gecko-dev/toolkit/components/places/src/nsNavHistory.cpp

//* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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 Mozilla History System.
 *
 * The Initial Developer of the Original Code is Google Inc.
 * Portions created by the Initial Developer are Copyright (C) 2005
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Brett Wilson <brettw@gmail.com> (original author)
 *   Dietrich Ayala <dietrich@mozilla.com>
 *   Seth Spitzer <sspitzer@mozilla.com>
 *   Asaf Romano <mano@mozilla.com>
 *   Marco Bonardo <mak77@bonardo.net>
 *   Edward Lee <edward.lee@engineering.uiuc.edu>
 *
 * 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 ***** */

#include <stdio.h>
#include "nsNavHistory.h"
#include "nsNavBookmarks.h"
#include "nsAnnotationService.h"
#include "nsPlacesTables.h"

#include "nsIArray.h"
#include "nsArrayEnumerator.h"
#include "nsCollationCID.h"
#include "nsCOMPtr.h"
#include "nsCRT.h"
#include "nsDateTimeFormatCID.h"
#include "nsDebug.h"
#include "nsEnumeratorUtils.h"
#include "nsFaviconService.h"
#include "nsIChannelEventSink.h"
#include "nsIComponentManager.h"
#include "nsILocaleService.h"
#include "nsILocalFile.h"
#include "nsIPrefBranch2.h"
#include "nsIServiceManager.h"
#include "nsISimpleEnumerator.h"
#include "nsISupportsPrimitives.h"
#include "nsIURI.h"
#include "nsIURL.h"
#include "nsNetUtil.h"
#include "nsPrintfCString.h"
#include "nsPromiseFlatString.h"
#include "nsString.h"
#include "nsUnicharUtils.h"
#include "prsystem.h"
#include "prtime.h"
#include "prprf.h"
#include "nsEscape.h"
#include "nsIVariant.h"
#include "nsVariant.h"
#include "nsIEffectiveTLDService.h"
#include "nsIIDNService.h"

#include "mozIStorageService.h"
#include "mozIStorageConnection.h"
#include "mozIStorageValueArray.h"
#include "mozIStorageStatement.h"
#include "mozIStorageFunction.h"
#include "mozStorageCID.h"
#include "mozStorageHelper.h"
#include "nsPlacesTriggers.h"
#include "nsAppDirectoryServiceDefs.h"
#include "nsIIdleService.h"
#include "nsILivemarkService.h"

#include "nsMathUtils.h" // for NS_ceilf()

// Microsecond timeout for "recent" events such as typed and bookmark following.
// If you typed it more than this time ago, it's not recent.
// This is 15 minutes           m    s/m  us/s
#define RECENT_EVENT_THRESHOLD (15 * 60 * 1000000)

// Microseconds ago to look for redirects when updating bookmarks. Used to
// compute the threshold for nsNavBookmarks::AddBookmarkToHash
#define BOOKMARK_REDIRECT_TIME_THRESHOLD (2 * 60 * 100000)

// The maximum number of things that we will store in the recent events list
// before calling ExpireNonrecentEvents. This number should be big enough so it
// is very difficult to get that many unconsumed events (for example, typed but
// never visited) in the RECENT_EVENT_THRESHOLD. Otherwise, we'll start
// checking each one for every page visit, which will be somewhat slower.
#define RECENT_EVENT_QUEUE_MAX_LENGTH 128

// preference ID strings
#define PREF_BRANCH_BASE                        "browser."
#define PREF_BROWSER_HISTORY_EXPIRE_DAYS_MIN    "history_expire_days_min"
#define PREF_BROWSER_HISTORY_EXPIRE_DAYS_MAX    "history_expire_days"
#define PREF_BROWSER_HISTORY_EXPIRE_SITES       "history_expire_sites"
#define PREF_AUTOCOMPLETE_ONLY_TYPED            "urlbar.matchOnlyTyped"
#define PREF_AUTOCOMPLETE_MATCH_BEHAVIOR        "urlbar.matchBehavior"
#define PREF_AUTOCOMPLETE_FILTER_JAVASCRIPT     "urlbar.filter.javascript"
#define PREF_AUTOCOMPLETE_ENABLED               "urlbar.autocomplete.enabled"
#define PREF_AUTOCOMPLETE_MAX_RICH_RESULTS      "urlbar.maxRichResults"
#define PREF_AUTOCOMPLETE_RESTRICT_HISTORY      "urlbar.restrict.history"
#define PREF_AUTOCOMPLETE_RESTRICT_BOOKMARK     "urlbar.restrict.bookmark"
#define PREF_AUTOCOMPLETE_RESTRICT_TAG          "urlbar.restrict.tag"
#define PREF_AUTOCOMPLETE_MATCH_TITLE           "urlbar.match.title"
#define PREF_AUTOCOMPLETE_MATCH_URL             "urlbar.match.url"
#define PREF_AUTOCOMPLETE_SEARCH_CHUNK_SIZE     "urlbar.search.chunkSize"
#define PREF_AUTOCOMPLETE_SEARCH_TIMEOUT        "urlbar.search.timeout"
#define PREF_DB_CACHE_PERCENTAGE                "history_cache_percentage"
#define PREF_FRECENCY_NUM_VISITS                "places.frecency.numVisits"
#define PREF_FRECENCY_CALC_ON_IDLE              "places.frecency.numCalcOnIdle"
#define PREF_FRECENCY_CALC_ON_MIGRATE           "places.frecency.numCalcOnMigrate"
#define PREF_FRECENCY_UPDATE_IDLE_TIME          "places.frecency.updateIdleTime"
#define PREF_FRECENCY_FIRST_BUCKET_CUTOFF       "places.frecency.firstBucketCutoff"
#define PREF_FRECENCY_SECOND_BUCKET_CUTOFF      "places.frecency.secondBucketCutoff"
#define PREF_FRECENCY_THIRD_BUCKET_CUTOFF       "places.frecency.thirdBucketCutoff"
#define PREF_FRECENCY_FOURTH_BUCKET_CUTOFF      "places.frecency.fourthBucketCutoff"
#define PREF_FRECENCY_FIRST_BUCKET_WEIGHT       "places.frecency.firstBucketWeight"
#define PREF_FRECENCY_SECOND_BUCKET_WEIGHT      "places.frecency.secondBucketWeight"
#define PREF_FRECENCY_THIRD_BUCKET_WEIGHT       "places.frecency.thirdBucketWeight"
#define PREF_FRECENCY_FOURTH_BUCKET_WEIGHT      "places.frecency.fourthBucketWeight"
#define PREF_FRECENCY_DEFAULT_BUCKET_WEIGHT     "places.frecency.defaultBucketWeight"
#define PREF_FRECENCY_EMBED_VISIT_BONUS         "places.frecency.embedVisitBonus"
#define PREF_FRECENCY_LINK_VISIT_BONUS          "places.frecency.linkVisitBonus"
#define PREF_FRECENCY_TYPED_VISIT_BONUS         "places.frecency.typedVisitBonus"
#define PREF_FRECENCY_BOOKMARK_VISIT_BONUS      "places.frecency.bookmarkVisitBonus"
#define PREF_FRECENCY_DOWNLOAD_VISIT_BONUS      "places.frecency.downloadVisitBonus"
#define PREF_FRECENCY_PERM_REDIRECT_VISIT_BONUS "places.frecency.permRedirectVisitBonus"
#define PREF_FRECENCY_TEMP_REDIRECT_VISIT_BONUS "places.frecency.tempRedirectVisitBonus"
#define PREF_FRECENCY_DEFAULT_VISIT_BONUS       "places.frecency.defaultVisitBonus"
#define PREF_FRECENCY_UNVISITED_BOOKMARK_BONUS  "places.frecency.unvisitedBookmarkBonus"
#define PREF_FRECENCY_UNVISITED_TYPED_BONUS     "places.frecency.unvisitedTypedBonus"
#define PREF_BROWSER_IMPORT_BOOKMARKS           "browser.places.importBookmarksHTML"
#define PREF_BROWSER_IMPORT_DEFAULTS            "browser.places.importDefaults"
#define PREF_BROWSER_SMARTBOOKMARKSVERSION      "browser.places.smartBookmarksVersion"
#define PREF_BROWSER_LEFTPANEFOLDERID           "browser.places.leftPaneFolderId"

// Default (integer) value of PREF_DB_CACHE_PERCENTAGE from 0-100
// This is 6% of machine memory, giving 15MB for a user with 256MB of memory.
// The most that will be used is the size of the DB file. Normal history sizes
// look like 10MB would be a high average for a typical user, so the maximum
// should not normally be required.
#define DEFAULT_DB_CACHE_PERCENTAGE 6

// We set the default database page size to be larger. sqlite's default is 1K.
// This gives good performance when many small parts of the file have to be
// loaded for each statement. Because we try to keep large chunks of the file
// in memory, a larger page size should give better I/O performance. 32K is
// sqlite's default max page size.
#define DEFAULT_DB_PAGE_SIZE 4096

// the value of mLastNow expires every 3 seconds
#define HISTORY_EXPIRE_NOW_TIMEOUT (3 * PR_MSEC_PER_SEC)

// see bug #319004 -- clamp title and URL to generously-large but not too large
// length
#define HISTORY_URI_LENGTH_MAX 65536
#define HISTORY_TITLE_LENGTH_MAX 4096

// db file name
#define DB_FILENAME NS_LITERAL_STRING("places.sqlite")

// db backup file name
#define DB_CORRUPT_FILENAME NS_LITERAL_STRING("places.sqlite.corrupt")

// Lazy adding

#ifdef LAZY_ADD

// time that we'll wait before committing messages
#define LAZY_MESSAGE_TIMEOUT (3 * PR_MSEC_PER_SEC)

// the maximum number of times we'll postpone a lazy timer before committing
// See StartLazyTimer()
#define MAX_LAZY_TIMER_DEFERMENTS 2

#endif // LAZY_ADD

// Perform "long idle" tasks after 15 minutes of idle time, repeating.
// 15 minutes = 900 seconds = 900000 milliseconds
#define LONG_IDLE_TIME_IN_MSECS (900000)

// Perform expiration after 5 minutes of idle time, repeating.
// 5 minutes = 300 seconds = 300000 milliseconds
#define EXPIRE_IDLE_TIME_IN_MSECS (300000)

// Amount of items to expire at idle time.
#define MAX_EXPIRE_RECORDS_ON_IDLE 200

// Limit the number of items in the history for performance reasons
#define EXPIRATION_CAP_SITES 40000

// DB migration types
#define DB_MIGRATION_NONE    0
#define DB_MIGRATION_CREATED 1
#define DB_MIGRATION_UPDATED 2

// character-set annotation
#define CHARSET_ANNO NS_LITERAL_CSTRING("URIProperties/characterSet")

NS_IMPL_ADDREF(nsNavHistory)
NS_IMPL_RELEASE(nsNavHistory)

NS_INTERFACE_MAP_BEGIN(nsNavHistory)
  NS_INTERFACE_MAP_ENTRY(nsINavHistoryService)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsIGlobalHistory2, nsIGlobalHistory3)
  NS_INTERFACE_MAP_ENTRY(nsIGlobalHistory3)
  NS_INTERFACE_MAP_ENTRY(nsIDownloadHistory)
  NS_INTERFACE_MAP_ENTRY(nsIBrowserHistory)
  NS_INTERFACE_MAP_ENTRY(nsIObserver)
  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
  NS_INTERFACE_MAP_ENTRY(nsICharsetResolver)
  NS_INTERFACE_MAP_ENTRY(nsPIPlacesDatabase)
#ifdef MOZ_XUL
  NS_INTERFACE_MAP_ENTRY(nsIAutoCompleteSearch)
  NS_INTERFACE_MAP_ENTRY(nsIAutoCompleteSimpleResultListener)
#endif
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsINavHistoryService)
NS_INTERFACE_MAP_END

static nsresult GetReversedHostname(nsIURI* aURI, nsAString& host);
static void GetReversedHostname(const nsString& aForward, nsAString& aReversed);
static nsresult GenerateTitleFromURI(nsIURI* aURI, nsAString& aTitle);
static PRInt64 GetSimpleBookmarksQueryFolder(
    const nsCOMArray<nsNavHistoryQuery>& aQueries,
    nsNavHistoryQueryOptions* aOptions);
static void ParseSearchTermsFromQueries(const nsCOMArray<nsNavHistoryQuery>& aQueries,
                                        nsTArray<nsStringArray*>* aTerms);

inline void ReverseString(const nsString& aInput, nsAString& aReversed)
{
  aReversed.Truncate(0);
  for (PRInt32 i = aInput.Length() - 1; i >= 0; i --)
    aReversed.Append(aInput[i]);
}

// UpdateBatchScoper
//
//    This just sets begin/end of batch updates to correspond to C++ scopes so
//    we can be sure end always gets called.

class UpdateBatchScoper
{
public:
  UpdateBatchScoper(nsNavHistory& aNavHistory) : mNavHistory(aNavHistory)
  {
    mNavHistory.BeginUpdateBatch();
  }
  ~UpdateBatchScoper()
  {
    mNavHistory.EndUpdateBatch();
  }
protected:
  nsNavHistory& mNavHistory;
};

// if adding a new one, be sure to update nsNavBookmarks statements and
// its kGetChildrenIndex_* constants
const PRInt32 nsNavHistory::kGetInfoIndex_PageID = 0;
const PRInt32 nsNavHistory::kGetInfoIndex_URL = 1;
const PRInt32 nsNavHistory::kGetInfoIndex_Title = 2;
const PRInt32 nsNavHistory::kGetInfoIndex_RevHost = 3;
const PRInt32 nsNavHistory::kGetInfoIndex_VisitCount = 4;
const PRInt32 nsNavHistory::kGetInfoIndex_VisitDate = 5;
const PRInt32 nsNavHistory::kGetInfoIndex_FaviconURL = 6;
const PRInt32 nsNavHistory::kGetInfoIndex_SessionId = 7;
const PRInt32 nsNavHistory::kGetInfoIndex_ItemId = 8;
const PRInt32 nsNavHistory::kGetInfoIndex_ItemDateAdded = 9;
const PRInt32 nsNavHistory::kGetInfoIndex_ItemLastModified = 10;

const PRInt32 nsNavHistory::kAutoCompleteIndex_URL = 0;
const PRInt32 nsNavHistory::kAutoCompleteIndex_Title = 1;
const PRInt32 nsNavHistory::kAutoCompleteIndex_FaviconURL = 2;
const PRInt32 nsNavHistory::kAutoCompleteIndex_ParentId = 3;
const PRInt32 nsNavHistory::kAutoCompleteIndex_BookmarkTitle = 4;
const PRInt32 nsNavHistory::kAutoCompleteIndex_Tags = 5;
const PRInt32 nsNavHistory::kAutoCompleteIndex_VisitCount = 6;

static const char* gQuitApplicationMessage = "quit-application";
static const char* gXpcomShutdown = "xpcom-shutdown";
static const char* gAutoCompleteFeedback = "autocomplete-will-enter-text";

// annotation names
const char nsNavHistory::kAnnotationPreviousEncoding[] = "history/encoding";

// code borrowed from mozilla/xpfe/components/history/src/nsGlobalHistory.cpp
// pass in a pre-normalized now and a date, and we'll find
// the difference since midnight on each of the days.
//
// USECS_PER_DAY == PR_USEC_PER_SEC * 60 * 60 * 24;
static const PRInt64 USECS_PER_DAY = LL_INIT(20, 500654080);

nsNavHistory *nsNavHistory::gHistoryService = nsnull;

nsNavHistory *
nsNavHistory::GetSingleton()
{
  if (gHistoryService) {
    NS_ADDREF(gHistoryService);
    return gHistoryService;
  }

  gHistoryService = new nsNavHistory();
  if (gHistoryService) {
    NS_ADDREF(gHistoryService);
    if (NS_FAILED(gHistoryService->Init()))
      NS_RELEASE(gHistoryService);
  }

  return gHistoryService;
}

// nsNavHistory::nsNavHistory

nsNavHistory::nsNavHistory() : mBatchLevel(0),
                               mBatchHasTransaction(PR_FALSE),
                               mNowValid(PR_FALSE),
                               mExpireNowTimer(nsnull),
                               mExpire(this),
                               mAutoCompleteOnlyTyped(PR_FALSE),
                               mAutoCompleteMatchBehavior(MATCH_BOUNDARY_ANYWHERE),
                               mAutoCompleteMaxResults(25),
                               mAutoCompleteRestrictHistory(NS_LITERAL_STRING("^")),
                               mAutoCompleteRestrictBookmark(NS_LITERAL_STRING("*")),
                               mAutoCompleteRestrictTag(NS_LITERAL_STRING("+")),
                               mAutoCompleteMatchTitle(NS_LITERAL_STRING("#")),
                               mAutoCompleteMatchUrl(NS_LITERAL_STRING("@")),
                               mAutoCompleteSearchChunkSize(100),
                               mAutoCompleteSearchTimeout(100),
                               mRestrictHistory(PR_FALSE),
                               mRestrictBookmark(PR_FALSE),
                               mRestrictTag(PR_FALSE),
                               mMatchTitle(PR_FALSE),
                               mMatchUrl(PR_FALSE),
                               mPreviousChunkOffset(-1),
                               mAutoCompleteFinishedSearch(PR_FALSE),
                               mExpireDaysMin(0),
                               mExpireDaysMax(0),
                               mExpireSites(0),
                               mNumVisitsForFrecency(10),
                               mTagsFolder(-1)
{
#ifdef LAZY_ADD
  mLazyTimerSet = PR_TRUE;
  mLazyTimerDeferments = 0;
#endif
  NS_ASSERTION(! gHistoryService, "YOU ARE CREATING 2 COPIES OF THE HISTORY SERVICE. Everything will break.");
  gHistoryService = this;
}


// nsNavHistory::~nsNavHistory

nsNavHistory::~nsNavHistory()
{
  // remove the static reference to the service. Check to make sure its us
  // in case somebody creates an extra instance of the service.
  NS_ASSERTION(gHistoryService == this, "YOU CREATED 2 COPIES OF THE HISTORY SERVICE.");
  gHistoryService = nsnull;
}


// nsNavHistory::Init

nsresult
nsNavHistory::Init()
{
  nsresult rv;

  // prefs (must be before DB init, which uses the pref service)
  nsCOMPtr<nsIPrefService> prefService =
    do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = prefService->GetBranch(PREF_BRANCH_BASE, getter_AddRefs(mPrefBranch));
  NS_ENSURE_SUCCESS(rv, rv);

  // prefs
  LoadPrefs(PR_TRUE);

  // init db file
  rv = InitDBFile(PR_FALSE);
  NS_ENSURE_SUCCESS(rv, rv);

  // init db and statements
  PRInt16 migrationType;
  rv = InitDB(&migrationType);
  if (NS_FAILED(rv)) {
    // if unable to initialize the db, force-re-initialize it:
    // InitDBFile will backup the old db and create a new one.
    rv = InitDBFile(PR_TRUE);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = InitDB(&migrationType);
  }
  NS_ENSURE_SUCCESS(rv, rv);

#ifdef MOZ_XUL
  rv = InitAutoComplete();
  NS_ENSURE_SUCCESS(rv, rv);
#endif

  // extract the last session ID so we know where to pick up. There is no index
  // over sessions so the naive statement "SELECT MAX(session) FROM
  // moz_historyvisits" won't have good performance. Instead we select the
  // session of the last visited page because we do have indices over dates.
  // We still do MAX(session) in case there are duplicate sessions for the same
  // date, but there will generally be very few (1) of these.
  {
    nsCOMPtr<mozIStorageStatement> selectSession;
    rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
        "SELECT MAX(session) FROM moz_historyvisits "
        "WHERE visit_date = "
        "(SELECT MAX(visit_date) from moz_historyvisits)"),
      getter_AddRefs(selectSession));
    NS_ENSURE_SUCCESS(rv, rv);
    PRBool hasSession;
    if (NS_SUCCEEDED(selectSession->ExecuteStep(&hasSession)) && hasSession)
      mLastSessionID = selectSession->AsInt64(0);
    else
      mLastSessionID = 1;
  }

  // string bundle for localization
  nsCOMPtr<nsIStringBundleService> bundleService =
    do_GetService(NS_STRINGBUNDLE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = bundleService->CreateBundle(
      "chrome://places/locale/places.properties",
      getter_AddRefs(mBundle));
  NS_ENSURE_SUCCESS(rv, rv);

  // locale
  nsCOMPtr<nsILocaleService> ls = do_GetService(NS_LOCALESERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = ls->GetApplicationLocale(getter_AddRefs(mLocale));
  NS_ENSURE_SUCCESS(rv, rv);

  // collation
  nsCOMPtr<nsICollationFactory> cfact = do_CreateInstance(
     NS_COLLATIONFACTORY_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = cfact->CreateCollation(mLocale, getter_AddRefs(mCollation));
  NS_ENSURE_SUCCESS(rv, rv);

  // date formatter
  mDateFormatter = do_CreateInstance(NS_DATETIMEFORMAT_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  // initialize idle timer
  InitializeIdleTimer();

  // recent events hash tables
  NS_ENSURE_TRUE(mRecentTyped.Init(128), NS_ERROR_OUT_OF_MEMORY);
  NS_ENSURE_TRUE(mRecentBookmark.Init(128), NS_ERROR_OUT_OF_MEMORY);
  NS_ENSURE_TRUE(mRecentRedirects.Init(128), NS_ERROR_OUT_OF_MEMORY);

  /*****************************************************************************
   *** IMPORTANT NOTICE!
   ***
   *** Nothing after these add observer calls should return anything but NS_OK.
   *** If a failure code is returned, this nsNavHistory object will be held onto
   *** by the observer service and the preference service. 
   ****************************************************************************/

  nsCOMPtr<nsIObserverService> observerService =
    do_GetService("@mozilla.org/observer-service;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIPrefBranch2> pbi = do_QueryInterface(mPrefBranch);
  if (pbi) {
    pbi->AddObserver(PREF_AUTOCOMPLETE_ONLY_TYPED, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_MATCH_BEHAVIOR, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_FILTER_JAVASCRIPT, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_MAX_RICH_RESULTS, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_RESTRICT_HISTORY, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_RESTRICT_BOOKMARK, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_RESTRICT_TAG, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_MATCH_TITLE, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_MATCH_URL, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_SEARCH_CHUNK_SIZE, this, PR_FALSE);
    pbi->AddObserver(PREF_AUTOCOMPLETE_SEARCH_TIMEOUT, this, PR_FALSE);
    pbi->AddObserver(PREF_BROWSER_HISTORY_EXPIRE_DAYS_MAX, this, PR_FALSE);
    pbi->AddObserver(PREF_BROWSER_HISTORY_EXPIRE_DAYS_MIN, this, PR_FALSE);
    pbi->AddObserver(PREF_BROWSER_HISTORY_EXPIRE_SITES, this, PR_FALSE);
  }

  observerService->AddObserver(this, gQuitApplicationMessage, PR_FALSE);
  observerService->AddObserver(this, gXpcomShutdown, PR_FALSE);
  observerService->AddObserver(this, gAutoCompleteFeedback, PR_FALSE);

  /*****************************************************************************
   *** IMPORTANT NOTICE!
   ***
   *** NO CODE SHOULD GO BEYOND THIS POINT THAT WOULD PROPAGATE AN ERROR.  IN
   *** OTHER WORDS, THE ONLY THING THAT SHOULD BE RETURNED AFTER THIS POINT IS
   *** NS_OK.
   ****************************************************************************/

  if (migrationType == DB_MIGRATION_CREATED) {
    nsCOMPtr<nsIFile> historyFile;
    rv = NS_GetSpecialDirectory(NS_APP_HISTORY_50_FILE,
                                getter_AddRefs(historyFile));
    if (NS_SUCCEEDED(rv) && historyFile) {
      ImportHistory(historyFile);
    }
  }

  // In case we've either imported or done a migration from a pre-frecency build,
  // calculate the first cutoff period's frecencies now.
  // Swallow errors here to not block initialization.
  if (migrationType != DB_MIGRATION_NONE)
    (void)RecalculateFrecencies(mNumCalculateFrecencyOnMigrate,
                                PR_FALSE /* don't recalculate old */);

  // Don't add code that can fail here! Do it up above, before we add our
  // observers.

  return NS_OK;
}

// nsNavHistory::InitDBFile
nsresult
nsNavHistory::InitDBFile(PRBool aForceInit)
{
  if (aForceInit) {
    NS_ASSERTION(mDBConn,
                 "When forcing initialization, a database connection must exist!");
    NS_ASSERTION(mDBService,
                 "When forcing initialization, the database service must exist!");
  }

  // get profile dir, file
  nsCOMPtr<nsIFile> profDir;
  nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
                                       getter_AddRefs(profDir));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = profDir->Clone(getter_AddRefs(mDBFile));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = mDBFile->Append(DB_FILENAME);
  NS_ENSURE_SUCCESS(rv, rv);
  
  // if forcing, backup and remove the old file
  PRBool dbExists;
  if (aForceInit) {
    // backup the database
    nsCOMPtr<nsIFile> backup;
    rv = mDBService->BackupDatabaseFile(mDBFile, DB_CORRUPT_FILENAME, profDir,
                                        getter_AddRefs(backup));
    NS_ENSURE_SUCCESS(rv, rv);

    // close database connection if open
    rv = mDBConn->Close();
    NS_ENSURE_SUCCESS(rv, rv);

    // and remove the file
    rv = mDBFile->Remove(PR_FALSE);
    NS_ENSURE_SUCCESS(rv, rv);
    dbExists = PR_FALSE;
  }
  else {
    // file exists?
    rv = mDBFile->Exists(&dbExists);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  
  // open the database
  mDBService = do_GetService(MOZ_STORAGE_SERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = mDBService->OpenUnsharedDatabase(mDBFile, getter_AddRefs(mDBConn));
  if (rv == NS_ERROR_FILE_CORRUPTED) {
    dbExists = PR_FALSE;
  
    // backup file
    nsCOMPtr<nsIFile> backup;
    rv = mDBService->BackupDatabaseFile(mDBFile, DB_CORRUPT_FILENAME, profDir,
                                        getter_AddRefs(backup));
    NS_ENSURE_SUCCESS(rv, rv);
 
    // remove existing file 
    rv = mDBFile->Remove(PR_FALSE);
    NS_ENSURE_SUCCESS(rv, rv);

    // and try again
    rv = profDir->Clone(getter_AddRefs(mDBFile));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBFile->Append(DB_FILENAME);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBService->OpenUnsharedDatabase(mDBFile, getter_AddRefs(mDBConn));
  }
  NS_ENSURE_SUCCESS(rv, rv);
  
  // if the db didn't previously exist, or was corrupted, re-import bookmarks.
  if (!dbExists) {
    nsCOMPtr<nsIPrefBranch> prefs(do_GetService("@mozilla.org/preferences-service;1"));
    if (prefs) {
      rv = prefs->SetBoolPref(PREF_BROWSER_IMPORT_BOOKMARKS, PR_TRUE);
      NS_ENSURE_SUCCESS(rv, rv);

      rv = prefs->SetBoolPref(PREF_BROWSER_IMPORT_DEFAULTS, PR_TRUE);
      NS_ENSURE_SUCCESS(rv, rv);  

      // if the places.sqlite gets deleted/corrupted the queries should be created again
      rv = prefs->SetIntPref(PREF_BROWSER_SMARTBOOKMARKSVERSION, 0);
      NS_ENSURE_SUCCESS(rv, rv);  
      
      // we must create a new Organizer left pane folder root, the old will not be valid anymore
      rv = prefs->SetIntPref(PREF_BROWSER_LEFTPANEFOLDERID, -1);
      NS_ENSURE_SUCCESS(rv, rv); 
    }
  }

  return NS_OK;
}

// nsNavHistory::InitDB
//


#define PLACES_SCHEMA_VERSION 7

nsresult
nsNavHistory::InitDB(PRInt16 *aMadeChanges)
{
  nsresult rv;
  PRBool tableExists;
  *aMadeChanges = DB_MIGRATION_NONE;

  // IMPORTANT NOTE:
  // setting page_size must happen first, see bug #401985 for details
  //
  // Set the database page size. This will only have any effect on empty files,
  // so must be done before anything else. If the file already exists, we'll
  // get that file's page size and this will have no effect.
  nsCAutoString pageSizePragma("PRAGMA page_size=");
  pageSizePragma.AppendInt(DEFAULT_DB_PAGE_SIZE);
  rv = mDBConn->ExecuteSimpleSQL(pageSizePragma);
  NS_ENSURE_SUCCESS(rv, rv);

#ifdef IN_MEMORY_SQLITE_TEMP_STORE
  rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "PRAGMA temp_store = MEMORY"));
  NS_ENSURE_SUCCESS(rv, rv);
#endif

  mozStorageTransaction transaction(mDBConn, PR_FALSE);

  // Initialize the other places services' database tables. We do this before
  // creating our statements. Some of our statements depend on these external
  // tables, such as the bookmarks or favicon tables.
  rv = nsNavBookmarks::InitTables(mDBConn);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = nsFaviconService::InitTables(mDBConn);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = nsAnnotationService::InitTables(mDBConn);
  NS_ENSURE_SUCCESS(rv, rv);

  // Initialize the places schema version if this is first run.
  rv = mDBConn->TableExists(NS_LITERAL_CSTRING("moz_places"), &tableExists);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!tableExists) {
    rv = UpdateSchemaVersion();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Get the places schema version, which we store in the user_version PRAGMA
  PRInt32 DBSchemaVersion;
  rv = mDBConn->GetSchemaVersion(&DBSchemaVersion);
  NS_ENSURE_SUCCESS(rv, rv);
   
  if (PLACES_SCHEMA_VERSION != DBSchemaVersion) {
    // Migration How-to:
    //
    // 1. increment PLACES_SCHEMA_VERSION.
    // 2. implement a method that performs up/sidegrade to your version
    //    from the current version.
    //
    // NOTE: We don't support downgrading back to History-only Places.
    // If you want to go from newer schema version back to V0, you'll need to
    // blow away your sqlite file. Subsequent up/downgrades have backwards and
    // forward migration code.
    //
    // XXX Backup places.sqlite to places-{version}.sqlite when doing db migration?
    
    if (DBSchemaVersion < PLACES_SCHEMA_VERSION) {
      // Upgrading

      // Migrate anno tables up to V3
      if (DBSchemaVersion < 3) {
        rv = MigrateV3Up(mDBConn);
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Migrate bookmarks tables up to V5
      if (DBSchemaVersion < 5) {
        rv = ForceMigrateBookmarksDB(mDBConn);
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Migrate anno tables up to V6
      if (DBSchemaVersion < 6) {
        rv = MigrateV6Up(mDBConn);
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Migrate historyvisits and bookmarks up to V7
      if (DBSchemaVersion < 7) {
        rv = MigrateV7Up(mDBConn);
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // XXX Upgrades >V7 must add migration code here.

