github.com/kchristidis/fabric@v1.0.4-0.20171028114726-837acd08cde1/examples/chaincode/go/chaincode_example01/chaincode_example01.go (about) 1 /* 2 Copyright IBM Corp. 2016 All Rights Reserved. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package main 18 19 import ( 20 "fmt" 21 "strconv" 22 23 "github.com/hyperledger/fabric/core/chaincode/shim" 24 pb "github.com/hyperledger/fabric/protos/peer" 25 ) 26 27 // SimpleChaincode example simple Chaincode implementation 28 type SimpleChaincode struct { 29 } 30 31 var A, B string 32 var Aval, Bval, X int 33 34 // Init callback representing the invocation of a chaincode 35 // This chaincode will manage two accounts A and B and will transfer X units from A to B upon invoke 36 func (t *SimpleChaincode) Init(stub shim.ChaincodeStubInterface) pb.Response { 37 var err error 38 _, args := stub.GetFunctionAndParameters() 39 if len(args) != 4 { 40 return shim.Error("Incorrect number of arguments. Expecting 4") 41 } 42 43 // Initialize the chaincode 44 A = args[0] 45 Aval, err = strconv.Atoi(args[1]) 46 if err != nil { 47 return shim.Error("Expecting integer value for asset holding") 48 } 49 B = args[2] 50 Bval, err = strconv.Atoi(args[3]) 51 if err != nil { 52 return shim.Error("Expecting integer value for asset holding") 53 } 54 fmt.Printf("Aval = %d, Bval = %d\n", Aval, Bval) 55 56 /************ 57 // Write the state to the ledger 58 err = stub.PutState(A, []byte(strconv.Itoa(Aval)) 59 if err != nil { 60 return nil, err 61 } 62 63 stub.PutState(B, []byte(strconv.Itoa(Bval)) 64 err = stub.PutState(B, []byte(strconv.Itoa(Bval)) 65 if err != nil { 66 return nil, err 67 } 68 ************/ 69 return shim.Success(nil) 70 } 71 72 func (t *SimpleChaincode) invoke(stub shim.ChaincodeStubInterface, args []string) pb.Response { 73 // Transaction makes payment of X units from A to B 74 X, err := strconv.Atoi(args[0]) 75 if err != nil { 76 fmt.Printf("Error convert %s to integer: %s", args[0], err) 77 return shim.Error(fmt.Sprintf("Error convert %s to integer: %s", args[0], err)) 78 } 79 Aval = Aval - X 80 Bval = Bval + X 81 ts, err2 := stub.GetTxTimestamp() 82 if err2 != nil { 83 fmt.Printf("Error getting transaction timestamp: %s", err2) 84 return shim.Error(fmt.Sprintf("Error getting transaction timestamp: %s", err2)) 85 } 86 fmt.Printf("Transaction Time: %v,Aval = %d, Bval = %d\n", ts, Aval, Bval) 87 return shim.Success(nil) 88 } 89 90 func (t *SimpleChaincode) Invoke(stub shim.ChaincodeStubInterface) pb.Response { 91 function, args := stub.GetFunctionAndParameters() 92 if function == "invoke" { 93 return t.invoke(stub, args) 94 } 95 96 return shim.Error("Invalid invoke function name. Expecting \"invoke\"") 97 } 98 99 func main() { 100 err := shim.Start(new(SimpleChaincode)) 101 if err != nil { 102 fmt.Printf("Error starting Simple chaincode: %s", err) 103 } 104 }