From 017b9f7eacd1048661b22b7892caf680deb2b548 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Tue, 30 Jan 2018 18:03:31 +0100
Subject: [PATCH] core, ethdb: reuse database batches (#15989)

* leveldb: Update leveldb to 211f780 (poolfix)

* core, ethdb: reuse database batches
---
 core/blockchain.go       | 2 +-
 ethdb/database.go        | 8 ++++++++
 ethdb/interface.go       | 2 ++
 ethdb/memory_database.go | 5 +++++
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/core/blockchain.go b/core/blockchain.go
index f886ffe4e..1bda95231 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -749,7 +749,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 				return 0, err
 			}
 			bytes += batch.ValueSize()
-			batch = bc.chainDb.NewBatch()
+			batch.Reset()
 		}
 	}
 	if batch.ValueSize() > 0 {
diff --git a/ethdb/database.go b/ethdb/database.go
index 93755dd7e..9a7c85d9e 100644
--- a/ethdb/database.go
+++ b/ethdb/database.go
@@ -299,6 +299,10 @@ func (b *ldbBatch) ValueSize() int {
 	return b.size
 }
 
+func (b *ldbBatch) Reset() {
+	b.b.Reset()
+}
+
 type table struct {
 	db     Database
 	prefix string
@@ -358,3 +362,7 @@ func (tb *tableBatch) Write() error {
 func (tb *tableBatch) ValueSize() int {
 	return tb.batch.ValueSize()
 }
+
+func (tb *tableBatch) Reset() {
+	tb.batch.Reset()
+}
diff --git a/ethdb/interface.go b/ethdb/interface.go
index 99a5b770d..537312003 100644
--- a/ethdb/interface.go
+++ b/ethdb/interface.go
@@ -41,4 +41,6 @@ type Batch interface {
 	Putter
 	ValueSize() int // amount of data in the batch
 	Write() error
+	// Reset resets the batch for reuse
+	Reset()
 }
diff --git a/ethdb/memory_database.go b/ethdb/memory_database.go
index 0dd93a279..8efd7bf84 100644
--- a/ethdb/memory_database.go
+++ b/ethdb/memory_database.go
@@ -123,3 +123,8 @@ func (b *memBatch) Write() error {
 func (b *memBatch) ValueSize() int {
 	return b.size
 }
+
+func (b *memBatch) Reset() {
+	b.writes = b.writes[:0]
+	b.size = 0
+}