feat: support for Conway protocol parameter updates (#673)

Fixes #592

Author: agaffney

ledger/conway.go

@@ -206,6 +206,55 @@ func (b *ConwayTransactionBody) Donation() uint64 {
 	return b.TxDonation
 }
 
+type ConwayProtocolParameters struct {
+	BabbageProtocolParameters
+	PoolVotingThresholds       PoolVotingThresholds
+	DRepVotingThresholds       DRepVotingThresholds
+	MinCommitteeSize           uint
+	CommitteeTermLimit         uint64
+	GovActionValidityPeriod    uint64
+	GovActionDeposit           uint64
+	DRepDeposit                uint64
+	DRepInactivityPeriod       uint64
+	MinFeeRefScriptCostPerByte *cbor.Rat
+}
+
+type ConwayProtocolParameterUpdate struct {
+	BabbageProtocolParameterUpdate
+	PoolVotingThresholds       PoolVotingThresholds `cbor:"25,keyasint"`
+	DRepVotingThresholds       DRepVotingThresholds `cbor:"26,keyasint"`
+	MinCommitteeSize           uint                 `cbor:"27,keyasint"`
+	CommitteeTermLimit         uint64               `cbor:"28,keyasint"`
+	GovActionValidityPeriod    uint64               `cbor:"29,keyasint"`
+	GovActionDeposit           uint64               `cbor:"30,keyasint"`
+	DRepDeposit                uint64               `cbor:"31,keyasint"`
+	DRepInactivityPeriod       uint64               `cbor:"32,keyasint"`
+	MinFeeRefScriptCostPerByte *cbor.Rat            `cbor:"33,keyasint"`
+}
+
+type PoolVotingThresholds struct {
+	cbor.StructAsArray
+	MotionNoConfidence                       cbor.Rat
+	CommitteeNormal                          cbor.Rat
+	CommitteeNoConfidence                    cbor.Rat
+	HardForkInitiation                       cbor.Rat
+	SecurityRelevantParameterVotingThreshold cbor.Rat
+}
+
+type DRepVotingThresholds struct {
+	cbor.StructAsArray
+	MotionNoConfidence    cbor.Rat
+	CommitteeNormal       cbor.Rat
+	CommitteeNoConfidence cbor.Rat
+	UpdateConstitution    cbor.Rat
+	HardForkInitiation    cbor.Rat
+	PPNetworkGroup        cbor.Rat
+	PPEconomicGroup       cbor.Rat
+	PPTechnicalGroup      cbor.Rat
+	PPGovGroup            cbor.Rat
+	TreasureWithdrawal    cbor.Rat
+}
+
 // VotingProcedures is a convenience type to avoid needing to duplicate the full type definition everywhere
 type VotingProcedures map[*Voter]map[*GovActionId]VotingProcedure
 
@@ -316,7 +365,7 @@ type ParameterChangeGovAction struct {
 	cbor.StructAsArray
 	Type        uint
 	ActionId    *GovActionId
-	ParamUpdate BabbageProtocolParameterUpdate // TODO: use Conway params update type
+	ParamUpdate ConwayProtocolParameterUpdate
 	PolicyHash  []byte
 }
 

protocol/localstatequery/client.go

@@ -348,6 +348,12 @@ func (c *Client) GetCurrentProtocolParams() (CurrentProtocolParamsResult, error)
 		QueryTypeShelleyCurrentProtocolParams,
 	)
 	switch currentEra {
+	case ledger.EraIdConway:
+		result := []ledger.ConwayProtocolParameters{}
+		if err := c.runQuery(query, &result); err != nil {
+			return nil, err
+		}
+		return result[0], nil
 	case ledger.EraIdBabbage:
 		result := []ledger.BabbageProtocolParameters{}
 		if err := c.runQuery(query, &result); err != nil {
@@ -379,11 +385,7 @@ func (c *Client) GetCurrentProtocolParams() (CurrentProtocolParamsResult, error)
 		}
 		return result[0], nil
 	default:
-		result := []any{}
-		if err := c.runQuery(query, &result); err != nil {
-			return nil, err
-		}
-		return result[0], nil
+		return nil, fmt.Errorf("unknown era ID: %d", currentEra)
 	}
 }