feat: Shelley protocol param updates

* update protocol parameter set from protocol param update spec
* update protocol parameter set from genesis config
* create big.Rat wrapper for JSON unmarshal and use for genesis config
  decimal values

ledger/shelley/genesis.go

@@ -16,7 +16,9 @@ package shelley
 
 import (
 	"encoding/json"
+	"fmt"
 	"io"
+	"math/big"
 	"os"
 	"time"
 )
@@ -49,10 +51,10 @@ type ShelleyGenesisProtocolParams struct {
 	PoolDeposit        uint
 	MaxEpoch           uint `json:"eMax"`
 	NOpt               uint
-	A0                 float32
-	Rho                float32
-	Tau                float32
-	Decentralization   float32 `json:"decentralisationParam"`
+	A0                 *GenesisRat
+	Rho                *GenesisRat
+	Tau                *GenesisRat
+	Decentralization   *GenesisRat `json:"decentralisationParam"`
 	ExtraEntropy       map[string]string
 	ProtocolVersion    struct {
 		Major uint
@@ -80,3 +82,16 @@ func NewShelleyGenesisFromFile(path string) (ShelleyGenesis, error) {
 	defer f.Close()
 	return NewShelleyGenesisFromReader(f)
 }
+
+// GenesisRat is a wrapper to big.Rat that allows for unmarshaling from a bare float from JSON
+type GenesisRat struct {
+	*big.Rat
+}
+
+func (r *GenesisRat) UnmarshalJSON(data []byte) error {
+	r.Rat = new(big.Rat)
+	if _, ok := r.Rat.SetString(string(data)); !ok {
+		return fmt.Errorf("math/big: cannot unmarshal %q into a *big.Rat", data)
+	}
+	return nil
+}

ledger/shelley/genesis_test.go

@@ -15,6 +15,7 @@
 package shelley_test
 
 import (
+	"math/big"
 	"reflect"
 	"strings"
 	"testing"
@@ -125,10 +126,10 @@ var expectedGenesisObj = shelley.ShelleyGenesis{
 		PoolDeposit:        500000000,
 		MaxEpoch:           18,
 		NOpt:               150,
-		A0:                 0.3,
-		Rho:                0.003,
-		Tau:                0.2,
-		Decentralization:   1,
+		A0:                 &shelley.GenesisRat{Rat: big.NewRat(3, 10)},
+		Rho:                &shelley.GenesisRat{Rat: big.NewRat(3, 1000)},
+		Tau:                &shelley.GenesisRat{Rat: big.NewRat(2, 10)},
+		Decentralization:   &shelley.GenesisRat{Rat: new(big.Rat).SetInt64(1)},
 		ExtraEntropy: map[string]string{
 			"tag": "NeutralNonce",
 		},

