Пример #1
0
 private void UpdateSearchCompletionPercentage(
     Progress.IProgressEventsSink progress,
     long lastHandledPosition,
     FileRange.Range fullSearchPositionsRange,
     bool skipMessagesCountCheck)
 {
     if (progress == null)
     {
         return;
     }
     if (!skipMessagesCountCheck && (messagesReadSinceCompletionPercentageUpdate % 256) != 0)
     {
         ++messagesReadSinceCompletionPercentageUpdate;
     }
     else
     {
         double value;
         if (fullSearchPositionsRange.Length > 0)
         {
             value = Math.Max(0d, (double)(lastHandledPosition - fullSearchPositionsRange.Begin) / (double)fullSearchPositionsRange.Length);
         }
         else
         {
             value = 0;
         }
         progress.SetValue(value);
         messagesReadSinceCompletionPercentageUpdate = 0;
     }
 }
Пример #2
0
 public ParserImpl(LogEntry[] logContent, CreateParserParams parserParams)
 {
     this.logContent = logContent;
     if (parserParams.Range.HasValue)
     {
         effectiveRange = parserParams.Range.Value;
         if (effectiveRange.Begin < 0)
         {
             effectiveRange = new Range(0, effectiveRange.End);
         }
         if (effectiveRange.End > logContent.Length)
         {
             effectiveRange = new Range(effectiveRange.Begin, logContent.Length);
         }
     }
     else
     {
         effectiveRange = new Range(0, logContent.Length);
     }
     reverse = parserParams.Direction == MessagesParserDirection.Backward;
     if (!reverse)
     {
         pos = Math.Max(parserParams.StartPosition, effectiveRange.Begin);
     }
     else
     {
         pos = Math.Min(parserParams.StartPosition - 1, effectiveRange.End);
     }
 }
        public long PositionRangeToBytes(FileRange.Range range)
        {
            // Here calculation is not precise: TextStreamPosition cannot be converted to bytes
            // directly and efficiently. But this function is used only for statistics so it's ok to
            // use approximate calculations here.
            var encoding = StreamEncoding;

            return(TextStreamPositionToStreamPosition_Approx(range.End, encoding, textStreamPositioningParams) - TextStreamPositionToStreamPosition_Approx(range.Begin, encoding, textStreamPositioningParams));
        }
Пример #4
0
 public EnumMessagesHelper(
     ILogSource ls,
     CancellationToken cancellation,
     Progress.IProgressEventsSink progress
     )
 {
     this.ls              = ls;
     this.cancellation    = cancellation;
     this.progress        = progress;
     this.lsRange         = ls.Provider.Stats.PositionsRange;
     this.lastReadPositon = lsRange.Begin;
 }
Пример #5
0
 static IEnumerableAsync <FileRange.Range> IterateMatchRanges(
     IEnumerableAsync <Checkpoint> checkpoints, long threshhold, ProgressAndCancellation progressAndCancellation)
 {
     return(EnumerableAsync.Produce <FileRange.Range>(async yieldAsync =>
     {
         FileRange.Range?lastMatch = null;
         await checkpoints.ForEach(async checkpoint =>
         {
             if (lastMatch == null)
             {
                 if (checkpoint.IsMatch)
                 {
                     lastMatch = new FileRange.Range(checkpoint.Position, checkpoint.EndPosition);
                 }
                 else
                 {
                     progressAndCancellation.continuationToken.NextPosition = checkpoint.EndPosition;
                     progressAndCancellation.HandleTextIterationProgress(checkpoint.EndPosition);
                 }
             }
             else
             {
                 FileRange.Range lastMatchVal = lastMatch.Value;
                 if (checkpoint.Position - lastMatchVal.End < threshhold)
                 {
                     if (checkpoint.IsMatch)
                     {
                         lastMatch = new FileRange.Range(lastMatchVal.Begin, checkpoint.EndPosition);
                     }
                 }
                 else
                 {
                     await yieldAsync.YieldAsync(lastMatchVal);
                     progressAndCancellation.continuationToken.NextPosition = checkpoint.EndPosition;
                     progressAndCancellation.HandleTextIterationProgress(checkpoint.EndPosition);
                     if (checkpoint.IsMatch)
                     {
                         lastMatch = new FileRange.Range(checkpoint.Position, checkpoint.EndPosition);
                     }
                     else
                     {
                         lastMatch = null;
                     }
                 }
             }
             return true;
         });
         if (lastMatch != null)
         {
             await yieldAsync.YieldAsync(lastMatch.Value);
         }
     }));
 }
Пример #6
0
        static IEnumerable <FileRange.Range> IterateMatchRanges(
            IEnumerable <Checkpoint> checkpoints, long threshhold, ProgressAndCancellation progressAndCancellation)
        {
            FileRange.Range?lastMatch = null;
            foreach (var checkpoint in checkpoints)
            {
                if (lastMatch == null)
                {
                    if (checkpoint.IsMatch)
                    {
                        lastMatch = new FileRange.Range(checkpoint.Position, checkpoint.EndPosition);
                    }
                    else
                    {
                        progressAndCancellation.continuationToken.NextPosition = checkpoint.EndPosition;
                        progressAndCancellation.HandleTextIterationProgress(checkpoint.EndPosition);
                    }
                }
                else
                {
                    FileRange.Range lastMatchVal = lastMatch.Value;
                    if (checkpoint.Position - lastMatchVal.End < threshhold)
                    {
                        if (checkpoint.IsMatch)
                        {
                            lastMatch = new FileRange.Range(lastMatchVal.Begin, checkpoint.EndPosition);
                        }
                    }
                    else
                    {
                        yield return(lastMatchVal);

