# State

# LastTotalPower

LastTotalPower tracks the total amounts of bonded tokens recorded during the previous end block. Store entries prefixed with "Last" must remain unchanged until EndBlock.

  • LastTotalPower: 0x12 -> ProtocolBuffer(sdk.Int)

# Params

Params is a module-wide configuration structure that stores system parameters and defines overall functioning of the staking module.

  • Params: Paramsspace("staking") -> legacy_amino(params)

Copy // Params defines the parameters for the staking module. message Params { option (gogoproto.equal) = true; option (gogoproto.goproto_stringer) = false; google.protobuf.Duration unbonding_time = 1 [(gogoproto.nullable) = false, (gogoproto.stdduration) = true, (gogoproto.moretags) = "yaml:\"unbonding_time\""]; uint32 max_validators = 2 [(gogoproto.moretags) = "yaml:\"max_validators\""]; uint32 max_entries = 3 [(gogoproto.moretags) = "yaml:\"max_entries\""]; uint32 historical_entries = 4 [(gogoproto.moretags) = "yaml:\"historical_entries\""]; string bond_denom = 5 [(gogoproto.moretags) = "yaml:\"bond_denom\""]; }

# Validator

Validators can have one of three statuses

  • Unbonded: The validator is not in the active set. They cannot sign blocks and do not earn rewards. They can receive delegations.
  • Bonded": Once the validator receives sufficient bonded tokens they automtically join the active set during EndBlock and their status is updated to Bonded. They are signing blocks and receiving rewards. They can receive further delegations. They can be slashed for misbehavior. Delegators to this validator who unbond their delegation must wait the duration of the UnbondingTime, a chain-specific param, during which time they are still slashable for offences of the source validator if those offences were committed during the period of time that the tokens were bonded.
  • Unbonding: When a validator leaves the active set, either by choice or due to slashing, jailing or tombstoning, an unbonding of all their delegations begins. All delegations must then wait the UnbondingTime before their tokens are moved to their accounts from the BondedPool.

Validators objects should be primarily stored and accessed by the OperatorAddr, an SDK validator address for the operator of the validator. Two additional indices are maintained per validator object in order to fulfill required lookups for slashing and validator-set updates. A third special index (LastValidatorPower) is also maintained which however remains constant throughout each block, unlike the first two indices which mirror the validator records within a block.

  • Validators: 0x21 | OperatorAddrLen (1 byte) | OperatorAddr -> ProtocolBuffer(validator)
  • ValidatorsByConsAddr: 0x22 | ConsAddrLen (1 byte) | ConsAddr -> OperatorAddr
  • ValidatorsByPower: 0x23 | BigEndian(ConsensusPower) | OperatorAddrLen (1 byte) | OperatorAddr -> OperatorAddr
  • LastValidatorsPower: 0x11 | OperatorAddrLen (1 byte) | OperatorAddr -> ProtocolBuffer(ConsensusPower)

Validators is the primary index - it ensures that each operator can have only one associated validator, where the public key of that validator can change in the future. Delegators can refer to the immutable operator of the validator, without concern for the changing public key.

ValidatorByConsAddr is an additional index that enables lookups for slashing. When Tendermint reports evidence, it provides the validator address, so this map is needed to find the operator. Note that the ConsAddr corresponds to the address which can be derived from the validator's ConsPubKey.

ValidatorsByPower is an additional index that provides a sorted list of potential validators to quickly determine the current active set. Here ConsensusPower is validator.Tokens/10^6 by default. Note that all validators where Jailed is true are not stored within this index.

LastValidatorsPower is a special index that provides a historical list of the last-block's bonded validators. This index remains constant during a block but is updated during the validator set update process which takes place in EndBlock.

