6.9 KiB
status-waku-voting/contracts
Status white label proposal contract
Voting Contract
Voting contract is a smart contract created for purpose of having smart contract that can create and save results of proposals.
This Contract is responsible for creating voting rooms in which you can vote for or against them.
Lifecycle of voting room: 1. initialize voting room. 2. period of time when votes are accepted. 3. voting time is finished votes are no longer accepted.
Types
Main types used for voting are:
-
VotingRoom
Is a type that hold information about voting room for a given proposal
Fields
// block at which room was created uint256 startBlock; // timestamp in seconds after which new votes won't be accepted // when casting votes endAt is compared to block.timestamp uint256 endAt; // question of a proposal which voting room describes string question; // description for proposal string description; // amount of summed votes for uint256 totalVotesFor; // amount of summed votes against uint256 totalVotesAgainst; // list of addresses that already voted address[] voters;
-
Vote
Is a type that hold information about vote for a given voting room
Fields
//address of a voter address voter; // encoded roomId and type // first bit this field is a vote type: // 1 is a vote for // 0 is a vote against // rest of this field is a roomId shifted one bit to // the left uint256 roomIdAndType; // amount of token used to vote uint256 tokenAmount; //signature of vote bytes32 r; bytes32 vs;
Constants and variables
-
token
Variable that holds address of token used for vote verification. It is assigned at contract creation. -
votingLength
Variable describing length of voting room in seconds Voting length it is assigned at contract creation. -
EIP712DOMAIN_TYPEHASH
Constant holding type hash of EIP712 domain as per EIP712 specification -
VOTE_TYPEHASH
Constant holding type hash of Vote as per EIP712 specification -
DOMAIN_SEPARATOR
Variable holding hash of domain separator according to EIP712 spec. Assigned at smart contract creation. -
voted
this variable holds information if given address voted in a given voting room. So it is a mapping of room id to mapping of addresses to bools which say whether or not given address voted. -
votingRooms
Array that holds all voting rooms. roomId of voting room is equivalent to its index in array
Signing with EIP712
This smart contract uses EIP712 for signing vote msg. The structure of typed data for vote messages is as follows:
{
types: {
EIP712Domain: [
{ name: 'name', type: 'string' },
{ name: 'version', type: 'string' },
{ name: 'chainId', type: 'uint256' },
{ name: 'verifyingContract', type: 'address' },
],
Vote: [
{ name: 'roomIdAndType', type: 'uint256' },
{ name: 'tokenAmount', type: 'uint256' },
{ name: 'voter', type: 'address' },
],
},
primaryType: 'Vote',
domain: {
name: 'Voting Contract',
version: '1',
chainId: chainId,
verifyingContract: contract.address,
},
message: {
voter: voterAddress,
tokenAmount: tokenAmount,
roomIdAndType: roomIdAndType
}
}
For more information about EIP-712 go to docs
Functions
-
constructor(IERC20 _address)
Assigns_address
totoken
and generatesDOMAIN_SEPARATOR
-
getVotingRooms()
Returns votingRooms -
getOngoingVotingRooms()
Returns votingRooms in whichroom.endAt > block.timestamp
which means the rooms are still accepting votes. SincevotingLength
is set at contract creation and never changed,room.endAt
is never decreasing with increasing index of votingRoom. Therefore it is enough to check from votingRooms.length up to first element whichendAt < block.timestamp
-
listRoomVoters(uint256 roomId)
Returns a list of voters for a given voting room. Reverts if roomId doesn't exist. -
initializeVotingRoom(string calldata question,string calldata description,uint256 voteAmount)
Creates a new voting room with vote for set to voteAmount. First checks if voter has enough tokens to set vote for. Then creates a new voting room.startBlock
is set as current block number.endAt
is set a current block timestamp plus.votingLength
.question
is set as argumentquestion
.description
is set as argumentdescription
.totalVotesFor
is set as argumentvoteAmount
. Mappingvoted
of new voting room id ofmsg.sender
is set to true to reflect that message sender has voted on this voting room withvoteAmount
.votingRooms
are appended with newVotingRoom andvoters
in this new appended element are appended with message sender. After room initVotingRoomStarted
is emitted. -
verify(Vote calldata vote,bytes32 r,bytes32 vs)
Function used to verify thatvote
was signed byvote.voter
as per EIP712 specification. See docs for more info. -
updateRoomVotes(Vote calldata vote, uint256 roomId)
Sets totalVotes amount of voting room with index corresponding toroomId
.If voting first bit of
vote.roomIdAndType
is 1 that means that vote is for andvote.tokenAmount
is added tovotingRooms[roomId].totalVotesFor
, otherwise ifvote.roomIdAndType
is 0vote.tokenAmount
is added tovotingRooms[roomId].totalVotesAgainst
.After that add new address to room
voters
and updates mappingvoted
accordingly. -
castVotes(Vote[] calldata votes)
Function used to cast votes in rooms. Function accepts an array of votes of typeVote
.All votes are looped through and verified that votes are:
- properly signed
- voter has enough tokens to vote
- voting room exists
- voting room hasn't been closed
Vote verification is as follows. First roomId is decoded from
vote.roomIdAndType
which means shifting it to the right once.Then it is verified that voting room with given roomId exists and isn't closed if not whole function reverts, this is to discourage grouping votes for different voting rooms together (! maybe it should be changed so that votes for multiple voting rooms can be cast ? !).
After that it is verified that
vote
has been signed byvote.voter
. If not function goes to another vote in array (IDEA: maybe vote verification failed should be emitted ?).Then it is checked that
vote.voter
didn't vote in this vote room before if he did function goes to another voter (IDEA: emit alreadyVoted ?).Last check is whether
vote.voter
has enough tokens to vote. If he does notNotEnoughToken
is emitted and function goes to another voter. If he does voting room is updated withupdateRoomVotes
andVoteCast
is emitted.