本实践案例中,我们首先会搭建和启动一条substrate链,再通过MetaMask这款著名的以太坊钱包浏览器插件,通过自定义RPC的方式,接入我们搭建好的substrate链。 然后我们会在remix这款智能合约在线IDE上的完成ERC20智能合约的开发、编译、部署、调试。remix将通过Injected Web3的方式接入我们的MetaMask钱包,借助MetaMask实现和substrate链的交互。
在Substrate链上跑Solidity ERC20智能合约
jasonruan 2020.07.18
本实践案例中,我们首先会搭建和启动一条substrate
链,再通过MetaMask
这款著名的以太坊钱包浏览器插件,通过自定义RPC
的方式,接入我们搭建好的substrate
链。
然后我们会在remix
这款智能合约在线IDE
上的完成ERC20
智能合约的开发、编译、部署、调试。remix
将通过Injected Web3
的方式接入我们的MetaMask
钱包,借助MetaMask
实现和substrate
链的交互。
由于Substrate的
runtime
没有集成EVM
,需要使用Parity
另外一个项目:Frontier。Frontier
是Substrate
的以太坊兼容层。在这个项目中,增加了
pallet-evm
、pallet-ethereum
、rpc-ethereum
,可以最大程度的模拟以太坊的环境,以便可以无缝对接当前以太坊生态里面DApp
及第三方工具,如remix
、metamask
等。
$ git clone git@github.com:paritytech/frontier.git
$ cd frontier
(master)$ git log
commit fcea97281661f0a0a4c28e46edbfb1238043471e
Author: Wei Tang <wei@that.world>
Date: Tue Jul 14 13:25:48 2020 +0200
(master)$ git submodule init
子模组 'vendor/ethereum' (https://github.com/rust-blockchain/ethereum) 已为路径 'vendor/ethereum' 注册
子模组 'vendor/evm' (https://github.com/rust-blockchain/evm) 已为路径 'vendor/evm' 注册
子模组 'vendor/substrate' (https://github.com/paritytech/substrate) 已为路径 'vendor/substrate' 注册
(master)$ git submodule update
正克隆到 'vendor/ethereum'...
处理 delta 中: 100% (930/930), done.
子模组路径 'vendor/ethereum':检出 '4fdd3c8ac849f91f5352bc7dfc189144a09aac1e'
正克隆到 'vendor/evm'...
子模组路径 'vendor/evm':检出 '84013f3ea23e436541f409c717134dd1536143de'
正克隆到 'vendor/substrate'...
fatal: 引用不是一个树:b36fc2c849ae0cba434bb3ce82e0a4dda5bcbe7a
无法在子模组路径 'vendor/substrate' 中检出 'b36fc2c849ae0cba434bb3ce82e0a4dda5bcbe7a'
# 获取子模块有报错,单独clone substrate工程来解决
$ cd vendor
$ /bin/rm -rf substrate
$ git clone git@github.com:paritytech/substrate.git
# 注意:这里不能切换到最新的tag(v2.0.0-rc4),编译会报错,采用当前最新的master分支,可以正常编译frontier
[Jason@RUAN:~/frontier/vendor/substrate] (master)$ git log
commit 9b5a9cb9056f8ab049837d30b500fca78a6c362c
Author: Shawn Tabrizi <shawntabrizi@gmail.com>
Date: Thu Jul 16 02:21:15 2020 +0200
在substrate frontier链的创世配置里面,内建我们在MetaMask上的自有账号,并初始化配置上足够的ETH数量,以便我们开发测试的需要。
拷贝个人测试账号地址
0x888a0bF014d1D6334002261BaC34a16f5Ce963ac
frontier/template/node/src/chain_spec.rs
,添加以下内容:+ 29 use std::str::FromStr;
! 141 let built_in_evm_account =
! 142 H160::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(), // 设置账户初始ETH余额,注意ETH有18位小数
! 150 storage: BTreeMap::new(),
! 151 code: WASM_BINARY.to_vec(),
! 152 },
! 153 );
$ cargo build --release
(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@parity.io>, 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)
这里
ChainID
填42,源于runtime
中的定义: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; }
开启该选项后,以便我们随意配置
gas limit
和gas price
:
Injected Web3
建立与MetaMask
账号的连接我们看到我们创建的账号已经成功接入remix
,接下来,我们便可以进行ERC20
合约的开发和部署了。
我们要编写两个合约,其中SafeMath.sol
是一个算数运算防溢出的安全库,xyc.sol
是一个ERC20
智能合约。
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;
}
}
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);
}
智能合约编译成功,接下来我们就将已经开发完成的Solidity ERC20
智能合约部署到Substrate
链上。
transact
按钮注:当前版本需要在弹出的MetaMask对话框上,设置很大的gas limit值(
4294967295
)才能部署成功:(
通过remix
完成对ERC20
合约的功能测试。
可见所有发行代币都归属于合约部署方地址。
0x8A832874304Be72b299C0ED96f22B11311c9051C
,转账1000.00 XYC,查看账户1地址XYC代币数量为:9000.00,符合预期合约地址:
0xfE2dF1EE3783eBD46481e32d849acB49ec5004Bf
账号 | 地址 |
---|---|
Jasonruan | 0x888a0bF014d1D6334002261BaC34a16f5Ce963ac |
Account 2 | 0x8A832874304Be72b299C0ED96f22B11311c9051C |
Account 3 | 0x6Be02d1d3665660d22FF9624b7BE0551ee1Ac91b |
成功转账后,查看到用户2所能授权转账用户1的XYC代币数量为0
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