                        progressAndCancellation.continuationToken.NextPosition = checkpoint.EndPosition;
                        progressAndCancellation.HandleTextIterationProgress(checkpoint.EndPosition);
                        if (checkpoint.IsMatch)
                        {
                            lastMatch = new FileRange.Range(checkpoint.Position, checkpoint.EndPosition);
                        }
                        else
                        {
                            lastMatch = null;
                        }
                    }
                }
            }
            if (lastMatch != null)
            {
                yield return(lastMatch.Value);
            }
        }
Пример #7
0
        static bool DetectOutOfRangeCondition(FileRange.Range range, long startPosition, MessagesParserDirection direction)
        {
            bool posIsOutOfRange = !range.IsInRange(startPosition);

            if (posIsOutOfRange &&
                direction == MessagesParserDirection.Backward &&
                startPosition == range.End)
            {
                // it's ok to start reading from end position when we move backward
                posIsOutOfRange = false;
            }

            return(posIsOutOfRange);
        }
Пример #8
0
        async Task IAsyncLogProviderCommandHandler.ContinueAsynchronously(CommandContext ctx)
        {
            using (var innerCancellation = CancellationTokenSource.CreateLinkedTokenSource(ctx.Cancellation, ctx.Preemption))
            {
                var searchRange = new FileRange.Range(
                    searchParams.FromPosition.GetValueOrDefault(ctx.Reader.BeginPosition), ctx.Reader.EndPosition);

                var parserParams = new CreateSearchingParserParams()
                {
                    Range             = searchRange,
                    SearchParams      = searchParams,
                    Cancellation      = innerCancellation.Token,
                    ContinuationToken = continuationToken,
                    ProgressHandler   = pos => UpdateSearchCompletionPercentage(progress, pos, searchRange, false)
                };

                try
                {
                    var parser = ctx.Reader.CreateSearchingParser(parserParams);
                    try
                    {
                        for (; ;)
                        {
                            var msg = await parser.GetNext();

                            if (msg.Message == null || !callback(msg))
                            {
                                break;
                            }
                        }
                    }
                    finally
                    {
                        await parser.Dispose();
                    }
                }
                catch (SearchCancelledException e)                 // todo: impl it for xml reader
                {
                    if (ctx.Preemption.IsCancellationRequested)
                    {
                        continuationToken = e.ContinuationToken;
                    }
                    throw;
                }
            }
        }
Пример #9
0
        public SearchingParser(
            IPositionedMessagesReader owner,
            CreateSearchingParserParams p,
            TextStreamPositioningParams textStreamPositioningParams,
            DejitteringParams?dejitteringParams,
            Stream rawStream,
            Encoding streamEncoding,
            bool allowPlainTextSearchOptimization,
            LoadedRegex headerRe,
            ILogSourceThreads threads,
            ITraceSourceFactory traceSourceFactory,
            RegularExpressions.IRegexFactory regexFactory
            )
        {
            this.owner        = owner;
            this.parserParams = p;
            this.plainTextSearchOptimizationAllowed = allowPlainTextSearchOptimization && ((p.Flags & MessagesParserFlag.DisablePlainTextSearchOptimization) == 0);
            this.threads        = threads;
            this.requestedRange = p.Range;
            this.textStreamPositioningParams = textStreamPositioningParams;
            this.dejitteringParams           = dejitteringParams;
            this.rawStream      = rawStream;
            this.streamEncoding = streamEncoding;
            this.regexFactory   = regexFactory;
            this.trace          = traceSourceFactory.CreateTraceSource("LogSource", "srchp." + GetHashCode().ToString("x"));
            this.dummyFilter    = new Filter(FilterAction.Include, "", true, new Search.Options(), null, regexFactory);
            var continuationToken = p.ContinuationToken as ContinuationToken;