    } else {
      // Downgrading

      // XXX Need to prompt user or otherwise notify of 
      // potential dataloss when downgrading.

      // XXX Downgrades from >V6 must add migration code here.

      // Downgrade v1,2,4,5
      // v3,6 have no backwards incompatible changes.
      if (DBSchemaVersion > 2 && DBSchemaVersion < 6) {
        // perform downgrade to v2
        rv = ForceMigrateBookmarksDB(mDBConn);
        NS_ENSURE_SUCCESS(rv, rv);
      }
    }

    // update schema version in the db
    rv = UpdateSchemaVersion();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Get the page size. This may be different than was set above if the database
  // file already existed and has a different page size.
  PRInt32 pageSize;
  {
    nsCOMPtr<mozIStorageStatement> statement;
    rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING("PRAGMA page_size"),
                                  getter_AddRefs(statement));
    NS_ENSURE_SUCCESS(rv, rv);

    PRBool hasResult;
    rv = statement->ExecuteStep(&hasResult);
    NS_ENSURE_SUCCESS(rv, rv);
    NS_ENSURE_TRUE(hasResult, NS_ERROR_FAILURE);
    pageSize = statement->AsInt32(0);
  }

  // compute the size of the database cache
  PRInt32 cachePercentage;
  if (NS_FAILED(mPrefBranch->GetIntPref(PREF_DB_CACHE_PERCENTAGE,
                                        &cachePercentage)))
    cachePercentage = DEFAULT_DB_CACHE_PERCENTAGE;
  if (cachePercentage > 50)
    cachePercentage = 50; // sanity check, don't take too much
  if (cachePercentage < 0)
    cachePercentage = 0;
  PRInt64 cacheSize = PR_GetPhysicalMemorySize() * cachePercentage / 100;
  PRInt64 cachePages = cacheSize / pageSize;

  // set the cache size
  nsCAutoString cacheSizePragma("PRAGMA cache_size=");
  cacheSizePragma.AppendInt(cachePages);
  rv = mDBConn->ExecuteSimpleSQL(cacheSizePragma);
  NS_ENSURE_SUCCESS(rv, rv);

  // lock the db file
  // http://www.sqlite.org/pragma.html#pragma_locking_mode
  rv = mDBConn->ExecuteSimpleSQL(
    NS_LITERAL_CSTRING("PRAGMA locking_mode = EXCLUSIVE"));
  NS_ENSURE_SUCCESS(rv, rv);

  // moz_places
  if (!tableExists) {
    *aMadeChanges = DB_MIGRATION_CREATED;
    rv = mDBConn->ExecuteSimpleSQL(CREATE_MOZ_PLACES);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE UNIQUE INDEX moz_places_url_uniqueindex ON moz_places (url)"));
    NS_ENSURE_SUCCESS(rv, rv);

    // This index is used for favicon expiration, see nsNavHistoryExpire::ExpireItems.
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_places_faviconindex ON moz_places (favicon_id)"));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_places_hostindex ON moz_places (rev_host)"));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_places_visitcount ON moz_places (visit_count)"));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_places_frecencyindex ON moz_places (frecency)"));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // moz_historyvisits
  rv = mDBConn->TableExists(NS_LITERAL_CSTRING("moz_historyvisits"), &tableExists);
  NS_ENSURE_SUCCESS(rv, rv);
  if (! tableExists) {
    rv = mDBConn->ExecuteSimpleSQL(CREATE_MOZ_HISTORYVISITS);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_historyvisits_placedateindex "
        "ON moz_historyvisits (place_id, visit_date)"));
    NS_ENSURE_SUCCESS(rv, rv);

    // This makes a big difference in startup time for large profiles because of
    // finding bookmark redirects using the referring page. 
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_historyvisits_fromindex ON moz_historyvisits (from_visit)"));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_historyvisits_dateindex ON moz_historyvisits (visit_date)"));
    NS_ENSURE_SUCCESS(rv, rv);

    // Create our triggers for this table
    rv = mDBConn->ExecuteSimpleSQL(CREATE_VISIT_COUNT_INSERT_TRIGGER);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(CREATE_VISIT_COUNT_DELETE_TRIGGER);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // moz_inputhistory
  rv = mDBConn->TableExists(NS_LITERAL_CSTRING("moz_inputhistory"), &tableExists);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!tableExists) {
    rv = mDBConn->ExecuteSimpleSQL(CREATE_MOZ_INPUTHISTORY);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  PRBool migrated = PR_FALSE;
  rv = EnsureCurrentSchema(mDBConn, &migrated);
  NS_ENSURE_SUCCESS(rv, rv);
  if (migrated && *aMadeChanges != DB_MIGRATION_CREATED)
    *aMadeChanges = DB_MIGRATION_UPDATED;

  rv = transaction.Commit();
  NS_ENSURE_SUCCESS(rv, rv);

  // --- PUT SCHEMA-MODIFYING THINGS (like create table) ABOVE THIS LINE ---

  // DO NOT PUT ANY SCHEMA-MODIFYING THINGS HERE

  rv = InitFunctions();
  NS_ENSURE_SUCCESS(rv, rv);
  rv = InitStatements();
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
nsNavHistory::InitializeIdleTimer()
{
  if (mIdleTimer) {
    mIdleTimer->Cancel();
    mIdleTimer = nsnull;
  }
  nsresult rv;
  mIdleTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  PRInt32 idleTimerTimeout = PR_MIN(LONG_IDLE_TIME_IN_MSECS,
                                    EXPIRE_IDLE_TIME_IN_MSECS);
  if (mFrecencyUpdateIdleTime)
    idleTimerTimeout = PR_MIN(idleTimerTimeout, mFrecencyUpdateIdleTime);

  rv = mIdleTimer->InitWithFuncCallback(IdleTimerCallback, this,
                                        idleTimerTimeout,
                                        nsITimer::TYPE_REPEATING_SLACK);
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

// nsNavHistory::UpdateSchemaVersion
//
// Called by the individual services' InitTables()
nsresult
nsNavHistory::UpdateSchemaVersion()
{
  return mDBConn->SetSchemaVersion(PLACES_SCHEMA_VERSION);
}

// nsNavHistory::InitFunctions
//
//    Called after InitDB, this creates our own functions

class mozStorageFunctionGetUnreversedHost: public mozIStorageFunction
{
public:
  NS_DECL_ISUPPORTS
  NS_DECL_MOZISTORAGEFUNCTION
};

NS_IMPL_ISUPPORTS1(mozStorageFunctionGetUnreversedHost, mozIStorageFunction)

NS_IMETHODIMP mozStorageFunctionGetUnreversedHost::OnFunctionCall(
  mozIStorageValueArray* aFunctionArguments,
  nsIVariant** _retval)
{
  NS_ENSURE_ARG_POINTER(_retval);

  nsAutoString src;
  aFunctionArguments->GetString(0, src);

  nsresult rv;
  nsCOMPtr<nsIWritableVariant> result(do_CreateInstance(
      "@mozilla.org/variant;1", &rv));
  NS_ENSURE_SUCCESS(rv, rv);

  if (src.Length()>1) {
    src.Truncate(src.Length() - 1);
    nsAutoString dest;
    ReverseString(src, dest);
    result->SetAsAString(dest);
  } else {
    result->SetAsAString(NS_LITERAL_STRING(""));
  }
  NS_ADDREF(*_retval = result);
  return NS_OK;
}

nsresult
nsNavHistory::InitFunctions()
{
  nsresult rv;

  rv = mDBConn->CreateFunction(
      NS_LITERAL_CSTRING("get_unreversed_host"), 1, 
      new mozStorageFunctionGetUnreversedHost);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

// nsNavHistory::InitStatements
//
//    Called after InitDB, this creates our stored statements

nsresult
nsNavHistory::InitStatements()
{
  nsresult rv;

  // mDBGetURLPageInfo
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count "
      "FROM moz_places h "
      "WHERE h.url = ?1"),
    getter_AddRefs(mDBGetURLPageInfo));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBGetIdPageInfo
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count "
      "FROM moz_places h WHERE h.id = ?1"),
    getter_AddRefs(mDBGetIdPageInfo));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBRecentVisitOfURL
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT v.id, v.session "
      "FROM moz_places h JOIN moz_historyvisits v ON h.id = v.place_id "
      "WHERE h.url = ?1 "
      "ORDER BY v.visit_date DESC "
      "LIMIT 1"),
    getter_AddRefs(mDBRecentVisitOfURL));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBRecentVisitOfPlace
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT id "
      "FROM moz_historyvisits "
      "WHERE place_id = ?1 "
      "AND visit_date = ?2 "
      "AND session = ?3 "
      "LIMIT 1"),
    getter_AddRefs(mDBRecentVisitOfPlace));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBInsertVisit
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "INSERT INTO moz_historyvisits "
      "(from_visit, place_id, visit_date, visit_type, session) "
      "VALUES (?1, ?2, ?3, ?4, ?5)"),
    getter_AddRefs(mDBInsertVisit));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBGetPageVisitStats (see InternalAdd)
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT id, visit_count, typed, hidden "
      "FROM moz_places "
      "WHERE url = ?1"),
    getter_AddRefs(mDBGetPageVisitStats));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBIsPageVisited
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id FROM moz_places h WHERE h.url = ?1 " 
      "AND EXISTS "
      "(SELECT id FROM moz_historyvisits WHERE place_id = h.id LIMIT 1)"),
    getter_AddRefs(mDBIsPageVisited));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBUpdatePageVisitStats (see InternalAdd)
  // we don't need to update visit_count since it's maintained
  // in sync by triggers, and we must NEVER touch it
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "UPDATE moz_places "
      "SET hidden = ?2, typed = ?3 "
      "WHERE id = ?1"),
    getter_AddRefs(mDBUpdatePageVisitStats));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBAddNewPage (see InternalAddNewPage)
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "INSERT OR REPLACE INTO moz_places "
      "(url, title, rev_host, hidden, typed, frecency) "
      "VALUES (?1, ?2, ?3, ?4, ?5, ?6)"),
    getter_AddRefs(mDBAddNewPage));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBVisitToURLResult, should match kGetInfoIndex_* (see GetQueryResults)
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count, "
        SQL_STR_FRAGMENT_MAX_VISIT_DATE( "h.id" )
        ", f.url, null, null "
      "FROM moz_places h "
      "JOIN moz_historyvisits v ON h.id = v.place_id "
      "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
      "WHERE v.id = ?1"),
    getter_AddRefs(mDBVisitToURLResult));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBVisitToVisitResult, should match kGetInfoIndex_* (see GetQueryResults)
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count, "
             "v.visit_date, f.url, v.session, null "
      "FROM moz_places h "
      "JOIN moz_historyvisits v ON h.id = v.place_id "
      "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
      "WHERE v.id = ?1"),
    getter_AddRefs(mDBVisitToVisitResult));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBUrlToURLResult, should match kGetInfoIndex_*
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count, "
        SQL_STR_FRAGMENT_MAX_VISIT_DATE( "h.id" )
        ", f.url, null, null "
      "FROM moz_places h "
      "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
      "WHERE h.url = ?1"),
    getter_AddRefs(mDBUrlToUrlResult));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBBookmarkToUrlResult, should match kGetInfoIndex_*
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT b.fk, h.url, COALESCE(b.title, h.title), "
        "h.rev_host, h.visit_count, "
        SQL_STR_FRAGMENT_MAX_VISIT_DATE( "b.fk" )
        ", f.url, null, b.id, b.dateAdded, b.lastModified "
      "FROM moz_bookmarks b "
      "JOIN moz_places h ON b.fk = h.id "
      "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
      "WHERE b.id = ?1"),
    getter_AddRefs(mDBBookmarkToUrlResult));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBGetTags
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT GROUP_CONCAT(t.title, ' ') "
      "FROM moz_places h "
      "JOIN moz_bookmarks b ON b.type = ") +
        nsPrintfCString("%d", nsINavBookmarksService::TYPE_BOOKMARK) +
        NS_LITERAL_CSTRING(" AND b.fk = h.id "
      "JOIN moz_bookmarks t ON t.parent = ?1 AND t.id = b.parent "
      "WHERE h.url = ?2"),
    getter_AddRefs(mDBGetTags));
  NS_ENSURE_SUCCESS(rv, rv);

  // mFoldersWithAnnotationQuery
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT annos.item_id, annos.content FROM moz_anno_attributes attrs " 
    "JOIN moz_items_annos annos ON attrs.id = annos.anno_attribute_id "
    "WHERE attrs.name = ?1"), 
    getter_AddRefs(mFoldersWithAnnotationQuery));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBVisitsForFrecency
  // NOTE: we are not limiting to visits with "visit_type NOT IN (0,4,7)"
  // because if we do that, mDBVisitsForFrecency would return no visits
  // for places with only embed (or undefined) visits.  That would
  // cause use to estimate a frecency based on what information we do have,
  // see CalculateFrecencyInternal(). That would result in a non-zero frecency
  // for a place with only embedded visits, instead of a frecency of 0. If we
  // have a temporary or permanent redirect, calculate the frecency as if it
  // was the original page visited.
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT IFNULL(r.visit_date, v.visit_date) date, IFNULL(r.visit_type, v.visit_type) "
    "FROM moz_historyvisits v "
    "LEFT OUTER JOIN moz_historyvisits r "
      "ON r.id = v.from_visit AND v.visit_type IN ") +
      nsPrintfCString("(%d,%d) ", TRANSITION_REDIRECT_PERMANENT,
      TRANSITION_REDIRECT_TEMPORARY) + NS_LITERAL_CSTRING(
    "WHERE v.place_id = ?1 ORDER BY date DESC LIMIT ") +
     nsPrintfCString("%d", mNumVisitsForFrecency),
    getter_AddRefs(mDBVisitsForFrecency));
  NS_ENSURE_SUCCESS(rv, rv);

  // find places with invalid frecencies (frecency < 0)
  // invalid frecencies can happen in these scenarios:
  // 1) we've done "clear private data"
  // 2) we've expired or deleted visits
  // 3) we've migrated from an older version, before global frecency
  //
  // from older versions, unmigrated bookmarks might be hidden,
  // so we can't exclude hidden places (by doing "WHERE hidden <> 1")
  // from our query, as we want to calculate the frecency for those
  // places and unhide them (if they are not livemark items and not
  // place: queries.)
  //
  // Note, we are not limiting ourselves to places with visits
  // because we may not have any if the place is a bookmark and
  // we expired or deleted all the visits. 
  // We get two sets of places that are 1) most visited and 2) random so that
  // we don't get stuck recalculating frecencies that end up being -1 every
  // time
  // Notice that frecency is invalidated as frecency = -visit_count
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT * FROM "
      "(SELECT id, visit_count, hidden, typed, frecency, url "
      "FROM moz_places WHERE frecency < 0 "
      "ORDER BY frecency ASC LIMIT ROUND(?1 / 2)) "
    "UNION "
    "SELECT * FROM "
      "(SELECT id, visit_count, hidden, typed, frecency, url "
      "FROM moz_places WHERE frecency < 0 "
      "ORDER BY RANDOM() LIMIT ROUND(?1 / 2))"),
    getter_AddRefs(mDBInvalidFrecencies));
  NS_ENSURE_SUCCESS(rv, rv);

  // This query finds random old places to update frecency because frequently
  // visited places will have their frecencies updated when visited
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT id, visit_count, hidden, typed, frecency, url "
     "FROM moz_places "
     "ORDER BY RANDOM() LIMIT ?1"),
    getter_AddRefs(mDBOldFrecencies));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBUpdateFrecencyAndHidden
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "UPDATE moz_places SET frecency = ?2, hidden = ?3 WHERE id = ?1"),
    getter_AddRefs(mDBUpdateFrecencyAndHidden));
  NS_ENSURE_SUCCESS(rv, rv);

  // mDBGetPlaceVisitStats
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT typed, hidden, frecency FROM moz_places WHERE id = ?1"),
    getter_AddRefs(mDBGetPlaceVisitStats));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT b.parent FROM moz_places h JOIN moz_bookmarks b "
      " on b.fk = h.id WHERE b.type = 1 and h.id = ?1"),
    getter_AddRefs(mDBGetBookmarkParentsForPlace));
  NS_ENSURE_SUCCESS(rv, rv);

  // when calculating frecency, we want the visit count to be 
  // all the visits.
  rv = mDBConn->CreateStatement(
    NS_LITERAL_CSTRING("SELECT COUNT(*) FROM moz_historyvisits " 
      "WHERE place_id = ?1"),
    getter_AddRefs(mDBFullVisitCount));
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

// nsNavHistory::ForceMigrateBookmarksDB
//
//    This dumps all bookmarks-related tables, and recreates them,
//    forcing a re-import of bookmarks.html.
//
//    NOTE: This may cause data-loss if downgrading!
//    Only use this for migration if you're sure that bookmarks.html
//    and the target version support all bookmarks fields.
nsresult
nsNavHistory::ForceMigrateBookmarksDB(mozIStorageConnection* aDBConn) 
{
  // drop bookmarks tables
  nsresult rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("DROP TABLE IF EXISTS moz_bookmarks"));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("DROP TABLE IF EXISTS moz_bookmarks_folders"));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("DROP TABLE IF EXISTS moz_bookmarks_roots"));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("DROP TABLE IF EXISTS moz_keywords"));
  NS_ENSURE_SUCCESS(rv, rv);

  // initialize bookmarks tables
  rv = nsNavBookmarks::InitTables(aDBConn);
  NS_ENSURE_SUCCESS(rv, rv);

  // set pref indicating bookmarks.html should be imported.
  nsCOMPtr<nsIPrefBranch> prefs(do_GetService("@mozilla.org/preferences-service;1"));
  if (prefs) {
    prefs->SetBoolPref(PREF_BROWSER_IMPORT_BOOKMARKS, PR_TRUE);
  }
  return rv;
}

// nsNavHistory::MigrateV3Up
nsresult
nsNavHistory::MigrateV3Up(mozIStorageConnection* aDBConn) 
{
  // if type col is already there, then a partial update occurred.
  // return, making no changes, and allowing db version to be updated.
  nsCOMPtr<mozIStorageStatement> statement;
  nsresult rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING("SELECT type from moz_annos"),
                                         getter_AddRefs(statement));
  if (NS_SUCCEEDED(rv))
    return NS_OK;

  // add type column to moz_annos
  rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
    "ALTER TABLE moz_annos ADD type INTEGER DEFAULT 0"));
  if (NS_FAILED(rv)) {
    // if the alteration failed, force-migrate
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("DROP TABLE IF EXISTS moz_annos"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = nsAnnotationService::InitTables(mDBConn);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

// nsNavHistory::MigrateV6Up
nsresult
nsNavHistory::MigrateV6Up(mozIStorageConnection* aDBConn) 
{
  mozStorageTransaction transaction(aDBConn, PR_FALSE);

  // if dateAdded & lastModified cols are already there, then a partial update occurred,
  // and so we should not attempt to add these cols.
  nsCOMPtr<mozIStorageStatement> statement;
  nsresult rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT a.dateAdded, a.lastModified FROM moz_annos a"), 
    getter_AddRefs(statement));
  if (NS_FAILED(rv)) {
    // add dateAdded and lastModified columns to moz_annos
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "ALTER TABLE moz_annos ADD dateAdded INTEGER DEFAULT 0"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "ALTER TABLE moz_annos ADD lastModified INTEGER DEFAULT 0"));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // if dateAdded & lastModified cols are already there, then a partial update occurred,
  // and so we should not attempt to add these cols.  see bug #408443 for details.
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT b.dateAdded, b.lastModified FROM moz_items_annos b"), 
    getter_AddRefs(statement));
  if (NS_FAILED(rv)) {
    // add dateAdded and lastModified columns to moz_items_annos
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "ALTER TABLE moz_items_annos ADD dateAdded INTEGER DEFAULT 0"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "ALTER TABLE moz_items_annos ADD lastModified INTEGER DEFAULT 0"));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // we used to create an indexes on moz_favicons.url and
  // moz_anno_attributes.name, but those indexes are not needed
  // because those columns are UNIQUE, so remove them.
  // see bug #386303 for more details
  rv = aDBConn->ExecuteSimpleSQL(
    NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_favicons_url"));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = aDBConn->ExecuteSimpleSQL(
    NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_anno_attributes_nameindex"));
  NS_ENSURE_SUCCESS(rv, rv);

  return transaction.Commit();
}

// nsNavHistory::MigrateV7Up
nsresult
nsNavHistory::MigrateV7Up(mozIStorageConnection* aDBConn) 
{
  mozStorageTransaction transaction(aDBConn, PR_FALSE);

  // Create a statement to test for trigger creation
  nsCOMPtr<mozIStorageStatement> triggerDetection;
  nsresult rv = aDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT name "
    "FROM sqlite_master "
    "WHERE type = 'trigger' "
    "AND name = ?"
  ), getter_AddRefs(triggerDetection));
  NS_ENSURE_SUCCESS(rv, rv);

  // Check for existence
  PRBool triggerExists;
  rv = triggerDetection->BindUTF8StringParameter(
    0, NS_LITERAL_CSTRING("moz_historyvisits_afterinsert_v1_trigger")
  );
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->ExecuteStep(&triggerExists);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->Reset();
  NS_ENSURE_SUCCESS(rv, rv);

  // We need to create two triggers on moz_historyvists to maintain the
  // accuracy of moz_places.visit_count.  For this to work, we must ensure that
  // all moz_places.visit_count values are correct.
  // See bug 416313 for details.
  if (!triggerExists) {
    // First, we do a one-time reset of all the moz_places.visit_count values.
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "UPDATE moz_places SET visit_count = "
        "(SELECT count(*) FROM moz_historyvisits "
         "WHERE place_id = moz_places.id "
         "AND visit_type NOT IN (0, 4, 7))") /* invalid, EMBED, DOWNLOAD */
    );
    NS_ENSURE_SUCCESS(rv, rv);

    // Now we create our two triggers
    rv = aDBConn->ExecuteSimpleSQL(CREATE_VISIT_COUNT_INSERT_TRIGGER);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = aDBConn->ExecuteSimpleSQL(CREATE_VISIT_COUNT_DELETE_TRIGGER);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Check for existence
  rv = triggerDetection->BindUTF8StringParameter(
    0, NS_LITERAL_CSTRING("moz_bookmarks_beforedelete_v1_trigger")
  );
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->ExecuteStep(&triggerExists);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->Reset();
  NS_ENSURE_SUCCESS(rv, rv);

  // We need to create one trigger on moz_bookmarks to remove unused keywords.
  // See bug 421180 for details.
  if (!triggerExists) {
    // First, remove any existing dangling keywords
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DELETE FROM moz_keywords "
      "WHERE id IN ("
        "SELECT k.id "
        "FROM moz_keywords k "
        "LEFT OUTER JOIN moz_bookmarks b "
        "ON b.keyword_id = k.id "
        "WHERE b.id IS NULL"
      ")")
    );
    NS_ENSURE_SUCCESS(rv, rv);

    // Now we create our trigger
    rv = aDBConn->ExecuteSimpleSQL(CREATE_KEYWORD_VALIDITY_TRIGGER);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return transaction.Commit();
}

nsresult
nsNavHistory::EnsureCurrentSchema(mozIStorageConnection* aDBConn, PRBool* aDidMigrate)
{
  // We need an index on lastModified to catch quickly last modified bookmark
  // title for tag container's children. This will be useful for sync too.
  PRBool lastModIndexExists = PR_FALSE;
  nsresult rv = aDBConn->IndexExists(
    NS_LITERAL_CSTRING("moz_bookmarks_itemlastmodifiedindex"),
    &lastModIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!lastModIndexExists) {
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX moz_bookmarks_itemlastmodifiedindex "
        "ON moz_bookmarks (fk, lastModified)"));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // We need to do a one-time change of the moz_historyvisits.pageindex
  // to speed up finding last visit date when joinin with moz_places.
  // See bug 392399 for more details.
  PRBool oldIndexExists = PR_FALSE;
  rv = aDBConn->IndexExists(
    NS_LITERAL_CSTRING("moz_historyvisits_pageindex"), &oldIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (oldIndexExists) {
    *aDidMigrate = PR_TRUE;
    // wrap in a transaction for safety and performance
    mozStorageTransaction pageindexTransaction(aDBConn, PR_FALSE);

    // drop old index
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "DROP INDEX IF EXISTS moz_historyvisits_pageindex"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create the new multi-column index
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "CREATE INDEX IF NOT EXISTS moz_historyvisits_placedateindex "
        "ON moz_historyvisits (place_id, visit_date)"));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = pageindexTransaction.Commit();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // for existing profiles, we may not have a frecency column
  nsCOMPtr<mozIStorageStatement> statement;
  rv = aDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT frecency FROM moz_places"), getter_AddRefs(statement));

  if (NS_FAILED(rv)) {
    *aDidMigrate = PR_TRUE;
    // wrap in a transaction for safety and performance
    mozStorageTransaction frecencyTransaction(aDBConn, PR_FALSE);

    // add frecency column to moz_places, default to -1
    // so that all the frecencies are invalid and we'll
    // recalculate them on idle.
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "ALTER TABLE moz_places ADD frecency INTEGER DEFAULT -1 NOT NULL"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create index for the frecency column
    // XXX multi column index with typed, and visit_count?
    rv = aDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "CREATE INDEX IF NOT EXISTS "
      "moz_places_frecencyindex ON moz_places (frecency)"));
    NS_ENSURE_SUCCESS(rv, rv);

    // XXX todo
    // forcibly call the "on idle" timer here to do a little work
    // but the rest will happen on idle.

    // for place: items and unvisited livemark items, we need to set
    // the frecency to 0 so that they don't show up in url bar autocomplete
    rv = FixInvalidFrecenciesForExcludedPlaces();
    NS_ENSURE_SUCCESS(rv, rv);

    rv = frecencyTransaction.Commit();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}

nsresult
nsNavHistory::CleanUpOnQuit()
{
  // bug #371800 - remove moz_places.user_title
  // test for moz_places.user_title
  nsCOMPtr<mozIStorageStatement> statement2;
  nsresult rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT user_title FROM moz_places"), getter_AddRefs(statement2));
  if (NS_SUCCEEDED(rv)) {
    mozStorageTransaction transaction(mDBConn, PR_FALSE);
    // 1. Indexes are moved along with the renamed table. Since we're dropping
    // that table, we're also dropping it's indexes, and later re-creating them
    // for the new table.
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_urlindex"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_titleindex"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_faviconindex"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_hostindex"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_visitcount"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_frecencyindex"));
    NS_ENSURE_SUCCESS(rv, rv);

    // 2. remove any duplicate URIs
    rv = RemoveDuplicateURIs();
    NS_ENSURE_SUCCESS(rv, rv);

    // 3. rename moz_places to moz_places_backup
    rv = mDBConn->ExecuteSimpleSQL(
      NS_LITERAL_CSTRING("ALTER TABLE moz_places RENAME TO moz_places_backup"));
    NS_ENSURE_SUCCESS(rv, rv);

    // 4. create moz_places w/o user_title
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("CREATE TABLE moz_places ("
        "id INTEGER PRIMARY KEY, "
        "url LONGVARCHAR, "
        "title LONGVARCHAR, "
        "rev_host LONGVARCHAR, "
        "visit_count INTEGER DEFAULT 0, "
        "hidden INTEGER DEFAULT 0 NOT NULL, "
        "typed INTEGER DEFAULT 0 NOT NULL, "
        "favicon_id INTEGER, "
        "frecency INTEGER DEFAULT -1 NOT NULL)"));
    NS_ENSURE_SUCCESS(rv, rv);

    // 5. recreate the indexes
    // NOTE: tests showed that it's faster to create the indexes prior to filling
    // the table than it is to add them afterwards.
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("CREATE UNIQUE INDEX moz_places_url_uniqueindex ON moz_places (url)"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("CREATE INDEX moz_places_faviconindex ON moz_places (favicon_id)"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("CREATE INDEX moz_places_hostindex ON moz_places (rev_host)"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("CREATE INDEX moz_places_visitcount ON moz_places (visit_count)"));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("CREATE INDEX moz_places_frecencyindex ON moz_places (frecency)"));
    NS_ENSURE_SUCCESS(rv, rv);

    // 6. copy all data into moz_places
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "INSERT INTO moz_places "
      "SELECT id, url, title, rev_host, visit_count, hidden, typed, favicon_id, frecency "
      "FROM moz_places_backup"));
    NS_ENSURE_SUCCESS(rv, rv);

    // 7. drop moz_places_backup
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DROP TABLE moz_places_backup"));
    NS_ENSURE_SUCCESS(rv, rv);
    transaction.Commit();
  }

  // bug #381795 - remove unused indexes
  mozStorageTransaction idxTransaction(mDBConn, PR_FALSE);
  rv = mDBConn->ExecuteSimpleSQL(
    NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_titleindex"));
  rv = mDBConn->ExecuteSimpleSQL(
    NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_annos_item_idindex"));
  idxTransaction.Commit();

  // Do a one-time re-creation of the moz_annos indexes (bug 415201)
  PRBool oldIndexExists = PR_FALSE;
  rv = mDBConn->IndexExists(NS_LITERAL_CSTRING("moz_annos_attributesindex"), &oldIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);
  if (oldIndexExists) {
    // wrap in a transaction for safety and performance
    mozStorageTransaction annoIndexTransaction(mDBConn, PR_FALSE);

    // drop old uri annos index
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX moz_annos_attributesindex"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create new uri annos index
    rv = mDBConn->ExecuteSimpleSQL(
      NS_LITERAL_CSTRING("CREATE UNIQUE INDEX moz_annos_placeattributeindex ON moz_annos (place_id, anno_attribute_id)"));
    NS_ENSURE_SUCCESS(rv, rv);

    // drop old item annos index
    rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_items_annos_attributesindex"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create new item annos index
    rv = mDBConn->ExecuteSimpleSQL(
      NS_LITERAL_CSTRING("CREATE UNIQUE INDEX moz_items_annos_itemattributeindex ON moz_items_annos (item_id, anno_attribute_id)"));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = annoIndexTransaction.Commit();
    NS_ENSURE_SUCCESS(rv, rv);
  }
  return NS_OK;
}


// nsNavHistory::GetUrlIdFor
//
//    Called by the bookmarks and annotation services, this function returns the
//    ID of the row for the given URL, optionally creating one if it doesn't
//    exist. A newly created entry will have no visits.
//
//    If aAutoCreate is false and the item doesn't exist, the entry ID will be
//    zero.
//
//    This DOES NOT check for bad URLs other than that they're nonempty.

