ava-labs
diff --git a/‎core/blockchain.go‎
Lines changed: 76 additions & 25 deletions b/‎core/blockchain.go‎
Lines changed: 76 additions & 25 deletions
@@ -178,7 +178,7 @@ type CacheConfig struct {
 	PopulateMissingTries            *uint64 // If non-nil, sets the starting height for re-generating historical tries.
 	PopulateMissingTriesParallelism int     // Number of readers to use when trying to populate missing tries.
 	AllowMissingTries               bool    // Whether to allow an archive node to run with pruning enabled
-	SnapshotDelayInit               bool    // Whether to initialize snapshots on startup or wait for external call
+	SnapshotDelayInit               bool    // Whether to initialize snapshots on startup or wait for external call (= StateSyncEnabled)
 	SnapshotLimit                   int     // Memory allowance (MB) to use for caching snapshot entries in memory
 	SnapshotVerify                  bool    // Verify generated snapshots
 	Preimages                       bool    // Whether to store preimage of trie key to the disk
@@ -335,6 +335,9 @@ type BlockChain struct {
 
 	// [acceptedLogsCache] stores recently accepted logs to improve the performance of eth_getLogs.
 	acceptedLogsCache FIFOCache[common.Hash, [][]*types.Log]
+
+	// [txIndexTailLock] is used to synchronize the updating of the tx index tail.
+	txIndexTailLock sync.Mutex
 }
 
 // NewBlockChain returns a fully initialised block chain using information
@@ -444,13 +447,32 @@ func NewBlockChain(
 	// Warm up [hc.acceptedNumberCache] and [acceptedLogsCache]
 	bc.warmAcceptedCaches()
 
+	// if txlookup limit is 0 (uindexing disabled), we don't need to repair the tx index tail.
+	if bc.cacheConfig.TxLookupLimit != 0 {
+		latestStateSynced := rawdb.GetLatestSyncPerformed(bc.db)
+		bc.setTxIndexTail(latestStateSynced)
+	}
+
 	// Start processing accepted blocks effects in the background
 	go bc.startAcceptor()
 
 	// Start tx indexer/unindexer if required.
 	if bc.cacheConfig.TxLookupLimit != 0 {
 		bc.wg.Add(1)
-		go bc.dispatchTxUnindexer()
+		var (
+			headCh = make(chan ChainEvent, 1) // Buffered to avoid locking up the event feed
+			sub    = bc.SubscribeChainAcceptedEvent(headCh)
+		)
+		go func() {
+			defer bc.wg.Done()
+			if sub == nil {
+				log.Warn("could not create chain accepted subscription to unindex txs")
+				return
+			}
+			defer sub.Unsubscribe()
+
+			bc.maintainTxIndex(headCh)
+		}()
 	}
 	return bc, nil
 }
@@ -459,9 +481,12 @@ func NewBlockChain(
 func (bc *BlockChain) unindexBlocks(tail uint64, head uint64, done chan struct{}) {
 	start := time.Now()
 	txLookupLimit := bc.cacheConfig.TxLookupLimit
+	bc.txIndexTailLock.Lock()
 	defer func() {
 		txUnindexTimer.Inc(time.Since(start).Milliseconds())
+		bc.txIndexTailLock.Unlock()
 		close(done)
+		bc.wg.Done()
 	}()
 
 	// If head is 0, it means the chain is just initialized and no blocks are inserted,
@@ -476,12 +501,11 @@ func (bc *BlockChain) unindexBlocks(tail uint64, head uint64, done chan struct{}
 	}
 }
 
-// dispatchTxUnindexer is responsible for the deletion of the
-// transaction index.
+// maintainTxIndex is responsible for the deletion of the
+// transaction index. This does not support reconstruction of removed indexes.
 // Invariant: If TxLookupLimit is 0, it means all tx indices will be preserved.
 // Meaning that this function should never be called.
-func (bc *BlockChain) dispatchTxUnindexer() {
-	defer bc.wg.Done()
+func (bc *BlockChain) maintainTxIndex(headCh <-chan ChainEvent) {
 	txLookupLimit := bc.cacheConfig.TxLookupLimit
 
 	// If the user just upgraded to a new version which supports transaction
@@ -492,26 +516,19 @@ func (bc *BlockChain) dispatchTxUnindexer() {
 
 	// Any reindexing done, start listening to chain events and moving the index window
 	var (
-		done   chan struct{}              // Non-nil if background unindexing or reindexing routine is active.
-		headCh = make(chan ChainEvent, 1) // Buffered to avoid locking up the event feed
+		done chan struct{} // Non-nil if background unindexing or reindexing routine is active.
 	)
-	sub := bc.SubscribeChainAcceptedEvent(headCh)
-	if sub == nil {
-		log.Warn("could not create chain accepted subscription to unindex txs")
-		return
-	}
-	defer sub.Unsubscribe()
 	log.Info("Initialized transaction unindexer", "limit", txLookupLimit)
 
