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Add governance contracts (Bravo)

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393
contracts/GovernorBravoDelegate.sol Normal file
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pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import {
GovernorBravoDelegateStorageV1,
GovernorBravoEvents,
TimelockInterface,
TokenInterface
} from "./GovernorBravoInterfaces.sol";
import { SafeMath } from "./SafeMath.sol";
contract GovernorBravoDelegate is GovernorBravoDelegateStorageV1, GovernorBravoEvents {
/// @notice The name of this contract
string public constant name = "DSL Governor Bravo";
/// @notice The minimum setable proposal threshold
uint public constant MIN_PROPOSAL_THRESHOLD = 50000e18; // TODO - Update this
/// @notice The maximum setable proposal threshold
uint public constant MAX_PROPOSAL_THRESHOLD = 100000e18; // TODO - Update this
/// @notice The minimum setable voting period
uint public constant MIN_VOTING_PERIOD = 5760; // About 24 hours
/// @notice The max setable voting period
uint public constant MAX_VOTING_PERIOD = 80640; // About 2 weeks
/// @notice The min setable voting delay
uint public constant MIN_VOTING_DELAY = 1;
/// @notice The max setable voting delay
uint public constant MAX_VOTING_DELAY = 40320; // About 1 week
/// @notice The number of votes in support of a proposal required in order for a quorum to be reached and for a vote to succeed
uint public constant quorumVotes = 400000e18; // TODO - Update this
/// @notice The maximum number of actions that can be included in a proposal
uint public constant proposalMaxOperations = 10; // 10 actions
/// @notice The EIP-712 typehash for the contract's domain
bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
/// @notice The EIP-712 typehash for the ballot struct used by the contract
bytes32 public constant BALLOT_TYPEHASH = keccak256("Ballot(uint256 proposalId,uint8 support)");
/**
* @notice Used to initialize the contract during delegator contructor
* @param timelock_ The address of the Timelock
* @param token_ The address of the DSL Governance Token
* @param votingPeriod_ The initial voting period
* @param votingDelay_ The initial voting delay
* @param proposalThreshold_ The initial proposal threshold
*/
function initialize(address timelock_, address token_, uint votingPeriod_, uint votingDelay_, uint proposalThreshold_) public {
require(address(timelock) == address(0), "GovernorBravo::initialize: can only initialize once");
require(msg.sender == admin, "GovernorBravo::initialize: admin only");
require(timelock_ != address(0), "GovernorBravo::initialize: invalid timelock address");
require(token_ != address(0), "GovernorBravo::initialize: invalid comp address");
require(votingPeriod_ >= MIN_VOTING_PERIOD && votingPeriod_ <= MAX_VOTING_PERIOD, "GovernorBravo::initialize: invalid voting period");
require(votingDelay_ >= MIN_VOTING_DELAY && votingDelay_ <= MAX_VOTING_DELAY, "GovernorBravo::initialize: invalid voting delay");
require(proposalThreshold_ >= MIN_PROPOSAL_THRESHOLD && proposalThreshold_ <= MAX_PROPOSAL_THRESHOLD, "GovernorBravo::initialize: invalid proposal threshold");
timelock = TimelockInterface(timelock_);
token = TokenInterface(token_);
votingPeriod = votingPeriod_;
votingDelay = votingDelay_;
proposalThreshold = proposalThreshold_;
}
/**
* @notice Function used to propose a new proposal. Sender must have delegates above the proposal threshold
* @param targets Target addresses for proposal calls
* @param values Eth values for proposal calls
* @param signatures Function signatures for proposal calls
* @param calldatas Calldatas for proposal calls
