イーサリアム実習 II / Ethereum Practice 2

2018年7月25日(水)、ブロックチェーンハブ主催で開催されたブロックチェーンアカデミー「イーサリアム実習 II」(【ハンズオン】スマートコントラクトプログラミング (3)) にて使用したスライドです。

Transcript

1. II (3) CSO / SFC ( https://speakerdeck.com/ks91 ) ks91@blockchainhub.co.jp II — (3) — 2018-07-25 – p.1/55
2. 1. : ERC20 2. ∼ ∼ II — (3) — 2018-07-25 – p.2/55
3. 1. : 2. : 3. / II — (3) — 2018-07-25 – p.3/55
4. 1. II — (3) — 2018-07-25 – p.4/55
5. (m2 ) 1 1 II — (3) — 2018-07-25 – p.5/55
6. IndivisibleAsset string public _name; string public _symbol; uint256 public _quantity; address public _owner; _name ( ) _symbol _quantity (m2 ) _owner _ Solidity . . . II — (3) — 2018-07-25 – p.6/55
7. IndivisibleAsset event Transfer(address indexed from, address indexed to); from to II — (3) — 2018-07-25 – p.7/55
8. IndivisibleAsset constructor (string name, string symbol, uint256 quantity) public { _name = name; _symbol = symbol; _quantity = quantity; _owner = msg.sender; } II — (3) — 2018-07-25 – p.8/55
9. IndivisibleAsset getOwner() function getOwner() external view returns (address) { return (_owner); } II — (3) — 2018-07-25 – p.9/55
10. IndivisibleAsset transfer() function transfer(address to) external returns (bool) { require(_owner == msg.sender); _owner = to; Transfer(msg.sender, to); return true; } ( / ) $ populus compile II — (3) — 2018-07-25 – p.10/55
11. (1) import pytest @pytest.fixture() def asset_contract(chain): AssetFactory = chain.provider.get_contract_factory(’IndivisibleAsset’) deploy_txid = AssetFactory.deploy(args=[ "5322 Endo, Fujisawa", "mˆ2", 300, ]) contract_address = chain.wait.for_contract_address(deploy_txid) return AssetFactory(address=contract_address) SFC (300m2 ) II — (3) — 2018-07-25 – p.11/55
12. (2) def test_indivisible_assset(asset_contract, chain): account0 = chain.web3.eth.accounts[0] account1 = chain.web3.eth.accounts[1] assert asset_contract.call().getOwner() == account0 txid = asset_contract.transact().transfer(account1) chain.wait.for_receipt(txid) assert asset_contract.call().getOwner() == account1 account0 account1 II — (3) — 2018-07-25 – p.12/55
13. $ py.test -k test_indivisible_asset.py II — (3) — 2018-07-25 – p.13/55
14. 2. II — (3) — 2018-07-25 – p.14/55
15. transfer settle, retrieve asset, retrieve token 3 II — (3) — 2018-07-25 – p.15/55
16. 1. ( ) 2. ( ) 3. ( ) II — (3) — 2018-07-25 – p.16/55
17. OneTimeEscrow settle() function settle() public returns (bool) { require(_token.balanceOf(this) >= _price); /* this */ require(_asset.getOwner() == address(this)); _token.transfer(_seller , _price); _asset.transfer(_buyer); Settled(); /* */ return true; } settle() transfer ( / ) $ populus compile solidity 0.4.21 II — (3) — 2018-07-25 – p.17/55
18. (1) import pytest @pytest.fixture() def token_contract(chain): . . . @pytest.fixture() def asset_contract(chain): . . . II — (3) — 2018-07-25 – p.18/55
19. (2) def test_one_time_escrow(token_contract, asset_contract, chain): account0 = chain.web3.eth.accounts[0] account1 = chain.web3.eth.accounts[1] txid = chain.web3.eth.sendTransaction({ ’from’: account0, ’to’: account1, ’value’: chain.web3.toWei(1, "ether") }) chain.wait.for_receipt(txid) txid = token_contract.transact().transfer(account1, 300) chain.wait.for_receipt(txid) account0 account1 1Ether 300BcH 300BcH TX II — (3) — 2018-07-25 – p.19/55
20. (3) EscrowFactory = chain.provider.get_contract_factory(’OneTimeEscrow’) txid = EscrowFactory.deploy(args=[ token_contract.address, account1, asset_contract.address, account0, 300, ]) contract_address = chain.wait.for_contract_address(txid) EscrowFactory.address = contract_address; account1 account0 300BcH II — (3) — 2018-07-25 – p.20/55
21. (4) txid = token_contract.transact({ ’from’: account1 }).transfer(contract_address, 300) chain.wait.for_receipt(txid) txid = asset_contract.transact().transfer(contract_address) chain.wait.for_receipt(txid) assert token_contract.call().balanceOf(account0) == 999700 assert token_contract.call().balanceOf(account1) == 0 assert token_contract.call().balanceOf(contract_address) == 300 assert asset_contract.call().getOwner() == contract_address account1 300BcH account0 II — (3) — 2018-07-25 – p.21/55
22. (5) txid = EscrowFactory.transact().settle(); chain.wait.for_receipt(txid) assert token_contract.call().balanceOf(account0) == 1000000 assert token_contract.call().balanceOf(account1) == 0 assert token_contract.call().balanceOf(contract_address) == 0 assert asset_contract.call().getOwner() == account1 settle() II — (3) — 2018-07-25 – p.22/55
23. $ py.test -k test_one_time_escrow.py : settle() II — (3) — 2018-07-25 – p.23/55
24. 3. / II — (3) — 2018-07-25 – p.24/55
25. /DLT ਖ਼౰ੑͷอূ ྫ
    
