Remove Block RLP hooks

core/types/backwards_compat.libevm_test.go

@@ -240,14 +240,6 @@ func (e *cChainBodyExtras) Copy() *cChainBodyExtras {
 	panic("unimplemented")
 }
 
-func (e *cChainBodyExtras) BlockRLPFieldsForEncoding(b *BlockRLPProxy) *rlp.Fields {
-	panic("unimplemented")
-}
-
-func (e *cChainBodyExtras) BlockRLPFieldPointersForDecoding(b *BlockRLPProxy) *rlp.Fields {
-	panic("unimplemented")
-}
-
 func TestBodyRLPCChainCompat(t *testing.T) {
 	// The inputs to this test were used to generate the expected RLP with
 	// ava-labs/coreth. This serves as both an example of how to use [BodyHooks]

core/types/block.go

@@ -222,7 +222,7 @@ type extblock struct {
 	Uncles      []*Header
 	Withdrawals []*Withdrawal `rlp:"optional"`
 
-	hooks BlockBodyHooks // libevm: MUST be unexported + populated from [Block.hooks]
+	extra *pseudo.Type // libevm: MUST be unexported + populated from [Block.extraOrNil]
 }
 
 // NewBlock creates a new block. The input data is copied, changes to header and to the
@@ -322,7 +322,7 @@ func CopyHeader(h *Header) *Header {
 // DecodeRLP decodes a block from RLP.
 func (b *Block) DecodeRLP(s *rlp.Stream) error {
 	var eb extblock
-	eb.hooks = b.hooks()
+	eb.extra = b.extraOrNil()
 	_, size, _ := s.Kind()
 	if err := s.Decode(&eb); err != nil {
 		return err
@@ -339,7 +339,7 @@ func (b *Block) EncodeRLP(w io.Writer) error {
 		Txs:         b.transactions,
 		Uncles:      b.uncles,
 		Withdrawals: b.withdrawals,
-		hooks:       b.hooks(),
+		extra:       b.extraOrNil(),
 	})
 }
 

core/types/block.libevm.go

@@ -18,6 +18,7 @@ package types
 
 import (
 	"encoding/json"
+	"fmt"
 	"io"
 
 	"github.com/ava-labs/libevm/internal/libevm/pseudo"
@@ -106,25 +107,80 @@ func (b *Body) DecodeRLP(s *rlp.Stream) error {
 	return b.hooks().BodyRLPFieldPointersForDecoding(b).DecodeRLP(s)
 }
 
-// BlockRLPProxy exports the geth-internal type used for RLP {en,de}coding of a
-// [Block].
-type BlockRLPProxy extblock
-
 func (b *extblock) EncodeRLP(w io.Writer) error {
-	bb := (*BlockRLPProxy)(b)
-	return b.hooks.BlockRLPFieldsForEncoding(bb).EncodeRLP(w)
+	body := Body{
+		Transactions: b.Txs,
+		Uncles:       b.Uncles,
+		Withdrawals:  b.Withdrawals,
+		extra:        b.extra,
+	}
+	bodyFields := body.hooks().BodyRLPFieldsForEncoding(&body)
+	blockFields := rlp.Fields{
+		Required: append(
+			[]any{b.Header},
+			bodyFields.Required...,
+		),
+		Optional: bodyFields.Optional,
+	}
+	return blockFields.EncodeRLP(w)
 }
 
