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 Exercise II, Smart Contract Programming 4

ブロックチェーンハブ主催で開催しているブロックチェーン連続講義シリーズ「スマートコントラクトプログラミング」の第4回「イーサリアム実習 II」のスライドです。2016年10月28日(金) に使用しました。

Transcript

1. II (4) SFC / CSO ks91@sfc.wide.ad.jp I — (4) – 2016-10-28 – p.1/51
2. 1. : 2. ∼ ∼ I — (4) – 2016-10-28 – p.2/51
3. 1. : 2. : 3. / I — (4) – 2016-10-28 – p.3/51
4. 1. : I — (4) – 2016-10-28 – p.4/51
5. ( ) $ geth --networkid 12345678 --port 50303 --maxpeers 0 --nodiscover console 2>> node.log > > exit $ tail -f node.log (Mac OS X, Linux) > Get-Content node.log -Wait -Tail 10 (Windows PowerShell) I — (4) – 2016-10-28 – p.5/51
6. ( ) geth > miner.start(2) true ‘2’ ( CPU ) > miner.stop() I — (4) – 2016-10-28 – p.6/51
7. Ethereum-Wallet “LAUNCH APPLICATION” I — (4) – 2016-10-28 – p.7/51
8. (m2 ) 1 1 I — (4) – 2016-10-28 – p.8/51
9. IndivisibleAsset string public _name; string public _symbol; uint256 public _quantity; address public _owner; _name ( ) _symbol _quantity (m2 ) _owner _ Solidity . . . I — (4) – 2016-10-28 – p.9/51
10. IndivisibleAsset event Transfer(address indexed from, address indexed to); from to I — (4) – 2016-10-28 – p.10/51
11. IndivisibleAsset function IndivisibleAsset(string name, string symbol, uint256 quantity) { _name = name; _symbol = symbol; _quantity = quantity; _owner = msg.sender; } I — (4) – 2016-10-28 – p.11/51
12. IndivisibleAsset transfer() function transfer(address to) { if (_owner != msg.sender) { throw; } _owner = to; Transfer(msg.sender, to); } I — (4) – 2016-10-28 – p.12/51
13. ( pragma solidity ˆ0.4.2; ) (300m2 ) I — (4) – 2016-10-28 – p.13/51
14. I — (4) – 2016-10-28 – p.14/51
15. (1) I — (4) – 2016-10-28 – p.15/51
16. (2) select function Transfer To EXECUTE TX I — (4) – 2016-10-28 – p.16/51
17. (3) _owner I — (4) – 2016-10-28 – p.17/51
18. (4) . . . throw gas I — (4) – 2016-10-28 – p.18/51
19. (5) I — (4) – 2016-10-28 – p.19/51
20. (6) To Execute from I — (4) – 2016-10-28 – p.20/51
21. (7) I — (4) – 2016-10-28 – p.21/51
22. 2. : I — (4) – 2016-10-28 – p.22/51
23. transfer settle, retrieve asset, retrieve token 3 I — (4) – 2016-10-28 – p.23/51
24. 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 I — (4) – 2016-10-28 – p.24/51
25. (1) 1. http://goo.gl/2ICiuu OneTimeEscrow.sol MyToken, IndivisibleAsset OneTimeEscrow 2. ( ) 3. MyToken (BcH Coin, BcH, decimals = 2) 4. IndivisibleAsset (5322 Endo, Fujisawa, 300 m2) 5. Account 2 300.00 BcH I — (4) – 2016-10-28 – p.25/51
26. (2) 1. BcH Coin 2. 5322 Endo, Fujisawa 3. 4. Account 2 I — (4) – 2016-10-28 – p.26/51
27. Token : BcH Coin Buyer : Account 2 Asset : 5322 Endo, Fujisawa Seller : Price : 30000 (300.00 ) I — (4) – 2016-10-28 – p.27/51
28. (1) Account 2 300.00 BcH I — (4) – 2016-10-28 – p.28/51
29. (2) 300.00 BcH I — (4) – 2016-10-28 – p.29/51
30. (1) 5322 Endo, Fujisawa I — (4) – 2016-10-28 – p.30/51
31. (2) 5322 Endo, Fujisawa I — (4) – 2016-10-28 – p.31/51
32. (1) Select function Settle Execute from Account 2 I — (4) – 2016-10-28 – p.32/51
33. (2) 300.00 BcH I — (4) – 2016-10-28 – p.33/51
34. (3) Account 2 5322 Endo, Fujisawa I — (4) – 2016-10-28 – p.34/51
35. (4) Settled I — (4) – 2016-10-28 – p.35/51
36. 3. / Hyperledger (Fabric) Chain Open Standard R3 Corda I — (4) – 2016-10-28 – p.36/51
37. (Hyperledger ) ( ) ( ) ( ) IoT / / I — (4) – 2016-10-28 – p.37/51
38. (Chain OS ) : USD ( ) USD 1 ( ) : 1EUR 1.13USD 0.79GBP 10,000EUR USD I — (4) – 2016-10-28 – p.38/51
39. ( ) ( ) I — (4) – 2016-10-28 – p.39/51
40. Hyperledger https://www.hyperledger.org Fabric : IBM DAH Sawtooth Lake : Intel Iroha : Hyperledger Whitepaper (WG page) I — (4) – 2016-10-28 – p.40/51
41. / I — (4) – 2016-10-28 – p.41/51
42. (Fabric) (from Hyperledger Whitepaper) I — (4) – 2016-10-28 – p.42/51
43. Chain Open Standard http://chain.com/os/ Nasdaq Linq → → → I — (4) – 2016-10-28 – p.43/51
44. I — (4) – 2016-10-28 – p.44/51
45. (Chain Core) HTTP+JSON API, RPC , I — (4) – 2016-10-28 – p.45/51
46. UTXO SBFT : Simplified Byzantine Fault Tolerance BFT I — (4) – 2016-10-28 – p.46/51
47. R3 Corda Introducing R3 CordaTM: A Distributed Ledger Designed for Financial Services http://r3cev.com/s/corda-introductory-whitepaper-final.pdf I — (4) – 2016-10-28 – p.47/51
48. Corda : : I — (4) – 2016-10-28 – p.48/51
49. + CAP I — (4) – 2016-10-28 – p.49/51
50. ⇒ ⇒ I — (4) – 2016-10-28 – p.50/51
51. 2016 12 6 ( ) 18:30-20:00 @ 20:00-20:30 ( ) : 30 : I — (4) – 2016-10-28 – p.51/51