* @param description String description of the proposal
* @return Proposal id of new proposal
*/
function propose(address[] memory targets, uint[] memory values, string[] memory signatures, bytes[] memory calldatas, string memory description) public returns (uint) {
require(token.getPriorVotes(msg.sender, SafeMath.sub(block.number, 1)) > proposalThreshold, "GovernorBravo::propose: proposer votes below proposal threshold");
require(targets.length == values.length && targets.length == signatures.length && targets.length == calldatas.length, "GovernorBravo::propose: proposal function information arity mismatch");
require(targets.length != 0, "GovernorBravo::propose: must provide actions");
require(targets.length <= proposalMaxOperations, "GovernorBravo::propose: too many actions");
uint latestProposalId = latestProposalIds[msg.sender];
if (latestProposalId != 0) {
ProposalState proposersLatestProposalState = state(latestProposalId);
require(proposersLatestProposalState != ProposalState.Active, "GovernorBravo::propose: one live proposal per proposer, found an already active proposal");
require(proposersLatestProposalState != ProposalState.Pending, "GovernorBravo::propose: one live proposal per proposer, found an already pending proposal");
}
uint startBlock = SafeMath.add(block.number, votingDelay);
uint endBlock = SafeMath.add(startBlock, votingPeriod);
proposalCount++;
// Proposal memory newProposal = Proposal({
// id: proposalCount,
// proposer: msg.sender,
// eta: 0,
// targets: targets,
// values: values,
// signatures: signatures,
// calldatas: calldatas,
// startBlock: startBlock,
// endBlock: endBlock,
// forVotes: 0,
// againstVotes: 0,
// abstainVotes: 0,
// canceled: false,
// executed: false
// });
Proposal storage newProposal = proposals[proposalCount];
newProposal.id = proposalCount;
newProposal.proposer = msg.sender;
newProposal.targets = targets;
newProposal.values = values;
newProposal.signatures = signatures;
newProposal.calldatas = calldatas;
newProposal.startBlock = startBlock;
newProposal.endBlock = endBlock;
latestProposalIds[newProposal.proposer] = proposalCount;
emit ProposalCreated(proposalCount, msg.sender, targets, values, signatures, calldatas, startBlock, endBlock, description);
return proposalCount;
}
/**
* @notice Queues a proposal of state succeeded
* @param proposalId The id of the proposal to queue
*/
function queue(uint proposalId) external {
require(state(proposalId) == ProposalState.Succeeded, "GovernorBravo::queue: proposal can only be queued if it is succeeded");
Proposal storage proposal = proposals[proposalId];
uint eta = SafeMath.add(block.timestamp, timelock.delay());
for (uint i = 0; i < proposal.targets.length; i++) {
queueOrRevertInternal(proposal.targets[i], proposal.values[i], proposal.signatures[i], proposal.calldatas[i], eta);
}
proposal.eta = eta;
emit ProposalQueued(proposalId, eta);
}
function queueOrRevertInternal(address target, uint value, string memory signature, bytes memory data, uint eta) internal {
require(!timelock.queuedTransactions(keccak256(abi.encode(target, value, signature, data, eta))), "GovernorBravo::queueOrRevertInternal: identical proposal action already queued at eta");
timelock.queueTransaction(target, value, signature, data, eta);
}
/**
* @notice Executes a queued proposal if eta has passed
* @param proposalId The id of the proposal to execute
*/
function execute(uint proposalId) external payable {
require(state(proposalId) == ProposalState.Queued, "GovernorBravo::execute: proposal can only be executed if it is queued");
Proposal storage proposal = proposals[proposalId];
proposal.executed = true;
