org.eclipse.linuxtools.lttng.ui/src/org/eclipse/linuxtools/lttng/ui/views/histogram/HistogramRequest.java

   1 /*******************************************************************************
   2  * Copyright (c) 2009 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   William Bourque - Initial API and implementation
  11  *******************************************************************************/
  12 package org.eclipse.linuxtools.lttng.ui.views.histogram;
  13
  14 import org.eclipse.linuxtools.lttng.event.LttngEvent;
  15 import org.eclipse.linuxtools.tmf.event.TmfEvent;
  16 import org.eclipse.linuxtools.tmf.event.TmfTimeRange;
  17 import org.eclipse.linuxtools.tmf.request.TmfEventRequest;
  18
  19 /**
  20  * <b><u>HistogramRequest</u></b>
  21  * <p>
  22  * Request class, to perform a request to TMF for the histograms.
  23  * <p>
  24  */
  25 public class HistogramRequest extends TmfEventRequest<LttngEvent> {
  26         protected HistogramContent histogramContent = null;
  27
  28         protected Integer       lastInterval = 0;
  29         protected Long          lastRangeTime = 0L;
  30         protected Long          nbEventsInInterval = 1L;
  31
  32         protected Integer       nbIntervalNotEmpty = 1;
  33         protected Integer       nbEventRead = 0;
  34
  35         protected Integer       lastDrawPosition = 0;
  36
  37         protected Boolean       requestCompleted = false;
  38
  39         protected HistogramCanvas parentCanvas = null;
  40
  41         /**
  42          * Constructor for HistogramRequest.<p>
  43          * Prepare the request in TMF and reset the histogram content.
  44          *
  45          * @param range                         Range of the request.
  46          * @param nbRequested           Nb events requested. Can be "Infinity" for all.
  47          * @param newParentCanvas       HistogramCanvas related to the request.
  48          * @param timeInterval          Time interval to consider (i.e. : 1 interval is 1 bar in the histogram)
  49          *
  50          * @see org.eclipse.linuxtools.tmf.request.TmfEventRequest
  51          */
  52         public HistogramRequest(TmfTimeRange range, Integer nbRequested, HistogramCanvas newParentCanvas, Long timeInterval) {
  53         super((Class<LttngEvent>)LttngEvent.class, range, nbRequested, HistogramConstant.MAX_EVENTS_PER_READ);
  54
  55         // *** FIXME ***
  56         // This does not work! The request won't be processed or the number of events returned is wrong!
  57         // We cannot use this !
  58                 //super((Class<LttngEvent>)dataType, range);
  59
  60         parentCanvas = newParentCanvas;
  61         histogramContent = parentCanvas.getHistogramContent();
  62
  63         // Reset the content of the HistogramContent... the given data better be valid or this will fail.
  64         histogramContent.clearContentData();
  65         histogramContent.resetTable(range.getStartTime().getValue(), range.getEndTime().getValue(), timeInterval);
  66
  67         lastRangeTime = range.getStartTime().getValue();
  68
  69         // Notify the UI even before the request started, so we set the timestamp already.
  70         parentCanvas.notifyParentUpdatedInformationAsynchronously();
  71     }
  72
  73         /**
  74          * HandleData function : will be called by TMF each time a new event is receive for the request.<p>
  75          * Calculation for the content is done here.
  76          */
  77         @Override
  78     public void handleData() {
  79         TmfEvent[] result = getData();
  80         TmfEvent[] evt = new TmfEvent[1];
  81
  82         evt[0] = (result.length > 0) ? result[0] : null;
  83
  84         // *** FIXME ***
  85         // *** EVIL BUG ***
  86         // The request by timerange only does not work! (see constructor above)
  87         //      However, the request with number of events will loop until it reach its number or EOF
  88         //  We have to filter out ourself the extra useless events!
  89         //
  90         if ( (evt[0] != null) && (requestCompleted == false) ) {
  91                 LttngEvent tmpEvent = (LttngEvent)evt[0];
  92
  93                 // This check is linked to the evil fix mentionned above
  94                 if ( ( tmpEvent.getTimestamp().getValue() >= histogramContent.getStartTime() ) &&
  95                          ( tmpEvent.getTimestamp().getValue() <= histogramContent.getEndTime() ) )
  96                 {
  97
  98                         // Distance (in time) between this event and the last one we read
  99                         long distance = ( tmpEvent.getTimestamp().getValue() - lastRangeTime );
 100
 101                         // Check if we changed of interval (the distance is higher than the interval time)
 102                                 if  ( distance > histogramContent.getElementsTimeInterval() ) {
 103
 104                                         histogramContent.getElementByIndex(lastInterval).intervalNbEvents = nbEventsInInterval;
 105                                         lastRangeTime = tmpEvent.getTimestamp().getValue();
 106
 107                                         // * NOTE *
 108                                         // We can skip several interval at once, so we need to find what was our interval now
 109                                         lastInterval = (int)((lastRangeTime - histogramContent.getStartTime()) / histogramContent.getElementsTimeInterval() );
 110
 111                                         // *** HACK ***
 112                                         // Because of the threads, weird phenomenons seem to happen here, like a position after the
 113                                         //       element range because another request was issued.