            if (continuationToken != null)
            {
                this.requestedRange = new FileRange.Range(continuationToken.NextPosition, requestedRange.End);
            }
            this.aligmentTextAccess      = new StreamTextAccess(rawStream, streamEncoding, textStreamPositioningParams);
            this.aligmentSplitter        = new MessagesSplitter(aligmentTextAccess, headerRe.Clone().Regex, headerRe.GetHeaderReSplitterFlags());
            this.aligmentCapture         = new TextMessageCapture();
            this.progressAndCancellation = new ProgressAndCancellation()
            {
                progressHandler   = p.ProgressHandler,
                cancellationToken = p.Cancellation,
                continuationToken = new ContinuationToken()
                {
                    NextPosition = requestedRange.Begin
                }
            };
            this.impl = Enum();
        }
Пример #10
0
        public void BeginSplittingSession(FileRange.Range range, long startPosition, MessagesParserDirection direction)
        {
            if (sessionIsOpen)
            {
                throw new InvalidOperationException("Cannot start more than one reading session for a single splitter");
            }

            try
            {
                TryBeginSplittingSession(range, startPosition, direction);
            }
            catch
            {
                ReadingSessionCleanup();
                throw;
            }

            sessionIsOpen = true;
        }
Пример #11
0
        void TryBeginSplittingSession(FileRange.Range range, long startPosition, MessagesParserDirection direction)
        {
            bool posIsOutOfRange = DetectOutOfRangeCondition(range, startPosition, direction);

            if (!posIsOutOfRange)
            {
                TextAccessDirection accessDirection = direction == MessagesParserDirection.Forward ?
                                                      TextAccessDirection.Forward : TextAccessDirection.Backward;

                textIterator = textAccess.OpenIterator(startPosition, accessDirection);

                try
                {
                    headerPointer1     = textIterator.PositionToCharIndex(startPosition);
                    prevHeaderPointer1 = headerPointer1;
                }
                catch (ArgumentOutOfRangeException)
                {
                    posIsOutOfRange = true;
                }
            }

            headersCounter = 0;

            if (posIsOutOfRange)
            {
                this.range = new FileRange.Range();
                SetCachedCurrentBuffer("");
                currentMessageHeaderMatch = null;
                ReadingSessionCleanup();
            }
            else
            {
                this.range = range;
                SetCurrentDirection(direction);
                UpdateCachedCurrentBuffer();
                FindNextMessageStart();
            }
        }
        static long CalcMaxActiveRangeSize(Settings.IGlobalSettingsAccessor settings, FileRange.Range availableRange)
        {
            long MB                 = 1024 * 1024;
            long sizeThreshold      = settings.FileSizes.Threshold * MB;
            long partialLoadingSize = settings.FileSizes.WindowSize * MB;

            long currentSize = availableRange.End - availableRange.Begin;

            if (currentSize < sizeThreshold)
            {
                return(currentSize);
            }
            else
            {
                return(partialLoadingSize);
            }
        }
Пример #13
0
        bool UpdateAvailableTime(bool incrementalMode)
        {
            bool itIsFirstUpdate = firstUpdateFlag;

            firstUpdateFlag = false;

            UpdateBoundsStatus status = reader.UpdateAvailableBounds(incrementalMode);

            if (status == UpdateBoundsStatus.NothingUpdated && incrementalMode)
            {
                return(false);
            }

            if (status == UpdateBoundsStatus.OldMessagesAreInvalid)
            {
                incrementalMode = false;
            }

