core, ethdb, triedb: add batch close

core/blockchain.go

@@ -1276,6 +1276,8 @@ func (bc *BlockChain) ExportN(w io.Writer, first uint64, last uint64) error {
 func (bc *BlockChain) writeHeadBlock(block *types.Block) {
 	// Add the block to the canonical chain number scheme and mark as the head
 	batch := bc.db.NewBatch()
+	defer batch.Close()
+
 	rawdb.WriteHeadHeaderHash(batch, block.Hash())
 	rawdb.WriteHeadFastBlockHash(batch, block.Hash())
 	rawdb.WriteCanonicalHash(batch, block.Hash(), block.NumberU64())
@@ -1650,6 +1652,8 @@ func (bc *BlockChain) writeBlockWithState(block *types.Block, receipts []*types.
 		batch = bc.db.NewBatch()
 		start = time.Now()
 	)
+	defer batch.Close()
+
 	rawdb.WriteBlock(batch, block)
 	rawdb.WriteReceipts(batch, block.Hash(), block.NumberU64(), receipts)
 	rawdb.WritePreimages(batch, statedb.Preimages())
@@ -2628,6 +2632,8 @@ func (bc *BlockChain) reorg(oldHead *types.Header, newHead *types.Header) error
 	// Delete useless indexes right now which includes the non-canonical
 	// transaction indexes, canonical chain indexes which above the head.
 	batch := bc.db.NewBatch()
+	defer batch.Close()
+
 	for _, tx := range types.HashDifference(deletedTxs, rebirthTxs) {
 		rawdb.DeleteTxLookupEntry(batch, tx)
 	}

core/rawdb/table.go

@@ -253,6 +253,11 @@ func (b *tableBatch) Reset() {
 	b.batch.Reset()
 }
 
+// Close closes the batch and releases all associated resources.
+func (b *tableBatch) Close() {
+	b.batch.Close()
+}
+
 // tableReplayer is a wrapper around a batch replayer which truncates
 // the added prefix.
 type tableReplayer struct {

core/state/statedb.go

@@ -1333,6 +1333,7 @@ func (s *StateDB) commitAndFlush(block uint64, deleteEmptyObjects bool, noStorag
 		if err := batch.Write(); err != nil {
 			return nil, err
 		}
+		batch.Close()
 	}
 	if !ret.empty() {
 		// If snapshotting is enabled, update the snapshot tree with this new version

ethdb/batch.go

@@ -37,6 +37,9 @@ type Batch interface {
 
 	// Replay replays the batch contents.
 	Replay(w KeyValueWriter) error
+
+	// Close closes the batch and releases all associated resources.
+	Close()
 }
 
 // Batcher wraps the NewBatch method of a backing data store.

ethdb/leveldb/leveldb.go

@@ -518,6 +518,9 @@ func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 	return b.b.Replay(&replayer{writer: w})
 }
 
+// Close closes the batch and releases all associated resources.
+func (b *batch) Close() {}
+
 // replayer is a small wrapper to implement the correct replay methods.
 type replayer struct {
 	writer  ethdb.KeyValueWriter

ethdb/memorydb/memorydb.go

@@ -338,6 +338,9 @@ func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 	return nil
 }
 
+// Close closes the batch and releases all associated resources.
+func (b *batch) Close() {}
+
 // iterator can walk over the (potentially partial) keyspace of a memory key
 // value store. Internally it is a deep copy of the entire iterated state,
 // sorted by keys.

ethdb/pebble/pebble.go

@@ -727,6 +727,12 @@ func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 	}
 }
 
+// Close closes the batch and releases all associated resources. After it is
+// closed, any subsequent operations on this batch are undefined.
+func (b *batch) Close() {
+	b.b.Close()
+}
+
 // pebbleIterator is a wrapper of underlying iterator in storage engine.
 // The purpose of this structure is to implement the missing APIs.
 //

trie/trie_test.go

@@ -880,6 +880,7 @@ func (b *spongeBatch) ValueSize() int                      { return 100 }
 func (b *spongeBatch) Write() error                        { return nil }
 func (b *spongeBatch) Reset()                              {}
 func (b *spongeBatch) Replay(w ethdb.KeyValueWriter) error { return nil }
+func (b *spongeBatch) Close()                              {}
 
 // TestCommitSequence tests that the trie.Commit operation writes the elements
 // of the trie in the expected order.

triedb/pathdb/buffer.go

@@ -180,6 +180,8 @@ func (b *buffer) flush(root common.Hash, db ethdb.KeyValueStore, freezers []ethd
 			b.flushErr = err
 			return
 		}
+		batch.Close()
+
 		commitBytesMeter.Mark(int64(size))
 		commitNodesMeter.Mark(int64(nodes))
 		commitAccountsMeter.Mark(int64(accounts))