Each validator's state is stored in a Validator struct:

Copy // Validator defines a validator, together with the total amount of the // Validator's bond shares and their exchange rate to coins. Slashing results in // a decrease in the exchange rate, allowing correct calculation of future // undelegations without iterating over delegators. When coins are delegated to // this validator, the validator is credited with a delegation whose number of // bond shares is based on the amount of coins delegated divided by the current // exchange rate. Voting power can be calculated as total bonded shares // multiplied by exchange rate. message Validator { option (gogoproto.equal) = false; option (gogoproto.goproto_stringer) = false; option (gogoproto.goproto_getters) = false; string operator_address = 1 [(gogoproto.moretags) = "yaml:\"operator_address\""]; google.protobuf.Any consensus_pubkey = 2 [(cosmos_proto.accepts_interface) = "cosmos.crypto.PubKey", (gogoproto.moretags) = "yaml:\"consensus_pubkey\""]; bool jailed = 3; BondStatus status = 4; string tokens = 5 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false]; string delegator_shares = 6 [ (gogoproto.moretags) = "yaml:\"delegator_shares\"", (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false ]; Description description = 7 [(gogoproto.nullable) = false]; int64 unbonding_height = 8 [(gogoproto.moretags) = "yaml:\"unbonding_height\""]; google.protobuf.Timestamp unbonding_time = 9 [(gogoproto.nullable) = false, (gogoproto.stdtime) = true, (gogoproto.moretags) = "yaml:\"unbonding_time\""]; Commission commission = 10 [(gogoproto.nullable) = false]; string min_self_delegation = 11 [ (gogoproto.moretags) = "yaml:\"min_self_delegation\"", (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false ]; }

Copy // CommissionRates defines the initial commission rates to be used for creating // a validator. message CommissionRates { option (gogoproto.equal) = true; option (gogoproto.goproto_stringer) = false; string rate = 1 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false]; string max_rate = 2 [ (gogoproto.moretags) = "yaml:\"max_rate\"", (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false ]; string max_change_rate = 3 [ (gogoproto.moretags) = "yaml:\"max_change_rate\"", (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false ]; } // Commission defines commission parameters for a given validator. message Commission { option (gogoproto.equal) = true; option (gogoproto.goproto_stringer) = false; CommissionRates commission_rates = 1 [(gogoproto.embed) = true, (gogoproto.nullable) = false]; google.protobuf.Timestamp update_time = 2 [(gogoproto.nullable) = false, (gogoproto.stdtime) = true, (gogoproto.moretags) = "yaml:\"update_time\""]; } // Description defines a validator description. message Description { option (gogoproto.equal) = true; option (gogoproto.goproto_stringer) = false; string moniker = 1; string identity = 2; string website = 3; string security_contact = 4 [(gogoproto.moretags) = "yaml:\"security_contact\""]; string details = 5; }

# Delegation

Delegations are identified by combining DelegatorAddr (the address of the delegator) with the ValidatorAddr Delegators are indexed in the store as follows:

  • Delegation: 0x31 | DelegatorAddrLen (1 byte) | DelegatorAddr | ValidatorAddrLen (1 byte) | ValidatorAddr -> ProtocolBuffer(delegation)

Stake holders may delegate coins to validators; under this circumstance their funds are held in a Delegation data structure. It is owned by one delegator, and is associated with the shares for one validator. The sender of the transaction is the owner of the bond.

Copy // Delegation represents the bond with tokens held by an account. It is // owned by one delegator, and is associated with the voting power of one // validator. message Delegation { option (gogoproto.equal) = false; option (gogoproto.goproto_getters) = false; option (gogoproto.goproto_stringer) = false; string delegator_address = 1 [(gogoproto.moretags) = "yaml:\"delegator_address\""]; string validator_address = 2 [(gogoproto.moretags) = "yaml:\"validator_address\""]; string shares = 3 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false]; }

# Delegator Shares

When one Delegates tokens to a Validator they are issued a number of delegator shares based on a dynamic exchange rate, calculated as follows from the total number of tokens delegated to the validator and the number of shares issued so far:

Shares per Token = validator.TotalShares() / validator.Tokens()

Only the number of shares received is stored on the DelegationEntry. When a delegator then Undelegates, the token amount they receive is calculated from the number of shares they currently hold and the inverse exchange rate:

Tokens per Share = validator.Tokens() / validatorShares()

These Shares are simply an accounting mechanism. They are not a fungible asset. The reason for this mechanism is to simplify the accounting around slashing. Rather than iteratively slashing the tokens of every delegation entry, instead the Validators total bonded tokens can be slashed, effectively reducing the value of each issued delegator share.