nsresult
nsNavHistory::GetUrlIdFor(nsIURI* aURI, PRInt64* aEntryID,
                          PRBool aAutoCreate)
{
  *aEntryID = 0;

  mozStorageStatementScoper statementResetter(mDBGetURLPageInfo);
  nsresult rv = BindStatementURI(mDBGetURLPageInfo, 0, aURI);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasEntry = PR_FALSE;
  rv = mDBGetURLPageInfo->ExecuteStep(&hasEntry);
  NS_ENSURE_SUCCESS(rv, rv);

  if (hasEntry) {
    return mDBGetURLPageInfo->GetInt64(kGetInfoIndex_PageID, aEntryID);
  } else if (aAutoCreate) {
    // create a new hidden, untyped, unvisited entry
    mDBGetURLPageInfo->Reset();
    statementResetter.Abandon();
    nsString voidString;
    voidString.SetIsVoid(PR_TRUE);
    return InternalAddNewPage(aURI, voidString, PR_TRUE, PR_FALSE, 0, PR_TRUE, aEntryID);
  } else {
    // Doesn't exist: don't do anything, entry ID was already set to 0 above
    return NS_OK;
  }
}


// nsNavHistory::InternalAddNewPage
//
//    Adds a new page to the DB.
//    THIS SHOULD BE THE ONLY PLACE NEW moz_places ROWS ARE
//    CREATED. This allows us to maintain better consistency.
//
//    If non-null, the new page ID will be placed into aPageID.

nsresult
nsNavHistory::InternalAddNewPage(nsIURI* aURI,
                                 const nsAString& aTitle,
                                 PRBool aHidden,
                                 PRBool aTyped,
                                 PRInt32 aVisitCount,
                                 PRBool aCalculateFrecency,
                                 PRInt64* aPageID)
{
  mozStorageStatementScoper scoper(mDBAddNewPage);
  nsresult rv = BindStatementURI(mDBAddNewPage, 0, aURI);
  NS_ENSURE_SUCCESS(rv, rv);

  // title
  if (aTitle.IsVoid()) {
    // if no title is specified, make up a title based on the filename
    nsAutoString title;
    GenerateTitleFromURI(aURI, title);
    rv = mDBAddNewPage->BindStringParameter(1,
        StringHead(title, HISTORY_TITLE_LENGTH_MAX));
  } else {
    rv = mDBAddNewPage->BindStringParameter(1,
        StringHead(aTitle, HISTORY_TITLE_LENGTH_MAX));
  }
  NS_ENSURE_SUCCESS(rv, rv);

  // host (reversed with trailing period)
  nsAutoString revHost;
  rv = GetReversedHostname(aURI, revHost);
  // Not all URI types have hostnames, so this is optional.
  if (NS_SUCCEEDED(rv)) {
    rv = mDBAddNewPage->BindStringParameter(2, revHost);
  } else {
    rv = mDBAddNewPage->BindNullParameter(2);
  }
  NS_ENSURE_SUCCESS(rv, rv);

  // hidden
  rv = mDBAddNewPage->BindInt32Parameter(3, aHidden);
  NS_ENSURE_SUCCESS(rv, rv);

  // typed
  rv = mDBAddNewPage->BindInt32Parameter(4, aTyped);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCAutoString url;
  rv = aURI->GetSpec(url);
  NS_ENSURE_SUCCESS(rv, rv);

  // frecency
  PRInt32 frecency = -1;
  if (aCalculateFrecency) {
    rv = CalculateFrecency(-1 /* no page id, since this page doesn't exist */,
                           aTyped, aVisitCount, url, &frecency);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  rv = mDBAddNewPage->BindInt32Parameter(5, frecency);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mDBAddNewPage->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  // If the caller wants the page ID, go get it
  if (aPageID) {
    mozStorageStatementScoper scoper(mDBGetURLPageInfo);

    rv = BindStatementURI(mDBGetURLPageInfo, 0, aURI);
    NS_ENSURE_SUCCESS(rv, rv);

    PRBool hasResult = PR_FALSE;
    rv = mDBGetURLPageInfo->ExecuteStep(&hasResult);
    NS_ENSURE_SUCCESS(rv, rv);
    NS_ASSERTION(hasResult, "hasResult is false but the call succeeded?");

    *aPageID = mDBGetURLPageInfo->AsInt64(0);
  }

  return NS_OK;
}

// nsNavHistory::InternalAddVisit
//
//    Just a wrapper for inserting a new visit in the DB.

nsresult
nsNavHistory::InternalAddVisit(PRInt64 aPageID, PRInt64 aReferringVisit,
                               PRInt64 aSessionID, PRTime aTime,
                               PRInt32 aTransitionType, PRInt64* visitID)
{
  nsresult rv;

  {
    mozStorageStatementScoper scoper(mDBInsertVisit);
  
    rv = mDBInsertVisit->BindInt64Parameter(0, aReferringVisit);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBInsertVisit->BindInt64Parameter(1, aPageID);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBInsertVisit->BindInt64Parameter(2, aTime);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBInsertVisit->BindInt32Parameter(3, aTransitionType);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBInsertVisit->BindInt64Parameter(4, aSessionID);
    NS_ENSURE_SUCCESS(rv, rv);
  
    rv = mDBInsertVisit->Execute();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  {
    mozStorageStatementScoper scoper(mDBRecentVisitOfPlace);

    rv = mDBRecentVisitOfPlace->BindInt64Parameter(0, aPageID);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBRecentVisitOfPlace->BindInt64Parameter(1, aTime);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBRecentVisitOfPlace->BindInt64Parameter(2, aSessionID);
    NS_ENSURE_SUCCESS(rv, rv);

    PRBool hasResult;
    rv = mDBRecentVisitOfPlace->ExecuteStep(&hasResult);
    NS_ENSURE_SUCCESS(rv, rv);
    NS_ASSERTION(hasResult, "hasResult is false but the call succeeded?");

    *visitID = mDBRecentVisitOfPlace->AsInt64(0);
  }
  return NS_OK;
}


// nsNavHistory::FindLastVisit
//
//    This finds the most recent visit to the given URL. If found, it will put
//    that visit's ID and session into the respective out parameters and return
//    true. Returns false if no visit is found.
//
//    This is used to compute the referring visit.

PRBool
nsNavHistory::FindLastVisit(nsIURI* aURI, PRInt64* aVisitID,
                            PRInt64* aSessionID)
{
  mozStorageStatementScoper scoper(mDBRecentVisitOfURL);
  nsresult rv = BindStatementURI(mDBRecentVisitOfURL, 0, aURI);
  NS_ENSURE_SUCCESS(rv, PR_FALSE);

  PRBool hasMore;
  rv = mDBRecentVisitOfURL->ExecuteStep(&hasMore);
  NS_ENSURE_SUCCESS(rv, PR_FALSE);
  if (hasMore) {
    *aVisitID = mDBRecentVisitOfURL->AsInt64(0);
    *aSessionID = mDBRecentVisitOfURL->AsInt64(1);
    return PR_TRUE;
  }
  return PR_FALSE;
}


// nsNavHistory::IsURIStringVisited
//
//    Takes a URL as a string and returns true if we've visited it.
//
//    Be careful to always reset the statement since it will be reused.

PRBool nsNavHistory::IsURIStringVisited(const nsACString& aURIString)
{
#ifdef LAZY_ADD
  // check the lazy list to see if this has recently been added
  for (PRUint32 i = 0; i < mLazyMessages.Length(); i ++) {
    if (mLazyMessages[i].type == LazyMessage::Type_AddURI) {
      if (aURIString.Equals(mLazyMessages[i].uriSpec))
        return PR_TRUE;
    }
  }
#endif

  // check the main DB
  mozStorageStatementScoper scoper(mDBIsPageVisited);
  nsresult rv = mDBIsPageVisited->BindUTF8StringParameter(0, aURIString);
  NS_ENSURE_SUCCESS(rv, PR_FALSE);

  PRBool hasMore = PR_FALSE;
  rv = mDBIsPageVisited->ExecuteStep(&hasMore);
  NS_ENSURE_SUCCESS(rv, PR_FALSE);
  return hasMore;
}


// nsNavHistory::LoadPrefs

nsresult
nsNavHistory::LoadPrefs(PRBool aInitializing)
{
  if (! mPrefBranch)
    return NS_OK;

  mPrefBranch->GetIntPref(PREF_BROWSER_HISTORY_EXPIRE_DAYS_MAX, &mExpireDaysMax);
  mPrefBranch->GetIntPref(PREF_BROWSER_HISTORY_EXPIRE_DAYS_MIN, &mExpireDaysMin);
  // Cap max days to min days to prevent expiring pages younger than min
  // NOTE: if history is disabled in preferences, then mExpireDaysMax == 0
  if (mExpireDaysMax && mExpireDaysMax < mExpireDaysMin)
    mExpireDaysMax = mExpireDaysMin;
  if (NS_FAILED(mPrefBranch->GetIntPref(PREF_BROWSER_HISTORY_EXPIRE_SITES,
                                        &mExpireSites)))
    mExpireSites = EXPIRATION_CAP_SITES;
  
#ifdef MOZ_XUL
  PRBool oldCompleteOnlyTyped = mAutoCompleteOnlyTyped;
  mPrefBranch->GetBoolPref(PREF_AUTOCOMPLETE_ONLY_TYPED,
                           &mAutoCompleteOnlyTyped);

  PRInt32 matchBehavior;
  mPrefBranch->GetIntPref(PREF_AUTOCOMPLETE_MATCH_BEHAVIOR,
                          &matchBehavior);
  switch (matchBehavior) {
    case 0:
      mAutoCompleteMatchBehavior = MATCH_ANYWHERE;
      break;
    case 2:
      mAutoCompleteMatchBehavior = MATCH_BOUNDARY;
      break;
    default:
      mAutoCompleteMatchBehavior = MATCH_BOUNDARY_ANYWHERE;
      break;
  }

  mPrefBranch->GetBoolPref(PREF_AUTOCOMPLETE_FILTER_JAVASCRIPT,
                           &mAutoCompleteFilterJavascript);
  mPrefBranch->GetIntPref(PREF_AUTOCOMPLETE_MAX_RICH_RESULTS,
                          &mAutoCompleteMaxResults);
  mPrefBranch->GetIntPref(PREF_AUTOCOMPLETE_SEARCH_CHUNK_SIZE,
                          &mAutoCompleteSearchChunkSize);
  mPrefBranch->GetIntPref(PREF_AUTOCOMPLETE_SEARCH_TIMEOUT,
                          &mAutoCompleteSearchTimeout);
  nsXPIDLCString prefStr;
  mPrefBranch->GetCharPref(PREF_AUTOCOMPLETE_RESTRICT_HISTORY,
                           getter_Copies(prefStr));
  mAutoCompleteRestrictHistory = NS_ConvertUTF8toUTF16(prefStr);
  mPrefBranch->GetCharPref(PREF_AUTOCOMPLETE_RESTRICT_BOOKMARK,
                           getter_Copies(prefStr));
  mAutoCompleteRestrictBookmark = NS_ConvertUTF8toUTF16(prefStr);
  mPrefBranch->GetCharPref(PREF_AUTOCOMPLETE_RESTRICT_TAG,
                           getter_Copies(prefStr));
  mAutoCompleteRestrictTag = NS_ConvertUTF8toUTF16(prefStr);
  mPrefBranch->GetCharPref(PREF_AUTOCOMPLETE_MATCH_TITLE,
                           getter_Copies(prefStr));
  mAutoCompleteMatchTitle = NS_ConvertUTF8toUTF16(prefStr);
  mPrefBranch->GetCharPref(PREF_AUTOCOMPLETE_MATCH_URL,
                           getter_Copies(prefStr));
  mAutoCompleteMatchUrl = NS_ConvertUTF8toUTF16(prefStr);

  if (!aInitializing && oldCompleteOnlyTyped != mAutoCompleteOnlyTyped) {
    // update the autocomplete statements if the option has changed.
    nsresult rv = CreateAutoCompleteQueries();
    NS_ENSURE_SUCCESS(rv, rv);
  }
#endif

  // get the frecency prefs
  nsCOMPtr<nsIPrefBranch> prefs(do_GetService("@mozilla.org/preferences-service;1"));
  if (prefs) {
    prefs->GetIntPref(PREF_FRECENCY_NUM_VISITS, 
      &mNumVisitsForFrecency);
    prefs->GetIntPref(PREF_FRECENCY_CALC_ON_IDLE, 
      &mNumCalculateFrecencyOnIdle);
    prefs->GetIntPref(PREF_FRECENCY_CALC_ON_MIGRATE, 
      &mNumCalculateFrecencyOnMigrate);
    prefs->GetIntPref(PREF_FRECENCY_UPDATE_IDLE_TIME, 
      &mFrecencyUpdateIdleTime);
    prefs->GetIntPref(PREF_FRECENCY_FIRST_BUCKET_CUTOFF, 
      &mFirstBucketCutoffInDays);
    prefs->GetIntPref(PREF_FRECENCY_SECOND_BUCKET_CUTOFF,
      &mSecondBucketCutoffInDays);
    prefs->GetIntPref(PREF_FRECENCY_THIRD_BUCKET_CUTOFF, 
      &mThirdBucketCutoffInDays);
    prefs->GetIntPref(PREF_FRECENCY_FOURTH_BUCKET_CUTOFF, 
      &mFourthBucketCutoffInDays);
    prefs->GetIntPref(PREF_FRECENCY_EMBED_VISIT_BONUS, 
      &mEmbedVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_LINK_VISIT_BONUS, 
      &mLinkVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_TYPED_VISIT_BONUS, 
      &mTypedVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_BOOKMARK_VISIT_BONUS, 
      &mBookmarkVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_DOWNLOAD_VISIT_BONUS, 
      &mDownloadVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_PERM_REDIRECT_VISIT_BONUS, 
      &mPermRedirectVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_TEMP_REDIRECT_VISIT_BONUS, 
      &mTempRedirectVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_DEFAULT_VISIT_BONUS, 
      &mDefaultVisitBonus);
    prefs->GetIntPref(PREF_FRECENCY_UNVISITED_BOOKMARK_BONUS, 
      &mUnvisitedBookmarkBonus);
    prefs->GetIntPref(PREF_FRECENCY_UNVISITED_TYPED_BONUS,
      &mUnvisitedTypedBonus);
    prefs->GetIntPref(PREF_FRECENCY_FIRST_BUCKET_WEIGHT, 
      &mFirstBucketWeight);
    prefs->GetIntPref(PREF_FRECENCY_SECOND_BUCKET_WEIGHT, 
      &mSecondBucketWeight);
    prefs->GetIntPref(PREF_FRECENCY_THIRD_BUCKET_WEIGHT, 
      &mThirdBucketWeight);
    prefs->GetIntPref(PREF_FRECENCY_FOURTH_BUCKET_WEIGHT, 
      &mFourthBucketWeight);
    prefs->GetIntPref(PREF_FRECENCY_DEFAULT_BUCKET_WEIGHT, 
      &mDefaultWeight);
  }
  return NS_OK;
}


// nsNavHistory::GetNow
//
//    This is a hack to avoid calling PR_Now() too often, as is the case when
//    we're asked the ageindays of many history entries in a row. A timer is
//    set which will clear our valid flag after a short timeout.

PRTime
nsNavHistory::GetNow()
{
  if (!mNowValid) {
    mLastNow = PR_Now();
    mNowValid = PR_TRUE;
    if (!mExpireNowTimer)
      mExpireNowTimer = do_CreateInstance("@mozilla.org/timer;1");

    if (mExpireNowTimer)
      mExpireNowTimer->InitWithFuncCallback(expireNowTimerCallback, this,
                                            HISTORY_EXPIRE_NOW_TIMEOUT,
                                            nsITimer::TYPE_ONE_SHOT);
  }

  return mLastNow;
}


// nsNavHistory::expireNowTimerCallback

void nsNavHistory::expireNowTimerCallback(nsITimer* aTimer, void* aClosure)
{
  nsNavHistory* history = static_cast<nsNavHistory*>(aClosure);
  history->mNowValid = PR_FALSE;
  history->mExpireNowTimer = nsnull;
}

static PRTime
NormalizeTimeRelativeToday(PRTime aTime)
{
  // round to midnight this morning
  PRExplodedTime explodedTime;
  PR_ExplodeTime(aTime, PR_LocalTimeParameters, &explodedTime);

  // set to midnight (0:00)
  explodedTime.tm_min =
    explodedTime.tm_hour =
    explodedTime.tm_sec =
    explodedTime.tm_usec = 0;

  return PR_ImplodeTime(&explodedTime);
}

// nsNavHistory::NormalizeTime
//
//    Converts a nsINavHistoryQuery reference+offset time into a PRTime
//    relative to the epoch.
//
//    It is important that this function NOT use the current time optimization.
//    It is called to update queries, and we really need to know what right
//    now is because those incoming values will also have current times that
//    we will have to compare against.

PRTime // static
nsNavHistory::NormalizeTime(PRUint32 aRelative, PRTime aOffset)
{
  PRTime ref;
  switch (aRelative)
  {
    case nsINavHistoryQuery::TIME_RELATIVE_EPOCH:
      return aOffset;
    case nsINavHistoryQuery::TIME_RELATIVE_TODAY:
      ref = NormalizeTimeRelativeToday(PR_Now());
      break;
    case nsINavHistoryQuery::TIME_RELATIVE_NOW:
      ref = PR_Now();
      break;
    default:
      NS_NOTREACHED("Invalid relative time");
      return 0;
  }
  return ref + aOffset;
}

// nsNavHistory::GetUpdateRequirements
//
//    Returns conditions for query update.
//
//    QUERYUPDATE_TIME:
//      This query is only limited by an inclusive time range on the first
//      query object. The caller can quickly evaluate the time itself if it
//      chooses. This is even simpler than "simple" below.
//    QUERYUPDATE_SIMPLE:
//      This query is evaluatable using EvaluateQueryForNode to do live
//      updating.
//    QUERYUPDATE_COMPLEX:
//      This query is not evaluatable using EvaluateQueryForNode. When something
//      happens that this query updates, you will need to re-run the query.
//    QUERYUPDATE_COMPLEX_WITH_BOOKMARKS:
//      A complex query that additionally has dependence on bookmarks. All
//      bookmark-dependent queries fall under this category.
//
//    aHasSearchTerms will be set to true if the query has any dependence on
//    keywords. When there is no dependence on keywords, we can handle title
//    change operations as simple instead of complex.

PRUint32
nsNavHistory::GetUpdateRequirements(const nsCOMArray<nsNavHistoryQuery>& aQueries,
                                    nsNavHistoryQueryOptions* aOptions,
                                    PRBool* aHasSearchTerms)
{
  NS_ASSERTION(aQueries.Count() > 0, "Must have at least one query");

  // first check if there are search terms
  *aHasSearchTerms = PR_FALSE;
  PRInt32 i;
  for (i = 0; i < aQueries.Count(); i ++) {
    aQueries[i]->GetHasSearchTerms(aHasSearchTerms);
    if (*aHasSearchTerms)
      break;
  }

  PRBool nonTimeBasedItems = PR_FALSE;
  PRBool domainBasedItems = PR_FALSE;

  for (i = 0; i < aQueries.Count(); i ++) {
    nsNavHistoryQuery* query = aQueries[i];

    if (query->Folders().Length() > 0 || query->OnlyBookmarked()) {
      return QUERYUPDATE_COMPLEX_WITH_BOOKMARKS;
    }
    // Note: we don't currently have any complex non-bookmarked items, but these
    // are expected to be added. Put detection of these items here.
    if (! query->SearchTerms().IsEmpty() ||
        ! query->Domain().IsVoid() ||
        query->Uri() != nsnull)
      nonTimeBasedItems = PR_TRUE;

    if (! query->Domain().IsVoid())
      domainBasedItems = PR_TRUE;
  }

  if (aOptions->ResultType() ==
      nsINavHistoryQueryOptions::RESULTS_AS_TAG_QUERY)
    return QUERYUPDATE_COMPLEX_WITH_BOOKMARKS;

  // Whenever there is a maximum number of results, 
  // and we are not a bookmark query we must requery. This
  // is because we can't generally know if any given addition/change causes
  // the item to be in the top N items in the database.
  if (aOptions->MaxResults() > 0)
    return QUERYUPDATE_COMPLEX;

  if (aQueries.Count() == 1 && domainBasedItems)
    return QUERYUPDATE_HOST;
  if (aQueries.Count() == 1 && ! nonTimeBasedItems)
    return QUERYUPDATE_TIME;
  return QUERYUPDATE_SIMPLE;
}


// nsNavHistory::EvaluateQueryForNode
//
//    This runs the node through the given queries to see if satisfies the
//    query conditions. Not every query parameters are handled by this code,
//    but we handle the most common ones so that performance is better.
//
//    We assume that the time on the node is the time that we want to compare.
//    This is not necessarily true because URL nodes have the last access time,
//    which is not necessarily the same. However, since this is being called
//    to update the list, we assume that the last access time is the current
//    access time that we are being asked to compare so it works out.
//
//    Returns true if node matches the query, false if not.

PRBool
nsNavHistory::EvaluateQueryForNode(const nsCOMArray<nsNavHistoryQuery>& aQueries,
                                   nsNavHistoryQueryOptions* aOptions,
                                   nsNavHistoryResultNode* aNode)
{
  // lazily created from the node's string when we need to match URIs
  nsCOMPtr<nsIURI> nodeUri;

  for (PRInt32 i = 0; i < aQueries.Count(); i ++) {
    PRBool hasIt;
    nsCOMPtr<nsNavHistoryQuery> query = aQueries[i];

    // --- begin time ---
    query->GetHasBeginTime(&hasIt);
    if (hasIt) {
      PRTime beginTime = NormalizeTime(query->BeginTimeReference(),
                                       query->BeginTime());
      if (aNode->mTime < beginTime)
        continue; // before our time range
    }

    // --- end time ---
    query->GetHasEndTime(&hasIt);
    if (hasIt) {
      PRTime endTime = NormalizeTime(query->EndTimeReference(),
                                     query->EndTime());
      if (aNode->mTime > endTime)
        continue; // after our time range
    }

    // --- search terms ---
    if (! query->SearchTerms().IsEmpty()) {
      // we can use the existing filtering code, just give it our one object in
      // an array.
      nsCOMArray<nsNavHistoryResultNode> inputSet;
      inputSet.AppendObject(aNode);
      nsCOMArray<nsNavHistoryQuery> queries;
      queries.AppendObject(query);
      nsCOMArray<nsNavHistoryResultNode> filteredSet;
      nsresult rv = FilterResultSet(nsnull, inputSet, &filteredSet, queries, aOptions);
      if (NS_FAILED(rv))
        continue;
      if (! filteredSet.Count())
        continue; // did not make it through the filter, doesn't match
    }

    // --- domain/host matching ---
    query->GetHasDomain(&hasIt);
    if (hasIt) {
      if (! nodeUri) {
        // lazy creation of nodeUri, which might be checked for multiple queries
        if (NS_FAILED(NS_NewURI(getter_AddRefs(nodeUri), aNode->mURI)))
          continue;
      }
      nsCAutoString asciiRequest;
      if (NS_FAILED(AsciiHostNameFromHostString(query->Domain(), asciiRequest)))
        continue;

      if (query->DomainIsHost()) {
        nsCAutoString host;
        if (NS_FAILED(nodeUri->GetAsciiHost(host)))
          continue;

        if (! asciiRequest.Equals(host))
          continue; // host names don't match
      }
      // check domain names
      nsCAutoString domain;
      DomainNameFromURI(nodeUri, domain);
      if (! asciiRequest.Equals(domain))
        continue; // domain names don't match
    }

    // --- URI matching ---
    if (query->Uri()) {
      if (! nodeUri) { // lazy creation of nodeUri
        if (NS_FAILED(NS_NewURI(getter_AddRefs(nodeUri), aNode->mURI)))
          continue;
      }
      if (! query->UriIsPrefix()) {
        // easy case: the URI is an exact match
        PRBool equals;
        nsresult rv = query->Uri()->Equals(nodeUri, &equals);
        NS_ENSURE_SUCCESS(rv, PR_FALSE);
        if (! equals)
          continue;
      } else {
        // harder case: match prefix, note that we need to get the ASCII string
        // from the node's parsed URI instead of using the node's mUrl string,
        // because that might not be normalized
        nsCAutoString nodeUriString;
        nodeUri->GetAsciiSpec(nodeUriString);
        nsCAutoString queryUriString;
        query->Uri()->GetAsciiSpec(queryUriString);
        if (queryUriString.Length() > nodeUriString.Length())
          continue; // not long enough to match as prefix
        nodeUriString.SetLength(queryUriString.Length());
        if (! nodeUriString.Equals(queryUriString))
          continue; // prefixes don't match
      }
    }

    // If we ever make it to the bottom of this loop, that means it passed all
    // tests for the given query. Since queries are ORed together, that means
    // it passed everything and we are done.
    return PR_TRUE;
  }

  // didn't match any query
  return PR_FALSE;
}


// nsNavHistory::AsciiHostNameFromHostString
//
//    We might have interesting encodings and different case in the host name.
//    This will convert that host name into an ASCII host name by sending it
//    through the URI canonicalization. The result can be used for comparison
//    with other ASCII host name strings.

nsresult // static
nsNavHistory::AsciiHostNameFromHostString(const nsACString& aHostName,
                                          nsACString& aAscii)
{
  nsCOMPtr<nsIURI> uri;
  nsresult rv = NS_NewURI(getter_AddRefs(uri), aHostName);
  NS_ENSURE_SUCCESS(rv, rv);
  return uri->GetAsciiHost(aAscii);
}


// nsNavHistory::DomainNameFromURI
//
//    This does the www.mozilla.org -> mozilla.org and
//    foo.theregister.co.uk -> theregister.co.uk conversion

void
nsNavHistory::DomainNameFromURI(nsIURI *aURI,
                                nsACString& aDomainName)
{
  // lazily get the effective tld service
  if (!mTLDService)
    mTLDService = do_GetService(NS_EFFECTIVETLDSERVICE_CONTRACTID);

  if (mTLDService) {
    // get the base domain for a given hostname.
    // e.g. for "images.bbc.co.uk", this would be "bbc.co.uk".
    nsresult rv = mTLDService->GetBaseDomain(aURI, 0, aDomainName);
    if (NS_SUCCEEDED(rv))
      return;
  }

  // just return the original hostname
  // (it's also possible the host is an IP address)
  aURI->GetAsciiHost(aDomainName);
}


// Nav history *****************************************************************


// nsNavHistory::GetHasHistoryEntries

NS_IMETHODIMP
nsNavHistory::GetHasHistoryEntries(PRBool* aHasEntries)
{
  nsCOMPtr<mozIStorageStatement> dbSelectStatement;
  nsresult rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING("SELECT id FROM moz_historyvisits LIMIT 1"),
      getter_AddRefs(dbSelectStatement));
  NS_ENSURE_SUCCESS(rv, rv);
  return dbSelectStatement->ExecuteStep(aHasEntries);
}

nsresult
nsNavHistory::FixInvalidFrecenciesForExcludedPlaces()
{
  // for every moz_place that has an invalid frecency (< 0) and
  // is an unvisited child of a livemark feed, or begins with "place:",
  // set frecency to 0 so that it is excluded from url bar autocomplete.
  nsCOMPtr<mozIStorageStatement> dbUpdateStatement;
  nsresult rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
    "UPDATE moz_places "
    "SET frecency = 0 WHERE id IN ("
      "SELECT h.id FROM moz_places h "
      "LEFT OUTER JOIN moz_bookmarks b ON h.id = b.fk "
      "WHERE frecency < 0 AND "
        // place is an unvisited child of a livemark feed
        "(b.parent IN ("
            "SELECT annos.item_id FROM moz_anno_attributes attrs "
            "JOIN moz_items_annos annos ON attrs.id = annos.anno_attribute_id "
            "WHERE attrs.name = ?1) "
          "AND visit_count = 0) "
        "OR SUBSTR(h.url,0,6) = 'place:')"),
    getter_AddRefs(dbUpdateStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = dbUpdateStatement->BindUTF8StringParameter(0, NS_LITERAL_CSTRING(LMANNO_FEEDURI));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = dbUpdateStatement->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
nsNavHistory::CalculateFullVisitCount(PRInt64 aPlaceId, PRInt32 *aVisitCount)
{
  mozStorageStatementScoper scope(mDBFullVisitCount);

  nsresult rv = mDBFullVisitCount->BindInt64Parameter(0, aPlaceId);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasVisits = PR_TRUE;
  rv = mDBFullVisitCount->ExecuteStep(&hasVisits);
  NS_ENSURE_SUCCESS(rv, rv);

  if (hasVisits) {
    rv = mDBFullVisitCount->GetInt32(0, aVisitCount);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  else
    *aVisitCount = 0;
  
  return NS_OK;
}

// nsNavHistory::MarkPageAsFollowedBookmark
//
// We call MarkPageAsFollowedBookmark() before visiting a URL in order to 
// help determine the transition type of the visit.  
// We keep track of the URL so that later, in AddVisitChain() 
// we can use TRANSITION_BOOKMARK as the transition.
// Note, AddVisitChain() is not called immediately when we are doing LAZY_ADDs
//
// @see MarkPageAsTyped

NS_IMETHODIMP
nsNavHistory::MarkPageAsFollowedBookmark(nsIURI* aURI)
{
  // don't add when history is disabled
  if (IsHistoryDisabled())
    return NS_OK;

  nsCAutoString uriString;
  nsresult rv = aURI->GetSpec(uriString);
  NS_ENSURE_SUCCESS(rv, rv);

  // if URL is already in the bookmark queue, then we need to remove the old one
  PRInt64 unusedEventTime;
  if (mRecentBookmark.Get(uriString, &unusedEventTime))
    mRecentBookmark.Remove(uriString);

  if (mRecentBookmark.Count() > RECENT_EVENT_QUEUE_MAX_LENGTH)
    ExpireNonrecentEvents(&mRecentBookmark);

  mRecentBookmark.Put(uriString, GetNow());
  return NS_OK;
}


// nsNavHistory::CanAddURI
//
//    Filter out unwanted URIs such as "chrome:", "mailbox:", etc.
//
//    The model is if we don't know differently then add which basically means
//    we are suppose to try all the things we know not to allow in and then if
//    we don't bail go on and allow it in.

NS_IMETHODIMP
nsNavHistory::CanAddURI(nsIURI* aURI, PRBool* canAdd)
{
  NS_ENSURE_ARG_POINTER(aURI);

  nsCAutoString scheme;
  nsresult rv = aURI->GetScheme(scheme);
  NS_ENSURE_SUCCESS(rv, rv);

  // first check the most common cases (HTTP, HTTPS) to allow in to avoid most
  // of the work
  if (scheme.EqualsLiteral("http")) {
    *canAdd = PR_TRUE;
    return NS_OK;
  }
  if (scheme.EqualsLiteral("https")) {
    *canAdd = PR_TRUE;
    return NS_OK;
  }

  // now check for all bad things
  if (scheme.EqualsLiteral("about") ||
      scheme.EqualsLiteral("imap") ||
      scheme.EqualsLiteral("news") ||
      scheme.EqualsLiteral("mailbox") ||
      scheme.EqualsLiteral("moz-anno") ||
      scheme.EqualsLiteral("view-source") ||
      scheme.EqualsLiteral("chrome") ||
      scheme.EqualsLiteral("data")) {
    *canAdd = PR_FALSE;
    return NS_OK;
  }
  *canAdd = PR_TRUE;
  return NS_OK;
}

// nsNavHistory::AddVisit
//
//    Adds or updates a page with the given URI. The ID of the new visit will
//    be put into aVisitID.
//
//    THE RETURNED NEW VISIT ID MAY BE 0 indicating that this page should not be
//    added to the history.

