// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.10;
/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 {
/*///////////////////////////////////////////////////////////////
EVENTS
//////////////////////////////////////////////////////////////*/
event Transfer(address indexed from, address indexed to, uint256 amount);
event Approval(address indexed owner, address indexed spender, uint256 amount);
/*///////////////////////////////////////////////////////////////
METADATA STORAGE
//////////////////////////////////////////////////////////////*/
string public name;
string public symbol;
uint8 public immutable decimals;
/*///////////////////////////////////////////////////////////////
ERC20 STORAGE
//////////////////////////////////////////////////////////////*/
uint256 public totalSupply;
mapping(address => uint256) public balanceOf;
mapping(address => mapping(address => uint256)) public allowance;
/*///////////////////////////////////////////////////////////////
EIP-2612 STORAGE
//////////////////////////////////////////////////////////////*/
uint256 internal immutable INITIAL_CHAIN_ID;
bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;
mapping(address => uint256) public nonces;
/*///////////////////////////////////////////////////////////////
CONSTRUCTOR
//////////////////////////////////////////////////////////////*/
constructor(
string memory _name,
string memory _symbol,
uint8 _decimals
) {
name = _name;
symbol = _symbol;
decimals = _decimals;
INITIAL_CHAIN_ID = block.chainid;
INITIAL_DOMAIN_SEPARATOR = computeDomainSeparator();
}
/*///////////////////////////////////////////////////////////////
ERC20 LOGIC
//////////////////////////////////////////////////////////////*/
function approve(address spender, uint256 amount) public virtual returns (bool) {
allowance[msg.sender][spender] = amount;
emit Approval(msg.sender, spender, amount);
return true;
}
function transfer(address to, uint256 amount) public virtual returns (bool) {
balanceOf[msg.sender] -= amount;
// Cannot overflow because the sum of all user
// balances can't exceed the max uint256 value.
unchecked {
balanceOf[to] += amount;
}
emit Transfer(msg.sender, to, amount);
return true;
}
function transferFrom(
address from,
address to,
uint256 amount
) public virtual returns (bool) {
uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.
if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;
balanceOf[from] -= amount;
// Cannot overflow because the sum of all user
// balances can't exceed the max uint256 value.
unchecked {
balanceOf[to] += amount;
}
emit Transfer(from, to, amount);
return true;
}
/*///////////////////////////////////////////////////////////////
EIP-2612 LOGIC
//////////////////////////////////////////////////////////////*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public virtual {
require(deadline >= block.timestamp, "PERMIT_DEADLINE_EXPIRED");
// Unchecked because the only math done is incrementing
// the owner's nonce which cannot realistically overflow.
unchecked {
bytes32 digest = keccak256(
abi.encodePacked(
"\x19\x01",
DOMAIN_SEPARATOR(),
keccak256(
abi.encode(
keccak256(
"Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
),
owner,
spender,
value,
nonces[owner]++,
deadline
)
)
)
);
address recoveredAddress = ecrecover(digest, v, r, s);
require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");
allowance[recoveredAddress][spender] = value;
}
emit Approval(owner, spender, value);
}
function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : computeDomainSeparator();
}
function computeDomainSeparator() internal view virtual returns (bytes32) {
return
keccak256(
abi.encode(
keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
keccak256(bytes(name)),
keccak256("1"),
block.chainid,
address(this)
)
);
}
/*///////////////////////////////////////////////////////////////
INTERNAL MINT/BURN LOGIC
//////////////////////////////////////////////////////////////*/
function _mint(address to, uint256 amount) internal virtual {
totalSupply += amount;
// Cannot overflow because the sum of all user
// balances can't exceed the max uint256 value.
unchecked {
balanceOf[to] += amount;
}
emit Transfer(address(0), to, amount);
}
function _burn(address from, uint256 amount) internal virtual {
balanceOf[from] -= amount;
// Cannot underflow because a user's balance
// will never be larger than the total supply.
unchecked {
totalSupply -= amount;
}
emit Transfer(from, address(0), amount);
}
}
/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/SafeTransferLib.sol)
/// @author Modified from Gnosis (https://github.com/gnosis/gp-v2-contracts/blob/main/src/contracts/libraries/GPv2SafeERC20.sol)
/// @dev Use with caution! Some functions in this library knowingly create dirty bits at the destination of the free memory pointer.
/// @dev Note that none of the functions in this library check that a token has code at all! That responsibility is delegated to the caller.
library SafeTransferLib {
/*///////////////////////////////////////////////////////////////
ETH OPERATIONS
//////////////////////////////////////////////////////////////*/
function safeTransferETH(address to, uint256 amount) internal {
bool callStatus;
assembly {
// Transfer the ETH and store if it succeeded or not.
callStatus := call(gas(), to, amount, 0, 0, 0, 0)
}
require(callStatus, "ETH_TRANSFER_FAILED");
}
/*///////////////////////////////////////////////////////////////
ERC20 OPERATIONS
//////////////////////////////////////////////////////////////*/
function safeTransferFrom(
ERC20 token,
address from,
address to,
uint256 amount
) internal {
bool callStatus;
assembly {
// Get a pointer to some free memory.
let freeMemoryPointer := mload(0x40)
// Write the abi-encoded calldata to memory piece by piece:
mstore(freeMemoryPointer, 0x23b872dd00000000000000000000000000000000000000000000000000000000) // Begin with the function selector.
mstore(add(freeMemoryPointer, 4), and(from, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "from" argument.
mstore(add(freeMemoryPointer, 36), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "to" argument.
mstore(add(freeMemoryPointer, 68), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.
