forked from IBM-Blockchain-Archive/learn-chaincode
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathchaincode_finished.go
More file actions
257 lines (208 loc) · 6.54 KB
/
chaincode_finished.go
File metadata and controls
257 lines (208 loc) · 6.54 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
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"
"encoding/json"
"strconv"
"github.com/hyperledger/fabric/core/chaincode/shim"
)
// SimpleChaincode example simple Chaincode implementation
type SimpleChaincode struct {
}
func main() {
err := shim.Start(new(SimpleChaincode))
if err != nil {
fmt.Printf("Error starting Simple chaincode: %s", err)
}
}
//structure for account
type Account struct {
Name string `json:"name"`
Balance int `json:"balance"`
}
// Init resets all the things
func (t *SimpleChaincode) Init(stub shim.ChaincodeStubInterface, function string, args []string) ([]byte, error) {
if len(args) != 0 {
return nil, errors.New("No arguments required")
}
var account1, account2, account3 Account
account1.Name = "Vatsala"
account1.Balance = 1000
account2.Name = "Harish"
account2.Balance = 1000
account3.Name = "Narayan"
account3.Balance = 1000
b, err := json.Marshal(account1)
if err != nil {
fmt.Println(err)
return nil, errors.New("Errors while creating json string for account 1")
}
err = stub.PutState("Vatsala", b)
if err != nil {
return nil, err
}
b, err = json.Marshal(account2)
if err != nil {
fmt.Println(err)
return nil, errors.New("Errors while creating json string for account 2")
}
err = stub.PutState("Harish", b)
if err != nil {
return nil, err
}
b, err = json.Marshal(account3)
if err != nil {
fmt.Println(err)
return nil, errors.New("Errors while creating json string for account 3")
}
err = stub.PutState("Narayan", b)
if err != nil {
return nil, err
}
return nil, nil
}
// Invoke isur entry point to invoke a chaincode function
func (t *SimpleChaincode) Invoke(stub shim.ChaincodeStubInterface, function string, args []string) ([]byte, error) {
fmt.Println("invoke is running " + function)
// Handle different functions
if function == "init" {
return t.Init(stub, "init", args)
} else if function == "transfer"{
return t.transfer(stub, args)
}
fmt.Println("invoke did not find func: " + function)
return nil, errors.New("Received unknown function invocation: " + function)
}
// Query is our entry point for queries
func (t *SimpleChaincode) Query(stub shim.ChaincodeStubInterface, function string, args []string) ([]byte, error) {
fmt.Println("query is running " + function)
// Handle different functions
if function == "checkBalance" { //read a variable
return t.checkBalance(stub, args)
}
fmt.Println("query did not find func: " + function)
return nil, errors.New("Received unknown function query: " + function)
}
// write - invoke function to write key/value pair
func (t *SimpleChaincode) write(stub shim.ChaincodeStubInterface, args []string) ([]byte, error) {
var key, value string
var err error
fmt.Println("running write()")
if len(args) != 2 {
return nil, errors.New("Incorrect number of arguments. Expecting 2. name of the key and value to set")
}
key = args[0] //rename for funsies
value = args[1]
err = stub.PutState(key, []byte(value)) //write the variable into the chaincode state
if err != nil {
return nil, err
}
return nil, nil
}
// read - query function to read key/value pair
func (t *SimpleChaincode) read(stub shim.ChaincodeStubInterface, args []string) ([]byte, error) {
var key, jsonResp string
var err error
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting name of the key to query")
}
key = args[0]
valAsbytes, err := stub.GetState(key)
if err != nil {
jsonResp = "{\"Error\":\"Failed to get state for " + key + "\"}"
return nil, errors.New(jsonResp)
}
return valAsbytes, nil
}
//Function to transfer funds from one account to another
func (t *SimpleChaincode) transfer(stub shim.ChaincodeStubInterface, args []string) ([]byte, error) {
var jsonResp string
if len(args) != 3 {
return nil, errors.New("Incorrect number of arguments. Expecting 3")
}
var accFrom Account
var accTo Account
var amount int
accFromAsBytes, err := stub.GetState(args[0])
if err != nil {
jsonResp = "{\"Error\":\"Failed to get state for " + args[0] + "\"}"
return nil, errors.New(jsonResp)
}
err = json.Unmarshal(accFromAsBytes, &accFrom)
if err != nil {
return nil, errors.New("Failed to marshal string to struct of accFrom")
}
accToAsBytes, err := stub.GetState(args[1])
if err != nil {
jsonResp = "{\"Error\":\"Failed to get state for " + args[1] + "\"}"
return nil, errors.New(jsonResp)
}
err = json.Unmarshal(accToAsBytes, &accTo)
if err != nil {
return nil, errors.New("Failed to marshal string to struct of accTo")
}
amount, err = strconv.Atoi(args[2])
if err != nil {
return nil, errors.New("Enter an integer value in the 'Amount'")
}
if accFrom.Balance < amount {
return nil, errors.New("Insufficient Balance")
}
accFrom.Balance = accFrom.Balance - amount
accTo.Balance = accTo.Balance + amount
b, err := json.Marshal(accFrom)
if err != nil {
fmt.Println(err)
return nil, errors.New("Errors while creating json string for account 1")
}
err = stub.PutState(args[0], b)
if err != nil {
return nil, err
}
b, err = json.Marshal(accTo)
if err != nil {
fmt.Println(err)
return nil, errors.New("Errors while creating json string for account 1")
}
err = stub.PutState(args[1], b)
if err != nil {
return nil, err
}
return nil, nil
}
//Function to check balances
func (t *SimpleChaincode) checkBalance(stub shim.ChaincodeStubInterface, args []string) ([]byte, error) {
var jsonResp string
if len(args) != 1 {
return nil, errors.New("Incorrect number of arguments. Expecting 1")
}
var accCurrent Account
var balance int
accCurrentAsBytes, err := stub.GetState(args[0])
if err != nil {
jsonResp = "{\"Error\":\"Failed to get state for " + args[0] + "\"}"
return nil, errors.New(jsonResp)
}
err = json.Unmarshal(accCurrentAsBytes, &accCurrent)
if err != nil {
return nil, errors.New("Failed to marshal string to struct of accCurrent")
}
balance = accCurrent.Balance
balanceAsBytes, err := json.Marshal(balance)
if err != nil {
return nil, errors.New("Failed to marshal balance")
}
return balanceAsBytes, nil
}