NS_IMETHODIMP
nsNavHistory::AddVisit(nsIURI* aURI, PRTime aTime, nsIURI* aReferringURI,
                       PRInt32 aTransitionType, PRBool aIsRedirect,
                       PRInt64 aSessionID, PRInt64* aVisitID)
{
  NS_ENSURE_ARG_POINTER(aURI);

  // Filter out unwanted URIs, silently failing
  PRBool canAdd = PR_FALSE;
  nsresult rv = CanAddURI(aURI, &canAdd);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!canAdd) {
    *aVisitID = 0;
    return NS_OK;
  }

  // This will prevent corruption since we have to do a two-phase add.
  // Generally this won't do anything because AddURI has its own transaction.
  mozStorageTransaction transaction(mDBConn, PR_FALSE);

  // see if this is an update (revisit) or a new page
  mozStorageStatementScoper scoper(mDBGetPageVisitStats);
  rv = BindStatementURI(mDBGetPageVisitStats, 0, aURI);
  NS_ENSURE_SUCCESS(rv, rv);
  PRBool alreadyVisited = PR_FALSE;
  rv = mDBGetPageVisitStats->ExecuteStep(&alreadyVisited);
  NS_ENSURE_SUCCESS(rv, rv);

  PRInt64 pageID = 0;
  PRBool hidden; // XXX fix me, this should not be a PRBool, as we later do BindInt32Parameter()
  PRBool typed;  // XXX fix me, this should not be a PRBool, as we later do BindInt32Parameter()
  PRBool newItem = PR_FALSE; // used to send out notifications at the end
  if (alreadyVisited) {
    // Update the existing entry...
    rv = mDBGetPageVisitStats->GetInt64(0, &pageID);
    NS_ENSURE_SUCCESS(rv, rv);

    PRInt32 oldVisitCount = 0;
    rv = mDBGetPageVisitStats->GetInt32(1, &oldVisitCount);
    NS_ENSURE_SUCCESS(rv, rv);

    PRInt32 oldTypedState = 0;
    rv = mDBGetPageVisitStats->GetInt32(2, &oldTypedState);
    NS_ENSURE_SUCCESS(rv, rv);

    PRBool oldHiddenState = 0;
    rv = mDBGetPageVisitStats->GetInt32(3, &oldHiddenState);
    NS_ENSURE_SUCCESS(rv, rv);

    // free the previous statement before we make a new one
    mDBGetPageVisitStats->Reset();
    scoper.Abandon();

    // embedded links and redirects will be hidden, but don't hide pages that
    // are already unhidden.
    //
    // Note that we test the redirect flag and not for the redirect transition
    // type. The transition type refers to how we got here, and whether a page
    // is shown does not depend on whether you got to it through a redirect.
    // Rather, we want to hide pages that do not themselves redirect somewhere
    // else, which is what the redirect flag means.
    //
    // note, we want to unhide any hidden pages that the user explicitly types
    // (aTransitionType == TRANSITION_TYPED) so that they will appear in
    // the history UI (sidebar, history menu, url bar autocomplete, etc)
    hidden = oldHiddenState;
    if (hidden && (!aIsRedirect || aTransitionType == TRANSITION_TYPED) &&
        aTransitionType != TRANSITION_EMBED)
      hidden = PR_FALSE; // unhide

    typed = oldTypedState || (aTransitionType == TRANSITION_TYPED);

    // some items may have a visit count of 0 which will not count for link
    // visiting, so be sure to note this transition
    if (oldVisitCount == 0)
      newItem = PR_TRUE;

    // update with new stats
    mozStorageStatementScoper updateScoper(mDBUpdatePageVisitStats);
    rv = mDBUpdatePageVisitStats->BindInt64Parameter(0, pageID);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBUpdatePageVisitStats->BindInt32Parameter(1, hidden);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mDBUpdatePageVisitStats->BindInt32Parameter(2, typed);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBUpdatePageVisitStats->Execute();
    NS_ENSURE_SUCCESS(rv, rv);
  } else {
    // New page
    newItem = PR_TRUE;

    // free the previous statement before we make a new one
    mDBGetPageVisitStats->Reset();
    scoper.Abandon();

    // Hide only embedded links and redirects
    // See the hidden computation code above for a little more explanation.
    hidden = (aTransitionType == TRANSITION_EMBED || aIsRedirect);

    typed = (aTransitionType == TRANSITION_TYPED);

    // set as visited once, no title
    nsString voidString;
    voidString.SetIsVoid(PR_TRUE);
    rv = InternalAddNewPage(aURI, voidString, hidden, typed, 1, PR_TRUE, &pageID);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Get the place id for the referrer, if we have one
  PRInt64 referringVisitID = 0;
  PRInt64 referringSessionID;
  if (aReferringURI &&
      !FindLastVisit(aReferringURI, &referringVisitID, &referringSessionID)) {
    // Add the referrer
    rv = AddVisit(aReferringURI, aTime - 1, nsnull, TRANSITION_LINK, PR_FALSE,
                  aSessionID, &referringVisitID);
    if (NS_FAILED(rv))
      referringVisitID = 0;
  }

  rv = InternalAddVisit(pageID, referringVisitID, aSessionID, aTime,
                        aTransitionType, aVisitID);
  transaction.Commit();

  // Update frecency (*after* the visit info is in the db)
  // Swallow errors here, since if we've gotten this far, it's more
  // important to notify the observers below.
  (void)UpdateFrecency(pageID, PR_FALSE);

  // Notify observers: The hidden detection code must match that in
  // GetQueryResults to maintain consistency.
  // FIXME bug 325241: make a way to observe hidden URLs
  PRUint32 added = 0;
  if (!hidden && aTransitionType != TRANSITION_EMBED &&
                 aTransitionType != TRANSITION_DOWNLOAD) {
    ENUMERATE_WEAKARRAY(mObservers, nsINavHistoryObserver,
                        OnVisit(aURI, *aVisitID, aTime, aSessionID,
                                referringVisitID, aTransitionType, &added));
  }

  // Normally docshell sends the link visited observer notification for us (this
  // will tell all the documents to update their visited link coloring).
  // However, for redirects (since we implement nsIGlobalHistory3) and downloads
  // (since we implement nsIDownloadHistory) this will not happen and we need to
  // send it ourselves.
  if (newItem && (aIsRedirect || aTransitionType == TRANSITION_DOWNLOAD)) {
    nsCOMPtr<nsIObserverService> obsService =
      do_GetService("@mozilla.org/observer-service;1");
    if (obsService)
      obsService->NotifyObservers(aURI, NS_LINK_VISITED_EVENT_TOPIC, nsnull);
  }

  return NS_OK;
}


// nsNavHistory::GetNewQuery

NS_IMETHODIMP nsNavHistory::GetNewQuery(nsINavHistoryQuery **_retval)
{
  *_retval = new nsNavHistoryQuery();
  if (! *_retval)
    return NS_ERROR_OUT_OF_MEMORY;
  NS_ADDREF(*_retval);
  return NS_OK;
}

// nsNavHistory::GetNewQueryOptions

NS_IMETHODIMP nsNavHistory::GetNewQueryOptions(nsINavHistoryQueryOptions **_retval)
{
  *_retval = new nsNavHistoryQueryOptions();
  NS_ENSURE_TRUE(*_retval, NS_ERROR_OUT_OF_MEMORY);
  NS_ADDREF(*_retval);
  return NS_OK;
}

// nsNavHistory::ExecuteQuery
//

NS_IMETHODIMP
nsNavHistory::ExecuteQuery(nsINavHistoryQuery *aQuery, nsINavHistoryQueryOptions *aOptions,
                           nsINavHistoryResult** _retval)
{
  return ExecuteQueries(&aQuery, 1, aOptions, _retval);
}


// nsNavHistory::ExecuteQueries
//
//    This function is actually very simple, we just create the proper root node (either
//    a bookmark folder or a complex query node) and assign it to the result. The node
//    will then populate itself accordingly.
//
//    Quick overview of query operation: When you call this function, we will construct
//    the correct container node and set the options you give it. This node will then
//    fill itself. Folder nodes will call nsNavBookmarks::QueryFolderChildren, and
//    all other queries will call GetQueryResults. If these results contain other
//    queries, those will be populated when the container is opened.

NS_IMETHODIMP
nsNavHistory::ExecuteQueries(nsINavHistoryQuery** aQueries, PRUint32 aQueryCount,
                             nsINavHistoryQueryOptions *aOptions,
                             nsINavHistoryResult** _retval)
{
  nsresult rv;
  NS_ENSURE_ARG_POINTER(aQueries);
  NS_ENSURE_ARG_POINTER(aOptions);
  if (! aQueryCount)
    return NS_ERROR_INVALID_ARG;

  // concrete options
  nsCOMPtr<nsNavHistoryQueryOptions> options = do_QueryInterface(aOptions);
  NS_ENSURE_TRUE(options, NS_ERROR_INVALID_ARG);

  // concrete queries array
  nsCOMArray<nsNavHistoryQuery> queries;
  for (PRUint32 i = 0; i < aQueryCount; i ++) {
    nsCOMPtr<nsNavHistoryQuery> query = do_QueryInterface(aQueries[i], &rv);
    NS_ENSURE_SUCCESS(rv, rv);
    queries.AppendObject(query);
  }

  // root node
  nsRefPtr<nsNavHistoryContainerResultNode> rootNode;
  PRInt64 folderId = GetSimpleBookmarksQueryFolder(queries, options);
  if (folderId) {
    // In the simple case where we're just querying children of a single bookmark
    // folder, we can more efficiently generate results.
    nsNavBookmarks* bookmarks = nsNavBookmarks::GetBookmarksService();
    NS_ENSURE_TRUE(bookmarks, NS_ERROR_OUT_OF_MEMORY);
    nsRefPtr<nsNavHistoryResultNode> tempRootNode;
    rv = bookmarks->ResultNodeForContainer(folderId, options,
                                           getter_AddRefs(tempRootNode));
    NS_ENSURE_SUCCESS(rv, rv);
    rootNode = tempRootNode->GetAsContainer();
  } else {
    // complex query
    rootNode = new nsNavHistoryQueryResultNode(EmptyCString(), EmptyCString(),
                                               queries, options);
    NS_ENSURE_TRUE(rootNode, NS_ERROR_OUT_OF_MEMORY);
  }

  // result object
  nsRefPtr<nsNavHistoryResult> result;
  rv = nsNavHistoryResult::NewHistoryResult(aQueries, aQueryCount, options, rootNode,
                                            getter_AddRefs(result));
  NS_ENSURE_SUCCESS(rv, rv);

  NS_ADDREF(*_retval = result);
  return NS_OK;
}

// determine from our nsNavHistoryQuery array and nsNavHistoryQueryOptions
// if this is the place query from the history menu.
// from browser-menubar.inc, our history menu query is:
// place:type=0&sort=4&maxResults=10
// note, any maxResult > 0 will still be considered a history menu query
// or if this is the place query from the "Most Visited" item in the "Smart Bookmarks" folder:
// place:queryType=0&sort=8&maxResults=10
// note, any maxResult > 0 will still be considered a Most Visited menu query
static
PRBool IsHistoryMenuQuery(const nsCOMArray<nsNavHistoryQuery>& aQueries, nsNavHistoryQueryOptions *aOptions, PRUint16 aSortMode)
{
  if (aQueries.Count() != 1)
    return PR_FALSE;

  nsNavHistoryQuery *aQuery = aQueries[0];
 
  if (aOptions->QueryType() != nsINavHistoryQueryOptions::QUERY_TYPE_HISTORY)
    return PR_FALSE;

  if (aOptions->ResultType() != nsINavHistoryQueryOptions::RESULTS_AS_URI)
    return PR_FALSE;

  if (aOptions->SortingMode() != aSortMode)
    return PR_FALSE;

  if (aOptions->MaxResults() <= 0)
    return PR_FALSE;

  if (aOptions->ExcludeItems())
    return PR_FALSE;

  if (aOptions->IncludeHidden())
    return PR_FALSE;

  if (aQuery->MinVisits() != -1 || aQuery->MaxVisits() != -1)
    return PR_FALSE;

  if (aQuery->BeginTime() || aQuery->BeginTimeReference()) 
    return PR_FALSE;

  if (aQuery->EndTime() || aQuery->EndTimeReference()) 
    return PR_FALSE;

  if (!aQuery->SearchTerms().IsEmpty()) 
    return PR_FALSE;

  if (aQuery->OnlyBookmarked()) 
    return PR_FALSE;

  if (aQuery->DomainIsHost() || !aQuery->Domain().IsEmpty())
    return PR_FALSE;

  if (aQuery->AnnotationIsNot() || !aQuery->Annotation().IsEmpty()) 
    return PR_FALSE;

  if (aQuery->UriIsPrefix() || aQuery->Uri()) 
    return PR_FALSE;

  if (aQuery->Folders().Length() > 0)
    return PR_FALSE;

  return PR_TRUE;
}

static
PRBool NeedToFilterResultSet(const nsCOMArray<nsNavHistoryQuery>& aQueries, 
                             nsNavHistoryQueryOptions *aOptions)
{
  // Always filter bookmarks queries to avoid  the inclusion of query nodes
  if (aOptions->QueryType() == nsINavHistoryQueryOptions::QUERY_TYPE_BOOKMARKS)
    return PR_TRUE;

  nsCString parentAnnotationToExclude;
  nsresult rv = aOptions->GetExcludeItemIfParentHasAnnotation(parentAnnotationToExclude);
  NS_ENSURE_SUCCESS(rv, PR_TRUE);
  if (!parentAnnotationToExclude.IsEmpty())
    return PR_TRUE;

  PRInt32 i;
  for (i = 0; i < aQueries.Count(); i ++) {
    if (aQueries[i]->Folders().Length() != 0) {
      return PR_TRUE;
    } else {
      PRBool hasSearchTerms;
      nsresult rv = aQueries[i]->GetHasSearchTerms(&hasSearchTerms);
      if (NS_FAILED(rv) || hasSearchTerms)
        return PR_TRUE;
    }
  }
  return PR_FALSE;
}

// ** Helper class for ConstructQueryString **/

static const PRInt32 MAX_HISTORY_DAYS = 6;

class PlacesSQLQueryBuilder
{
public:
  PlacesSQLQueryBuilder(const nsCString& aConditions,
                        nsNavHistoryQueryOptions* aOptions,
                        PRBool aUseLimit,
                        nsNavHistory::StringHash& aAddParams);

  nsresult GetQueryString(nsCString& aQueryString);

private:
  nsresult Select();

  nsresult SelectAsURI();
  nsresult SelectAsVisit();
  nsresult SelectAsDay();
  nsresult SelectAsSite();
  nsresult SelectAsTag();

  nsresult Where();
  nsresult GroupBy();
  nsresult OrderBy();
  nsresult Limit();

  void OrderByColumnIndexAsc(PRInt32 aIndex);
  void OrderByColumnIndexDesc(PRInt32 aIndex);

  const nsCString& mConditions;
  PRBool mUseLimit;

  PRUint16 mResultType;
  PRUint16 mQueryType;
  PRBool mIncludeHidden;
  PRUint16 mSortingMode;
  PRUint32 mMaxResults;

  nsCString mQueryString;
  nsCString mGroupBy;
  PRBool mHasDateColumns;
  PRBool mSkipOrderBy;
  nsNavHistory::StringHash& mAddParams;
};

PlacesSQLQueryBuilder::PlacesSQLQueryBuilder(
    const nsCString& aConditions, 
    nsNavHistoryQueryOptions* aOptions, 
    PRBool aUseLimit,
    nsNavHistory::StringHash& aAddParams) :
  mConditions(aConditions),
  mUseLimit(aUseLimit),
  mResultType(aOptions->ResultType()),
  mQueryType(aOptions->QueryType()),
  mIncludeHidden(aOptions->IncludeHidden()),
  mSortingMode(aOptions->SortingMode()),
  mMaxResults(aOptions->MaxResults()),
  mSkipOrderBy(PR_FALSE),
  mAddParams(aAddParams)
{
  mHasDateColumns = (mQueryType == nsINavHistoryQueryOptions::QUERY_TYPE_BOOKMARKS);
}

nsresult
PlacesSQLQueryBuilder::GetQueryString(nsCString& aQueryString)
{
  nsresult rv = Select();
  NS_ENSURE_SUCCESS(rv, rv);
  rv = Where();
  NS_ENSURE_SUCCESS(rv, rv);
  rv = GroupBy();
  NS_ENSURE_SUCCESS(rv, rv);
  rv = OrderBy();
  NS_ENSURE_SUCCESS(rv, rv);
  rv = Limit();
  NS_ENSURE_SUCCESS(rv, rv);

  aQueryString = mQueryString;
  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::Select()
{
  nsresult rv;

  switch (mResultType)
  {
    case nsINavHistoryQueryOptions::RESULTS_AS_URI:
    case nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS:
      rv = SelectAsURI();
      NS_ENSURE_SUCCESS(rv, rv);
      break;

    case nsINavHistoryQueryOptions::RESULTS_AS_VISIT:
    case nsINavHistoryQueryOptions::RESULTS_AS_FULL_VISIT:
      rv = SelectAsVisit();
      NS_ENSURE_SUCCESS(rv, rv);
      break;

    case nsINavHistoryQueryOptions::RESULTS_AS_DATE_QUERY:
    case nsINavHistoryQueryOptions::RESULTS_AS_DATE_SITE_QUERY:
      rv = SelectAsDay();
      NS_ENSURE_SUCCESS(rv, rv);
      break;

    case nsINavHistoryQueryOptions::RESULTS_AS_SITE_QUERY:
      rv = SelectAsSite();
      NS_ENSURE_SUCCESS(rv, rv);
      break;

    case nsINavHistoryQueryOptions::RESULTS_AS_TAG_QUERY:
      rv = SelectAsTag();
      NS_ENSURE_SUCCESS(rv, rv);
      break;

    default:
      NS_NOTREACHED("Invalid result type");
  }
  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::SelectAsURI()
{
  switch (mQueryType)
  {
    case nsINavHistoryQueryOptions::QUERY_TYPE_HISTORY:
      mQueryString = NS_LITERAL_CSTRING(
        "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count, "
          "MAX(visit_date), f.url, null, null "
        "FROM moz_places h "
             "LEFT OUTER JOIN moz_historyvisits v ON h.id = v.place_id "
             "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id ");

      if (!mIncludeHidden)
        mQueryString += NS_LITERAL_CSTRING(
          " WHERE h.hidden <> 1 AND v.visit_type NOT IN (0,4)"
            " {ADDITIONAL_CONDITIONS} ");

      mGroupBy = NS_LITERAL_CSTRING(" GROUP BY h.id");
      break;

    case nsINavHistoryQueryOptions::QUERY_TYPE_BOOKMARKS:
      // Don't initialize on var creation, that would give an error on compile
      // because we are in the same scope of the switch clause and the var could
      // not be initialized. Do an assignment rather than an initialization.
      nsNavHistory* history;
      history = nsNavHistory::GetHistoryService();
      NS_ENSURE_STATE(history);

      if (mResultType == nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS) {
        // Order-by clause is hardcoded because we need to discard duplicates
        // in FilterResultSet. We will retain only the last modified item,
        // so we are ordering by place id and last modified to do a faster
        // filtering.
        mSkipOrderBy = PR_TRUE;

        mQueryString = NS_LITERAL_CSTRING(
          "SELECT b2.fk, h.url, COALESCE(b2.title, h.title), h.rev_host, "
            "h.visit_count, "
            SQL_STR_FRAGMENT_MAX_VISIT_DATE( "b2.fk" )
            ", f.url, null, b2.id, b2.dateAdded, b2.lastModified "
          "FROM moz_bookmarks b2 "
            "JOIN moz_places h ON b2.fk = h.id AND b2.type = 1 "
            "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
            "WHERE b2.id IN ("
              "SELECT b1.id FROM moz_bookmarks b1 "
              "WHERE b1.fk IN "
                "(SELECT b.fk FROM moz_bookmarks b WHERE b.type = 1 {ADDITIONAL_CONDITIONS}) "
              "AND NOT EXISTS "
                "(SELECT id FROM moz_bookmarks WHERE id = b1.parent AND parent = ") +
                nsPrintfCString("%lld", history->GetTagsFolder()) +
              NS_LITERAL_CSTRING(")) ORDER BY b2.fk DESC, b2.lastModified DESC");
      }
      else {
        mQueryString = NS_LITERAL_CSTRING(
          "SELECT b.fk, h.url, COALESCE(b.title, h.title), h.rev_host, "
            "h.visit_count,"
            SQL_STR_FRAGMENT_MAX_VISIT_DATE( "b.fk" )
            ", f.url, null, b.id, b.dateAdded, b.lastModified "
          "FROM moz_bookmarks b "
          "JOIN moz_places h ON b.fk = h.id AND b.type = 1 "
          "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
          "WHERE NOT EXISTS "
            "(SELECT id FROM moz_bookmarks WHERE id = b.parent AND parent = ") +
            nsPrintfCString("%lld", history->GetTagsFolder()) +
            NS_LITERAL_CSTRING(") {ADDITIONAL_CONDITIONS}");
      }
      break;

    default:
      return NS_ERROR_NOT_IMPLEMENTED;
  }
  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::SelectAsVisit()
{
  mQueryString = NS_LITERAL_CSTRING(
    "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count, "
      "v.visit_date, f.url, v.session, null "
    "FROM moz_places h "
         "LEFT OUTER JOIN moz_historyvisits v ON h.id = v.place_id "
         "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id ");

  if (!mIncludeHidden)
    mQueryString += NS_LITERAL_CSTRING(
      " WHERE h.hidden <> 1 AND v.visit_type NOT IN (0,4)"
        " {ADDITIONAL_CONDITIONS} ");

  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::SelectAsDay()
{
  mSkipOrderBy = PR_TRUE;
  PRBool asDayQuery = 
    mResultType == nsINavHistoryQueryOptions::RESULTS_AS_DATE_QUERY;

  mQueryString = nsPrintfCString(255,
    "SELECT null, "
      "'place:type=%ld&sort=%ld&beginTime='||beginTime||'&endTime='||endTime, "
      "dayTitle, null, null, endTime, null, null, null, null "
    "FROM (", // TOUTER BEGIN
    (asDayQuery
       ?nsINavHistoryQueryOptions::RESULTS_AS_URI
       :nsINavHistoryQueryOptions::RESULTS_AS_SITE_QUERY),
     nsINavHistoryQueryOptions::SORT_BY_TITLE_ASCENDING);

  nsNavHistory* history = nsNavHistory::GetHistoryService();
  NS_ENSURE_STATE(history);

  struct Midnight
  {
    Midnight() {
      mNow = NormalizeTimeRelativeToday(PR_Now());  
    }
    PRTime Get(PRInt32 aDayOffset) {
      PRTime result;
      LL_MUL(result, aDayOffset, USECS_PER_DAY);
      LL_ADD(result, result, mNow);
      return result;
    }
    PRTime mNow;
  } midnight;

  nsCAutoString dateParam;
  nsCAutoString dateName;

  for (PRInt32 i = 0; i <= MAX_HISTORY_DAYS; i++) {
    dateParam = nsPrintfCString(":dayTitle%d", i);
    switch (i)
    {
      case 0:
        history->GetStringFromName(
            NS_LITERAL_STRING("finduri-AgeInDays-is-0").get(), dateName);
        break;
      case 1:
        history->GetStringFromName(
            NS_LITERAL_STRING("finduri-AgeInDays-is-1").get(), dateName);
        break;
      default:
        history->GetAgeInDaysString(i, 
            NS_LITERAL_STRING("finduri-AgeInDays-is").get(), dateName);
        break;
    }

    mAddParams.Put(dateParam, dateName);

    PRInt32 fromDayAgo = -i;
    PRInt32 toDayAgo = -i + 1;

    nsPrintfCString dayRange(1024,
      "SELECT * "
      "FROM (SELECT %d dayOrder, "
                  "'%d' dayRange, "
                  "%s dayTitle, " // This will be bound
                  "%llu beginTime, "
                  "%llu endTime "
      "FROM  moz_historyvisits "
      "WHERE visit_date >= %llu AND visit_date < %llu "
      "  AND visit_type NOT IN (0,4) "
      "LIMIT 1) TUNION%d UNION ", 
      i, i, dateParam.get(), 
      midnight.Get(fromDayAgo),
      midnight.Get(toDayAgo), 
      midnight.Get(fromDayAgo),
      midnight.Get(toDayAgo),
      i);

    mQueryString.Append( dayRange );
  }

  dateParam = nsPrintfCString(":dayTitle%d", MAX_HISTORY_DAYS+1);
  history->GetAgeInDaysString(MAX_HISTORY_DAYS, 
    NS_LITERAL_STRING("finduri-AgeInDays-isgreater").get(), dateName);

  mAddParams.Put(dateParam, dateName);

  mQueryString.Append(nsPrintfCString(1024,
    "SELECT * "
    "FROM (SELECT %d dayOrder, "
                 "'%d+' dayRange, "
                 "%s dayTitle, " // This will be bound
                 "1 beginTime, "
                 "%llu endTime "
          "FROM  moz_historyvisits "
          "WHERE visit_date < %llu "
          "  AND visit_type NOT IN (0,4) "
          "LIMIT 1) TUNIONLAST "
    ") TOUTER " // TOUTER END
    "ORDER BY dayOrder ASC",
    MAX_HISTORY_DAYS+1,
    MAX_HISTORY_DAYS+1,
    dateParam.get(),
    midnight.Get(-MAX_HISTORY_DAYS),
    midnight.Get(-MAX_HISTORY_DAYS)
    ));

  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::SelectAsSite()
{
  nsCAutoString localFiles;

  nsNavHistory* history = nsNavHistory::GetHistoryService();
  NS_ENSURE_STATE(history);

  history->GetStringFromName(NS_LITERAL_STRING("localhost").get(), localFiles);
  mAddParams.Put(NS_LITERAL_CSTRING(":localhost"), localFiles);

  // We want just sites, but from whole database.
  if (mConditions.IsEmpty()) {

    mQueryString = nsPrintfCString(2048,
      "SELECT DISTINCT null, "
             "'place:type=%ld&sort=%ld&domain=&domainIsHost=true', "
             ":localhost, :localhost, null, null, null, null, null "
      "WHERE EXISTS(SELECT '*' "
                   "FROM moz_places "
                   "WHERE hidden <> 1 AND rev_host = '.' "
                     "AND visit_count > 0 "
                     "AND url BETWEEN 'file://' AND 'file:/~') "
      "UNION ALL "
      "SELECT DISTINCT null, "
             "'place:type=%ld&sort=%ld&domain='||host||'&domainIsHost=true', "
             "host, host, null, null, null, null, null "
      "FROM (SELECT get_unreversed_host(rev_host) host "
            "FROM (SELECT DISTINCT rev_host "
                  "FROM moz_places "
                  "WHERE hidden <> 1 AND rev_host <> '.' "
                    "AND visit_count > 0 ) inner0 "
            "ORDER BY 1 ASC) inner1",
      nsINavHistoryQueryOptions::RESULTS_AS_URI,
      nsINavHistoryQueryOptions::SORT_BY_TITLE_ASCENDING,
      nsINavHistoryQueryOptions::RESULTS_AS_URI,
      nsINavHistoryQueryOptions::SORT_BY_TITLE_ASCENDING);
  // Now we need to use the filters - we need them all
  } else {

    mQueryString = nsPrintfCString(4096,
      "SELECT DISTINCT null, "
             "'place:type=%ld&sort=%ld&domain=&domainIsHost=true"
               "&beginTime='||:begin_time||'&endTime='||:end_time, "
             ":localhost, :localhost, null, null, null, null, null "
      "WHERE EXISTS(SELECT '*' "
                   "FROM moz_places h  "
                        "JOIN moz_historyvisits v ON h.id = v.place_id "
                   "WHERE h.hidden <> 1 AND h.rev_host = '.' "
                     "AND h.visit_count > 0 "
                     "AND h.url BETWEEN 'file://' AND 'file:/~' "
                     "AND v.visit_type NOT IN (0,4) {ADDITIONAL_CONDITIONS} ) "
      "UNION ALL "
      "SELECT DISTINCT null, "
             "'place:type=%ld&sort=%ld&domain='||host||'&domainIsHost=true"
               "&beginTime='||:begin_time||'&endTime='||:end_time, "
             "host, host, null, null, null, null, null "
      "FROM (SELECT get_unreversed_host(rev_host) host "
            "FROM (SELECT DISTINCT rev_host "
                  "FROM moz_places h "
                       "JOIN moz_historyvisits v ON h.id = v.place_id "
                  "WHERE h.hidden <> 1 AND h.rev_host <> '.' "
                    "AND h.visit_count > 0 "
                    "AND v.visit_type NOT IN (0,4) "
                    "{ADDITIONAL_CONDITIONS} ) inner0 "
            "ORDER BY 1 ASC) inner1",
      nsINavHistoryQueryOptions::RESULTS_AS_URI,
      nsINavHistoryQueryOptions::SORT_BY_TITLE_ASCENDING,
      nsINavHistoryQueryOptions::RESULTS_AS_URI,
      nsINavHistoryQueryOptions::SORT_BY_TITLE_ASCENDING);
  }

  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::SelectAsTag()
{
  nsNavHistory* history = nsNavHistory::GetHistoryService();
  NS_ENSURE_STATE(history);

  // This allows sorting by date fields what is not possible with
  // other history queries.
  mHasDateColumns = PR_TRUE; 

  mQueryString = nsPrintfCString(2048,
    "SELECT null, 'place:folder=' || id || '&queryType=%d&type=%ld', "
      "title, null, null, null, null, null, null, dateAdded, lastModified "
    "FROM   moz_bookmarks "
    "WHERE  parent = %lld",
    nsINavHistoryQueryOptions::QUERY_TYPE_BOOKMARKS,
    nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS,
    history->GetTagsFolder());

  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::Where()
{
  // If we used WHERE already, we inject the conditions 
  // in place of {ADDITIONAL_CONDITIONS}
  PRInt32 useInnerCondition;
  useInnerCondition = mQueryString.Find("{ADDITIONAL_CONDITIONS}", 0);
  if (useInnerCondition != kNotFound) {

    nsCAutoString innerCondition;
    // If we have condition AND it
    if (!mConditions.IsEmpty()) {
      innerCondition = " AND (";
      innerCondition += mConditions;
      innerCondition += ")";
    }
    mQueryString.ReplaceSubstring("{ADDITIONAL_CONDITIONS}",
                                  innerCondition.get());