            // Get new boundary values into temporary variables
            IMessage newFirst, newLast;

            PositionedMessagesUtils.GetBoundaryMessages(reader, null, out newFirst, out newLast);

            if (firstMessage != null)
            {
                if (newFirst == null || MessageTimestamp.Compare(newFirst.Time, firstMessage.Time) != 0)
                {
                    // The first message we've just read differs from the cached one.
                    // This means that the log was overwritten. Fall to non-incremental mode.
                    incrementalMode = false;
                }
            }

            if (!incrementalMode)
            {
                if (!itIsFirstUpdate)
                {
                    // Reset everything that has been loaded so far
                    InvalidateEverythingThatHasBeenLoaded();
                }
                firstMessage = null;
            }

            // Try to get the dates range for new bounday messages
            DateRange newAvailTime = GetAvailableDateRangeHelper(newFirst, newLast);

            firstMessage = newFirst;

            // Getting here means that the boundaries changed.
            // Fire the notfication.

            var positionsRange = new FileRange.Range(reader.BeginPosition, reader.EndPosition);

            if (!incrementalMode)
            {
                readerContentsEtag = reader.GetContentsEtag();
            }

            int contentsEtag =
                readerContentsEtag
                ^ positionsRange.Begin.GetHashCode()
                ^ positionsRange.End.GetHashCode();

            StatsTransaction(stats =>
            {
                stats.AvailableTime    = newAvailTime;
                LogProviderStatsFlag f = LogProviderStatsFlag.AvailableTime;
                if (incrementalMode)
                {
                    f |= LogProviderStatsFlag.AvailableTimeUpdatedIncrementallyFlag;
                }
                stats.TotalBytes = reader.SizeInBytes;
                f |= LogProviderStatsFlag.BytesCount;
                stats.PositionsRange = positionsRange;
                f |= LogProviderStatsFlag.PositionsRange;
                stats.PositionsRangeUpdatesCount++;
                if (stats.ContentsEtag == null || contentsEtag != stats.ContentsEtag.Value)
                {
                    stats.ContentsEtag = contentsEtag;
                    f |= LogProviderStatsFlag.ContentsEtag;
                }
                return(f);
            });

            return(true);
        }
Пример #14
0
            public static MessageFilteringResult GetFilteringResultFromPostprocessorResult(object obj)
            {
                var f = (IFilter)obj;

                if (f == null)
                {
                    return new MessageFilteringResult {
                               Action = FilterAction.Exclude
                    }
                }
                ;
                if (f == dummyFilter)
                {
                    return new MessageFilteringResult {
                               Action = FilterAction.Include
                    }
                }
                ;
                return(new MessageFilteringResult
                {
                    Action = f.Action,
                    Filter = f
                });
            }
        };

        IEnumerable <SearchResultMessage> Enum()
        {
            using (var threadsBulkProcessing = threads.UnderlyingThreadsContainer.StartBulkProcessing())
            {
                Func <IMessagesPostprocessor> postprocessor =
                    () => new MessagesPostprocessor(parserParams.SearchParams, trace);
                long searchableRangesLength = 0;
                int  searchableRangesCount  = 0;
                long totalMessagesCount     = 0;
                long totalHitsCount         = 0;
                foreach (var currentSearchableRange in EnumSearchableRanges())
                {
                    searchableRangesLength += currentSearchableRange.Length;

                    ++searchableRangesCount;
                    using (var parser = CreateParserForSearchableRange(currentSearchableRange, postprocessor))
                    {
                        long messagesCount = 0;
                        long hitsCount     = 0;
                        for (;;)
                        {
                            var tmp = parser.ReadNextAndPostprocess();
                            if (tmp.Message == null)
                            {
                                break;
                            }

                            ++messagesCount;

                            var msg             = tmp.Message;
                            var filteringResult = MessagesPostprocessor.GetFilteringResultFromPostprocessorResult(
                                tmp.PostprocessingResult);

                            if (filteringResult.Action != FilterAction.Exclude)
                            {
                                ++hitsCount;
                                yield return(new SearchResultMessage(msg, filteringResult));
                            }

                            progressAndCancellation.HandleMessageReadingProgress(msg.Position);
                            progressAndCancellation.continuationToken.NextPosition = msg.EndPosition;

