Liquidatable
Liquidatable
The liquidation has a liveness period before expiring successfully, during which someone can "dispute" the liquidation, which sends a price request to the relevant Oracle to settle the final collateralization ratio based on a DVM price. The contract enforces dispute rewards in order to incentivize disputers to correctly dispute false liquidations and compensate position sponsors who had their position incorrectly liquidated. Importantly, a prospective disputer must deposit a dispute bond that they can lose in the case of an unsuccessful dispute. NOTE: this contract does not work with ERC777 collateral currencies or any others that call into the receiver on transfer(). Using an ERC777 token would allow a user to maliciously grief other participants (while also losing money themselves).
nonReentrant()
modifier
Prevents a contract from calling itself, directly or indirectly.
Calling a nonReentrant
function from another nonReentrant
function is not supported. It is possible to prevent this from happening
by making the nonReentrant
function external, and make it call a
private
function that does the actual work.
nonReentrantView()
modifier
Designed to prevent a view-only method from being re-entered during a call to a nonReentrant()
state-changing method.
constructor(struct Liquidatable.ConstructorParams params)
public
Constructs the liquidatable contract.
Parameters:
-
params
: struct to define input parameters for construction of Liquidatable. Some params are fed directly into the PricelessPositionManager’s constructor within the inheritance tree.
createLiquidation(address sponsor, struct FixedPoint.Unsigned minCollateralPerToken, struct FixedPoint.Unsigned maxCollateralPerToken, struct FixedPoint.Unsigned maxTokensToLiquidate, uint256 deadline) → uint256 liquidationId, struct FixedPoint.Unsigned tokensLiquidated, struct FixedPoint.Unsigned finalFeeBond
external
Liquidates the sponsor’s position if the caller has enough synthetic tokens to retire the position’s outstanding tokens. Liquidations above a minimum size also reset an ongoing "slow withdrawal"'s liveness.
This method generates an ID that will uniquely identify liquidation for the sponsor. This contract must be
approved to spend at least tokensLiquidated
of tokenCurrency
and at least finalFeeBond
of collateralCurrency
.
This contract must have the Burner role for the tokenCurrency
.
Parameters:
-
sponsor
: address of the sponsor to liquidate. -
minCollateralPerToken
: abort the liquidation if the position’s collateral per token is below this value. -
maxCollateralPerToken
: abort the liquidation if the position’s collateral per token exceeds this value. -
maxTokensToLiquidate
: max number of tokens to liquidate. -
deadline
: abort the liquidation if the transaction is mined after this timestamp.
dispute(uint256 liquidationId, address sponsor) → struct FixedPoint.Unsigned totalPaid
external
Disputes a liquidation, if the caller has enough collateral to post a dispute bond and pay a fixed final fee charged on each price request.
Can only dispute a liquidation before the liquidation expires and if there are no other pending disputes.
This contract must be approved to spend at least the dispute bond amount of collateralCurrency
. This dispute
bond amount is calculated from disputeBondPercentage
times the collateral in the liquidation.
Parameters:
-
liquidationId
: of the disputed liquidation. -
sponsor
: the address of the sponsor whose liquidation is being disputed.
withdrawLiquidation(uint256 liquidationId, address sponsor) → struct Liquidatable.RewardsData
public
After a dispute has settled or after a non-disputed liquidation has expired, anyone can call this method to disperse payments to the sponsor, liquidator, and disdputer.
If the dispute SUCCEEDED: the sponsor, liquidator, and disputer are eligible for payment. If the dispute FAILED: only the liquidator can receive payment. This method will revert if rewards have already been dispersed.
Parameters:
-
liquidationId
: uniquely identifies the sponsor’s liquidation. -
sponsor
: address of the sponsor associated with the liquidation.
getLiquidations(address sponsor) → struct Liquidatable.LiquidationData[] liquidationData
external
Gets all liquidation information for a given sponsor address.
Parameters:
-
sponsor
: address of the position sponsor.
transformCollateralRequirement(struct FixedPoint.Unsigned price) → struct FixedPoint.Unsigned
public
Accessor method to calculate a transformed collateral requirement using the finanical product library specified during contract deployment. If no library was provided then no modification to the collateral requirement is done.
This method should never revert.
Parameters:
-
price
: input price used as an input to transform the collateral requirement.
_getLiquidationData(address sponsor, uint256 liquidationId) → struct Liquidatable.LiquidationData liquidation
internal
_transformCollateralRequirement(struct FixedPoint.Unsigned price) → struct FixedPoint.Unsigned
internal
requestTransferPosition()
public
Requests to transfer ownership of the caller’s current position to a new sponsor address. Once the request liveness is passed, the sponsor can execute the transfer and specify the new sponsor.
The liveness length is the same as the withdrawal liveness.
transferPositionPassedRequest(address newSponsorAddress)
public
After a passed transfer position request (i.e., by a call to requestTransferPosition
and waiting
withdrawalLiveness
), transfers ownership of the caller’s current position to newSponsorAddress
.
Transferring positions can only occur if the recipient does not already have a position.