// Call the token and store if it succeeded or not.
// We use 100 because the calldata length is 4 + 32 * 3.
callStatus := call(gas(), token, 0, freeMemoryPointer, 100, 0, 0)
}
require(didLastOptionalReturnCallSucceed(callStatus), "TRANSFER_FROM_FAILED");
}
function safeTransfer(
ERC20 token,
address to,
uint256 amount
) internal {
bool callStatus;
assembly {
// Get a pointer to some free memory.
let freeMemoryPointer := mload(0x40)
// Write the abi-encoded calldata to memory piece by piece:
mstore(freeMemoryPointer, 0xa9059cbb00000000000000000000000000000000000000000000000000000000) // Begin with the function selector.
mstore(add(freeMemoryPointer, 4), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "to" argument.
mstore(add(freeMemoryPointer, 36), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.
// Call the token and store if it succeeded or not.
// We use 68 because the calldata length is 4 + 32 * 2.
callStatus := call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)
}
require(didLastOptionalReturnCallSucceed(callStatus), "TRANSFER_FAILED");
}
function safeApprove(
ERC20 token,
address to,
uint256 amount
) internal {
bool callStatus;
assembly {
// Get a pointer to some free memory.
let freeMemoryPointer := mload(0x40)
// Write the abi-encoded calldata to memory piece by piece:
mstore(freeMemoryPointer, 0x095ea7b300000000000000000000000000000000000000000000000000000000) // Begin with the function selector.
mstore(add(freeMemoryPointer, 4), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "to" argument.
mstore(add(freeMemoryPointer, 36), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.
// Call the token and store if it succeeded or not.
// We use 68 because the calldata length is 4 + 32 * 2.
callStatus := call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)
}
require(didLastOptionalReturnCallSucceed(callStatus), "APPROVE_FAILED");
}
/*///////////////////////////////////////////////////////////////
INTERNAL HELPER LOGIC
//////////////////////////////////////////////////////////////*/
function didLastOptionalReturnCallSucceed(bool callStatus) private pure returns (bool success) {
assembly {
// Get how many bytes the call returned.
let returnDataSize := returndatasize()
// If the call reverted:
if iszero(callStatus) {
// Copy the revert message into memory.
returndatacopy(0, 0, returnDataSize)
// Revert with the same message.
revert(0, returnDataSize)
}
switch returnDataSize
case 32 {
// Copy the return data into memory.
returndatacopy(0, 0, returnDataSize)
// Set success to whether it returned true.
success := iszero(iszero(mload(0)))
}
case 0 {
// There was no return data.
success := 1
}
default {
// It returned some malformed output.
success := 0
}
}
}
}
/**
@title Rewards Module for Flywheel
@notice The rewards module is a minimal interface for determining the quantity of rewards accrued to a flywheel market.
Different module strategies include:
* a static reward rate per second
* a decaying reward rate
* a dynamic just-in-time reward stream
* liquid governance reward delegation
*/
interface IFlywheelRewards {
function getAccruedRewards(ERC20 market, uint32 lastUpdatedTimestamp) external returns (uint256 rewards);
}
/**
@title Flywheel Dynamic Reward Stream
@notice Determines rewards based on how many reward tokens appeared in the market itself since last accrual.
All rewards are transferred atomically, so there is no need to use the last reward timestamp.
*/
contract FlywheelDynamicRewards is IFlywheelRewards {
using SafeTransferLib for ERC20;
/// @notice the reward token paid
ERC20 public immutable rewardToken;
/// @notice the flywheel core contract
address public immutable flywheel;
constructor(ERC20 _rewardToken, address _flywheel) {
rewardToken = _rewardToken;
flywheel = _flywheel;
}
/**
@notice calculate and transfer accrued rewards to flywheel core
@param market the market to accrue rewards for
@return amount the amount of tokens accrued and transferred
*/
function getAccruedRewards(ERC20 market, uint32) external override returns (uint256 amount) {
require(msg.sender == flywheel, "!flywheel");
amount = rewardToken.balanceOf(address(market));
if (amount != 0) rewardToken.transferFrom(address(market), flywheel, amount);
}
}
{
"compilationTarget": {
"FlywheelDynamicRewards.sol": "FlywheelDynamicRewards"
},
"evmVersion": "london",
"libraries": {},
"metadata": {
"bytecodeHash": "ipfs"
},
"optimizer": {
"enabled": true,
"runs": 200
},
"remappings": []
}
[{"inputs":[{"internalType":"contract ERC20","name":"_rewardToken","type":"address"},{"internalType":"address","name":"_flywheel","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"flywheel","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"contract ERC20","name":"market","type":"address"},{"internalType":"uint32","name":"","type":"uint32"}],"name":"getAccruedRewards","outputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"rewardToken","outputs":[{"internalType":"contract ERC20","name":"","type":"address"}],"stateMutability":"view","type":"function"}]