ConstantProductPool
This is a Trident exchange pool template with constant product formula for swapping between an ERC-20 token pair.
The full contract can be found here.
Functions
mint
function mint(bytes calldata data) public override nonReentrant returns (uint256 liquidity)
Mints LP tokens and returns the amount of liquidity; should be called via the router after transferring bento tokens.
Parameters
| Name | Type | Description |
|---|
data | bytes | data needed to mint LP tokens |
Returns
| Name | Type | Description |
|---|
liquidity | uint256 | amount of liquidity |
burn
function burn(bytes calldata data) public override nonReentrant returns (IPool.TokenAmount[] memory withdrawnAmounts)
Burns LP tokens that are sent to this contract and returns the withdrawn amounts.
Parameters
| Name | Type | Description |
|---|
data | bytes | data needed to burn LP tokens |
Returns
| Name | Type | Description |
|---|
withdrawnAmounts | IPool.TokenAmount[] | array of withdrawn amounts |
burnSingle
function burnSingle(bytes calldata data) public override nonReentrant returns (uint256 amountOut)
Burns LP tokens that are sent to this contract and swaps one of the output tokens for another.
Parameters
| Name | Type | Description |
|---|
data | bytes | data needed to burn LP tokens |
Returns
| Name | Type | Description |
|---|
amountOut | uint256 | amount of output token |
swap
function swap(bytes calldata data) public override nonReentrant returns (uint256 amountOut)
Swaps one token for another; the router must prefund this contract and ensure there isn't too much slippage.
Parameters
| Name | Type | Description |
|---|
data | bytes | data needed to swap tokens |
Returns
| Name | Type | Description |
|---|
amountOut | uint256 | amount of token received in swap |
flashSwap
function flashSwap(bytes calldata data) public override nonReentrant returns (uint256 amountOut)
Flash swaps one token for another; the router must support swap callbacks and ensure there isn't too much slippage.
Parameters
| Name | Type | Description |
|---|
data | bytes | data needed to flash swap tokens |
Returns
| Name | Type | Description |
|---|
amountOut | uint256 | amount of token received in swap |
updateBarParameters
function updateBarParameters() public
Updates barFee and barFeeTo for Trident protocol.
_update
function _update(
uint256 balance0,
uint256 balance1,
uint112 _reserve0,
uint112 _reserve1,
uint32 _blockTimestampLast
) internal
Internal function that updates balances and reserves of pool.
Parameters
| Name | Type | Description |
|---|
balance0 | uint256 | balance of asset to update |
balance1 | uint256 | balance of other asset to update |
_reserve0 | uint112 | reserves of first asset |
_reserve1 | uint112 | reserves of second asset |
_blockTimestampLast | uint32 | timestamp |
_mintFee
function _mintFee(uint112 _reserve0, uint112 _reserve1) internal returns (uint256 _totalSupply, uint256 computed)
Internal function that mints and transfers bar fees to the receiver and returns the total supply as well as the computed amount of bar fees.
Parameters
| Name | Type | Description |
|---|
_reserve0 | uint112 | first reserve to calculate fees on |
_reserve1 | uint112 | second reserve to calculate fees on |
Returns
| Name | Type | Description |
|---|
_totalSupply | uint256 | first reserve to calculate fees on |
computed | uint256 | second reserve to calculate fees on |
_getAmountOut
function _getAmountOut(
uint256 amountIn,
uint256 reserveAmountIn,
uint256 reserveAmountOut
) internal view returns (uint256 amountOut)
Internal function that calculates the amount of an asset to remove and returns that amount.
Parameters
| Name | Type | Description |
|---|
amountIn | uint256 | amount of tokens user has in pool |
reserveAmountIn | uint256 | amount to go into reserve |
reserveAmountOut | uint256 | amount to come out of reserve |
Returns
| Name | Type | Description |
|---|
amountOut | uint256 | amount of tokens to be removed |
_getAmountIn
function _getAmountIn(
uint256 amountOut,
uint256 reserveAmountIn,
uint256 reserveAmountOut
) internal view returns (uint256 amountIn)
Internal function that calculates the amount of an asset to add and returns that amount.