Parameters:
-
newSponsorAddress
: is the address to which the position will be transferred.
depositTo(address sponsor, struct FixedPoint.Unsigned collateralAmount)
public
Transfers collateralAmount
of collateralCurrency
into the specified sponsor’s position.
Increases the collateralization level of a position after creation. This contract must be approved to spend
at least collateralAmount
of collateralCurrency
.
Parameters:
-
sponsor
: the sponsor to credit the deposit to. -
collateralAmount
: total amount of collateral tokens to be sent to the sponsor’s position.
deposit(struct FixedPoint.Unsigned collateralAmount)
public
Transfers collateralAmount
of collateralCurrency
into the caller’s position.
Increases the collateralization level of a position after creation. This contract must be approved to spend
at least collateralAmount
of collateralCurrency
.
Parameters:
-
collateralAmount
: total amount of collateral tokens to be sent to the sponsor’s position.
withdraw(struct FixedPoint.Unsigned collateralAmount) → struct FixedPoint.Unsigned amountWithdrawn
public
Transfers collateralAmount
of collateralCurrency
from the sponsor’s position to the sponsor.
Reverts if the withdrawal puts this position’s collateralization ratio below the global collateralization
ratio. In that case, use requestWithdrawal
. Might not withdraw the full requested amount to account for precision loss.
Parameters:
-
collateralAmount
: is the amount of collateral to withdraw.
requestWithdrawal(struct FixedPoint.Unsigned collateralAmount)
public
Starts a withdrawal request that, if passed, allows the sponsor to withdraw` from their position.
The request will be pending for withdrawalLiveness
, during which the position can be liquidated.
Parameters:
-
collateralAmount
: the amount of collateral requested to withdraw
withdrawPassedRequest() → struct FixedPoint.Unsigned amountWithdrawn
external
After a passed withdrawal request (i.e., by a call to requestWithdrawal
and waiting
withdrawalLiveness
), withdraws positionData.withdrawalRequestAmount
of collateral currency.
Might not withdraw the full requested amount in order to account for precision loss or if the full requested amount exceeds the collateral in the position (due to paying fees).
create(struct FixedPoint.Unsigned collateralAmount, struct FixedPoint.Unsigned numTokens)
public
Creates tokens by creating a new position or by augmenting an existing position. Pulls collateralAmount
into the sponsor’s position and mints numTokens
of tokenCurrency
.
Reverts if minting these tokens would put the position’s collateralization ratio below the
global collateralization ratio. This contract must be approved to spend at least collateralAmount
of
collateralCurrency
.
This contract must have the Minter role for the tokenCurrency
.
Parameters:
-
collateralAmount
: is the number of collateral tokens to collateralize the position with -
numTokens
: is the number of tokens to mint from the position.
repay(struct FixedPoint.Unsigned numTokens)
public
Burns numTokens
of tokenCurrency
to decrease sponsors position size, without sending back collateralCurrency
.
This is done by a sponsor to increase position CR. Resulting size is bounded by minSponsorTokens.
Can only be called by token sponsor. This contract must be approved to spend numTokens
of tokenCurrency
.
This contract must have the Burner role for the tokenCurrency
.
Parameters:
-
numTokens
: is the number of tokens to be burnt from the sponsor’s debt position.
redeem(struct FixedPoint.Unsigned numTokens) → struct FixedPoint.Unsigned amountWithdrawn
public
Burns numTokens
of tokenCurrency
and sends back the proportional amount of collateralCurrency
.
Can only be called by a token sponsor. Might not redeem the full proportional amount of collateral
in order to account for precision loss. This contract must be approved to spend at least numTokens
of
tokenCurrency
.
This contract must have the Burner role for the tokenCurrency
.
Parameters:
-
numTokens
: is the number of tokens to be burnt for a commensurate amount of collateral.
settleExpired() → struct FixedPoint.Unsigned amountWithdrawn
external
After a contract has passed expiry all token holders can redeem their tokens for underlying at the
prevailing price defined by the DVM from the expire
function.
This burns all tokens from the caller of tokenCurrency
and sends back the proportional amount of
collateralCurrency
. Might not redeem the full proportional amount of collateral in order to account for
precision loss. This contract must be approved to spend tokenCurrency
at least up to the caller’s full balance.
This contract must have the Burner role for the tokenCurrency
.
expire()
external
Locks contract state in expired and requests oracle price.
this function can only be called once the contract is expired and can’t be re-called.
emergencyShutdown()
external
Premature contract settlement under emergency circumstances.
Only the governor can call this function as they are permissioned within the FinancialContractAdmin
.
Upon emergency shutdown, the contract settlement time is set to the shutdown time. This enables withdrawal
to occur via the standard settleExpired
function. Contract state is set to ExpiredPriceRequested
which prevents re-entry into this function or the expire
function. No fees are paid when calling
emergencyShutdown
as the governor who would call the function would also receive the fees.
remargin()
external
Theoretically supposed to pay fees and move money between margin accounts to make sure they reflect the NAV of the contract. However, this functionality doesn’t apply to this contract.
