From 7223caf36953efd597303f3c7cd7a2aa91831c6c Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Fri, 18 Feb 2022 15:04:57 +0300
Subject: [PATCH] dao: improve PutCurrentHeader logic

Move serialization out of the core.
---
 pkg/core/blockchain.go | 11 ++---------
 pkg/core/dao/dao.go    |  7 +++++--
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index 346905870..624b9932c 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -325,7 +325,7 @@ func (bc *Blockchain) init() error {
 			return err
 		}
 		bc.headerHashes = []util.Uint256{genesisBlock.Hash()}
-		bc.dao.PutCurrentHeader(hashAndIndexToBytes(genesisBlock.Hash(), genesisBlock.Index))
+		bc.dao.PutCurrentHeader(genesisBlock.Hash(), genesisBlock.Index)
 		if err := bc.stateRoot.Init(0); err != nil {
 			return fmt.Errorf("can't init MPT: %w", err)
 		}
@@ -958,7 +958,7 @@ func (bc *Blockchain) addHeaders(verify bool, headers ...*block.Header) error {
 			bc.storedHeaderCount += headerBatchCount
 		}
 
-		batch.Store.Put(storage.SYSCurrentHeader.Bytes(), hashAndIndexToBytes(lastHeader.Hash(), lastHeader.Index))
+		batch.PutCurrentHeader(lastHeader.Hash(), lastHeader.Index)
 		updateHeaderHeightMetric(len(bc.headerHashes) - 1)
 		if _, err = batch.Persist(); err != nil {
 			return err
@@ -2299,13 +2299,6 @@ func (bc *Blockchain) ManagementContractHash() util.Uint160 {
 	return bc.contracts.Management.Hash
 }
 
-func hashAndIndexToBytes(h util.Uint256, index uint32) []byte {
-	buf := io.NewBufBinWriter()
-	buf.WriteBytes(h.BytesLE())
-	buf.WriteU32LE(index)
-	return buf.Bytes()
-}
-
 func (bc *Blockchain) newInteropContext(trigger trigger.Type, d *dao.Simple, block *block.Block, tx *transaction.Transaction) *interop.Context {
 	ic := interop.NewContext(trigger, bc, d, bc.contracts.Management.GetContract, bc.contracts.Contracts, block, tx, bc.log)
 	ic.Functions = systemInterops
diff --git a/pkg/core/dao/dao.go b/pkg/core/dao/dao.go
index af781d713..4b7520d45 100644
--- a/pkg/core/dao/dao.go
+++ b/pkg/core/dao/dao.go
@@ -559,8 +559,11 @@ func (dao *Simple) PutVersion(v Version) {
 }
 
 // PutCurrentHeader stores current header.
-func (dao *Simple) PutCurrentHeader(hashAndIndex []byte) {
-	dao.Store.Put(storage.SYSCurrentHeader.Bytes(), hashAndIndex)
+func (dao *Simple) PutCurrentHeader(h util.Uint256, index uint32) {
+	buf := dao.getDataBuf()
+	buf.WriteBytes(h.BytesLE())
+	buf.WriteU32LE(index)
+	dao.Store.Put(storage.SYSCurrentHeader.Bytes(), buf.Bytes())
 }
 
 // PutStateSyncPoint stores current state synchronisation point P.