 func (b *extblock) DecodeRLP(s *rlp.Stream) error {
-	bb := (*BlockRLPProxy)(b)
-	return b.hooks.BlockRLPFieldPointersForDecoding(bb).DecodeRLP(s)
+	body := Body{
+		// The body provided to the hooks is expected to contain the same extra
+		// as the method receiver.
+		extra: b.extra,
+	}
+	bodyFields := body.hooks().BodyRLPFieldPointersForDecoding(&body)
+	blockFields := rlp.Fields{
+		Required: append(
+			[]any{&b.Header},
+			bodyFields.Required...,
+		),
+		Optional: bodyFields.Optional,
+	}
+	if err := blockFields.DecodeRLP(s); err != nil {
+		return err
+	}
+	b.Txs = body.Transactions
+	b.Uncles = body.Uncles
+	b.Withdrawals = body.Withdrawals
+	return nil
+}
+
+// BlockBytes combines an RLP encoded [Header] and [Body] into an RLP encoded
+// [Block].
+//
+// For correctly formatted inputs it is a faster equivalent of:
+//   - Decoding into a [Header] and [Body]
+//   - Combining them into a Block
+//   - Encoding the Block
+//
+// This function does NOT validate the header or body.
+func BlockBytes(headerBytes, bodyBytes []byte) ([]byte, error) {
+	bodyFields, _, err := rlp.SplitList(bodyBytes)
+	if err != nil {
+		return nil, fmt.Errorf("splitting body: %w", err)
+	}
+
+	w := rlp.NewEncoderBuffer(nil)
+	l := w.List()
+	if _, err := w.Write(headerBytes); err != nil {
+		return nil, fmt.Errorf("writing header: %w", err)
+	}
+	if _, err := w.Write(bodyFields); err != nil {
+		return nil, fmt.Errorf("writing body: %w", err)
+	}
+	w.ListEnd(l)
+	blockBytes := w.ToBytes()
+	return blockBytes, w.Flush() // Flush returns the internal buffer to the pool.
 }
 
 // BlockBodyHooks are required for all types registered with [RegisterExtras]
-// for [Block] and [Body] payloads.
+// for [Block] and [Body] payloads. The same methods are used for both [Block]
+// and [Body] {en,de}coding as a Block is encoded as its [Header] followed by
+// the fields of its [Body].
 type BlockBodyHooks interface {
-	BlockRLPFieldsForEncoding(*BlockRLPProxy) *rlp.Fields
-	BlockRLPFieldPointersForDecoding(*BlockRLPProxy) *rlp.Fields
 	BodyRLPFieldsForEncoding(*Body) *rlp.Fields
 	BodyRLPFieldPointersForDecoding(*Body) *rlp.Fields
 	PostRPCMarshal(b *Block, marshalled map[string]any)
@@ -149,27 +205,10 @@ var (
 	}
 	_ = extblock{
 		&Header{}, []*Transaction{}, []*Header{}, []*Withdrawal{}, // geth
-		BlockBodyHooks(nil), // libevm
+		&pseudo.Type{}, // libevm
 	}
-	// Demonstrate identity of these two types, by definition but useful for
-	// inspection here.
-	_ = extblock(BlockRLPProxy{})
 )
 
-func (NOOPBlockBodyHooks) BlockRLPFieldsForEncoding(b *BlockRLPProxy) *rlp.Fields {
-	return &rlp.Fields{
-		Required: []any{b.Header, b.Txs, b.Uncles},
-		Optional: []any{b.Withdrawals},
-	}
-}
-
-func (NOOPBlockBodyHooks) BlockRLPFieldPointersForDecoding(b *BlockRLPProxy) *rlp.Fields {
-	return &rlp.Fields{
-		Required: []any{&b.Header, &b.Txs, &b.Uncles},
-		Optional: []any{&b.Withdrawals},
-	}
-}
-
 func (NOOPBlockBodyHooks) BodyRLPFieldsForEncoding(b *Body) *rlp.Fields {
 	return &rlp.Fields{
 		Required: []any{b.Transactions, b.Uncles},

core/types/block.libevm_test.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"io"
 	"reflect"
+	"slices"
 	"strings"
 	"testing"
 
@@ -33,6 +34,7 @@ import (
 	"github.com/ava-labs/libevm/internal/libevm/pseudo"
 	"github.com/ava-labs/libevm/libevm/ethtest"
 	"github.com/ava-labs/libevm/rlp"
+	"github.com/ava-labs/libevm/trie"
 )
 
