gecko-dev/storage/src/mozStorageService.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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 * ***** 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>
 *
 * 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
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 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
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 * ***** END LICENSE BLOCK ***** */

#include "mozStorageService.h"
#include "mozStorageConnection.h"
#include "prinit.h"
#include "nsAutoLock.h"
#include "nsAutoPtr.h"
#include "nsEmbedCID.h"
#include "mozStoragePrivateHelpers.h"
#include "nsIXPConnect.h"
#include "nsIObserverService.h"

#include "sqlite3.h"

#include "nsIPromptService.h"

namespace mozilla {
namespace storage {

////////////////////////////////////////////////////////////////////////////////
//// Service

NS_IMPL_THREADSAFE_ISUPPORTS2(
  Service,
  mozIStorageService,
  nsIObserver
)

Service *Service::gService = nsnull;

Service *
Service::getSingleton()
{
  if (gService) {
    NS_ADDREF(gService);
    return gService;
  }

  // Ensure that we are using the same version of SQLite that we compiled with
  // or newer.  Our configure check ensures we are using a new enough version
  // at compile time.
  if (SQLITE_VERSION_NUMBER > ::sqlite3_libversion_number()) {
    nsCOMPtr<nsIPromptService> ps(do_GetService(NS_PROMPTSERVICE_CONTRACTID));
    if (ps) {
      nsAutoString title, message;
      title.AppendASCII("SQLite Version Error");
      message.AppendASCII("The application has been updated, but your version "
                          "of SQLite is too old and the application cannot "
                          "run.");
      (void)ps->Alert(nsnull, title.get(), message.get());
    }
    ::PR_Abort();
  }

  gService = new Service();
  if (gService) {
    NS_ADDREF(gService);
    if (NS_FAILED(gService->initialize()))
      NS_RELEASE(gService);
  }

  return gService;
}

nsIXPConnect *Service::sXPConnect = nsnull;

already_AddRefed<nsIXPConnect>
Service::getXPConnect()
{
  NS_ASSERTION(gService,
               "Can not get XPConnect without an instance of our service!");

  // If we've been shutdown, sXPConnect will be null.  To prevent leaks, we do
  // not cache the service after this point.
  nsCOMPtr<nsIXPConnect> xpc(sXPConnect);
  if (!xpc)
    xpc = do_GetService(nsIXPConnect::GetCID());
  NS_ASSERTION(xpc, "Could not get XPConnect!");
  return xpc.forget();
}

Service::~Service()
{
  // Shutdown the sqlite3 API.  Warn if shutdown did not turn out okay, but
  // there is nothing actionable we can do in that case.
  int rc = ::sqlite3_shutdown();
  if (rc != SQLITE_OK)
    NS_WARNING("sqlite3 did not shutdown cleanly.");

  gService = nsnull;
  ::PR_DestroyLock(mLock);
}

void
Service::shutdown()
{
  NS_IF_RELEASE(sXPConnect);
}

nsresult
Service::initialize()
{
  mLock = ::PR_NewLock();
  NS_ENSURE_TRUE(mLock, NS_ERROR_OUT_OF_MEMORY);

  // Disable memory allocation statistic collection, improving performance.
  // This must be done prior to a call to sqlite3_initialize to have any
  // effect.
  int rc = ::sqlite3_config(SQLITE_CONFIG_MEMSTATUS, 0);
  if (rc != SQLITE_OK)
    return ConvertResultCode(rc);

  // Explicitly initialize sqlite3.  Although this is implicitly called by
  // various sqlite3 functions (and the sqlite3_open calls in our case),
  // the documentation suggests calling this directly.  So we do.
  rc = ::sqlite3_initialize();
  if (rc != SQLITE_OK)
    return ConvertResultCode(rc);

  // This makes multiple connections to the same database share the same pager
  // cache.  We do not need to lock here with mLock because this function is
  // only ever called from Service::GetSingleton, which will only
  // call this function once, and will not return until this function returns.
  // (It does not matter where this is called relative to sqlite3_initialize.)
  rc = ::sqlite3_enable_shared_cache(1);
  if (rc != SQLITE_OK)
    return ConvertResultCode(rc);

  nsCOMPtr<nsIObserverService> os =
    do_GetService("@mozilla.org/observer-service;1");
  NS_ENSURE_TRUE(os, NS_ERROR_FAILURE);

  nsresult rv = os->AddObserver(this, "xpcom-shutdown", PR_FALSE);
  NS_ENSURE_SUCCESS(rv, rv);

  // We cache XPConnect for our language helpers.
  (void)CallGetService(nsIXPConnect::GetCID(), &sXPConnect);
  return NS_OK;
}