ledger/shelley/pparams.go

@@ -0,0 +1,194 @@
+// Copyright 2024 Blink Labs Software
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shelley
+
+import (
+	"fmt"
+	"math/big"
+
+	"github.com/blinklabs-io/gouroboros/cbor"
+)
+
+type ShelleyProtocolParameters struct {
+	cbor.StructAsArray
+	MinFeeA            uint
+	MinFeeB            uint
+	MaxBlockBodySize   uint
+	MaxTxSize          uint
+	MaxBlockHeaderSize uint
+	KeyDeposit         uint
+	PoolDeposit        uint
+	MaxEpoch           uint
+	NOpt               uint
+	A0                 *cbor.Rat
+	Rho                *cbor.Rat
+	Tau                *cbor.Rat
+	Decentralization   *cbor.Rat
+	Nonce              *Nonce
+	ProtocolMajor      uint
+	ProtocolMinor      uint
+	MinUtxoValue       uint
+}
+
+func (p *ShelleyProtocolParameters) Update(paramUpdate *ShelleyProtocolParameterUpdate) {
+	if paramUpdate.MinFeeA != nil {
+		p.MinFeeA = *paramUpdate.MinFeeA
+	}
+	if paramUpdate.MinFeeB != nil {
+		p.MinFeeB = *paramUpdate.MinFeeB
+	}
+	if paramUpdate.MaxBlockBodySize != nil {
+		p.MaxBlockBodySize = *paramUpdate.MaxBlockBodySize
+	}
+	if paramUpdate.MaxTxSize != nil {
+		p.MaxTxSize = *paramUpdate.MaxTxSize
+	}
+	if paramUpdate.MaxBlockHeaderSize != nil {
+		p.MaxBlockHeaderSize = *paramUpdate.MaxBlockHeaderSize
+	}
+	if paramUpdate.KeyDeposit != nil {
+		p.KeyDeposit = *paramUpdate.KeyDeposit
+	}
+	if paramUpdate.PoolDeposit != nil {
+		p.PoolDeposit = *paramUpdate.PoolDeposit
+	}
+	if paramUpdate.MaxEpoch != nil {
+		p.MaxEpoch = *paramUpdate.MaxEpoch
+	}
+	if paramUpdate.NOpt != nil {
+		p.NOpt = *paramUpdate.NOpt
+	}
+	if paramUpdate.A0 != nil {
+		p.A0 = paramUpdate.A0
+	}
+	if paramUpdate.Rho != nil {
+		p.Rho = paramUpdate.Rho
+	}
+	if paramUpdate.Tau != nil {
+		p.Tau = paramUpdate.Tau
+	}
+	if paramUpdate.Decentralization != nil {
+		p.Decentralization = paramUpdate.Decentralization
+	}
+	if paramUpdate.ProtocolVersion != nil {
+		p.ProtocolMajor = paramUpdate.ProtocolVersion.Major
+		p.ProtocolMinor = paramUpdate.ProtocolVersion.Minor
+	}
+	if paramUpdate.Nonce != nil {
+		p.Nonce = paramUpdate.Nonce
+	}
+	if paramUpdate.MinUtxoValue != nil {
+		p.MinUtxoValue = *paramUpdate.MinUtxoValue
+	}
+}
+
+func (p *ShelleyProtocolParameters) UpdateFromGenesis(genesis *ShelleyGenesis) {
+	genesisParams := genesis.ProtocolParameters
+	p.MinFeeA = genesisParams.MinFeeA
+	p.MinFeeB = genesisParams.MinFeeB
+	p.MaxBlockBodySize = genesisParams.MaxBlockBodySize
+	p.MaxTxSize = genesisParams.MaxTxSize
+	p.MaxBlockHeaderSize = genesisParams.MaxBlockHeaderSize
+	p.KeyDeposit = genesisParams.KeyDeposit
+	p.PoolDeposit = genesisParams.PoolDeposit
+	p.MaxEpoch = genesisParams.MaxEpoch
+	p.NOpt = genesisParams.NOpt
+	if genesisParams.A0 != nil {
+		p.A0 = &cbor.Rat{new(big.Rat).Set(genesisParams.A0.Rat)}
+	}
+	if genesisParams.Rho != nil {
+		p.Rho = &cbor.Rat{new(big.Rat).Set(genesisParams.Rho.Rat)}
+	}
+	if genesisParams.Tau != nil {
+		p.Tau = &cbor.Rat{new(big.Rat).Set(genesisParams.Tau.Rat)}
+	}
+	if genesisParams.Decentralization != nil {
+		p.Decentralization = &cbor.Rat{new(big.Rat).Set(genesisParams.Decentralization.Rat)}
+	}
+	p.ProtocolMajor = genesisParams.ProtocolVersion.Major
+	p.ProtocolMinor = genesisParams.ProtocolVersion.Minor
+	p.MinUtxoValue = genesisParams.MinUtxoValue
+	// TODO:
+	//p.Nonce              *cbor.Rat
+}
+
+type ShelleyProtocolParametersProtocolVersion struct {
+	cbor.StructAsArray
+	Major uint
+	Minor uint
+}
+
+type ShelleyProtocolParameterUpdate struct {
+	cbor.DecodeStoreCbor
+	MinFeeA            *uint                                     `cbor:"0,keyasint"`
+	MinFeeB            *uint                                     `cbor:"1,keyasint"`
+	MaxBlockBodySize   *uint                                     `cbor:"2,keyasint"`
+	MaxTxSize          *uint                                     `cbor:"3,keyasint"`
+	MaxBlockHeaderSize *uint                                     `cbor:"4,keyasint"`
+	KeyDeposit         *uint                                     `cbor:"5,keyasint"`
+	PoolDeposit        *uint                                     `cbor:"6,keyasint"`
+	MaxEpoch           *uint                                     `cbor:"7,keyasint"`
+	NOpt               *uint                                     `cbor:"8,keyasint"`
+	A0                 *cbor.Rat                                 `cbor:"9,keyasint"`
+	Rho                *cbor.Rat                                 `cbor:"10,keyasint"`
+	Tau                *cbor.Rat                                 `cbor:"11,keyasint"`
+	Decentralization   *cbor.Rat                                 `cbor:"12,keyasint"`
+	Nonce              *Nonce                                    `cbor:"13,keyasint"`
+	ProtocolVersion    *ShelleyProtocolParametersProtocolVersion `cbor:"14,keyasint"`
+	MinUtxoValue       *uint                                     `cbor:"15,keyasint"`
+}
+
+func (ShelleyProtocolParameterUpdate) IsProtocolParameterUpdate() {}
+
+func (u *ShelleyProtocolParameterUpdate) UnmarshalCBOR(data []byte) error {
+	return u.UnmarshalCbor(data, u)
+}
+
+const (
+	NonceType0 = 0
+	NonceType1 = 1
+)
+
+var NeutralNonce = Nonce{
+	Type: NonceType0,
+}
+
+type Nonce struct {
+	cbor.StructAsArray
+	Type  uint
+	Value [32]byte
+}
+
+func (n *Nonce) UnmarshalCBOR(data []byte) error {
+	nonceType, err := cbor.DecodeIdFromList(data)
+	if err != nil {
+		return err
+	}
+
+	n.Type = uint(nonceType)
+
+	switch nonceType {
+	case NonceType0:
+		// Value uses default value
+	case NonceType1:
+		if err := cbor.DecodeGeneric(data, n); err != nil {
+			fmt.Printf("Nonce decode error: %+v\n", data)
+			return err
+		}
+	default:
+		return fmt.Errorf("unsupported nonce type %d", nonceType)
+	}
+	return nil
+}

