// 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_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_ #define WEBKIT_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_ #include <vector> #include "webkit/common/blob/scoped_file.h" namespace webkit_blob { // ShareableFileReference allows consumers to share FileReference for the // same path if it already exists in its internal map. // This class is non-thread-safe and all methods must be called on a single // thread. class WEBKIT_STORAGE_COMMON_EXPORT ShareableFileReference : public base::RefCounted<ShareableFileReference> { public: typedef ScopedFile::ScopeOutCallback FinalReleaseCallback; enum FinalReleasePolicy { DELETE_ON_FINAL_RELEASE = ScopedFile::DELETE_ON_SCOPE_OUT, DONT_DELETE_ON_FINAL_RELEASE = ScopedFile::DONT_DELETE_ON_SCOPE_OUT, }; // Returns a ShareableFileReference for the given path, if no reference // for this path exists returns NULL. static scoped_refptr<ShareableFileReference> Get(const base::FilePath& path); // Returns a ShareableFileReference for the given path, creating a new // reference if none yet exists. If there's a pre-existing reference for // the path, the policy parameter of this method is ignored. static scoped_refptr<ShareableFileReference> GetOrCreate( const base::FilePath& path, FinalReleasePolicy policy, base::TaskRunner* file_task_runner); // Returns a ShareableFileReference for the given path of the |scoped_file|, // creating a new reference if none yet exists. The ownership of |scoped_file| // is passed to this reference. // If there's a pre-existing reference for the path, the scope out policy // and scope-out-callbacks of the given |scoped_file| is ignored. // If the given scoped_file has an empty path (e.g. maybe already // released) this returns NULL reference. // // TODO(kinuko): Make sure if this behavior is ok, we could alternatively // merge callbacks to the existing one. static scoped_refptr<ShareableFileReference> GetOrCreate( ScopedFile scoped_file); // The full file path. const base::FilePath& path() const { return scoped_file_.path(); } // The |callback| is fired when the final reference of this instance // is released. If release policy is DELETE_ON_FINAL_RELEASE the // callback task(s) is/are posted before the deletion is scheduled. void AddFinalReleaseCallback(const FinalReleaseCallback& callback); private: friend class base::RefCounted<ShareableFileReference>; ShareableFileReference(ScopedFile scoped_file); ~ShareableFileReference(); ScopedFile scoped_file_; DISALLOW_COPY_AND_ASSIGN(ShareableFileReference); }; } // namespace webkit_blob #endif // WEBKIT_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_