////////////////////////////////////////////////////////////////////////////////
//// mozIStorageService

#ifndef NS_APP_STORAGE_50_FILE
#define NS_APP_STORAGE_50_FILE "UStor"
#endif

NS_IMETHODIMP
Service::OpenSpecialDatabase(const char *aStorageKey,
                             mozIStorageConnection **_connection)
{
  nsresult rv;

  nsCOMPtr<nsIFile> storageFile;
  if (::strcmp(aStorageKey, "memory") == 0) {
    // just fall through with NULL storageFile, this will cause the storage
    // connection to use a memory DB.
  }
  else if (::strcmp(aStorageKey, "profile") == 0) {

    rv = NS_GetSpecialDirectory(NS_APP_STORAGE_50_FILE,
                                getter_AddRefs(storageFile));
    NS_ENSURE_SUCCESS(rv, rv);

    nsString filename;
    storageFile->GetPath(filename);
    nsCString filename8 = NS_ConvertUTF16toUTF8(filename.get());
    // fall through to DB initialization
  }
  else {
    return NS_ERROR_INVALID_ARG;
  }

  mozStorageConnection *msc = new mozStorageConnection(this);
  NS_ENSURE_TRUE(msc, NS_ERROR_OUT_OF_MEMORY);

  rv = msc->Initialize(storageFile);
  NS_ENSURE_SUCCESS(rv, rv);

  NS_ADDREF(*_connection = msc);
  return NS_OK;
}

NS_IMETHODIMP
Service::OpenDatabase(nsIFile *aDatabaseFile,
                      mozIStorageConnection **_connection)
{
  nsRefPtr<mozStorageConnection> msc = new mozStorageConnection(this);
  NS_ENSURE_TRUE(msc, NS_ERROR_OUT_OF_MEMORY);

  {
    nsAutoLock lock(mLock);
    nsresult rv = msc->Initialize(aDatabaseFile);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  NS_ADDREF(*_connection = msc);
  return NS_OK;
}

NS_IMETHODIMP
Service::OpenUnsharedDatabase(nsIFile *aDatabaseFile,
                              mozIStorageConnection **_connection)
{
  nsRefPtr<mozStorageConnection> msc = new mozStorageConnection(this);
  NS_ENSURE_TRUE(msc, NS_ERROR_OUT_OF_MEMORY);

  // Initialize the connection, temporarily turning off shared caches so the
  // new connection gets its own cache.  Database connections are assigned
  // caches when they are opened, and they retain those caches for their
  // lifetimes, unaffected by changes to the shared caches setting, so we can
  // disable shared caches temporarily while we initialize the new connection
  // without affecting the caches currently in use by other connections.
  nsresult rv;
  {
    nsAutoLock lock(mLock);
    int rc = ::sqlite3_enable_shared_cache(0);
    if (rc != SQLITE_OK)
      return ConvertResultCode(rc);

    rv = msc->Initialize(aDatabaseFile);

    rc = ::sqlite3_enable_shared_cache(1);
    if (rc != SQLITE_OK)
      return ConvertResultCode(rc);
  }
  NS_ENSURE_SUCCESS(rv, rv);

  NS_ADDREF(*_connection = msc);
  return NS_OK;
}

NS_IMETHODIMP
Service::BackupDatabaseFile(nsIFile *aDBFile,
                            const nsAString &aBackupFileName,
                            nsIFile *aBackupParentDirectory,
                            nsIFile **backup)
{
  nsresult rv;
  nsCOMPtr<nsIFile> parentDir = aBackupParentDirectory;
  if (!parentDir) {
    // This argument is optional, and defaults to the same parent directory
    // as the current file.
    rv = aDBFile->GetParent(getter_AddRefs(parentDir));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  nsCOMPtr<nsIFile> backupDB;
  rv = parentDir->Clone(getter_AddRefs(backupDB));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = backupDB->Append(aBackupFileName);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = backupDB->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0600);
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString fileName;
  rv = backupDB->GetLeafName(fileName);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = backupDB->Remove(PR_FALSE);
  NS_ENSURE_SUCCESS(rv, rv);

  backupDB.forget(backup);

  return aDBFile->CopyTo(parentDir, fileName);
}

////////////////////////////////////////////////////////////////////////////////
//// nsIObserver

NS_IMETHODIMP
Service::Observe(nsISupports *, const char *aTopic, const PRUnichar *)
{
  if (strcmp(aTopic, "xpcom-shutdown") == 0)
    shutdown();
  return NS_OK;
}

} // namespace storage
} // namespace mozilla