feat(core/types): Body hooks for RLP encoding

Author: qdm12

core/rawdb/accessors_chain.go

@@ -522,7 +522,8 @@ func ReadBlock(db ethdb.Reader, hash common.Hash, number uint64) *types.Block {
 	if body == nil {
 		return nil
 	}
-	return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles).WithExtData(body.Version, body.ExtData)
+	bodyExtra := types.GetBodyExtra(body)
+	return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles).WithExtData(bodyExtra.Version, bodyExtra.ExtData)
 }
 
 // WriteBlock serializes a block into the database, header and body separately.

core/types/block.go

@@ -37,15 +37,6 @@ import (
 	"github.com/ava-labs/libevm/rlp"
 )
 
-// Body is a simple (mutable, non-safe) data container for storing and moving
-// a block's data contents (transactions and uncles) together.
-type Body struct {
-	Transactions []*Transaction
-	Uncles       []*Header
-	Version      uint32
-	ExtData      *[]byte `rlp:"nil"`
-}
-
 // Block represents an Ethereum block.
 //
 // Note the Block type tries to be 'immutable', and contains certain caches that rely
@@ -152,7 +143,15 @@ func (b *Block) EncodeRLP(w io.Writer) error {
 // Body returns the non-header content of the block.
 // Note the returned data is not an independent copy.
 func (b *Block) Body() *Body {
-	return &Body{b.transactions, b.uncles, b.version, b.extdata}
+	body := &Body{
+		Transactions: b.transactions,
+		Uncles:       b.uncles,
+	}
+	extra := &BodyExtra{
+		Version: b.version,
+		ExtData: b.extdata,
+	}
+	return WithBodyExtra(body, extra)
 }
 
 // Accessors for body data. These do not return a copy because the content

core/types/body_ext.go

@@ -0,0 +1,51 @@
+// (c) 2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package types
+
+import (
+	"github.com/ava-labs/libevm/rlp"
+)
+
+func GetBodyExtra(b *Body) *BodyExtra {
+	return extras.Body.Get(b)
+}
+
+func WithBodyExtra(b *Body, extra *BodyExtra) *Body {
+	extras.Body.Set(b, extra)
+	return b
+}
+
+// BodyExtra is a struct that contains extra fields used by Avalanche
+// in the body.
+// This type uses BodySerializable to encode and decode the extra fields
+// along with the upstream type for compatibility with existing network blocks.
+type BodyExtra struct {
+	Version uint32
+	ExtData *[]byte
+
+	// Fields removed from geth:
+	//  - withdrawals  Withdrawals
+}
+
+func (b *BodyExtra) RLPFieldsForEncoding(body *Body) *rlp.Fields {
+	return &rlp.Fields{
+		Required: []any{
+			body.Transactions,
+			body.Uncles,
+			b.Version,
+			b.ExtData,
+		},
+	}
+}
+
+func (b *BodyExtra) RLPFieldPointersForDecoding(body *Body) *rlp.Fields {
+	return &rlp.Fields{
+		Required: []any{
+			&body.Transactions,
+			&body.Uncles,
+			&b.Version,
+			rlp.Nillable(&b.ExtData), // equivalent to `rlp:"nil"`
+		},
+	}
+}

core/types/imports.go

@@ -17,6 +17,7 @@ type (
 	BlobTxSidecar     = ethtypes.BlobTxSidecar
 	BlockNonce        = ethtypes.BlockNonce
 	Bloom             = ethtypes.Bloom
+	Body              = ethtypes.Body
 	DynamicFeeTx      = ethtypes.DynamicFeeTx
 	Header            = ethtypes.Header
 	HomesteadSigner   = ethtypes.HomesteadSigner

core/types/libevm.go

@@ -9,6 +9,6 @@ import (
 
 var extras = ethtypes.RegisterExtras[
 	HeaderExtra, *HeaderExtra,
-	ethtypes.NOOPBodyHooks, *ethtypes.NOOPBodyHooks,
+	BodyExtra, *BodyExtra,
 	isMultiCoin,
 ]()