fix(bmr): send only one receipt per transaction

cmd/iconbridge/chain/bsc/sender.go

@@ -29,6 +29,8 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain"
+	"github.com/icon-project/icon-bridge/cmd/iconbridge/common/chainutils"
+
 	bscTypes "github.com/icon-project/icon-bridge/cmd/iconbridge/chain/bsc/types"
 	"github.com/icon-project/icon-bridge/common/codec"
 	"github.com/icon-project/icon-bridge/common/intconv"
@@ -163,41 +165,16 @@ func (s *sender) Segment(
 		return nil, msg, nil
 	}
 
-	rm := &chain.RelayMessage{
-		Receipts: make([][]byte, 0),
+	relayMsg, newMsg, err := chainutils.SegmentByTxDataSize(msg, s.opts.TxDataSizeLimit)
+	if err != nil {
+		return nil, nil, err
 	}
 
-	var msgSize uint64
-
-	newMsg = &chain.Message{
-		From:     msg.From,
-		Receipts: msg.Receipts,
-	}
-	for i, receipt := range msg.Receipts {
-		rlpEvents, err := codec.RLP.MarshalToBytes(receipt.Events)
-		if err != nil {
-			return nil, nil, err
-		}
-		rlpReceipt, err := codec.RLP.MarshalToBytes(&chain.RelayReceipt{
-			Index:  receipt.Index,
-			Height: receipt.Height,
-			Events: rlpEvents,
-		})
-		if err != nil {
-			return nil, nil, err
-		}
-		newMsgSize := msgSize + uint64(len(rlpReceipt))
-		if newMsgSize > s.opts.TxDataSizeLimit {
-			newMsg.Receipts = msg.Receipts[i:]
-			break
-		}
-		msgSize = newMsgSize
-		rm.Receipts = append(rm.Receipts, rlpReceipt)
-	}
-	message, err := codec.RLP.MarshalToBytes(rm)
+	message, err := codec.RLP.MarshalToBytes(relayMsg)
 	if err != nil {
 		return nil, nil, err
 	}
+
 	cl, _ := s.jointClient()
 	gasPrice, gasHeight, err := cl.GetMedianGasPriceForBlock(ctx)
 	if err != nil || gasPrice.Int64() == 0 {

cmd/iconbridge/chain/hmny/sender.go

@@ -16,6 +16,7 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain"
+	"github.com/icon-project/icon-bridge/cmd/iconbridge/common/chainutils"
 	"github.com/icon-project/icon-bridge/common/codec"
 	"github.com/icon-project/icon-bridge/common/intconv"
 	"github.com/icon-project/icon-bridge/common/log"
@@ -135,40 +136,12 @@ func (s *sender) Segment(
 		return nil, msg, nil
 	}
 
-	rm := &chain.RelayMessage{
-		Receipts: make([][]byte, 0),
-	}
-
-	var msgSize uint64
-
-	newMsg = &chain.Message{
-		From:     msg.From,
-		Receipts: msg.Receipts,
-	}
-
-	for i, receipt := range msg.Receipts {
-		rlpEvents, err := codec.RLP.MarshalToBytes(receipt.Events)
-		if err != nil {
-			return nil, nil, err
-		}
-		rlpReceipt, err := codec.RLP.MarshalToBytes(&chain.RelayReceipt{
-			Index:  receipt.Index,
-			Height: receipt.Height,
-			Events: rlpEvents,
-		})
-		if err != nil {
-			return nil, nil, err
-		}
-		newMsgSize := msgSize + uint64(len(rlpReceipt))
-		if newMsgSize > s.opts.TxDataSizeLimit {
-			newMsg.Receipts = msg.Receipts[i:]
-			break
-		}
-		msgSize = newMsgSize
-		rm.Receipts = append(rm.Receipts, rlpReceipt)
+	relayMsg, newMsg, err := chainutils.SegmentByTxDataSize(msg, s.opts.TxDataSizeLimit)
+	if err != nil {
+		return nil, nil, err
 	}
 
