update config format

etc/ledis.json

@@ -1,10 +1,12 @@
 {
     "addr": "127.0.0.1:6380",
-    "leveldb": {
-        "path": "/tmp/ledisdb",
-        "compression": false,
-        "block_size": 32768,
-        "write_buffer_size": 67108864,
-        "cache_size": 524288000
+    "db": {
+        "data_db" : {
+            "path": "/tmp/ledisdb",
+            "compression": false,
+            "block_size": 32768,
+            "write_buffer_size": 67108864,
+            "cache_size": 524288000            
+        }
     }
 }

ledis/app_test.go

@@ -45,13 +45,14 @@ func startTestApp() {
 		var d = []byte(`
             {
                 "addr" : "127.0.0.1:16380",
-                "leveldb" :     
-                {
-                    "path" : "/tmp/testdb",
-                    "compression":true,
-                    "block_size" : 32768,
-                    "write_buffer_size" : 2097152,
-                    "cache_size" : 20971520
+                "db" : {
+                    "data_db" : {
+                        "path" : "/tmp/testdb",
+                        "compression":true,
+                        "block_size" : 32768,
+                        "write_buffer_size" : 2097152,
+                        "cache_size" : 20971520
+                    }
                 }    
             }
             `)

ledis/config.go

@@ -2,14 +2,13 @@ package ledis
 
 import (
 	"encoding/json"
-	"github.com/siddontang/go-leveldb/leveldb"
 	"io/ioutil"
 )
 
 type Config struct {
 	Addr string `json:"addr"`
 
-	DB leveldb.Config `json:"leveldb"`
+	DB DBConfig `json:"db"`
 }
 
 func NewConfig(data json.RawMessage) (*Config, error) {

ledis/db.go

@@ -5,7 +5,13 @@ import (
 	"github.com/siddontang/go-leveldb/leveldb"
 )
 
+type DBConfig struct {
+	DataDB leveldb.Config `json:"data_db"`
+}
+
 type DB struct {
+	cfg *DBConfig
+
 	db *leveldb.DB
 
 	kvTx   *tx
@@ -15,26 +21,25 @@ type DB struct {
 }
 
 func OpenDB(configJson json.RawMessage) (*DB, error) {
-	db, err := leveldb.Open(configJson)
+	var cfg DBConfig
+
+	if err := json.Unmarshal(configJson, &cfg); err != nil {
+		return nil, err
+	}
+
+	return OpenDBWithConfig(&cfg)
+}
+
+func OpenDBWithConfig(cfg *DBConfig) (*DB, error) {
+	db, err := leveldb.OpenWithConfig(&cfg.DataDB)
 	if err != nil {
 		return nil, err
 	}
 
-	return newDB(db)
-}
-
-func OpenDBWithConfig(cfg *leveldb.Config) (*DB, error) {
-	db, err := leveldb.OpenWithConfig(cfg)
-	if err != nil {
-		return nil, err
-	}
-
-	return newDB(db)
-}
-
-func newDB(db *leveldb.DB) (*DB, error) {
 	d := new(DB)
 
+	d.cfg = cfg
+
 	d.db = db
 
 	d.kvTx = &tx{wb: db.NewWriteBatch()}