Chainlink oracle
Chainlink Data Feeds are the quickest way to connect smar contracts to the real-world data such as asset prices. One use for data feeds is to retrieve the latest pricing data of an asset in a single call and use that data either on-chain in a smart contract.
/**
*Submitted for verification at BscScan.com on 2020-11-09
*/
pragma solidity 0.6.6;
/**
* @title The Owned contract
* @notice A contract with helpers for basic contract ownership.
*/
contract Owned {
address public owner;
address private pendingOwner;
event OwnershipTransferRequested(
address indexed from,
address indexed to
);
event OwnershipTransferred(
address indexed from,
address indexed to
);
constructor() public {
owner = msg.sender;
}
/**
* @dev Allows an owner to begin transferring ownership to a new address,
* pending.
*/
function transferOwnership(address _to)
external
onlyOwner()
{
pendingOwner = _to;
emit OwnershipTransferRequested(owner, _to);
}
/**
* @dev Allows an ownership transfer to be completed by the recipient.
*/
function acceptOwnership()
external
{
require(msg.sender == pendingOwner, "Must be proposed owner");
address oldOwner = owner;
owner = msg.sender;
pendingOwner = address(0);
emit OwnershipTransferred(oldOwner, msg.sender);
}
/**
* @dev Reverts if called by anyone other than the contract owner.
*/
modifier onlyOwner() {
require(msg.sender == owner, "Only callable by owner");
_;
}
}
interface AggregatorInterface {
function latestAnswer() external view returns (int256);
function latestTimestamp() external view returns (uint256);
function latestRound() external view returns (uint256);
function getAnswer(uint256 roundId) external view returns (int256);
function getTimestamp(uint256 roundId) external view returns (uint256);
event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);
event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
}
interface AggregatorV3Interface {
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
);
}
interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface
{
}
/**
* @title A trusted proxy for updating where current answers are read from
* @notice This contract provides a consistent address for the
* CurrentAnwerInterface but delegates where it reads from to the owner, who is
* trusted to update it.
*/
contract AggregatorProxy is AggregatorV2V3Interface, Owned {
struct Phase {
uint16 id;
AggregatorV2V3Interface aggregator;
}
Phase private currentPhase;
AggregatorV2V3Interface public proposedAggregator;
mapping(uint16 => AggregatorV2V3Interface) public phaseAggregators;
uint256 constant private PHASE_OFFSET = 64;
uint256 constant private PHASE_SIZE = 16;
uint256 constant private MAX_ID = 2**(PHASE_OFFSET+PHASE_SIZE) - 1;
constructor(address _aggregator) public Owned() {
setAggregator(_aggregator);
}
/**
* @notice Reads the current answer from aggregator delegated to.
*
* @dev #[deprecated] Use latestRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended latestRoundData
* instead which includes better verification information.
*/
function latestAnswer()
public
view
virtual
override
returns (int256 answer)
{
return currentPhase.aggregator.latestAnswer();
}
/**
* @notice Reads the last updated height from aggregator delegated to.
*
* @dev #[deprecated] Use latestRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended latestRoundData
* instead which includes better verification information.
*/
function latestTimestamp()
public
view
virtual
override
returns (uint256 updatedAt)
{
return currentPhase.aggregator.latestTimestamp();
}
/**
* @notice get past rounds answers
* @param _roundId the answer number to retrieve the answer for
*
* @dev #[deprecated] Use getRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended getRoundData
* instead which includes better verification information.
*/
function getAnswer(uint256 _roundId)
public
view
virtual
override
returns (int256 answer)
{
if (_roundId > MAX_ID) return 0;
(uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
AggregatorV2V3Interface aggregator = phaseAggregators[phaseId];
if (address(aggregator) == address(0)) return 0;
return aggregator.getAnswer(aggregatorRoundId);
}
/**
* @notice get block timestamp when an answer was last updated
* @param _roundId the answer number to retrieve the updated timestamp for
*
* @dev #[deprecated] Use getRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended getRoundData
* instead which includes better verification information.
