1 // Copyright (c) 2013 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 WEBKIT_COMMON_BLOB_SCOPED_FILE_H_ 6 #define WEBKIT_COMMON_BLOB_SCOPED_FILE_H_ 7 8 #include <map> 9 10 #include "base/callback_forward.h" 11 #include "base/files/file_path.h" 12 #include "base/memory/ref_counted.h" 13 #include "base/move.h" 14 #include "webkit/common/webkit_storage_common_export.h" 15 16 namespace base { 17 class TaskRunner; 18 } 19 20 namespace webkit_blob { 21 22 // A scoped reference for a FilePath that can optionally schedule the file 23 // to be deleted and/or to notify a consumer when it is going to be scoped out. 24 // This class supports move semantics, i.e. consumers can call Pass() to 25 // pass the ownership of ScopedFile. 26 // 27 // TODO(kinuko): Probably this can be moved under base or somewhere more 28 // common place. 29 class WEBKIT_STORAGE_COMMON_EXPORT ScopedFile { 30 // To support destructive assignment from an l-value assignment. 31 // This provides Pass() method which creates an r-value for the current 32 // instance. (See base/move.h for details) 33 MOVE_ONLY_TYPE_FOR_CPP_03(ScopedFile, RValue) 34 35 public: 36 typedef base::Callback<void(const base::FilePath&)> ScopeOutCallback; 37 typedef std::pair<ScopeOutCallback, scoped_refptr<base::TaskRunner> > 38 ScopeOutCallbackPair; 39 typedef std::vector<ScopeOutCallbackPair> ScopeOutCallbackList; 40 41 enum ScopeOutPolicy { 42 DELETE_ON_SCOPE_OUT, 43 DONT_DELETE_ON_SCOPE_OUT, 44 }; 45 46 ScopedFile(); 47 48 // |file_task_runner| is used to schedule a file deletion if |policy| 49 // is DELETE_ON_SCOPE_OUT. 50 ScopedFile(const base::FilePath& path, 51 ScopeOutPolicy policy, 52 base::TaskRunner* file_task_runner); 53 54 // Move constructor and operator. The data of r-value will be transfered 55 // in a destructive way. (See base/move.h) 56 ScopedFile(RValue other); 57 ScopedFile& operator=(RValue rhs) { 58 MoveFrom(*rhs.object); 59 return *this; 60 } 61 62 ~ScopedFile(); 63 64 // The |callback| is fired on |callback_runner| when the final reference 65 // of this instance is released. 66 // If release policy is DELETE_ON_SCOPE_OUT the 67 // callback task(s) is/are posted before the deletion is scheduled. 68 void AddScopeOutCallback(const ScopeOutCallback& callback, 69 base::TaskRunner* callback_runner); 70 71 // The full file path. path()72 const base::FilePath& path() const { return path_; } 73 74 // Releases the file. After calling this, this instance will hold 75 // an empty file path and scoping out won't make any file deletion 76 // or callback dispatch. (If an owned pointer is attached to any of 77 // callbacks the pointer will be deleted.) 78 base::FilePath Release(); 79 80 void Reset(); 81 82 private: 83 // Performs destructive move from |other| to this. 84 void MoveFrom(ScopedFile& other); 85 86 base::FilePath path_; 87 ScopeOutPolicy scope_out_policy_; 88 scoped_refptr<base::TaskRunner> file_task_runner_; 89 ScopeOutCallbackList scope_out_callbacks_; 90 }; 91 92 } // namespace webkit_blob 93 94 #endif // WEBKIT_COMMON_BLOB_SCOPED_FILE_H_ 95