  } else if (!mConditions.IsEmpty()) {

    mQueryString += "WHERE ";
    mQueryString += mConditions;

  }
  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::GroupBy()
{
  mQueryString += mGroupBy;
  return NS_OK;
}

nsresult
PlacesSQLQueryBuilder::OrderBy()
{
  if (mSkipOrderBy)
    return NS_OK;

  // Sort clause: we will sort later, but if it comes out of the DB sorted,
  // our later sort will be basically free. The DB can sort these for free
  // most of the time anyway, because it has indices over these items.
  switch(mSortingMode)
  {
    case nsINavHistoryQueryOptions::SORT_BY_NONE:
      break;
    case nsINavHistoryQueryOptions::SORT_BY_TITLE_ASCENDING:
    case nsINavHistoryQueryOptions::SORT_BY_TITLE_DESCENDING:
      // the DB doesn't have indices on titles, and we need to do special
      // sorting for locales. This type of sorting is done only at the end.
      //
      // If the user wants few results, we limit them by date, necessitating
      // a sort by date here (see the IDL definition for maxResults). We'll
      // still do the official sort by title later.
      if (mMaxResults > 0)
        OrderByColumnIndexDesc(nsNavHistory::kGetInfoIndex_VisitDate);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_DATE_ASCENDING:
      OrderByColumnIndexAsc(nsNavHistory::kGetInfoIndex_VisitDate);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_DATE_DESCENDING:
      OrderByColumnIndexDesc(nsNavHistory::kGetInfoIndex_VisitDate);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_URI_ASCENDING:
      OrderByColumnIndexAsc(nsNavHistory::kGetInfoIndex_URL);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_URI_DESCENDING:
      OrderByColumnIndexDesc(nsNavHistory::kGetInfoIndex_URL);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_VISITCOUNT_ASCENDING:
      OrderByColumnIndexAsc(nsNavHistory::kGetInfoIndex_VisitCount);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_VISITCOUNT_DESCENDING:
      OrderByColumnIndexDesc(nsNavHistory::kGetInfoIndex_VisitCount);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_DATEADDED_ASCENDING:
      if (mHasDateColumns)
        OrderByColumnIndexAsc(nsNavHistory::kGetInfoIndex_ItemDateAdded);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_DATEADDED_DESCENDING:
      if (mHasDateColumns)
        OrderByColumnIndexDesc(nsNavHistory::kGetInfoIndex_ItemDateAdded);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_LASTMODIFIED_ASCENDING:
      if (mHasDateColumns)
        OrderByColumnIndexAsc(nsNavHistory::kGetInfoIndex_ItemLastModified);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_LASTMODIFIED_DESCENDING:
      if (mHasDateColumns)
        OrderByColumnIndexDesc(nsNavHistory::kGetInfoIndex_ItemLastModified);
      break;
    case nsINavHistoryQueryOptions::SORT_BY_TAGS_ASCENDING:
    case nsINavHistoryQueryOptions::SORT_BY_TAGS_DESCENDING:
    case nsINavHistoryQueryOptions::SORT_BY_ANNOTATION_ASCENDING:
    case nsINavHistoryQueryOptions::SORT_BY_ANNOTATION_DESCENDING:
      break; // Sort later in nsNavHistoryQueryResultNode::FillChildren()
    default:
      NS_NOTREACHED("Invalid sorting mode");
  }
  return NS_OK;
}

void PlacesSQLQueryBuilder::OrderByColumnIndexAsc(PRInt32 aIndex)
{
  mQueryString += nsPrintfCString(128, " ORDER BY %d ASC", aIndex+1);
}

void PlacesSQLQueryBuilder::OrderByColumnIndexDesc(PRInt32 aIndex)
{
  mQueryString += nsPrintfCString(128, " ORDER BY %d DESC", aIndex+1);
}

nsresult
PlacesSQLQueryBuilder::Limit()
{
  if (mUseLimit && mMaxResults > 0) {
    mQueryString += NS_LITERAL_CSTRING(" LIMIT ");
    mQueryString.AppendInt(mMaxResults);
    mQueryString.AppendLiteral(" ");
  }
  return NS_OK;
}

nsresult
nsNavHistory::ConstructQueryString(
    const nsCOMArray<nsNavHistoryQuery>& aQueries,
    nsNavHistoryQueryOptions* aOptions, 
    nsCString& queryString, 
    PRBool& aParamsPresent,
    nsNavHistory::StringHash& aAddParams)
{
  nsresult rv;

  // Information about visit_type:
  // 4 == TRANSITION_EMBED
  // 0 == undefined (see bug #375777 for details)
  // Some sites, especially Javascript-heavy ones, load things in frames to 
  // display them, resulting in a lot of these entries. This is the reason 
  // why such visits are filtered out.

  aParamsPresent = PR_FALSE;

  PRInt32 sortingMode = aOptions->SortingMode();
  if (sortingMode < 0 ||
      sortingMode > nsINavHistoryQueryOptions::SORT_BY_ANNOTATION_DESCENDING) {
    return NS_ERROR_INVALID_ARG;
  }

  // for the very special query for the history menu 
  // we generate a super-optimized SQL query
  if (IsHistoryMenuQuery(aQueries, aOptions, 
        nsINavHistoryQueryOptions::SORT_BY_DATE_DESCENDING)) {

    queryString = NS_LITERAL_CSTRING(
      "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count, "
        SQL_STR_FRAGMENT_MAX_VISIT_DATE( "h.id" )
        ", f.url, null, null "
      "FROM moz_places h "
      "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
      "WHERE h.id IN ( "
        "SELECT DISTINCT p.id "
        "FROM moz_places p "
        "JOIN moz_historyvisits v ON v.place_id = p.id "
        "WHERE p.hidden <> 1 AND v.visit_type NOT IN (0,4) "
        "ORDER BY v.visit_date DESC "
        "LIMIT ");
    queryString.AppendInt(aOptions->MaxResults());
    queryString += NS_LITERAL_CSTRING(") ORDER BY 6 DESC"); // v.visit_date
    return NS_OK;
  }

  // for the most visited menu query
  // we generate a super-optimized SQL query
  if (IsHistoryMenuQuery(aQueries, aOptions, 
        nsINavHistoryQueryOptions::SORT_BY_VISITCOUNT_DESCENDING)) {
    queryString = NS_LITERAL_CSTRING(
      "SELECT h.id, h.url, h.title, h.rev_host, h.visit_count, "
        SQL_STR_FRAGMENT_MAX_VISIT_DATE( "h.id" )
        ", f.url, null, null "
      "FROM moz_places h "
      "LEFT OUTER JOIN moz_favicons f ON h.favicon_id = f.id "
      "WHERE h.id IN ("
        "SELECT p.id FROM moz_places p "
        "WHERE p.hidden <> 1 AND visit_count > 0 "
        "ORDER BY p.visit_count DESC LIMIT ");
    queryString.AppendInt(aOptions->MaxResults());
    queryString += NS_LITERAL_CSTRING(") ORDER BY h.visit_count DESC");
    return NS_OK;
  }  

  nsCAutoString conditions;

  PRInt32 i;
  for (i = 0; i < aQueries.Count(); i ++) {
    nsCString queryClause;
    rv = QueryToSelectClause(aQueries[i], aOptions, i, &queryClause);
    NS_ENSURE_SUCCESS(rv, rv);
    if (! queryClause.IsEmpty()) {
      aParamsPresent = PR_TRUE;
      if (! conditions.IsEmpty()) // exists previous clause: multiple ones are ORed
        conditions += NS_LITERAL_CSTRING(" OR ");
      conditions += NS_LITERAL_CSTRING("(") + queryClause +
        NS_LITERAL_CSTRING(")");
    }
  }

  // Determine whether we can push maxResults constraints into the queries 
  // as LIMIT, or if we need to do result count clamping later 
  // using FilterResultSet()
  PRBool useLimitClause = !NeedToFilterResultSet(aQueries, aOptions);

  PlacesSQLQueryBuilder queryStringBuilder(conditions, aOptions, 
                                           useLimitClause, aAddParams);
  rv = queryStringBuilder.GetQueryString(queryString);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

PLDHashOperator BindAdditionalParameter(nsNavHistory::StringHash::KeyType aParamName, 
                                        nsCString aParamValue,
                                        void* aStatement)
{
  mozIStorageStatement* stmt = static_cast<mozIStorageStatement*>(aStatement);

  PRUint32 index;
  nsresult rv = stmt->GetParameterIndex(aParamName, &index);

  if (NS_FAILED(rv))
    return PL_DHASH_STOP;

  rv = stmt->BindUTF8StringParameter(index, aParamValue);
  if (NS_FAILED(rv))
    return PL_DHASH_STOP;

  return PL_DHASH_NEXT;
}

// nsNavHistory::GetQueryResults
//
//    Call this to get the results from a complex query. This is used by
//    nsNavHistoryQueryResultNode to populate its children. For simple bookmark
//    queries, use nsNavBookmarks::QueryFolderChildren.
//
//    THIS DOES NOT DO SORTING. You will need to sort the container yourself
//    when you get the results. This is because sorting depends on tree
//    statistics that will be built from the perspective of the tree. See
//    nsNavHistoryQueryResultNode::FillChildren
//
//    FIXME: This only does keyword searching for the first query, and does
//    it ANDed with the all the rest of the queries.

nsresult
nsNavHistory::GetQueryResults(nsNavHistoryQueryResultNode *aResultNode,
                              const nsCOMArray<nsNavHistoryQuery>& aQueries,
                              nsNavHistoryQueryOptions *aOptions,
                              nsCOMArray<nsNavHistoryResultNode>* aResults)
{
  NS_ENSURE_ARG_POINTER(aOptions);
  NS_ASSERTION(aResults->Count() == 0, "Initial result array must be empty");
  if (! aQueries.Count())
    return NS_ERROR_INVALID_ARG;

  nsCString queryString;
  PRBool paramsPresent = PR_FALSE;
  nsNavHistory::StringHash addParams;
  addParams.Init(MAX_HISTORY_DAYS+1);
  nsresult rv = ConstructQueryString(aQueries, aOptions, queryString, 
                                     paramsPresent, addParams);
  NS_ENSURE_SUCCESS(rv,rv);

#ifdef DEBUG_thunder
  printf("Constructed the query: %s\n", PromiseFlatCString(queryString).get());
#endif

  // Put this in a transaction. Even though we are only reading, this will
  // speed up the grouped queries to the annotation service for titles and
  // full text searching.
  mozStorageTransaction transaction(mDBConn, PR_FALSE);

  // create statement
  nsCOMPtr<mozIStorageStatement> statement;
  rv = mDBConn->CreateStatement(queryString, getter_AddRefs(statement));
  NS_ENSURE_SUCCESS(rv, rv);

  if (paramsPresent) {
    // bind parameters
    PRInt32 i;
    for (i = 0; i < aQueries.Count(); i++) {
      rv = BindQueryClauseParameters(statement, i, aQueries[i], aOptions);
      NS_ENSURE_SUCCESS(rv, rv);
    }
  }

  addParams.EnumerateRead(BindAdditionalParameter, statement.get());

  // optimize the case where we just use the results as is
  // and we don't need to do any post-query filtering
  if (NeedToFilterResultSet(aQueries, aOptions)) {
    // generate the toplevel results
    nsCOMArray<nsNavHistoryResultNode> toplevel;
    rv = ResultsAsList(statement, aOptions, &toplevel);
    NS_ENSURE_SUCCESS(rv, rv);

    FilterResultSet(aResultNode, toplevel, aResults, aQueries, aOptions);
  } else {
    rv = ResultsAsList(statement, aOptions, aResults);
    NS_ENSURE_SUCCESS(rv, rv);
  } 

  return NS_OK;
}

// nsNavHistory::AddObserver

NS_IMETHODIMP
nsNavHistory::AddObserver(nsINavHistoryObserver* aObserver, PRBool aOwnsWeak)
{
  return mObservers.AppendWeakElement(aObserver, aOwnsWeak);
}


// nsNavHistory::RemoveObserver

NS_IMETHODIMP
nsNavHistory::RemoveObserver(nsINavHistoryObserver* aObserver)
{
  return mObservers.RemoveWeakElement(aObserver);
}

// nsNavHistory::BeginUpdateBatch
// See RunInBatchMode
nsresult
nsNavHistory::BeginUpdateBatch()
{
  if (mBatchLevel++ == 0) {
    PRBool transactionInProgress = PR_TRUE; // default to no transaction on err
    mDBConn->GetTransactionInProgress(&transactionInProgress);
    mBatchHasTransaction = ! transactionInProgress;
    if (mBatchHasTransaction)
      mDBConn->BeginTransaction();

    ENUMERATE_WEAKARRAY(mObservers, nsINavHistoryObserver,
                        OnBeginUpdateBatch())
  }
  return NS_OK;
}

// nsNavHistory::EndUpdateBatch
nsresult
nsNavHistory::EndUpdateBatch()
{
  if (--mBatchLevel == 0) {
    if (mBatchHasTransaction)
      mDBConn->CommitTransaction();
    mBatchHasTransaction = PR_FALSE;
    ENUMERATE_WEAKARRAY(mObservers, nsINavHistoryObserver, OnEndUpdateBatch())
  }
  return NS_OK;
}

NS_IMETHODIMP
nsNavHistory::RunInBatchMode(nsINavHistoryBatchCallback* aCallback,
                             nsISupports* aUserData) 
{
  NS_ENSURE_ARG_POINTER(aCallback);

  UpdateBatchScoper batch(*this);
  return aCallback->RunBatched(aUserData);
}

NS_IMETHODIMP
nsNavHistory::GetHistoryDisabled(PRBool *_retval)
{
  NS_ENSURE_ARG_POINTER(_retval);
  *_retval = IsHistoryDisabled();
  return NS_OK;
}

// Browser history *************************************************************


// nsNavHistory::AddPageWithDetails
//
//    This function is used by the migration components to import history.
//
//    Note that this always adds the page with one visit and no parent, which
//    is appropriate for imported URIs.

NS_IMETHODIMP
nsNavHistory::AddPageWithDetails(nsIURI *aURI, const PRUnichar *aTitle,
                                 PRInt64 aLastVisited)
{
  PRInt64 visitID;
  nsresult rv = AddVisit(aURI, aLastVisited, 0, TRANSITION_LINK, PR_FALSE,
                         0, &visitID);
  NS_ENSURE_SUCCESS(rv, rv);

  return SetPageTitleInternal(aURI, nsString(aTitle));
}


// nsNavHistory::GetLastPageVisited
//
//    This was once used when the new window is set to "previous page." It
//    doesn't seem to be used anymore, so we don't spend any time precompiling
//    the statement.

NS_IMETHODIMP
nsNavHistory::GetLastPageVisited(nsACString & aLastPageVisited)
{
  nsCOMPtr<mozIStorageStatement> statement;
  nsresult rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.url "
      "FROM moz_places h LEFT OUTER JOIN moz_historyvisits v ON h.id = v.place_id "
      "WHERE v.visit_date IN "
      "(SELECT MAX(visit_date) "
       "FROM moz_historyvisits v2 LEFT JOIN moz_places h2 ON v2.place_id = h2.id "
        "WHERE h2.hidden != 1)"),
    getter_AddRefs(statement));
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasMatch = PR_FALSE;
  if (NS_SUCCEEDED(statement->ExecuteStep(&hasMatch)) && hasMatch) {
    return statement->GetUTF8String(0, aLastPageVisited);
  }
  aLastPageVisited.Truncate(0);
  return NS_OK;
}


// nsNavHistory::GetCount
//
//    This function is used in legacy code to see if there is any history to
//    clear. Counting the actual number of history entries is very slow, so
//    we just see if there are any and return 0 or 1, which is enough to make
//    all the code that uses this function happy.

NS_IMETHODIMP
nsNavHistory::GetCount(PRUint32 *aCount)
{
  PRBool hasEntries = PR_FALSE;
  nsresult rv = GetHasHistoryEntries(&hasEntries);
  if (hasEntries)
    *aCount = 1;
  else
    *aCount = 0;
  return rv;
}


// nsNavHistory::RemovePagesInternal
//
//    Deletes a list of placeIds from history.
//    This is an internal method used by RemovePages and RemovePagesFromHost.
//    Takes a comma separated list of place ids.
//    This method does not do any observer notification.

nsresult
nsNavHistory::RemovePagesInternal(const nsCString& aPlaceIdsQueryString)
{
  // early return if there is nothing to delete
  if (aPlaceIdsQueryString.IsEmpty())
    return NS_OK;

  mozStorageTransaction transaction(mDBConn, PR_FALSE);

  // if a moz_place is annotated or was a bookmark,
  // we won't delete it, but we will delete the moz_visits
  // so we need to reset the frecency.  Note, we set frecency to
  // -visit_count, as we use that value in our "on idle" query
  // to figure out which places to recalculate frecency first.
  // Pay attention to not set frecency = 0 if visit_count = 0
  nsresult rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "UPDATE moz_places "
      "SET frecency = -MAX(visit_count, 1) "
      "WHERE id IN(") +
        aPlaceIdsQueryString +
        NS_LITERAL_CSTRING(") AND ("
          "EXISTS (SELECT b.id FROM moz_bookmarks b WHERE b.fk = moz_places.id) "
          "OR EXISTS "
            "(SELECT a.id FROM moz_annos a WHERE a.place_id = moz_places.id))"));
  NS_ENSURE_SUCCESS(rv, rv);

  // delete all visits
  rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DELETE FROM moz_historyvisits WHERE place_id IN (") +
        aPlaceIdsQueryString +
        NS_LITERAL_CSTRING(")"));
  NS_ENSURE_SUCCESS(rv, rv);

  // now that visits have been removed, run annotation expiration.
  // this will remove all expire-able annotations for these URIs.
  (void)mExpire.OnDeleteURI();

  // if the entry is not bookmarked and is not a place: uri
  // then we can remove it from moz_places.
  // Note that we do NOT delete favicons. Any unreferenced favicons will be
  // deleted next time the browser is shut down.
  rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DELETE FROM moz_places WHERE id IN ("
        "SELECT h.id FROM moz_places h WHERE h.id IN (") +
        aPlaceIdsQueryString +
        NS_LITERAL_CSTRING(") AND "
        "NOT EXISTS (SELECT b.id FROM moz_bookmarks b WHERE b.fk = h.id LIMIT 1) "
        "AND SUBSTR(h.url,0,6) <> 'place:')"));
  NS_ENSURE_SUCCESS(rv, rv);

  // placeId could have a livemark item, so setting the frecency to -1
  // would cause it to show up in the url bar autocomplete
  // call FixInvalidFrecenciesForExcludedPlaces() to handle that scenario
  // XXX this might be dog slow, further degrading delete perf.
  rv = FixInvalidFrecenciesForExcludedPlaces();
  NS_ENSURE_SUCCESS(rv, rv);

  // XXX todo
  // forcibly call the "on idle" timer here to do a little work
  // but the rest will happen on idle.

  return transaction.Commit();
}


// nsNavHistory::RemovePages
//
//    Removes a bunch of uris from history.
//    Has better performance than RemovePage when deleting a lot of history.
//    Notice that this function does not call the onDeleteURI observers,
//    instead, if aDoBatchNotify is true, we call OnBegin/EndUpdateBatch.
//    We don't do duplicates removal, URIs array should be cleaned-up before.

NS_IMETHODIMP
nsNavHistory::RemovePages(nsIURI **aURIs, PRUint32 aLength, PRBool aDoBatchNotify)
{
  nsresult rv;
  // build a list of place ids to delete
  nsCString deletePlaceIdsQueryString;
  for (PRUint32 i = 0; i < aLength; i++) {
    PRInt64 placeId;
    rv = GetUrlIdFor(aURIs[i], &placeId, PR_FALSE);
    NS_ENSURE_SUCCESS(rv, rv);
    if (placeId != 0) {
      if (!deletePlaceIdsQueryString.IsEmpty())
        deletePlaceIdsQueryString.AppendLiteral(",");
      deletePlaceIdsQueryString.AppendInt(placeId);
    }
  }

  rv = RemovePagesInternal(deletePlaceIdsQueryString);
  NS_ENSURE_SUCCESS(rv, rv);

  // force a full refresh calling onEndUpdateBatch (will call Refresh())
  if (aDoBatchNotify)
    UpdateBatchScoper batch(*this); // sends Begin/EndUpdateBatch to observers

  return NS_OK;
}


// nsNavHistory::RemovePage
//
//    Removes all visits and the main history entry for the given URI.
//    Silently fails if we have no knowledge of the page.

 NS_IMETHODIMP
nsNavHistory::RemovePage(nsIURI *aURI)
{
  nsIURI** URIs = &aURI;
  nsresult rv = RemovePages(URIs, 1, PR_FALSE);
  NS_ENSURE_SUCCESS(rv, rv);
  // call observers here for the removed url
  ENUMERATE_WEAKARRAY(mObservers, nsINavHistoryObserver, OnDeleteURI(aURI))
  return NS_OK;
}


// nsNavHistory::RemovePagesFromHost
//
//    This function will delete all history information about pages from a
//    given host. If aEntireDomain is set, we will also delete pages from
//    sub hosts (so if we are passed in "microsoft.com" we delete
//    "www.microsoft.com", "msdn.microsoft.com", etc.). An empty host name
//    means local files and anything else with no host name. You can also pass
//    in the localized "(local files)" title given to you from a history query.
//
//    Silently fails if we have no knowledge of the host.
//
//    This sends onBeginUpdateBatch/onEndUpdateBatch to observers

NS_IMETHODIMP
nsNavHistory::RemovePagesFromHost(const nsACString& aHost, PRBool aEntireDomain)
{
  nsresult rv;
  // Local files don't have any host name. We don't want to delete all files in
  // history when we get passed an empty string, so force to exact match
  if (aHost.IsEmpty())
    aEntireDomain = PR_FALSE;

  // translate "(local files)" to an empty host name
  // be sure to use the TitleForDomain to get the localized name
  nsCString localFiles;
  TitleForDomain(EmptyCString(), localFiles);
  nsAutoString host16;
  if (!aHost.Equals(localFiles))
    host16 = NS_ConvertUTF8toUTF16(aHost);

  // nsISupports version of the host string for passing to observers
  nsCOMPtr<nsISupportsString> hostSupports(do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID, &rv));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = hostSupports->SetData(host16);
  NS_ENSURE_SUCCESS(rv, rv);

  // see BindQueryClauseParameters for how this host selection works
  nsAutoString revHostDot;
  GetReversedHostname(host16, revHostDot);
  NS_ASSERTION(revHostDot[revHostDot.Length() - 1] == '.', "Invalid rev. host");
  nsAutoString revHostSlash(revHostDot);
  revHostSlash.Truncate(revHostSlash.Length() - 1);
  revHostSlash.Append(NS_LITERAL_STRING("/"));

  // build condition string based on host selection type
  nsCAutoString conditionString;
  if (aEntireDomain)
    conditionString.AssignLiteral("h.rev_host >= ?1 AND h.rev_host < ?2 ");
  else
    conditionString.AssignLiteral("h.rev_host = ?1 ");

  nsCOMPtr<mozIStorageStatement> statement;

  // create statement depending on delete type
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id FROM moz_places h WHERE ") +
      conditionString, getter_AddRefs(statement));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = statement->BindStringParameter(0, revHostDot);
  NS_ENSURE_SUCCESS(rv, rv);
  if (aEntireDomain) {
    rv = statement->BindStringParameter(1, revHostSlash);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  nsCString hostPlaceIds;
  PRBool hasMore = PR_FALSE;
  while ((statement->ExecuteStep(&hasMore) == NS_OK) && hasMore) {
    if (!hostPlaceIds.IsEmpty())
      hostPlaceIds.AppendLiteral(",");
    PRInt64 placeId;
    rv = statement->GetInt64(0, &placeId);
    NS_ENSURE_SUCCESS(rv, rv);
    hostPlaceIds.AppendInt(placeId);
  }

  rv = RemovePagesInternal(hostPlaceIds);
  NS_ENSURE_SUCCESS(rv, rv);

  // force a full refresh calling onEndUpdateBatch (will call Refresh())
  UpdateBatchScoper batch(*this); // sends Begin/EndUpdateBatch to observers

  return NS_OK;
}


// nsNavHistory::RemovePagesByTimeframe
//
//    This function will delete all history information about
//    pages for a given timeframe.
//    Limits are included: aBeginTime <= timeframe <= aEndTime
//
//    This method sends onBeginUpdateBatch/onEndUpdateBatch to observers

NS_IMETHODIMP
nsNavHistory::RemovePagesByTimeframe(PRTime aBeginTime, PRTime aEndTime)
{
  nsresult rv;
  // build a list of place ids to delete
  nsCString deletePlaceIdsQueryString;

  // we only need to know if a place has a visit into the given timeframe
  // this query is faster than actually selecting in moz_historyvisits
  nsCOMPtr<mozIStorageStatement> selectByTime;
  rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT h.id FROM moz_places h WHERE "
      "EXISTS (SELECT id FROM moz_historyvisits v WHERE v.place_id = h.id "
      " AND v.visit_date >= ?1 AND v.visit_date <= ?2 LIMIT 1)"),
    getter_AddRefs(selectByTime));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = selectByTime->BindInt64Parameter(0, aBeginTime);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = selectByTime->BindInt64Parameter(1, aEndTime);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasMore = PR_FALSE;
  while (NS_SUCCEEDED(selectByTime->ExecuteStep(&hasMore)) && hasMore) {
    PRInt64 placeId;
    rv = selectByTime->GetInt64(0, &placeId);
    NS_ENSURE_SUCCESS(rv, rv);
    if (placeId != 0) {
      if (!deletePlaceIdsQueryString.IsEmpty())
        deletePlaceIdsQueryString.AppendLiteral(",");
      deletePlaceIdsQueryString.AppendInt(placeId);
    }
  }

  rv = RemovePagesInternal(deletePlaceIdsQueryString);
  NS_ENSURE_SUCCESS(rv, rv);

  // force a full refresh calling onEndUpdateBatch (will call Refresh())
  UpdateBatchScoper batch(*this); // sends Begin/EndUpdateBatch to observers

  return NS_OK;
}


// nsNavHistory::RemoveAllPages
//
//    This function is used to clear history.

NS_IMETHODIMP
nsNavHistory::RemoveAllPages()
{
  // expire everything
  mExpire.ClearHistory();

  // Compress DB. Currently commented out because compression is very slow.
  // Deleted data will be overwritten with 0s by sqlite.
#if 0
  nsresult rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("VACUUM"));
  NS_ENSURE_SUCCESS(rv, rv);
#endif

  // privacy cleanup, if there's an old history.dat around, just delete it
  nsCOMPtr<nsIFile> oldHistoryFile;
  nsresult rv = NS_GetSpecialDirectory(NS_APP_HISTORY_50_FILE,
                                       getter_AddRefs(oldHistoryFile));
  if (NS_FAILED(rv)) return rv;

  PRBool fileExists;
  if (NS_SUCCEEDED(oldHistoryFile->Exists(&fileExists)) && fileExists) {
    rv = oldHistoryFile->Remove(PR_FALSE);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}


// nsNavHistory::HidePage
//
//    Sets the 'hidden' column to true. If we've not heard of the page, we
//    succeed and do nothing.

NS_IMETHODIMP
nsNavHistory::HidePage(nsIURI *aURI)
{
  return NS_ERROR_NOT_IMPLEMENTED;
  /*
  // for speed to save disk accesses
  mozStorageTransaction transaction(mDBConn, PR_FALSE,
                                  mozIStorageConnection::TRANSACTION_EXCLUSIVE);

  // We need to do a query anyway to see if this URL is already in the DB.
  // Might as well ask for the hidden column to save updates in some cases.
  nsCOMPtr<mozIStorageStatement> dbSelectStatement;
  nsresult rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING("SELECT id,hidden FROM moz_places WHERE url = ?1"),
      getter_AddRefs(dbSelectStatement));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = BindStatementURI(dbSelectStatement, 0, aURI);
  NS_ENSURE_SUCCESS(rv, rv);
  PRBool alreadyVisited = PR_TRUE;
  rv = dbSelectStatement->ExecuteStep(&alreadyVisited);
  NS_ENSURE_SUCCESS(rv, rv);

  // don't need to do anything if we've never heard of this page
  if (!alreadyVisited)
    return NS_OK;
 
  // modify the existing page if necessary

  PRInt32 oldHiddenState = 0;
  rv = dbSelectStatement->GetInt32(1, &oldHiddenState);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!oldHiddenState)
    return NS_OK; // already marked as hidden, we're done

  // find the old ID, which can be found faster than long URLs
  PRInt32 entryid = 0;
  rv = dbSelectStatement->GetInt32(0, &entryid);
  NS_ENSURE_SUCCESS(rv, rv);

  // need to clear the old statement before we create a new one
  dbSelectStatement = nsnull;

  nsCOMPtr<mozIStorageStatement> dbModStatement;
  rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING("UPDATE moz_places SET hidden = 1 WHERE id = ?1"),
      getter_AddRefs(dbModStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  dbModStatement->BindInt32Parameter(0, entryid);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = dbModStatement->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  // notify observers, finish transaction first
  transaction.Commit();
  ENUMERATE_WEAKARRAY(mObservers, nsINavHistoryObserver,
                      OnPageChanged(aURI,
                                    nsINavHistoryObserver::ATTRIBUTE_HIDDEN,
                                    EmptyString()))

  return NS_OK;
  */
}


// nsNavHistory::MarkPageAsTyped
//
// We call MarkPageAsTyped() before visiting a URL in order to 
// help determine the transition type of the visit.  
// We keep track of the URL so that later, in AddVisitChain() 
// we can use TRANSITION_TYPED as the transition.
// Note, AddVisitChain() is not called immediately when we are doing LAZY_ADDs
//
// @see MarkPageAsFollowedBookmark

NS_IMETHODIMP
nsNavHistory::MarkPageAsTyped(nsIURI *aURI)
{
  // don't add when history is disabled
  if (IsHistoryDisabled())
    return NS_OK;

  nsCAutoString uriString;
  nsresult rv = aURI->GetSpec(uriString);
  NS_ENSURE_SUCCESS(rv, rv);

  // if URL is already in the typed queue, then we need to remove the old one
  PRInt64 unusedEventTime;
  if (mRecentTyped.Get(uriString, &unusedEventTime))
    mRecentTyped.Remove(uriString);

  if (mRecentTyped.Count() > RECENT_EVENT_QUEUE_MAX_LENGTH)
    ExpireNonrecentEvents(&mRecentTyped);

  mRecentTyped.Put(uriString, GetNow());
  return NS_OK;
}


// nsNavHistory::SetCharsetForURI
//
// Sets the character-set for an URI.
// If aCharset is empty remove character-set annotation for aURI.

