l2geth: add `VerifiedIndex` to DB and API (#520)

* l2geth: add verified index to db and api

* l2geth: add patch changeset

.changeset/thin-dodos-reply.md

+---
+"@eth-optimism/l2geth": patch
+---
+
+Add `VerifiedIndex` to db and api

l2geth/core/rawdb/rollup_indexes.go

@@ -7,6 +7,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 )
 
+// ReadHeadIndex will read the known tip of the CTC
 func ReadHeadIndex(db ethdb.KeyValueReader) *uint64 {
 	data, _ := db.Get(headIndexKey)
 	if len(data) == 0 {
@@ -16,6 +17,7 @@ func ReadHeadIndex(db ethdb.KeyValueReader) *uint64 {
 	return &ret
 }
 
+// WriteHeadIndex will write the known tip of the CTC
 func WriteHeadIndex(db ethdb.KeyValueWriter, index uint64) {
 	value := new(big.Int).SetUint64(index).Bytes()
 	if index == 0 {
@@ -26,6 +28,7 @@ func WriteHeadIndex(db ethdb.KeyValueWriter, index uint64) {
 	}
 }
 
+// ReadHeadQueueIndex will read the known tip of the queue
 func ReadHeadQueueIndex(db ethdb.KeyValueReader) *uint64 {
 	data, _ := db.Get(headQueueIndexKey)
 	if len(data) == 0 {
@@ -35,6 +38,7 @@ func ReadHeadQueueIndex(db ethdb.KeyValueReader) *uint64 {
 	return &ret
 }
 
+// WriteHeadQueueIndex will write the known tip of the queue
 func WriteHeadQueueIndex(db ethdb.KeyValueWriter, index uint64) {
 	value := new(big.Int).SetUint64(index).Bytes()
 	if index == 0 {
@@ -44,3 +48,24 @@ func WriteHeadQueueIndex(db ethdb.KeyValueWriter, index uint64) {
 		log.Crit("Failed to store queue index", "err", err)
 	}
 }
+
+// ReadHeadVerifiedIndex will read the known tip of the batched transactions
+func ReadHeadVerifiedIndex(db ethdb.KeyValueReader) *uint64 {
+	data, _ := db.Get(headVerifiedIndexKey)
+	if len(data) == 0 {
+		return nil
+	}
+	ret := new(big.Int).SetBytes(data).Uint64()
+	return &ret
+}
+
+// WriteHeadVerifiedIndex will write the known tip of the batched transactions
+func WriteHeadVerifiedIndex(db ethdb.KeyValueWriter, index uint64) {
+	value := new(big.Int).SetUint64(index).Bytes()
+	if index == 0 {
+		value = []byte{0}
+	}
+	if err := db.Put(headVerifiedIndexKey, value); err != nil {
+		log.Crit("Failed to store verifier index", "err", err)
+	}
+}

l2geth/core/rawdb/schema.go

@@ -60,6 +60,8 @@ var (
 	headIndexKey = []byte("LastIndex")
 	// headQueueIndexKey tracks th last processed queue index
 	headQueueIndexKey = []byte("LastQueueIndex")
+	// headVerifiedIndexKey tracks the latest verified index
+	headVerifiedIndexKey = []byte("LastVerifiedIndex")
 
 	preimagePrefix = []byte("secure-key-")      // preimagePrefix + hash -> preimage
 	configPrefix   = []byte("ethereum-config-") // config prefix for the db

l2geth/eth/api_backend.go

@@ -71,18 +71,21 @@ func (b *EthAPIBackend) GetEthContext() (uint64, uint64) {
 	return bn, ts
 }
 
-func (b *EthAPIBackend) GetRollupContext() (uint64, uint64) {
-	i := uint64(0)
-	q := uint64(0)
-	index := b.eth.syncService.GetLatestIndex()
-	if index != nil {
-		i = *index
+func (b *EthAPIBackend) GetRollupContext() (uint64, uint64, uint64) {
+	index := uint64(0)
+	queueIndex := uint64(0)
+	verifiedIndex := uint64(0)
+
+	if latest := b.eth.syncService.GetLatestIndex(); latest != nil {
+		index = *latest
+	}
+	if latest := b.eth.syncService.GetLatestEnqueueIndex(); latest != nil {
+		queueIndex = *latest
 	}
-	queueIndex := b.eth.syncService.GetLatestEnqueueIndex()
-	if queueIndex != nil {
-		q = *queueIndex
+	if latest := b.eth.syncService.GetLatestVerifiedIndex(); latest != nil {
+		verifiedIndex = *latest
 	}
-	return i, q
+	return index, queueIndex, verifiedIndex
 }
 
 // ChainConfig returns the active chain configuration.

