beacon/types: add ExecutionHeader

beacon/types/exec_header.go

@@ -0,0 +1,80 @@
+// Copyright 2024 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package types
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/beacon/merkle"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/protolambda/zrnt/eth2/beacon/capella"
+	zrntcommon "github.com/protolambda/zrnt/eth2/beacon/common"
+	"github.com/protolambda/zrnt/eth2/beacon/deneb"
+	"github.com/protolambda/ztyp/tree"
+)
+
+type headerObject interface {
+	HashTreeRoot(hFn tree.HashFn) zrntcommon.Root
+}
+
+type ExecutionHeader struct {
+	obj headerObject
+}
+
+// HeaderFromJSON decodes an execution header from JSON data provided by
+// the beacon chain API.
+func ExecutionHeaderFromJSON(forkName string, data []byte) (*ExecutionHeader, error) {
+	var obj headerObject
+	switch forkName {
+	case "capella":
+		obj = new(capella.ExecutionPayloadHeader)
+	case "deneb":
+		obj = new(deneb.ExecutionPayloadHeader)
+	default:
+		return nil, fmt.Errorf("unsupported fork: " + forkName)
+	}
+	if err := json.Unmarshal(data, obj); err != nil {
+		return nil, err
+	}
+	return &ExecutionHeader{obj: obj}, nil
+}
+
+func NewExecutionHeader(obj headerObject) *ExecutionHeader {
+	switch obj.(type) {
+	case *capella.ExecutionPayloadHeader:
+	case *deneb.ExecutionPayloadHeader:
+	default:
+		panic(fmt.Errorf("unsupported ExecutionPayloadHeader type %T", obj))
+	}
+	return &ExecutionHeader{obj: obj}
+}
+
+func (eh *ExecutionHeader) PayloadRoot() merkle.Value {
+	return merkle.Value(eh.obj.HashTreeRoot(tree.GetHashFn()))
+}
+
+func (eh *ExecutionHeader) BlockHash() common.Hash {
+	switch obj := eh.obj.(type) {
+	case *capella.ExecutionPayloadHeader:
+		return common.Hash(obj.BlockHash)
+	case *deneb.ExecutionPayloadHeader:
+		return common.Hash(obj.BlockHash)
+	default:
+		panic(fmt.Errorf("unsupported ExecutionPayloadHeader type %T", obj))
+	}
+}

beacon/types/light_sync.go

@@ -24,8 +24,6 @@ import (
 	"github.com/ethereum/go-ethereum/beacon/merkle"
 	"github.com/ethereum/go-ethereum/beacon/params"
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/protolambda/zrnt/eth2/beacon/capella"
-	"github.com/protolambda/ztyp/tree"
 )
 
 // HeadInfo represents an unvalidated new head announcement.
@@ -146,12 +144,12 @@ func (u UpdateScore) BetterThan(w UpdateScore) bool {
 
 type HeaderWithExecProof struct {
 	Header
-	PayloadHeader *capella.ExecutionPayloadHeader
+	PayloadHeader *ExecutionHeader
 	PayloadBranch merkle.Values
 }
 
 func (h *HeaderWithExecProof) Validate() error {
-	payloadRoot := merkle.Value(h.PayloadHeader.HashTreeRoot(tree.GetHashFn()))
+	payloadRoot := h.PayloadHeader.PayloadRoot()
 	return merkle.VerifyProof(h.BodyRoot, params.BodyIndexExecPayload, h.PayloadBranch, payloadRoot)
 }