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Energy Rental

Introduction

All transactions on JustLend DAO require Energy, which can only be acquired through staking or burning TRX. This process involves high costs and lengthy procedures. In response, JustLend DAO introduces the Energy Rental service, allowing users to rent Energy at a significantly reduced price compared to staking or burning TRX. The contract EnergyRental used to set up the Energy Rental service.

Query Interface

Rental Order Information

View the information of an rental order.

function rentals (address renter, address receiver, uint256 resourceType) public view returns (RentalInfo)

struct RentalInfo {
    uint256 amount;
    uint256 securityDeposit;
    uint256 rentIndex;
}

  • Parameter description:

    • renter: order payer;

    • receiver: the resource receiver of this rental;

    • resourceType: resource type, 0: bandwidth; 1: energy.

  • Returns:

    • amount: order resources corresponding to the amount of TRX (delegated TRX amount);

    • securityDeposit: order deposit, not updated to current;

    • rentIndex: order's global index at the time of its last update.

Current Rental Order Information (updated to current)

View the information of an rental order, with the returned data updated to current.

function getRentInfo (address renter, address receiver, uint256 resourceType) external view returns (uint256, uint256)

  • Parameter description:

    • renter: order payer;

    • receiver: the resource receiver of this rental;

    • resourceType: resource type, 0: bandwidth; 1: energy.

  • Returns:

    • securityDeposit: order deposit, updated to current；

    • rentIndex: real-time global index of the order at the time of query.

Bad Debt

If the user's rent is greater than securityDeposit, a bad debt will be generated. This field will be updated when repayment or liquidation occurs.

function badDebt() view external returns (uint256)

  • Parameter description: N/A;

  • Returns: the amount of bad debt in TRX, minimum unit.

Covered Bad Debt

Bad debts will be filled when the collectible rewards (_settleIncome) are updated or the repayBadDebt function is triggered.

function badDebtCovered() view external returns (uint256)

  • Parameter description: N/A;

  • Returns: the amount of cumulative bad debt has been filled in TRX , minimum unit.

Bad Debt To Be Covered

The amount of bad debt that has not been processed. In fact, this value is equal to the amount of badDebt minus badDebtCovered.

function badDebtGap() view external returns (uint256)

  • Parameter description: N/A;

  • Returns: the amount of bad debt to be covered in TRX, minimum unit.

Total Rent Income

Rental income from renting energy.

function totalRent() view external returns (uint256)

  • Parameter description: N/A;

  • Returns: the amount of total rental income.

Claimed Rent Income

The STRX contract can extract the income through the claimRental function, which records the accumulated income that has been extracted.

function rentClaimed() view external returns (uint256)

  • Parameter description: N/A;

  • Returns: the amount of accumulate income that has been extracted.

Liquidation Rate

The liquidateRate is used during liquidation. If the price fluctuates greatly, it will be diluted for 6 hours. Rapidly raised prices will not take effect immediately during the liquidation process.

function _liquidateRate(uint256 resourceType) view external returns (uint256)

  • Parameter description:

    • resourceType: resource type, 0: bandwidth; 1: energy.

  • Returns: current liquidation rate.

Rental Rate

Get the latest rental rate. when the amount is passed as 0, it returns the current tental rate. When the amount is greater than 0, for example, 100, it returns the rental rate after the energy changes by 100.

function _rentalRate(uint256 amount, uint256 resourceType) view external returns (uint256)

  • Parameter description:

    • amount: order resources corresponding to the amount of TRX;

    • resourceType: resource type, 0: bandwidth; 1: energy.

  • Returns: current rental rate.

Write Interface

Rent Resources

Rent resources, allow amount = 0 (extension only) or msg.value = 0 (no new deposit), both are 0 is not allowed.

function rentResource (address receiver, uint256 amount, uint256 resourceType) external payable

  • Parameter description:

    • receiver: the resource receiver of this rental. Not allowed to be a contract or an unactivated account;

    • amount: the rent resource corresponding to the amount of TRX (delegated TRX amount), the minimum unit, if the amount is not 0 (renewal only), it must be greater than 1 TRX;

    • resourceType: resource type, 0: bandwidth; 1: energy;

    • msg.sender: the payer for this rental;

    • msg.value: new deposit of this time.