 type stubHeaderHooks struct {
@@ -272,3 +274,210 @@ func TestBlockWithX(t *testing.T) {
 		})
 	}
 }
+
+// bodyPayload is a [types.BlockBodyHooks] implementation carrying an extra
+// field that is {en,de}coded as if it was a regular RLP field of both the
+// [types.Block] and [types.Body].
+type bodyPayload struct {
+	Data []byte
+
+	NOOPBlockBodyHooks
+}
+
+func (p *bodyPayload) Copy() *bodyPayload {
+	return &bodyPayload{
+		Data: slices.Clone(p.Data),
+	}
+}
+
+var rlpBodyPayloads pseudo.Accessor[*Body, *bodyPayload]
+
+func (*bodyPayload) BodyRLPFieldsForEncoding(b *Body) *rlp.Fields {
+	// Rather than using the receiver directly, we access it through b. This
+	// demonstrates that the hooks can access their own payload via the
+	// [types.Body] they are passed.
+	p := rlpBodyPayloads.Get(b)
+	return &rlp.Fields{
+		Required: []any{b.Transactions, b.Uncles, p.Data},
+		Optional: []any{b.Withdrawals},
+	}
+}
+
+func (*bodyPayload) BodyRLPFieldPointersForDecoding(b *Body) *rlp.Fields {
+	// See above comment on why we access the receiver through b rather than
+	// directly.
+	p := rlpBodyPayloads.Get(b)
+	return &rlp.Fields{
+		Required: []any{&b.Transactions, &b.Uncles, &p.Data},
+		Optional: []any{&b.Withdrawals},
+	}
+}
+
+// TestBodyExtraRoundTrip demonstrates that the extra from the method receiver
+// is the same as the extra from the argument for [types.BlockBodyHooks]
+// functions.
+func TestBodyExtraRoundTrip(t *testing.T) {
+	TestOnlyClearRegisteredExtras()
+	t.Cleanup(TestOnlyClearRegisteredExtras)
+
+	extras := RegisterExtras[
+		NOOPHeaderHooks, *NOOPHeaderHooks,
+		bodyPayload, *bodyPayload,
+		struct{},
+	]()
+	rlpBodyPayloads = extras.Body
+
+	rng := ethtest.NewPseudoRand(142857)
+	wantBlock := NewBlock(
+		&Header{ParentHash: rng.Hash()},
+		[]*Transaction{
+			NewTx(&LegacyTx{Nonce: rng.Uint64()}),
+		},
+		[]*Header{
+			{ParentHash: rng.Hash()},
+		},
+		nil,
+		trie.NewStackTrie(nil),
+	)
+	want := extras.Block.Get(wantBlock)
+	want.Data = rng.Bytes(8)
+
+	b, err := rlp.EncodeToBytes(wantBlock)
+	require.NoErrorf(t, err, "rlp.EncodeToBytes(%T)", wantBlock)
+
+	gotBlock := new(Block)
+	require.NoErrorf(t, rlp.DecodeBytes(b, gotBlock), "rlp.DecodeBytes(rlp.EncodeToBytes(%T), %T)", wantBlock, gotBlock)
+	got := extras.Block.Get(gotBlock)
+	assert.Equalf(t, want, got, "%T payload after RLP round trip", got)
+}
+
+// newHeader returns a [Header] with randomly populated fields.
+func newHeader(rng *ethtest.PseudoRand) *Header {
+	return &Header{
+		ParentHash:  rng.Hash(),
+		UncleHash:   rng.Hash(),
+		Coinbase:    rng.Address(),
+		Root:        rng.Hash(),
+		TxHash:      rng.Hash(),
+		ReceiptHash: rng.Hash(),
+		Bloom:       rng.Bloom(),
+		Difficulty:  rng.BigUint64(),
+		Number:      rng.BigUint64(),
+		GasLimit:    rng.Uint64(),
+		GasUsed:     rng.Uint64(),
+		Time:        rng.Uint64(),
+		Extra:       rng.Bytes(32),
+		MixDigest:   rng.Hash(),
+		Nonce:       rng.BlockNonce(),
+		BaseFee:     rng.BigUint64(),
+	}
+}
+
+// bodySize describes the number of items in the [Body] of a test case.
+type bodySize struct {
+	txs, uncles, withdrawals int
+}
+
+// bodySizes are the [Body] shapes covered by [FuzzBlockBytes] seeds and by
