添加获取热存储对象的方法

bot.go

@@ -1,7 +1,6 @@
 package openwechat
 
 import (
-	"bytes"
     "context"
     "encoding/json"
     "errors"
@@ -67,19 +66,15 @@ func (b *Bot) HotLogin(storage HotReloadStorage, retry ...bool) error {
 
     // 如果load出错了,就执行正常登陆逻辑
     // 第一次没有数据load都会出错的
-	var buffer bytes.Buffer
-	if _, err := buffer.ReadFrom(storage); err != nil {
+    item, err := NewHotReloadStorageItem(storage)
+
+    if err != nil {
         return b.Login()
     }
-	defer b.HotReloadStorage.Close()
 
-	var item HotReloadStorageItem
+    defer storage.Close()
 
-	if err = json.NewDecoder(&buffer).Decode(&item); err != nil {
-		return err
-	}
-
-	if err = b.hotLoginInit(item); err != nil {
+    if err = b.hotLoginInit(*item); err != nil {
         return err
     }
 

stroage.go

@@ -1,6 +1,9 @@
 package openwechat
 
 import (
+    "bytes"
+    "encoding/json"
+    "errors"
     "io"
     "net/http"
     "os"
@@ -60,3 +63,19 @@ func NewJsonFileHotReloadStorage(filename string) HotReloadStorage {
 }
 
 var _ HotReloadStorage = &JsonFileHotReloadStorage{}
+
+func NewHotReloadStorageItem(storage HotReloadStorage) (*HotReloadStorageItem, error) {
+    if storage == nil {
+        return nil, errors.New("storage can't be nil")
+    }
+    var buffer bytes.Buffer
+    if _, err := buffer.ReadFrom(storage); err != nil {
+        return nil, err
+    }
+    var item HotReloadStorageItem
+
+    if err := json.NewDecoder(&buffer).Decode(&item); err != nil {
+        return nil, err
+    }
+    return &item, nil
+}