Parameters
| Name | Type | Description |
|---|
amountOut | uint256 | amount of tokens user is trying to add |
reserveAmountIn | uint256 | amount to go into reserve |
reserveAmountOut | uint256 | amount to come out of reserve |
Returns
| Name | Type | Description |
|---|
amountIn | uint256 | amount of tokens to be added |
getAmountOut
function getAmountOut(bytes calldata data) public view override returns (uint256 finalAmountOut)
Calls _getAmountOut and calculates the amount of an asset to remove.
Paramters
| Name | Type | Description |
|---|
data | bytes | data needed for calculations |
Returns
| Name | Type | Description |
|---|
finalAmountOut | uint256 | amount of tokens to be removed |
getAmountIn
function getAmountIn(bytes calldata data) public view override returns (uint256 finalAmountIn)
Calls _getAmountIn and calculates the amount of an asset to add.
Paramters
| Name | Type | Description |
|---|
data | bytes | data needed for calculations |
Returns
| Name | Type | Description |
|---|
finalAmountIn | uint256 | amount of tokens to be added |
_transfer
function _transfer(
address token,
uint256 shares,
address to,
bool unwrapBento
) internal
Internal function that transfers bento shares.
Parameters
| Name | Type | Description |
|---|
token | address | address of token to transfer |
shares | uint256 | amount of shares to transfer |
to | address | address of receiver |
unwrapBento | bool | boolean for whether to unwrap bento shares or not |
_nonOptimalMintFee
function _nonOptimalMintFee(
uint256 _amount0,
uint256 _amount1,
uint256 _reserve0,
uint256 _reserve1
) internal view returns (uint256 token0Fee, uint256 token1Fee)
Internal function that calculates the non-optimal mint fee, which is a fee charged to cover for swapFee when users add unbalanced liquidity, and returns it for each asset.
Parameters
| Name | Type | Description |
|---|
_amount0 | uint256 | amount of token0 |
_amount1 | uint256 | amount of token1 |
_reserve0 | uint256 | amount of reserve0 |
_reserve1 | uint256 | amount of reserve1 |
Returns
| Name | Type | Description |
|---|
token0Fee | uint256 | token0 non-optimal mint fee |
token1Fee | uint256 | token1 non-optimal mint fee |
getAssets
function getAssets() public view override returns (address[] memory assets)
Returns an array containing the addresses of the two assets.
Returns
| Name | Type | Description |
|---|
assets | address[] | array containing both asset addresses |
_getReserves
function _getReserves()
internal
view
returns (
uint112 _reserve0,
uint112 _reserve1,
uint32 _blockTimestampLast
)
Internal function that returns the amount of reserves in bento shares.
Returns
| Name | Type | Description |
|---|
_reserve0 | uint112 | amount of reserve0 |
_reserve1 | uint112 | amount of reserve1 |
_blockTimestampLast | uint32 | timestamp |
getReserves
function getReserves()
public
view
returns (
uint112 _reserve0,
uint112 _reserve1,
uint32 _blockTimestampLast
)
Calls _getReserves and returns the amount of reserves in bento shares.
Returns
| Name | Type | Description |
|---|
_reserve0 | uint112 | amount of reserve0 |
_reserve1 | uint112 | amount of reserve1 |
_blockTimestampLast | uint32 | timestamp |
getNativeReserves
function getNativeReserves()
public
view
returns (
uint256 _nativeReserve0,
uint256 _nativeReserve1,
uint32 _blockTimestampLast
)
Returns the amount of reserces in native ERC-20 token amounts.
Returns
| Name | Type | Description |
|---|
_reserve0 | uint112 | amount of reserve0 (in native token) |
_reserve1 | uint112 | amount of reserve1 (in native token) |
_blockTimestampLast | uint32 | timestamp |