From 4864c567f709f8fe64065d6e49b81147985f416c Mon Sep 17 00:00:00 2001
From: yangsen <yang_sen_ysys@163.com>
Date: Tue, 2 Mar 2021 18:36:10 +0800
Subject: [PATCH] create city by byte array

---
 city.go   | 12 ++++++++++++
 reader.go | 12 +++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/city.go b/city.go
index 9ce0ca4..d97e96b 100644
--- a/city.go
+++ b/city.go
@@ -71,6 +71,18 @@ func NewCity(name string) (*City, error) {
 	}, nil
 }
 
+func NewCityWithData(data []byte) (*City, error) {
+
+	r, e := newReaderWithData(data, &CityInfo{})
+	if e != nil {
+		return nil, e
+	}
+
+	return &City{
+		reader: r,
+	}, nil
+}
+
 // Reload the database
 func (db *City) Reload(name string) error {
 
diff --git a/reader.go b/reader.go
index d4838d7..949a97a 100644
--- a/reader.go
+++ b/reader.go
@@ -67,12 +67,18 @@ func newReader(name string, obj interface{}) (*reader, error) {
 	if err != nil {
 		return nil, ErrReadFull
 	}
+	return newReaderWithData(body, obj)
+}
+
+func newReaderWithData(data []byte, obj interface{}) (*reader, error) {
+
+	fileSize := len(data)
 	var meta MetaData
-	metaLength := int(binary.BigEndian.Uint32(body[0:4]))
+	metaLength := int(binary.BigEndian.Uint32(data[0:4]))
 	if fileSize < (4 + metaLength) {
 		return nil, ErrFileSize
 	}
-	if err := json.Unmarshal(body[4:4+metaLength], &meta); err != nil {
+	if err := json.Unmarshal(data[4:4+metaLength], &meta); err != nil {
 		return nil, err
 	}
 	if len(meta.Languages) == 0 || len(meta.Fields) == 0 {
@@ -99,7 +105,7 @@ func newReader(name string, obj interface{}) (*reader, error) {
 		meta:    meta,
 		refType: dm,
 
-		data: body[4+metaLength:],
+		data: data[4+metaLength:],
 	}
 
 	if db.v4offset == 0 {