/// @inheritdoc IUniswapV3Factory
address public override owner;
根据费率设置的不同的 tickSpacing 间隔
/// @inheritdoc IUniswapV3Factory
mapping(uint24 => int24) public override feeAmountTickSpacing;
初始化代码
contsructor() {
...
feeAmountTickSpacing[500] = 10;
feeAmountTickSpacing[3000] = 60;
feeAmountTickSpacing[10000] = 200;
}
Pool的地址索引,通过 tokenA
, tokenB
, fee
三个键查找
/// @inheritdoc IUniswapV3Factory
mapping(address => mapping(address => mapping(uint24 => address))) public override getPool;
存储Pool初始化的参数
struct Parameters {
address factory;
address token0;
address token1;
uint24 fee;
int24 tickSpacing;
}
/// @inheritdoc IUniswapV3PoolDeployer
Parameters public override parameters;
通过token交易对(顺序不影响),fee费率,三个参数部署Pool合约
/// @inheritdoc IUniswapV3Factory
function createPool(
address tokenA,
address tokenB,
uint24 fee
) external override noDelegateCall returns (address pool) {
// 需要两种不同token
require(tokenA != tokenB);
// 对token地址排序
(address token0, address token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
// tokenA地址不能为 0 因为B比A大 所以只用断言一个
require(token0 != address(0));
// 根据费率设定Pool的tickSpacing
int24 tickSpacing = feeAmountTickSpacing[fee];
require(tickSpacing != 0);
// 查询该Pool地址 地址必须为 0 否则说明Pool已创建
require(getPool[token0][token1][fee] == address(0));
// 部署Pool合约
pool = deploy(address(this), token0, token1, fee, tickSpacing);
getPool[token0][token1][fee] = pool;
// populate mapping in the reverse direction, deliberate choice to avoid the cost of comparing addresses
getPool[token1][token0][fee] = pool;
emit PoolCreated(token0, token1, fee, tickSpacing, pool);
}
部署 UniswapV3Pool
合约
- 先将初始化参数存入storage,方便Pool合约初始化时调用,部署完成后,清除storage
- 不直接传入初始化参数的原因是这里使用了
CREATE2
来部署合约,CREATE2
会将合约的initcode
(包含constructor的参数) 和salt
一起用来计算创建出的合约地址 - 使用
CREATE2
的优势:- 可以在链下计算出已经创建的交易池的地址
- 其他合约不必通过 UniswapV3Factory 中的接口来查询交易池的地址,可以节省 gas
- 合约地址不会因为 reorg 而改变
/// @dev Deploys a pool with the given parameters by transiently setting the parameters storage slot and then
/// clearing it after deploying the pool.
/// @param factory The contract address of the Uniswap V3 factory
/// @param token0 The first token of the pool by address sort order
/// @param token1 The second token of the pool by address sort order
/// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
/// @param tickSpacing The spacing between usable ticks
function deploy(
address factory,
address token0,
address token1,
uint24 fee,
int24 tickSpacing
) internal returns (address pool) {
// 将初始化参数存入storage
parameters = Parameters({factory: factory, token0: token0, token1: token1, fee: fee, tickSpacing: tickSpacing});
// 使用 CREATE2 指令部署Pool合约
// Pool初始化时 会访问storage中的初始化参数
pool = address(new UniswapV3Pool{salt: keccak256(abi.encode(token0, token1, fee))}());
// 部署完成 清除storage
delete parameters;
}
相关代码
补充
- 关于使用 salt 创建合约的解释:Salted contract creations / create2