cosmos-sdk/docs/spec/governance/state.md

Implementation (1/2)

State

Procedures and base types

Procedures define the rule according to which votes are run. There can only be one active procedure at any given time. If governance wants to change a procedure, either to modify a value or add/remove a parameter, a new procedure has to be created and the previous one rendered inactive.

type DepositProcedure struct {
  MinDeposit        sdk.Coins           //  Minimum deposit for a proposal to enter voting period. 
  MaxDepositPeriod  int64               //  Maximum period for Atom holders to deposit on a proposal. Initial value: 2 months
}

type VotingProcedure struct {
  VotingPeriod      int64               //  Length of the voting period. Initial value: 2 weeks
}

type TallyingProcedure struct {
  Threshold         rational.Rational   //  Minimum propotion of Yes votes for proposal to pass. Initial value: 0.5
  Veto              rational.Rational   //  Minimum proportion of Veto votes to Total votes ratio for proposal to be vetoed. Initial value: 1/3
  GovernancePenalty sdk.Rat             //  Penalty if validator does not vote
  GracePeriod       int64               //  If validator entered validator set in this period of blocks before vote ended, governance penalty does not apply
}

Procedures are stored in a global GlobalParams KVStore.

Additionally, we introduce some basic types:

type Vote byte

const (
    VoteYes         = 0x1
    VoteNo          = 0x2
    VoteNoWithVeto  = 0x3
    VoteAbstain     = 0x4
)

type ProposalType  byte

const (
    ProposalTypePlainText       = 0x1 // Plain text proposals
    ProposalTypeSoftwareUpgrade = 0x2 // Text proposal inducing a software upgrade
)

type ProposalStatus byte


const (
    ProposalStatusOpen      = 0x1   // Proposal is submitted. Participants can deposit on it but not vote
    ProposalStatusActive    = 0x2   // MinDeposit is reachhed, participants can vote
    ProposalStatusAccepted  = 0x3   // Proposal has been accepted
    ProposalStatusRejected  = 0x4   // Proposal has been rejected
    ProposalStatusClosed.   = 0x5   // Proposal never reached MinDeposit 
)

Deposit

  type Deposit struct {
    Amount      sdk.Coins       //  Amount of coins deposited by depositer
    Depositer   crypto.address  //  Address of depositer
  }

ValidatorGovInfo

This type is used in a temp map when tallying

  type ValidatorGovInfo struct {
    Minus     sdk.Rat
    Vote      Vote
  }

Proposals

Proposals are an item to be voted on.

type Proposal struct {
  Title                 string              //  Title of the proposal
  Description           string              //  Description of the proposal
  Type                  ProposalType        //  Type of proposal. Initial set {PlainTextProposal, SoftwareUpgradeProposal}
  TotalDeposit          sdk.Coins           //  Current deposit on this proposal. Initial value is set at InitialDeposit
  Deposits              []Deposit           //  List of deposits on the proposal
  SubmitBlock           int64               //  Height of the block where TxGovSubmitProposal was included
  Submitter             sdk.Address      //  Address of the submitter
  
  VotingStartBlock      int64               //  Height of the block where MinDeposit was reached. -1 if MinDeposit is not reached
  CurrentStatus         ProposalStatus      //  Current status of the proposal

  YesVotes              sdk.Rat
  NoVotes               sdk.Rat
  NoWithVetoVotes       sdk.Rat
  AbstainVotes          sdk.Rat
}

We also mention a method to update the tally for a given proposal:

  func (proposal Proposal) updateTally(vote byte, amount sdk.Rat)

Stores

Stores are KVStores in the multistore. The key to find the store is the first parameter in the list`

We will use one KVStore Governance to store two mappings:

• A mapping from proposalID|'proposal' to Proposal
• A mapping from proposalID|'addresses'|address to Vote. This mapping allows us to query all addresses that voted on the proposal along with their vote by doing a range query on proposalID:addresses

For pseudocode purposes, here are the two function we will use to read or write in stores:

• load(StoreKey, Key): Retrieve item stored at key Key in store found at key StoreKey in the multistore
• store(StoreKey, Key, value): Write value Value at key Key in store found at key StoreKey in the multistore

Proposal Processing Queue

Store:

• ProposalProcessingQueue: A queue queue[proposalID] containing all the ProposalIDs of proposals that reached MinDeposit. Each round, the oldest element of ProposalProcessingQueue is checked during BeginBlock to see if CurrentBlock == VotingStartBlock + activeProcedure.VotingPeriod. If it is, then the application tallies the votes, compute the votes of each validator and checks if every validator in the valdiator set have voted and, if not, applies GovernancePenalty. If the proposal is accepted, deposits are refunded. After that proposal is ejected from ProposalProcessingQueue and the next element of the queue is evaluated.

And the pseudocode for the ProposalProcessingQueue:

  in EndBlock do 
    
    checkProposal()  // First call of the recursive function 
    
    
  // Recursive function. First call in BeginBlock
  func checkProposal()  
    proposalID = ProposalProcessingQueue.Peek()
    if (proposalID == nil)
      return

    proposal = load(Governance, <proposalID|'proposal'>) // proposal is a const key
    votingProcedure = load(GlobalParams, 'VotingProcedure')

    if (CurrentBlock == proposal.VotingStartBlock + votingProcedure.VotingPeriod && proposal.CurrentStatus == ProposalStatusActive)

    // End of voting period, tally

      ProposalProcessingQueue.pop()
      validators = 


      Keeper.getAllValidators()
      tmpValMap := map(sdk.Address)ValidatorGovInfo

      // Initiate mapping at 0. Validators that remain at 0 at the end of tally will be punished
      for each validator in validators
        tmpValMap(validator).Minus = 0



      // Tally
      voterIterator = rangeQuery(Governance, <proposalID|'addresses'>) //return all the addresses that voted on the proposal
      for each (voterAddress, vote) in voterIterator
        delegations = stakeKeeper.getDelegations(voterAddress) // get all delegations for current voter

        for each delegation in delegations
          // make sure delegation.Shares does NOT include shares being unbonded
          tmpValMap(delegation.ValidatorAddr).Minus += delegation.Shares
          proposal.updateTally(vote, delegation.Shares)

        _, isVal = stakeKeeper.getValidator(voterAddress)
        if (isVal)
          tmpValMap(voterAddress).Vote = vote

      tallyingProcedure = load(GlobalParams, 'TallyingProcedure')

      // Slash validators that did not vote, or update tally if they voted
      for each validator in validators
        if (validator.bondHeight < CurrentBlock - tallyingProcedure.GracePeriod)
        // only slash if validator entered validator set before grace period
          if (!tmpValMap(validator).HasVoted)
            slash validator by tallyingProcedure.GovernancePenalty
          else
            proposal.updateTally(tmpValMap(validator).Vote, (validator.TotalShares - tmpValMap(validator).Minus))



      // Check if proposal is accepted or rejected
      totalNonAbstain := proposal.YesVotes + proposal.NoVotes + proposal.NoWithVetoVotes
      if (proposal.Votes.YesVotes/totalNonAbstain > tallyingProcedure.Threshold AND proposal.Votes.NoWithVetoVotes/totalNonAbstain  < tallyingProcedure.Veto)
        //  proposal was accepted at the end of the voting period
        //  refund deposits (non-voters already punished)
        proposal.CurrentStatus = ProposalStatusAccepted
        for each (amount, depositer) in proposal.Deposits
          depositer.AtomBalance += amount

      else 
        // proposal was rejected
        proposal.CurrentStatus = ProposalStatusRejected

      store(Governance, <proposalID|'proposal'>, proposal)
      checkProposal()