-	// TODO: Uncomment this code when the tx-unindexer fix is ready.
 	// Launch the initial processing if chain is not empty. This step is
 	// useful in these scenarios that chain has no progress and indexer
 	// is never triggered.
-	// if head := bc.lastAccepted; head != nil && head.NumberU64() > txLookupLimit {
-	// 	done = make(chan struct{})
-	// 	tail := rawdb.ReadTxIndexTail(bc.db)
-	// 	go bc.unindexBlocks(*tail, head.NumberU64(), done)
-	// }
+	if head := bc.CurrentBlock(); head != nil && head.Number.Uint64() > txLookupLimit {
+		done = make(chan struct{})
+		tail := rawdb.ReadTxIndexTail(bc.db)
+		bc.wg.Add(1)
+		go bc.unindexBlocks(*tail, head.Number.Uint64(), done)
+	}
 
 	for {
 		select {
@@ -525,13 +542,14 @@ func (bc *BlockChain) dispatchTxUnindexer() {
 				done = make(chan struct{})
 				// Note: tail will not be nil since it is initialized in this function.
 				tail := rawdb.ReadTxIndexTail(bc.db)
+				bc.wg.Add(1)
 				go bc.unindexBlocks(*tail, headNum, done)
 			}
 		case <-done:
 			done = nil
 		case <-bc.quit:
 			if done != nil {
-				log.Info("Waiting background transaction indexer to exit")
+				log.Info("Waiting background transaction unindexer to exit")
 				<-done
 			}
 			return
@@ -545,15 +563,22 @@ func (bc *BlockChain) dispatchTxUnindexer() {
 // - updating the acceptor tip index
 func (bc *BlockChain) writeBlockAcceptedIndices(b *types.Block) error {
 	batch := bc.db.NewBatch()
+	if err := bc.batchBlockAcceptedIndices(batch, b); err != nil {
+		return err
+	}
+	if err := batch.Write(); err != nil {
+		return fmt.Errorf("%w: failed to write accepted indices entries batch", err)
+	}
+	return nil
+}
+
+func (bc *BlockChain) batchBlockAcceptedIndices(batch ethdb.Batch, b *types.Block) error {
 	if !bc.cacheConfig.SkipTxIndexing {
 		rawdb.WriteTxLookupEntriesByBlock(batch, b)
 	}
 	if err := rawdb.WriteAcceptorTip(batch, b.Hash()); err != nil {
 		return fmt.Errorf("%w: failed to write acceptor tip key", err)
 	}
-	if err := batch.Write(); err != nil {
-		return fmt.Errorf("%w: failed to write tx lookup entries batch", err)
-	}
 	return nil
 }
 
@@ -2164,6 +2189,8 @@ func (bc *BlockChain) gatherBlockRootsAboveLastAccepted() map[common.Hash]struct
 	return blockRoots
 }
 
+// TODO: split extras to blockchain_extra.go
+
 // ResetToStateSyncedBlock reinitializes the state of the blockchain
 // to the trie represented by [block.Root()] after updating
 // in-memory and on disk current block pointers to [block].
@@ -2174,7 +2201,9 @@ func (bc *BlockChain) ResetToStateSyncedBlock(block *types.Block) error {
 
 	// Update head block and snapshot pointers on disk
 	batch := bc.db.NewBatch()
-	rawdb.WriteAcceptorTip(batch, block.Hash())
+	if err := bc.batchBlockAcceptedIndices(batch, block); err != nil {
+		return err
+	}
 	rawdb.WriteHeadBlockHash(batch, block.Hash())
 	rawdb.WriteHeadHeaderHash(batch, block.Hash())
 	rawdb.WriteSnapshotBlockHash(batch, block.Hash())
@@ -2187,6 +2216,11 @@ func (bc *BlockChain) ResetToStateSyncedBlock(block *types.Block) error {
 		return err
 	}
 
+	// if txlookup limit is 0 (uindexing disabled), we don't need to repair the tx index tail.
+	if bc.cacheConfig.TxLookupLimit != 0 {
+		bc.setTxIndexTail(block.NumberU64())
+	}
+
 	// Update all in-memory chain markers
 	bc.lastAccepted = block
 	bc.acceptorTip = block
@@ -2219,3 +2253,20 @@ func (bc *BlockChain) ResetToStateSyncedBlock(block *types.Block) error {
 func (bc *BlockChain) CacheConfig() *CacheConfig {
 	return bc.cacheConfig
 }
+
+func (bc *BlockChain) setTxIndexTail(newTail uint64) error {
+	bc.txIndexTailLock.Lock()
+	defer bc.txIndexTailLock.Unlock()
+
+	tailP := rawdb.ReadTxIndexTail(bc.db)
+	var tailV uint64
+	if tailP != nil {
+		tailV = *tailP
+	}
+
+	if newTail > tailV {
+		log.Info("Repairing tx index tail", "old", tailV, "new", newTail)
+		rawdb.WriteTxIndexTail(bc.db, newTail)
+	}
+	return nil
+}