AccountingEngine

Git Source

Inherits: Authorizable, Modifiable, Disableable, IAccountingEngine

This contract is responsible for handling protocol surplus and debt

It allows the system to auction surplus and debt, as well as transfer surplus

This is a system contract, therefore it is not meant to be used by users directly

State Variables

safeEngine

Address of the SAFEEngine contract

ISAFEEngine public safeEngine;

surplusAuctionHouse

Address of the SurplusAuctionHouse contract

ISurplusAuctionHouse public surplusAuctionHouse;

debtAuctionHouse

Address of the DebtAuctionHouse contract

IDebtAuctionHouse public debtAuctionHouse;

postSettlementSurplusDrain

The post settlement surplus drain is used to transfer remaining surplus after settlement is triggered

Usually the SettlementSurplusAuctioneer contract

address public postSettlementSurplusDrain;

extraSurplusReceiver

The extra surplus receiver is used to transfer surplus if is not being auctioned

address public extraSurplusReceiver;

_params

Getter for the unpacked contract parameters struct

AccountingEngineParams public _params;

debtQueue

A mapping storing debtBlocks that need to be covered by auctions

A debtBlock can be popped from the queue (to be auctioned) if more than popDebtDelay has elapsed since creation

mapping(uint256 _timestamp => uint256 _rad) public debtQueue;

totalOnAuctionDebt

The total amount of debt that is currently on auction in the DebtAuctionHouse

uint256 public totalOnAuctionDebt;

totalQueuedDebt

The total amount of debt that is currently in the debtQueue to be auctioned

uint256 public totalQueuedDebt;

lastSurplusTime

The timestamp of the last time surplus was transferred or auctioned

uint256 public lastSurplusTime;

disableTimestamp

When the contract is disabled (usually by GlobalSettlement) it has to wait disableCooldown before any remaining surplus can be transferred to postSettlementSurplusDrain

uint256 public disableTimestamp;

Functions

addAuthorization

Overriding method allows new authorizations only if the contract is enabled

Method will revert if the account is already authorized

function addAuthorization(address _account) external override(Authorizable, IAuthorizable) isAuthorized whenEnabled;

Parameters

params

Getter for the contract parameters struct

function params() external view returns (AccountingEngineParams memory _accEngineParams);

Returns

constructor

constructor(
  address _safeEngine,
  address _surplusAuctionHouse,
  address _debtAuctionHouse,
  AccountingEngineParams memory _accEngineParams
) Authorizable(msg.sender) validParams;

Parameters

unqueuedUnauctionedDebt

Returns the amount of bad debt that is not in the debtQueue and is not currently handled by debt auctions

The difference between the debt in the SAFEEngine and the debt in the debtQueue and on auction

function unqueuedUnauctionedDebt() external view returns (uint256 __unqueuedUnauctionedDebt);

Returns

_unqueuedUnauctionedDebt

function _unqueuedUnauctionedDebt(uint256 _debtBalance) internal view returns (uint256 __unqueuedUnauctionedDebt);

pushDebtToQueue

Push a block of debt to the debt queue

Usually called by the LiquidationEngine when a SAFE is liquidated

function pushDebtToQueue(uint256 _debtBlock) external isAuthorized;

Parameters

popDebtFromQueue

Pop a block of debt from the debt queue

A debtBlock can be popped from the queue after popDebtDelay seconds have passed since creation

function popDebtFromQueue(uint256 _debtBlockTimestamp) external;

Parameters

settleDebt

Destroy an equal amount of coins and debt

It can only destroy debt that is not locked in the queue and also not in a debt auction (unqueuedUnauctionedDebt)

function settleDebt(uint256 _rad) external;

Parameters

_settleDebt

function _settleDebt(
  uint256 _coinBalance,
  uint256 _debtBalance,
  uint256 _rad
) internal returns (uint256 _newCoinBalance, uint256 _newDebtBalance);

cancelAuctionedDebtWithSurplus

Use surplus coins to destroy debt that was in a debt auction

Usually called by the DebtAuctionHouse after a debt bid is made

function cancelAuctionedDebtWithSurplus(uint256 _rad) external;

Parameters

auctionDebt

Start a debt auction (print protocol tokens in exchange for coins so that the system can be recapitalized)

It can only auction debt that has been popped from the debt queue and is not already being auctioned

function auctionDebt() external returns (uint256 _id);

Returns

auctionSurplus

Start a surplus auction (sell surplus stability fees for protocol tokens)

It can only auction surplus if surplusIsTransferred is set to false

function auctionSurplus() external returns (uint256 _id);

Returns

transferExtraSurplus

Transfer surplus to an address as an alternative to surplus auctions

It can only transfer surplus if surplusIsTransferred is set to true

function transferExtraSurplus() external;

_onContractDisable

Runtime to be run when the contract is disabled (normally triggered by GlobalSettlement)

When it's being disabled, the contract will record the current timestamp. Afterwards, the contract tries to settle as much debt as possible (if there's any) with any surplus that's left in the AccountingEngine

function _onContractDisable() internal override;

transferPostSettlementSurplus

Transfer any remaining surplus after the disable cooldown has passed. Meant to be a backup in case GlobalSettlement.processSAFE has a bug, governance doesn't have power over the system and there's still surplus left in the AccountingEngine which then blocks GlobalSettlement.setOutstandingCoinSupply.

Transfer any remaining surplus after disableCooldown seconds have passed since disabling the contract

function transferPostSettlementSurplus() external whenDisabled;

_modifyParameters

Internal function to be overriden with custom logic to modify parameters

This function is set to revert if not overriden

function _modifyParameters(bytes32 _param, bytes memory _data) internal override;

_setSurplusAuctionHouse

Set the surplus auction house, deny permissions on the old one and approve on the new one

function _setSurplusAuctionHouse(address _surplusAuctionHouse) internal;

_validateParameters

Internal function to be overriden with custom logic to validate parameters

function _validateParameters() internal view override;