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 Exe...
Search
Kenji Saito
PRO
September 28, 2022
Technology
0
110
BBc-1 と Ethereum 演習 II / BBc-1 and Ethereum Exercise II
2022年9月28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にて使用したスライドです。
Kenji Saito
PRO
September 28, 2022
Tweet
Share
More Decks by Kenji Saito
See All by Kenji Saito
マニフェスト: 人類の知のフロンティアに向けた拡張的足場へ / Manifesto: Toward Expansive Scaffolding for Humanity's Knowledge Frontier
ks91
PRO
0
8
続・スマートコントラクトと分散ファイナンス / Smart Contracts and Decentralized Finance, Continued
ks91
PRO
0
42
スマートコントラクトと分散ファイナンス / Smart Contracts and Decentralized Finance
ks91
PRO
0
63
シン・ブロックチェーン / Truth of Blockchain
ks91
PRO
0
92
パスワード/パスフレーズと認証 / Password, Passphrase and Authentication
ks91
PRO
0
37
git と GitHub / git and GitHub
ks91
PRO
0
35
ソフトウェアの開発と保守 / Software Development and Maintenance
ks91
PRO
0
50
インターネットの特徴 / Features of the Internet
ks91
PRO
0
34
インターネットのガバナンス / Governance of the Internet
ks91
PRO
0
30
Other Decks in Technology
See All in Technology
LangSmith×Webhook連携で実現するプロンプトドリブンCI/CD
sergicalsix
1
230
united airlines ™®️ USA Contact Numbers: Complete 2025 Support Guide
flyunitedhelp
1
300
生成AI開発案件におけるClineの業務活用事例とTips
shinya337
0
250
United Airlines Customer Service– Call 1-833-341-3142 Now!
airhelp
0
170
タイミーのデータモデリング事例と今後のチャレンジ
ttccddtoki
6
2.4k
生成AI活用の組織格差を解消する 〜ビジネス職のCursor導入が開発効率に与えた好循環〜 / Closing the Organizational Gap in AI Adoption
upamune
7
5.2k
成長し続けるアプリのためのテストと設計の関係、そして意思決定の記録。
sansantech
PRO
0
120
無意味な開発生産性の議論から抜け出すための予兆検知とお金とAI
i35_267
4
13k
生まれ変わった AWS Security Hub (Preview) を紹介 #reInforce_osaka / reInforce New Security Hub
masahirokawahara
0
470
CRE Camp #1 エンジニアリングを民主化するCREチームでありたい話
mntsq
1
120
LangChain Interrupt & LangChain Ambassadors meetingレポート
os1ma
2
310
20250705 Headlamp: 專注可擴展性的 Kubernetes 用戶界面
pichuang
0
270
Featured
See All Featured
Testing 201, or: Great Expectations
jmmastey
43
7.6k
Let's Do A Bunch of Simple Stuff to Make Websites Faster
chriscoyier
507
140k
The Art of Programming - Codeland 2020
erikaheidi
54
13k
Writing Fast Ruby
sferik
628
62k
Making the Leap to Tech Lead
cromwellryan
134
9.4k
Mobile First: as difficult as doing things right
swwweet
223
9.7k
Measuring & Analyzing Core Web Vitals
bluesmoon
7
510
Automating Front-end Workflow
addyosmani
1370
200k
RailsConf 2023
tenderlove
30
1.1k
Making Projects Easy
brettharned
116
6.3k
Docker and Python
trallard
44
3.5k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
29
1.8k
Transcript
3 BBc-1 Ethereum II CSO /
[email protected]
— 3 BBc-1
Ethereum II — 2022-09-28 – p.1/37
https://speakerdeck.com/ks91 — 3 BBc-1 Ethereum II — 2022-09-28 – p.2/37
( ) SFC ( ) CSO (Chief Science Officer) 1993
( ) 2006 ( ) SFC 22 P2P (Peer-to-Peer) 2011 ( ) 2018 2019 VR 2021.7 VR 2021.8 “ALL THESE WORLDS ARE YOURS” VR 2021.9 & VR 2021.12 VR 2022.3 VR 2022.8 → ( ) — 3 BBc-1 Ethereum II — 2022-09-28 – p.3/37
BBc-1 Ethereum 3 Ethereum — 3 BBc-1 Ethereum II —
2022-09-28 – p.4/37
1. : ERC-20 2. : 3. : — 3 BBc-1
Ethereum II — 2022-09-28 – p.5/37
1. : ERC-20 $ brownie bake token — 3 BBc-1
