core/filtermaps: safely revert reorged log index during init

core/filtermaps/chain_view.go

@@ -135,14 +135,6 @@ func (cv *ChainView) SharedRange(cv2 *ChainView) common.Range[uint64] {
 	return common.NewRange(0, sharedLen)
 }
 
-// limitedView returns a new chain view that is a truncated version of the parent view.
-func (cv *ChainView) limitedView(newHead uint64) *ChainView {
-	if newHead >= cv.headNumber {
-		return cv
-	}
-	return NewChainView(cv.chain, newHead, cv.BlockHash(newHead))
-}
-
 // equalViews returns true if the two chain views are equivalent.
 func equalViews(cv1, cv2 *ChainView) bool {
 	if cv1 == nil || cv2 == nil {

core/filtermaps/filtermaps.go

@@ -244,6 +244,8 @@ func NewFilterMaps(db ethdb.KeyValueStore, initView *ChainView, historyCutoff, f
 		disabledCh:        make(chan struct{}),
 		exportFileName:    config.ExportFileName,
 		Params:            params,
+		targetView:        initView,
+		indexedView:       initView,
 		indexedRange: filterMapsRange{
 			initialized:      initialized,
 			headIndexed:      rs.HeadIndexed,
@@ -265,16 +267,8 @@ func NewFilterMaps(db ethdb.KeyValueStore, initView *ChainView, historyCutoff, f
 		baseRowsCache:   lru.NewCache[uint64, [][]uint32](cachedBaseRows),
 		renderSnapshots: lru.NewCache[uint64, *renderedMap](cachedRenderSnapshots),
 	}
+	f.checkRevertRange() // revert maps that are inconsistent with the current chain view
 
-	// Set initial indexer target.
-	f.targetView = initView
-	if f.indexedRange.initialized {
-		f.indexedView = f.initChainView(f.targetView)
-		f.indexedRange.headIndexed = f.indexedRange.blocks.AfterLast() == f.indexedView.HeadNumber()+1
-		if !f.indexedRange.headIndexed {
-			f.indexedRange.headDelimiter = 0
-		}
-	}
 	if f.indexedRange.hasIndexedBlocks() {
 		log.Info("Initialized log indexer",
 			"first block", f.indexedRange.blocks.First(), "last block", f.indexedRange.blocks.Last(),
@@ -303,29 +297,40 @@ func (f *FilterMaps) Stop() {
 	f.closeWg.Wait()
 }
 
-// initChainView returns a chain view consistent with both the current target
-// view and the current state of the log index as found in the database, based
-// on the last block of stored maps.
-// Note that the returned view might be shorter than the existing index if
-// the latest maps are not consistent with targetView.
-func (f *FilterMaps) initChainView(chainView *ChainView) *ChainView {
-	mapIndex := f.indexedRange.maps.AfterLast()
-	for {
-		var ok bool
-		mapIndex, ok = f.lastMapBoundaryBefore(mapIndex)
-		if !ok {
-			break
-		}
-		lastBlockNumber, lastBlockId, err := f.getLastBlockOfMap(mapIndex)
-		if err != nil {
-			log.Error("Could not initialize indexed chain view", "error", err)
-			break
-		}
-		if lastBlockNumber <= chainView.HeadNumber() && chainView.BlockId(lastBlockNumber) == lastBlockId {
-			return chainView.limitedView(lastBlockNumber)
-		}
+// checkRevertRange checks whether the existing index is consistent with the
+// current indexed view and reverts inconsistent maps if necessary.
+func (f *FilterMaps) checkRevertRange() {
+	if f.indexedRange.maps.Count() == 0 {
+		return
+	}
+	lastMap := f.indexedRange.maps.Last()
+	lastBlockNumber, lastBlockId, err := f.getLastBlockOfMap(lastMap)
+	if err != nil {
+		log.Error("Error initializing log index database; resetting log index", "error", err)
+		f.reset()
+		return
+	}
+	for lastBlockNumber > f.indexedView.HeadNumber() || f.indexedView.BlockId(lastBlockNumber) != lastBlockId {
+		// revert last map
+		if f.indexedRange.maps.Count() == 1 {
+			f.reset() // reset database if no rendered maps remained
+			return
+		}
+		lastMap--
+		newRange := f.indexedRange
+		newRange.maps.SetLast(lastMap)
+		lastBlockNumber, lastBlockId, err = f.getLastBlockOfMap(lastMap)
+		if err != nil {
+			log.Error("Error initializing log index database; resetting log index", "error", err)
+			f.reset()
+			return
+		}
+		newRange.blocks.SetAfterLast(lastBlockNumber) // lastBlockNumber is probably partially indexed
+		newRange.headIndexed = false
+		newRange.headDelimiter = 0
+		// only shorten range and leave map data; next head render will overwrite it
+		f.setRange(f.db, f.indexedView, newRange, false)
 	}
-	return chainView.limitedView(0)
 }
 
 // reset un-initializes the FilterMaps structure and removes all related data from

core/filtermaps/map_renderer.go

@@ -473,7 +473,7 @@ func (r *mapRenderer) writeFinishedMaps(pauseCb func() bool) error {
 		// in order to always ensure continuous block pointers, initialize
 		// blockNumber based on the last block of the previous map, then verify
 		// against the first block associated with each rendered map
-		lastBlock, _, err := r.f.getLastBlockOfMap(r.finished.First()-1)
+		lastBlock, _, err := r.f.getLastBlockOfMap(r.finished.First() - 1)
 		if err != nil {
 			return fmt.Errorf("failed to get last block of previous map %d: %v", r.finished.First()-1, err)
 		}