                            progressAndCancellation.CheckTextIterationCancellation();
                        }
                        PrintPctStats(string.Format("hits pct in range {0}", currentSearchableRange),
                                      hitsCount, messagesCount);
                        totalMessagesCount += messagesCount;
                        totalHitsCount     += hitsCount;
                    }
                }
                trace.Info("Stats: searchable ranges count: {0}", searchableRangesCount);
                trace.Info("Stats: ave searchable range len: {0}",
                           searchableRangesCount != 0 ? searchableRangesLength / searchableRangesCount : 0);
                PrintPctStats("searchable ranges coverage pct", searchableRangesLength, requestedRange.Length);
                PrintPctStats("hits pct overall", totalHitsCount, totalMessagesCount);
            }

            yield return(new SearchResultMessage(null, new MessageFilteringResult()));
        }

        void PrintPctStats(string name, long num, long denum)
        {
            trace.Info("Stats: {0}: {1:F4}%", name, denum != 0 ? num * 100d / denum : 0d);
        }

        IEnumerable <FileRange.Range> EnumSearchableRanges()
        {
            var matcher = new PlainTextMatcher(parserParams, textStreamPositioningParams, plainTextSearchOptimizationAllowed);

            if (!matcher.PlainTextSearchOptimizationPossible)
            {
                yield return(requestedRange);

                yield break;
            }
            long?skipRangesDownThisPosition = null;

            foreach (var currentRange in EnumSearchableRangesCore(matcher))
            {
                if (skipRangesDownThisPosition == null)
                {
                    yield return(currentRange);
                }
                else
                {
                    long skipRangesDownThisPositionVal = skipRangesDownThisPosition.Value;
                    if (currentRange.End < skipRangesDownThisPositionVal)                     // todo: < or <= ?
                    {
                        continue;
                    }
                    skipRangesDownThisPosition = null;
                    if (currentRange.Begin < skipRangesDownThisPositionVal)                     // todo: < or <= ?
                    {
                        yield return(new FileRange.Range(skipRangesDownThisPositionVal, currentRange.End));
                    }
                    else
                    {
                        yield return(currentRange);
                    }
                }
            }
        }

        IPositionedMessagesParser CreateParserForSearchableRange(
            FileRange.Range searchableRange,
            Func <IMessagesPostprocessor> messagesPostprocessor)
        {
            bool disableMultithreading = false;

            return(owner.CreateParser(new CreateParserParams(
                                          searchableRange.Begin, searchableRange,
                                          MessagesParserFlag.HintParserWillBeUsedForMassiveSequentialReading
                                          | (disableMultithreading ? MessagesParserFlag.DisableMultithreading : MessagesParserFlag.None),
                                          MessagesParserDirection.Forward,
                                          messagesPostprocessor)));
        }

        IEnumerable <FileRange.Range> EnumSearchableRangesCore(PlainTextMatcher matcher)
        {
            ITextAccess ta = new StreamTextAccess(rawStream, streamEncoding, textStreamPositioningParams);

            using (var tai = ta.OpenIterator(requestedRange.Begin, TextAccessDirection.Forward))
            {
                var lastRange = new FileRange.Range();
                foreach (var r in
                         IterateMatchRanges(
                             EnumCheckpoints(tai, matcher, progressAndCancellation, trace),
                             // todo: tune next parameter to find the value giving max performance.
                             // On one sample log bigger block was better than many small ones.
                             // Hence quite big threshold.
                             textStreamPositioningParams.AlignmentBlockSize * 8,
                             progressAndCancellation
                             )
                         .Select(r => PostprocessHintRange(r, lastRange))
                         )
                {
                    lastRange = r;
                    yield return(r);
                }
            }
        }