    6590
    ߏ଄ͱσδλϧॺ໊ ଘࡏੑͷূ໌ ྫ
    
    ࡞ۀূ໌෇͖ϋογϡνΣʔϯ །Ұੑͷ߹ҙ ྫ
    
    φΧϞτɾίϯηϯαε ϧʔϧͷهड़ ྫ
    
    #5$
    ͷҠస ɾ
    τϥϯβΫγϣϯͷ಺༰͕վ͟ΜͰ͖ͣɺ ɾ
    ͦͷΞηοτʹؔ͢ΔաڈͷτϥϯβΫγϣϯྻʹরΒͯ͠ໃ६͕ͳ͘ɺ ɾ
    ͔ͭɺਖ਼౰ͳϢʔβʹΑΓ౤ೖ͞Ε͍ͯΔ͜ͱΛอূ͢Δ ɾաڈʹ͋ͬͨτϥϯβΫγϣϯͷূڌΛຣফͰ͖ͣɺ ɾ
    ͔ͭɺաڈʹͳ͔ͬͨτϥϯβΫγϣϯͷূڌΛ፻଄Ͱ͖ͳ͍ ɾໃ६͢Δ;ͨͭͷτϥϯβΫγϣϯ͕౤ೖ͞Εͨ৔߹ɺ ɹ ͍ͣΕ
    ؔ༩͢Δશһ͕ಉ͡ยํΛબΜͰྺ࢙ͷதʹҐஔ͚ͮΔ ɾΞϓϦέʔγϣϯϩδοΫ
    Կ͕ਖ਼͍͠τϥϯβΫγϣϯ͔ΛܾΊΔ II — (3) — 2018-07-25 – p.25/55
26. (Linux Foundation) https://www.hyperledger.org Apache License, Version 2.0 II — (3) — 2018-07-25 – p.26/55
27. / : Proposal → Incubation → Active → Deprecated → End of Life II — (3) — 2018-07-25 – p.27/55
28. ( https://www.hyperledger.org/about/members ) II — (3) — 2018-07-25 – p.28/55
29. Fabric (IBM) IBM Digital Asset Holdings http://hyperledger-fabric.readthedocs.io/en/latest/ State : Active II — (3) — 2018-07-25 – p.29/55
30. ( ) ( ) II — (3) — 2018-07-25 – p.30/55
31. Fabric – (Docker) (chaincode) PBFT (Practical BFT) ( ) RocksDB CA PKI v1.0 DB CA BFT : Byzantine Fault Tolerance ( ) CA : Certificate Authority ( ) PKI : Public Key Infrastructure ( ) II — (3) — 2018-07-25 – p.31/55
32. Sawtooth (Intel) https://github.com/hyperledger/sawtooth-core State : Active II — (3) — 2018-07-25 – p.32/55
33. ( ) (permissioned) (permissionless) Proof of Elapsed Time (PoET) Proof of Work ( ) (Intel ) / Transaction Families II — (3) — 2018-07-25 – p.33/55
34. Sawtooth – (transaction families) (PoET ) PoET ( ) (transaction families) II — (3) — 2018-07-25 – p.34/55
35. Iroha ( ) https://github.com/hyperledger/iroha State : Active II — (3) — 2018-07-25 – p.35/55
36. ( ) DLT : C++ Sumeragi Whitepaper : https://github.com/hyperledger/iroha/blob/master/docs/iroha_whitepaper.md II — (3) — 2018-07-25 – p.36/55
