Contract Name:
ChainlinkOracle
Contract Source Code:
// SPDX-License-Identifier: CC0-1.0
pragma solidity 0.8.15;
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "../interfaces/external/chainlink/IAggregatorV3.sol";
import "../interfaces/oracles/IOracle.sol";
/// @notice Contract for getting chainlink data
contract ChainlinkOracle is IOracle, Ownable {
/// @notice Thrown when tokens.length != oracles.length
error InvalidLength();
/// @notice Thrown when price feed doesn't work by some reason
error InvalidOracle();
/// @notice Thrown when sum of token.decimals and oracle.decimals is too high
error InvalidOverallDecimals();
/// @notice Price update error
error PriceUpdateFailed();
uint256 public constant DECIMALS = 18;
uint256 public constant Q96 = 2**96;
struct PriceData {
IAggregatorV3 feed;
uint48 heartbeat;
uint48 fallbackUpdatedAt;
uint256 fallbackPriceX96;
uint256 priceMultiplier;
}
/// @notice Mapping, returning underlying prices for each token
mapping(address => PriceData) public pricesInfo;
/// @notice Valid period of underlying prices (in seconds)
uint256 public validPeriod;
/// @notice Creates a new contract
/// @param tokens Initial supported tokens
/// @param oracles Initial approved Chainlink oracles
/// @param heartbeats Initial heartbeats for chainlink oracles
/// @param validPeriod_ Initial valid period of underlying prices (in seconds)
constructor(
address[] memory tokens,
address[] memory oracles,
uint48[] memory heartbeats,
uint256 validPeriod_
) {
validPeriod = validPeriod_;
_addChainlinkOracles(tokens, oracles, heartbeats);
}
// ------------------------- EXTERNAL, VIEW ------------------------------
/// @inheritdoc IOracle
function hasOracle(address token) external view returns (bool) {
return address(pricesInfo[token].feed) != address(0);
}
/// @inheritdoc IOracle
function price(address token) external view returns (bool success, uint256 priceX96) {
PriceData storage priceData = pricesInfo[token];
(IAggregatorV3 feed, uint48 heartbeat, uint48 fallbackUpdatedAt) = (
priceData.feed,
priceData.heartbeat,
priceData.fallbackUpdatedAt
);
uint256 oraclePrice;
uint256 updatedAt;
if (address(priceData.feed) == address(0)) {
return (false, 0);
}
(success, oraclePrice, updatedAt) = _queryChainlinkOracle(feed);
if (!success || updatedAt + heartbeat < block.timestamp) {
if (block.timestamp <= fallbackUpdatedAt + validPeriod) {
return (true, priceData.fallbackPriceX96);
} else {
return (false, 0);
}
}
success = true;
priceX96 = oraclePrice * priceData.priceMultiplier;
}
// ------------------------- EXTERNAL, MUTATING ------------------------------
/// @notice Add more chainlink oracles and tokens
/// @param tokens Array of new tokens
/// @param oracles Array of new oracles
/// @param heartbeats Array of heartbeats for oracles
function addChainlinkOracles(
address[] memory tokens,
address[] memory oracles,
uint48[] memory heartbeats
) external onlyOwner {
_addChainlinkOracles(tokens, oracles, heartbeats);
}
/// @notice Set new valid period
/// @param validPeriod_ New valid period
function setValidPeriod(uint256 validPeriod_) external onlyOwner {
validPeriod = validPeriod_;
emit ValidPeriodUpdated(tx.origin, msg.sender, validPeriod_);
}
/// @notice Set new underlying fallbackPriceX96 for specific token
/// @param token Address of the token
/// @param fallbackPriceX96 Value of price multiplied by 2**96
/// @param fallbackUpdatedAt Timestamp of the price
function setUnderlyingPriceX96(
address token,
uint256 fallbackPriceX96,
uint48 fallbackUpdatedAt
) external onlyOwner {
if (fallbackUpdatedAt >= block.timestamp) {
fallbackUpdatedAt = uint48(block.timestamp);
} else if (fallbackUpdatedAt + validPeriod < block.timestamp) {
revert PriceUpdateFailed();
}
PriceData storage priceData = pricesInfo[token];
priceData.fallbackUpdatedAt = fallbackUpdatedAt;
priceData.fallbackPriceX96 = fallbackPriceX96;
emit PricePosted(tx.origin, msg.sender, token, fallbackPriceX96, fallbackUpdatedAt);
}
// ------------------------- INTERNAL, VIEW ------------------------------
/// @notice Attempt to send a price query to chainlink oracle
/// @param oracle Chainlink oracle
/// @return success Query to chainlink oracle (if oracle.latestRoundData call works correctly => the answer can be received), answer Result of the query
function _queryChainlinkOracle(IAggregatorV3 oracle)
internal
view
returns (
bool success,