This is supposed to be implemented by any contract that inherits AdministrateeInterface
and callable
only by the Governor contract. This method is therefore minimally implemented in this contract and does nothing.
getCollateral(address sponsor) → struct FixedPoint.Unsigned
external
Accessor method for a sponsor’s collateral.
This is necessary because the struct returned by the positions() method shows
rawCollateral, which isn’t a user-readable value.
This method accounts for pending regular fees that have not yet been withdrawn from this contract, for
example if the lastPaymentTime != currentTime
.
Parameters:
-
sponsor
: address whose collateral amount is retrieved.
totalPositionCollateral() → struct FixedPoint.Unsigned
external
Accessor method for the total collateral stored within the PricelessPositionManager.
This method accounts for pending regular fees that have not yet been withdrawn from this contract, for
example if the lastPaymentTime != currentTime
.
transformPrice(struct FixedPoint.Unsigned price, uint256 requestTime) → struct FixedPoint.Unsigned
public
Accessor method to compute a transformed price using the finanicalProductLibrary specified at contract deployment. If no library was provided then no modification to the price is done.
This method should never revert.
Parameters:
-
price
: input price to be transformed. -
requestTime
: timestamp the oraclePrice was requested at.
transformPriceIdentifier(uint256 requestTime) → bytes32
public
Accessor method to compute a transformed price identifier using the finanicalProductLibrary specified at contract deployment. If no library was provided then no modification to the identifier is done.
This method should never revert.
Parameters:
-
requestTime
: timestamp the identifier is to be used at.
_reduceSponsorPosition(address sponsor, struct FixedPoint.Unsigned tokensToRemove, struct FixedPoint.Unsigned collateralToRemove, struct FixedPoint.Unsigned withdrawalAmountToRemove)
internal
_incrementCollateralBalances(struct PricelessPositionManager.PositionData positionData, struct FixedPoint.Unsigned collateralAmount) → struct FixedPoint.Unsigned
internal
_decrementCollateralBalances(struct PricelessPositionManager.PositionData positionData, struct FixedPoint.Unsigned collateralAmount) → struct FixedPoint.Unsigned
internal
_decrementCollateralBalancesCheckGCR(struct PricelessPositionManager.PositionData positionData, struct FixedPoint.Unsigned collateralAmount) → struct FixedPoint.Unsigned
internal
_transformPrice(struct FixedPoint.Unsigned price, uint256 requestTime) → struct FixedPoint.Unsigned
internal
payRegularFees() → struct FixedPoint.Unsigned
public
Pays UMA DVM regular fees (as a % of the collateral pool) to the Store contract.
These must be paid periodically for the life of the contract. If the contract has not paid its regular fee in a week or more then a late penalty is applied which is sent to the caller. If the amount of fees owed are greater than the pfc, then this will pay as much as possible from the available collateral. An event is only fired if the fees charged are greater than 0.
getOutstandingRegularFees(uint256 time) → struct FixedPoint.Unsigned regularFee, struct FixedPoint.Unsigned latePenalty, struct FixedPoint.Unsigned totalPaid
public
Fetch any regular fees that the contract has pending but has not yet paid. If the fees to be paid are more than the total collateral within the contract then the totalPaid returned is full contract collateral amount.
This returns 0 and exit early if there is no pfc, fees were already paid during the current block, or the fee rate is 0.
pfc() → struct FixedPoint.Unsigned
external
Gets the current profit from corruption for this contract in terms of the collateral currency.
This is equivalent to the collateral pool available from which to pay fees. Therefore, derived contracts are expected to implement this so that pay-fee methods can correctly compute the owed fees as a % of PfC.
gulp()
external
Removes excess collateral balance not counted in the PfC by distributing it out pro-rata to all sponsors.
- Multiplying the
cumulativeFeeMultiplier
by the ratio of non-PfC-collateral -
PfC-collateral effectively pays all sponsors a pro-rata portion of the excess collateral. This will revert if PfC is 0 and this contract’s collateral balance > 0.
_getFeeAdjustedCollateral(struct FixedPoint.Unsigned rawCollateral) → struct FixedPoint.Unsigned collateral
internal
_getPendingRegularFeeAdjustedCollateral(struct FixedPoint.Unsigned rawCollateral) → struct FixedPoint.Unsigned
internal
_convertToRawCollateral(struct FixedPoint.Unsigned collateral) → struct FixedPoint.Unsigned rawCollateral
internal
_removeCollateral(struct FixedPoint.Unsigned rawCollateral, struct FixedPoint.Unsigned collateralToRemove) → struct FixedPoint.Unsigned removedCollateral
internal
_addCollateral(struct FixedPoint.Unsigned rawCollateral, struct FixedPoint.Unsigned collateralToAdd) → struct FixedPoint.Unsigned addedCollateral
internal
_adjustCumulativeFeeMultiplier(struct FixedPoint.Unsigned amount, struct FixedPoint.Unsigned currentPfc)
internal
setCurrentTime(uint256 time)
external
Sets the current time.
Will revert if not running in test mode.
Parameters:
-
time
: timestamp to set current Testable time to.
getCurrentTime() → uint256
public
Gets the current time. Will return the last time set in setCurrentTime
if running in test mode.
Otherwise, it will return the block timestamp.