Claimer
Author: G9 Software Inc.
This contract uses a variable rate gradual dutch auction to incentivize prize claims on behalf of others. Fees for each canary tier is set to the respective tier's prize size.
State Variables
prizePool
The Prize Pool that this Claimer is claiming prizes for
PrizePool public immutable prizePool;
maxFeePortionOfPrize
The maximum fee that can be charged as a portion of the prize size. Fixed point 18 number
UD2x18 public immutable maxFeePortionOfPrize;
timeToReachMaxFee
The time in seconds to reach the max auction fee
uint256 public immutable timeToReachMaxFee;
Functions
constructor
Constructs a new Claimer
constructor(PrizePool _prizePool, uint256 _timeToReachMaxFee, UD2x18 _maxFeePortionOfPrize);
Parameters
| Name | Type | Description |
|---|---|---|
_prizePool | PrizePool | The prize pool to claim for |
_timeToReachMaxFee | uint256 | The time it should take to reach the maximum fee |
_maxFeePortionOfPrize | UD2x18 | The maximum fee that can be charged as a portion of the prize size. Fixed point 18 number |
claimPrizes
Allows the caller to claim prizes on behalf of others or for themself.
If you are claiming for yourself or don't want to take a fee, set the _feeRecipient and
_minFeePerClaim to zero. This will save some gas on fee calculation.
function claimPrizes(
IClaimable _vault,
uint8 _tier,
address[] calldata _winners,
uint32[][] calldata _prizeIndices,
address _feeRecipient,
uint256 _minFeePerClaim
) external returns (uint256 totalFees);
Parameters
| Name | Type | Description |
|---|---|---|
_vault | IClaimable | The vault to claim from |
_tier | uint8 | The tier to claim for |
_winners | address[] | The array of winners to claim for |
_prizeIndices | uint32[][] | The array of prize indices to claim for each winner (length should match winners) |
_feeRecipient | address | The address to receive the claim fees |
_minFeePerClaim | uint256 | The minimum fee for each claim |
Returns
| Name | Type | Description |
|---|---|---|
totalFees | uint256 | The total fees collected across all successful claims |
_countClaims
If the claimer hasn't specified both a min fee and a fee recipient, we assume that they don't expect a fee and save them some gas on the calculation.
Computes the number of claims that will be made
function _countClaims(address[] calldata _winners, uint32[][] calldata _prizeIndices) internal pure returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_winners | address[] | The array of winners to claim for |
_prizeIndices | uint32[][] | The array of prize indices to claim for each winner (length should match winners) |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The number of claims |
_claim
Claims prizes for a batch of winners and prize indices
function _claim(
IClaimable _vault,
uint8 _tier,
address[] calldata _winners,
uint32[][] calldata _prizeIndices,
address _feeRecipient,
uint96 _feePerClaim
) internal returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_vault | IClaimable | The vault to claim from |
_tier | uint8 | The tier to claim for |
_winners | address[] | The array of winners to claim for |
_prizeIndices | uint32[][] | The array of prize indices to claim for each winner (length should match winners) |
_feeRecipient | address | The address to receive the claim fees |
_feePerClaim | uint96 | The fee to charge for each claim |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The number of claims that were successful |
computeTotalFees
Computes the total fees for the given number of claims.
function computeTotalFees(uint8 _tier, uint256 _claimCount) external view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_tier | uint8 | The tier to claim prizes from |
_claimCount | uint256 | The number of claims |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The total fees for those claims |
computeTotalFees
Computes the total fees for the given number of claims if a number of claims have already been made.
function computeTotalFees(uint8 _tier, uint256 _claimCount, uint256 _claimedCount) public view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_tier | uint8 | The tier to claim prizes from |
_claimCount | uint256 | The number of claims |
_claimedCount | uint256 | The number of prizes already claimed |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The total fees for those claims |
computeFeePerClaim
Computes the fee per claim for the given tier and number of claims
function computeFeePerClaim(uint8 _tier, uint256 _claimCount) external view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_tier | uint8 | The tier to claim prizes from |
_claimCount | uint256 | The number of claims |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The fee that will be taken per claim |
_computeFeePerClaim
Computes the total fees for the given number of claims.
function _computeFeePerClaim(uint8 _tier, uint256 _claimCount, uint256 _claimedCount) internal view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_tier | uint8 | The tier |
_claimCount | uint256 | The number of claims to check |
_claimedCount | uint256 | The number of prizes already claimed |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The total fees for the claims |
computeMaxFee
Computes the maximum fee that can be charged.
function computeMaxFee(uint8 _tier) public view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_tier | uint8 | The tier to compute the max fee for |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The maximum fee that can be charged |
_computeFeeTarget
Compute the target fee for prize claims
function _computeFeeTarget(uint8 _numberOfTiers) internal view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_numberOfTiers | uint8 | The current number of tiers for the prize pool |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The target fee for prize claims |
_computeDecayConstant
Computes the decay constant for the VRGDA.
This is a decay constant that ensures the fee will grow from the target to the max fee within the time frame
function _computeDecayConstant(uint256 _targetFee, uint8 _numberOfTiers) internal view returns (SD59x18);
Parameters
| Name | Type | Description |
|---|---|---|
_targetFee | uint256 | The target fee |
_numberOfTiers | uint8 | The current number of tiers for the prize pool |
Returns
| Name | Type | Description |
|---|---|---|
<none> | SD59x18 | The decay constant |
_computeMaxFee
Computes the max fee given the tier
function _computeMaxFee(uint8 _tier) internal view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_tier | uint8 | The tier to compute the max fee for |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The maximum fee that will be charged for a prize claim for the given tier |
_computeFeeForNextClaim
Computes the fee for the next claim.
function _computeFeeForNextClaim(
uint256 _targetFee,
SD59x18 _decayConstant,
SD59x18 _perTimeUnit,
uint256 _elapsed,
uint256 _sold,
uint256 _maxFee
) internal pure returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_targetFee | uint256 | The target fee that should be charged |
_decayConstant | SD59x18 | The VRGDA decay constant |
_perTimeUnit | SD59x18 | The num to be claimed per second |
_elapsed | uint256 | The number of seconds that have elapsed |
_sold | uint256 | The number of prizes that were claimed |
_maxFee | uint256 | The maximum fee that can be charged |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The fee to charge for the next claim |
Events
ClaimError
Emitted when a claim reverts
event ClaimError(IClaimable indexed vault, uint8 indexed tier, address indexed winner, uint32 prizeIndex, bytes reason);
Parameters
| Name | Type | Description |
|---|---|---|
vault | IClaimable | The vault for which the claim failed |
tier | uint8 | The tier for which the claim failed |
winner | address | The winner for which the claim failed |
prizeIndex | uint32 | The prize index for which the claim failed |
reason | bytes | The revert reason |