GaugeV1

Overview

GaugeV1 is an upgradeable contract used to manage reward distributions for a particular pool or strategy in the EYWA ecosystem. The contract primarily integrates with the Escrow Vote Manager (s_escrowVoteManager) to authorize reward notifications and uses a Distribution Creator (DISTRIBUTION_CREATOR) for executing reward distribution campaigns.

Key features include:

• Upgradeable (UUPS Pattern): The contract can be updated while preserving state.

• Owner-Based Access Control: Critical functions (like upgrading the contract and updating campaign parameters) are restricted to the owner.

• Reward Notification: The notifyRewardAmount function can only be invoked by the authorized escrow vote manager, ensuring a controlled flow of rewards.

• Campaign Parameters: The gauge uses dynamic campaign parameters (s_campaignParameters) to manage reward distribution schedules and amounts, which can be updated by the owner if needed.

By implementing IGaugeV1, GaugeV1 provides a standardized interface for initializing, updating campaign parameters, and receiving new reward amounts within the EYWA ecosystem.

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Inherited Contracts and Interfaces

• UUPSUpgradeable (OpenZeppelin): Enables upgradeability under the UUPS (Universal Upgradeable Proxy Standard) pattern, restricted to the contract owner.

• OwnableUpgradeable (OpenZeppelin): Provides ownership logic, limiting certain state changes (e.g., upgrading, updating parameters) to the contract owner.

• IGaugeV1: Interface defining core functions (e.g., initialize, updateCampaignParameters, notifyRewardAmount) and events (RewardNotified, CampaignParametersUpdated) for the gauge contract.

Additional External References:

• SafeERC20, IERC20 (OpenZeppelin): Library and interface for safe ERC20 token transfers.

• IEscrowVoteManagerV1: Tracks and authorizes reward notifications, ensuring that only the designated manager can call notifyRewardAmount.

• IDistributionCreator: Contract on Arbitrum that actually creates or schedules distribution campaigns (Merkl distributions).

  • The contract uses DISTRIBUTION_CREATOR with a known address (0x8BB4C975Ff3c250e0ceEA271728547f3802B36Fd) on Arbitrum.

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Constants

uint256 public constant EPOCH_DURATION = 1 weeks;
IDistributionCreator public constant DISTRIBUTION_CREATOR = IDistributionCreator(0x8BB4C975Ff3c250e0ceEA271728547f3802B36Fd);

• EPOCH_DURATION: The duration of an epoch (1 week). Used to align reward distribution campaigns with discrete time intervals.

• DISTRIBUTION_CREATOR: The address of the Merkl distribution contract on Arbitrum. This contract is responsible for orchestrating reward distributions once campaigns are created.

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State Variables

• s_escrowVoteManager (address) Address of the escrow vote manager contract, which is authorized to call notifyRewardAmount.

• s_eywa (address) The EYWA token address used for rewards distribution.

• s_campaignParameters (IDistributionCreator.CampaignParameters) Holds the current campaign parameters for distributing rewards. These parameters include data like amount, duration, start timestamp, and distribution logic, which can be updated by the owner.

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Constructor

constructor() {
    _disableInitializers();
}

• Description: Disables contract initializers to prevent multiple initializations. Enforces that initialize can be called only once in a UUPS upgradeable context.

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External Functions

initialize(...)

function initialize(
    address owner_,
    address escrowVoteManager_,
    address eywa_,
    IDistributionCreator.CampaignParameters calldata campaignParameters_
) 
    external
    initializer

• Description:

  • Initializes the gauge contract by setting the owner, escrow vote manager, EYWA token address, and the initial campaign parameters for rewards.

  • Can only be called once, marked by the initializer modifier from OpenZeppelin upgradeable patterns.

• Parameters:

  • owner_: The address designated as the contract owner.

  • escrowVoteManager_: The address of the escrow vote manager, authorized to call notifyRewardAmount.

  • eywa_: The address of the EYWA token used for distributing rewards.

  • campaignParameters_: Initial set of campaign parameters (amount, duration, schedule, etc.) used in distribution campaigns.

• Effects:

  • Calls __UUPSUpgradeable_init() and __Ownable_init(owner_) to set up UUPS upgrade and ownership.

  • Assigns s_escrowVoteManager and s_eywa references.

  • Stores s_campaignParameters from input.

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updateCampaignParameters(...)

function updateCampaignParameters(
    IDistributionCreator.CampaignParameters calldata newCampaignParameters_
) 
    external 
    onlyOwner

• Description:

  • Allows the contract owner to update the gauge’s campaign parameters.

  • The newly provided parameters (newCampaignParameters_) overwrite the existing ones in s_campaignParameters.

• Parameters:

  • newCampaignParameters_: The updated distribution parameters (e.g., new schedule or amounts) for this gauge.

• Events:

  • Emits CampaignParametersUpdated(address(this), oldCampaignParameters, newCampaignParameters_) to log the changes.

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notifyRewardAmount(uint256 amount_)

function notifyRewardAmount(uint256 amount_) external

• Description:

  • Notifies the gauge of a newly available amount_ of EYWA tokens to be distributed as rewards.

  • Can only be called by s_escrowVoteManager.

  • The function transfers amount_ from the caller to this gauge, checks if the resulting balance is sufficient to meet the minimum distribution threshold, and if so, triggers the distribution campaign via DISTRIBUTION_CREATOR.createCampaign(...).

• Parameters:

  • amount_: The amount of EYWA tokens to be added for distribution.

• Checks & Logic:

  1. Verifies msg.sender == s_escrowVoteManager, otherwise reverts with UnauthorizedCaller().

  2. Transfers amount_ of EYWA from the caller to the contract.

  3. If the new balance (multiplied by 1 hour / EPOCH_DURATION) meets the rewardTokenMinAmounts(...) requirement of DISTRIBUTION_CREATOR, the contract approves DISTRIBUTION_CREATOR to spend its entire balance and initiates a campaign:

     • Sets m_campaignParameters.amount to the new gauge balance.

     • Sets startTimestamp = uint32(block.timestamp).

     • Sets duration = uint32(EPOCH_DURATION) (one week).

     • Calls createCampaign(...) on DISTRIBUTION_CREATOR.

  4. Emits RewardNotified(amount_).

• Events:

  • RewardNotified(amount_) logs the newly notified reward amount.

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Internal and Private Functions

_authorizeUpgrade(address)

function _authorizeUpgrade(address) internal override onlyOwner

• Description:

  • Ensures that only the contract owner can authorize upgrades.

  • Enforced by the UUPSUpgradeable pattern.

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Events

1. RewardNotified(uint256 indexed amount)

   • Emitted when new rewards are notified to the gauge, indicating the total tokens added.

2. CampaignParametersUpdated( address indexed gauge, IDistributionCreator.CampaignParameters oldCampaignParameters, IDistributionCreator.CampaignParameters newCampaignParameters )

   • Logged when the owner updates the gauge’s distribution campaign parameters.

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Errors

• UnauthorizedCaller()

  • Thrown if a function restricted to s_escrowVoteManager or onlyOwner is called by an unauthorized address.

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Summary

GaugeV1 is an upgradeable contract that manages reward distributions for a specific pool or strategy within the EYWA ecosystem. By connecting to an Escrow Vote Manager, it ensures only authorized parties can add new rewards (notifyRewardAmount). Through DistributionCreator on Arbitrum, it transforms these rewards into time-bound distribution campaigns. The contract owner can update campaign parameters if needed, while all major functionalities (initialization, upgrade, parameter updates) remain protected by ownership and authorized checks.