core/types: remove LogForStorage type (ethereum#23173)

The encoding of Log and LogForStorage is exactly the same
now. After tracking it down it seems like ethereum#17106 changed the
storage schema of logs to be the same as the consensus
encoding.

Support for the legacy format was dropped in ethereum#22852 and if
I'm not wrong there's no reason anymore to have these two
equivalent types.

Since the RLP encoding simply contains the first three fields
of Log, we can also avoid creating a temporary struct for
encoding/decoding, and use the rlp:"-" tag in Log instead.

Note: this is an API change in core/types. We decided it's OK
to make this change because LogForStorage is an implementation
detail of go-ethereum and the type has zero uses outside of
package core/types.

Co-authored-by: Felix Lange <fjl@twurst.com>

core/types/log.go

@@ -17,11 +17,8 @@
 package types
 
 import (
-	"io"
-
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/ethereum/go-ethereum/rlp"
 )
 
 //go:generate gencodec -type Log -field-override logMarshaling -out gen_log_json.go
@@ -40,19 +37,19 @@ type Log struct {
 	// Derived fields. These fields are filled in by the node
 	// but not secured by consensus.
 	// block in which the transaction was included
-	BlockNumber uint64 `json:"blockNumber"`
+	BlockNumber uint64 `json:"blockNumber" rlp:"-"`
 	// hash of the transaction
-	TxHash common.Hash `json:"transactionHash" gencodec:"required"`
+	TxHash common.Hash `json:"transactionHash" gencodec:"required" rlp:"-"`
 	// index of the transaction in the block
-	TxIndex uint `json:"transactionIndex"`
+	TxIndex uint `json:"transactionIndex" rlp:"-"`
 	// hash of the block in which the transaction was included
-	BlockHash common.Hash `json:"blockHash"`
+	BlockHash common.Hash `json:"blockHash" rlp:"-"`
 	// index of the log in the block
-	Index uint `json:"logIndex"`
+	Index uint `json:"logIndex" rlp:"-"`
 
 	// The Removed field is true if this log was reverted due to a chain reorganisation.
 	// You must pay attention to this field if you receive logs through a filter query.
-	Removed bool `json:"removed"`
+	Removed bool `json:"removed" rlp:"-"`
 }
 
 type logMarshaling struct {
@@ -61,52 +58,3 @@ type logMarshaling struct {
 	TxIndex     hexutil.Uint
 	Index       hexutil.Uint
 }
-
-type rlpLog struct {
-	Address common.Address
-	Topics  []common.Hash
-	Data    []byte
-}
-
-// rlpStorageLog is the storage encoding of a log.
-type rlpStorageLog rlpLog
-
-// EncodeRLP implements rlp.Encoder.
-func (l *Log) EncodeRLP(w io.Writer) error {
-	return rlp.Encode(w, rlpLog{Address: l.Address, Topics: l.Topics, Data: l.Data})
-}
-
-// DecodeRLP implements rlp.Decoder.
-func (l *Log) DecodeRLP(s *rlp.Stream) error {
-	var dec rlpLog
-	err := s.Decode(&dec)
-	if err == nil {
-		l.Address, l.Topics, l.Data = dec.Address, dec.Topics, dec.Data
-	}
-	return err
-}
-
-// LogForStorage is a wrapper around a Log that flattens and parses the entire content of
-// a log including non-consensus fields.
-type LogForStorage Log
-
-// EncodeRLP implements rlp.Encoder.
-func (l *LogForStorage) EncodeRLP(w io.Writer) error {
-	return rlp.Encode(w, rlpStorageLog{
-		Address: l.Address,
-		Topics:  l.Topics,
-		Data:    l.Data,
-	})
-}
-
-// DecodeRLP implements rlp.Decoder.
-//
-// Note some redundant fields(e.g. block number, tx hash etc) will be assembled later.
-func (l *LogForStorage) DecodeRLP(s *rlp.Stream) error {
-	var dec rlpStorageLog
-	if err := s.Decode(&dec); err != nil {
-		return err
-	}
-	*l = LogForStorage{Address: dec.Address, Topics: dec.Topics, Data: dec.Data}
-	return nil
-}

core/types/receipt.go

@@ -94,7 +94,7 @@ type receiptRLP struct {
 type storedReceiptRLP struct {
 	PostStateOrStatus []byte
 	CumulativeGasUsed uint64
-	Logs              []*LogForStorage
+	Logs              []*Log
 }
 
 // NewReceipt creates a barebone transaction receipt, copying the init fields.
@@ -217,10 +217,7 @@ func (r *ReceiptForStorage) EncodeRLP(w io.Writer) error {
 	enc := &storedReceiptRLP{
 		PostStateOrStatus: (*Receipt)(r).statusEncoding(),
 		CumulativeGasUsed: r.CumulativeGasUsed,
-		Logs:              make([]*LogForStorage, len(r.Logs)),
-	}
-	for i, log := range r.Logs {
-		enc.Logs[i] = (*LogForStorage)(log)
+		Logs:              r.Logs,
 	}
 	return rlp.Encode(w, enc)
 }
@@ -235,10 +232,7 @@ func (r *ReceiptForStorage) DecodeRLP(s *rlp.Stream) error {
 		return err
 	}
 	r.CumulativeGasUsed = stored.CumulativeGasUsed
-	r.Logs = make([]*Log, len(stored.Logs))
-	for i, log := range stored.Logs {
-		r.Logs[i] = (*Log)(log)
-	}
+	r.Logs = stored.Logs
 	r.Bloom = CreateBloom(Receipts{(*Receipt)(r)})
 	return nil
 }