Ethereum II — 2022-09-28 – p.6/37
Solidity JavaScript ( , ) (constructor) ( ) ( )
Ether Ethereum — 3 BBc-1 Ethereum II — 2022-09-28 – 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 — 2022-09-28 – p.8/37
ERC-20 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 ERC-777 ( ) — 3 BBc-1 Ethereum II — 2022-09-28 – p.9/37
ERC-20 ERC-20 ( ) ⇒ ERC-20 ( ERC-20 ) ERC-20
⇒ — 3 BBc-1 Ethereum II — 2022-09-28 – p.10/37
(fungible) ERC-20 → ERC-223 (draft) or ERC-777 ( )( )
(non-fungible) ERC-721 ( ) ERC-1155 ( ) ERC-3525 (SLOT ) — 3 BBc-1 Ethereum II — 2022-09-28 – 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 — 2022-09-28 – p.12/37
Token ( ) event Transfer(address from, address to, uint256 value);
Token function emit Transfer() ( ) — 3 BBc-1 Ethereum II — 2022-09-28 – 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 — 2022-09-28 – p.14/37
Token balanceOf() function balanceOf(address _owner) public view returns (uint256) {
return balances[_owner]; } — 3 BBc-1 Ethereum II — 2022-09-28 – p.15/37
Token transfer() function transfer(address _to, uint256 _value) public returns (bool)
{ require(balances[msg.sender] >= _value, "Insufficient balance"); balances[msg.sender] = balances[msg.sender].sub(_value); balances[_to] = balances[_to].add(_value); emit Transfer(msg.sender, _to, _value); return true; } require (function ) ( ↑ ) OpenZeppelin https://openzeppelin.org — 3 BBc-1 Ethereum II — 2022-09-28 – p.16/37
2. — 3 BBc-1 Ethereum II — 2022-09-28 – 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 — 2022-09-28 – p.18/37
(m2 ) 1 1 — 3 BBc-1 Ethereum II —
2022-09-28 – 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 — 2022-09-28 – p.20/37
IndivisibleAsset event Transfer(address indexed from, address indexed to); from to
indexed — 3 BBc-1 Ethereum II — 2022-09-28 – 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 — 2022-09-28 – p.22/37
IndivisibleAsset getOwner() function getOwner() public view returns (address) { return
(_owner_); } — 3 BBc-1 Ethereum II — 2022-09-28 – 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 — 2022-09-28 – 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 — 2022-09-28 – 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 — 2022-09-28 – p.26/37
$ pytest tests/test_indivisible_asset.py — 3 BBc-1 Ethereum II — 2022-09-28
– p.27/37
3. — 3 BBc-1 Ethereum II — 2022-09-28 – p.28/37
transfer settle, retrieve asset, retrieve token 3 — 3 BBc-1
Ethereum II — 2022-09-28 – p.29/37
1. ( ) 2. ( ) 3. ( ) —
3 BBc-1 Ethereum II — 2022-09-28 – 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 — 2022-09-28 – 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 — 2022-09-28 – 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 — 2022-09-28 – 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 — 2022-09-28 – 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 — 2022-09-28 – p.35/37
$ pytest tests/test_one_time_escrow.py : settle() — 3 BBc-1 Ethereum II
— 2022-09-28 – p.36/37
4 BBc-1 Ethereum III (1): NFT (2): DAO — 3
BBc-1 Ethereum II — 2022-09-28 – p.37/37