1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef STORAGE_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_ 6 #define STORAGE_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_ 7 8 #include <vector> 9 10 #include "storage/common/blob/scoped_file.h" 11 12 namespace storage { 13 14 // ShareableFileReference allows consumers to share FileReference for the 15 // same path if it already exists in its internal map. 16 // This class is non-thread-safe and all methods must be called on a single 17 // thread. 18 class STORAGE_COMMON_EXPORT ShareableFileReference 19 : public base::RefCounted<ShareableFileReference> { 20 public: 21 typedef ScopedFile::ScopeOutCallback FinalReleaseCallback; 22 23 enum FinalReleasePolicy { 24 DELETE_ON_FINAL_RELEASE = ScopedFile::DELETE_ON_SCOPE_OUT, 25 DONT_DELETE_ON_FINAL_RELEASE = ScopedFile::DONT_DELETE_ON_SCOPE_OUT, 26 }; 27 28 // Returns a ShareableFileReference for the given path, if no reference 29 // for this path exists returns NULL. 30 static scoped_refptr<ShareableFileReference> Get(const base::FilePath& path); 31 32 // Returns a ShareableFileReference for the given path, creating a new 33 // reference if none yet exists. If there's a pre-existing reference for 34 // the path, the policy parameter of this method is ignored. 35 static scoped_refptr<ShareableFileReference> GetOrCreate( 36 const base::FilePath& path, 37 FinalReleasePolicy policy, 38 base::TaskRunner* file_task_runner); 39 40 // Returns a ShareableFileReference for the given path of the |scoped_file|, 41 // creating a new reference if none yet exists. The ownership of |scoped_file| 42 // is passed to this reference. 43 // If there's a pre-existing reference for the path, the scope out policy 44 // and scope-out-callbacks of the given |scoped_file| is ignored. 45 // If the given scoped_file has an empty path (e.g. maybe already 46 // released) this returns NULL reference. 47 // 48 // TODO(kinuko): Make sure if this behavior is ok, we could alternatively 49 // merge callbacks to the existing one. 50 static scoped_refptr<ShareableFileReference> GetOrCreate( 51 ScopedFile scoped_file); 52 53 // The full file path. 54 const base::FilePath& path() const { return scoped_file_.path(); } 55 56 // The |callback| is fired when the final reference of this instance 57 // is released. If release policy is DELETE_ON_FINAL_RELEASE the 58 // callback task(s) is/are posted before the deletion is scheduled. 59 void AddFinalReleaseCallback(const FinalReleaseCallback& callback); 60 61 private: 62 friend class base::RefCounted<ShareableFileReference>; 63 64 ShareableFileReference(ScopedFile scoped_file); 65 ~ShareableFileReference(); 66 67 ScopedFile scoped_file_; 68 69 DISALLOW_COPY_AND_ASSIGN(ShareableFileReference); 70 }; 71 72 } // namespace storage 73 74 #endif // STORAGE_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_ 75
