d\n", src, dst)

	// Write the state back to the ledger
	err = stub.PutState(param.PartySrc, []byte(strconv.Itoa(src)))
	if err != nil {
		return err
	}

	err = stub.PutState(param.PartyDst, []byte(strconv.Itoa(dst)))
	if err != nil {
		return err
	}

	return nil
}

// Deletes an entity from state
func (t *ChaincodeExample) DeleteAccount(stub shim.ChaincodeStubInterface, param *example02.Entity) error {

	// Delete the key from the state in ledger
	err := stub.DelState(param.Id)
	if err != nil {
		return errors.New("Failed to delete state")
	}

	return nil
}

// Query callback representing the query of a chaincode
func (t *ChaincodeExample) CheckBalance(stub shim.ChaincodeStubInterface, param *example02.Entity) (*example02.BalanceResult, error) {
	var err error

	// Get the state from the ledger
	val, err := t.GetState(stub, param.Id)
	if err != nil {
		return nil, err
	}

	fmt.Printf("Query Response: %d\n", val)
	return &example02.BalanceResult{Balance: *proto.Int32(int32(val))}, nil
}

func main() {
	self := &ChaincodeExample{}
	interfaces := ccs.Interfaces{
		"org.hyperledger.chaincode.example02": self,
		"appinit": self,
	}

	err := ccs.Start(interfaces) // Our one instance implements both Transactions and Queries interfaces
	if err != nil {
		fmt.Printf("Error starting example chaincode: %s", err)
	}
}

//-------------------------------------------------
// Helpers
//-------------------------------------------------
func (t *ChaincodeExample) PutState(stub shim.ChaincodeStubInterface, party *appinit.Party) error {
	return stub.PutState(party.Entity, []byte(strconv.Itoa(int(party.Value))))
}

func (t *ChaincodeExample) GetState(stub shim.ChaincodeStubInterface, entity string) (int, error) {
	bytes, err := stub.GetState(entity)
	if err != nil {
		return 0, errors.New("Failed to get state")
	}
	if bytes == nil {
		return 0, errors.New("Entity not found")
	}

	val, _ := strconv.Atoi(string(bytes))
	return val, nil
}