for (uint i = 0; i < proposal.targets.length; i++) {
timelock.executeTransaction{value: proposal.values[i]}(proposal.targets[i], proposal.values[i], proposal.signatures[i], proposal.calldatas[i], proposal.eta);
}
emit ProposalExecuted(proposalId);
}
/**
* @notice Cancels a proposal only if sender is the proposer, or proposer delegates dropped below proposal threshold
* @param proposalId The id of the proposal to cancel
*/
function cancel(uint proposalId) external {
require(state(proposalId) != ProposalState.Executed, "GovernorBravo::cancel: cannot cancel executed proposal");
Proposal storage proposal = proposals[proposalId];
require(msg.sender == proposal.proposer || token.getPriorVotes(proposal.proposer, SafeMath.sub(block.number, 1)) < proposalThreshold, "GovernorBravo::cancel: proposer above threshold");
proposal.canceled = true;
for (uint i = 0; i < proposal.targets.length; i++) {
timelock.cancelTransaction(proposal.targets[i], proposal.values[i], proposal.signatures[i], proposal.calldatas[i], proposal.eta);
}
emit ProposalCanceled(proposalId);
}
/**
* @notice Gets actions of a proposal
* @param proposalId the id of the proposal
* @return targets
* @return values
* @return signatures
* @return calldatas
*/
function getActions(uint proposalId) external view returns (address[] memory targets, uint[] memory values, string[] memory signatures, bytes[] memory calldatas) {
Proposal storage p = proposals[proposalId];
return (p.targets, p.values, p.signatures, p.calldatas);
}
/**
* @notice Gets the receipt for a voter on a given proposal
* @param proposalId the id of proposal
* @param voter The address of the voter
* @return The voting receipt
*/
function getReceipt(uint proposalId, address voter) external view returns (Receipt memory) {
return proposals[proposalId].receipts[voter];
}
/**
* @notice Gets the state of a proposal
* @param proposalId The id of the proposal
* @return Proposal state
*/
function state(uint proposalId) public view returns (ProposalState) {
require(proposalCount >= proposalId, "GovernorBravo::state: invalid proposal id");
Proposal storage proposal = proposals[proposalId];
if (proposal.canceled) {
return ProposalState.Canceled;
} else if (block.number <= proposal.startBlock) {
return ProposalState.Pending;
} else if (block.number <= proposal.endBlock) {
return ProposalState.Active;
} else if (proposal.forVotes <= proposal.againstVotes || proposal.forVotes < quorumVotes) {
return ProposalState.Defeated;
} else if (proposal.eta == 0) {
return ProposalState.Succeeded;
} else if (proposal.executed) {
return ProposalState.Executed;
} else if (block.timestamp >= SafeMath.add(proposal.eta, timelock.GRACE_PERIOD())) {
return ProposalState.Expired;
} else {
return ProposalState.Queued;
}
}
/**
* @notice Cast a vote for a proposal
* @param proposalId The id of the proposal to vote on
* @param support The support value for the vote. 0=against, 1=for, 2=abstain
*/
function castVote(uint proposalId, uint8 support) external {
emit VoteCast(msg.sender, proposalId, support, castVoteInternal(msg.sender, proposalId, support), "");
}
/**
* @notice Cast a vote for a proposal with a reason
* @param proposalId The id of the proposal to vote on
* @param support The support value for the vote. 0=against, 1=for, 2=abstain
* @param reason The reason given for the vote by the voter
*/
function castVoteWithReason(uint proposalId, uint8 support, string calldata reason) external {
emit VoteCast(msg.sender, proposalId, support, castVoteInternal(msg.sender, proposalId, support), reason);
}
/**
* @notice Cast a vote for a proposal by signature
* @dev External function that accepts EIP-712 signatures for voting on proposals.