+// [BenchmarkBlockBytes]. They cover every combination of empty and non-empty
+// fields, the last of which is optional in RLP.
+var bodySizes = []bodySize{
+	{txs: 0, uncles: 0, withdrawals: 0},
+	{txs: 1, uncles: 0, withdrawals: 0},
+	{txs: 0, uncles: 1, withdrawals: 0},
+	{txs: 0, uncles: 0, withdrawals: 1},
+	{txs: 10, uncles: 0, withdrawals: 0},
+	{txs: 10, uncles: 2, withdrawals: 4},
+	{txs: 100, uncles: 0, withdrawals: 0},
+	{txs: 100, uncles: 2, withdrawals: 16},
+}
+
+// newBody returns a [Body] with randomly populated fields, holding the number
+// of items described by `size`.
+func newBody(rng *ethtest.PseudoRand, size bodySize) *Body {
+	body := &Body{}
+	for range size.txs {
+		body.Transactions = append(body.Transactions, NewTx(&LegacyTx{
+			Nonce:    rng.Uint64(),
+			GasPrice: rng.BigUint64(),
+			Gas:      rng.Uint64(),
+			To:       rng.AddressPtr(),
+			Value:    rng.BigUint64(),
+			Data:     rng.Bytes(64),
+		}))
+	}
+	for range size.uncles {
+		body.Uncles = append(body.Uncles, newHeader(rng))
+	}
+	for range size.withdrawals {
+		body.Withdrawals = append(body.Withdrawals, &Withdrawal{
+			Index:     rng.Uint64(),
+			Validator: rng.Uint64(),
+			Address:   rng.Address(),
+			Amount:    rng.Uint64(),
+		})
+	}
+	return body
+}
+
+// encodeRLP RLP-encodes `v`, failing the test if it can't be encoded.
+func encodeRLP(tb testing.TB, v any) []byte {
+	tb.Helper()
+	b, err := rlp.EncodeToBytes(v)
+	require.NoErrorf(tb, err, "rlp.EncodeToBytes(%T)", v)
+	return b
+}
+
+// referenceBlockBytes is the reference implementation against which
+// [BlockBytes] is tested and benchmarked.
+func referenceBlockBytes(headerBytes, bodyBytes []byte) ([]byte, error) {
+	header := new(Header)
+	if err := rlp.DecodeBytes(headerBytes, header); err != nil {
+		return nil, err
+	}
+	body := new(Body)
+	if err := rlp.DecodeBytes(bodyBytes, body); err != nil {
+		return nil, err
+	}
+	block := NewBlockWithHeader(header).
+		WithBody(*body).
+		WithWithdrawals(body.Withdrawals)
+	return rlp.EncodeToBytes(block)
+}
+
+// FuzzBlockBytes demonstrates that [BlockBytes] is equivalent to
+// [referenceBlockBytes] for all inputs that the latter accepts. The seed corpus
+// covers every shape in [bodySizes].
+func FuzzBlockBytes(f *testing.F) {
+	rng := ethtest.NewPseudoRand(20250806)
+	for _, size := range bodySizes {
+		f.Add(
+			encodeRLP(f, newHeader(rng)),
+			encodeRLP(f, newBody(rng, size)),
+		)
+	}
+
+	f.Fuzz(func(t *testing.T, headerBytes, bodyBytes []byte) {
+		want, err := referenceBlockBytes(headerBytes, bodyBytes)
+		if err != nil {
+			t.Skip("invalid input bytes")
+		}
+
+		got, err := BlockBytes(headerBytes, bodyBytes)
+		require.NoError(t, err, "BlockBytes()")
+		assert.Equal(t, want, got, "referenceBlockBytes() == BlockBytes()")
+	})
+}
+
+func BenchmarkBlockBytes(b *testing.B) {
+	for _, size := range bodySizes {
+		rng := ethtest.NewPseudoRand(2718281828)
+		headerBytes := encodeRLP(b, newHeader(rng))
+		bodyBytes := encodeRLP(b, newBody(rng, size))
+		b.Run(fmt.Sprintf("%d_txs_%d_uncles_%d_withdrawals", size.txs, size.uncles, size.withdrawals), func(b *testing.B) {
+			for b.Loop() {
+				_, _ = BlockBytes(headerBytes, bodyBytes)
+			}
+		})
+	}
+}