Refactor FileSystem

webkit/plugins/ppapi/ppb_file_ref_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WEBKIT_PLUGINS_PPAPI_PPB_FILE_REF_IMPL_H_
 #define WEBKIT_PLUGINS_PPAPI_PPB_FILE_REF_IMPL_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
 #include "googleurl/src/gurl.h"
 #include "ppapi/c/pp_file_info.h"
 #include "ppapi/c/ppb_file_ref.h"
 #include "ppapi/shared_impl/ppb_file_ref_shared.h"
+#include "ppapi/shared_impl/scoped_pp_resource.h"
 #include "ppapi/shared_impl/var.h"
 #include "webkit/glue/webkit_glue_export.h"
 
 namespace webkit {
 namespace ppapi {
 
 using ::ppapi::StringVar;
 
 class PPB_FileSystem_Impl;
 
 class WEBKIT_GLUE_EXPORT PPB_FileRef_Impl
     : public ::ppapi::PPB_FileRef_Shared {
  public:
   PPB_FileRef_Impl(const ::ppapi::PPB_FileRef_CreateInfo& info,
-                   PPB_FileSystem_Impl* file_system);
+                   PP_Resource file_system);
   PPB_FileRef_Impl(const ::ppapi::PPB_FileRef_CreateInfo& info,
                    const base::FilePath& external_file_path);
   virtual ~PPB_FileRef_Impl();
 
   // The returned object will have a refcount of 0 (just like "new").
-  static PPB_FileRef_Impl* CreateInternal(PP_Resource pp_file_system,
+  static PPB_FileRef_Impl* CreateInternal(PP_Instance instance,
+                                          PP_Resource pp_file_system,
                                           const std::string& path);
 
   // The returned object will have a refcount of 0 (just like "new").
-  static PPB_FileRef_Impl* CreateExternal(PP_Instance instance,
-                                          const base::FilePath& external_file_path,
-                                          const std::string& display_name);
+  static PPB_FileRef_Impl* CreateExternal(
+      PP_Instance instance,
+      const base::FilePath& external_file_path,
+      const std::string& display_name);
 
   // PPB_FileRef_API implementation (not provided by PPB_FileRef_Shared).
   virtual PP_Resource GetParent() OVERRIDE;
   virtual int32_t MakeDirectory(
       PP_Bool make_ancestors,
       scoped_refptr< ::ppapi::TrackedCallback> callback) OVERRIDE;
   virtual int32_t Touch(
       PP_Time last_access_time,
       PP_Time last_modified_time,
       scoped_refptr< ::ppapi::TrackedCallback> callback) OVERRIDE;
   virtual int32_t Delete(
       scoped_refptr< ::ppapi::TrackedCallback> callback) OVERRIDE;
   virtual int32_t Rename(
       PP_Resource new_file_ref,
       scoped_refptr< ::ppapi::TrackedCallback> callback) OVERRIDE;
   virtual int32_t Query(
       PP_FileInfo* info,
       scoped_refptr< ::ppapi::TrackedCallback> callback) OVERRIDE;
   virtual PP_Var GetAbsolutePath();
 
-  PPB_FileSystem_Impl* file_system() const { return file_system_.get(); }
+  PP_Resource file_system_resource() const { return file_system_; }
 
   // Returns the system path corresponding to this file. Valid only for
   // external filesystems.
   base::FilePath GetSystemPath() const;
 
   // Returns the FileSystem API URL corresponding to this file.
   GURL GetFileSystemURL() const;
 
   // Checks if file ref has file system instance and if the instance is opened.
   bool HasValidFileSystem() const;
+
+  void AddFileSystemRefCount() {
+    file_system_ref_ = file_system_;
+  }
+
  private:
   // Many mutation functions are allow only to non-external filesystems, This
   // function returns true if the filesystem is opened and isn't external as an
   // access check for these functions.
   bool IsValidNonExternalFileSystem() const;
 
-  // Null for external filesystems.
-  scoped_refptr<PPB_FileSystem_Impl> file_system_;
+  // 0 for external filesystems.  This is a plugin side resource that we don't
+  // hold a reference here, so file_system_ could be destroyed earlier than
+  // this object.  Right now we checked the existance in plugin delegate before
+  // use.  But it's better to hold a reference once we migrate FileRef to the
+  // new design.
+  PP_Resource file_system_;
+
+  // Holds a reference of FileSystem when running in process.  See
+  // PPB_FileRef_Proxy for corresponding code for out-of-process mode.  Note
+  // that this ScopedPPResource is only expected to be used when running in
+  // process (since PPB_FileRef_Proxy takes care of out-of-process case).
+  // Also note that this workaround will be no longer needed after FileRef
+  // refactoring.
+  ::ppapi::ScopedPPResource file_system_ref_;
 
   // Used only for external filesystems.
   base::FilePath external_file_system_path_;
 
   // Lazily initialized var created from the external path. This is so we can
   // return the identical string object every time it is requested.
   scoped_refptr<StringVar> external_path_var_;
 
   DISALLOW_COPY_AND_ASSIGN(PPB_FileRef_Impl);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPB_FILE_REF_IMPL_H_