ledger/shelley/pparams_test.go

@@ -0,0 +1,131 @@
+// Copyright 2024 Blink Labs Software
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shelley_test
+
+import (
+	"encoding/hex"
+	"math/big"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/blinklabs-io/gouroboros/cbor"
+	"github.com/blinklabs-io/gouroboros/ledger/shelley"
+)
+
+func TestNonceUnmarshalCBOR(t *testing.T) {
+	testCases := []struct {
+		name        string
+		data        []byte
+		expectedErr string
+	}{
+		{
+			name: "NonceType0",
+			data: []byte{0x81, 0x00},
+		},
+		{
+			name: "NonceType1",
+			data: []byte{0x82, 0x01, 0x42, 0x01, 0x02},
+		},
+		{
+			name:        "UnsupportedNonceType",
+			data:        []byte{0x82, 0x02},
+			expectedErr: "unsupported nonce type 2",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			n := &shelley.Nonce{}
+			err := n.UnmarshalCBOR(tc.data)
+			if err != nil {
+				if tc.expectedErr == "" || err.Error() != tc.expectedErr {
+					t.Errorf("unexpected error: %v", err)
+				}
+			} else if tc.expectedErr != "" {
+				t.Errorf("expected error: %v, got nil", tc.expectedErr)
+			}
+		})
+	}
+}
+
+func TestShelleyProtocolParamsUpdate(t *testing.T) {
+	testDefs := []struct {
+		startParams    shelley.ShelleyProtocolParameters
+		updateCbor     string
+		expectedParams shelley.ShelleyProtocolParameters
+	}{
+		{
+			startParams: shelley.ShelleyProtocolParameters{
+				Decentralization: &cbor.Rat{new(big.Rat).SetInt64(1)},
+			},
+			updateCbor: "a10cd81e82090a",
+			expectedParams: shelley.ShelleyProtocolParameters{
+				Decentralization: &cbor.Rat{big.NewRat(9, 10)},
+			},
+		},
+		{
+			startParams: shelley.ShelleyProtocolParameters{
+				ProtocolMajor: 2,
+			},
+			updateCbor: "a10e820300",
+			expectedParams: shelley.ShelleyProtocolParameters{
+				ProtocolMajor: 3,
+			},
+		},
+	}
+	for _, testDef := range testDefs {
+		cborBytes, err := hex.DecodeString(testDef.updateCbor)
+		if err != nil {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		var tmpUpdate shelley.ShelleyProtocolParameterUpdate
+		if _, err := cbor.Decode(cborBytes, &tmpUpdate); err != nil {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		tmpParams := testDef.startParams
+		tmpParams.Update(&tmpUpdate)
+		if !reflect.DeepEqual(tmpParams, testDef.expectedParams) {
+			t.Fatalf("did not get expected params:\n     got: %#v\n  wanted: %#v", tmpParams, testDef.expectedParams)
+		}
+	}
+}
+
+func TestShelleyProtocolParamsUpdateFromGenesis(t *testing.T) {
+	testDefs := []struct {
+		startParams    shelley.ShelleyProtocolParameters
+		genesisJson    string
+		expectedParams shelley.ShelleyProtocolParameters
+	}{
+		{
+			startParams: shelley.ShelleyProtocolParameters{},
+			genesisJson: `{"protocolParams":{"decentralisationParam":0.9}}`,
+			expectedParams: shelley.ShelleyProtocolParameters{
+				Decentralization: &cbor.Rat{big.NewRat(9, 10)},
+			},
+		},
+	}
+	for _, testDef := range testDefs {
+		tmpGenesis, err := shelley.NewShelleyGenesisFromReader(strings.NewReader(testDef.genesisJson))
+		if err != nil {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		tmpParams := testDef.startParams
+		tmpParams.UpdateFromGenesis(&tmpGenesis)
+		if !reflect.DeepEqual(tmpParams, testDef.expectedParams) {
+			t.Fatalf("did not get expected params:\n     got: %#v\n  wanted: %#v", tmpParams, testDef.expectedParams)
+		}
+	}
+}