*/
function getTimestamp(uint256 _roundId)
public
view
virtual
override
returns (uint256 updatedAt)
{
if (_roundId > MAX_ID) return 0;
(uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
AggregatorV2V3Interface aggregator = phaseAggregators[phaseId];
if (address(aggregator) == address(0)) return 0;
return aggregator.getTimestamp(aggregatorRoundId);
}
/**
* @notice get the latest completed round where the answer was updated. This
* ID includes the proxy's phase, to make sure round IDs increase even when
* switching to a newly deployed aggregator.
*
* @dev #[deprecated] Use latestRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended latestRoundData
* instead which includes better verification information.
*/
function latestRound()
public
view
virtual
override
returns (uint256 roundId)
{
Phase memory phase = currentPhase; // cache storage reads
return addPhase(phase.id, uint64(phase.aggregator.latestRound()));
}
/**
* @notice get data about a round. Consumers are encouraged to check
* that they're receiving fresh data by inspecting the updatedAt and
* answeredInRound return values.
* Note that different underlying implementations of AggregatorV3Interface
* have slightly different semantics for some of the return values. Consumers
* should determine what implementations they expect to receive
* data from and validate that they can properly handle return data from all
* of them.
* @param _roundId the requested round ID as presented through the proxy, this
* is made up of the aggregator's round ID with the phase ID encoded in the
* two highest order bytes
* @return roundId is the round ID from the aggregator for which the data was
* retrieved combined with an phase to ensure that round IDs get larger as
* time moves forward.
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @dev Note that answer and updatedAt may change between queries.
*/
function getRoundData(uint80 _roundId)
public
view
virtual
override
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
(uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
(
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 ansIn
) = phaseAggregators[phaseId].getRoundData(aggregatorRoundId);
return addPhaseIds(roundId, answer, startedAt, updatedAt, ansIn, phaseId);
}
/**
* @notice get data about the latest round. Consumers are encouraged to check
* that they're receiving fresh data by inspecting the updatedAt and
* answeredInRound return values.
* Note that different underlying implementations of AggregatorV3Interface
* have slightly different semantics for some of the return values. Consumers
* should determine what implementations they expect to receive
* data from and validate that they can properly handle return data from all
* of them.
* @return roundId is the round ID from the aggregator for which the data was
* retrieved combined with an phase to ensure that round IDs get larger as
* time moves forward.
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @dev Note that answer and updatedAt may change between queries.
*/
function latestRoundData()
public
view
virtual
override
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
Phase memory current = currentPhase; // cache storage reads
(
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 ansIn
) = current.aggregator.latestRoundData();
return addPhaseIds(roundId, answer, startedAt, updatedAt, ansIn, current.id);
}
/**
* @notice Used if an aggregator contract has been proposed.
* @param _roundId the round ID to retrieve the round data for
* @return roundId is the round ID for which data was retrieved
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
*/
function proposedGetRoundData(uint80 _roundId)
public
view
virtual
hasProposal()
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
return proposedAggregator.getRoundData(_roundId);
}
/**
* @notice Used if an aggregator contract has been proposed.
* @return roundId is the round ID for which data was retrieved
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
*/
function proposedLatestRoundData()
public
view
virtual
hasProposal()
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
return proposedAggregator.latestRoundData();
}
/**
* @notice returns the current phase's aggregator address.
*/
function aggregator()
external
view
returns (address)
{
return address(currentPhase.aggregator);
}
/**
* @notice returns the current phase's ID.
*/
function phaseId()
external
view
returns (uint16)
{
return currentPhase.id;
}
/**
* @notice represents the number of decimals the aggregator responses represent.
*/
function decimals()
external
view
override
returns (uint8)
{
return currentPhase.aggregator.decimals();
}
/**
* @notice the version number representing the type of aggregator the proxy
* points to.
