gecko/storage/src/mozStorageService.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Oracle Corporation code.
 *
 * The Initial Developer of the Original Code is
 *  Oracle Corporation
 * Portions created by the Initial Developer are Copyright (C) 2004
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Vladimir Vukicevic <vladimir.vukicevic@oracle.com>
 *   Brett Wilson <brettw@gmail.com>
 *   Shawn Wilsher <me@shawnwilsher.com>
 *   Drew Willcoxon <adw@mozilla.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef MOZSTORAGESERVICE_H
#define MOZSTORAGESERVICE_H

#include "nsCOMPtr.h"
#include "nsICollation.h"
#include "nsIFile.h"
#include "nsIObserver.h"
#include "mozilla/Mutex.h"

#include "mozIStorageService.h"
#include "mozIStorageServiceQuotaManagement.h"

class nsIXPConnect;
struct sqlite3_vfs;

namespace mozilla {
namespace storage {

class Service : public mozIStorageService
              , public nsIObserver
              , public mozIStorageServiceQuotaManagement
{
public:
  /**
   * Initializes the service.  This must be called before any other function!
   */
  nsresult initialize();

  /**
   * Compares two strings using the Service's locale-aware collation.
   *
   * @param  aStr1
   *         The string to be compared against aStr2.
   * @param  aStr2
   *         The string to be compared against aStr1.
   * @param  aComparisonStrength
   *         The sorting strength, one of the nsICollation constants.
   * @return aStr1 - aStr2.  That is, if aStr1 < aStr2, returns a negative
   *         number.  If aStr1 > aStr2, returns a positive number.  If
   *         aStr1 == aStr2, returns 0.
   */
  int localeCompareStrings(const nsAString &aStr1,
                           const nsAString &aStr2,
                           PRInt32 aComparisonStrength);

  static Service *getSingleton();

  NS_DECL_ISUPPORTS
  NS_DECL_MOZISTORAGESERVICE
  NS_DECL_NSIOBSERVER
  NS_DECL_MOZISTORAGESERVICEQUOTAMANAGEMENT

  /**
   * Obtains an already AddRefed pointer to XPConnect.  This is used by
   * language helpers.
   */
  static already_AddRefed<nsIXPConnect> getXPConnect();

  /**
   * Obtains the cached data for the toolkit.storage.synchronous preference.
   */
  static PRInt32 getSynchronousPref();

private:
  Service();
  virtual ~Service();

  /**
   * Used for 1) locking around calls when initializing connections so that we
   * can ensure that the state of sqlite3_enable_shared_cache is sane and 2)
   * synchronizing access to mLocaleCollation.
   */
  Mutex mMutex;
  
  sqlite3_vfs *mSqliteVFS;

  /**
   * Shuts down the storage service, freeing all of the acquired resources.
   */
  void shutdown();

  /**
   * Lazily creates and returns a collation created from the application's
   * locale that all statements of all Connections of this Service may use.
   * Since the collation's lifetime is that of the Service and no statement may
   * execute outside the lifetime of the Service, this method returns a raw
   * pointer.
   */
  nsICollation *getLocaleCollation();

  /**
   * Lazily created collation that all statements of all Connections of this
   * Service may use.  The collation is created from the application's locale.
   *
   * @note Collation implementations are platform-dependent and in general not
   *       thread-safe.  Access to this collation should be synchronized.
   */
  nsCOMPtr<nsICollation> mLocaleCollation;

  nsCOMPtr<nsIFile> mProfileStorageFile;

  static Service *gService;

  static nsIXPConnect *sXPConnect;

  static PRInt32 sSynchronousPref;
};

} // namespace storage
} // namespace mozilla

#endif /* MOZSTORAGESERVICE_H */