Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
BBc-1 と Ethereum 演習 II / BBc-1 and Ethereum Pra...
Search
Kenji Saito
PRO
October 20, 2021
Technology
0
110
BBc-1 と Ethereum 演習 II / BBc-1 and Ethereum Practice II
2021年10月20日(水)、ブロックチェーンハブ主催のブロックチェーンアカデミー「BBc-1 と Ethereum 演習 II」にて使用したスライドです。
Kenji Saito
PRO
October 20, 2021
Tweet
Share
More Decks by Kenji Saito
See All by Kenji Saito
スマートコントラクトプログラミング / Smart Contract Programming
ks91
PRO
0
4
AI が研究する時代に、人はどう育つのか? — GAMER PAT にみる "シリアスゲームとしての知的訓練" / In an era where AI conducts research, how will humans develop? — "Intellectual Training as a Serious Game" Seen in GAMER PAT
ks91
PRO
0
36
FinTech 5-6 : The World of Apps
ks91
PRO
0
67
生成AI による論文執筆サポート・ワークショップ ─ サーベイ/リサーチクエスチョン編 / Workshop on AI-Assisted Paper Writing Support: Survey/Research Question Edition
ks91
PRO
0
66
ブロックチェーン概論とインストール大会 / Introduction to Blockchain and Installation Workshop
ks91
PRO
0
2
FinTech 3-4 : Internet Technology and Governance
ks91
PRO
0
71
民主主義と博愛(Humanitarianism) / Democracy and Humanitarianism
ks91
PRO
0
6
ブロックチェーン概論 / Introduction to Blockchain
ks91
PRO
0
12
ブロックチェーンと分散ファイナンス概論 / Introduction to Blockchain and Decentralized Finance
ks91
PRO
0
65
Other Decks in Technology
See All in Technology
Simplifying Cloud Native app testing across environments with Dapr and Microcks
salaboy
0
160
能登半島地震で見えた災害対応の課題と組織変革の重要性
ditccsugii
0
930
OAuthからOIDCへ ― 認可の仕組みが認証に拡張されるまで
yamatai1212
0
120
[Codex Meetup Japan #1] Codex-Powered Mobile Apps Development
korodroid
2
790
Findy Team+ QAチーム これからのチャレンジ!
findy_eventslides
0
190
【Kaigi on Rails 事後勉強会LT】MeはどうしてGirlsに? 私とRubyを繋いだRail(s)
joyfrommasara
0
260
大規模サーバーレスAPIの堅牢性・信頼性設計 〜AWSのベストプラクティスから始まる現実的制約との向き合い方〜
maimyyym
9
4.7k
Bill One 開発エンジニア 紹介資料
sansan33
PRO
4
14k
やる気のない自分との向き合い方/How to Deal with Your Unmotivated Self
sanogemaru
0
500
Geospatialの世界最前線を探る [2025年版]
dayjournal
1
220
ユーザーの声とAI検証で進める、プロダクトディスカバリー
sansantech
PRO
1
140
BI ツールはもういらない?Amazon RedShift & MCP Server で試みる新しいデータ分析アプローチ
cdataj
0
160
Featured
See All Featured
Unsuck your backbone
ammeep
671
58k
The World Runs on Bad Software
bkeepers
PRO
72
11k
Building Flexible Design Systems
yeseniaperezcruz
329
39k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
234
17k
Producing Creativity
orderedlist
PRO
347
40k
For a Future-Friendly Web
brad_frost
180
9.9k
A designer walks into a library…
pauljervisheath
209
24k
Java REST API Framework Comparison - PWX 2021
mraible
34
8.9k
Speed Design
sergeychernyshev
32
1.2k
How STYLIGHT went responsive
nonsquared
100
5.8k
Building Better People: How to give real-time feedback that sticks.