NS_IMETHODIMP
nsNavHistory::SetCharsetForURI(nsIURI* aURI,
                               const nsAString& aCharset)
{
  nsAnnotationService* annosvc = nsAnnotationService::GetAnnotationService();
  NS_ENSURE_TRUE(annosvc, NS_ERROR_OUT_OF_MEMORY);

  if (aCharset.IsEmpty()) {
    // remove the current page character-set annotation
    nsresult rv = annosvc->RemovePageAnnotation(aURI, CHARSET_ANNO);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  else {
    // Set page character-set annotation, silently overwrite if already exists
    nsresult rv = annosvc->SetPageAnnotationString(aURI, CHARSET_ANNO,
                                                   aCharset, 0,
                                                   nsAnnotationService::EXPIRE_NEVER);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}


// nsNavHistory::GetCharsetForURI
//
// Get the last saved character-set for an URI.

NS_IMETHODIMP
nsNavHistory::GetCharsetForURI(nsIURI* aURI, 
                               nsAString& aCharset)
{
  nsAnnotationService* annosvc = nsAnnotationService::GetAnnotationService();
  NS_ENSURE_TRUE(annosvc, NS_ERROR_OUT_OF_MEMORY);

  nsAutoString charset;
  nsresult rv = annosvc->GetPageAnnotationString(aURI, CHARSET_ANNO, aCharset);
  if (NS_FAILED(rv)) {
    // be sure to return an empty string if character-set is not found
    aCharset.Truncate();
  }
  return NS_OK;
}


// nsGlobalHistory2 ************************************************************


// nsNavHistory::AddURI
//
//    This is the main method of adding history entries.

NS_IMETHODIMP
nsNavHistory::AddURI(nsIURI *aURI, PRBool aRedirect,
                     PRBool aToplevel, nsIURI *aReferrer)
{
  // don't add when history is disabled
  if (IsHistoryDisabled())
    return NS_OK;

  // filter out any unwanted URIs
  PRBool canAdd = PR_FALSE;
  nsresult rv = CanAddURI(aURI, &canAdd);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!canAdd)
    return NS_OK;

  PRTime now = PR_Now();

#ifdef LAZY_ADD
  LazyMessage message;
  rv = message.Init(LazyMessage::Type_AddURI, aURI);
  NS_ENSURE_SUCCESS(rv, rv);
  message.isRedirect = aRedirect;
  message.isToplevel = aToplevel;
  if (aReferrer) {
    rv = aReferrer->Clone(getter_AddRefs(message.referrer));
    NS_ENSURE_SUCCESS(rv, rv);
  }
  message.time = now;
  rv = AddLazyMessage(message);
  NS_ENSURE_SUCCESS(rv, rv);
#else
  rv = AddURIInternal(aURI, now, aRedirect, aToplevel, aReferrer);
  NS_ENSURE_SUCCESS(rv, rv);
#endif

  mExpire.OnAddURI(now);

  return NS_OK;
}


// nsNavHistory::AddURIInternal
//
//    This does the work of AddURI so it can be done lazily.

nsresult
nsNavHistory::AddURIInternal(nsIURI* aURI, PRTime aTime, PRBool aRedirect,
                             PRBool aToplevel, nsIURI* aReferrer)
{
  mozStorageTransaction transaction(mDBConn, PR_FALSE);

  PRInt64 redirectBookmark = 0;
  PRInt64 visitID, sessionID;
  nsresult rv = AddVisitChain(aURI, aTime, aToplevel, aRedirect, aReferrer,
                              &visitID, &sessionID, &redirectBookmark);
  NS_ENSURE_SUCCESS(rv, rv);

  // The bookmark cache of redirects may be out-of-date with this addition, so
  // we need to update it. The issue here is if they bookmark "mozilla.org" by
  // typing it in without ever having visited "www.mozilla.org". They will then
  // get redirected to the latter, and we need to add mozilla.org ->
  // www.mozilla.org to the bookmark hashtable.
  //
  // AddVisitChain will put the spec of a bookmarked URI if it encounters one
  // into bookmarkURI. If this is non-empty, we know that something has happened
  // with a bookmark and we should probably go update it.
  if (redirectBookmark) {
    nsNavBookmarks* bookmarkService = nsNavBookmarks::GetBookmarksService();
    if (bookmarkService) {
      PRTime now = GetNow();
      bookmarkService->AddBookmarkToHash(redirectBookmark,
                                         now - BOOKMARK_REDIRECT_TIME_THRESHOLD);
    }
  }

  return transaction.Commit();
}


// nsNavHistory::AddVisitChain
//
//    This function is sits between AddURI (which is called when a page is
//    visited) and AddVisit (which creates the DB entries) to figure out what
//    we should add and what are the detailed parameters that should be used
//    (like referring visit ID and typed/bookmarked state).
//
//    This function walks up the referring chain and recursively calls itself,
//    each time calling InternalAdd to create a new history entry. (When we
//    get notified of redirects, we don't actually add any history entries, just
//    save them in mRecentRedirects. This function will add all of them for a
//    given destination page when that page is actually visited.)
//    See GetRedirectFor for more information about how redirects work.
//
//    aRedirectBookmark should be empty when this function is first called. If
//    there are any redirects that are bookmarks the specs will be placed in
//    this buffer. The caller can then determine if any bookmarked items were
//    visited so it knows whether to update the bookmark service's redirect
//    hashtable.

nsresult
nsNavHistory::AddVisitChain(nsIURI* aURI, PRTime aTime,
                            PRBool aToplevel, PRBool aIsRedirect,
                            nsIURI* aReferrerURI, PRInt64* aVisitID,
                            PRInt64* aSessionID, PRInt64* aRedirectBookmark)
{
  PRUint32 transitionType = 0;
  PRInt64 referringVisit = 0;
  PRTime visitTime = 0;
  nsCOMPtr<nsIURI> fromVisitURI = aReferrerURI;

  nsCAutoString spec;
  nsresult rv = aURI->GetSpec(spec);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCAutoString redirectSource;
  if (GetRedirectFor(spec, redirectSource, &visitTime, &transitionType)) {
    // this was a redirect: See GetRedirectFor for info on how this works
    nsCOMPtr<nsIURI> redirectURI;
    rv = NS_NewURI(getter_AddRefs(redirectURI), redirectSource);
    NS_ENSURE_SUCCESS(rv, rv);

    // remember if any redirect sources were bookmarked
    nsNavBookmarks* bookmarkService = nsNavBookmarks::GetBookmarksService();
    PRBool isBookmarked;
    if (bookmarkService &&
        NS_SUCCEEDED(bookmarkService->IsBookmarked(redirectURI, &isBookmarked))
        && isBookmarked) {
      GetUrlIdFor(redirectURI, aRedirectBookmark, PR_FALSE);
    }

    // Find the visit for the source. Note that we decrease the time counter,
    // which will ensure that the referrer and this page will appear in history
    // in the correct order. Since the times are in microseconds, it should not
    // normally be possible to get two pages within one microsecond of each
    // other so the referrer won't appear before a previous page viewed.
    rv = AddVisitChain(redirectURI, aTime - 1, aToplevel, PR_TRUE, aReferrerURI,
                       &referringVisit, aSessionID, aRedirectBookmark);
    NS_ENSURE_SUCCESS(rv, rv);

    // for redirects in frames, we don't want to see those items in history
    // see bug #381453 for more details
    if (!aToplevel) {
      transitionType = nsINavHistoryService::TRANSITION_EMBED;
    }

    // We have been redirected, update the referrer so we can walk up
    // the redirect chain. See bug 411966 for details.
    fromVisitURI = redirectURI;
  } else if (aReferrerURI) {
    // We do not want to add a new visit if the referring site is the same as
    // the new site.  This is the situation where a page refreshes itself to
    // give the user updated information.
    PRBool referrerIsSame;
    if (NS_SUCCEEDED(aURI->Equals(aReferrerURI, &referrerIsSame)) && referrerIsSame)
      return NS_OK;

    // If there is a referrer, we know you came from somewhere, either manually
    // or automatically. For toplevel windows, assume its manual and you want
    // to see this in history. For other things, it's some kind of embedded
    // navigation. This is true of images and other content the user doesn't
    // want to see in their history, but also of embedded frames that the user
    // navigated manually and probably DOES want to see in history.
    // Unfortunately, there isn't any easy way to distinguish these.
    //
    // Generally, it boils down to the problem of detecting whether a frame
    // content change is the result of a user action, which isn't well defined
    // since script could change a frame's source as a result of user request,
    // or just because it feels like loading a new ad. The "back" button will
    // undo either of these actions.
    if (aToplevel)
      transitionType = nsINavHistoryService::TRANSITION_LINK;
    else
      transitionType = nsINavHistoryService::TRANSITION_EMBED;

    // Note that here we should NOT use the GetNow function. That function
    // caches the value of "now" until next time the event loop runs. This
    // gives better performance, but here we may get many notifications without
    // running the event loop. We must preserve these events' ordering. This
    // most commonly happens on redirects.
    visitTime = PR_Now();

    // Try to turn the referrer into a visit.
    // This also populates the session id.
    if (!FindLastVisit(aReferrerURI, &referringVisit, aSessionID)) {
      // we couldn't find a visit for the referrer, don't set it
      *aSessionID = GetNewSessionID();
    }
  } else {
    // When there is no referrer, we know the user must have gotten the link
    // from somewhere, so check our sources to see if it was recently typed or
    // has a bookmark selected. We don't handle drag-and-drop operations.
    // note:  the link may have also come from a new window (set to load a homepage)
    // or on start up (if we've set to load the home page or restore tabs)
    // we treat these as TRANSITION_LINK (if they are top level) or
    // TRANSITION_EMBED (if not top level).  We don't want to to add visits to 
    // history without a transition type.
    if (CheckIsRecentEvent(&mRecentTyped, spec))
      transitionType = nsINavHistoryService::TRANSITION_TYPED;
    else if (CheckIsRecentEvent(&mRecentBookmark, spec))
      transitionType = nsINavHistoryService::TRANSITION_BOOKMARK;
    else if (aToplevel)
      transitionType = nsINavHistoryService::TRANSITION_LINK;
    else
      transitionType = nsINavHistoryService::TRANSITION_EMBED;

    visitTime = PR_Now();
    *aSessionID = GetNewSessionID();
  }

  // this call will create the visit and create/update the page entry
  return AddVisit(aURI, visitTime, fromVisitURI, transitionType,
                  aIsRedirect, *aSessionID, aVisitID);
}


// nsNavHistory::IsVisited
//
//    Note that this ignores the "hidden" flag. This function just checks if the
//    given page is in the DB for link coloring. The "hidden" flag affects
//    the history list view and autocomplete.

NS_IMETHODIMP
nsNavHistory::IsVisited(nsIURI *aURI, PRBool *_retval)
{
  // if history is disabled, we can optimize
  if (IsHistoryDisabled()) {
    *_retval = PR_FALSE;
    return NS_OK;
  }

  nsCAutoString utf8URISpec;
  nsresult rv = aURI->GetSpec(utf8URISpec);
  NS_ENSURE_SUCCESS(rv, rv);

  *_retval = IsURIStringVisited(utf8URISpec);
  return NS_OK;
}


// nsNavHistory::SetPageTitle
//
//    This sets the page title.
//
//    Note that we do not allow empty real titles and will silently ignore such
//    requests. When a URL is added we give it a default title based on the
//    URL. Most pages provide a title and it gets replaced to something better.
//    Some pages don't: some say <title></title>, and some don't have any title
//    element. In BOTH cases, we get SetPageTitle(URI, ""), but in both cases,
//    our default title is more useful to the user than "(no title)".

NS_IMETHODIMP
nsNavHistory::SetPageTitle(nsIURI* aURI,
                           const nsAString& aTitle)
{
  // if aTitle is empty we want to clear the previous title.
  // We don't want to set it to an empty string, but to a NULL value,
  // so we use SetIsVoid and SetPageTitleInternal will take care of that

#ifdef LAZY_ADD
  LazyMessage message;
  nsresult rv = message.Init(LazyMessage::Type_Title, aURI);
  NS_ENSURE_SUCCESS(rv, rv);
  message.title = aTitle;
  if (aTitle.IsEmpty())
    message.title.SetIsVoid(PR_TRUE);
  return AddLazyMessage(message);
#else
  if (aTitle.IsEmpty()) {
    nsString voidString;
    voidString.SetIsVoid(PR_TRUE);
    return SetPageTitleInternal(aURI, voidString);
  }
  return SetPageTitleInternal(aURI, aTitle);
#endif
}

NS_IMETHODIMP
nsNavHistory::GetPageTitle(nsIURI* aURI, nsAString& aTitle)
{
  aTitle.Truncate(0);

  mozIStorageStatement *statement = DBGetURLPageInfo();
  mozStorageStatementScoper scope(statement);
  nsresult rv = BindStatementURI(statement, 0, aURI);
  NS_ENSURE_SUCCESS(rv, rv);


  PRBool results;
  rv = statement->ExecuteStep(&results);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!results) {
    aTitle.SetIsVoid(PR_TRUE);
    return NS_OK; // not found: return void string
  }

  return statement->GetString(nsNavHistory::kGetInfoIndex_Title, aTitle);
}


// nsNavHistory::GetURIGeckoFlags
//
//    FIXME: should we try to use annotations for this stuff?

NS_IMETHODIMP
nsNavHistory::GetURIGeckoFlags(nsIURI* aURI, PRUint32* aResult)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}


// nsNavHistory::SetURIGeckoFlags
//
//    FIXME: should we try to use annotations for this stuff?

NS_IMETHODIMP
nsNavHistory::SetURIGeckoFlags(nsIURI* aURI, PRUint32 aFlags)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

// nsIGlobalHistory3 ***********************************************************

// nsNavHistory::AddDocumentRedirect
//
//    This adds a redirect mapping from the destination of the redirect to the
//    source, time, and type. This mapping is used by GetRedirectFor when we
//    get a page added to reconstruct the redirects that happened when a page
//    is visited. See GetRedirectFor for more information

// this is the expiration callback function that deletes stale entries
PLDHashOperator PR_CALLBACK nsNavHistory::ExpireNonrecentRedirects(
    nsCStringHashKey::KeyType aKey, RedirectInfo& aData, void* aUserArg)
{
  PRInt64* threshold = reinterpret_cast<PRInt64*>(aUserArg);
  if (aData.mTimeCreated < *threshold)
    return PL_DHASH_REMOVE;
  return PL_DHASH_NEXT;
}

NS_IMETHODIMP
nsNavHistory::AddDocumentRedirect(nsIChannel *aOldChannel,
                                  nsIChannel *aNewChannel,
                                  PRInt32 aFlags,
                                  PRBool aTopLevel)
{
  nsresult rv;
  nsCOMPtr<nsIURI> oldURI, newURI;
  rv = aOldChannel->GetURI(getter_AddRefs(oldURI));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = aNewChannel->GetURI(getter_AddRefs(newURI));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCString oldSpec, newSpec;
  rv = oldURI->GetSpec(oldSpec);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = newURI->GetSpec(newSpec);
  NS_ENSURE_SUCCESS(rv, rv);

  if (mRecentRedirects.Count() > RECENT_EVENT_QUEUE_MAX_LENGTH) {
    // expire out-of-date ones
    PRInt64 threshold = PR_Now() - RECENT_EVENT_THRESHOLD;
    mRecentRedirects.Enumerate(ExpireNonrecentRedirects,
                               reinterpret_cast<void*>(&threshold));
  }

  RedirectInfo info;

  // remove any old entries for this redirect destination
  if (mRecentRedirects.Get(newSpec, &info))
    mRecentRedirects.Remove(newSpec);

  // save the new redirect info
  info.mSourceURI = oldSpec;
  info.mTimeCreated = PR_Now();
  if (aFlags & nsIChannelEventSink::REDIRECT_TEMPORARY)
    info.mType = TRANSITION_REDIRECT_TEMPORARY;
  else
    info.mType = TRANSITION_REDIRECT_PERMANENT;
  mRecentRedirects.Put(newSpec, info);

  return NS_OK;
}

nsresult 
nsNavHistory::OnIdle()
{
  nsresult rv;
  nsCOMPtr<nsIIdleService> idleService =
    do_GetService("@mozilla.org/widget/idleservice;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  PRUint32 idleTime;
  rv = idleService->GetIdleTime(&idleTime);
  NS_ENSURE_SUCCESS(rv, rv);

  // If we've been idle for more than mFrecencyUpdateIdleTime
  // recalculate some frecency values. A value of zero indicates that
  // frecency recalculation on idle is disabled.
  if (mFrecencyUpdateIdleTime && idleTime > mFrecencyUpdateIdleTime)
    (void)RecalculateFrecencies(mNumCalculateFrecencyOnIdle, PR_TRUE);

  // If we've been idle for more than EXPIRE_IDLE_TIME_IN_MSECS
  // keep the expiration engine chugging along.
  // Note: This is done prior to a possible vacuum, to optimize space reduction
  // in the vacuum.
  if (idleTime > EXPIRE_IDLE_TIME_IN_MSECS) {
    PRBool dummy;
    (void)mExpire.ExpireItems(MAX_EXPIRE_RECORDS_ON_IDLE, &dummy);
  }

  // If we've been idle for more than LONG_IDLE_TIME_IN_MSECS
  // perform long-idle tasks.
  if (idleTime > LONG_IDLE_TIME_IN_MSECS) {
    // Do a one-time re-creation of the moz_places.url index (bug 381795)
    // XXX REMOVE ME AFTER BETA2.
    PRBool oldIndexExists = PR_FALSE;
    rv = mDBConn->IndexExists(NS_LITERAL_CSTRING("moz_places_urlindex"), &oldIndexExists);
    NS_ENSURE_SUCCESS(rv, rv);
 
    if (oldIndexExists) {
      // wrap in a transaction for safety and performance
      mozStorageTransaction urlindexTransaction(mDBConn, PR_FALSE);
      // drop old index
      rv = mDBConn->ExecuteSimpleSQL(
          NS_LITERAL_CSTRING("DROP INDEX IF EXISTS moz_places_urlindex"));
      NS_ENSURE_SUCCESS(rv, rv);
      // remove any duplicates
      rv = RemoveDuplicateURIs();
      NS_ENSURE_SUCCESS(rv, rv);
      // create new index
      rv = mDBConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("CREATE UNIQUE INDEX moz_places_url_uniqueindex ON moz_places (url)"));
      NS_ENSURE_SUCCESS(rv, rv);
      rv = urlindexTransaction.Commit();
      NS_ENSURE_SUCCESS(rv, rv);
    }

    // detect and replace bogus moz_places_visitcount index
    // see bug 402161
    // XXX REMOVE ME AFTER FINAL
    nsCOMPtr<mozIStorageStatement> detectBogusIndex;
    rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
        "SELECT name FROM sqlite_master WHERE type = 'index' AND "
        "name = 'moz_places_visitcount' AND sql LIKE ?1 ESCAPE '/'"),
        getter_AddRefs(detectBogusIndex));
    NS_ENSURE_SUCCESS(rv, rv);

    nsAutoString escapedString;
    rv = detectBogusIndex->EscapeStringForLIKE(NS_LITERAL_STRING("rev_host"),
                                               '/', escapedString);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = detectBogusIndex->BindStringParameter(0, NS_LITERAL_STRING("%") +
                                                  escapedString +
                                                  NS_LITERAL_STRING("%"));
    NS_ENSURE_SUCCESS(rv, rv);

    PRBool hasResult;
    rv = detectBogusIndex->ExecuteStep(&hasResult);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = detectBogusIndex->Reset();
    NS_ENSURE_SUCCESS(rv, rv);
    if (hasResult) {
      // drop old index
      rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
          "DROP INDEX IF EXISTS moz_places_visitcount"));
      NS_ENSURE_SUCCESS(rv, rv);
      // create new index
      rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
          "CREATE INDEX IF NOT EXISTS moz_places_visitcount "
          "ON moz_places (visit_count)"));
      NS_ENSURE_SUCCESS(rv, rv);
    }

    // Remove dangling livemark annotations
    // we have moved expiration pageAnnotations to itemAnnotations
    // we must remove pageAnnotations to allow expire do the cleanup
    // see bug 388716
    // XXX REMOVE ME AFTER FINAL
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "DELETE FROM moz_annos WHERE id IN (SELECT a.id FROM moz_annos a "
        "JOIN moz_anno_attributes n ON a.anno_attribute_id = n.id "
        "WHERE n.name = 'livemark/expiration')"));
    NS_ENSURE_SUCCESS(rv, rv);

#if 0
    // Currently commented out because vacuum is very slow
    // see bug #390244 for more details.
    rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("VACUUM;"));
    NS_ENSURE_SUCCESS(rv, rv);
#endif
  }
  return NS_OK;
}

void // static
nsNavHistory::IdleTimerCallback(nsITimer* aTimer, void* aClosure)
{
  nsNavHistory* history = static_cast<nsNavHistory*>(aClosure);
  (void)history->OnIdle();
}

// nsIDownloadHistory **********************************************************

NS_IMETHODIMP
nsNavHistory::AddDownload(nsIURI* aSource, nsIURI* aReferrer,
                          PRTime aStartTime)
{
  PRInt64 visitID;
  return AddVisit(aSource, aStartTime, aReferrer, TRANSITION_DOWNLOAD, PR_FALSE,
                  0, &visitID);
}

// nsPIPlacesDatabase **********************************************************

NS_IMETHODIMP
nsNavHistory::GetDBConnection(mozIStorageConnection **_DBConnection)
{
  NS_ADDREF(*_DBConnection = mDBConn);
  return NS_OK;
}

// nsIObserver *****************************************************************

NS_IMETHODIMP
nsNavHistory::Observe(nsISupports *aSubject, const char *aTopic,
                    const PRUnichar *aData)
{
  if (nsCRT::strcmp(aTopic, gQuitApplicationMessage) == 0) {
    if (mIdleTimer) {
      mIdleTimer->Cancel();
      mIdleTimer = nsnull;
    }
    if (mAutoCompleteTimer) {
      mAutoCompleteTimer->Cancel();
      mAutoCompleteTimer = nsnull;
    }
    nsresult rv;
    nsCOMPtr<nsIPrefService> prefService =
      do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
    if (NS_SUCCEEDED(rv))
      prefService->SavePrefFile(nsnull);

    // notify expiring system that we're quitting, it may want to do stuff
    mExpire.OnQuit();

    // run post-run migration
    // NOTE: This must run after expiration. It causes expiration to take a
    // very long time if run first.
    (void)CleanUpOnQuit();

    // notify the bookmarks service we're quitting
    nsNavBookmarks* bookmarks = nsNavBookmarks::GetBookmarksService();
    NS_ENSURE_TRUE(bookmarks, NS_ERROR_OUT_OF_MEMORY);
    (void)bookmarks->OnQuit();
  } else if (nsCRT::strcmp(aTopic, gXpcomShutdown) == 0) {
    nsresult rv;
    nsCOMPtr<nsIObserverService> observerService =
      do_GetService("@mozilla.org/observer-service;1", &rv);
    NS_ENSURE_SUCCESS(rv, rv);
    observerService->RemoveObserver(this, gAutoCompleteFeedback);
    observerService->RemoveObserver(this, gXpcomShutdown);
    observerService->RemoveObserver(this, gQuitApplicationMessage);
  } else if (nsCRT::strcmp(aTopic, gAutoCompleteFeedback) == 0) {
    nsCOMPtr<nsIAutoCompleteInput> input = do_QueryInterface(aSubject);
    if (!input)
      return NS_OK;

    nsCOMPtr<nsIAutoCompletePopup> popup;
    input->GetPopup(getter_AddRefs(popup));
    if (!popup)
      return NS_OK;

    nsCOMPtr<nsIAutoCompleteController> controller;
    input->GetController(getter_AddRefs(controller));
    if (!controller)
      return NS_OK;

    // Don't bother if the popup is closed
    PRBool open;
    nsresult rv = popup->GetPopupOpen(&open);
    NS_ENSURE_SUCCESS(rv, rv);
    if (!open)
      return NS_OK;

    // Ignore if nothing selected from the popup
    PRInt32 selectedIndex;
    rv = popup->GetSelectedIndex(&selectedIndex);
    NS_ENSURE_SUCCESS(rv, rv);
    if (selectedIndex == -1)
      return NS_OK;

    rv = AutoCompleteFeedback(selectedIndex, controller);
    NS_ENSURE_SUCCESS(rv, rv);
  } else if (nsCRT::strcmp(aTopic, "nsPref:changed") == 0) {
    PRInt32 oldDaysMin = mExpireDaysMin;
    PRInt32 oldDaysMax = mExpireDaysMax;
    PRInt32 oldVisits = mExpireSites;
    LoadPrefs(PR_FALSE);
    if (oldDaysMin != mExpireDaysMin || oldDaysMax != mExpireDaysMax ||
        oldVisits != mExpireSites)
      mExpire.OnExpirationChanged();
  }

  return NS_OK;
}


// Lazy stuff ******************************************************************

#ifdef LAZY_ADD

// nsNavHistory::AddLazyLoadFaviconMessage

nsresult
nsNavHistory::AddLazyLoadFaviconMessage(nsIURI* aPage, nsIURI* aFavicon,
                                        PRBool aForceReload)
{
  LazyMessage message;
  nsresult rv = message.Init(LazyMessage::Type_Favicon, aPage);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = aFavicon->Clone(getter_AddRefs(message.favicon));
  NS_ENSURE_SUCCESS(rv, rv);
  message.alwaysLoadFavicon = aForceReload;
  return AddLazyMessage(message);
}


// nsNavHistory::StartLazyTimer
//
//    This schedules flushing of the lazy message queue for the future.
//
//    If we already have timer set, we canel it and schedule a new timer in
//    the future. This saves you from having to wait if you open a bunch of
//    pages in a row. However, we don't want to defer too long, so we'll only
//    push it back MAX_LAZY_TIMER_DEFERMENTS times. After that we always
//    let the timer go the next time.

nsresult
nsNavHistory::StartLazyTimer()
{
  if (! mLazyTimer) {
    mLazyTimer = do_CreateInstance("@mozilla.org/timer;1");
    if (! mLazyTimer)
      return NS_ERROR_OUT_OF_MEMORY;
  } else {
    if (mLazyTimerSet) {
      if (mLazyTimerDeferments >= MAX_LAZY_TIMER_DEFERMENTS) {
        // already set and we don't want to push it back any later, use that one
        return NS_OK;
      } else {
        // push back the active timer
        mLazyTimer->Cancel();
        mLazyTimerDeferments ++;
      }
    }
  }
  nsresult rv = mLazyTimer->InitWithFuncCallback(LazyTimerCallback, this,
                                                 LAZY_MESSAGE_TIMEOUT,
                                                 nsITimer::TYPE_ONE_SHOT);
  NS_ENSURE_SUCCESS(rv, rv);
  mLazyTimerSet = PR_TRUE;
  return NS_OK;
}


// nsNavHistory::AddLazyMessage

nsresult
nsNavHistory::AddLazyMessage(const LazyMessage& aMessage)
{
  if (! mLazyMessages.AppendElement(aMessage))
    return NS_ERROR_OUT_OF_MEMORY;
  return StartLazyTimer();
}


// nsNavHistory::LazyTimerCallback

void // static
nsNavHistory::LazyTimerCallback(nsITimer* aTimer, void* aClosure)
{
  nsNavHistory* that = static_cast<nsNavHistory*>(aClosure);
  that->mLazyTimerSet = PR_FALSE;
  that->mLazyTimerDeferments = 0;
  that->CommitLazyMessages();
}

// nsNavHistory::CommitLazyMessages

void
nsNavHistory::CommitLazyMessages()
{
  mozStorageTransaction transaction(mDBConn, PR_TRUE);
  for (PRUint32 i = 0; i < mLazyMessages.Length(); i ++) {
    LazyMessage& message = mLazyMessages[i];
    switch (message.type) {
      case LazyMessage::Type_AddURI:
        AddURIInternal(message.uri, message.time, message.isRedirect,
                       message.isToplevel, message.referrer);
        break;
      case LazyMessage::Type_Title:
        SetPageTitleInternal(message.uri, message.title);
        break;
      case LazyMessage::Type_Favicon: {
        nsFaviconService* faviconService = nsFaviconService::GetFaviconService();
        if (faviconService) {
          faviconService->DoSetAndLoadFaviconForPage(message.uri,
                                                     message.favicon,
                                                     message.alwaysLoadFavicon);
        }
        break;
      }
      default:
        NS_NOTREACHED("Invalid lazy message type");
    }
  }
  mLazyMessages.Clear();
}
#endif // LAZY_ADD


// Query stuff *****************************************************************

// Helper class for QueryToSelectClause
//
// This class helps to build part of the WHERE clause. It supports 
// multiple queries by appending the query index to the parameter name. 
// For the query with index 0 the parameter name is not altered what
// allows using this parameter in other situations (see SelectAsSite). 

class ConditionBuilder
{
public:

  ConditionBuilder(PRInt32 aQueryIndex): mQueryIndex(aQueryIndex)
  { }

  ConditionBuilder& Condition(const char* aStr)
  {
    if (!mClause.IsEmpty())
      mClause.AppendLiteral(" AND ");
    Str(aStr);
    return *this;
  }

  ConditionBuilder& Str(const char* aStr)
  {
    mClause.Append(' ');
    mClause.Append(aStr);
    mClause.Append(' ');
    return *this;
  }

  ConditionBuilder& Param(const char* aParam)
  {
    mClause.Append(' ');
    if (!mQueryIndex)
      mClause.Append(aParam);
    else
      mClause += nsPrintfCString("%s%d", aParam, mQueryIndex);

    mClause.Append(' ');
    return *this;
  }

  void GetClauseString(nsCString& aResult) 
  {
    aResult = mClause;
  }

private:

  PRInt32 mQueryIndex;
  nsCString mClause;
};


// nsNavHistory::QueryToSelectClause
//
//    THE BEHAVIOR SHOULD BE IN SYNC WITH BindQueryClauseParameters
//
//    I don't check return values from the query object getters because there's
//    no way for those to fail.

nsresult
nsNavHistory::QueryToSelectClause(nsNavHistoryQuery* aQuery, // const
                                  nsNavHistoryQueryOptions* aOptions,
                                  PRInt32 aQueryIndex,
                                  nsCString* aClause)
{
  PRBool hasIt;

  ConditionBuilder clause(aQueryIndex);

  // begin time
  if (NS_SUCCEEDED(aQuery->GetHasBeginTime(&hasIt)) && hasIt) 
    clause.Condition("v.visit_date >=").Param(":begin_time");

  // end time
  if (NS_SUCCEEDED(aQuery->GetHasEndTime(&hasIt)) && hasIt)
    clause.Condition("v.visit_date <=").Param(":end_time");