*/
function castVoteBySig(uint proposalId, uint8 support, uint8 v, bytes32 r, bytes32 s) external {
bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), getChainIdInternal(), address(this)));
bytes32 structHash = keccak256(abi.encode(BALLOT_TYPEHASH, proposalId, support));
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != address(0), "GovernorBravo::castVoteBySig: invalid signature");
emit VoteCast(signatory, proposalId, support, castVoteInternal(signatory, proposalId, support), "");
}
/**
* @notice Internal function that caries out voting logic
* @param voter The voter that is casting their vote
* @param proposalId The id of the proposal to vote on
* @param support The support value for the vote. 0=against, 1=for, 2=abstain
* @return The number of votes cast
*/
function castVoteInternal(address voter, uint proposalId, uint8 support) internal returns (uint96) {
require(state(proposalId) == ProposalState.Active, "GovernorBravo::castVoteInternal: voting is closed");
require(support <= 2, "GovernorBravo::castVoteInternal: invalid vote type");
Proposal storage proposal = proposals[proposalId];
Receipt storage receipt = proposal.receipts[voter];
require(receipt.hasVoted == false, "GovernorBravo::castVoteInternal: voter already voted");
uint96 votes = token.getPriorVotes(voter, proposal.startBlock);
if (support == 0) {
proposal.againstVotes = SafeMath.add(proposal.againstVotes, votes);
} else if (support == 1) {
proposal.forVotes = SafeMath.add(proposal.forVotes, votes);
} else if (support == 2) {
proposal.abstainVotes = SafeMath.add(proposal.abstainVotes, votes);
}
receipt.hasVoted = true;
receipt.support = support;
receipt.votes = votes;
return votes;
}
/**
* @notice Admin function for setting the voting delay
* @param newVotingDelay new voting delay, in blocks
*/
function _setVotingDelay(uint newVotingDelay) external {
require(msg.sender == admin, "GovernorBravo::_setVotingDelay: admin only");
require(newVotingDelay >= MIN_VOTING_DELAY && newVotingDelay <= MAX_VOTING_DELAY, "GovernorBravo::_setVotingDelay: invalid voting delay");
uint oldVotingDelay = votingDelay;
votingDelay = newVotingDelay;
emit VotingDelaySet(oldVotingDelay,votingDelay);
}
/**
* @notice Admin function for setting the voting period
* @param newVotingPeriod new voting period, in blocks
*/
function _setVotingPeriod(uint newVotingPeriod) external {
require(msg.sender == admin, "GovernorBravo::_setVotingPeriod: admin only");
require(newVotingPeriod >= MIN_VOTING_PERIOD && newVotingPeriod <= MAX_VOTING_PERIOD, "GovernorBravo::_setVotingPeriod: invalid voting period");
uint oldVotingPeriod = votingPeriod;
votingPeriod = newVotingPeriod;
emit VotingPeriodSet(oldVotingPeriod, votingPeriod);
}
/**
* @notice Admin function for setting the proposal threshold
* @dev newProposalThreshold must be greater than the hardcoded min
* @param newProposalThreshold new proposal threshold
*/
function _setProposalThreshold(uint newProposalThreshold) external {
require(msg.sender == admin, "GovernorBravo::_setProposalThreshold: admin only");
require(newProposalThreshold >= MIN_PROPOSAL_THRESHOLD && newProposalThreshold <= MAX_PROPOSAL_THRESHOLD, "GovernorBravo::_setProposalThreshold: invalid proposal threshold");
uint oldProposalThreshold = proposalThreshold;
proposalThreshold = newProposalThreshold;
emit ProposalThresholdSet(oldProposalThreshold, proposalThreshold);
}
/**
* @notice Initiate the GovernorBravo contract
* @dev Admin only. Accepts timelock admin
*/
function _initiate() external {
require(msg.sender == admin, "GovernorBravo::_initiate: admin only");
require(proposalCount == 0, "GovernorBravo::_initiate: can only initiate once");
timelock.acceptAdmin();
}
/**
* @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer.
* @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer.
* @param newPendingAdmin New pending admin.
