2.1.1 安裝
$ git clone admin@chaindaily:paritytech/frontier.git
$ cd frontier
(master)$ git log
commit fcea97281661f0a0a4c28e46edbfb1238043471e
Author: Wei Tang <admin@chaindaily>
Date: Tue Jul 14 13:25:48 2020 +0200
(master)$ git submodule init
子模組 'vendor/ethereum' (https://github.com/rust-blockchain/ethereum) 已為路徑 'vendor/ethereum' 註冊
子模組 'vendor/evm' (https://github.com/rust-blockchain/evm) 已為路徑 'vendor/evm' 註冊
子模組 'vendor/substrate' (https://github.com/paritytech/substrate) 已為路徑 'vendor/substrate' 註冊
(master)$ git submodule update
正克隆到 'vendor/ethereum'...
處理 delta 中: 100% (930/930), done.
子模組路徑 'vendor/ethereum'：檢出 '4fdd3c8ac849f91f5352bc7dfc189144a09aac1e'
正克隆到 'vendor/evm'...
子模組路徑 'vendor/evm'：檢出 '84013f3ea23e436541f409c717134dd1536143de'
正克隆到 'vendor/substrate'...
fatal: 引用不是一個樹：b36fc2c849ae0cba434bb3ce82e0a4dda5bcbe7a
無法在子模組路徑 'vendor/substrate' 中檢出 'b36fc2c849ae0cba434bb3ce82e0a4dda5bcbe7a'
# 獲取子模組有報錯，單獨clone substrate工程來解決
$ cd vendor
$ /bin/rm -rf substrate
$ git clone admin@chaindaily:paritytech/substrate.git
# 注意：這裡不能切換到最新的tag（v2.0.0-rc4），編譯會報錯，採用當前最新的master分支，可以正常編譯frontier
[admin@chaindaily:~/frontier/vendor/substrate] (master)$ git log
commit 9b5a9cb9056f8ab049837d30b500fca78a6c362c
Author: Shawn Tabrizi <admin@chaindaily>
Date: Thu Jul 16 02:21:15 2020 +0200
2.1.2 新增個人賬號
在substrate frontier鏈的創世配置裡面，內建我們在MetaMask上的自有賬號，並初始化配置上足夠的ETH數量，以便我們開發測試的需要。
•複製個人測試賬號地址
0x888a0bF014d1D6334002261BaC34a16f5Ce963ac
•修改frontier/template/node/src/chain_spec.rs，新增以下內容：
+ 29 use std::str::FromStr;
! 141 let built_in_evm_account =
! 142 h260::from_str("888a0bF014d1D6334002261BaC34a16f5Ce963ac").unwrap();
! 143 let mut evm_accounts = BTreeMap::new();
! 144 //let ten: u128 = 10;
! 145 evm_accounts.insert(
! 146 built_in_evm_account,
! 147 evm::GenesisAccount {
! 148 nonce: 0.into(),
! 149 balance: (2018030320150719 as u128 * 10_u128.pow(18)).into(), // 設定賬戶初始ETH餘額，注意ETH有18位小數
! 150 storage: BTreeMap::new(),
! 151 code: WASM_BINARY.to_vec(),
! 152 },
! 153 );
2.1.3 編譯
$ cargo build --release
2.1.4 執行
(master)$ ./target/release/frontier-template-node purge-chain --dev
Are you sure to remove "/root/.local/share/frontier-template-node/chains/dev/db"? [y/N]: y
"/root/.local/share/frontier-template-node/chains/dev/db" did not exist.
(master)$ ./target/release/frontier-template-node --dev --ws-external --rpc-external --rpc-cors=all
2020-07-18 22:59:28 Substrate Node
2020-07-18 22:59:28 version 2.0.0-dev-fcea972-x86_64-linux-gnu
2020-07-18 22:59:28 by Parity Technologies <admin@chaindaily>, 2017-2020
2020-07-18 22:59:28 Chain specification: Development
2020-07-18 22:59:28 Node name: stimulating-hand-5352
2020-07-18 22:59:28 Role: AUTHORITY
2020-07-18 22:59:28 Database: RocksDb at /root/.local/share/frontier-template-node/chains/dev/db
2020-07-18 22:59:28 Native runtime: node-frontier-template-1 (node-frontier-template-1.tx1.au1)
2020-07-18 22:59:28 Initializing Genesis block/state (state: 0x1e15…857d, header-hash: 0xa26e…22df)
2020-07-18 22:59:28 Loading GRANDPA authority set from genesis on what appears to be first startup.
