From 4b9b0cbcc1814e3956307d7003f1e76877802dae Mon Sep 17 00:00:00 2001
From: Yicheng Qin <qycqycqycqycqyc@gmail.com>
Date: Fri, 28 Aug 2015 22:03:32 -0700
Subject: [PATCH] storage: add newBackend and newBatchTx

This is for ease of testing.
---
 storage/backend/backend.go  | 8 +++++---
 storage/backend/batch_tx.go | 6 ++++++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/storage/backend/backend.go b/storage/backend/backend.go
index 9389d308d..0fb9f02eb 100644
--- a/storage/backend/backend.go
+++ b/storage/backend/backend.go
@@ -27,6 +27,10 @@ type backend struct {
 }
 
 func New(path string, d time.Duration, limit int) Backend {
+	return newBackend(path, d, limit)
+}
+
+func newBackend(path string, d time.Duration, limit int) *backend {
 	db, err := bolt.Open(path, 0600, nil)
 	if err != nil {
 		log.Panicf("backend: cannot open database at %s (%v)", path, err)
@@ -37,13 +41,11 @@ func New(path string, d time.Duration, limit int) Backend {
 
 		batchInterval: d,
 		batchLimit:    limit,
-		batchTx:       &batchTx{},
 
 		stopc: make(chan struct{}),
 		donec: make(chan struct{}),
 	}
-	b.batchTx.backend = b
-	b.batchTx.Commit()
+	b.batchTx = newBatchTx(b)
 	go b.run()
 	return b
 }
diff --git a/storage/backend/batch_tx.go b/storage/backend/batch_tx.go
index 92aced332..56797b85c 100644
--- a/storage/backend/batch_tx.go
+++ b/storage/backend/batch_tx.go
@@ -26,6 +26,12 @@ type batchTx struct {
 	pending int
 }
 
+func newBatchTx(backend *backend) *batchTx {
+	tx := &batchTx{backend: backend}
+	tx.Commit()
+	return tx
+}
+
 func (t *batchTx) UnsafeCreateBucket(name []byte) {
 	_, err := t.tx.CreateBucket(name)
 	if err != nil && err != bolt.ErrBucketExists {