wjessup
369
20k
Site-Speed That Sticks
csswizardry
12
900
Transcript
3 BBc-1 Ethereum II CSO /
[email protected]
— 3 BBc-1
Ethereum II — 2021-10-20 – p.1/37
https://speakerdeck.com/ks91 — 3 BBc-1 Ethereum II — 2021-10-20 – p.2/37
( ) SFC ( ) CSO (Chief Science Officer) 1993
( ) 2006 ( ) SFC 21 P2P (Peer-to-Peer) 2011 2018 2019 VR 2021.7 , VR 2021.8 “ALL THESE WORLDS ARE YOURS”, VR 2021.9 & ( (VR) ) → ( ) — 3 BBc-1 Ethereum II — 2021-10-20 – p.3/37
BBc-1 Ethereum 3 Ethereum — 3 BBc-1 Ethereum II —
2021-10-20 – p.4/37
1. : ERC20 2. : 3. : — 3 BBc-1
Ethereum II — 2021-10-20 – p.5/37
1. : ERC20 $ brownie bake token — 3 BBc-1
Ethereum II — 2021-10-20 – p.6/37
Solidity JavaScript ( , ) (constructor) ( ) ( )
Ether Ethereum — 3 BBc-1 Ethereum II — 2021-10-20 – p.7/37
pragma solidity ˆ0.6.0; /* 0.8.x */ contract Token { (
) : (EVM ) : constructor (...) public { /* */ : } function balanceOf(...) { /* ( ) */ : } : } constructor C (/* */ // ) — 3 BBc-1 Ethereum II — 2021-10-20 – p.8/37
ERC20 ERC (Ethereum Request for Comment) 20 https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md contract ERC20
{ function totalSupply() constant returns (uint totalSupply); function balanceOf(address _owner) constant returns (uint balance); function transfer(address _to, uint _value) returns (bool success); function transferFrom(address _from, address _to, uint _value) returns (bool success); function approve(address _spender, uint _value) returns (bool success); function allowance(address _owner, address _spender) constant returns (uint remaining); event Transfer(address indexed _from, address indexed _to, uint _value); event Approval(address indexed _owner, address indexed _spender, uint _value); } name/ , symbol/ , decimals/ approve allowance ERC223 ( ), ERC721 (Non-Fungible) — 3 BBc-1 Ethereum II — 2021-10-20 – p.9/37
ERC20 ERC20 ( ) ⇒ ERC20 ( ERC20 ) ERC20
⇒ — 3 BBc-1 Ethereum II — 2021-10-20 – p.10/37
(fungible) ERC20 → ERC223 (draft) or ERC777 (non-fungible) ERC721 (
) (partially fungible) ERC1410 (draft) (ERC1400 ) — 3 BBc-1 Ethereum II — 2021-10-20 – p.11/37
Token ( ) string public symbol; string public name; uint256
public decimals; uint256 public totalSupply; mapping(address => uint256) balances; . . . name, symbol decimals : 2 100 1.00 mapping balances — 3 BBc-1 Ethereum II — 2021-10-20 – p.12/37
Token ( ) event Transfer(address from, address to, uint256 value);
Token function emit Transfer() ( ) — 3 BBc-1 Ethereum II — 2021-10-20 – p.13/37
Token ( ) constructor( string memory _symbol, string memory _name,
uint256 _decimals, uint256 _totalSupply ) public { symbol = _symbol; name = _name; decimals = _decimals; totalSupply = _totalSupply; balances[msg.sender] = _totalSupply; } msg.sender _totalSupply — 3 BBc-1 Ethereum II — 2021-10-20 – p.14/37
Token balanceOf() function balanceOf(address _owner) public view returns (uint256) {
return balances[_owner]; } — 3 BBc-1 Ethereum II — 2021-10-20 – p.15/37
Token transfer() function transfer(address _to, uint256 _value) public returns (bool)
{ balances[msg.sender] = balances[msg.sender].sub(_value); balances[_to] = balances[_to].add(_value); emit Transfer(msg.sender, _to, _value); return true; } ( ↑ ) OpenZeppelin https://openzeppelin.org — 3 BBc-1 Ethereum II — 2021-10-20 – p.16/37
2. — 3 BBc-1 Ethereum II — 2021-10-20 – p.17/37
GitHub git clone $ git clone https://github.com/ks91/sample-smart-contracts.git sample-smart-contracts contracts, scripts
tests token Token Solidity 0.5 0.6/0.7 (Token ) Token Solidity 0.5 0.6 Solidity — 3 BBc-1 Ethereum II — 2021-10-20 – p.18/37
(m2 ) 1 1 — 3 BBc-1 Ethereum II —
2021-10-20 – p.19/37