*/
function _setPendingAdmin(address newPendingAdmin) external {
// Check caller = admin
require(msg.sender == admin, "GovernorBravo:_setPendingAdmin: admin only");
// Save current value, if any, for inclusion in log
address oldPendingAdmin = pendingAdmin;
// Store pendingAdmin with value newPendingAdmin
pendingAdmin = newPendingAdmin;
// Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin)
emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin);
}
/**
* @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin
* @dev Admin function for pending admin to accept role and update admin
*/
function _acceptAdmin() external {
// Check caller is pendingAdmin and pendingAdmin ≠ address(0)
require(msg.sender == pendingAdmin && msg.sender != address(0), "GovernorBravo:_acceptAdmin: pending admin only");
// Save current values for inclusion in log
address oldAdmin = admin;
address oldPendingAdmin = pendingAdmin;
// Store admin with value pendingAdmin
admin = pendingAdmin;
// Clear the pending value
pendingAdmin = address(0);
emit NewAdmin(oldAdmin, admin);
emit NewPendingAdmin(oldPendingAdmin, pendingAdmin);
}
function getChainIdInternal() internal pure returns (uint) {
uint chainId;
assembly { chainId := chainid() }
return chainId;
}
}

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contracts/GovernorBravoDelegator.sol Normal file
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pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import { GovernorBravoDelegatorStorage, GovernorBravoEvents } from "./GovernorBravoInterfaces.sol";
contract GovernorBravoDelegator is GovernorBravoDelegatorStorage, GovernorBravoEvents {
constructor(
address timelock_,
address admin_,
address token_,
address implementation_,
uint votingPeriod_,
uint votingDelay_,
uint proposalThreshold_
) {
// Admin set to msg.sender for initialization
admin = msg.sender;
delegateTo(
implementation_,
abi.encodeWithSignature(
"initialize(address,address,uint256,uint256,uint256)",
timelock_,
token_,
votingPeriod_,
votingDelay_,
proposalThreshold_
)
);
_setImplementation(implementation_);
admin = admin_;
}
/**
* @notice Called by the admin to update the implementation of the delegator
* @param implementation_ The address of the new implementation for delegation
*/
function _setImplementation(address implementation_) public {
require(msg.sender == admin, "GovernorBravoDelegator::_setImplementation: admin only");
require(implementation_ != address(0), "GovernorBravoDelegator::_setImplementation: invalid implementation address");
address oldImplementation = implementation;
implementation = implementation_;
emit NewImplementation(oldImplementation, implementation);
}
/**
* @notice Internal method to delegate execution to another contract
* @dev It returns to the external caller whatever the implementation returns or forwards reverts
* @param callee The contract to delegatecall
* @param data The raw data to delegatecall
*/
function delegateTo(address callee, bytes memory data) internal {
(bool success, bytes memory returnData) = callee.delegatecall(data);
assembly {
if eq(success, 0) {
revert(add(returnData, 0x20), returndatasize())
}
}
}
/**
* @dev Delegates execution to an implementation contract.
* It returns to the external caller whatever the implementation returns
* or forwards reverts.
*/
fallback () external payable {
// delegate all other functions to current implementation
(bool success, ) = implementation.delegatecall(msg.data);
assembly {
let free_mem_ptr := mload(0x40)
returndatacopy(free_mem_ptr, 0, returndatasize())
switch success
case 0 { revert(free_mem_ptr, returndatasize()) }
default { return(free_mem_ptr, returndatasize()) }
}
}
}

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contracts/GovernorBravoInterfaces.sol Normal file
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pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
interface TimelockInterface {
function delay() external view returns (uint);
function GRACE_PERIOD() external view returns (uint);
function acceptAdmin() external;
function queuedTransactions(bytes32 hash) external view returns (bool);
function queueTransaction(address target, uint value, string calldata signature, bytes calldata data, uint eta) external returns (bytes32);
function cancelTransaction(address target, uint value, string calldata signature, bytes calldata data, uint eta) external;
function executeTransaction(address target, uint value, string calldata signature, bytes calldata data, uint eta) external payable returns (bytes memory);
}
interface TokenInterface {
function getPriorVotes(address account, uint blockNumber) external view returns (uint96);
}
contract GovernorBravoEvents {
/// @notice An event emitted when a new proposal is created
event ProposalCreated(
uint id,
address proposer,
address[] targets,
uint[] values,
string[] signatures,
bytes[] calldatas,
uint startBlock,
uint endBlock,
string description
);
/// @notice An event emitted when a vote has been cast on a proposal
/// @param voter The address which casted a vote
/// @param proposalId The proposal id which was voted on
/// @param support Support value for the vote. 0=against, 1=for, 2=abstain
