V2SwapRouter

Router for stateless execution of swaps against Dragonswap V2

State Variables

DEFAULT_AMOUNT_IN_CACHED

Used as the placeholder value for amountInCached, because the computed amount in for an exact output swap can never actually be this value

uint256 private constant DEFAULT_AMOUNT_IN_CACHED = type(uint256).max;

amountInCached

Transient storage variable used for returning the computed amount in for an exact output swap.

uint256 private amountInCached = DEFAULT_AMOUNT_IN_CACHED;

Functions

getPool

Returns the pool for the given token pair and fee. The pool contract may or may not exist.

function getPool(address tokenA, address tokenB, uint24 fee) private view returns (IDragonswapV2Pool);

dragonswapV2SwapCallback

Called to msg.sender after executing a swap via IDragonswapV2Pool#swap.

In the implementation you must pay the pool tokens owed for the swap. The caller of this method must be checked to be a DragonswapV2Pool deployed by the canonical DragonswapV2Factory. amount0Delta and amount1Delta can both be 0 if no tokens were swapped.

function dragonswapV2SwapCallback(int256 amount0Delta, int256 amount1Delta, bytes calldata _data) external override;

Parameters

Name	Type	Description
amount0Delta	int256	The amount of token0 that was sent (negative) or must be received (positive) by the pool by the end of the swap. If positive, the callback must send that amount of token0 to the pool.
amount1Delta	int256	The amount of token1 that was sent (negative) or must be received (positive) by the pool by the end of the swap. If positive, the callback must send that amount of token1 to the pool.
_data	bytes

exactInputInternal

Performs a single exact input swap

function exactInputInternal(
    uint256 amountIn,
    address recipient,
    uint160 sqrtPriceLimitX96,
    SwapCallbackData memory data
) private returns (uint256 amountOut);

exactInputSingle

Swaps amountIn of one token for as much as possible of another token

Setting amountIn to 0 will cause the contract to look up its own balance, and swap the entire amount, enabling contracts to send tokens before calling this function.

function exactInputSingle(ExactInputSingleParams memory params) external payable override returns (uint256 amountOut);

Parameters

Name	Type	Description
params	ExactInputSingleParams	The parameters necessary for the swap, encoded as ExactInputSingleParams in calldata

Returns

Name	Type	Description
amountOut	uint256	The amount of the received token

exactInput

Swaps amountIn of one token for as much as possible of another along the specified path

Setting amountIn to 0 will cause the contract to look up its own balance, and swap the entire amount, enabling contracts to send tokens before calling this function.

function exactInput(ExactInputParams memory params) external payable override returns (uint256 amountOut);

Parameters

Name	Type	Description
params	ExactInputParams	The parameters necessary for the multi-hop swap, encoded as ExactInputParams in calldata

Returns

Name	Type	Description
amountOut	uint256	The amount of the received token

exactOutputInternal

Performs a single exact output swap

function exactOutputInternal(
    uint256 amountOut,
    address recipient,
    uint160 sqrtPriceLimitX96,
    SwapCallbackData memory data
) private returns (uint256 amountIn);

exactOutputSingle

Swaps as little as possible of one token for amountOut of another token that may remain in the router after the swap.

function exactOutputSingle(ExactOutputSingleParams calldata params)
    external
    payable
    override
    returns (uint256 amountIn);

Parameters

Name	Type	Description
params	ExactOutputSingleParams	The parameters necessary for the swap, encoded as ExactOutputSingleParams in calldata

Returns

Name	Type	Description
amountIn	uint256	The amount of the input token

exactOutput

Swaps as little as possible of one token for amountOut of another along the specified path (reversed) that may remain in the router after the swap.

function exactOutput(ExactOutputParams calldata params) external payable override returns (uint256 amountIn);

Parameters

Name	Type	Description
params	ExactOutputParams	The parameters necessary for the multi-hop swap, encoded as ExactOutputParams in calldata

Returns

Name	Type	Description
amountIn	uint256	The amount of the input token

Structs

SwapCallbackData

struct SwapCallbackData {
    bytes path;
    address payer;
}