*/
function version()
external
view
override
returns (uint256)
{
return currentPhase.aggregator.version();
}
/**
* @notice returns the description of the aggregator the proxy points to.
*/
function description()
external
view
override
returns (string memory)
{
return currentPhase.aggregator.description();
}
/**
* @notice Allows the owner to propose a new address for the aggregator
* @param _aggregator The new address for the aggregator contract
*/
function proposeAggregator(address _aggregator)
external
onlyOwner()
{
proposedAggregator = AggregatorV2V3Interface(_aggregator);
}
/**
* @notice Allows the owner to confirm and change the address
* to the proposed aggregator
* @dev Reverts if the given address doesn't match what was previously
* proposed
* @param _aggregator The new address for the aggregator contract
*/
function confirmAggregator(address _aggregator)
external
onlyOwner()
{
require(_aggregator == address(proposedAggregator), "Invalid proposed aggregator");
delete proposedAggregator;
setAggregator(_aggregator);
}
/*
* Internal
*/
function setAggregator(address _aggregator)
internal
{
uint16 id = currentPhase.id + 1;
currentPhase = Phase(id, AggregatorV2V3Interface(_aggregator));
phaseAggregators[id] = AggregatorV2V3Interface(_aggregator);
}
function addPhase(
uint16 _phase,
uint64 _originalId
)
internal
view
returns (uint80)
{
return uint80(uint256(_phase) << PHASE_OFFSET | _originalId);
}
function parseIds(
uint256 _roundId
)
internal
view
returns (uint16, uint64)
{
uint16 phaseId = uint16(_roundId >> PHASE_OFFSET);
uint64 aggregatorRoundId = uint64(_roundId);
return (phaseId, aggregatorRoundId);
}
function addPhaseIds(
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound,
uint16 phaseId
)
internal
view
returns (uint80, int256, uint256, uint256, uint80)
{
return (
addPhase(phaseId, uint64(roundId)),
answer,
startedAt,
updatedAt,
addPhase(phaseId, uint64(answeredInRound))
);
}
/*
* Modifiers
*/
modifier hasProposal() {
require(address(proposedAggregator) != address(0), "No proposed aggregator present");
_;
}
}
interface AccessControllerInterface {
function hasAccess(address user, bytes calldata data) external view returns (bool);
}
/**
* @title External Access Controlled Aggregator Proxy
* @notice A trusted proxy for updating where current answers are read from
* @notice This contract provides a consistent address for the
* Aggregator and AggregatorV3Interface but delegates where it reads from to the owner, who is
* trusted to update it.
* @notice Only access enabled addresses are allowed to access getters for
* aggregated answers and round information.
*/
contract EACAggregatorProxy is AggregatorProxy {
AccessControllerInterface public accessController;
constructor(
address _aggregator,
address _accessController
)
public
AggregatorProxy(_aggregator)
{
setController(_accessController);
}
/**
* @notice Allows the owner to update the accessController contract address.
* @param _accessController The new address for the accessController contract
*/
function setController(address _accessController)
public
onlyOwner()
{
accessController = AccessControllerInterface(_accessController);
}
/**
* @notice Reads the current answer from aggregator delegated to.
* @dev overridden function to add the checkAccess() modifier
*
* @dev #[deprecated] Use latestRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended latestRoundData
* instead which includes better verification information.
*/
function latestAnswer()
public
view
override
checkAccess()
returns (int256)
{
return super.latestAnswer();
}
/**
* @notice get the latest completed round where the answer was updated. This
* ID includes the proxy's phase, to make sure round IDs increase even when
* switching to a newly deployed aggregator.
*
* @dev #[deprecated] Use latestRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended latestRoundData
* instead which includes better verification information.
*/
function latestTimestamp()
public
view
override
checkAccess()
returns (uint256)
{
return super.latestTimestamp();
}
/**
* @notice get past rounds answers
* @param _roundId the answer number to retrieve the answer for
* @dev overridden function to add the checkAccess() modifier
*
* @dev #[deprecated] Use getRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended getRoundData
* instead which includes better verification information.
