optimize BufGet

leveldb/db.go

@@ -345,13 +345,13 @@ func (db *DB) get(r []byte, ro *ReadOptions, key []byte) ([]byte, error) {
 
 	defer C.leveldb_get_free_ext(unsafe.Pointer(c))
 
-	if r == nil || int(C.int(vallen)) > len(r) {
-		return C.GoBytes(unsafe.Pointer(value), C.int(vallen)), nil
-	} else {
-		b := slice(unsafe.Pointer(value), int(C.int(vallen)))
-		n := copy(r, b)
-		return r[0:n], nil
+	if r == nil {
+		r = []byte{}
 	}
+
+	r = r[0:0]
+	b := slice(unsafe.Pointer(value), int(C.int(vallen)))
+	return append(r, b...), nil
 }
 
 func (db *DB) delete(wo *WriteOptions, key []byte) error {

leveldb/iterator.go

@@ -98,12 +98,12 @@ func (it *Iterator) BufKey(b []byte) []byte {
 	if k == nil {
 		return nil
 	}
-	if b == nil || len(k) > len(b) {
-		b = make([]byte, len(k))
+	if b == nil {
+		b = []byte{}
 	}
 
-	n := copy(b, k)
-	return b[0:n]
+	b = b[0:0]
+	return append(b, k...)
 }
 
 //Copy value to b, if b len is small or nil, returns a new one
@@ -112,12 +112,13 @@ func (it *Iterator) BufValue(b []byte) []byte {
 	if v == nil {
 		return nil
 	}
-	if b == nil || len(v) > len(b) {
-		b = make([]byte, len(v))
+
+	if b == nil {
+		b = []byte{}
 	}
 
-	n := copy(b, v)
-	return b[0:n]
+	b = b[0:0]
+	return append(b, v...)
 }
 
 func (it *Iterator) Close() {