198 uint amountSentUsd = tenantPayment.mul(ETHUSD).div(1e18);
139
243 landlordAddress.transfer(leaseDeposit.div(ETHUSD).mul(1e18));
270 leaseDeposit
22}
14 uint leaseBalanceWei;
55
199
29 uint16 monthlyAmountUsd;
186 require(!lease.leaseFullyPaid, “Lease has already been fully paid”);
15 uint8,
158 tenantPayment = msg.value;
6
245 emit leaseDepositCollected(
140 emit leaseCreated(
227 function collectLeaseDeposit(address payable tenantAddr) public onlyLandlord {
62 address tenantAddress,
最后，第45行是回退函数。假如智能合约随机吸收（也许是从房东哪里吸收的以太坊）以增补可证明的查询，它会优雅地收到以太坊，并将其添加到余额中。
268 emit leaseDepositReclaimed(
13 Lease storage lease = tenantLease[tenantAddress];
20 leaseDeposit
8 transferAmount,
45function() external payable {}
46 event leaseCreated(
第41–43行声明白另一个实用措施成果，以显示智能合约的当前余额。为了得到余额，我们必需将this（智能合约实例）转换为address范例，然后从中读取balance。
43}
254 require(lease.leaseDepositUsd > 0, “Lease deposit has already been removed”);
206 leaseBalanceWei = leaseBalanceWei.add(tenantPayment);
94 require(provable_getPrice(“URL”) < address(this).balance, “Not enough Ether in contract, please add more”);
142 0,
28 lease.leaseDepositUsd,
145 leasePaymentWindowSeconds,
75
202 “Lease payment must be greater than or equal to the monthly amount with a maximum offset of $5”);
106 _payLeaseDeposit();
30 uint16 leaseDepositUsd;
157 tenantAddress = msg.sender;
第37–39行是一个实用函数，用于检索当前的ETHUSD汇率。
162
19 uint64,
29 lease.leasePaymentWindowSeconds,
7 workingState = State.reclaimingLeaseDeposit;
159 workingState = State.payingLeaseDeposit;
51 uint32 leasePaymentWindowSeconds,
15 lease.leaseDepositUsd = 0;
152 function payLeaseDeposit() public payable {
174 lease.depositPaymentWindowEnd = 0;
101 require(msg.sender == provable_cbAddress(), “Calling address does match usingProvable contract address “);
123 ) public onlyLandlord {
第2行确保余额大于0。
130 monthlyAmountUsd,
36 }
57 address tenantAddress,
39 mapping (address => Lease) tenantLease;
135 false,
32 lease.leaseDepositPaid,
2 require(leaseBalanceWei > 0, “Lease balance must be greater than 0”);
28 uint8 monthsPaid;
182
22 }
68 uint amountCollected
175 lease.leasePaymentWindowEnd = uint64(now + lease.leasePaymentWindowSeconds);
第2-4行是反复逻辑。
216 );
82 event fundsWithdrawn(
34 bool leaseDepositPaid;
1function withdrawFunds() public onlyLandlord {
76 event leaseFullyPaid(
102 validIds[myId] = false;
283 );
215 monthsPaid
1pragma solidity ^0.5.17;
95 bytes32 queryId = provable_query(“URL”, “json(https://api.pro.coinbase.com/products/ETH-USD/ticker).price”);
42 return uint(address(this).balance);
53 bool leaseFullyPaid
60
10 address payable tenantAddress;
16 uint16,
143 monthlyAmountUsd,
37function getRate() public view returns (uint) {
43 _;
61 event leasePaymentPaid(
275 require(leaseBalanceWei > 0, “Lease balance must be greater than 0”);
56 event leaseDepositPaid(
278 landlordAddress.transfer(transferAmount);
10 );
112 _reclaimLeaseDeposit();
197 Lease storage lease = tenantLease[tenantAddress];
153 Lease storage lease = tenantLease[msg.sender];
以下是完整的智能合约代码：
260
128 numberOfMonths,
70
67 address tenantAddress,
183 function payLease() public payable {
113 }
23
88 landlordAddress = msg.sender;
277 leaseBalanceWei = 0;
19 tenantAddress,
32 uint64 leasePaymentWindowEnd;
11}
244
35 bool leaseFullyPaid;
84 uint leaseBalanceWei
23 Lease memory lease = tenantLease[tenant];
第3-5行显示了与_collectLeaseDeposit和_reclaimLeaseDeposit沟通的提款方法。智能合约将余额转移给房东。
81
190 tenantPayment = msg.value;
249 }
11
276 uint transferAmount = leaseBalanceWei;
170 amountSentUsd <= lease.leaseDepositUsd + 5,
