gecko-dev/dom/indexedDB/IndexedDatabaseManager.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_indexeddb_indexeddatabasemanager_h__
#define mozilla_dom_indexeddb_indexeddatabasemanager_h__

#include "nsIObserver.h"

#include "js/TypeDecls.h"
#include "mozilla/Atomics.h"
#include "mozilla/dom/quota/PersistenceType.h"
#include "mozilla/Mutex.h"
#include "nsClassHashtable.h"
#include "nsHashKeys.h"

class nsPIDOMWindow;

namespace mozilla {

class EventChainPostVisitor;

namespace dom {

class TabContext;

namespace quota {

class OriginOrPatternString;

} // namespace quota

namespace indexedDB {

class FileManager;
class FileManagerInfo;

class IndexedDatabaseManager MOZ_FINAL : public nsIObserver
{
  typedef mozilla::dom::quota::OriginOrPatternString OriginOrPatternString;
  typedef mozilla::dom::quota::PersistenceType PersistenceType;

public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSIOBSERVER

  // Returns a non-owning reference.
  static IndexedDatabaseManager*
  GetOrCreate();

  // Returns a non-owning reference.
  static IndexedDatabaseManager*
  Get();

  static bool
  IsClosed();

  static bool
  IsMainProcess()
#ifdef DEBUG
  ;
#else
  {
    return sIsMainProcess;
  }
#endif

  static bool
  InLowDiskSpaceMode()
#ifdef DEBUG
  ;
#else
  {
    return !!sLowDiskSpaceMode;
  }
#endif

  static bool
  InTestingMode();

  already_AddRefed<FileManager>
  GetFileManager(PersistenceType aPersistenceType,
                 const nsACString& aOrigin,
                 const nsAString& aDatabaseName);

  void
  AddFileManager(FileManager* aFileManager);

  void
  InvalidateAllFileManagers();

  void
  InvalidateFileManagers(PersistenceType aPersistenceType,
                         const OriginOrPatternString& aOriginOrPattern);

  void
  InvalidateFileManager(PersistenceType aPersistenceType,
                        const nsACString& aOrigin,
                        const nsAString& aDatabaseName);

  nsresult
  AsyncDeleteFile(FileManager* aFileManager,
                  int64_t aFileId);

  // Don't call this method in real code, it blocks the main thread!
  // It is intended to be used by mochitests to test correctness of the special
  // reference counting of stored blobs/files.
  nsresult
  BlockAndGetFileReferences(PersistenceType aPersistenceType,
                            const nsACString& aOrigin,
                            const nsAString& aDatabaseName,
                            int64_t aFileId,
                            int32_t* aRefCnt,
                            int32_t* aDBRefCnt,
                            int32_t* aSliceRefCnt,
                            bool* aResult);

  static mozilla::Mutex&
  FileMutex()
  {
    IndexedDatabaseManager* mgr = Get();
    NS_ASSERTION(mgr, "Must have a manager here!");

    return mgr->mFileMutex;
  }

  static nsresult
  FireWindowOnError(nsPIDOMWindow* aOwner,
                    EventChainPostVisitor& aVisitor);

  static bool
  TabContextMayAccessOrigin(const mozilla::dom::TabContext& aContext,
                            const nsACString& aOrigin);

  static bool
  DefineIndexedDB(JSContext* aCx, JS::Handle<JSObject*> aGlobal);

private:
  IndexedDatabaseManager();
  ~IndexedDatabaseManager();

  nsresult
  Init();

  void
  Destroy();

  static PLDHashOperator
  InvalidateAndRemoveFileManagers(const nsACString& aKey,
                                  nsAutoPtr<FileManagerInfo>& aValue,
                                  void* aUserArg);

  // Maintains a list of all file managers per origin. This list isn't
  // protected by any mutex but it is only ever touched on the IO thread.
  nsClassHashtable<nsCStringHashKey, FileManagerInfo> mFileManagerInfos;

  // Lock protecting FileManager.mFileInfos and nsDOMFileBase.mFileInfos
  // It's s also used to atomically update FileInfo.mRefCnt, FileInfo.mDBRefCnt
  // and FileInfo.mSliceRefCnt
  mozilla::Mutex mFileMutex;

  static bool sIsMainProcess;
  static mozilla::Atomic<bool> sLowDiskSpaceMode;
};

} // namespace indexedDB
} // namespace dom
} // namespace mozilla

#endif // mozilla_dom_indexeddb_indexeddatabasemanager_h__