IndivisibleAsset string public _name_; string public _symbol_; uint256 public _quantity_;
address public _owner_; _name_ ( ) _symbol_ _quantity_ (m2 ) _owner_ ‘_’ Solidity . . . — 3 BBc-1 Ethereum II — 2021-10-20 – p.20/37
IndivisibleAsset event Transfer(address indexed from, address indexed to); from to
indexed — 3 BBc-1 Ethereum II — 2021-10-20 – p.21/37
IndivisibleAsset constructor (string name, string symbol, uint256 quantity) public {
_name_ = name; _symbol_ = symbol; _quantity_ = quantity; _owner_ = msg.sender; } — 3 BBc-1 Ethereum II — 2021-10-20 – p.22/37
IndivisibleAsset getOwner() function getOwner() public view returns (address) { return
(_owner_); } — 3 BBc-1 Ethereum II — 2021-10-20 – p.23/37
IndivisibleAsset transfer() function transfer(address to) public returns (bool) { require(_owner_
== msg.sender); _owner_ = to; emit Transfer(msg.sender, to); return true; } require (function ) ( ) $ brownie compile — 3 BBc-1 Ethereum II — 2021-10-20 – p.24/37
scripts/indivisible asset.py from brownie import * def main(): accounts[0].deploy(IndivisibleAsset, "5322
Endo, Fujisawa", "mˆ2", 300) SFC (300m2 ) ( ) — 3 BBc-1 Ethereum II — 2021-10-20 – p.25/37
from brownie import * import pytest def test_owner_and_transfer(IndivisibleAsset): asset =
accounts[0].deploy(IndivisibleAsset, "5322 Endo", "mˆ2", 300) assert asset.getOwner() == accounts[0] asset.transfer(accounts[1], {’from’: accounts[0]}) assert asset.getOwner() == accounts[1] try: asset.transfer(accounts[0], {’from’: accounts[0]}) done = 1 except: done = 0 assert done == 0 accounts[0] accounts[1] — 3 BBc-1 Ethereum II — 2021-10-20 – p.26/37
$ pytest tests/test_indivisible_asset.py — 3 BBc-1 Ethereum II — 2021-10-20
– p.27/37
3. — 3 BBc-1 Ethereum II — 2021-10-20 – p.28/37
transfer settle, retrieve asset, retrieve token 3 — 3 BBc-1
Ethereum II — 2021-10-20 – p.29/37
1. ( ) 2. ( ) 3. ( ) —
3 BBc-1 Ethereum II — 2021-10-20 – p.30/37
OneTimeEscrow settle() function settle() public returns (bool) { require(_token_.balanceOf(address(this)) >=
_price_); /* this */ require(_asset_.getOwner() == address(this)); _token_.transfer(_seller_ , _price_); _asset_.transfer(_buyer_); emit Settled(); /* */ return true; } settle() transfer ( / ) $ brownie compile — 3 BBc-1 Ethereum II — 2021-10-20 – p.31/37
(1) from brownie import * import pytest def test_deploy_and_settle(Token, IndivisibleAsset,
OneTimeEscrow): asset = accounts[0].deploy(IndivisibleAsset, "5322 Endo", "mˆ2", 300) token = accounts[0].deploy(Token, "Test Token", "TEST", 18, "1000 ether") — 3 BBc-1 Ethereum II — 2021-10-20 – p.32/37
(2) token.transfer(accounts[1], 300, {’from’: accounts[0]}) escrow = accounts[0].deploy(OneTimeEscrow, token, accounts[1],
asset, accounts[0], 300) accounts[0] accounts[1] 300 300 TX accounts[1] accounts[0] 300 bake Token 300 ETH wei — 3 BBc-1 Ethereum II — 2021-10-20 – p.33/37
(3) token.transfer(escrow, 300, {’from’: accounts[1]}) asset.transfer(escrow, {’from’: accounts[0]}) assert token.balanceOf(accounts[0])
== 999999999999999999700 assert token.balanceOf(accounts[1]) == 0 assert token.balanceOf(escrow) == 300 assert asset.getOwner() == escrow accounts[1] ( ) 300 accounts[0] ( ) — 3 BBc-1 Ethereum II — 2021-10-20 – p.34/37
(4) escrow.settle({’from’: accounts[0]}) assert token.balanceOf(accounts[0]) == 1000000000000000000000 assert token.balanceOf(accounts[1]) ==
0 assert token.balanceOf(escrow) == 0 assert asset.getOwner() == accounts[1] settle() accounts[0] OK — 3 BBc-1 Ethereum II — 2021-10-20 – p.35/37
$ pytest tests/test_one_time_escrow.py : settle() — 3 BBc-1 Ethereum II
— 2021-10-20 – p.36/37
4 BBc-1 Ethereum III (1): (2): RFID — 3 BBc-1
Ethereum II — 2021-10-20 – p.37/37