# UnbondingDelegation

Shares in a Delegation can be unbonded, but they must for some time exist as an UnbondingDelegation, where shares can be reduced if Byzantine behavior is detected.

UnbondingDelegation are indexed in the store as:

  • UnbondingDelegation: 0x32 | DelegatorAddrLen (1 byte) | DelegatorAddr | ValidatorAddrLen (1 byte) | ValidatorAddr -> ProtocolBuffer(unbondingDelegation)
  • UnbondingDelegationsFromValidator: 0x33 | ValidatorAddrLen (1 byte) | ValidatorAddr | DelegatorAddrLen (1 byte) | DelegatorAddr -> nil

The first map here is used in queries, to lookup all unbonding delegations for a given delegator, while the second map is used in slashing, to lookup all unbonding delegations associated with a given validator that need to be slashed.

A UnbondingDelegation object is created every time an unbonding is initiated.

Copy // UnbondingDelegation stores all of a single delegator's unbonding bonds // for a single validator in an time-ordered list. message UnbondingDelegation { option (gogoproto.equal) = false; option (gogoproto.goproto_getters) = false; option (gogoproto.goproto_stringer) = false; string delegator_address = 1 [(gogoproto.moretags) = "yaml:\"delegator_address\""]; string validator_address = 2 [(gogoproto.moretags) = "yaml:\"validator_address\""]; repeated UnbondingDelegationEntry entries = 3 [(gogoproto.nullable) = false]; // unbonding delegation entries } // UnbondingDelegationEntry defines an unbonding object with relevant metadata. message UnbondingDelegationEntry { option (gogoproto.equal) = true; option (gogoproto.goproto_stringer) = false; int64 creation_height = 1 [(gogoproto.moretags) = "yaml:\"creation_height\""]; google.protobuf.Timestamp completion_time = 2 [(gogoproto.nullable) = false, (gogoproto.stdtime) = true, (gogoproto.moretags) = "yaml:\"completion_time\""]; string initial_balance = 3 [ (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false, (gogoproto.moretags) = "yaml:\"initial_balance\"" ]; string balance = 4 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false]; }

# Redelegation

The bonded tokens worth of a Delegation may be instantly redelegated from a source validator to a different validator (destination validator). However when this occurs they must be tracked in a Redelegation object, whereby their shares can be slashed if their tokens have contributed to a Byzantine fault committed by the source validator.

Redelegation are indexed in the store as:

  • Redelegations: 0x34 | DelegatorAddrLen (1 byte) | DelegatorAddr | ValidatorAddrLen (1 byte) | ValidatorSrcAddr | ValidatorDstAddr -> ProtocolBuffer(redelegation)
  • RedelegationsBySrc: 0x35 | ValidatorSrcAddrLen (1 byte) | ValidatorSrcAddr | ValidatorDstAddrLen (1 byte) | ValidatorDstAddr | DelegatorAddrLen (1 byte) | DelegatorAddr -> nil
  • RedelegationsByDst: 0x36 | ValidatorDstAddrLen (1 byte) | ValidatorDstAddr | ValidatorSrcAddrLen (1 byte) | ValidatorSrcAddr | DelegatorAddrLen (1 byte) | DelegatorAddr -> nil

The first map here is used for queries, to lookup all redelegations for a given delegator. The second map is used for slashing based on the ValidatorSrcAddr, while the third map is for slashing based on the ValidatorDstAddr.

A redelegation object is created every time a redelegation occurs. To prevent "redelegation hopping" redelegations may not occur under the situation that:

  • the (re)delegator already has another immature redelegation in progress with a destination to a validator (let's call it Validator X)
  • and, the (re)delegator is attempting to create a new redelegation where the source validator for this new redelegation is Validator X.

