スマートコントラクトプログラミング (4) イーサリアム実習 II / Ethereum Practice II

ブロックチェーンハブ主催で開催している (第2期) スマートコントラクトプログラミング講義 (4) 「イーサリアム実習 II」のスライドです。2017年5月31日(水) に使用しました。

Transcript

1. II (4) CSO / SFC ks91@sfc.wide.ad.jp II – (4) – 2017-05-31 – p.1/45
2. 1. : 2. ∼ ∼ II – (4) – 2017-05-31 – p.2/45
3. 1. : 2. : 3. / II – (4) – 2017-05-31 – p.3/45
4. 1. II – (4) – 2017-05-31 – p.4/45
5. (m2 ) 1 1 II – (4) – 2017-05-31 – p.5/45
6. IndivisibleAsset string public _name; string public _symbol; uint256 public _quantity; address public _owner; _name ( ) _symbol _quantity (m2 ) _owner _ Solidity . . . II – (4) – 2017-05-31 – p.6/45
7. IndivisibleAsset event Transfer(address indexed from, address indexed to); from to II – (4) – 2017-05-31 – p.7/45
8. IndivisibleAsset function IndivisibleAsset(string name, string symbol, uint256 quantity) { _name = name; _symbol = symbol; _quantity = quantity; _owner = msg.sender; } II – (4) – 2017-05-31 – p.8/45
9. IndivisibleAsset getOwner() function getOwner() returns (address owner) { return (_owner); } II – (4) – 2017-05-31 – p.9/45
10. IndivisibleAsset transfer() function transfer(address to) { if (_owner != msg.sender) { throw; } _owner = to; Transfer(msg.sender, to); } ( / ) $ populus compile II – (4) – 2017-05-31 – p.10/45
11. (1) import pytest @pytest.fixture() def asset_contract(chain): AssetFactory = chain.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 – (4) – 2017-05-31 – p.11/45
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 – (4) – 2017-05-31 – p.12/45
13. $ py.test tests/test_indivisible_asset.py II – (4) – 2017-05-31 – p.13/45
14. 2. II – (4) – 2017-05-31 – p.14/45
15. transfer settle, retrieve asset, retrieve token 3 II – (4) – 2017-05-31 – p.15/45
16. 1. ( ) 2. ( ) 3. ( ) II – (4) – 2017-05-31 – p.16/45
17. OneTimeEscrow settle() function settle() { address addr = this; /* this */ if (_token.getBalanceOf(this) < _price || _asset.getOwner() != addr) { throw; } _token.transfer(_seller , _price); _asset.transfer(_buyer); Settled(); /* */ } settle() transfer ( / ) $ populus compile II – (4) – 2017-05-31 – p.17/45
18. (1) import pytest @pytest.fixture() def token_contract(chain): . . . @pytest.fixture() def asset_contract(chain): . . . II – (4) – 2017-05-31 – p.18/45
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 – (4) – 2017-05-31 – p.19/45
20. (3) EscrowFactory = chain.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 – (4) – 2017-05-31 – p.20/45
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().getBalanceOf(account0) == 999700 assert token_contract.call().getBalanceOf(account1) == 0 assert token_contract.call().getBalanceOf(contract_address) == 300 assert asset_contract.call().getOwner() == contract_address account1 300BcH account0 II – (4) – 2017-05-31 – p.21/45
22. (5) txid = EscrowFactory.transact().settle(); chain.wait.for_receipt(txid) assert token_contract.call().getBalanceOf(account0) == 1000000 assert token_contract.call().getBalanceOf(account1) == 0 assert token_contract.call().getBalanceOf(contract_address) == 0 assert asset_contract.call().getOwner() == account1 settle() II – (4) – 2017-05-31 – p.22/45
23. $ py.test tests/test_one_time_escrow.py : settle() II – (4) – 2017-05-31 – p.23/45
24. 3. / Hyperledger (Fabric, Sawtooth, Iroha, Burrow) R3 Corda Enterprise Ethereum Alliance II – (4) – 2017-05-31 – p.24/45
25. (Hyperledger ) ( ) ( ) ( ) IoT / / II – (4) – 2017-05-31 – p.25/45
26. ( ) ( ) ← II – (4) – 2017-05-31 – p.26/45
27. (Linux Foundation) https://www.hyperledger.org Apache License, Version 2.0 II – (4) – 2017-05-31 – p.27/45
28. / : Proposal → Incubation → Active → Deprecated → End of Life II – (4) – 2017-05-31 – p.28/45
29. : https://www.hyperledger.org/about/members II – (4) – 2017-05-31 – p.29/45
30. Fabric (IBM) IBM Digital Asset Holdings http://hyperledger-fabric.readthedocs.io/en/latest/ State : Active II – (4) – 2017-05-31 – p.30/45
31. ( ) II – (4) – 2017-05-31 – p.31/45
32. II – (4) – 2017-05-31 – p.32/45
33. (Docker) (chaincode) PBFT (Practical BFT) RocksDB CA PKI v1.0 DB CA II – (4) – 2017-05-31 – p.33/45
34. Sawtooth (Intel) https://github.com/hyperledger/sawtooth-core State : Active II – (4) – 2017-05-31 – p.34/45
35. ( ) (permissioned) (permissionless) Proof of Elapsed Time (PoET) Proof of Work ( ) (Intel ) Transaction Families II – (4) – 2017-05-31 – p.35/45
36. (transaction families) (PoET ) PoET ( ) (transaction families) II – (4) – 2017-05-31 – p.36/45
37. Iroha ( ) https://github.com/hyperledger/iroha State : Active II – (4) – 2017-05-31 – p.37/45
38. ( ) DLT : C++ Sumeragi Whitepaper : https://github.com/hyperledger/iroha/blob/master/docs/iroha_whitepaper.md II – (4) – 2017-05-31 – p.38/45
39. JVM (chaincode) Sumeragi (BFT) II – (4) – 2017-05-31 – p.39/45
40. Corda (R3) R3 https://github.com/corda/corda II – (4) – 2017-05-31 – p.40/45
41. R3 R3CEV 77 (2017 2 ) 3 SBI , R3Net( ) Corda II – (4) – 2017-05-31 – p.41/45
42. Corda Corda : : II – (4) – 2017-05-31 – p.42/45
43. + CAP II – (4) – 2017-05-31 – p.43/45
44. JVM ( ) (Uniqueness Services) UTXO X.509 PKI ( ) II – (4) – 2017-05-31 – p.44/45
45. ⇒ ⇒ II – (4) – 2017-05-31 – p.45/45