/* -*- 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>
 *   Lev Serebryakov <lev@serebryakov.spb.ru>
 *
 * 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 _MOZSTORAGECONNECTION_H_
#define _MOZSTORAGECONNECTION_H_

#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "mozilla/Mutex.h"

#include "nsString.h"
#include "nsInterfaceHashtable.h"
#include "mozIStorageProgressHandler.h"
#include "SQLiteMutex.h"
#include "mozIStorageConnection.h"
#include "mozStorageService.h"

#include "nsIMutableArray.h"

#include "sqlite3.h"

struct PRLock;
class nsIFile;
class nsIEventTarget;
class nsIThread;

namespace mozilla {
namespace storage {

class Connection : public mozIStorageConnection
{
public:
  NS_DECL_ISUPPORTS
  NS_DECL_MOZISTORAGECONNECTION

  Connection(Service *aService);

  /**
   * Creates the connection to the database.
   *
   * @param aDatabaseFile
   *        The nsIFile of the location of the database to open, or create if it
   *        does not exist.  Passing in nsnull here creates an in-memory
   *        database.
   */
  nsresult initialize(nsIFile *aDatabaseFile);

  // fetch the native handle
  sqlite3 *GetNativeConnection() { return mDBConn; }

  /**
   * Lazily creates and returns a background execution thread.  In the future,
   * the thread may be re-claimed if left idle, so you should call this
   * method just before you dispatch and not save the reference.
   *
   * @returns an event target suitable for asynchronous statement execution.
   */
  already_AddRefed<nsIEventTarget> getAsyncExecutionTarget();

  /**
   * Mutex used by asynchronous statements to protect state.  The mutex is
   * declared on the connection object because there is no contention between
   * asynchronous statements (they are serialized on mAsyncExecutionThread).
   */
  Mutex sharedAsyncExecutionMutex;

private:
  ~Connection();

  /**
   * Describes a certain primitive type in the database.
   *
   * Possible Values Are:
   *  INDEX - To check for the existence of an index
   *  TABLE - To check for the existence of a table
   */
  enum DatabaseElementType {
    INDEX,
    TABLE
  };

  /**
   * Determines if the specified primitive exists.
   *
   * @param aElementType
   *        The type of element to check the existence of
   * @param aElementName
   *        The name of the element to check for
   * @returns true if element exists, false otherwise
   */
  nsresult databaseElementExists(enum DatabaseElementType aElementType,
                                 const nsACString& aElementName,
                                 PRBool *_exists);

  bool findFunctionByInstance(nsISupports *aInstance);

  static int sProgressHelper(void *aArg);
  // Generic progress handler
  // Dispatch call to registered progress handler,
  // if there is one. Do nothing in other cases.
  int progressHandler();

  sqlite3 *mDBConn;
  nsCOMPtr<nsIFile> mDatabaseFile;

  /**
   * Protects access to mAsyncExecutionThread.
   */
  PRLock *mAsyncExecutionMutex;

  /**
   * Lazily created thread for asynchronous statement execution.  Consumers
   * should use getAsyncExecutionTarget rather than directly accessing this
   * field.
   */
  nsCOMPtr<nsIThread> mAsyncExecutionThread;
  /**
   * Set to true by Close() prior to actually shutting down the thread.  This
   * lets getAsyncExecutionTarget() know not to hand out any more thread
   * references (or to create the thread in the first place).  This variable
   * should be accessed while holding the mAsyncExecutionMutex.
   */
  PRBool mAsyncExecutionThreadShuttingDown;

  /**
   * Wraps the mutex that SQLite gives us from sqlite3_db_mutex.
   */
  SQLiteMutex mDBMutex;

  /**
   * Tracks if we have a transaction in progress or not.  Access protected by
   * mDBMutex.
   */
  PRBool mTransactionInProgress;

  /**
   * Stores the mapping of a given function by name to its instance.  Access is
   * protected by mDBMutex.
   */
  nsInterfaceHashtable<nsCStringHashKey, nsISupports> mFunctions;

  /**
   * Stores the registered progress handler for the database connection.  Access
   * is protected by mDBMutex.
   */
  nsCOMPtr<mozIStorageProgressHandler> mProgressHandler;

  // This is here for two reasons: 1) It's used to make sure that the
  // connections do not outlive the service.  2) Our custom collating functions
  // call its localeCompareStrings() method.
  nsRefPtr<Service> mStorageService;
};

} // namespace storage
} // namespace mozilla

#endif /* _MOZSTORAGECONNECTION_H_ */