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.
5 #ifndef WEBKIT_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_
6 #define WEBKIT_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_
10 #include "webkit/common/blob/scoped_file.h"
12 namespace webkit_blob {
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
18 class WEBKIT_STORAGE_COMMON_EXPORT ShareableFileReference
19 : public base::RefCounted<ShareableFileReference> {
21 typedef ScopedFile::ScopeOutCallback FinalReleaseCallback;
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,
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);
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);
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.
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);
53 // The full file path.
54 const base::FilePath& path() const { return scoped_file_.path(); }
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);
62 friend class base::RefCounted<ShareableFileReference>;
64 ShareableFileReference(ScopedFile scoped_file);
65 ~ShareableFileReference();
67 ScopedFile scoped_file_;
69 DISALLOW_COPY_AND_ASSIGN(ShareableFileReference);
72 } // namespace webkit_blob
74 #endif // WEBKIT_COMMON_BLOB_SHAREABLE_FILE_REFERENCE_H_