// Copyright (c) 2013 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_COMMON_BLOB_SCOPED_FILE_H_ #define WEBKIT_COMMON_BLOB_SCOPED_FILE_H_ #include <map> #include "base/callback_forward.h" #include "base/files/file_path.h" #include "base/memory/ref_counted.h" #include "base/move.h" #include "webkit/common/webkit_storage_common_export.h" namespace base { class TaskRunner; } namespace webkit_blob { // A scoped reference for a FilePath that can optionally schedule the file // to be deleted and/or to notify a consumer when it is going to be scoped out. // This class supports move semantics, i.e. consumers can call Pass() to // pass the ownership of ScopedFile. // // TODO(kinuko): Probably this can be moved under base or somewhere more // common place. class WEBKIT_STORAGE_COMMON_EXPORT ScopedFile { // To support destructive assignment from an l-value assignment. // This provides Pass() method which creates an r-value for the current // instance. (See base/move.h for details) MOVE_ONLY_TYPE_FOR_CPP_03(ScopedFile, RValue) public: typedef base::Callback<void(const base::FilePath&)> ScopeOutCallback; typedef std::pair<ScopeOutCallback, scoped_refptr<base::TaskRunner> > ScopeOutCallbackPair; typedef std::vector<ScopeOutCallbackPair> ScopeOutCallbackList; enum ScopeOutPolicy { DELETE_ON_SCOPE_OUT, DONT_DELETE_ON_SCOPE_OUT, }; ScopedFile(); // |file_task_runner| is used to schedule a file deletion if |policy| // is DELETE_ON_SCOPE_OUT. ScopedFile(const base::FilePath& path, ScopeOutPolicy policy, base::TaskRunner* file_task_runner); // Move constructor and operator. The data of r-value will be transfered // in a destructive way. (See base/move.h) ScopedFile(RValue other); ScopedFile& operator=(RValue rhs) { MoveFrom(*rhs.object); return *this; } ~ScopedFile(); // The |callback| is fired on |callback_runner| when the final reference // of this instance is released. // If release policy is DELETE_ON_SCOPE_OUT the // callback task(s) is/are posted before the deletion is scheduled. void AddScopeOutCallback(const ScopeOutCallback& callback, base::TaskRunner* callback_runner); // The full file path. const base::FilePath& path() const { return path_; } // Releases the file. After calling this, this instance will hold // an empty file path and scoping out won't make any file deletion // or callback dispatch. (If an owned pointer is attached to any of // callbacks the pointer will be deleted.) base::FilePath Release(); void Reset(); private: // Performs destructive move from |other| to this. void MoveFrom(ScopedFile& other); base::FilePath path_; ScopeOutPolicy scope_out_policy_; scoped_refptr<base::TaskRunner> file_task_runner_; ScopeOutCallbackList scope_out_callbacks_; }; } // namespace webkit_blob #endif // WEBKIT_COMMON_BLOB_SCOPED_FILE_H_