/// @param votes Number of votes which were cast by the voter
/// @param reason The reason given for the vote by the voter
event VoteCast(address indexed voter, uint proposalId, uint8 support, uint votes, string reason);
/// @notice An event emitted when a proposal has been canceled
event ProposalCanceled(uint id);
/// @notice An event emitted when a proposal has been queued in the Timelock
event ProposalQueued(uint id, uint eta);
/// @notice An event emitted when a proposal has been executed in the Timelock
event ProposalExecuted(uint id);
/// @notice An event emitted when the voting delay is set
event VotingDelaySet(uint oldVotingDelay, uint newVotingDelay);
/// @notice An event emitted when the voting period is set
event VotingPeriodSet(uint oldVotingPeriod, uint newVotingPeriod);
/// @notice Emitted when implementation is changed
event NewImplementation(address oldImplementation, address newImplementation);
/// @notice Emitted when proposal threshold is set
event ProposalThresholdSet(uint oldProposalThreshold, uint newProposalThreshold);
/// @notice Emitted when pendingAdmin is changed
event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin);
/// @notice Emitted when pendingAdmin is accepted, which means admin is updated
event NewAdmin(address oldAdmin, address newAdmin);
}
contract GovernorBravoDelegatorStorage {
/// @notice Administrator for this contract
address public admin;
/// @notice Pending administrator for this contract
address public pendingAdmin;
/// @notice Active brains of Governor
address public implementation;
}
/**
* @title Storage for Governor Bravo Delegate
* @notice For future upgrades, do not change GovernorBravoDelegateStorageV1. Create a new
* contract which implements GovernorBravoDelegateStorageV1 and following the naming convention
* GovernorBravoDelegateStorageVX.
*/
contract GovernorBravoDelegateStorageV1 is GovernorBravoDelegatorStorage {
/// @notice The delay before voting on a proposal may take place, once proposed, in blocks
uint public votingDelay;
/// @notice The duration of voting on a proposal, in blocks
uint public votingPeriod;
/// @notice The number of votes required in order for a voter to become a proposer
uint public proposalThreshold;
/// @notice The total number of proposals
uint public proposalCount;
/// @notice The address of the DSL Protocol Timelock
TimelockInterface public timelock;
/// @notice The address of the DSL governance token
TokenInterface public token;
/// @notice The official record of all proposals ever proposed
mapping (uint => Proposal) public proposals;
/// @notice The latest proposal for each proposer
mapping (address => uint) public latestProposalIds;
struct Proposal {
// Unique id for looking up a proposal
uint id;
// Creator of the proposal
address proposer;
// The timestamp that the proposal will be available for execution, set once the vote succeeds
uint eta;
// the ordered list of target addresses for calls to be made
address[] targets;
// The ordered list of values (i.e. msg.value) to be passed to the calls to be made
uint[] values;
// The ordered list of function signatures to be called
string[] signatures;
// The ordered list of calldata to be passed to each call
bytes[] calldatas;
// The block at which voting begins: holders must delegate their votes prior to this block
uint startBlock;
// The block at which voting ends: votes must be cast prior to this block
uint endBlock;
// Current number of votes in favor of this proposal
uint forVotes;
// Current number of votes in opposition to this proposal
uint againstVotes;
// Current number of votes for abstaining for this proposal
uint abstainVotes;
// Flag marking whether the proposal has been canceled
bool canceled;
// Flag marking whether the proposal has been executed
bool executed;
// Receipts of ballots for the entire set of voters
mapping (address => Receipt) receipts;
}
/// @notice Ballot receipt record for a voter
struct Receipt {
// Whether or not a vote has been cast
bool hasVoted;
// Whether or not the voter supports the proposal or abstains
uint8 support;
// The number of votes the voter had, which were cast
uint96 votes;
}
/// @notice Possible states that a proposal may be in
enum ProposalState {
Pending,
Active,
Canceled,
Defeated,
Succeeded,
Queued,
Expired,
Executed
}
}

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pragma solidity ^0.7.0;
// From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/Math.sol
// Subject to the MIT license.
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the addition of two unsigned integers, reverting with custom message on overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, errorMessage);
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on underflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot underflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction underflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on underflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot underflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, errorMessage);
return c;
}
/**
* @dev Returns the integer division of two unsigned integers.
* Reverts on division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers.
