Copy
9contract Owned {
10    address public owner;
11    address private pendingOwner;
12
13    event OwnershipTransferRequested(address indexed from, address indexed to);
14    event OwnershipTransferred(address indexed from, address indexed to);
15
16    constructor() {
17        owner = msg.sender;
18    }
19
20    /**
21     * @dev Allows an owner to begin transferring ownership to a new address,
22     * pending.
23     */
24    function transferOwnership(address _to) external onlyOwner {
25        pendingOwner = _to;
26
27        emit OwnershipTransferRequested(owner, _to);
28    }
29
30    /**
31     * @dev Allows an ownership transfer to be completed by the recipient.
32     */
33    function acceptOwnership() external {
34        require(msg.sender == pendingOwner, "Must be proposed owner");
35
36        address oldOwner = owner;
37        owner = msg.sender;
38        pendingOwner = address(0);
39
40        emit OwnershipTransferred(oldOwner, msg.sender);
41    }
42
43    /**
44     * @dev Reverts if called by anyone other than the contract owner.
45     */
46    modifier onlyOwner() {
47        require(msg.sender == owner, "Only callable by owner");
48        _;
49    }
50}
51
52interface AggregatorInterface {
53    function latestAnswer() external view returns (int256);
54
55    function latestTimestamp() external view returns (uint256);
56
57    function latestRound() external view returns (uint256);
58
59    function getAnswer(uint256 roundId) external view returns (int256);
60
61    function getTimestamp(uint256 roundId) external view returns (uint256);
62
63    event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);
64    event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
65}
66
67interface AggregatorV3Interface {
68    function decimals() external view returns (uint8);
69
70    function description() external view returns (string memory);
71
72    function version() external view returns (uint256);
73
74    // getRoundData and latestRoundData should both raise "No data present"
75    // if they do not have data to report, instead of returning unset values
76    // which could be misinterpreted as actual reported values.
77    function getRoundData(
78        uint80 _roundId
79    )
80        external
81        view
82        returns (
83            uint80 roundId,
84            int256 answer,
85            uint256 startedAt,
86            uint256 updatedAt,
87            uint80 answeredInRound
88        );
89
90    function latestRoundData()
91        external
92        view
93        returns (
94            uint80 roundId,
95            int256 answer,
96            uint256 startedAt,
97            uint256 updatedAt,
98            uint80 answeredInRound
99        );
100}
101
102interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface {}
103
104/**
105 * @title External Access Controlled Aggregator Proxy
106 * @notice A trusted proxy for updating where current answers are read from
107 * @notice This contract provides a consistent address for the
108 * Aggregator and AggregatorV3Interface but delegates where it reads from to the owner, who is
109 * trusted to update it.
110 * @notice Only access enabled addresses are allowed to access getters for
111 * aggregated answers and round information.
112 */
113contract UsdUsdOracle is AggregatorV2V3Interface, Owned {