Curve oracles
建立於 差異永不過期
// SPDX-License-Identifier: UNLICENSED
// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.6.12;
pragma solidity 0.6.12;
import "@openzeppelin/contracts-upgradeable/math/SafeMathUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/math/SafeMathUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
import "../external/compound/PriceOracle.sol";
import "../external/compound/PriceOracle.sol";
import "../external/compound/CToken.sol";
import "../external/compound/CToken.sol";
import "../external/compound/CErc20.sol";
import "../external/compound/CErc20.sol";
import "../external/curve/ICurveRegistry.sol";
import "../external/curve/ICurveFactoryRegistry.sol";
import "../external/curve/ICurvePool.sol";
import "../external/curve/ICurvePool.sol";
import "./BasePriceOracle.sol";
import "./BasePriceOracle.sol";
/**
/**
* @title CurveLpTokenPriceOracle
* @title CurveFactoryLpTokenPriceOracle
* @author David Lucid <david@rari.capital> (https://github.com/davidlucid)
* @author David Lucid <david@rari.capital> (https://github.com/davidlucid)
* @notice CurveLpTokenPriceOracle is a price oracle for Curve LP tokens (using the sender as a root oracle).
* @notice CurveFactoryLpTokenPriceOracle is a price oracle for Curve LP tokens (using the sender as a root oracle).
* @dev Implements the `PriceOracle` interface used by Fuse pools (and Compound v2).
* @dev Implements the `PriceOracle` interface used by Fuse pools (and Compound v2).
*/
*/
contract CurveLpTokenPriceOracle is PriceOracle, BasePriceOracle {
contract CurveFactoryLpTokenPriceOracle is PriceOracle, BasePriceOracle {
using SafeMathUpgradeable for uint256;
using SafeMathUpgradeable for uint256;
/**
/**
* @notice Get the LP token price price for an underlying token address.
* @notice Get the LP token price price for an underlying token address.
* @param underlying The underlying token address for which to get the price (set to zero address for ETH).
* @param underlying The underlying token address for which to get the price (set to zero address for ETH).
* @return Price denominated in ETH (scaled by 1e18).
* @return Price denominated in ETH (scaled by 1e18).
*/
*/
function price(address underlying) external override view returns (uint) {
function price(address underlying) external override view returns (uint) {
return _price(underlying);
return _price(underlying);
}
}
/**
/**
* @notice Returns the price in ETH of the token underlying `cToken`.
* @notice Returns the price in ETH of the token underlying `cToken`.
* @dev Implements the `PriceOracle` interface for Fuse pools (and Compound v2).
* @dev Implements the `PriceOracle` interface for Fuse pools (and Compound v2).
* @return Price in ETH of the token underlying `cToken`, scaled by `10 ** (36 - underlyingDecimals)`.
* @return Price in ETH of the token underlying `cToken`, scaled by `10 ** (36 - underlyingDecimals)`.
*/
*/
function getUnderlyingPrice(CToken cToken) external override view returns (uint) {
function getUnderlyingPrice(CToken cToken) external override view returns (uint) {
address underlying = CErc20(address(cToken)).underlying();
address underlying = CErc20(address(cToken)).underlying();
// Comptroller needs prices to be scaled by 1e(36 - decimals)
// Comptroller needs prices to be scaled by 1e(36 - decimals)
// Since `_price` returns prices scaled by 18 decimals, we must scale them by 1e(36 - 18 - decimals)
// Since `_price` returns prices scaled by 18 decimals, we must scale them by 1e(36 - 18 - decimals)
return _price(underlying).mul(1e18).div(10 ** uint256(ERC20Upgradeable(underlying).decimals()));
return _price(underlying).mul(1e18).div(10 ** uint256(ERC20Upgradeable(underlying).decimals()));
}
}
/**
/**
* @dev Fetches the fair LP token/ETH price from Curve, with 18 decimals of precision.