* Reverts with custom message on division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}

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contracts/Timelock.sol Normal file
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pragma solidity ^0.7.0;
import "./SafeMath.sol";
contract Timelock {
using SafeMath for uint;
event NewAdmin(address indexed newAdmin);
event NewPendingAdmin(address indexed newPendingAdmin);
event NewDelay(uint indexed newDelay);
event CancelTransaction(bytes32 indexed txHash, address indexed target, uint value, string signature, bytes data, uint eta);
event ExecuteTransaction(bytes32 indexed txHash, address indexed target, uint value, string signature, bytes data, uint eta);
event QueueTransaction(bytes32 indexed txHash, address indexed target, uint value, string signature, bytes data, uint eta);
uint public constant GRACE_PERIOD = 14 days;
uint public constant MINIMUM_DELAY = 2 days;
uint public constant MAXIMUM_DELAY = 30 days;
address public admin;
address public pendingAdmin;
uint public delay;
mapping (bytes32 => bool) public queuedTransactions;
constructor(address admin_, uint delay_) {
require(delay_ >= MINIMUM_DELAY, "Timelock::constructor: Delay must exceed minimum delay.");
require(delay_ <= MAXIMUM_DELAY, "Timelock::setDelay: Delay must not exceed maximum delay.");
admin = admin_;
delay = delay_;
}
fallback() external payable { }
function setDelay(uint delay_) public {
require(msg.sender == address(this), "Timelock::setDelay: Call must come from Timelock.");
require(delay_ >= MINIMUM_DELAY, "Timelock::setDelay: Delay must exceed minimum delay.");
require(delay_ <= MAXIMUM_DELAY, "Timelock::setDelay: Delay must not exceed maximum delay.");
delay = delay_;
emit NewDelay(delay);
}
function acceptAdmin() public {
require(msg.sender == pendingAdmin, "Timelock::acceptAdmin: Call must come from pendingAdmin.");
admin = msg.sender;
pendingAdmin = address(0);
emit NewAdmin(admin);
}
function setPendingAdmin(address pendingAdmin_) public {
require(msg.sender == address(this), "Timelock::setPendingAdmin: Call must come from Timelock.");
pendingAdmin = pendingAdmin_;
emit NewPendingAdmin(pendingAdmin);
}
function queueTransaction(address target, uint value, string memory signature, bytes memory data, uint eta) public returns (bytes32) {
require(msg.sender == admin, "Timelock::queueTransaction: Call must come from admin.");
require(eta >= getBlockTimestamp().add(delay), "Timelock::queueTransaction: Estimated execution block must satisfy delay.");
bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));
queuedTransactions[txHash] = true;
emit QueueTransaction(txHash, target, value, signature, data, eta);
return txHash;
}
function cancelTransaction(address target, uint value, string memory signature, bytes memory data, uint eta) public {
require(msg.sender == admin, "Timelock::cancelTransaction: Call must come from admin.");
bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));
queuedTransactions[txHash] = false;
emit CancelTransaction(txHash, target, value, signature, data, eta);
}
function executeTransaction(address target, uint value, string memory signature, bytes memory data, uint eta) public payable returns (bytes memory) {
require(msg.sender == admin, "Timelock::executeTransaction: Call must come from admin.");
bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));
require(queuedTransactions[txHash], "Timelock::executeTransaction: Transaction hasn't been queued.");
require(getBlockTimestamp() >= eta, "Timelock::executeTransaction: Transaction hasn't surpassed time lock.");
require(getBlockTimestamp() <= eta.add(GRACE_PERIOD), "Timelock::executeTransaction: Transaction is stale.");
queuedTransactions[txHash] = false;
bytes memory callData;
if (bytes(signature).length == 0) {
callData = data;
} else {
callData = abi.encodePacked(bytes4(keccak256(bytes(signature))), data);
}
// solium-disable-next-line security/no-call-value
(bool success, bytes memory returnData) = target.call{value: value}(callData);
require(success, "Timelock::executeTransaction: Transaction execution reverted.");
emit ExecuteTransaction(txHash, target, value, signature, data, eta);
return returnData;
}
function getBlockTimestamp() internal view returns (uint) {
// solium-disable-next-line security/no-block-members
return block.timestamp;
}
}