content/browser/indexed_db/indexed_db_active_blob_registry.h

   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 "webkit/common/blob/shareable_file_reference.h"
  16
  17 namespace content {
  18
  19 class IndexedDBBackingStore;
  20
  21 class CONTENT_EXPORT IndexedDBActiveBlobRegistry {
  22  public:
  23   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   webkit_blob::ShareableFileReference::FinalReleaseCallback
  35       GetFinalReleaseCallback(int64 database_id, int64 blob_key);
  36   // This closure holds a raw pointer to the IndexedDBActiveBlobRegistry,
  37   // and may not be called after it is deleted.
  38   base::Closure GetAddBlobRefCallback(int64 database_id, int64 blob_key);
  39   // Call this to force the registry to drop its use counts, permitting the
  40   // factory to drop any blob-related refcount for the backing store.
  41   // This will also turn any outstanding callbacks into no-ops.
  42   void ForceShutdown();
  43
  44  private:
  45   void AddBlobRef(int64 database_id, int64 blob_key);
  46   void ReleaseBlobRef(int64 database_id, int64 blob_key);
  47   static void ReleaseBlobRefThreadSafe(
  48       scoped_refptr<base::TaskRunner> task_runner,
  49       base::WeakPtr<IndexedDBActiveBlobRegistry> weak_ptr,
  50       int64 database_id,
  51       int64 blob_key,
  52       const base::FilePath& unused);
  53
  54   // Maps blob_key -> IsDeleted; if the record's absent, it's not in active use
  55   // and we don't care if it's deleted.
  56   typedef std::map<int64, bool> SingleDBMap;
  57   // Maps DB ID -> SingleDBMap
  58   typedef std::map<int64, SingleDBMap> AllDBsMap;
  59   typedef std::set<int64> DeletedDBSet;
  60
  61   AllDBsMap use_tracker_;
  62   DeletedDBSet deleted_dbs_;
  63   // As long as we've got blobs registered in use_tracker_,
  64   // backing_store_->factory() will keep backing_store_ alive for us.  And
  65   // backing_store_ owns us, so we'll stay alive as long as we're needed.
  66   IndexedDBBackingStore* backing_store_;
  67   base::WeakPtrFactory<IndexedDBActiveBlobRegistry> weak_factory_;
  68
  69   DISALLOW_COPY_AND_ASSIGN(IndexedDBActiveBlobRegistry);
  70 };
  71
  72 }  // namespace content
  73
  74 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_ACTIVE_BLOB_REGISTRY_H_