  // search terms FIXME

  // min and max visit count
  if (aQuery->MinVisits() >= 0)
    clause.Condition("h.visit_count >=").Param(":min_visits");

  if (aQuery->MaxVisits() >= 0)
    clause.Condition("h.visit_count <=").Param(":max_visits");
  
  // only bookmarked, has no affect on bookmarks-only queries
  if (aOptions->QueryType() != nsINavHistoryQueryOptions::QUERY_TYPE_BOOKMARKS &&
      aQuery->OnlyBookmarked())
    clause.Condition("EXISTS (SELECT b.fk FROM moz_bookmarks b WHERE b.type = ")
          .Str(nsPrintfCString("%d", nsNavBookmarks::TYPE_BOOKMARK).get())
          .Str("AND b.fk = h.id)");

  // domain
  if (NS_SUCCEEDED(aQuery->GetHasDomain(&hasIt)) && hasIt) {
    PRBool domainIsHost = PR_FALSE;
    aQuery->GetDomainIsHost(&domainIsHost);
    if (domainIsHost)
      clause.Condition("h.rev_host =").Param(":domain_lower");
    else
      // see domain setting in BindQueryClauseParameters for why we do this
      clause.Condition("h.rev_host >=").Param(":domain_lower")
            .Condition("h.rev_host <").Param(":domain_upper");
  }

  // URI
  //
  // Performance improvement: Selecting URI by prefixes this way is slow because
  // sqlite will not use indices when you use substring. Currently, there is
  // not really any use for URI queries, so this isn't worth optimizing a lot.
  // In the future, we could do a >=,<= thing like we do for domain names to
  // make it use the index.
  if (NS_SUCCEEDED(aQuery->GetHasUri(&hasIt)) && hasIt) {
    if (aQuery->UriIsPrefix())
      clause.Condition("SUBSTR(h.url, 0, LENGTH(").Param(":uri").Str(")) =")
            .Param(":uri");
    else
      clause.Condition("h.url =").Param(":uri");
  }

  // annotation
  aQuery->GetHasAnnotation(&hasIt);
  if (hasIt) {
    clause.Condition("");
    if (aQuery->AnnotationIsNot())
      clause.Str("NOT");
    clause.Str(
      "EXISTS "
        "(SELECT h.id "
         "FROM moz_annos anno "
              "JOIN moz_anno_attributes annoname "
                "ON anno.anno_attribute_id = annoname.id "
         "WHERE anno.place_id = h.id "
           "AND annoname.name = ").Param(":anno").Str(")");
    // annotation-based queries don't get the common conditions, so you get
    // all URLs with that annotation
  }

  // parent parameter is used in tag contents queries.
  // Only one folder should be defined for them.
  if (aOptions->ResultType() == nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS &&
      aQuery->Folders().Length() == 1) {
    clause.Condition("b.parent =").Param(":parent");
  }

  clause.GetClauseString(*aClause);
  return NS_OK;
}

// Helper class for BindQueryClauseParameters
//
// This class converts parameter names to parameter indexes. It supports 
// multiple queries by appending the query index to the parameter name. 
// For the query with index 0 the parameter name is not altered what
// allows using this parameter in other situations (see SelectAsSite). 

class IndexGetter
{
public:
  IndexGetter(PRInt32 aQueryIndex, mozIStorageStatement* aStatement) : 
    mQueryIndex(aQueryIndex), mStatement(aStatement)
  {
    mResult = NS_OK;
  }

  PRUint32 For(const char* aName) 
  {
    PRUint32 index;

    // Do not execute if we already had an error
    if (NS_SUCCEEDED(mResult)) {
      if (!mQueryIndex)
        mResult = mStatement->GetParameterIndex(nsCAutoString(aName), &index);
      else
        mResult = mStatement->GetParameterIndex(
                      nsPrintfCString("%s%d", aName, mQueryIndex), &index);
    }

    if (NS_SUCCEEDED(mResult))
      return index;

    return -1; // Invalid index
  }

  nsresult Result() 
  {
    return mResult;
  }

private:
  PRInt32 mQueryIndex;
  mozIStorageStatement* mStatement;
  nsresult mResult;
};

// nsNavHistory::BindQueryClauseParameters
//
//    THE BEHAVIOR SHOULD BE IN SYNC WITH QueryToSelectClause

nsresult
nsNavHistory::BindQueryClauseParameters(mozIStorageStatement* statement,
                                        PRInt32 aQueryIndex,
                                        nsNavHistoryQuery* aQuery, // const
                                        nsNavHistoryQueryOptions* aOptions)
{
  nsresult rv;

  PRBool hasIt;
  IndexGetter index(aQueryIndex, statement);

  // begin time
  if (NS_SUCCEEDED(aQuery->GetHasBeginTime(&hasIt)) && hasIt) {
    PRTime time = NormalizeTime(aQuery->BeginTimeReference(),
                                aQuery->BeginTime());
    rv = statement->BindInt64Parameter(index.For(":begin_time"), time);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // end time
  if (NS_SUCCEEDED(aQuery->GetHasEndTime(&hasIt)) && hasIt) {
    PRTime time = NormalizeTime(aQuery->EndTimeReference(),
                                aQuery->EndTime());
    rv = statement->BindInt64Parameter(index.For(":end_time"), time);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // search terms FIXME

  // min and max visit count
  PRInt32 visits = aQuery->MinVisits();
  if (visits >= 0) {
    rv = statement->BindInt32Parameter(index.For(":min_visits"), visits);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  visits = aQuery->MaxVisits();
  if (visits >= 0) {
    rv = statement->BindInt32Parameter(index.For(":max_visits"), visits);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // domain (see GetReversedHostname for more info on reversed host names)
  if (NS_SUCCEEDED(aQuery->GetHasDomain(&hasIt)) && hasIt) {
    nsString revDomain;
    GetReversedHostname(NS_ConvertUTF8toUTF16(aQuery->Domain()), revDomain);

    if (aQuery->DomainIsHost()) {
      rv = statement->BindStringParameter(index.For(":domain_lower"), revDomain);
      NS_ENSURE_SUCCESS(rv, rv);
    } else {
      // for "mozilla.org" do query >= "gro.allizom." AND < "gro.allizom/"
      // which will get everything starting with "gro.allizom." while using the
      // index (using SUBSTRING() causes indexes to be discarded).
      NS_ASSERTION(revDomain[revDomain.Length() - 1] == '.', "Invalid rev. host");
      rv = statement->BindStringParameter(index.For(":domain_lower"), revDomain);
      NS_ENSURE_SUCCESS(rv, rv);
      revDomain.Truncate(revDomain.Length() - 1);
      revDomain.Append(PRUnichar('/'));
      rv = statement->BindStringParameter(index.For(":domain_upper"), revDomain);
      NS_ENSURE_SUCCESS(rv, rv);
    }
  }

  // URI
  if (NS_SUCCEEDED(aQuery->GetHasUri(&hasIt)) && hasIt)
    BindStatementURI(statement, index.For(":uri"), aQuery->Uri());

  // annotation
  if (NS_SUCCEEDED(aQuery->GetHasAnnotation(&hasIt)) && hasIt) {
    rv = statement->BindUTF8StringParameter(index.For(":anno"), 
                                            aQuery->Annotation());
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // parent parameter
  if (aOptions->ResultType() == nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS &&
      aQuery->Folders().Length() == 1) {
    rv = statement->BindInt64Parameter(index.For(":parent"),
                                       aQuery->Folders()[0]);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  NS_ENSURE_SUCCESS(index.Result(), index.Result());

  return NS_OK;
}


// nsNavHistory::ResultsAsList
//

nsresult
nsNavHistory::ResultsAsList(mozIStorageStatement* statement,
                            nsNavHistoryQueryOptions* aOptions,
                            nsCOMArray<nsNavHistoryResultNode>* aResults)
{
  nsresult rv;
  nsCOMPtr<mozIStorageValueArray> row = do_QueryInterface(statement, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasMore = PR_FALSE;
  while (NS_SUCCEEDED(statement->ExecuteStep(&hasMore)) && hasMore) {
    nsRefPtr<nsNavHistoryResultNode> result;
    rv = RowToResult(row, aOptions, getter_AddRefs(result));
    NS_ENSURE_SUCCESS(rv, rv);
    aResults->AppendObject(result);
  }
  return NS_OK;
}

static PRInt64
GetAgeInDays(PRTime aNormalizedNow, PRTime aDate)
{
  PRTime dateMidnight = NormalizeTimeRelativeToday(aDate);
  // if the visit time is in the future
  // treat as "today" see bug #385867
  if (dateMidnight > aNormalizedNow)
    return 0;
  else
    return ((aNormalizedNow - dateMidnight) / USECS_PER_DAY);
}

const PRInt64 UNDEFINED_URN_VALUE = -1;

// Create a urn (like
// urn:places-persist:place:group=0&group=1&sort=1&type=1,,%28local%20files%29)
// to be used to persist the open state of this container in localstore.rdf
nsresult
CreatePlacesPersistURN(nsNavHistoryQueryResultNode *aResultNode, 
                      PRInt64 aValue, const nsCString& aTitle, nsCString& aURN)
{
  nsCAutoString uri;
  nsresult rv = aResultNode->GetUri(uri);
  NS_ENSURE_SUCCESS(rv, rv);

  aURN.Assign(NS_LITERAL_CSTRING("urn:places-persist:"));
  aURN.Append(uri);

  aURN.Append(NS_LITERAL_CSTRING(","));
  if (aValue != UNDEFINED_URN_VALUE)
    aURN.AppendInt(aValue);

  aURN.Append(NS_LITERAL_CSTRING(","));
  if (!aTitle.IsEmpty()) {
    nsCAutoString escapedTitle;
    PRBool success = NS_Escape(aTitle, escapedTitle, url_XAlphas);
    NS_ENSURE_TRUE(success, NS_ERROR_OUT_OF_MEMORY);
    aURN.Append(escapedTitle);
  }

  return NS_OK;
}

PRInt64
nsNavHistory::GetTagsFolder()
{
  // cache our tags folder
  // note, we can't do this in nsNavHistory::Init(), 
  // as getting the bookmarks service would initialize it.
  if (mTagsFolder == -1) {
    nsNavBookmarks* bookmarks = nsNavBookmarks::GetBookmarksService();
    NS_ENSURE_TRUE(bookmarks, -1);
    
    nsresult rv = bookmarks->GetTagsFolder(&mTagsFolder);
    NS_ENSURE_SUCCESS(rv, -1);
  }
  return mTagsFolder;
}

// nsNavHistory::FilterResultSet
//
// This does some post-query-execution filtering:
//   - searching on title & url
//   - parent folder (recursively)
//   - excludeQueries
//   - tags
//   - limit count
//   - excludingLivemarkItems
//
// Note:  changes to filtering in FilterResultSet() 
// may require changes to NeedToFilterResultSet()

nsresult
nsNavHistory::FilterResultSet(nsNavHistoryQueryResultNode* aQueryNode,
                              const nsCOMArray<nsNavHistoryResultNode>& aSet,
                              nsCOMArray<nsNavHistoryResultNode>* aFiltered,
                              const nsCOMArray<nsNavHistoryQuery>& aQueries,
                              nsNavHistoryQueryOptions *aOptions)
{
  nsresult rv;

  // get the bookmarks service
  nsNavBookmarks* bookmarks = nsNavBookmarks::GetBookmarksService();
  NS_ENSURE_TRUE(bookmarks, NS_ERROR_OUT_OF_MEMORY);

  // parse the search terms
  nsTArray<nsStringArray*> terms;
  ParseSearchTermsFromQueries(aQueries, &terms);

  PRInt32 queryIndex;
  PRUint16 resultType = aOptions->ResultType();

  // The includeFolders array for each query is initialized with its
  // query's folders array. We add sub-folders as we check items.
  nsTArray< nsTArray<PRInt64>* > includeFolders;
  nsTArray< nsTArray<PRInt64>* > excludeFolders;
  for (queryIndex = 0;
       queryIndex < aQueries.Count(); queryIndex++) {
    includeFolders.AppendElement(new nsTArray<PRInt64>(aQueries[queryIndex]->Folders()));
    excludeFolders.AppendElement(new nsTArray<PRInt64>());
  }

  // filter against query options
  // XXX only excludeQueries and excludeItemIfParentHasAnnotation are supported at the moment
  PRBool excludeQueries = PR_FALSE;
  if (aQueryNode) {
    rv = aQueryNode->mOptions->GetExcludeQueries(&excludeQueries);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  nsCString parentAnnotationToExclude;
  nsTArray<PRInt64> parentFoldersToExclude;
  if (aQueryNode) {
    rv = aQueryNode->mOptions->GetExcludeItemIfParentHasAnnotation(parentAnnotationToExclude);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  if (!parentAnnotationToExclude.IsEmpty()) {
    // find all the folders that have the annotation we are excluding
    // and save off their item ids. when doing filtering, 
    // if a result's parent item id matches a saved item id, 
    // the result should be excluded
    mozStorageStatementScoper scope(mFoldersWithAnnotationQuery);

    rv = mFoldersWithAnnotationQuery->BindUTF8StringParameter(0, parentAnnotationToExclude);
    NS_ENSURE_SUCCESS(rv, rv);

    PRBool hasMore = PR_FALSE;
    while (NS_SUCCEEDED(mFoldersWithAnnotationQuery->ExecuteStep(&hasMore)) && hasMore) {
      PRInt64 folderId = 0;
      rv = mFoldersWithAnnotationQuery->GetInt64(0, &folderId);
      NS_ENSURE_SUCCESS(rv, rv);
      parentFoldersToExclude.AppendElement(folderId);
    }
  }

  for (PRInt32 nodeIndex = 0; nodeIndex < aSet.Count(); nodeIndex ++) {
    // exclude-queries is implicit when searching, we're only looking at
    // plan URI nodes
    if (!aSet[nodeIndex]->IsURI())
      continue;

    PRInt64 parentId = -1;
    if (aSet[nodeIndex]->mItemId != -1) {
      if (aQueryNode->mItemId == aSet[nodeIndex]->mItemId)
        continue;
      rv = bookmarks->GetFolderIdForItem(aSet[nodeIndex]->mItemId, &parentId);
      NS_ENSURE_SUCCESS(rv, rv);
    }

    // if we are excluding items by parent annotation, 
    // exclude items who's parent is a folder with that annotation
    if (!parentAnnotationToExclude.IsEmpty() && (parentFoldersToExclude.IndexOf(parentId) != -1))
      continue;

    // Append the node if it matches one of the queries
    PRBool appendNode = PR_FALSE;
    for (queryIndex = 0;
         queryIndex < aQueries.Count() && !appendNode; queryIndex++) {
      // parent folder
      // RESULTS_AS_TAG_CONTENTS changes bookmarks parent, so we must not filter
      // this kind of result based on the parent.
      if (includeFolders[queryIndex]->Length() != 0 &&
          resultType != nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS) {
        // filter out simple history nodes from bookmark queries
        if (aSet[nodeIndex]->mItemId == -1)
          continue;

        // filter out the node of which their parent is in the exclude-folders
        // cache
        if (excludeFolders[queryIndex]->IndexOf(parentId) != -1)
          continue;

        if (includeFolders[queryIndex]->IndexOf(parentId) == -1) {
          // check ancestors
          PRInt64 ancestor = parentId, lastAncestor;
          PRBool belongs = PR_FALSE;
          nsTArray<PRInt64> ancestorFolders;

          while (!belongs) {
            // Avoid using |ancestor| itself if GetFolderIdForItem failed.
            lastAncestor = ancestor;
            ancestorFolders.AppendElement(ancestor);

            // GetFolderIdForItems throws when called for the places-root
            if (NS_FAILED(bookmarks->GetFolderIdForItem(ancestor,&ancestor))) {
              break;
            } else if (excludeFolders[queryIndex]->IndexOf(ancestor) != -1) {
              break;
            } else if (includeFolders[queryIndex]->IndexOf(ancestor) != -1) {
              belongs = PR_TRUE;
            }
          }
          // if the parentId or any of its ancestors "belong",
          // include all of them.  otherwise, exclude all of them.
          if (belongs) {
            includeFolders[queryIndex]->AppendElements(ancestorFolders);
          } else {
            excludeFolders[queryIndex]->AppendElements(ancestorFolders);
            continue;
          }
        }
      }

      // Load up the title, url, tags for the current node as UTF16 strings
      NS_ConvertUTF8toUTF16 nodeTitle(aSet[nodeIndex]->mTitle);
      // Unescape the URL for search term matching
      nsCAutoString cNodeURL(aSet[nodeIndex]->mURI);
      NS_ConvertUTF8toUTF16 nodeURL(NS_UnescapeURL(cNodeURL));

      // Fetch the tags
      mozStorageStatementScoper scoper(mDBGetTags);
      rv = mDBGetTags->BindInt32Parameter(0, GetTagsFolder());
      NS_ENSURE_SUCCESS(rv, rv);
      rv = mDBGetTags->BindUTF8StringParameter(1, aSet[nodeIndex]->mURI);
      NS_ENSURE_SUCCESS(rv, rv);

      nsAutoString nodeTags;
      PRBool hasTag = PR_FALSE;
      if (NS_SUCCEEDED(mDBGetTags->ExecuteStep(&hasTag)) && hasTag) {
        rv = mDBGetTags->GetString(0, nodeTags);
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Determine if every search term matches anywhere in the title, url, tag
      PRBool matchAll = PR_TRUE;
      for (PRInt32 termIndex = terms[queryIndex]->Count(); --termIndex >= 0 &&
           matchAll; ) {
        const nsString *term = terms[queryIndex]->StringAt(termIndex);

        // True if any of them match; false makes us quit the loop
        matchAll = CaseInsensitiveFindInReadable(*term, nodeTitle) ||
                   CaseInsensitiveFindInReadable(*term, nodeURL) ||
                   CaseInsensitiveFindInReadable(*term, nodeTags);
      }

      // Skip if we don't match all terms in the title, url or tag
      if (!matchAll)
        continue;

      appendNode = PR_TRUE;
    }

    // RESULTS_AS_TAG_CONTENTS returns a set ordered by place_id and
    // lastModified. So, to remove duplicates, we can retain the first result
    // for each uri.
    if (resultType == nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS &&
        nodeIndex > 0 && aSet[nodeIndex]->mURI == aSet[nodeIndex-1]->mURI)
      continue;

    if (appendNode)
      aFiltered->AppendObject(aSet[nodeIndex]);
      
    // stop once we've seen max results
    if (aOptions->MaxResults() > 0 && 
        aFiltered->Count() >= aOptions->MaxResults())
      break;
  }

  // de-allocate the matrixes
  for (PRUint32 i=0; i < aQueries.Count(); i++) {
    delete terms[i];
    delete includeFolders[i];
    delete excludeFolders[i];
  }

  return NS_OK;
}


// nsNavHistory::CheckIsRecentEvent
//
//    Sees if this URL happened "recently."
//
//    It is always removed from our recent list no matter what. It only counts
//    as "recent" if the event happened more recently than our event
//    threshold ago.

PRBool
nsNavHistory::CheckIsRecentEvent(RecentEventHash* hashTable,
                                 const nsACString& url)
{
  PRTime eventTime;
  if (hashTable->Get(url, &eventTime)) {
    hashTable->Remove(url);
    if (eventTime > GetNow() - RECENT_EVENT_THRESHOLD)
      return PR_TRUE;
    return PR_FALSE;
  }
  return PR_FALSE;
}


// nsNavHistory::ExpireNonrecentEvents
//
//    This goes through our

PR_STATIC_CALLBACK(PLDHashOperator)
ExpireNonrecentEventsCallback(nsCStringHashKey::KeyType aKey,
                              PRInt64& aData,
                              void* userArg)
{
  PRInt64* threshold = reinterpret_cast<PRInt64*>(userArg);
  if (aData < *threshold)
    return PL_DHASH_REMOVE;
  return PL_DHASH_NEXT;
}
void
nsNavHistory::ExpireNonrecentEvents(RecentEventHash* hashTable)
{
  PRInt64 threshold = GetNow() - RECENT_EVENT_THRESHOLD;
  hashTable->Enumerate(ExpireNonrecentEventsCallback,
                       reinterpret_cast<void*>(&threshold));
}


// nsNavHistory::GetRedirectFor
//
//    Given a destination URI, this finds a recent redirect that resulted in
//    this URI. If it finds one, it will put the redirect source info into
//    the out params and return true. If there is no matching redirect, it will
//    return false.
//
//    @param aDestination The destination URI spec of the redirect to look for.
//    @param aSource      Will be filled with the redirect source URI when a
//                        redirect is found.
//    @param aTime        Will be filled with the time the redirect happened
//                         when a redirect is found.
//    @param aRedirectType Will be filled with the redirect type when a redirect
//                         is found. Will be either
//                         TRANSITION_REDIRECT_PERMANENT or
//                         TRANSITION_REDIRECT_TEMPORARY
//    @returns True if the redirect is found.
//
//    HOW REDIRECT TRACKING WORKS
//    ---------------------------
//    When we get an AddDocumentRedirect message, we store the redirect in
//    our mRecentRedirects which maps the destination URI to a source,time pair.
//    When we get a new URI, we see if there were any redirects to this page
//    in the hash table. If found, we know that the page came through the given
//    redirect and add it.
//
//    Example: Page S redirects throught R1, then R2, to give page D. Page S
//    will have been already added to history.
//    - AddDocumentRedirect(R1, R2)
//    - AddDocumentRedirect(R2, D)
//    - AddURI(uri=D, referrer=S)
//
//    When we get the AddURI(D), we see the hash table has a value for D from R2.
//    We have to recursively check that source since there could be more than
//    one redirect, as in this case. Here we see there was a redirect to R2 from
//    R1. The referrer for D is S, so we know S->R1->R2->D.
//
//    Alternatively, the user could have typed or followed a bookmark from S.
//    In this case, with two redirects we'll get:
//    - MarkPageAsTyped(S)
//    - AddDocumentRedirect(S, R)
//    - AddDocumentRedirect(R, D)
//    - AddURI(uri=D, referrer=null)
//    We need to be careful to add a visit to S in this case with an incoming
//    transition of typed and an outgoing transition of redirect.
//
//    Note that this can get confused in some cases where you have a page
//    open in more than one window loading at the same time. This should be rare,
//    however, and should not affect much.

PRBool
nsNavHistory::GetRedirectFor(const nsACString& aDestination,
                             nsACString& aSource, PRTime* aTime,
                             PRUint32* aRedirectType)
{
  RedirectInfo info;
  if (mRecentRedirects.Get(aDestination, &info)) {
    mRecentRedirects.Remove(aDestination);
    if (info.mTimeCreated < GetNow() - RECENT_EVENT_THRESHOLD)
      return PR_FALSE; // too long ago, probably invalid
    aSource = info.mSourceURI;
    *aTime = info.mTimeCreated;
    *aRedirectType = info.mType;
    return PR_TRUE;
  }
  return PR_FALSE;
}


// nsNavHistory::RowToResult
//
//    Here, we just have a generic row. It could be a query, URL, visit,
//    or full visit.

nsresult
nsNavHistory::RowToResult(mozIStorageValueArray* aRow,
                          nsNavHistoryQueryOptions* aOptions,
                          nsNavHistoryResultNode** aResult)
{
  *aResult = nsnull;
  NS_ASSERTION(aRow && aOptions && aResult, "Null pointer in RowToResult");

  // URL
  nsCAutoString url;
  nsresult rv = aRow->GetUTF8String(kGetInfoIndex_URL, url);
  NS_ENSURE_SUCCESS(rv, rv);

  // title
  nsCAutoString title;
  rv = aRow->GetUTF8String(kGetInfoIndex_Title, title);
  NS_ENSURE_SUCCESS(rv, rv);

  PRUint32 accessCount = aRow->AsInt32(kGetInfoIndex_VisitCount);
  PRTime time = aRow->AsInt64(kGetInfoIndex_VisitDate);

  // favicon
  nsCAutoString favicon;
  rv = aRow->GetUTF8String(kGetInfoIndex_FaviconURL, favicon);
  NS_ENSURE_SUCCESS(rv, rv);

  // itemId, if any
  PRInt64 itemId = -1;
  PRBool isNull;
  rv = aRow->GetIsNull(kGetInfoIndex_ItemId, &isNull);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!isNull) {
    itemId = aRow->AsInt64(kGetInfoIndex_ItemId);
  }

  if (IsQueryURI(url)) {
    // special case "place:" URIs: turn them into containers
      
    // We should never expose the history title for query nodes if the
    // bookmark-item's title is set to null (the history title may be the
    // query string without the place: prefix). Thus we call getItemTitle
    // explicitly. Unfortunately, query-bookmarks cannot be distinguished in the
    // sql query.
    if (itemId != -1) {
      nsNavBookmarks* bookmarks = nsNavBookmarks::GetBookmarksService();
      NS_ENSURE_TRUE(bookmarks, NS_ERROR_OUT_OF_MEMORY);

      rv = bookmarks->GetItemTitle(itemId, title);
      NS_ENSURE_SUCCESS(rv, rv);
    }

    rv = QueryRowToResult(itemId, url, title, accessCount, time, favicon, aResult);

    // If it's a simple folder node (i.e. a shortcut to another folder), apply
    // our options for it. However, if the parent type was tag query, we do not
    // apply them, because it would not yield any results.
    if (*aResult && (*aResult)->IsFolder() &&
         aOptions->ResultType() != 
           nsINavHistoryQueryOptions::RESULTS_AS_TAG_QUERY)
      (*aResult)->GetAsContainer()->mOptions = aOptions;

    // RESULTS_AS_TAG_QUERY has date columns
    if (aOptions->ResultType() == nsNavHistoryQueryOptions::RESULTS_AS_TAG_QUERY) {
      (*aResult)->mDateAdded = aRow->AsInt64(kGetInfoIndex_ItemDateAdded);
      (*aResult)->mLastModified = aRow->AsInt64(kGetInfoIndex_ItemLastModified);
    }

    return rv;
  } else if (aOptions->ResultType() == nsNavHistoryQueryOptions::RESULTS_AS_URI ||
             aOptions->ResultType() == nsNavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS) {
    *aResult = new nsNavHistoryResultNode(url, title, accessCount, time,
                                          favicon);
    if (!*aResult)
      return NS_ERROR_OUT_OF_MEMORY;

    if (itemId != -1) {
      (*aResult)->mItemId = itemId;
      (*aResult)->mDateAdded = aRow->AsInt64(kGetInfoIndex_ItemDateAdded);
      (*aResult)->mLastModified = aRow->AsInt64(kGetInfoIndex_ItemLastModified);
    }
    NS_ADDREF(*aResult);
    return NS_OK;
  }
  // now we know the result type is some kind of visit (regular or full)

  // session
  PRInt64 session = aRow->AsInt64(kGetInfoIndex_SessionId);

  if (aOptions->ResultType() == nsNavHistoryQueryOptions::RESULTS_AS_VISIT) {
    *aResult = new nsNavHistoryVisitResultNode(url, title, accessCount, time,
                                               favicon, session);
    if (! *aResult)
      return NS_ERROR_OUT_OF_MEMORY;
    NS_ADDREF(*aResult);
    return NS_OK;
  }

  return NS_ERROR_FAILURE;
}


// nsNavHistory::QueryRowToResult
//
//    Called by RowToResult when the URI is a place: URI to generate the proper
//    folder or query node.

nsresult
nsNavHistory::QueryRowToResult(PRInt64 itemId, const nsACString& aURI,
                               const nsACString& aTitle,
                               PRUint32 aAccessCount, PRTime aTime,
                               const nsACString& aFavicon,
                               nsNavHistoryResultNode** aNode)
{
  nsCOMArray<nsNavHistoryQuery> queries;
  nsCOMPtr<nsNavHistoryQueryOptions> options;
  nsresult rv = QueryStringToQueryArray(aURI, &queries,
                                        getter_AddRefs(options));
  if (NS_FAILED(rv)) {
    // This was a query that did not parse, what do we do? We don't want to
    // return failure since that will kill the whole query process. Instead
    // make a query node with the query as a string. This way we have a valid
    // node for the user to manipulate that will look like a query, but it will
    // never populate since the query string is invalid.
    *aNode = new nsNavHistoryQueryResultNode(aURI, aTitle, aFavicon);
    if (! *aNode)
      return NS_ERROR_OUT_OF_MEMORY;
    NS_ADDREF(*aNode);
  } else {
    PRInt64 folderId = GetSimpleBookmarksQueryFolder(queries, options);
    if (folderId) {
      // simple bookmarks folder, magically generate a bookmarks folder node
      nsNavBookmarks* bookmarks = nsNavBookmarks::GetBookmarksService();
      NS_ENSURE_TRUE(bookmarks, NS_ERROR_OUT_OF_MEMORY);

      // this addrefs for us
      rv = bookmarks->ResultNodeForContainer(folderId, options, aNode);
      NS_ENSURE_SUCCESS(rv, rv);

      // this is the query item-Id, and is what is exposed by node.itemId
      (*aNode)->GetAsFolder()->mQueryItemId = itemId;

      // Use the query item title, unless it's void (in that case,
      // we keep the concrete folder title set)
      if (!aTitle.IsVoid())
        (*aNode)->mTitle = aTitle;
    } else {
      // regular query
      *aNode = new nsNavHistoryQueryResultNode(aTitle, EmptyCString(), aTime,
                                               queries, options);
      if (! *aNode)
        return NS_ERROR_OUT_OF_MEMORY;
      (*aNode)->mItemId = itemId;
      NS_ADDREF(*aNode);
    }
  }
  return NS_OK;
}


// nsNavHistory::VisitIdToResultNode
//
//    Used by the query results to create new nodes on the fly when
//    notifications come in. This just creates a node for the given visit ID.

nsresult
nsNavHistory::VisitIdToResultNode(PRInt64 visitId,
                                  nsNavHistoryQueryOptions* aOptions,
                                  nsNavHistoryResultNode** aResult)
{
  mozIStorageStatement* statement; // non-owning!

  switch (aOptions->ResultType())
  {
    case nsNavHistoryQueryOptions::RESULTS_AS_VISIT:
    case nsNavHistoryQueryOptions::RESULTS_AS_FULL_VISIT:
      // visit query - want exact visit time
      statement = mDBVisitToVisitResult;
      break;

    case nsNavHistoryQueryOptions::RESULTS_AS_URI:
      // URL results - want last visit time
      statement = mDBVisitToURLResult;
      break;

    default:
      // Query base types like RESULTS_AS_*_QUERY handle additions
      // by registering their own observers when they are expanded.
      return NS_OK;
  }

  mozStorageStatementScoper scoper(statement);
  nsresult rv = statement->BindInt64Parameter(0, visitId);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasMore = PR_FALSE;
  rv = statement->ExecuteStep(&hasMore);
  NS_ENSURE_SUCCESS(rv, rv);
  if (! hasMore) {
    NS_NOTREACHED("Trying to get a result node for an invalid visit");
    return NS_ERROR_INVALID_ARG;
  }

  return RowToResult(statement, aOptions, aResult);
}

nsresult
nsNavHistory::BookmarkIdToResultNode(PRInt64 aBookmarkId, nsNavHistoryQueryOptions* aOptions,
                                     nsNavHistoryResultNode** aResult)
{
  mozStorageStatementScoper scoper(mDBBookmarkToUrlResult);
  nsresult rv = mDBBookmarkToUrlResult->BindInt64Parameter(0, aBookmarkId);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasMore = PR_FALSE;
  rv = mDBBookmarkToUrlResult->ExecuteStep(&hasMore);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!hasMore) {
    NS_NOTREACHED("Trying to get a result node for an invalid bookmark identifier");
    return NS_ERROR_INVALID_ARG;
  }

  return RowToResult(mDBBookmarkToUrlResult, aOptions, aResult);
}

// nsNavHistory::TitleForDomain
//
//    This computes the title for a given domain. Normally, this is just the
//    domain name, but we specially handle empty cases to give you a nice
//    localized string.