2020-07-18 22:59:29 Loaded block-time = 6000 milliseconds from genesis on first-launch
2020-07-18 22:59:29 Highest known block at #0
2020-07-18 22:59:29 Using default protocol ID "sup" because none is configured in the chain specs
2020-07-18 22:59:29 Local node identity is: 12D3KooWMgcWheT7cvvpaaKmqNLVPRpAkGLR9V1M7pfs43DxZU6c (legacy representation: QmRN3jaSxZV5dMk1P5tm1CB9oud8pU8SGZvrUFfuS9dNMQ)
2020-07-18 22:59:29 Prometheus server started at 127.0.0.1:9615
2020-07-18 22:59:30 Starting consensus session on top of parent 0xa26e0b7f2abed8a4bcf87ca45d20d7628cf22225dd522385e7b49ee6c30522df
2020-07-18 22:59:30 Prepared block for proposing at 1 [hash: 0xd3558be2df939b94ba94d82ded332216b0b06a55596d0a61a858aeaf7acc16c4; parent_hash: 0xa26e…22df; extrinsics (1): [0xead1…ac1b]]
2020-07-18 22:59:30 Pre-sealed block for proposal at 1. Hash now 0x8aa38d1228213371249ff83404bd8576e3e0bce6e120f93a9fe08ec2dfdc2d86, previously 0xd3558be2df939b94ba94d82ded332216b0b06a55596d0a61a858aeaf7acc16c4.
2020-07-18 22:59:30 Imported #1 (0x8aa3…2d86)
2020-07-18 22:59:34 Idle (0 peers), best: #1 (0x8aa3…2d86), finalized #0 (0xa26e…22df), ⬇ 0 ⬆ 0
2020-07-18 22:59:36 Starting consensus session on top of parent 0x8aa38d1228213371249ff83404bd8576e3e0bce6e120f93a9fe08ec2dfdc2d86
2020-07-18 22:59:36 Prepared block for proposing at 2 [hash: 0x570be59726cf2018fab9e7bae77208a990921291fe8164bbc1df253f8142d3f6; parent_hash: 0x8aa3…2d86; extrinsics (1): [0xec7f…0d17]]
2020-07-18 22:59:36 Pre-sealed block for proposal at 2. Hash now 0xe9831c239f29745d79b0e72cc26c0db19ce4d0c7712a32dae4cc60f8ad538551, previously 0x570be59726cf2018fab9e7bae77208a990921291fe8164bbc1df253f8142d3f6.
