From b60d4ff19177bf0c8137dab50ce3d43090431ccc Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Fri, 18 Feb 2022 11:55:06 +0300
Subject: [PATCH] dao: deduplicate header->KV conversion

---
 pkg/core/blockchain.go | 16 +++++-----------
 pkg/core/dao/dao.go    | 27 ++++++++++++++++++++-------
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index b629a0373..9d127721f 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -932,7 +932,6 @@ func (bc *Blockchain) addHeaders(verify bool, headers ...*block.Header) error {
 		}
 	}
 
-	buf := io.NewBufBinWriter()
 	bc.headerHashesLock.Lock()
 	defer bc.headerHashesLock.Unlock()
 	oldlen := len(bc.headerHashes)
@@ -941,21 +940,16 @@ func (bc *Blockchain) addHeaders(verify bool, headers ...*block.Header) error {
 		if int(h.Index) != len(bc.headerHashes) {
 			continue
 		}
-		bc.headerHashes = append(bc.headerHashes, h.Hash())
-		buf.WriteB(storage.ExecBlock)
-		h.EncodeBinary(buf.BinWriter)
-		buf.BinWriter.WriteB(0)
-		if buf.Err != nil {
-			return buf.Err
+		err = batch.StoreHeader(h)
+		if err != nil {
+			return err
 		}
-
-		key := storage.AppendPrefix(storage.DataExecutable, h.Hash().BytesBE())
-		batch.Store.Put(key, buf.Bytes())
-		buf.Reset()
+		bc.headerHashes = append(bc.headerHashes, h.Hash())
 		lastHeader = h
 	}
 
 	if oldlen != len(bc.headerHashes) {
+		buf := io.NewBufBinWriter()
 		for int(lastHeader.Index)-headerBatchCount >= int(bc.storedHeaderCount) {
 			buf.WriteArray(bc.headerHashes[bc.storedHeaderCount : bc.storedHeaderCount+headerBatchCount])
 			if buf.Err != nil {
diff --git a/pkg/core/dao/dao.go b/pkg/core/dao/dao.go
index cd4221e1b..a69ac0355 100644
--- a/pkg/core/dao/dao.go
+++ b/pkg/core/dao/dao.go
@@ -668,14 +668,10 @@ func (dao *Simple) DeleteBlock(h util.Uint256) error {
 		return err
 	}
 
-	w := dao.getDataBuf()
-	w.WriteB(storage.ExecBlock)
-	b.Header.EncodeBinary(w.BinWriter)
-	w.BinWriter.WriteB(0)
-	if w.Err != nil {
-		return w.Err
+	err = dao.storeHeader(key, &b.Header)
+	if err != nil {
+		return err
 	}
-	dao.Store.Put(key, w.Bytes())
 
 	for _, tx := range b.Transactions {
 		copy(key[1:], tx.Hash().BytesBE())
@@ -692,6 +688,23 @@ func (dao *Simple) DeleteBlock(h util.Uint256) error {
 	return nil
 }
 
+// StoreHeader saves block header into the store.
+func (dao *Simple) StoreHeader(h *block.Header) error {
+	return dao.storeHeader(dao.makeExecutableKey(h.Hash()), h)
+}
+
+func (dao *Simple) storeHeader(key []byte, h *block.Header) error {
+	buf := dao.getDataBuf()
+	buf.WriteB(storage.ExecBlock)
+	h.EncodeBinary(buf.BinWriter)
+	buf.BinWriter.WriteB(0)
+	if buf.Err != nil {
+		return buf.Err
+	}
+	dao.Store.Put(key, buf.Bytes())
+	return nil
+}
+
 // StoreAsCurrentBlock stores a hash of the given block with prefix
 // SYSCurrentBlock. It can reuse given buffer for the purpose of value
 // serialization.