diff --git a/leveldb/db.go b/leveldb/db.go
index 0148b61..c6bfa94 100644
--- a/leveldb/db.go
+++ b/leveldb/db.go
@@ -289,14 +289,16 @@ func (db *DB) RevRangeIterator(min []byte, max []byte, rangeType uint8) *RangeLi
 	return NewRevRangeLimitIterator(db.NewIterator(), &Range{min, max, rangeType}, &Limit{0, -1})
 }
 
-//count < 0, unlimit
-//offset must >= 0, if < 0, will get nothing
+//count < 0, unlimit.
+//
+//offset must >= 0, if < 0, will get nothing.
 func (db *DB) RangeLimitIterator(min []byte, max []byte, rangeType uint8, offset int, count int) *RangeLimitIterator {
 	return NewRangeLimitIterator(db.NewIterator(), &Range{min, max, rangeType}, &Limit{offset, count})
 }
 
-//count < 0, unlimit
-//offset must >= 0, if < 0, will get nothing
+//count < 0, unlimit.
+//
+//offset must >= 0, if < 0, will get nothing.
 func (db *DB) RevRangeLimitIterator(min []byte, max []byte, rangeType uint8, offset int, count int) *RangeLimitIterator {
 	return NewRevRangeLimitIterator(db.NewIterator(), &Range{min, max, rangeType}, &Limit{offset, count})
 }
diff --git a/leveldb/iterator.go b/leveldb/iterator.go
index 6092e9d..3c3e811 100644
--- a/leveldb/iterator.go
+++ b/leveldb/iterator.go
@@ -24,11 +24,14 @@ const (
 )
 
 // min must less or equal than max
+//
 // range type:
-// close: [min, max]
-// open: (min, max)
-// lopen: (min, max]
-// ropen: [min, max)
+//
+// 	close: [min, max]
+// 	open: (min, max)
+// 	lopen: (min, max]
+// 	ropen: [min, max)
+//
 type Range struct {
 	Min []byte
 	Max []byte
@@ -92,7 +95,7 @@ func (it *Iterator) RawValue() []byte {
 	return slice(unsafe.Pointer(vdata), int(C.int(vlen)))
 }
 
-// Copy key to b, if b len is small or nil, returns a new one
+// Copy key to b, if b len is small or nil, returns a new one.
 func (it *Iterator) BufKey(b []byte) []byte {
 	k := it.RawKey()
 	if k == nil {
@@ -106,7 +109,7 @@ func (it *Iterator) BufKey(b []byte) []byte {
 	return append(b, k...)
 }
 
-// Copy value to b, if b len is small or nil, returns a new one
+// Copy value to b, if b len is small or nil, returns a new one.
 func (it *Iterator) BufValue(b []byte) []byte {
 	v := it.RawValue()
 	if v == nil {
@@ -150,7 +153,7 @@ func (it *Iterator) Seek(key []byte) {
 	it.isValid = C.leveldb_iter_seek_ext(it.it, (*C.char)(unsafe.Pointer(&key[0])), C.size_t(len(key)))
 }
 
-// Finds by key, if not found, nil returns
+// Finds by key, if not found, nil returns.
 func (it *Iterator) Find(key []byte) []byte {
 	it.Seek(key)
 	if it.Valid() {
@@ -165,7 +168,7 @@ func (it *Iterator) Find(key []byte) []byte {
 	return nil
 }
 
-// Finds by key, if not found, nil returns, else a reference of value returns
+// Finds by key, if not found, nil returns, else a reference of value returns.
 // you must be careful that it will be changed after next iterate.
 func (it *Iterator) RawFind(key []byte) []byte {
 	it.Seek(key)
diff --git a/leveldb/options.go b/leveldb/options.go
index f080c24..62836c0 100644
--- a/leveldb/options.go
+++ b/leveldb/options.go
@@ -55,14 +55,6 @@ func (o *Options) SetCache(cache *Cache) {
 	C.leveldb_options_set_cache(o.Opt, cache.Cache)
 }
 
-// func (o *Options) SetEnv(env *Env) {
-// 	C.leveldb_options_set_env(o.Opt, env.Env)
-// }
-
-func (o *Options) SetInfoLog(log *C.leveldb_logger_t) {
-	C.leveldb_options_set_info_log(o.Opt, log)
-}
-
 func (o *Options) SetWriteBufferSize(s int) {
 	C.leveldb_options_set_write_buffer_size(o.Opt, C.size_t(s))
 }
diff --git a/leveldb/snapshot.go b/leveldb/snapshot.go
index 82c7363..7d49317 100644
--- a/leveldb/snapshot.go
+++ b/leveldb/snapshot.go
@@ -45,14 +45,16 @@ func (s *Snapshot) RevRangeIterator(min []byte, max []byte, rangeType uint8) *Ra
 	return NewRevRangeLimitIterator(s.NewIterator(), &Range{min, max, rangeType}, &Limit{0, -1})
 }
 
-//count < 0, unlimit
-//offset must >= 0, if < 0, will get nothing
+//count < 0, unlimit.
+//
+//offset must >= 0, if < 0, will get nothing.
 func (s *Snapshot) RangeLimitIterator(min []byte, max []byte, rangeType uint8, offset int, count int) *RangeLimitIterator {
 	return NewRangeLimitIterator(s.NewIterator(), &Range{min, max, rangeType}, &Limit{offset, count})
 }
 
-//count < 0, unlimit
-//offset must >= 0, if < 0, will get nothing
+//count < 0, unlimit.
+//
+//offset must >= 0, if < 0, will get nothing.
 func (s *Snapshot) RevRangeLimitIterator(min []byte, max []byte, rangeType uint8, offset int, count int) *RangeLimitIterator {
 	return NewRevRangeLimitIterator(s.NewIterator(), &Range{min, max, rangeType}, &Limit{offset, count})
 }