Copy // RedelegationEntry defines a redelegation object with relevant metadata. message RedelegationEntry { option (gogoproto.equal) = true; option (gogoproto.goproto_stringer) = false; int64 creation_height = 1 [(gogoproto.moretags) = "yaml:\"creation_height\""]; google.protobuf.Timestamp completion_time = 2 [(gogoproto.nullable) = false, (gogoproto.stdtime) = true, (gogoproto.moretags) = "yaml:\"completion_time\""]; string initial_balance = 3 [ (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false, (gogoproto.moretags) = "yaml:\"initial_balance\"" ]; string shares_dst = 4 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false]; } // Redelegation contains the list of a particular delegator's redelegating bonds // from a particular source validator to a particular destination validator. message Redelegation { option (gogoproto.equal) = false; option (gogoproto.goproto_getters) = false; option (gogoproto.goproto_stringer) = false; string delegator_address = 1 [(gogoproto.moretags) = "yaml:\"delegator_address\""]; string validator_src_address = 2 [(gogoproto.moretags) = "yaml:\"validator_src_address\""]; string validator_dst_address = 3 [(gogoproto.moretags) = "yaml:\"validator_dst_address\""]; repeated RedelegationEntry entries = 4 [(gogoproto.nullable) = false]; // redelegation entries }

# Queues

All queues objects are sorted by timestamp. The time used within any queue is first rounded to the nearest nanosecond then sorted. The sortable time format used is a slight modification of the RFC3339Nano and uses the the format string "2006-01-02T15:04:05.000000000". Notably this format:

  • right pads all zeros
  • drops the time zone info (uses UTC)

In all cases, the stored timestamp represents the maturation time of the queue element.

# UnbondingDelegationQueue

For the purpose of tracking progress of unbonding delegations the unbonding delegations queue is kept.

  • UnbondingDelegation: 0x41 | format(time) -> []DVPair

Copy // DVPair is struct that just has a delegator-validator pair with no other data. // It is intended to be used as a marshalable pointer. For example, a DVPair can // be used to construct the key to getting an UnbondingDelegation from state. message DVPair { option (gogoproto.equal) = false; option (gogoproto.goproto_getters) = false; option (gogoproto.goproto_stringer) = false; string delegator_address = 1 [(gogoproto.moretags) = "yaml:\"delegator_address\""]; string validator_address = 2 [(gogoproto.moretags) = "yaml:\"validator_address\""]; }

# RedelegationQueue

For the purpose of tracking progress of redelegations the redelegation queue is kept.

  • RedelegationQueue: 0x42 | format(time) -> []DVVTriplet

Copy // DVVTriplet is struct that just has a delegator-validator-validator triplet // with no other data. It is intended to be used as a marshalable pointer. For // example, a DVVTriplet can be used to construct the key to getting a // Redelegation from state. message DVVTriplet { option (gogoproto.equal) = false; option (gogoproto.goproto_getters) = false; option (gogoproto.goproto_stringer) = false; string delegator_address = 1 [(gogoproto.moretags) = "yaml:\"delegator_address\""]; string validator_src_address = 2 [(gogoproto.moretags) = "yaml:\"validator_src_address\""]; string validator_dst_address = 3 [(gogoproto.moretags) = "yaml:\"validator_dst_address\""]; }

# ValidatorQueue

For the purpose of tracking progress of unbonding validators the validator queue is kept.

  • ValidatorQueueTime: 0x43 | format(time) -> []sdk.ValAddress

The stored object as each key is an array of validator operator addresses from which the validator object can be accessed. Typically it is expected that only a single validator record will be associated with a given timestamp however it is possible that multiple validators exist in the queue at the same location.

# HistoricalInfo

HistoricalInfo objects are stored and pruned at each block such that the staking keeper persists the n most recent historical info defined by staking module parameter: HistoricalEntries.

Copy // HistoricalInfo contains header and validator information for a given block. // It is stored as part of staking module's state, which persists the `n` most // recent HistoricalInfo // (`n` is set by the staking module's `historical_entries` parameter). message HistoricalInfo { tendermint.types.Header header = 1 [(gogoproto.nullable) = false]; repeated Validator valset = 2 [(gogoproto.nullable) = false]; }

At each BeginBlock, the staking keeper will persist the current Header and the Validators that committed the current block in a HistoricalInfo object. The Validators are sorted on their address to ensure that they are in a determisnistic order. The oldest HistoricalEntries will be pruned to ensure that there only exist the parameter-defined number of historical entries.