From f5a60c321d3eab43c4323e87a8f24323742983d3 Mon Sep 17 00:00:00 2001
From: satoru <satorulogic@gmail.com>
Date: Thu, 28 Mar 2019 13:46:11 +0800
Subject: [PATCH] pump: Extract function and add unit tests (#503)

---
 pump/storage/storage.go      | 52 +++++++++++++++++++-----------------
 pump/storage/storage_test.go | 29 ++++++++++++++++++++
 2 files changed, 56 insertions(+), 25 deletions(-)

diff --git a/pump/storage/storage.go b/pump/storage/storage.go
index bb0005393..0a977b198 100644
--- a/pump/storage/storage.go
+++ b/pump/storage/storage.go
@@ -94,13 +94,12 @@ func NewAppend(dir string, options *Options) (append *Append, err error) {
 }
 
 // NewAppendWithResolver returns a instance of Append
-// if tiStore and tiLockResolver is not nil, we will try to query tikv to know weather a txn is committed
+// if tiStore and tiLockResolver is not nil, we will try to query tikv to know whether a txn is committed
 func NewAppendWithResolver(dir string, options *Options, tiStore kv.Storage, tiLockResolver *tikv.LockResolver) (append *Append, err error) {
 	if options == nil {
 		options = DefaultOptions()
 	}
 
-	kvDir := path.Join(dir, "kv")
 	valueDir := path.Join(dir, "value")
 	err = os.MkdirAll(valueDir, 0755)
 	if err != nil {
@@ -113,28 +112,8 @@ func NewAppendWithResolver(dir string, options *Options, tiStore kv.Storage, tiL
 		return nil, errors.Trace(err)
 	}
 
-	var opt opt.Options
-	cf := options.Storage
-	if cf == nil {
-		cf = defaultStorageConfig
-	} else {
-		setDefaultStorageConfig(cf)
-	}
-
-	log.Infof("storage config: %+v", cf)
-
-	opt.BlockCacheCapacity = cf.BlockCacheCapacity
-	opt.BlockRestartInterval = cf.BlockRestartInterval
-	opt.BlockSize = cf.BlockSize
-	opt.CompactionL0Trigger = cf.CompactionL0Trigger
-	opt.CompactionTableSize = cf.CompactionTableSize
-	opt.CompactionTotalSize = cf.CompactionTotalSize
-	opt.CompactionTotalSizeMultiplier = cf.CompactionTotalSizeMultiplier
-	opt.WriteBuffer = cf.WriteBuffer
-	opt.WriteL0PauseTrigger = cf.WriteL0PauseTrigger
-	opt.WriteL0SlowdownTrigger = cf.WriteL0SlowdownTrigger
-
-	metadata, err := leveldb.OpenFile(kvDir, &opt)
+	kvDir := path.Join(dir, "kv")
+	metadata, err := openMetadataDB(kvDir, options.Storage)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
@@ -229,7 +208,6 @@ func NewAppendWithResolver(dir string, options *Options, tiStore kv.Storage, tiL
 
 	append.wg.Add(1)
 	go append.updateStatus()
-
 	return
 }
 
@@ -1078,3 +1056,27 @@ func setDefaultStorageConfig(cf *Config) {
 		cf.WriteL0SlowdownTrigger = defaultStorageConfig.WriteL0SlowdownTrigger
 	}
 }
+
+func openMetadataDB(kvDir string, cf *Config) (*leveldb.DB, error) {
+	if cf == nil {
+		cf = defaultStorageConfig
+	} else {
+		setDefaultStorageConfig(cf)
+	}
+
+	log.Infof("Storage config: %+v", cf)
+
+	var opt opt.Options
+	opt.BlockCacheCapacity = cf.BlockCacheCapacity
+	opt.BlockRestartInterval = cf.BlockRestartInterval
+	opt.BlockSize = cf.BlockSize
+	opt.CompactionL0Trigger = cf.CompactionL0Trigger
+	opt.CompactionTableSize = cf.CompactionTableSize
+	opt.CompactionTotalSize = cf.CompactionTotalSize
+	opt.CompactionTotalSizeMultiplier = cf.CompactionTotalSizeMultiplier
+	opt.WriteBuffer = cf.WriteBuffer
+	opt.WriteL0PauseTrigger = cf.WriteL0PauseTrigger
+	opt.WriteL0SlowdownTrigger = cf.WriteL0SlowdownTrigger
+
+	return leveldb.OpenFile(kvDir, &opt)
+}
diff --git a/pump/storage/storage_test.go b/pump/storage/storage_test.go
index 4386b657c..e8fe61fe6 100644
--- a/pump/storage/storage_test.go
+++ b/pump/storage/storage_test.go
@@ -305,3 +305,32 @@ func (as *AppendSuit) TestResolve(c *check.C) {
 	// TODO test the case we query tikv to know weather a txn a commit
 	// is there a fake or mock kv.Storage and tikv.LockResolver to easy the test?
 }
+
+type OpenDBSuit struct {
+	dir string
+}
+
+var _ = check.Suite(&OpenDBSuit{})
+
+func (s *OpenDBSuit) SetUpTest(c *check.C) {
+	s.dir = c.MkDir()
+}
+
+func (s *OpenDBSuit) TestWhenConfigIsNotProvided(c *check.C) {
+	_, err := openMetadataDB(s.dir, nil)
+	c.Assert(err, check.IsNil)
+}
+
+func (s *OpenDBSuit) TestProvidedConfigValsNotOverwritten(c *check.C) {
+	cf := Config{
+		KVConfig: KVConfig{
+			BlockRestartInterval: 32,
+			WriteL0PauseTrigger:  12,
+		},
+	}
+	_, err := openMetadataDB(s.dir, &cf)
+	c.Assert(err, check.IsNil)
+	c.Assert(cf.BlockRestartInterval, check.Equals, 32)
+	c.Assert(cf.WriteL0PauseTrigger, check.Equals, 12)
+	c.Assert(cf.BlockCacheCapacity, check.Equals, defaultStorageConfig.BlockCacheCapacity)
+}