l2geth/internal/ethapi/api.go

@@ -1913,9 +1913,15 @@ type EthContext struct {
 	BlockNumber uint64 `json:"blockNumber"`
 	Timestamp   uint64 `json:"timestamp"`
 }
+
+// RollupContext represents the height of the rollup.
+// Index is the last processed CanonicalTransactionChain index
+// QueueIndex is the last processed `enqueue` index
+// VerifiedIndex is the last processed CTC index that was batched
 type RollupContext struct {
-	Index      uint64 `json:"index"`
-	QueueIndex uint64 `json:"queueIndex"`
+	Index         uint64 `json:"index"`
+	QueueIndex    uint64 `json:"queueIndex"`
+	VerifiedIndex uint64 `json:"verifiedIndex"`
 }
 
 type rollupInfo struct {
@@ -1932,7 +1938,7 @@ func (api *PublicRollupAPI) GetInfo(ctx context.Context) rollupInfo {
 	}
 	syncing := api.b.IsSyncing()
 	bn, ts := api.b.GetEthContext()
-	index, queueIndex := api.b.GetRollupContext()
+	index, queueIndex, verifiedIndex := api.b.GetRollupContext()
 
 	return rollupInfo{
 		Mode:    mode,
@@ -1942,8 +1948,9 @@ func (api *PublicRollupAPI) GetInfo(ctx context.Context) rollupInfo {
 			Timestamp:   ts,
 		},
 		RollupContext: RollupContext{
-			Index:      index,
-			QueueIndex: queueIndex,
+			Index:         index,
+			QueueIndex:    queueIndex,
+			VerifiedIndex: verifiedIndex,
 		},
 	}
 }

l2geth/internal/ethapi/backend.go

@@ -91,7 +91,7 @@ type Backend interface {
 	IsVerifier() bool
 	IsSyncing() bool
 	GetEthContext() (uint64, uint64)
-	GetRollupContext() (uint64, uint64)
+	GetRollupContext() (uint64, uint64, uint64)
 	GasLimit() uint64
 	GetDiff(*big.Int) (diffdb.Diff, error)
 	SuggestDataPrice(ctx context.Context) (*big.Int, error)

l2geth/les/api_backend.go

@@ -58,8 +58,8 @@ func (b *LesApiBackend) GetEthContext() (uint64, uint64) {
 	return 0, 0
 }
 
-func (b *LesApiBackend) GetRollupContext() (uint64, uint64) {
-	return 0, 0
+func (b *LesApiBackend) GetRollupContext() (uint64, uint64, uint64) {
+	return 0, 0, 0
 }
 
 func (b *LesApiBackend) IsSyncing() bool {

l2geth/rollup/sync_service.go

@@ -548,40 +548,90 @@ func (s *SyncService) syncTransactionsToTip() error {
 
 // Methods for safely accessing and storing the latest
 // L1 blocknumber and timestamp. These are held in memory.
+
+// GetLatestL1Timestamp returns the OVMContext timestamp
 func (s *SyncService) GetLatestL1Timestamp() uint64 {
 	return atomic.LoadUint64(&s.OVMContext.timestamp)
 }
 
+// GetLatestL1BlockNumber returns the OVMContext blocknumber
 func (s *SyncService) GetLatestL1BlockNumber() uint64 {
 	return atomic.LoadUint64(&s.OVMContext.blockNumber)
 }
 
+// SetLatestL1Timestamp will set the OVMContext timestamp
 func (s *SyncService) SetLatestL1Timestamp(ts uint64) {
 	atomic.StoreUint64(&s.OVMContext.timestamp, ts)
 }
 
+// SetLatestL1BlockNumber will set the OVMContext blocknumber
 func (s *SyncService) SetLatestL1BlockNumber(bn uint64) {
 	atomic.StoreUint64(&s.OVMContext.blockNumber, bn)
 }
 
+// GetLatestEnqueueIndex reads the last queue index processed
 func (s *SyncService) GetLatestEnqueueIndex() *uint64 {
 	return rawdb.ReadHeadQueueIndex(s.db)
 }
 
+// GetNextEnqueueIndex returns the next queue index to process
+func (s *SyncService) GetNextEnqueueIndex() uint64 {
+	latest := s.GetLatestEnqueueIndex()
+	if latest == nil {
+		return 0
+	}
+	return *latest + 1
+}
+
+// SetLatestEnqueueIndex writes the last queue index that was processed
 func (s *SyncService) SetLatestEnqueueIndex(index *uint64) {
 	if index != nil {
 		rawdb.WriteHeadQueueIndex(s.db, *index)
 	}
 }
 
+// GetLatestIndex reads the last CTC index that was processed
+func (s *SyncService) GetLatestIndex() *uint64 {
+	return rawdb.ReadHeadIndex(s.db)
+}
+
+// GetNextIndex reads the next CTC index to process
+func (s *SyncService) GetNextIndex() uint64 {
+	latest := s.GetLatestIndex()
+	if latest == nil {
+		return 0
+	}
+	return *latest + 1
+}
+
+// SetLatestIndex writes the last CTC index that was processed
 func (s *SyncService) SetLatestIndex(index *uint64) {
 	if index != nil {
 		rawdb.WriteHeadIndex(s.db, *index)
 	}
 }
 
-func (s *SyncService) GetLatestIndex() *uint64 {
-	return rawdb.ReadHeadIndex(s.db)
+// GetLatestVerifiedIndex reads the last verified CTC index that was processed
+// These are set by processing batches of transactions that were submitted to
+// the Canonical Transaction Chain.
+func (s *SyncService) GetLatestVerifiedIndex() *uint64 {
+	return rawdb.ReadHeadVerifiedIndex(s.db)
+}
+
+// GetNextVerifiedIndex reads the next verified index
+func (s *SyncService) GetNextVerifiedIndex() uint64 {
+	index := s.GetLatestVerifiedIndex()
+	if index == nil {
+		return 0
+	}
+	return *index + 1
+}
+
+// SetLatestVerifiedIndex writes the last verified index that was processed
+func (s *SyncService) SetLatestVerifiedIndex(index *uint64) {
+	if index != nil {
+		rawdb.WriteHeadVerifiedIndex(s.db, *index)
+	}
 }
 
 // reorganize will reorganize to directly to the index passed in.