-	message, err := codec.RLP.MarshalToBytes(rm)
+	message, err := codec.RLP.MarshalToBytes(relayMsg)
 	if err != nil {
 		return nil, nil, err
 	}

cmd/iconbridge/chain/icon/sender.go

@@ -21,12 +21,14 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain/icon/types"
 	"math/big"
 	"net/url"
 	"strconv"
 	"time"
 
+	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain/icon/types"
+	"github.com/icon-project/icon-bridge/cmd/iconbridge/common/chainutils"
+
 	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain"
 	"github.com/icon-project/icon-bridge/common"
 	"github.com/icon-project/icon-bridge/common/codec"
@@ -147,40 +149,12 @@ func (s *sender) Segment(
 		return nil, msg, nil
 	}
 
-	rm := &chain.RelayMessage{
-		Receipts: make([][]byte, 0),
-	}
-
-	var msgSize uint64
-
-	newMsg = &chain.Message{
-		From:     msg.From,
-		Receipts: msg.Receipts,
-	}
-
-	for i, receipt := range msg.Receipts {
-		rlpEvents, err := codec.RLP.MarshalToBytes(receipt.Events)
-		if err != nil {
-			return nil, nil, err
-		}
-		rlpReceipt, err := codec.RLP.MarshalToBytes(&chain.RelayReceipt{
-			Index:  receipt.Index,
-			Height: receipt.Height,
-			Events: rlpEvents,
-		})
-		if err != nil {
-			return nil, nil, err
-		}
-		newMsgSize := msgSize + uint64(len(rlpReceipt))
-		if newMsgSize > s.opts.TxDataSizeLimit {
-			newMsg.Receipts = msg.Receipts[i:]
-			break
-		}
-		msgSize = newMsgSize
-		rm.Receipts = append(rm.Receipts, rlpReceipt)
+	relayMsg, newMsg, err := chainutils.SegmentByTxDataSize(msg, s.opts.TxDataSizeLimit)
+	if err != nil {
+		return nil, nil, err
 	}
 
-	message, err := codec.RLP.MarshalToBytes(rm)
+	message, err := codec.RLP.MarshalToBytes(relayMsg)
 	if err != nil {
 		return nil, nil, err
 	}

cmd/iconbridge/chain/near/sender.go

@@ -12,13 +12,16 @@ import (
 	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain"
 	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain/near/errors"
 	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain/near/types"
+	"github.com/icon-project/icon-bridge/cmd/iconbridge/common/chainutils"
 	"github.com/icon-project/icon-bridge/common/codec"
 	"github.com/icon-project/icon-bridge/common/log"
 	"github.com/icon-project/icon-bridge/common/wallet"
 )
 
 const (
-	txMaxDataSize        = 64 * 1024
+	txMaxDataSize        = 4 * 1024
+	txOverheadScale      = 0.01 // base64 encoding overhead 0.36, rlp and other fields 0.01
+	defaultTxSizeLimit   = txMaxDataSize / (1 + txOverheadScale)
 	functionCallMethod   = "handle_relay_message"
 	gas                  = uint64(300000000000000)
 	defaultSendTxTimeout = 15 * time.Second
@@ -32,6 +35,7 @@ type Sender struct {
 	wallet      Wallet
 	logger      log.Logger
 	options     struct {
+		TxDataSizeLimit  uint64       `json:"tx_data_size_limit"`
 		BalanceThreshold types.BigInt `json:"balance_threshold"`
 	}
 }
@@ -75,48 +79,28 @@ func (s *Sender) client() IClient {
 	return s.clients[rand.Intn(len(s.clients))]
 }
 
-func (s *Sender) Segment(ctx context.Context, msg *chain.Message) (tx chain.RelayTx, newMsg *chain.Message, err error) {
+func (s *Sender) Segment(
+	ctx context.Context, msg *chain.Message,
+) (tx chain.RelayTx, newMsg *chain.Message, err error) {
 	if ctx.Err() != nil {
 		return nil, nil, ctx.Err()
 	}
 
-	if len(msg.Receipts) == 0 {
-		return nil, msg, nil
+	if s.options.TxDataSizeLimit == 0 {
+		limit := defaultTxSizeLimit
+		s.options.TxDataSizeLimit = uint64(limit)
 	}
 