 114                                         // This enforce the position but may result in slightly inconsistent result (i.e. a weird misplaced bar sometime).
 115                                         if ( lastInterval < 0 ) {
 116                                                 lastInterval = 0;
 117                                         }
 118                                         else if ( lastInterval >= histogramContent.getNbElement() ) {
 119                                                 lastInterval = (histogramContent.getNbElement()-1);
 120                                         }
 121
 122                                         // * NOTE *
 123                                         // We save the time we have here. This mean only the FIRST time read in an interval will be saved.
 124                                         histogramContent.getElementByIndex(lastInterval).firstIntervalTimestamp = lastRangeTime;
 125                                         histogramContent.setReadyUpToPosition(lastInterval);
 126
 127                                         nbIntervalNotEmpty++;
 128                                         nbEventsInInterval = 1L;
 129                                 }
 130                                 // We are still in the same interval, just keep counting
 131                                 else {
 132                                         nbEventsInInterval++;
 133                                         if ( nbEventsInInterval > histogramContent.getHeighestEventCount() ) {
 134                                                 histogramContent.setHeighestEventCount(nbEventsInInterval);
 135                                         }
 136                                 }
 137
 138                                 nbEventRead++;
 139
 140                                 // Call an asynchronous redraw every REDRAW_EVERY_NB_EVENTS events
 141                                 // That way we don't need to wait until to end to have something on the screen
 142                                 if ( nbEventRead % HistogramConstant.REDRAW_EVERY_NB_EVENTS == 0 ) {
 143                                         redrawAsyncronously();
 144                                 }
 145                 }
 146                 else {
 147                         //System.out.println("Requested Timerange is : " + histogramContent.getStartTime() + " / " + histogramContent.getEndTime());
 148                         //System.out.println("Time is : " + tmpEvent.getTimestamp().getValue());
 149                         // *** FIXME ***
 150                 // *** EVIL FIX ***
 151                 // Because of the other evil bug (see above), we have to ignore extra useless events we will get
 152                         // However, we might be far away from the end so we better start a redraw now
 153                         if (tmpEvent.getTimestamp().getValue() >= histogramContent.getEndTime()) {
 154                                 redrawAsyncronously();
 155                                 requestCompleted = true;
 156                         }
 157                 }
 158                 }
 159     }
 160
 161         /**
 162          * Function that is called when the request completed (successful or not).<p>
 163          * Update information and redraw the screen.
 164          */
 165     @Override
 166     public void handleCompleted() {
 167         parentCanvas.notifyParentUpdatedInformationAsynchronously();
 168                 redrawAsyncronously();
 169     }
 170
 171     /**
 172          * Function that is called when the request completed successfully.<p>
 173          */
 174     @Override
 175     public void handleSuccess() {
 176         // Nothing different from completed.
 177     }
 178
 179     /**
 180          * Function that is called when the request completed in failure.<p>
 181          */
 182     @Override
 183     public void handleFailure() {
 184         // Nothing different from cancel.
 185     }
 186
 187     /**
 188          * Function that is called when the request was cancelled.<p>
 189          * Redraw and set the requestCompleted flag to true;
 190          */
 191     @Override
 192     public void handleCancel() {
 193         redrawAsyncronously();
 194                 requestCompleted = true;
 195     }
 196
 197     /**
 198          * Update the HistogramContent with the latest information.<p>
 199          * This will perform some calculation that might be a bit harsh so it should'nt be called too often.
 200          */
 201     public void updateEventsInfo() {
 202         // *** Note ***
 203         // The average number of event is calculated while skipping empty interval if asked
 204         int averageNumberOfEvents = 0;
 205         if ( HistogramConstant.SKIP_EMPTY_INTERVALS_WHEN_CALCULATING_AVERAGE ) {
 206                 averageNumberOfEvents = nbEventRead / nbIntervalNotEmpty;
 207         }
 208         else {
 209                 averageNumberOfEvents = nbEventRead / histogramContent.getNbElement();
 210         }
 211         histogramContent.setAverageNumberOfEvents(averageNumberOfEvents);
 212
 213         // It is possible that the height factor didn't change;
 214         //              If not, we only need to redraw the updated section, no the whole content
 215         // Save the actual height, recalculate the height and check if there was any changes
 216         double previousHeightFactor = histogramContent.getHeightFactor();
 217         histogramContent.recalculateHeightFactor();
 218         if ( histogramContent.getHeightFactor() != previousHeightFactor ) {
 219                         histogramContent.recalculateEventHeight();
 220         }
 221         else {
 222                 histogramContent.recalculateEventHeightInInterval(lastDrawPosition, histogramContent.getReadyUpToPosition());
 223         }
 224
 225         lastDrawPosition = histogramContent.getReadyUpToPosition();
 226     }
 227
 228     /**
 229          * Perform an asynchonous redraw of the screen.
 230          */
 231     public void redrawAsyncronously() {
 232         updateEventsInfo();
 233         // Canvas redraw is already asynchronous
 234         parentCanvas.redrawAsynchronously();
 235     }
 236
 237 }