*/
function getAnswer(uint256 _roundId)
public
view
override
checkAccess()
returns (int256)
{
return super.getAnswer(_roundId);
}
/**
* @notice get block timestamp when an answer was last updated
* @param _roundId the answer number to retrieve the updated timestamp for
* @dev overridden function to add the checkAccess() modifier
*
* @dev #[deprecated] Use getRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended getRoundData
* instead which includes better verification information.
*/
function getTimestamp(uint256 _roundId)
public
view
override
checkAccess()
returns (uint256)
{
return super.getTimestamp(_roundId);
}
/**
* @notice get the latest completed round where the answer was updated
* @dev overridden function to add the checkAccess() modifier
*
* @dev #[deprecated] Use latestRoundData instead. This does not error if no
* answer has been reached, it will simply return 0. Either wait to point to
* an already answered Aggregator or use the recommended latestRoundData
* instead which includes better verification information.
*/
function latestRound()
public
view
override
checkAccess()
returns (uint256)
{
return super.latestRound();
}
/**
* @notice get data about a round. Consumers are encouraged to check
* that they're receiving fresh data by inspecting the updatedAt and
* answeredInRound return values.
* Note that different underlying implementations of AggregatorV3Interface
* have slightly different semantics for some of the return values. Consumers
* should determine what implementations they expect to receive
* data from and validate that they can properly handle return data from all
* of them.
* @param _roundId the round ID to retrieve the round data for
* @return roundId is the round ID from the aggregator for which the data was
* retrieved combined with a phase to ensure that round IDs get larger as
* time moves forward.
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @dev Note that answer and updatedAt may change between queries.
*/
function getRoundData(uint80 _roundId)
public
view
checkAccess()
override
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
return super.getRoundData(_roundId);
}
/**
* @notice get data about the latest round. Consumers are encouraged to check
* that they're receiving fresh data by inspecting the updatedAt and
* answeredInRound return values.
* Note that different underlying implementations of AggregatorV3Interface
* have slightly different semantics for some of the return values. Consumers
* should determine what implementations they expect to receive
* data from and validate that they can properly handle return data from all
* of them.
* @return roundId is the round ID from the aggregator for which the data was
* retrieved combined with a phase to ensure that round IDs get larger as
* time moves forward.
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @dev Note that answer and updatedAt may change between queries.
*/
function latestRoundData()
public
view
checkAccess()
override
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
return super.latestRoundData();
}
/**
* @notice Used if an aggregator contract has been proposed.
* @param _roundId the round ID to retrieve the round data for
* @return roundId is the round ID for which data was retrieved
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
*/
function proposedGetRoundData(uint80 _roundId)
public
view
checkAccess()
hasProposal()
override
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
return super.proposedGetRoundData(_roundId);
}
/**
* @notice Used if an aggregator contract has been proposed.
* @return roundId is the round ID for which data was retrieved
* @return answer is the answer for the given round
* @return startedAt is the timestamp when the round was started.
* (Only some AggregatorV3Interface implementations return meaningful values)
* @return updatedAt is the timestamp when the round last was updated (i.e.
* answer was last computed)
* @return answeredInRound is the round ID of the round in which the answer
* was computed.
*/
function proposedLatestRoundData()
public
view
checkAccess()
hasProposal()
override
returns (
uint80 roundId,
int256 answer,
uint256 startedAt,
uint256 updatedAt,
uint80 answeredInRound
)
{
return super.proposedLatestRoundData();
}
/**
* @dev reverts if the caller does not have access by the accessController
* contract or is the contract itself.
*/
modifier checkAccess() {
AccessControllerInterface ac = accessController;
require(address(ac) == address(0) || ac.hasAccess(msg.sender, msg.data), "No access");
_;
}
}Last updated