2020-07-18 22:59:36 Imported #2 (0xe983…8551)
2.2 MetaMask接入frontier鏈
2.2.1 配置自定義RPC接入
這裡ChainID填42，源於runtime中的定義：
parameter_types! {
pub const EVMModuleId: ModuleId = ModuleId(*b"py/evmpa");
pub const ChainId: u64 = 42;
}
impl evm::Trait for Runtime {
type ModuleId = EVMModuleId;
type FeeCalculator = FixedGasPrice;
type ConvertAccountId = HashTruncateConvertAccountId<BlakeTwo256>;
type Currency = Balances;
type Event = Event;
type Precompiles = ();
type ChainId = ChainId;
}
2.2.2 檢視賬戶餘額
2.2.3 開啟Gas控制高階選項
開啟該選項後，以便我們隨意配置gas limit和gas price：
2.3 remix接入MetaMask
•使用Injected Web3建立與MetaMask賬號的連線
我們看到我們建立的賬號已經成功接入remix，接下來，我們便可以進行ERC20合約的開發和部署了。
3 合約開發&部署
3.1 智慧合約編寫
我們要編寫兩個合約，其中SafeMath.sol是一個算數運算防溢位的安全庫，xyc.sol是一個ERC20智慧合約。
3.1.1 SafeMath.sol
pragma solidity ^0.6.0;
library SafeMath {
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
return c;
}
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
3.1.2 xyc.sol
pragma solidity ^0.6.0;
import "./SafeMath.sol";
abstract contract ERC20 {
function totalSupply() public virtual view returns (uint256);
function balanceOf(address owner) public virtual view returns (uint256);
function transfer(address to, uint256 value) public virtual returns (bool);
function transferFrom(address from, address to, uint256 value) public virtual returns (bool);
function approve(address spender, uint256 value) public virtual returns (bool);
function allowance(address owner, address spender) public virtual view returns (uint256);
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
contract xyc is ERC20 {
using SafeMath for uint256;
string name = "XuanYuan Coin";
string symbol = "xyc";
uint8 decimals;
uint256 private _totalSupply;
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
constructor(uint256 myTotalSupply, uint8 mydecimals) public {
_totalSupply = myTotalSupply;
decimals = mydecimals;
_balances[msg.sender] = myTotalSupply;
}
function totalSupply() public override view returns (uint256) {
return _totalSupply;
}
function balanceOf(address _owner) public override view returns (uint256) {
return _balances[_owner];
}
function transfer(address to, uint256 value) public override returns (bool) {
require(to != address(0), "ERC20 ERROR: transfer from zero address");
require(value <= _balances[msg.sender]);
require(_balances[to] + value >= _balances[to]);
_balances[msg.sender] = _balances[msg.sender].sub(value);
_balances[to] = _balances[to].add(value);
emit Transfer(msg.sender, to, value);
return true;
}
function transferFrom(address from, address to, uint256 value) public override returns (bool) {
require(to != address(0));
require(value <= _balances[from]);
require(value <= _allowances[from][msg.sender]);
require(_balances[to] + value >= _balances[to]);
_balances[from] = _balances[from].sub(value);
_balances[to] = _balances[to].add(value);
_allowances[from][msg.sender] = _allowances[from][msg.sender].sub(value);
emit Transfer(from, to, value);
return true;
}
function approve(address spender, uint256 value) public override returns (bool) {
require(value <= _balances[msg.sender]);
_allowances[msg.sender][spender] = value;
emit Approval(msg.sender, spender, value);
return true;
}
function allowance(address _owner, address spender) public override view returns (uint256) {
return _allowances[_owner][spender];
}
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
3.2 智慧合約編譯
智慧合約編譯成功，接下來我們就將已經開發完成的Solidity ERC20智慧合約部署到Substrate鏈上。
3.3 智慧合約部署
•選擇要部署的合約，填寫構造方法中的發行總量和精度兩個引數，點選transact按鈕
注：當前版本需要在彈出的MetaMask對話方塊上，設定很大的gas limit值（4294967295）才能部署成功:(
4 合約功能測試
透過remix完成對ERC20合約的功能測試。
4.1 檢視發行量&餘額
可見所有發行代幣都歸屬於合約部署方地址。
4.2 轉賬測試
•給賬戶2：0x8A832874304Be72b299C0ED96f22B11311c9051C，轉賬1000.00 XYC，檢視賬戶1地址XYC代幣數量為：9000.00，符合預期
•在MetaMask上新增自定義代幣
合約地址：0xfE2dF1EE3783eBD46481e32d849acB49ec5004Bf
•代幣發行方地址所剩代幣為：9000.00 XYC
•代幣接收方地址代幣數量為：1000.00 XYC
4.3 授權代理轉賬測試
•為賬戶2轉賬ETH，用於支付gas費
•使用者1授權使用者2可代理轉賬的代幣數量為2000.00 XYC
•檢視使用者2所能授權轉賬使用者1的XYC代幣
•使用者2代理使用者1給使用者3轉賬2000.00 XYC
成功轉賬後，檢視到使用者2所能授權轉賬使用者1的XYC代幣數量為0
•檢視到賬戶3上XYC代幣餘額
•再次檢視賬戶1上的代幣餘額
