Auction.sol
Inherits: Governance, ReentrancyGuard
Author: yearn.fi
General use dutch auction contract for token sales.
State Variables​
WAD​
uint256 internal constant WAD = 1e18;
MINUTE_HALF_LIFE​
Used for the price decay.
uint256 internal constant MINUTE_HALF_LIFE = 0.988514020352896135_356867505 * 1e27;
wantInfo​
Struct to hold the info for want.
TokenInfo internal wantInfo;
hook_​
Contract to call during write functions.
Hook internal hook_;
startingPrice​
The amount to start the auction at.
uint256 public startingPrice;
auctionLength​
The time that each auction lasts.
uint256 public auctionLength;
auctionCooldown​
The minimum time to wait between auction 'kicks'.
uint256 public auctionCooldown;
auctions​
Mapping from an auction ID to its struct.
mapping(bytes32 => AuctionInfo) public auctions;
enabledAuctions​
Array of all the enabled auction for this contract.
bytes32[] public enabledAuctions;
Functions​
constructor​
constructor() Governance(msg.sender);
initialize​
Initializes the Auction contract with initial parameters.
function initialize(
address _want,
address _hook,
address _governance,
uint256 _auctionLength,
uint256 _auctionCooldown,
uint256 _startingPrice
) external virtual;
Parameters
| Name | Type | Description |
|---|---|---|
_want | address | Address this auction is selling to. |
_hook | address | Address of the hook contract (optional). |
_governance | address | Address of the contract governance. |
_auctionLength | uint256 | Duration of each auction in seconds. |
_auctionCooldown | uint256 | Cooldown period between auctions in seconds. |
_startingPrice | uint256 | Starting price for each auction. |
want​
Get the address of this auctions want token.
function want() public view virtual returns (address);
Returns
| Name | Type | Description |
|---|---|---|
<none> | address | . The want token. |
hook​
Get the address of the hook if any.
function hook() external view virtual returns (address);
Returns
| Name | Type | Description |
|---|---|---|
<none> | address | . The hook. |
getHookFlags​
Get the current status of which hooks are being used.
function getHookFlags() external view virtual returns (bool, bool, bool, bool);
Returns
| Name | Type | Description |
|---|---|---|
<none> | bool | . If the kickable hook is used. |
<none> | bool | . If the kick hook is used. |
<none> | bool | . If the preTake hook is used. |
<none> | bool | . If the postTake hook is used. |
numberOfEnabledAuctions​
Get the length of the enabled auctions array.
function numberOfEnabledAuctions() external view virtual returns (uint256);
getAuctionId​
Get the unique auction identifier.
function getAuctionId(address _from) public view virtual returns (bytes32);
Parameters
| Name | Type | Description |
|---|---|---|
_from | address | The address of the token to sell. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bytes32 | bytes32 A unique auction identifier. |
auctionInfo​
Retrieves information about a specific auction.
function auctionInfo(bytes32 _auctionId)
public
view
virtual
returns (address _from, address _to, uint256 _kicked, uint256 _available);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
Returns
| Name | Type | Description |
|---|---|---|
_from | address | The address of the token to sell. |
_to | address | The address of the token to buy. |
_kicked | uint256 | The timestamp of the last kick. |
_available | uint256 | The current available amount for the auction. |
kickable​
Get the pending amount available for the next auction.
Defaults to the auctions balance of the from token if no hook.
function kickable(bytes32 _auctionId) external view virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | uint256 The amount that can be kicked into the auction. |
getAmountNeeded​
Gets the amount of want needed to buy a specific amount of from.
function getAmountNeeded(bytes32 _auctionId, uint256 _amountToTake) external view virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
_amountToTake | uint256 | The amount of from to take in the auction. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | . The amount of want needed to fulfill the take amount. |
getAmountNeeded​
Gets the amount of want needed to buy a specific amount of from at a specific timestamp.
function getAmountNeeded(bytes32 _auctionId, uint256 _amountToTake, uint256 _timestamp)
external
view
virtual
returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
_amountToTake | uint256 | The amount from to take in the auction. |
_timestamp | uint256 | The specific timestamp for calculating the amount needed. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | . The amount of want needed to fulfill the take amount. |
_getAmountNeeded​
Return the amount of want needed to buy _amountToTake.
function _getAmountNeeded(AuctionInfo memory _auction, uint256 _amountToTake, uint256 _timestamp)
internal
view
virtual
returns (uint256);
price​
Gets the price of the auction at the current timestamp.
function price(bytes32 _auctionId) external view virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | . The price of the auction. |
price​
Gets the price of the auction at a specific timestamp.
function price(bytes32 _auctionId, uint256 _timestamp) public view virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
_timestamp | uint256 | The specific timestamp for calculating the price. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | . The price of the auction. |
_price​
Internal function to calculate the scaled price based on auction parameters.
function _price(uint256 _kicked, uint256 _available, uint256 _timestamp) internal view virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_kicked | uint256 | The timestamp the auction was kicked. |
_available | uint256 | The initial available amount scaled 1e18. |
_timestamp | uint256 | The specific timestamp for calculating the price. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | . The calculated price scaled to 1e18. |
enable​
Enables a new auction.
