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Offchain aggregator#

IXLayerOffchainAggregator#

A dedicated price feed for an asset pair, which comes with batch viewing capabilities._createMdxContent

XLayerOffchainAggregator#

  • Includes batch view functions
  • Includes IAggregator, IConfig and IExternalValidator which are listed below
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IXLayerOffchainAggregator is
    IAggregator,
    IExternalValidator,
    IConfig
{
    //Batch view related queries
    function fetchRange(
        uint80 startId,
        uint80 endId
    )
        external
        view
        returns (
            uint80[] memory roundId,
            int256[] memory answer,
            uint256[] memory startedAt,
            uint256[] memory updatedAt,
            uint80[] memory answeredInRound
        );

    function fetchLastEntries(
        uint80 count
    )
        external
        view
        returns (
            uint80[] memory roundId,
            int256[] memory answer,
            uint256[] memory startedAt,
            uint256[] memory updatedAt,
            uint80[] memory answeredInRound
        );
}
FunctionPermissionDescription
fetchRange-1. Provide a range of entries in ascending order based on startId and endId
2. Results include both startId and endId.
fetchLastEntries-1. Provides a range of entries in ascending order based on count.
2. Total number of entries returned will be counted, and includes the last entry.

IAggregator#

This is a Chainlink compatible interface for retrieving asset prices on contracts. It supports both AggregatorV3 (latest) and AggregatorV2 (deprecated).

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IAggregator {
    event AnswerUpdated(
        int256 indexed current,
        uint256 indexed roundId,
        uint256 updatedAt
    );
    event NewRound(
        uint256 indexed roundId,
        address indexed startedBy,
        uint256 startedAt
    );

    struct Transmission {
        int192 answer; // 192 bits ought to be enough for anyone
        uint64 timestamp;
    }

    struct HotVars {
        bytes16 latestConfigDigest; //rewrote as bytes16(keccak256(abi.encode(implAddr, description, version, min, max)))
        uint80 latestAggregatorRoundId;
    }
    
    // AggregatorV3Interface
    function decimals() external view returns (uint8);

    function description() external view returns (string memory);

    function version() external view returns (uint256);

    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
        );

    // AggregatorV2Interface
    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);
}
FunctionPermissionDescription
decimals-Number of decimals present in the response
description-Description of the underlying aggregator
version-Version number of the aggregator. Increases each time the contract is upgraded
getRoundData-Retrieves data for a specific roundId. Reverts if it does not fall in the range of the current aggregator,
latestRoundData-Retrieves data from the latest round.
latestAnswer-Retrieves price from latest round.
latestTimestamp-Retrieves timestamp from latest round.
latestRound-Retrieves latest roundid.
getAnswer-Retrieves price for a specific roundId. Reverts if it does not fall in the range of the current aggregator.
getTimestamp-Retrieves price for a specific roundId. Reverts if it does not fall in the range of the current aggregator.

IConfig#

It retrieves the latest config details, and updates bounds of minimum and maximum price updates.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IConfig {
    event UpdatedConfig(uint256 indexed version, bytes16 configDigest);

    function updateLowerBound(int192 newMinAnswer) external;

    function updateUpperBound(int192 newMaxAnswer) external;

    function latestConfigDetails() external view returns (bytes16 configDigest);
}
FunctionPermissionDescription
updateLowerBoundOwnerUpdates the minimum price that can be transmitted to this aggregator. If valid, will trigger an update for configdigest and emit UpdatedConfig.
updateUpperBoundOwnerUpdates the maximum price that can be transmitted to this aggregator. If valid, will trigger an update for configdigest and emit UpdatedConfig.
latestConfigDetails-Retrieves the current configdigest

IExternalValidator#

This is used for updating the external validator configuration, which will be triggered as a callback during price update.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IExternalValidator {
    struct ValidatorConfig {
        AggregatorValidatorInterface validator;
        uint32 gasLimit;
    }

    event ValidatorConfigSet(
        AggregatorValidatorInterface indexed previousValidator,
        uint32 previousGasLimit,
        AggregatorValidatorInterface indexed currentValidator,
        uint32 currentGasLimit
    );

    function validatorConfig()
        external
        view
        returns (AggregatorValidatorInterface validator, uint32 gasLimit);

    function setValidatorConfig(
        AggregatorValidatorInterface _newValidator,
        uint32 _newGasLimit
    ) external;
}

interface AggregatorValidatorInterface {
    function validate(
        uint256 previousRoundId,
        int256 previousAnswer,
        uint256 currentRoundId,
        int256 currentAnswer
    ) external returns (bool);
}
FunctionPermissionDescription
validatorConfig-Retrieves the current validator confi
setValidatorConfigOwner1. Updates validator config if Validator address changes OR Gas allocated is changed.

2. Emits ValidatorConfigSet if update is successful.
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