* @dev Fetches the fair LP token/ETH price from Curve, with 18 decimals of precision.
* Source: https://github.com/AlphaFinanceLab/homora-v2/blob/master/contracts/oracle/CurveOracle.sol
* Source: https://github.com/AlphaFinanceLab/homora-v2/blob/master/contracts/oracle/CurveOracle.sol
* @param lpToken The LP token contract address for price retrieval.
* @param pool pool LP token
*/
*/
function _price(address lpToken) internal view returns (uint) {
function _price(address pool) internal view returns (uint) {
address pool = poolOf[lpToken];
address[] memory tokens = underlyingTokens[pool];
require(pool != address(0), "LP token is not registered.");
require(tokens.length != 0, "LP token is not registered.");
address[] memory tokens = underlyingTokens[lpToken];
uint256 minPx = uint256(-1);
uint256 minPx = uint256(-1);
uint256 n = tokens.length;
uint256 n = tokens.length;
for (uint256 i = 0; i < n; i++) {
for (uint256 i = 0; i < n; i++) {
address ulToken = tokens[i];
address ulToken = tokens[i];
uint256 tokenPx = BasePriceOracle(msg.sender).price(ulToken);
uint256 tokenPx = BasePriceOracle(msg.sender).price(ulToken);
if (tokenPx < minPx) minPx = tokenPx;
if (tokenPx < minPx) minPx = tokenPx;
}
}
require(minPx != uint256(-1), "No minimum underlying token price found.");
require(minPx != uint256(-1), "No minimum underlying token price found.");
return minPx.mul(ICurvePool(pool).get_virtual_price()).div(1e18); // Use min underlying token prices
return minPx.mul(ICurvePool(pool).get_virtual_price()).div(1e18); // Use min underlying token prices
}
}
/**
/**
* @dev The Curve registry.
* @dev The Curve registry.
*/
*/
ICurveRegistry public constant registry = ICurveRegistry(0x7D86446dDb609eD0F5f8684AcF30380a356b2B4c);
ICurveFactoryRegistry public constant registry = ICurveFactoryRegistry(0xB9fC157394Af804a3578134A6585C0dc9cc990d4);
/**
/**
* @dev Maps Curve LP token addresses to underlying token addresses.
* @dev Maps Curve LP token addresses to underlying token addresses.
*/
*/
mapping(address => address[]) public underlyingTokens;
mapping(address => address[]) public underlyingTokens;
/**
/**
* @dev Maps Curve LP token addresses to pool addresses.
* @dev Maps Curve LP token addresses to pool addresses.
*/
*/
mapping(address => address) public poolOf;
mapping(address => address) public poolOf;
/**
/**
* @dev Register the pool given LP token address and set the pool info.
* @dev Register the pool given LP token address and set the pool info.
* Source: https://github.com/AlphaFinanceLab/homora-v2/blob/master/contracts/oracle/CurveOracle.sol
* Source: https://github.com/AlphaFinanceLab/homora-v2/blob/master/contracts/oracle/CurveOracle.sol
* @param lpToken LP token to find the corresponding pool.
* @param pool pool LP token
*/
*/
function registerPool(address lpToken) external {
function registerPool(address pool) external {
address pool = poolOf[lpToken];
require(pool == address(0), "This LP token is already registered.");
pool = registry.get_pool_from_lp_token(lpToken);
require(pool != address(0), "No corresponding pool found for this LP token in the Curve registry.");
poolOf[lpToken] = pool;
uint n = registry.get_n_coins(pool);
uint n = registry.get_n_coins(pool);
address[8] memory tokens = registry.get_coins(pool);
require(n != 0, "n");
for (uint256 i = 0; i < n; i++) underlyingTokens[lpToken].push(tokens[i]);
address[4] memory tokens = registry.get_coins(pool);
for (uint256 i = 0; i < n; i++) underlyingTokens[pool].push(tokens[i]);
}
}
}
}