From 20bac87d6064b7d4ffbcb0e49f3703058d0ba820 Mon Sep 17 00:00:00 2001
From: dongxu <i@huangdx.net>
Date: Tue, 22 Sep 2015 17:51:41 +0800
Subject: [PATCH] kv : Add some comments, add release interface

address code review comments
---
 kv/kv.go                      | 4 +++-
 store/localstore/mvcc_test.go | 2 ++
 store/localstore/snapshot.go  | 4 ++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/kv/kv.go b/kv/kv.go
index 0e3f52c08b..7c8c5c4d0d 100644
--- a/kv/kv.go
+++ b/kv/kv.go
@@ -129,6 +129,8 @@ type MvccSnapshot interface {
 	// MvccIterator seeks to the key in the specific version's snapshot, if the
 	// version doesn't exists, return the nearest(lower) version's snaphot.
 	NewMvccIterator(k Key, ver Version) Iterator
+	// Release releases this snapshot.
+	MvccRelease()
 }
 
 // Snapshot defines the interface for the snapshot fetched from KV store.
@@ -153,7 +155,7 @@ type Driver interface {
 type Storage interface {
 	// Begin transaction
 	Begin() (Transaction, error)
-	// MvccSnapshot get a snaphot that cloud read any version of data.
+	// MvccSnapshot get a snaphot that is able to read any version of data.
 	GetMvccSnapshot() (MvccSnapshot, error)
 	// Close store
 	Close() error
diff --git a/store/localstore/mvcc_test.go b/store/localstore/mvcc_test.go
index f5bd55f84c..5b02b97765 100644
--- a/store/localstore/mvcc_test.go
+++ b/store/localstore/mvcc_test.go
@@ -154,6 +154,7 @@ func (t *testMvccSuite) TestMvccSnapshotGet(c *C) {
 	c.Assert(err, IsNil)
 
 	mvccSnapshot, err := t.s.GetMvccSnapshot()
+	defer mvccSnapshot.MvccRelease()
 	b, err = mvccSnapshot.MvccGet(kv.EncodeKey(encodeInt(1)), kv.MaxVersion)
 	c.Assert(err, IsNil)
 	c.Assert(string(b), Equals, "new")
@@ -178,6 +179,7 @@ func (t *testMvccSuite) TestMvccSnapshotScan(c *C) {
 	c.Assert(err, IsNil)
 
 	mvccSnapshot, err := t.s.GetMvccSnapshot()
+	defer mvccSnapshot.MvccRelease()
 	c.Assert(err, IsNil)
 
 	// iter helper function
diff --git a/store/localstore/snapshot.go b/store/localstore/snapshot.go
index 3f835a1f5b..37a882db5d 100644
--- a/store/localstore/snapshot.go
+++ b/store/localstore/snapshot.go
@@ -95,6 +95,10 @@ func (s *dbSnapshot) NewIterator(param interface{}) kv.Iterator {
 	return newDBIter(s, k, kv.MaxVersion)
 }
 
+func (s *dbSnapshot) MvccRelease() {
+	s.Release()
+}
+
 func (s *dbSnapshot) Release() {
 	if s.Snapshot != nil {
 		s.Snapshot.Release()