-	rm := &chain.RelayMessage{
-		Receipts: make([][]byte, 0),
+	if len(msg.Receipts) == 0 {
+		return nil, msg, nil
 	}
 
-	var msgSize uint64
-
-	newMsg = &chain.Message{
-		From:     msg.From,
-		Receipts: msg.Receipts,
-	}
-	for i, receipt := range msg.Receipts {
-		rlpEvents, err := codec.RLP.MarshalToBytes(receipt.Events)
-		if err != nil {
-			return nil, nil, err
-		}
-		rlpReceipt, err := codec.RLP.MarshalToBytes(&chain.RelayReceipt{
-			Index:  receipt.Index,
-			Height: receipt.Height,
-			Events: rlpEvents,
-		})
-		if err != nil {
-			return nil, nil, err
-		}
-		newMsgSize := msgSize + uint64(len(rlpReceipt))
-		if newMsgSize > txMaxDataSize {
-			newMsg.Receipts = msg.Receipts[i:]
-			break
-		}
-		msgSize = newMsgSize
-		rm.Receipts = append(rm.Receipts, rlpReceipt)
+	relayMsg, newMsg, err := chainutils.SegmentByTxDataSize(msg, s.options.TxDataSizeLimit)
+	if err != nil {
+		return nil, nil, err
 	}
 
-	message, err := codec.RLP.MarshalToBytes(rm)
+	message, err := codec.RLP.MarshalToBytes(relayMsg)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -128,7 +112,6 @@ func (s *Sender) Segment(ctx context.Context, msg *chain.Message) (tx chain.Rela
 
 	return tx, newMsg, nil
 }
-
 func (s *Sender) newRelayTransaction(ctx context.Context, prev string, message []byte) (*RelayTransaction, error) {
 	if nearWallet, Ok := (s.wallet).(*wallet.NearWallet); Ok {
 		accountId := nearWallet.Address()

cmd/iconbridge/common/chainutils/segment.go

@@ -0,0 +1,67 @@
+package chainutils
+
+import (
+	"github.com/icon-project/icon-bridge/cmd/iconbridge/chain"
+	"github.com/icon-project/icon-bridge/common/codec"
+)
+
+func SegmentByTxDataSize(msg *chain.Message, txDataSizeLimit uint64) (relayMsg *chain.RelayMessage, newMsg *chain.Message, err error) {
+
+	relayMsg = &chain.RelayMessage{
+		Receipts: make([][]byte, 0),
+	}
+
+	newMsg = &chain.Message{
+		From:     msg.From,
+		Receipts: msg.Receipts,
+	}
+
+	var msgSize uint64
+
+rloop:
+	for i, receipt := range msg.Receipts {
+
+	eloop:
+		for j := range receipt.Events {
+			// try all events first
+			// if it exceeds limit, try again by removing last event
+			events := receipt.Events[:len(receipt.Events)-j]
+
+			rlpEvents, err := codec.RLP.MarshalToBytes(events)
+			if err != nil {
+				return nil, nil, err
+			}
+			rlpReceipt, err := codec.RLP.MarshalToBytes(&chain.RelayReceipt{
+				Index:  receipt.Index,
+				Height: receipt.Height,
+				Events: rlpEvents,
+			})
+			if err != nil {
+				return nil, nil, err
+			}
+
+			newMsgSize := msgSize + uint64(len(rlpReceipt))
+			if newMsgSize <= txDataSizeLimit {
+
+				msgSize = newMsgSize
+				if len(events) == len(receipt.Events) { // all events added
+					newMsg.Receipts = msg.Receipts[i+1:]
+				} else { // save remaining events in this receipt
+					receipt.Events = receipt.Events[len(events):]
+					newMsg.Receipts = msg.Receipts[i:]
+				}
+				relayMsg.Receipts = append(relayMsg.Receipts, rlpReceipt)
+				break eloop
+
+			} else if len(events) == 1 {
+				// stop iterating over receipts when adding even a single event
+				// exceeds tx size limit
+				break rloop
+			}
+
+		}
+	}
+
+	return relayMsg, newMsg, nil
+
+}