Uses governance as the receiver.
function enable(address _from) external virtual returns (bytes32);
Parameters
| Name | Type | Description |
|---|---|---|
_from | address | The address of the token to be auctioned. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bytes32 | . The unique identifier of the enabled auction. |
enable​
Enables a new auction.
function enable(address _from, address _receiver) public virtual onlyGovernance returns (bytes32 _auctionId);
Parameters
| Name | Type | Description |
|---|---|---|
_from | address | The address of the token to be auctioned. |
_receiver | address | The address that will receive the funds in the auction. |
Returns
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the enabled auction. |
disable​
Disables an existing auction.
Only callable by governance.
function disable(address _from) external virtual;
Parameters
| Name | Type | Description |
|---|---|---|
_from | address | The address of the token being sold. |
disable​
Disables an existing auction.
Only callable by governance.
function disable(address _from, uint256 _index) public virtual onlyGovernance;
Parameters
| Name | Type | Description |
|---|---|---|
_from | address | The address of the token being sold. |
_index | uint256 | The index the auctionId is at in the array. |
setHookFlags​
Set the flags to be used with hook.
function setHookFlags(bool _kickable, bool _kick, bool _preTake, bool _postTake) external virtual onlyGovernance;
Parameters
| Name | Type | Description |
|---|---|---|
_kickable | bool | If the kickable hook should be used. |
_kick | bool | If the kick hook should be used. |
_preTake | bool | If the preTake hook should be used. |
_postTake | bool | If the postTake should be used. |
kick​
Kicks off an auction, updating its status and making funds available for bidding.
function kick(bytes32 _auctionId) external virtual nonReentrant returns (uint256 available);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
Returns
| Name | Type | Description |
|---|---|---|
available | uint256 | The available amount for bidding on in the auction. |
take​
Take the token being sold in a live auction.
Defaults to taking the full amount and sending to the msg sender.
function take(bytes32 _auctionId) external virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | . The amount of fromToken taken in the auction. |
take​
Take the token being sold in a live auction with a specified maximum amount.
Uses the sender's address as the receiver.
function take(bytes32 _auctionId, uint256 _maxAmount) external virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
_maxAmount | uint256 | The maximum amount of fromToken to take in the auction. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | . The amount of fromToken taken in the auction. |
take​
Take the token being sold in a live auction.
function take(bytes32 _auctionId, uint256 _maxAmount, address _receiver) external virtual returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
_maxAmount | uint256 | The maximum amount of fromToken to take in the auction. |
_receiver | address | The address that will receive the fromToken. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | _amountTaken The amount of fromToken taken in the auction. |
take​
Take the token being sold in a live auction.
function take(bytes32 _auctionId, uint256 _maxAmount, address _receiver, bytes calldata _data)
external
virtual
returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_auctionId | bytes32 | The unique identifier of the auction. |
_maxAmount | uint256 | The maximum amount of fromToken to take in the auction. |
_receiver | address | The address that will receive the fromToken. |
_data | bytes | The data signify the callback should be used and sent with it. |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | _amountTaken The amount of fromToken taken in the auction. |
_take​
Implements the take of the auction.
function _take(bytes32 _auctionId, uint256 _maxAmount, address _receiver, bytes memory _data)
internal
virtual
nonReentrant
returns (uint256 _amountTaken);
Events​
AuctionEnabled​
Emitted when a new auction is enabled
event AuctionEnabled(bytes32 auctionId, address indexed from, address indexed to, address indexed auctionAddress);
AuctionDisabled​
Emitted when an auction is disabled.
event AuctionDisabled(bytes32 auctionId, address indexed from, address indexed to, address indexed auctionAddress);
AuctionKicked​
Emitted when auction has been kicked.
event AuctionKicked(bytes32 auctionId, uint256 available);
AuctionTaken​
Emitted when any amount of an active auction was taken.
event AuctionTaken(bytes32 auctionId, uint256 amountTaken, uint256 amountLeft);
Structs​
TokenInfo​
Store address and scaler in one slot.
struct TokenInfo {
address tokenAddress;
uint96 scaler;
}
AuctionInfo​
Store all the auction specific information.
struct AuctionInfo {
TokenInfo fromInfo;
uint96 kicked;
address receiver;
uint128 initialAvailable;
uint128 currentAvailable;
}
Hook​
Store the hook address and each flag in one slot.
struct Hook {
address hook;
bool kickable;
bool kick;
bool preTake;
bool postTake;
}