void
nsNavHistory::TitleForDomain(const nsCString& domain, nsACString& aTitle)
{
  if (! domain.IsEmpty()) {
    aTitle = domain;
    return;
  }

  // use the localized one instead
  GetStringFromName(NS_LITERAL_STRING("localhost").get(), aTitle);
}

void
nsNavHistory::GetAgeInDaysString(PRInt32 aInt, const PRUnichar *aName, nsACString& aResult)
{
  nsAutoString intString;
  intString.AppendInt(aInt);
  const PRUnichar* strings[1] = { intString.get() };
  nsXPIDLString value;
  nsresult rv = mBundle->FormatStringFromName(aName, strings, 
                                              1, getter_Copies(value));
  if (NS_SUCCEEDED(rv))
    CopyUTF16toUTF8(value, aResult);
  else
    aResult.Truncate(0);
}

void
nsNavHistory::GetStringFromName(const PRUnichar *aName, nsACString& aResult)
{
  nsXPIDLString value;
  nsresult rv = mBundle->GetStringFromName(aName, getter_Copies(value));
  if (NS_SUCCEEDED(rv))
    CopyUTF16toUTF8(value, aResult);
  else
    aResult.Truncate(0);
}

// nsNavHistory::SetPageTitleInternal
//
//    Called to set the title for the given URI. Used as a
//    backend for SetTitle.
//
//    Will fail for pages that are not in the DB. To clear the corresponding
//    title, use aTitle.SetIsVoid(). Sending an empty string will save an
//    empty string instead of clearing it.

nsresult
nsNavHistory::SetPageTitleInternal(nsIURI* aURI, const nsAString& aTitle)
{
  nsresult rv;

  mozStorageTransaction transaction(mDBConn, PR_TRUE);

  // first, make sure the page exists, and fetch the old title (we need the one
  // that isn't changing to send notifications)
  nsAutoString title;
  { // scope for statement
    mozStorageStatementScoper infoScoper(mDBGetURLPageInfo);
    rv = BindStatementURI(mDBGetURLPageInfo, 0, aURI);
    NS_ENSURE_SUCCESS(rv, rv);
    PRBool hasURL = PR_FALSE;
    rv = mDBGetURLPageInfo->ExecuteStep(&hasURL);
    NS_ENSURE_SUCCESS(rv, rv);
    if (! hasURL) {
      // we don't have the URL, give up
      return NS_ERROR_NOT_AVAILABLE;
    }

    // page title
    rv = mDBGetURLPageInfo->GetString(kGetInfoIndex_Title, title);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // It is actually common to set the title to be the same thing it used to
  // be. For example, going to any web page will always cause a title to be set,
  // even though it will often be unchanged since the last visit. In these
  // cases, we can avoid DB writing and (most significantly) observer overhead.
  if ((aTitle.IsVoid() && title.IsVoid()) || aTitle == title)
    return NS_OK;

  nsCOMPtr<mozIStorageStatement> dbModStatement;
  title = aTitle;
  rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING("UPDATE moz_places SET title = ?1 WHERE url = ?2"),
      getter_AddRefs(dbModStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  // title
  if (aTitle.IsVoid())
    dbModStatement->BindNullParameter(0);
  else
    dbModStatement->BindStringParameter(0, StringHead(aTitle, HISTORY_TITLE_LENGTH_MAX));
  NS_ENSURE_SUCCESS(rv, rv);

  // url
  rv = BindStatementURI(dbModStatement, 1, aURI);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = dbModStatement->Execute();
  NS_ENSURE_SUCCESS(rv, rv);
  rv = transaction.Commit();
  NS_ENSURE_SUCCESS(rv, rv);

  // observers (have to check first if it's bookmarked)
  ENUMERATE_WEAKARRAY(mObservers, nsINavHistoryObserver,
                      OnTitleChanged(aURI, title))

  return NS_OK;

}

nsresult
nsNavHistory::AddPageWithVisit(nsIURI *aURI,
                               const nsString &aTitle,
                               PRBool aHidden,
                               PRBool aTyped,
                               PRInt32 aVisitCount,
                               PRInt32 aLastVisitTransition,
                               PRTime aLastVisitDate)
{
  PRBool canAdd = PR_FALSE;
  nsresult rv = CanAddURI(aURI, &canAdd);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!canAdd) {
    return NS_OK;
  }

  PRInt64 pageID;
  // we don't want to calculate frecency here for each uri we import
  rv = InternalAddNewPage(aURI, aTitle, aHidden, aTyped, aVisitCount, PR_FALSE, &pageID);
  NS_ENSURE_SUCCESS(rv, rv);

  if (aLastVisitDate != -1) {
    PRInt64 visitID;
    rv = InternalAddVisit(pageID, 0, 0,
                          aLastVisitDate, aLastVisitTransition, &visitID);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}

nsresult
nsNavHistory::RemoveDuplicateURIs()
{
  // this must be in a transaction because we do related queries
  mozStorageTransaction transaction(mDBConn, PR_FALSE);

  // this query chooses an id for every duplicate uris
  // this id will be retained while duplicates will be discarded
  // total_visit_count is the sum of all duplicate uris visit_count
  nsCOMPtr<mozIStorageStatement> selectStatement;
  nsresult rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING("SELECT "
        "(SELECT h.id FROM moz_places h WHERE h.url=url ORDER BY h.visit_count DESC LIMIT 1), "
        "url, SUM(visit_count) "
        "FROM moz_places "
        "GROUP BY url HAVING( COUNT(url) > 1)"),
      getter_AddRefs(selectStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  // this query remaps history visits to the retained place_id
  nsCOMPtr<mozIStorageStatement> updateStatement;
  rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING(
        "UPDATE moz_historyvisits "
        "SET place_id = ?1 "
        "WHERE place_id IN (SELECT id FROM moz_places WHERE id <> ?1 AND url = ?2)"),
      getter_AddRefs(updateStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  // this query remaps bookmarks to the retained place_id
  nsCOMPtr<mozIStorageStatement> bookmarkStatement;
  rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING(
        "UPDATE moz_bookmarks "
        "SET fk = ?1 "
        "WHERE fk IN (SELECT id FROM moz_places WHERE id <> ?1 AND url = ?2)"),
      getter_AddRefs(bookmarkStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  // this query remaps annotations to the retained place_id
  nsCOMPtr<mozIStorageStatement> annoStatement;
  rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING(
        "UPDATE moz_annos "
        "SET place_id = ?1 "
        "WHERE place_id IN (SELECT id FROM moz_places WHERE id <> ?1 AND url = ?2)"),
      getter_AddRefs(annoStatement));
  NS_ENSURE_SUCCESS(rv, rv);
  
  // this query deletes all duplicate uris except the choosen id
  nsCOMPtr<mozIStorageStatement> deleteStatement;
  rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING("DELETE FROM moz_places WHERE url = ?1 AND id <> ?2"),
      getter_AddRefs(deleteStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  // this query updates visit_count to the sum of all visits
  nsCOMPtr<mozIStorageStatement> countStatement;
  rv = mDBConn->CreateStatement(
      NS_LITERAL_CSTRING("UPDATE moz_places SET visit_count = ?1 WHERE id = ?2"),
      getter_AddRefs(countStatement));
  NS_ENSURE_SUCCESS(rv, rv);

  // for each duplicate uri we update historyvisit and visit_count
  PRBool hasMore;
  while (NS_SUCCEEDED(selectStatement->ExecuteStep(&hasMore)) && hasMore) {
    PRUint64 id = selectStatement->AsInt64(0);
    nsCAutoString url;
    rv = selectStatement->GetUTF8String(1, url);
    NS_ENSURE_SUCCESS(rv, rv);
    PRUint64 visit_count = selectStatement->AsInt64(2);

    // update historyvisits so they are remapped to the retained uri
    rv = updateStatement->BindInt64Parameter(0, id);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = updateStatement->BindUTF8StringParameter(1, url);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = updateStatement->Execute();
    NS_ENSURE_SUCCESS(rv, rv);

    // remap bookmarks to the retained id
    rv = bookmarkStatement->BindInt64Parameter(0, id);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = bookmarkStatement->BindUTF8StringParameter(1, url);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = bookmarkStatement->Execute();
    NS_ENSURE_SUCCESS(rv, rv);

    // remap annotations to the retained id
    rv = annoStatement->BindInt64Parameter(0, id);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = annoStatement->BindUTF8StringParameter(1, url);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = annoStatement->Execute();
    NS_ENSURE_SUCCESS(rv, rv);
    
    // remove duplicate uris from moz_places
    rv = deleteStatement->BindUTF8StringParameter(0, url);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = deleteStatement->BindInt64Parameter(1, id);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = deleteStatement->Execute();
    NS_ENSURE_SUCCESS(rv, rv);

    // update visit_count to the sum of all visit_count
    rv = countStatement->BindInt64Parameter(0, visit_count);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = countStatement->BindInt64Parameter(1, id);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = countStatement->Execute();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  rv = transaction.Commit();
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

// Local function **************************************************************


// GetReversedHostname
//
//    This extracts the hostname from the URI and reverses it in the
//    form that we use (always ending with a "."). So
//    "http://microsoft.com/" becomes "moc.tfosorcim."
//
//    The idea behind this is that we can create an index over the items in
//    the reversed host name column, and then query for as much or as little
//    of the host name as we feel like.
//
//    For example, the query "host >= 'gro.allizom.' AND host < 'gro.allizom/'
//    Matches all host names ending in '.mozilla.org', including
//    'developer.mozilla.org' and just 'mozilla.org' (since we define all
//    reversed host names to end in a period, even 'mozilla.org' matches).
//    The important thing is that this operation uses the index. Any substring
//    calls in a select statement (even if it's for the beginning of a string)
//    will bypass any indices and will be slow).

nsresult
GetReversedHostname(nsIURI* aURI, nsAString& aRevHost)
{
  nsCString forward8;
  nsresult rv = aURI->GetHost(forward8);
  if (NS_FAILED(rv)) {
    return rv;
  }

  // can't do reversing in UTF8, better use 16-bit chars
  nsAutoString forward = NS_ConvertUTF8toUTF16(forward8);
  GetReversedHostname(forward, aRevHost);
  return NS_OK;
}


// GetReversedHostname
//
//    Same as previous but for strings

void
GetReversedHostname(const nsString& aForward, nsAString& aRevHost)
{
  ReverseString(aForward, aRevHost);
  aRevHost.Append(PRUnichar('.'));
}


// GetSimpleBookmarksQueryFolder
//
//    Determines if this set of queries is a simple bookmarks query for a
//    folder with no other constraints. In these common cases, we can more
//    efficiently compute the results.
//
//    A simple bookmarks query will result in a hierarchical tree of
//    bookmark items, folders and separators.
//
//    Returns the folder ID if it is a simple folder query, 0 if not.
static PRInt64
GetSimpleBookmarksQueryFolder(const nsCOMArray<nsNavHistoryQuery>& aQueries,
                              nsNavHistoryQueryOptions* aOptions)
{
  if (aQueries.Count() != 1)
    return 0;

  nsNavHistoryQuery* query = aQueries[0];
  if (query->Folders().Length() != 1)
    return 0;

  PRBool hasIt;
  query->GetHasBeginTime(&hasIt);
  if (hasIt)
    return 0;
  query->GetHasEndTime(&hasIt);
  if (hasIt)
    return 0;
  query->GetHasDomain(&hasIt);
  if (hasIt)
    return 0;
  query->GetHasUri(&hasIt);
  if (hasIt)
    return 0;
  (void)query->GetHasSearchTerms(&hasIt);
  if (hasIt)
    return 0;
  if (aOptions->MaxResults() > 0)
    return 0;

  // RESULTS_AS_TAG_CONTENTS is quite similar to a folder shortcut, but we must
  // avoid treating it like that, since we need to retain all query options.
  if(aOptions->ResultType() == nsINavHistoryQueryOptions::RESULTS_AS_TAG_CONTENTS)
    return 0;

  // Note that we don't care about the onlyBookmarked flag, if you specify a bookmark
  // folder, onlyBookmarked is inferred.
  NS_ASSERTION(query->Folders()[0] > 0, "bad folder id");
  return query->Folders()[0];
}


// ParseSearchTermsFromQueries
//
//    Construct a matrix of search terms from the given queries array.
//    All of the query objects are ORed together. Within a query, all the terms
//    are ANDed together. See nsINavHistoryService.idl.
//
//    This just breaks the query up into words. We don't do anything fancy,
//    not even quoting. We do, however, strip quotes, because people might
//    try to input quotes expecting them to do something and get no results
//    back.

inline PRBool isQueryWhitespace(PRUnichar ch)
{
  return ch == ' ';
}

void ParseSearchTermsFromQueries(const nsCOMArray<nsNavHistoryQuery>& aQueries,
                                 nsTArray<nsStringArray*>* aTerms)
{
  PRInt32 lastBegin = -1;
  for (PRUint32 i=0; i < aQueries.Count(); i++) {
    nsStringArray *queryTerms = new nsStringArray();
    PRBool hasSearchTerms;
    if (NS_SUCCEEDED(aQueries[i]->GetHasSearchTerms(&hasSearchTerms)) &&
        hasSearchTerms) {
      const nsString& searchTerms = aQueries[i]->SearchTerms();
      for (PRUint32 j = 0; j < searchTerms.Length(); j++) {
        if (isQueryWhitespace(searchTerms[j]) ||
            searchTerms[j] == '"') {
          if (lastBegin >= 0) {
            // found the end of a word
            queryTerms->AppendString(Substring(searchTerms, lastBegin,
                                               j - lastBegin));
            lastBegin = -1;
          }
        } else {
          if (lastBegin < 0) {
            // found the beginning of a word
            lastBegin = j;
          }
        }
      }
      // last word
      if (lastBegin >= 0)
        queryTerms->AppendString(Substring(searchTerms, lastBegin));
    }
    aTerms->AppendElement(queryTerms);
  }
}


// GenerateTitleFromURI
//
//    Given a URL, we try to get a reasonable title for this page. We try
//    to use a filename out of the URI, then fall back on the path, then fall
//    back on the whole hostname.

nsresult // static
GenerateTitleFromURI(nsIURI* aURI, nsAString& aTitle)
{
  nsCAutoString name;
  nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
  if (url)
    url->GetFileName(name);
  if (name.IsEmpty()) {
    // path
    nsresult rv = aURI->GetPath(name);
    if (NS_FAILED(rv) || (name.Length() == 1 && name[0] == '/')) {
      // empty path name, use hostname
      rv = aURI->GetHost(name);
      NS_ENSURE_SUCCESS(rv, rv);
    }
  }
  aTitle = NS_ConvertUTF8toUTF16(name);
  return NS_OK;
}


// BindStatementURI
//
//    Binds the specified URI as the parameter 'index' for the statment.
//    URIs are always bound as UTF8

nsresult BindStatementURI(mozIStorageStatement* statement, PRInt32 index,
                          nsIURI* aURI)
{
  NS_ENSURE_ARG_POINTER(aURI);

  nsCAutoString utf8URISpec;
  nsresult rv = aURI->GetSpec(utf8URISpec);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = statement->BindUTF8StringParameter(index,
      StringHead(utf8URISpec, HISTORY_URI_LENGTH_MAX));
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

nsresult
nsNavHistory::UpdateFrecency(PRInt64 aPlaceId, PRBool aIsBookmarked)
{
  mozStorageStatementScoper statsScoper(mDBGetPlaceVisitStats);
  nsresult rv = mDBGetPlaceVisitStats->BindInt64Parameter(0, aPlaceId);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasResults = PR_FALSE;
  rv = mDBGetPlaceVisitStats->ExecuteStep(&hasResults);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!hasResults) {
    NS_WARNING("attempting to update frecency for a bogus place");
    // before I added the check for itemType == TYPE_BOOKMARK
    // I hit this with aPlaceId of 0 (on import)
    return NS_OK;
  }

  PRInt32 typed = 0;
  rv = mDBGetPlaceVisitStats->GetInt32(0, &typed);
  NS_ENSURE_SUCCESS(rv, rv);

  PRInt32 hidden = 0;
  rv = mDBGetPlaceVisitStats->GetInt32(1, &hidden);
  NS_ENSURE_SUCCESS(rv, rv);

  PRInt32 oldFrecency = 0;
  rv = mDBGetPlaceVisitStats->GetInt32(2, &oldFrecency);
  NS_ENSURE_SUCCESS(rv, rv);

  PRInt32 visitCountForFrecency = 0;

  // because visit_count excludes visit with visit_type NOT IN(0,4,7)
  // we can't use it for calculating frecency, so we must
  // calculate it.
  rv = CalculateFullVisitCount(aPlaceId, &visitCountForFrecency);
  NS_ENSURE_SUCCESS(rv, rv);

  PRInt32 newFrecency = 0;
  rv = CalculateFrecencyInternal(aPlaceId, typed, visitCountForFrecency,
                                 aIsBookmarked, &newFrecency);
  NS_ENSURE_SUCCESS(rv, rv);

  // save ourselves the UPDATE if the frecency hasn't changed
  // One way this can happen is with livemarks.
  // when we added the livemark, the frecency was 0.  
  // On refresh, when we remove and then add the livemark items,
  // the frecency (for a given moz_places) will not have changed
  // (if we've never visited that place).
  // Additionally, don't bother overwriting a valid frecency with an invalid one
  if (newFrecency == oldFrecency || oldFrecency && newFrecency < 0)
    return NS_OK;

  mozStorageStatementScoper updateScoper(mDBUpdateFrecencyAndHidden);
  rv = mDBUpdateFrecencyAndHidden->BindInt64Parameter(0, aPlaceId);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mDBUpdateFrecencyAndHidden->BindInt32Parameter(1, newFrecency);
  NS_ENSURE_SUCCESS(rv, rv);

  // if we calculated a non-zero frecency we should unhide this place
  // so that previously hidden (non-livebookmark item) bookmarks 
  // will now appear in autocomplete
  // if we calculated a zero frecency, we re-use the old hidden value.
  rv = mDBUpdateFrecencyAndHidden->BindInt32Parameter(2, 
         newFrecency ? 0 /* not hidden */ : hidden);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mDBUpdateFrecencyAndHidden->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
nsNavHistory::CalculateFrecencyInternal(PRInt64 aPlaceId,
                                        PRInt32 aTyped,
                                        PRInt32 aVisitCount,
                                        PRBool aIsBookmarked,
                                        PRInt32 *aFrecency)
{
  PRTime normalizedNow = NormalizeTimeRelativeToday(GetNow());

  float pointsForSampledVisits = 0.0;

  if (aPlaceId != -1) {
    PRInt32 numSampledVisits = 0;

    mozStorageStatementScoper scoper(mDBVisitsForFrecency);
    nsresult rv = mDBVisitsForFrecency->BindInt64Parameter(0, aPlaceId);
    NS_ENSURE_SUCCESS(rv, rv);

    // mDBVisitsForFrecency is limited by the browser.frecency.numVisits pref
    PRBool hasMore = PR_FALSE;
    while (NS_SUCCEEDED(mDBVisitsForFrecency->ExecuteStep(&hasMore)) 
           && hasMore) {
      numSampledVisits++;

      PRInt32 visitType = mDBVisitsForFrecency->AsInt32(1);

      PRInt32 bonus = 0;

      switch (visitType) {
        case nsINavHistoryService::TRANSITION_EMBED:
          bonus = mEmbedVisitBonus;
          break;
        case nsINavHistoryService::TRANSITION_LINK:
          bonus = mLinkVisitBonus;
          break;
        case nsINavHistoryService::TRANSITION_TYPED:
          bonus = mTypedVisitBonus;
          break;
        case nsINavHistoryService::TRANSITION_BOOKMARK:
          bonus = mBookmarkVisitBonus;
          break;
        case nsINavHistoryService::TRANSITION_DOWNLOAD:
          bonus = mDownloadVisitBonus;
          break;
        case nsINavHistoryService::TRANSITION_REDIRECT_PERMANENT:
          bonus = mPermRedirectVisitBonus;
          break;
        case nsINavHistoryService::TRANSITION_REDIRECT_TEMPORARY:
          bonus = mTempRedirectVisitBonus;
          break;
        default:
          // 0 == undefined (see bug #375777 for details)
          if (visitType)
            NS_WARNING("new transition but no weight for frecency");
          bonus = mDefaultVisitBonus;
          break;
      }

      // if bonus was zero, we can skip the work to determine the weight
      if (bonus) {
        PRTime visitDate = mDBVisitsForFrecency->AsInt64(0);
        PRInt64 ageInDays = GetAgeInDays(normalizedNow, visitDate);

        PRInt32 weight = 0;

        if (ageInDays <= mFirstBucketCutoffInDays)
          weight = mFirstBucketWeight;
        else if (ageInDays <= mSecondBucketCutoffInDays)
          weight = mSecondBucketWeight;
        else if (ageInDays <= mThirdBucketCutoffInDays)
          weight = mThirdBucketWeight;
        else if (ageInDays <= mFourthBucketCutoffInDays) 
          weight = mFourthBucketWeight;
        else
          weight = mDefaultWeight;

        pointsForSampledVisits += weight * (bonus / 100.0);
      }
    }

    if (numSampledVisits) {
      // fix for bug #412219
      if (!pointsForSampledVisits) {
        // For URIs with zero points in the sampled recent visits
        // but "browsing" type visits outside the sampling range, set
        // frecency to -visit_count, so they're still shown in autocomplete.
        PRInt32 visitCount = 0;
        mozStorageStatementScoper scoper(mDBGetIdPageInfo);
        rv = mDBGetIdPageInfo->BindInt64Parameter(0, aPlaceId);
        NS_ENSURE_SUCCESS(rv, rv);

        PRBool hasVisits = PR_TRUE;
        if (NS_SUCCEEDED(mDBGetIdPageInfo->ExecuteStep(&hasVisits)) && hasVisits) {
          rv = mDBGetIdPageInfo->GetInt32(nsNavHistory::kGetInfoIndex_VisitCount,
                                          &visitCount);
          NS_ENSURE_SUCCESS(rv, rv);
        }
        // If we don't have visits set to 0
        *aFrecency = -visitCount;
      }
      else {
        // Estimate frecency using the last few visits.
        // Use NS_ceilf() so that we don't round down to 0, which
        // would cause us to completely ignore the place during autocomplete.
        *aFrecency = (PRInt32) NS_ceilf(aVisitCount * NS_ceilf(pointsForSampledVisits) / numSampledVisits);
      }

#ifdef DEBUG_FRECENCY
      printf("CalculateFrecency() for place %lld: %d = %d * %f / %d\n", aPlaceId, *aFrecency, aVisitCount, pointsForSampledVisits, numSampledVisits);
#endif

      return NS_OK;
    }
  }
 
  // XXX the code below works well for guessing the frecency on import, and we'll correct later once we have
  // visits.
  // what if we don't have visits and we never visit?  we could end up with a really high value
  // that keeps coming up in ac results?  only do this on import?  something to figure out.
  PRInt32 bonus = 0;

  // not the same logic above, as a single visit could not be both
  // a bookmark visit and a typed visit.  but when estimating a frecency
  // for a place that doesn't have any visits, this will make it so
  // something bookmarked and typed will have a higher frecency than
  // something just typed or just bookmarked.
  if (aIsBookmarked)
    bonus += mUnvisitedBookmarkBonus;
  if (aTyped)
    bonus += mUnvisitedTypedBonus;

  // assume "now" as our ageInDays, so use the first bucket.
  // note, when we recalculate "old frecencies" (see mDBOldFrecencies)
  // this frecency value could be off by an order of 
  // (mFirstBucketWeight / mDefaultBucketWeight)
  pointsForSampledVisits = mFirstBucketWeight * (bonus / (float)100.0); 
   
  // for a unvisited bookmark, produce a non-zero frecency
  // so that unvisited bookmarks show up in URL bar autocomplete
  if (!aVisitCount && aIsBookmarked)
    aVisitCount = 1;

  // use NS_ceilf() so that we don't round down to 0, which
  // would cause us to completely ignore the place during autocomplete
  *aFrecency = (PRInt32) NS_ceilf(aVisitCount * NS_ceilf(pointsForSampledVisits));
#ifdef DEBUG_FRECENCY
  printf("CalculateFrecency() for unvisited: frecency %d = %f points (b: %d, t: %d) * visit count %d\n", *aFrecency, pointsForSampledVisits, aIsBookmarked, aTyped, aVisitCount);
#endif
  return NS_OK;
}

nsresult 
nsNavHistory::CalculateFrecency(PRInt64 aPlaceId,
                                PRInt32 aTyped,
                                PRInt32 aVisitCount,
                                nsCAutoString &aURL,
                                PRInt32 *aFrecency)
{
  *aFrecency = 0;

  nsresult rv;

  nsCOMPtr<nsILivemarkService> lms = 
    do_GetService(NS_LIVEMARKSERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool isBookmark = PR_FALSE;

  // determine if the place is a (non-livemark item) bookmark and prevent
  // place: queries from showing up in the URL bar autocomplete results
  if (!IsQueryURI(aURL) && aPlaceId != -1) {
    mozStorageStatementScoper scope(mDBGetBookmarkParentsForPlace);

    rv = mDBGetBookmarkParentsForPlace->BindInt64Parameter(0, aPlaceId);
    NS_ENSURE_SUCCESS(rv, rv);
   
    // this query can return multiple parent folders because
    // it is possible for the user to bookmark something that
    // is also a livemark item
    PRBool hasMore = PR_FALSE;
    while (NS_SUCCEEDED(mDBGetBookmarkParentsForPlace->ExecuteStep(&hasMore)) 
           && hasMore) {
      PRInt64 folderId;
      rv = mDBGetBookmarkParentsForPlace->GetInt64(0, &folderId);
      NS_ENSURE_SUCCESS(rv, rv);

      PRBool parentIsLivemark;
      rv = lms->IsLivemark(folderId, &parentIsLivemark);
      NS_ENSURE_SUCCESS(rv, rv);

      // we found one parent that is not a livemark feed, so we can stop
      if (!parentIsLivemark) {
        isBookmark = PR_TRUE;
        break;
      }
    }
  }

  rv = CalculateFrecencyInternal(aPlaceId, aTyped, aVisitCount,
                                 isBookmark, aFrecency);
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

nsresult
nsNavHistory::RecalculateFrecencies(PRInt32 aCount, PRBool aRecalcOld)
{
  mozStorageTransaction transaction(mDBConn, PR_TRUE);

  nsresult rv = RecalculateFrecenciesInternal(mDBInvalidFrecencies, aCount);
  NS_ENSURE_SUCCESS(rv, rv);

  if (aRecalcOld) {
    rv = RecalculateFrecenciesInternal(mDBOldFrecencies, aCount);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  return NS_OK;
}

nsresult 
nsNavHistory::RecalculateFrecenciesInternal(mozIStorageStatement *aStatement, PRInt32 aCount)
{
  mozStorageStatementScoper scoper(aStatement);

  nsresult rv = aStatement->BindInt32Parameter(0, aCount);
  NS_ENSURE_SUCCESS(rv, rv);

  PRBool hasMore = PR_FALSE;
  while (NS_SUCCEEDED(aStatement->ExecuteStep(&hasMore)) && hasMore) {
    PRInt64 placeId = aStatement->AsInt64(0);
    // for frecency, we don't use visit_count, aStatement->AsInt32(1)
    PRInt32 hidden = aStatement->AsInt32(2);
    PRInt32 typed = aStatement->AsInt32(3);
    PRInt32 oldFrecency = aStatement->AsInt32(4);

    nsCAutoString url;
    aStatement->GetUTF8String(5, url);

    PRInt32 newFrecency = 0;
    PRInt32 visitCountForFrecency = 0;

    // because visit_count excludes visit with visit_type NOT IN(0,4,7)
    // we can't use it for calculating frecency so we must calculate it.
    rv = CalculateFullVisitCount(placeId, &visitCountForFrecency);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = CalculateFrecency(placeId, typed, visitCountForFrecency, 
                           url, &newFrecency);
    NS_ENSURE_SUCCESS(rv, rv);

    // save ourselves the UPDATE if the frecency hasn't changed
    if (newFrecency == oldFrecency)
      continue;

    mozStorageStatementScoper updateScoper(mDBUpdateFrecencyAndHidden);
    rv = mDBUpdateFrecencyAndHidden->BindInt64Parameter(0, placeId);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBUpdateFrecencyAndHidden->BindInt32Parameter(1, newFrecency);
    NS_ENSURE_SUCCESS(rv, rv);

    // if we calculated a non-zero frecency we should unhide this place
    // so that previously hidden (non-livebookmark items) bookmarks 
    // will now appear in autocomplete.  if we calculated a zero frecency, 
    // we re-use the old hidden value.
    rv = mDBUpdateFrecencyAndHidden->BindInt32Parameter(2, 
           newFrecency ? 0 /* not hidden */ : hidden);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mDBUpdateFrecencyAndHidden->Execute();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}

// nsICharsetResolver **********************************************************

NS_IMETHODIMP
nsNavHistory::RequestCharset(nsIWebNavigation* aWebNavigation,
                             nsIChannel* aChannel,
                             PRBool* aWantCharset,
                             nsISupports** aClosure,
                             nsACString& aResult)
{
  *aWantCharset = PR_FALSE;
  *aClosure = nsnull;

  nsCOMPtr<nsIURI> uri;
  nsresult rv = aChannel->GetURI(getter_AddRefs(uri));
  if (NS_FAILED(rv))
    return NS_OK;

  nsAutoString charset;
  rv = GetCharsetForURI(uri, charset);
  NS_ENSURE_SUCCESS(rv, rv);

  CopyUTF16toUTF8(charset, aResult);
  return NS_OK;
}

NS_IMETHODIMP
nsNavHistory::NotifyResolvedCharset(const nsACString& aCharset,
                                    nsISupports* aClosure)
{
    NS_ERROR("Unexpected call to NotifyResolvedCharset -- we never set aWantCharset to true!");
    return NS_ERROR_NOT_IMPLEMENTED;
}