Add leveldb to db backend and fix error wrapping

manager/db.go

@@ -9,6 +9,8 @@ import (
 	"github.com/boltdb/bolt"
 	"github.com/dgraph-io/badger/v2"
 	"github.com/go-redis/redis/v8"
+	"github.com/pkg/errors"
+	"github.com/syndtr/goleveldb/leveldb"
 
 	. "github.com/tuna/tunasync/internal"
 )
@@ -86,6 +88,19 @@ func makeDBAdapter(dbType string, dbFile string) (dbAdapter, error) {
 		}
 		err = kv.Init()
 		return &kv, err
+	} else if dbType == "leveldb" {
+		innerDB, err := leveldb.OpenFile(dbFile, nil)
+		if err != nil {
+			return nil, err
+		}
+		db := leveldbAdapter{
+			db: innerDB,
+		}
+		kv := kvDBAdapter{
+			db: &db,
+		}
+		err = kv.Init()
+		return &kv, err
 	}
 	// unsupported db-type
 	return nil, fmt.Errorf("unsupported db-type: %s", dbType)
@@ -116,7 +131,7 @@ func (b *kvDBAdapter) ListWorkers() (ws []WorkerStatus, err error) {
 	for _, v := range workers {
 		jsonErr := json.Unmarshal(v, &w)
 		if jsonErr != nil {
-			err = fmt.Errorf("%s; %s", err.Error(), jsonErr)
+			err = errors.Wrap(err, jsonErr.Error())
 			continue
 		}
 		ws = append(ws, w)
@@ -193,7 +208,7 @@ func (b *kvDBAdapter) ListMirrorStatus(workerID string) (ms []MirrorStatus, err
 			var m MirrorStatus
 			jsonErr := json.Unmarshal(v, &m)
 			if jsonErr != nil {
-				err = fmt.Errorf("%s; %s", err.Error(), jsonErr)
+				err = errors.Wrap(err, jsonErr.Error())
 				continue
 			}
 			ms = append(ms, m)
@@ -213,7 +228,7 @@ func (b *kvDBAdapter) ListAllMirrorStatus() (ms []MirrorStatus, err error) {
 		var m MirrorStatus
 		jsonErr := json.Unmarshal(v, &m)
 		if jsonErr != nil {
-			err = fmt.Errorf("%s; %s", err.Error(), jsonErr)
+			err = errors.Wrap(err, jsonErr.Error())
 			continue
 		}
 		ms = append(ms, m)
@@ -232,13 +247,13 @@ func (b *kvDBAdapter) FlushDisabledJobs() (err error) {
 		var m MirrorStatus
 		jsonErr := json.Unmarshal(v, &m)
 		if jsonErr != nil {
-			err = fmt.Errorf("%s; %s", err.Error(), jsonErr)
+			err = errors.Wrap(err, jsonErr.Error())
 			continue
 		}
 		if m.Status == Disabled || len(m.Name) == 0 {
 			deleteErr := b.db.Delete(_statusBucketKey, k)
 			if deleteErr != nil {
-				err = fmt.Errorf("%s; %s", err.Error(), deleteErr)
+				err = errors.Wrap(err, deleteErr.Error())
 			}
 		}
 	}

manager/db_leveldb.go

@@ -0,0 +1,51 @@
+package manager
+
+import (
+	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/syndtr/goleveldb/leveldb/util"
+)
+
+// implement kv interface backed by leveldb
+type leveldbAdapter struct {
+	db *leveldb.DB
+}
+
+func (b *leveldbAdapter) InitBucket(bucket string) (err error) {
+	// no-op
+	return
+}
+
+func (b *leveldbAdapter) Get(bucket string, key string) (v []byte, err error) {
+	v, err = b.db.Get([]byte(bucket+key), nil)
+	return
+}
+
+func (b *leveldbAdapter) GetAll(bucket string) (m map[string][]byte, err error) {
+	it := b.db.NewIterator(util.BytesPrefix([]byte(bucket)), nil)
+	defer it.Release()
+	m = make(map[string][]byte)
+	for it.Next() {
+		k := string(it.Key())
+		actualKey := k[len(bucket):]
+		// it.Value() changes on next iteration
+		val := it.Value()
+		v := make([]byte, len(val))
+		copy(v, it.Value())
+		m[actualKey] = v
+	}
+	return
+}
+
+func (b *leveldbAdapter) Put(bucket string, key string, value []byte) error {
+	err := b.db.Put([]byte(bucket+key), []byte(value), nil)
+	return err
+}
+
+func (b *leveldbAdapter) Delete(bucket string, key string) error {
+	err := b.db.Delete([]byte(bucket+key), nil)
+	return err
+}
+
+func (b *leveldbAdapter) Close() error {
+	return b.db.Close()
+}

manager/db_test.go

@@ -216,4 +216,22 @@ func TestDBAdapter(t *testing.T) {
 
 		DBAdapterTest(badgerDB)
 	})
+
+	Convey("leveldbAdapter should work", t, func() {
+		tmpDir, err := ioutil.TempDir("", "tunasync")
+		defer os.RemoveAll(tmpDir)
+		So(err, ShouldBeNil)
+
+		dbType, dbFile := "leveldb", filepath.Join(tmpDir, "leveldb.db")
+		leveldbDB, err := makeDBAdapter(dbType, dbFile)
+		So(err, ShouldBeNil)
+
+		defer func() {
+			// close leveldbDB
+			err := leveldbDB.Close()
+			So(err, ShouldBeNil)
+		}()
+
+		DBAdapterTest(leveldbDB)
+	})
 }