34 );
154 require(!lease.leaseDepositPaid, “Lease deposit is already paid.”);
192 fetchUsdRate();
230 require(lease.leasePaymentWindowEnd <= now, “Lease payment must be overdue past payment window to collect lease deposit”);
118 uint16 monthlyAmountUsd,
200 require(
205 lease.monthsPaid = uint8(monthsPaid);
163 function _payLeaseDeposit() internal {
272 }
126
114 }
111 } else if (workingState == State.reclaimingLeaseDeposit) {
31 lease.depositPaymentWindowEnd,
238 function _collectLeaseDeposit() internal {
189 tenantAddress = msg.sender;
194
第24–34行汇报函数返回Lease工具上的所有属性。
236 }
136 false,
18 emit leaseDepositReclaimed(
第7-10行发出了fundsWithdrawn事件。
12 uint ETHUSD;
87 constructor () public payable {
42 require(msg.sender == landlordAddress, “Must be the landlord to create a lease”);
234 workingState = State.collectingLeaseDeposit;
218 lease.leasePaymentWindowEnd = lease.leasePaymentWindowEnd + lease.leasePaymentWindowSeconds;
115
137 false
83 uint transferAmount,
37
20 uint64,
41function getContractBalance() public view returns (uint) {
184 Lease storage lease = tenantLease[msg.sender];
38 return ETHUSD;
16 tenantAddress.transfer(leaseDeposit.div(ETHUSD).mul(1e18));
107 } else if (workingState == State.payingLease) {
286 function getLease(address tenant) public view returns (
226
264 uint leaseDeposit = lease.leaseDepositUsd;
9 leaseBalanceWei
13function getLease(address tenant) public view returns (
221 tenantAddress,
214 lease.numberOfMonths,
25 lease.numberOfMonths,
151
237
4 leaseBalanceWei = 0;
第13–35行暗示一个实用函数，用于在给定租户地点的环境下检索激活Lease上的所有属性。
187 require(lease.leasePaymentWindowEnd >= now, “Lease payment must fit into payment window”);
220 emit leasePaymentPaid(
267
104
100 require(validIds[myId], “Provable query IDs do not match, no valid call was made to provable_query()”);
21 idle
9}
15
172
134 depositPaymentWindowEnd,
1function reclaimLeaseDeposit() public {
213 tenantAddress,
49 uint16 monthlyAmountUsd,
74 );
36
247 leaseDeposit
168 require(
5contract LeaseGenerator is usingProvable {
3 require(lease.leaseFullyPaid, “Lease must be fully paid to take back lease deposit”);
52 bool leaseDepositPaid,
44
47 uint8 numberOfMonths,
191 workingState = State.payingLease;
124
285
204 uint monthsPaid = uint256(lease.monthsPaid).add(amountSentUsd.add(10).div(uint256(lease.monthlyAmountUsd)));
188
14 uint8,
177 emit leaseDepositPaid(
288 uint8,
3 uint transferAmount = leaseBalanceWei;
287 uint8,
8
38 mapping (bytes32 => bool) validIds;
229 require(!lease.leaseFullyPaid, “Cannot collect lease deposit if lease is already paid”);
22 bool) {
6 tenantAddress = msg.sender;
148 false
69 );
30 lease.leasePaymentWindowEnd,
219
33 lease.leaseFullyPaid
149 );
3import “./provableAPI.sol”;
185 require(lease.leaseDepositPaid, “Lease deposit must be paid before making lease payments”);
105 if (workingState == State.payingLeaseDeposit) {
73 uint amountReclaimed
第1行例示了我们的public函数，用于收回租赁押金。租户已全额付清租金，这函数由租户挪用。
40
71 event leaseDepositReclaimed(
231 require(lease.leaseDepositUsd > 0, “Lease deposit has already been removed”);
116 function createNewLease(
169 amountSentUsd >= lease.leaseDepositUsd – 5 &&
91 }
44 }
203
21 bool,
193 }
21 );
24 State workingState;
127 tenantLease[tenantAddr] = Lease(
40
256 tenantAddress = msg.sender;
258 fetchUsdRate();
262 workingState = State.idle;
72 address tenantAddress,
31 uint32 leasePaymentWindowSeconds;
92
20 reclaimingLeaseDeposit,
25
19 collectingLeaseDeposit,
85 );
18 payingLease,
144 leaseDepositUsd,
160 fetchUsdRate();
