cosmos-sdk/x/gov/spec/02_state.md

7.9 KiB

State

Proposals

Proposal objects are used to tally votes and generally track the proposal's state. They contain an array of arbitrary sdk.Msg's which the governance module will attempt to resolve and then execute if the proposal passes. Proposal's are identified by a unique id and contains a series of timestamps: submit_time, deposit_end_time, voting_start_time, voting_end_time which track the lifecycle of a proposal

+++ 4a129832eb/proto/cosmos/gov/v1beta2/gov.proto (L42-L52)

A proposal will generally require more than just a set of messages to explain its purpose but need some greater justification and allow a means for interested participants to discuss and debate the proposal. In most cases, it is encouraged to have an off-chain system that supports the on-chain governance process. To accommodate for this, a proposal contains a special metadata field, an array of bytes, which can be used to add context to the proposal. The metadata field allows custom use for networks, however, it is expected that the field contain a URL or some form of CID using a system such as IPFS. To support the case of interoperability across networks, the SDK recommends that the metadata represents the following JSON template:

{
  "title": "...",
  "description": "...",
  "forum": "...", // a link to the discussion platform (i.e. Discord)
  "other": "..." // any extra data that doesn't correspond to the other fields
}

This makes it far easier for clients to support multiple networks.

Writing a module that uses governance

There are many aspects of a chain, or of the individual modules that you may want to use governance to perform such as changing various parameters. This is very simple to do. First, write out your message types and MsgServer implementation. Add an authority field to the keeper which will be populated in the constructor with the governance module account: govKeeper.GetGovernanceAccount().GetAddress(). Then for the methods in the msg_server.go, perform a check on the message that the signer matches authority. This will prevent any user from executing that message.

Parameters and base types

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

DepositParams

+++ https://github.com/cosmos/cosmos-sdk/blob/v0.40.0/proto/cosmos/gov/v1beta1/gov.proto#L127-L145

VotingParams

+++ https://github.com/cosmos/cosmos-sdk/blob/v0.40.0/proto/cosmos/gov/v1beta1/gov.proto#L147-L156

TallyParams

+++ https://github.com/cosmos/cosmos-sdk/blob/v0.40.0/proto/cosmos/gov/v1beta1/gov.proto#L158-L183

Parameters 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  string

const (
    ProposalTypePlainText       = "Text"
    ProposalTypeSoftwareUpgrade = "SoftwareUpgrade"
)

type ProposalStatus byte


const (
	StatusNil           ProposalStatus = 0x00
    StatusDepositPeriod ProposalStatus = 0x01  // Proposal is submitted. Participants can deposit on it but not vote
    StatusVotingPeriod  ProposalStatus = 0x02  // MinDeposit is reached, participants can vote
    StatusPassed        ProposalStatus = 0x03  // Proposal passed and successfully executed
    StatusRejected      ProposalStatus = 0x04  // Proposal has been rejected
    StatusFailed        ProposalStatus = 0x05  // Proposal passed but failed execution
)

Deposit

+++ https://github.com/cosmos/cosmos-sdk/blob/v0.40.0/proto/cosmos/gov/v1beta1/gov.proto#L43-L53

ValidatorGovInfo

This type is used in a temp map when tallying

  type ValidatorGovInfo struct {
    Minus     sdk.Dec
    Vote      Vote
  }

Stores

Stores are KVStores in the multi-store. 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. During each EndBlock, all the proposals that have reached the end of their voting period are processed. To process a finished proposal, the application tallies the votes, computes the votes of each validator and checks if every validator in the validator set has voted. If the proposal is accepted, deposits are refunded. Finally, the proposal content Handler is executed.

And the pseudocode for the ProposalProcessingQueue:

  in EndBlock do

    for finishedProposalID in GetAllFinishedProposalIDs(block.Time)
      proposal = load(Governance, <proposalID|'proposal'>) // proposal is a const key

      validators = Keeper.getAllValidators()
      tmpValMap := map(sdk.AccAddress)ValidatorGovInfo

      // Initiate mapping at 0. This is the amount of shares of the validator's vote that will be overridden by their delegator's votes
      for each validator in validators
        tmpValMap(validator.OperatorAddr).Minus = 0

      // Tally
      voterIterator = rangeQuery(Governance, <proposalID|'addresses'>) //return all the addresses that voted on the proposal
      for each (voterAddress, vote) in voterIterator
        delegations = stakingKeeper.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 = stakingKeeper.getValidator(voterAddress)
        if (isVal)
          tmpValMap(voterAddress).Vote = vote

      tallyingParam = load(GlobalParams, 'TallyingParam')

      // Update tally if validator voted they voted
      for each validator in validators
        if tmpValMap(validator).HasVoted
          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 > tallyingParam.Threshold AND proposal.Votes.NoWithVetoVotes/totalNonAbstain  < tallyingParam.Veto)
        //  proposal was accepted at the end of the voting period
        //  refund deposits (non-voters already punished)
        for each (amount, depositor) in proposal.Deposits
          depositor.AtomBalance += amount

        stateWriter, err := proposal.Handler()
        if err != nil
            // proposal passed but failed during state execution
            proposal.CurrentStatus = ProposalStatusFailed
         else
            // proposal pass and state is persisted
            proposal.CurrentStatus = ProposalStatusAccepted
            stateWriter.save()
      else
        // proposal was rejected
        proposal.CurrentStatus = ProposalStatusRejected

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