gToken

The goal of gTokens is to achieve front-running resistance on DEXs such as Uniswap. When two different gTokens are swapped, users can rest assured that the swapping transaction will not be attacked by front-running bots or malicious miners. This is achieved by inheriting the ERC20 contract, with modified function methods. Methods such as transferFrom() requires that it has to be invoked only from a trusted relayer.

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constructor()

   constructor(address _token, address _controller);

Initializes the contract, then wraps the ERC20 token and assigns the Controller contract instance.

Parameter	Type
_token	address	The ERC20 Token Address
_controller	address	The address of the Controller instance

onlyController()

modifier onlyController();

Verifies msg.sender is the Controller address. Otherwise, reverts function calls.

setController()

function setController(address _controller) public onlyOwner();

Sets the Controller instance, can only be invoked by the contract owner.

Parameter	Type
_controller	address	The address of the Controller instance

transferFrom()

function transferFrom(
    address sender, 
    address recipient, 
    uint256 amount
) public override returns (bool);

Transfers gTokens from a given address to the recipient. The sender is always the address of the Controller, the transaction is not necessarily originated from the Controller contract itself, as long as the origin address is one of the trusted relayers. For the direct call method, see internalTransferFrom().

Parameter	Type
sender	address	The address of a trusted relayer
recipient	address	The recipient's address, most likely a token pair address. For example, an address returned by Uniswap's getPair(tokenA, tokenB).
amount	uint256	The amount of token to be transferred.

This method reverts if it is not invoked from a trusted relayer. Otherwise, returns true.

transfer()

function transfer(address recipient, uint256 amount) public override returns (bool);

Transfers gTokens to a recipient. This method can only be invoked by a trusted token pair.

Parameter	Type
recipient	address	The recipient's address
amount	uint256	The amount of token to be transferred

internalTransferFrom()

function internalTransferFrom(
    address sender,
    address recipient,
    uint256 amount
) public onlyController();

Transfers gTokens from a given address to the recipient, similar to transferFrom(). This method can only be invoked directly from the Controller contract.

Parameter	Type
sender	address	The sender's address
recipient	address	The recipient's address
amount	uint256	The amount of token to be transferred

deposit()

function deposit(uint256 amount) public;

Wraps ERC20 token to a gToken. The gToken smart contract stores an amount of ERC20 token as a reserve and mints the same amount of wrapped ERC20 token.

Parameter	Type
amount	uint256	The amount of token to be transferred

withdraw()

function withdraw(uint256 amount) public;

Withdraws ERC20 token from the smart contract and burns the wrapped token.

Parameter	Type
amount	uint256	The amount of token to be transferred