uint256 answer,
uint256 fallbackUpdatedAt
)
{
try oracle.latestRoundData() returns (uint80, int256 ans, uint256, uint256 fallbackUpdatedAt_, uint80) {
if (ans <= 0) {
return (false, 0, 0);
}
return (true, uint256(ans), fallbackUpdatedAt_);
} catch (bytes memory) {
return (false, 0, 0);
}
}
// ------------------------- INTERNAL, MUTATING ------------------------------
/// @notice Add more chainlink oracles and tokens (internal)
/// @param tokens Array of new tokens
/// @param oracles Array of new oracles
/// @param heartbeats Array of heartbeats for oracles
function _addChainlinkOracles(
address[] memory tokens,
address[] memory oracles,
uint48[] memory heartbeats
) internal {
if (tokens.length != oracles.length || oracles.length != heartbeats.length) {
revert InvalidLength();
}
for (uint256 i = 0; i < tokens.length; ++i) {
address token = tokens[i];
address oracle = oracles[i];
uint48 heartbeat = heartbeats[i];
IAggregatorV3 chainlinkOracle = IAggregatorV3(oracle);
(bool flag, , ) = _queryChainlinkOracle(chainlinkOracle);
if (!flag) {
revert InvalidOracle(); // hence a token for this 'oracle' can not be added
}
uint256 decimals = uint256(IERC20Metadata(token).decimals() + IAggregatorV3(oracle).decimals());
// when decimals is more than 18 + 26 priceDeviation becomes too high
if (decimals > 44) {
revert InvalidOverallDecimals();
}
uint256 priceMultiplier;
if (DECIMALS > decimals) {
priceMultiplier = (10**(DECIMALS - decimals)) * Q96;
} else {
priceMultiplier = Q96 / 10**(decimals - DECIMALS);
}
pricesInfo[token] = PriceData({
feed: chainlinkOracle,
heartbeat: heartbeat,
fallbackUpdatedAt: 0,
fallbackPriceX96: 0,
priceMultiplier: priceMultiplier
});
}
emit OraclesAdded(tx.origin, msg.sender, tokens, oracles, heartbeats);
}
// -------------------------- EVENTS --------------------------
/// @notice Emitted when new Chainlink oracles are added
/// @param origin Origin of the transaction (tx.origin)
/// @param sender Sender of the call (msg.sender)
/// @param tokens Tokens added
/// @param oracles Oracles added for the tokens
/// @param heartbeats Array of heartbeats for oracles
event OraclesAdded(
address indexed origin,
address indexed sender,
address[] tokens,
address[] oracles,
uint48[] heartbeats
);
/// @notice Emitted when underlying price of the token updates
/// @param origin Origin of the transaction (tx.origin)
/// @param sender Sender of the call (msg.sender)
/// @param token Address of the token
/// @param newPriceX96 New underlying price multiplied by 2**96
/// @param fallbackUpdatedAt Timestamp of underlying price updating
event PricePosted(
address indexed origin,
address indexed sender,
address token,
uint256 newPriceX96,
uint48 fallbackUpdatedAt
);
/// @notice Emitted when validPeriod updates
/// @param origin Origin of the transaction (tx.origin)
/// @param sender Sender of the call (msg.sender)
/// @param validPeriod Current valid period
event ValidPeriodUpdated(address indexed origin, address indexed sender, uint256 validPeriod);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: CC0-1.0
pragma solidity ^0.8.0;
interface IAggregatorV3 {
function decimals() external view returns (uint8);
function description() external view returns (string memory);
function version() external view returns (uint256);
// getRoundData and latestRoundData should both raise "No data present"
// if they do not have data to report, instead of returning unset values
// which could be misinterpreted as actual reported values.
function getRoundData(uint80 _roundId)
external
view
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
);
function latestRoundData()
external
view
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
);
}
// SPDX-License-Identifier: CC0-1.0
pragma solidity ^0.8.0;
interface IOracle {
/// @notice Oracle price for token.
/// @param token Reference to token
/// @return success True if call to an external oracle was successful, false otherwise
/// @return priceX96 Price that satisfy token
function price(address token) external view returns (bool success, uint256 priceX96);
/// @notice Returns if an oracle was approved for a token
/// @param token A given token address
/// @return bool True if an oracle was approved for a token, else - false
function hasOracle(address token) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 amount) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}