37. Iroha – JVM (chaincode) Sumeragi (BFT) → YAC? JVM : Java Virtual Machine (Java ) II — (3) — 2018-07-25 – p.37/55
38. Corda (R3), Tangle (IOTA), BBc-1 ( ) II — (3) — 2018-07-25 – p.38/55
39. Corda (R3) R3 https://github.com/corda/corda II — (3) — 2018-07-25 – p.39/55
40. R3 R3CEV 77 (2017 2 ) 3 SBI R3Net( ) Corda II — (3) — 2018-07-25 – p.40/55
41. Corda Corda : : II — (3) — 2018-07-25 – p.41/55
42. ( ) + CAP ( DLT ) II — (3) — 2018-07-25 – p.42/55
43. Corda – JVM ( ) (Uniqueness Services) UTXO X.509 PKI ( ) X.509 : PKI II — (3) — 2018-07-25 – p.43/55
44. Tangle (IOTA) IoT IOTA https://iota.readme.io II — (3) — 2018-07-25 – p.44/55
45. IoT TX TX (DAG) ( DAG ) TX Tangle II — (3) — 2018-07-25 – p.45/55
46. Tangle – IoT (IOTA) DAG ( ) DAG II — (3) — 2018-07-25 – p.46/55
47. BBc-1 (Beyond Blockchain One) https://github.com/beyond-blockchain https://beyond-blockchain.org II — (3) — 2018-07-25 – p.47/55
48. Proof of Work Bitcoin ( ) BBc Trust ( ) https://beyond-blockchain.org/public/bbc-trust.pdf ( ) https://beyond-blockchain.org/public/bbc-trust_ja.pdf ( ) Design Paper (white paper) https://beyond-blockchain.org/public/bbc1-design-paper.pdf II — (3) — 2018-07-25 – p.48/55
49. BBc-1 II — (3) — 2018-07-25 – p.49/55
50. BBc-1 – ( Python) ( DAG) ( ) UTXO II — (3) — 2018-07-25 – p.50/55
51. DLT II — (3) — 2018-07-25 – p.51/55
52. ( ) (1) (2) (3) (4) ( ) ⇒ II — (3) — 2018-07-25 – p.52/55
53. ( ) (by ) (since 1984) ( ) ( ) ( ) . . . ( ) ⇒ state machine replication II — (3) — 2018-07-25 – p.53/55
54. ( ) ( ) ( ) ( ) ( ) ( ) (by ) II — (3) — 2018-07-25 – p.54/55
55. BBc-1 1. BBc-1 2. BBc-1 3. 4. Ethereum ( ) II — (3) — 2018-07-25 – p.55/55