99 function __callback(bytes32 myId, string memory result) public {
171 “Deposit payment must equal to the deposit amount with a maximum offset of $5”);
5
195 function _payLease() internal {
13 uint tenantPayment;
129 0,
77 address tenantAddress,
240 Lease storage lease = tenantLease[tenantAddress];
150 }
209 lease.leaseFullyPaid = true;
109 } else if (workingState == State.collectingLeaseDeposit) {
125 uint64 depositPaymentWindowEnd = uint64(now.add(depositPaymentWindowSeconds));
103 ETHUSD = parseInt(result);
251 function reclaimLeaseDeposit() public {
252 Lease storage lease = tenantLease[msg.sender];
225 }
271 );
164 workingState = State.idle;
281 transferAmount,
108 _payLease();
133 0,
35}
8 fetchUsdRate();
235 fetchUsdRate();
266 tenantAddress.transfer(leaseDeposit.div(ETHUSD).mul(1e18));
10
45
11function _reclaimLeaseDeposit() internal {
97 }
17 payingLeaseDeposit,
93 function fetchUsdRate() internal {
第11行开始internal函数，以继承收回租赁押金的进程。此函数的其余部门是collectLeaseDeposit的反复逻辑。
217 } else {
284 }
4 require(lease.leaseDepositUsd > 0, “Lease deposit has already been removed”);
14 uint leaseDeposit = lease.leaseDepositUsd;
173 lease.leaseDepositPaid = true;
17
78 uint numberOfmonths,
5 landlordAddress.transfer(transferAmount);
156
166 uint amountSentUsd = tenantPayment.mul(ETHUSD).div(1e18);
第23行提出了有问题的Lease并将其分派给memory。不必预先为它筹备storage，只需要读取它即可。
54 );
24 return (
86
120 uint32 leasePaymentWindowSeconds,
196 workingState = State.idle;
12
9 address payable landlordAddress;
259 }
65
64 );
280 emit fundsWithdrawn(
165 Lease storage lease = tenantLease[tenantAddress];
121 uint32 depositPaymentWindowSeconds,
27 uint8 numberOfMonths;
269 tenantAddress,
228 Lease storage lease = tenantLease[tenantAddr];
89 provable_setCustomGasPrice(100000000000);
27 lease.monthlyAmountUsd,
66 event leaseDepositCollected(
第6-8行是反复逻辑。
17 uint16,
第1-11行是房东挪用的用于提取租赁付款的函数。
208 if (monthsPaid == lease.numberOfMonths) {
233 tenantAddress = tenantAddr;
257 workingState = State.reclaimingLeaseDeposit;
232
132 leasePaymentWindowSeconds,
176
33 uint64 depositPaymentWindowEnd;
138 );
239 workingState = State.idle;
161 }
39}
274 function withdrawFunds() public onlyLandlord {
41 modifier onlyLandlord() {
2import “./SafeMath.sol”;
265 lease.leaseDepositUsd = 0;
179 amountSentUsd
147 false,
131 leaseDepositUsd,
180 );
119 uint16 leaseDepositUsd,
155 require(lease.depositPaymentWindowEnd >= now, “Lease deposit payment must fit into payment window”);
16 enum State {
178 tenantAddress,
224 }
212 emit leaseFullyPaid(
80 );
12 workingState = State.idle;
4
18 uint32,
141 numberOfMonths,
58 uint amountSentUsd
167
181 }
248 );
273
253 require(lease.leaseFullyPaid, “Lease must be fully paid to take back lease deposit”);
26 lease.monthsPaid,
122 address payable tenantAddr
90 OAR = OracleAddrResolverI(0xB7D2d92e74447535088A32AD65d459E97f692222);
第13-22行汇报函数它必需返回哪些范例。
279
242 lease.leaseDepositUsd = 0;
207
117 uint8 numberOfMonths,
110 _collectLeaseDeposit();
255
2 Lease storage lease = tenantLease[msg.sender];
7 emit fundsWithdrawn(
246 tenantAddress,
98
211
201 amountSentUsd >= lease.monthlyAmountUsd – 5,
63 uint amountSentUsd
26 struct Lease {
282 leaseBalanceWei
146 false,
48 uint8 monthsPaid,
50 uint16 leaseDepositUsd,
222 amountSentUsd
59 );
241 uint leaseDeposit = lease.leaseDepositUsd;
79 uint monthsPaid
250
210 lease.leasePaymentWindowEnd = 0;
223 );
6
96 validIds[queryId] = true;
263 Lease storage lease = tenantLease[tenantAddress];
，
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