From 07e421d245a94b50b904cee53a020e61eb288fa0 Mon Sep 17 00:00:00 2001
From: Xiang Li <xiangli.cs@gmail.com>
Date: Thu, 4 Aug 2016 08:06:33 -0700
Subject: [PATCH] lease: delete kvs in a txn

---
 lease/lessor.go      | 20 +++++++++++++++++---
 lease/lessor_test.go | 12 ++++++++++--
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/lease/lessor.go b/lease/lessor.go
index 13c3f1b12..28708b313 100644
--- a/lease/lessor.go
+++ b/lease/lessor.go
@@ -45,13 +45,18 @@ var (
 
 type LeaseID int64
 
-// RangeDeleter defines an interface with DeleteRange method.
+// RangeDeleter defines an interface with Txn and DeleteRange method.
 // We define this interface only for lessor to limit the number
 // of methods of mvcc.KV to what lessor actually needs.
 //
 // Having a minimum interface makes testing easy.
 type RangeDeleter interface {
-	DeleteRange(key, end []byte) (int64, int64)
+	// TxnBegin see comments on mvcc.KV
+	TxnBegin() int64
+	// TxnEnd see comments on mvcc.KV
+	TxnEnd(txnID int64) error
+	// TxnDeleteRange see comments on mvcc.KV
+	TxnDeleteRange(txnID int64, key, end []byte) (n, rev int64, err error)
 }
 
 // Lessor owns leases. It can grant, revoke, renew and modify leases for lessee.
@@ -212,8 +217,17 @@ func (le *lessor) Revoke(id LeaseID) error {
 	le.mu.Unlock()
 
 	if le.rd != nil {
+		tid := le.rd.TxnBegin()
 		for item := range l.itemSet {
-			le.rd.DeleteRange([]byte(item.Key), nil)
+			_, _, err := le.rd.TxnDeleteRange(tid, []byte(item.Key), nil)
+			if err != nil {
+				panic(err)
+			}
+		}
+
+		err := le.rd.TxnEnd(tid)
+		if err != nil {
+			panic(err)
 		}
 	}
 
diff --git a/lease/lessor_test.go b/lease/lessor_test.go
index a9b7add61..f25c2ff6b 100644
--- a/lease/lessor_test.go
+++ b/lease/lessor_test.go
@@ -223,9 +223,17 @@ type fakeDeleter struct {
 	deleted []string
 }
 
-func (fd *fakeDeleter) DeleteRange(key, end []byte) (int64, int64) {
+func (fd *fakeDeleter) TxnBegin() int64 {
+	return 0
+}
+
+func (fd *fakeDeleter) TxnEnd(txnID int64) error {
+	return nil
+}
+
+func (fd *fakeDeleter) TxnDeleteRange(tid int64, key, end []byte) (int64, int64, error) {
 	fd.deleted = append(fd.deleted, string(key)+"_"+string(end))
-	return 0, 0
+	return 0, 0, nil
 }
 
 func NewTestBackend(t *testing.T) (string, backend.Backend) {