fix: close upon batch write erroro

chore: removed duplicated line, added comments about read / write options

rdb/batch.go

@@ -55,10 +55,10 @@ func (b *rdbBatch) Write() error {
 	}
 	var cerr *C.char
 	C.rocksdb_write(b.db.db, b.db.wopts, b.b, &cerr)
+	b.Close()
 	if cerr != nil {
 		return cerror(cerr)
 	}
-	b.Close()
 	return nil
 }
 
@@ -68,10 +68,10 @@ func (b *rdbBatch) WriteSync() error {
 	}
 	var cerr *C.char
 	C.rocksdb_write(b.db.db, b.db.wsopts, b.b, &cerr)
+	b.Close()
 	if cerr != nil {
 		return cerror(cerr)
 	}
-	b.Close()
 	return nil
 }
 
@@ -81,10 +81,10 @@ func (b *rdbBatch) WriteLowPri() error {
 	}
 	var cerr *C.char
 	C.rocksdb_write(b.db.db, b.db.wlpopts, b.b, &cerr)
+	b.Close()
 	if cerr != nil {
 		return cerror(cerr)
 	}
-	b.Close()
 	return nil
 }
 

rdb/db.go

@@ -19,14 +19,14 @@ import (
 )
 
 type RDB struct {
-	name   string
-	fn     string
-	db     *C.rocksdb_t
-	opts   *C.rocksdb_options_t
-	ropts  *C.rocksdb_readoptions_t
-	wopts  *C.rocksdb_writeoptions_t
-	wsopts *C.rocksdb_writeoptions_t
-	wlpopts *C.rocksdb_writeoptions_t
+	name    string
+	fn      string
+	db      *C.rocksdb_t
+	opts    *C.rocksdb_options_t
+	ropts   *C.rocksdb_readoptions_t  // read options
+	wopts   *C.rocksdb_writeoptions_t // write options
+	wsopts  *C.rocksdb_writeoptions_t // sync write options
+	wlpopts *C.rocksdb_writeoptions_t // low priority write options
 }
 
 type rdbIterator struct {
@@ -69,7 +69,6 @@ func NewDB(name string, dir string) (*RDB, error) {
 	C.rocksdb_options_set_create_if_missing(opts, 1)
 	C.rocksdb_options_increase_parallelism(opts, C.int(runtime.NumCPU()))
 	C.rocksdb_options_optimize_level_style_compaction(opts, 512*1024*1024)
-	C.rocksdb_options_optimize_level_style_compaction(opts, 512*1024*1024)
 	C.rocksdb_options_set_enable_pipelined_write(opts, 1)
 
 	ropts := C.rocksdb_readoptions_create()
@@ -88,13 +87,13 @@ func NewDB(name string, dir string) (*RDB, error) {
 		return nil, cerror(cerr)
 	}
 	return &RDB{
-		name:   name,
-		fn:     fn,
-		db:     db,
-		opts:   opts,
-		ropts:  ropts,
-		wopts:  wopts,
-		wsopts: wsopts,
+		name:    name,
+		fn:      fn,
+		db:      db,
+		opts:    opts,
+		ropts:   ropts,
+		wopts:   wopts,
+		wsopts:  wsopts,
 		wlpopts: wlpopts,
 	}, nil
 }
@@ -109,8 +108,7 @@ func (db *RDB) Get(key []byte) ([]byte, error) {
 	ck := b2c(key)
 	cv := C.rocksdb_get(db.db, db.ropts, ck, C.size_t(len(key)), &cvl, &cerr)
 	if cerr != nil {
-		err := cerror(cerr)
-		return nil, err
+		return nil, cerror(cerr)
 	}
 	if cv == nil {
 		return nil, nil