  • Returns: None, revert on failure.

📅 Event

RentResource (address indexed renter, address indexed receiver, uint256 addedAmount, uint256 resourceType, uint256 addedSecurityDeposit, uint256 amount)

  • Emits when renting occurs.

    • renter: order payer;

    • receiver: the resource receiver of this rental;

    • addedAmount: the TRX amount (minimum unit) of the newly-rent resource;

    • resourceType: resource type, 0: bandwidth; 1: energy;

    • addedSecurityDeposit: the added deposit amount;

    • amount: the total amount of rental resources in the order after renting.

Return Resources (called by payer)

Return resources. Return resources in the order (msg.sender, receiver, resourceType). When the remaining deposit is insufficient, all resources will be forcibly emptied, and the remaining deposit will be returned to the order payer.

function returnResource (address receiver, uint256 amount, uint256 resourceType) external returns (uint256)

  • Parameter description:

    • receiver: the resource receiver of this rental;

    • amount: rent resource corresponding to the amount of TRX (delegated TRX amount), the minimum unit;

    • resourceType: resource type, 0: bandwidth; 1: energy;

    • msg.sender: resource receiver.

  • Returns: the amount of the deposit returned in this operation. 0 for a partial return.

📅 Event

ReturnResource( address indexed renter, address indexed receiver, uint256 subedAmount, uint256 resourceType, uint256 usageRental, uint256 subedSecurityDeposit, uint256 amount)

  • Emits when resources are returned.

    • renter: order payer;

    • receiver: the resource receiver of this rental;

    • subedAmount: the amount of TRX (minimum unit) for returned resources;

    • resourceType: resource type, 0: bandwidth; 1: energy;

    • usageRental: the cost of recovery for the used resources in the returned resources;

    • subedSecurityDeposit: the refunded deposit amount (0 for partial returns);

    • amount: the remaining amount of rental resources after returning resources.

Return resources (called by receiver)

Return resources. Return resources in the order (renter, msg.sender, resourceType). When the remaining deposit is insufficient, all resources will be forcibly emptied, and the remaining deposit will be returned to the order payer.

function returnResourceByReceiver (address renter, uint256 amount, uint256 resourceType) external returns (uint256)

  • Parameter description:

    • renter: order payer;

    • amount: rent resource corresponding to the amount of TRX (delegated TRX amount), the minimum unit;

    • resourceType: resource type, 0: bandwidth; 1: energy;

    • msg.sender: resource receiver;

  • Returns: the amount of the deposit returned in this operation. 0 for partial return.

Liquidate

When the order deposit is insufficient, the liquidator can liquidate the order, and the liquidator will get the liquidation reward. If there is any remaining deposit, it will be returned to the order payer.

function liquidate (address renter, address receiver, uint256 resourceType) external returns (uint256)

  • Parameter description:

    • renter: order payer;

    • receiver: the resource receiver of this rental;

    • resourceType: resource type, 0: bandwidth; 1: energy;

    • msg.sender: liquidator;

  • Returns: Liquidation reward in this operation.

📅 Event

Liquidate( address indexed liquidator, address indexed renter, address indexed receiver, uint256 amount, uint256 resourceType, uint256 usageRental, uint256 liquidateFee, uint256 sendBack)

  • Emits when liquidation occurs.

    • liquidator: the person liquidate the order;

    • renter: order payer;

    • receiver: the resource receiver of this rental;

    • amount: rent resource corresponding to the amount of TRX (delegated TRX amount), the minimum unit;

    • resourceType: resource type, 0: bandwidth; 1: energy;

    • usageRental: the fee for the recovery time of the order resource usage;

    • liquidateFee: the liquidation reward received by the liquidator;

    • sendBack: the remaining deposit received by the payer.

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