Coverage Summary for Class: BN128PrecompiledContract (co.rsk.pcc.altBN128)
Class |
Class, %
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Method, %
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Line, %
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BN128PrecompiledContract |
0%
(0/1)
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0%
(0/4)
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0%
(0/19)
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1 /*
2 * This file is part of RskJ
3 * Copyright (C) 2021 RSK Labs Ltd.
4 *
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18
19 package co.rsk.pcc.altBN128;
20
21 import co.rsk.pcc.altBN128.impls.AbstractAltBN128;
22 import org.ethereum.config.blockchain.upgrades.ActivationConfig;
23 import org.ethereum.config.blockchain.upgrades.ConsensusRule;
24 import org.ethereum.vm.PrecompiledContracts;
25 import org.ethereum.vm.exception.VMException;
26
27 import static org.ethereum.util.ByteUtil.EMPTY_BYTE_ARRAY;
28
29 /**
30 * @author Patricio Gallardo
31 * @since 07.01.2021
32 */
33 public abstract class BN128PrecompiledContract extends PrecompiledContracts.PrecompiledContract {
34
35 private final ActivationConfig.ForBlock activations;
36 protected final AbstractAltBN128 altBN128Lib;
37
38 public BN128PrecompiledContract(ActivationConfig.ForBlock activations, AbstractAltBN128 altBN128) {
39 this.activations = activations;
40 this.altBN128Lib = altBN128;
41 }
42
43 /**
44 * This is a Template Method, subclasses should override 'concreteExecute()' method.
45 */
46 @Override
47 public byte[] execute(byte[] data) throws VMException {
48 if (activations.isActive(ConsensusRule.RSKIP197)) {
49 return unsafeExecute(data);
50 } else {
51 return safeExecute(data);
52 }
53 }
54
55 /**
56 * After RSKIP197 we can throw exception of {@link VMException} and they will properly handled as an error.
57 */
58 private byte[] unsafeExecute(byte[] data) throws VMException {
59 if (data == null) {
60 data = EMPTY_BYTE_ARRAY;
61 }
62 int rs = concreteExecute(data);
63 if (rs < 0) {
64 throw new VMException("Invalid result.");
65 }
66 return altBN128Lib.getOutput();
67 }
68
69 /**
70 * Before RSKIP197 there were no way of throwing an error, so it returned an empty byte array.
71 */
72 private byte[] safeExecute(byte[] data) {
73 if (data == null) {
74 data = EMPTY_BYTE_ARRAY;
75 }
76 int rs = concreteExecute(data);
77 if (rs < 0) {
78 return EMPTY_BYTE_ARRAY;
79 }
80 return altBN128Lib.getOutput();
81 }
82
83 protected abstract int concreteExecute(byte[] data);
84 }