1// Copyright 2014 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 CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_ACTIVE_BLOB_REGISTRY_H_
6#define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_ACTIVE_BLOB_REGISTRY_H_
7
8#include <map>
9#include <set>
10#include <utility>
11#include "base/basictypes.h"
12#include "base/files/file_path.h"
13#include "base/memory/weak_ptr.h"
14#include "content/common/content_export.h"
15#include "storage/common/blob/shareable_file_reference.h"
16
17namespace content {
18
19class IndexedDBBackingStore;
20
21class CONTENT_EXPORT IndexedDBActiveBlobRegistry {
22 public:
23  explicit IndexedDBActiveBlobRegistry(IndexedDBBackingStore* backing_store);
24  ~IndexedDBActiveBlobRegistry();
25
26  // Most methods of this class, and the closure returned by
27  // GetAddBlobRefCallback, should only be called on the backing_store's task
28  // runner.  The exception is the closure returned by GetFinalReleaseCallback,
29  // which just calls ReleaseBlobRefThreadSafe.
30
31  // Use DatabaseMetaDataKey::AllBlobsKey for "the whole database".
32  bool MarkDeletedCheckIfUsed(int64 database_id, int64 blob_key);
33
34  storage::ShareableFileReference::FinalReleaseCallback GetFinalReleaseCallback(
35      int64 database_id,
36      int64 blob_key);
37  // This closure holds a raw pointer to the IndexedDBActiveBlobRegistry,
38  // and may not be called after it is deleted.
39  base::Closure GetAddBlobRefCallback(int64 database_id, int64 blob_key);
40  // Call this to force the registry to drop its use counts, permitting the
41  // factory to drop any blob-related refcount for the backing store.
42  // This will also turn any outstanding callbacks into no-ops.
43  void ForceShutdown();
44
45 private:
46  // Maps blob_key -> IsDeleted; if the record's absent, it's not in active use
47  // and we don't care if it's deleted.
48  typedef std::map<int64, bool> SingleDBMap;
49  // Maps DB ID -> SingleDBMap
50  typedef std::map<int64, SingleDBMap> AllDBsMap;
51  typedef std::set<int64> DeletedDBSet;
52
53  void AddBlobRef(int64 database_id, int64 blob_key);
54  void ReleaseBlobRef(int64 database_id, int64 blob_key);
55  static void ReleaseBlobRefThreadSafe(
56      scoped_refptr<base::TaskRunner> task_runner,
57      base::WeakPtr<IndexedDBActiveBlobRegistry> weak_ptr,
58      int64 database_id,
59      int64 blob_key,
60      const base::FilePath& unused);
61
62  AllDBsMap use_tracker_;
63  DeletedDBSet deleted_dbs_;
64  // As long as we've got blobs registered in use_tracker_,
65  // backing_store_->factory() will keep backing_store_ alive for us.  And
66  // backing_store_ owns us, so we'll stay alive as long as we're needed.
67  IndexedDBBackingStore* backing_store_;
68  base::WeakPtrFactory<IndexedDBActiveBlobRegistry> weak_factory_;
69
70  DISALLOW_COPY_AND_ASSIGN(IndexedDBActiveBlobRegistry);
71};
72
73}  // namespace content
74
75#endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_ACTIVE_BLOB_REGISTRY_H_
76