        FileRange.Range PostprocessHintRange(FileRange.Range r, FileRange.Range lastRange)
        {
            long fixedBegin = r.Begin;
            long fixedEnd   = r.End;

            int?inflateRangeBy = null;

            if (dejitteringParams != null && (parserParams.Flags & MessagesParserFlag.DisableDejitter) == 0)
            {
                inflateRangeBy = dejitteringParams.Value.JitterBufferSize;
            }

            aligmentSplitter.BeginSplittingSession(requestedRange, r.End, MessagesParserDirection.Forward);
            if (aligmentSplitter.GetCurrentMessageAndMoveToNextOne(aligmentCapture))
            {
                fixedEnd = aligmentCapture.EndPosition;
                if (inflateRangeBy != null)
                {
                    for (int i = 0; i < inflateRangeBy.Value; ++i)
                    {
                        if (!aligmentSplitter.GetCurrentMessageAndMoveToNextOne(aligmentCapture))
                        {
                            break;
                        }
                        fixedEnd = aligmentCapture.EndPosition;
                    }
                }
            }
            else
            {
                fixedEnd = requestedRange.End;
            }
            aligmentSplitter.EndSplittingSession();

            aligmentSplitter.BeginSplittingSession(requestedRange, fixedBegin, MessagesParserDirection.Backward);
            if (aligmentSplitter.GetCurrentMessageAndMoveToNextOne(aligmentCapture))
            {
                fixedBegin = aligmentCapture.BeginPosition;
                if (inflateRangeBy != null)
                {
                    for (int i = 0; i < inflateRangeBy.Value; ++i)
                    {
                        if (!aligmentSplitter.GetCurrentMessageAndMoveToNextOne(aligmentCapture))
                        {
                            break;
                        }
                        fixedBegin = aligmentCapture.BeginPosition;
                    }
                }
            }
            aligmentSplitter.EndSplittingSession();

            var ret = new FileRange.Range(fixedBegin, fixedEnd);

            ret = FileRange.Range.Intersect(ret, requestedRange).Common;
            var lastRangeIntersection = FileRange.Range.Intersect(ret, lastRange);

            if (lastRangeIntersection.RelativePosition == 0)
            {
                ret = lastRangeIntersection.Leftover1Right;
            }

            return(ret);
        }
Пример #15
0
        public void BeginSplittingSession(FileRange.Range range, long startPosition, MessagesParserDirection direction)
        {
            if (direction == MessagesParserDirection.Forward)
            {
                if (startPosition > range.Begin)
                {
                    long?fixedStartPosition = null;
                    underlyingSplitter.BeginSplittingSession(range, startPosition, MessagesParserDirection.Backward);
                    try
                    {
                        TextMessageCapture capt = new TextMessageCapture();
                        if (underlyingSplitter.GetCurrentMessageAndMoveToNextOne(capt))
                        {
                            fixedStartPosition = capt.EndPosition;
                        }
                    }
                    finally
                    {
                        underlyingSplitter.EndSplittingSession();
                    }
                    if (fixedStartPosition != null)
                    {
                        underlyingSplitter.BeginSplittingSession(range, fixedStartPosition.Value, direction);
                        try
                        {
                            TextMessageCapture capt = new TextMessageCapture();
                            while (underlyingSplitter.GetCurrentMessageAndMoveToNextOne(capt))
                            {
                                if (capt.BeginPosition >= startPosition)
                                {
                                    break;
                                }
                                fixedStartPosition = capt.EndPosition;
                            }
                        }
                        finally
                        {
                            underlyingSplitter.EndSplittingSession();
                        }
                        startPosition = fixedStartPosition.Value;
                    }
                }
            }
            else
            {
                if (startPosition < range.End)
                {
                    long?fixedStartPosition = null;
                    underlyingSplitter.BeginSplittingSession(range, startPosition, MessagesParserDirection.Forward);
                    try
                    {
                        TextMessageCapture capt = new TextMessageCapture();
                        if (underlyingSplitter.GetCurrentMessageAndMoveToNextOne(capt))
                        {
                            fixedStartPosition = capt.BeginPosition;
                        }
                    }
                    finally
                    {
                        underlyingSplitter.EndSplittingSession();
                    }
                    if (fixedStartPosition != null)
                    {
                        underlyingSplitter.BeginSplittingSession(range, fixedStartPosition.Value, direction);
                        try
                        {
                            TextMessageCapture capt = new TextMessageCapture();
                            while (underlyingSplitter.GetCurrentMessageAndMoveToNextOne(capt))
                            {
                                if (capt.EndPosition <= startPosition)
                                {
                                    break;
                                }
                                fixedStartPosition = capt.BeginPosition;
                            }
                        }
                        finally
                        {
                            underlyingSplitter.EndSplittingSession();
                        }
                        startPosition = fixedStartPosition.Value;
                    }
                }
            }

            underlyingSplitter.BeginSplittingSession(range, startPosition, direction);
        }