org.eclipse.linuxtools.tmf.core/src/org/eclipse/linuxtools/tmf/core/trace/TmfCheckpointIndexer.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012 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  *   Francois Chouinard - Initial API and implementation
  11  *******************************************************************************/
  12
  13 package org.eclipse.linuxtools.tmf.core.trace;
  14
  15 import java.util.ArrayList;
  16 import java.util.Collections;
  17 import java.util.List;
  18
  19 import org.eclipse.core.runtime.IProgressMonitor;
  20 import org.eclipse.core.runtime.IStatus;
  21 import org.eclipse.core.runtime.Status;
  22 import org.eclipse.core.runtime.jobs.Job;
  23 import org.eclipse.linuxtools.internal.tmf.core.Messages;
  24 import org.eclipse.linuxtools.tmf.core.component.TmfDataProvider;
  25 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
  26 import org.eclipse.linuxtools.tmf.core.event.ITmfTimestamp;
  27 import org.eclipse.linuxtools.tmf.core.event.TmfTimeRange;
  28 import org.eclipse.linuxtools.tmf.core.request.ITmfDataRequest;
  29 import org.eclipse.linuxtools.tmf.core.request.ITmfEventRequest;
  30 import org.eclipse.linuxtools.tmf.core.request.TmfDataRequest;
  31 import org.eclipse.linuxtools.tmf.core.request.TmfEventRequest;
  32 import org.eclipse.linuxtools.tmf.core.signal.TmfTraceUpdatedSignal;
  33
  34 /**
  35  * A simple indexer that manages the trace index as an array of trace
  36  * checkpoints. Checkpoints are stored at fixed intervals (event rank) in
  37  * ascending timestamp order.
  38  * <p>
  39  * The goal being to access a random trace event reasonably fast from the user's
  40  * standpoint, picking the right interval value becomes a trade-off between speed
  41  * and memory usage (a shorter inter-event interval is faster but requires more
  42  * checkpoints).
  43  * <p>
  44  * Locating a specific checkpoint is trivial for both rank (rank % interval) and
  45  * timestamp (bsearch in the array).
  46  *
  47  * @version 1.0
  48  * @author Francois Chouinard
  49  *
  50  * @see ITmfTrace
  51  * @see ITmfEvent
  52  */
  53 public class TmfCheckpointIndexer implements ITmfTraceIndexer {
  54
  55     // ------------------------------------------------------------------------
  56     // Attributes
  57     // ------------------------------------------------------------------------
  58
  59     /** The event trace to index */
  60     protected final ITmfTrace fTrace;
  61
  62     /** The interval between checkpoints */
  63     private final int fCheckpointInterval;
  64
  65     /** The event trace to index */
  66     private boolean fIsIndexing;
  67
  68     /**
  69      * The trace index. It is composed of checkpoints taken at intervals of
  70      * fCheckpointInterval events.
  71      */
  72     protected final List<ITmfCheckpoint> fTraceIndex;
  73
  74     /**
  75      * The indexing request
  76      */
  77     private ITmfEventRequest fIndexingRequest = null;
  78
  79     // ------------------------------------------------------------------------
  80     // Construction
  81     // ------------------------------------------------------------------------
  82
  83     /**
  84      * Basic constructor that uses the default trace block size as checkpoints
  85      * intervals
  86      *
  87      * @param trace the trace to index
  88      */
  89     public TmfCheckpointIndexer(final ITmfTrace trace) {
  90         this(trace, TmfDataProvider.DEFAULT_BLOCK_SIZE);
  91     }
  92
  93     /**
  94      * Full trace indexer
  95      *
  96      * @param trace the trace to index
  97      * @param interval the checkpoints interval
  98      */
  99     public TmfCheckpointIndexer(final ITmfTrace trace, final int interval) {
 100         fTrace = trace;
 101         fCheckpointInterval = interval;
 102         fTraceIndex = new ArrayList<ITmfCheckpoint>();
 103         fIsIndexing = false;
 104     }
 105
 106     /* (non-Javadoc)
 107      * @see org.eclipse.linuxtools.tmf.core.trace.ITmfTraceIndexer#dispose()
 108      */
 109     @Override
 110     public void dispose() {
 111         if ((fIndexingRequest != null) && !fIndexingRequest.isCompleted()) {
 112             fIndexingRequest.cancel();
 113             fTraceIndex.clear();
 114         }
 115     }
 116
 117     // ------------------------------------------------------------------------
 118     // ITmfTraceIndexer - isIndexing
 119     // ------------------------------------------------------------------------
 120
 121     /* (non-Javadoc)
 122      * @see org.eclipse.linuxtools.tmf.core.trace.ITmfTraceIndexer#isIndexing()
 123      */
 124     @Override
 125     public boolean isIndexing() {
 126         return fIsIndexing;
 127     }
 128
 129     // ------------------------------------------------------------------------
 130     // ITmfTraceIndexer - buildIndex
 131     // ------------------------------------------------------------------------
 132
 133     /* (non-Javadoc)
 134      *
 135      * The index is a list of contexts that point to events at regular interval
 136      * (rank-wise) in the trace. After it is built, the index can be used to
 137      * quickly access any event by rank or timestamp (using seekIndex()).
 138      *
 139      * The index is built simply by reading the trace
 140      *
 141      * @see org.eclipse.linuxtools.tmf.core.trace.ITmfTraceIndexer#buildIndex(long, org.eclipse.linuxtools.tmf.core.event.TmfTimeRange, boolean)
 142      */
 143     @Override
 144     public void buildIndex(final long offset, final TmfTimeRange range, final boolean waitForCompletion) {
 145
 146         // Don't do anything if we are already indexing
 147         synchronized (fTraceIndex) {
 148             if (fIsIndexing) {
 149                 return;
 150             }
 151             fIsIndexing = true;
 152         }
 153
 154         // The monitoring job
 155         final Job job = new Job("Indexing " + fTrace.getName() + "...") { //$NON-NLS-1$ //$NON-NLS-2$
 156             @Override
 157             protected IStatus run(final IProgressMonitor monitor) {
 158                 monitor.beginTask("", IProgressMonitor.UNKNOWN); //$NON-NLS-1$
 159                 while (!monitor.isCanceled()) {
 160                     try {
 161                         long prevNbEvents = fTrace.getNbEvents();
 162                         Thread.sleep(250);
 163                         long nbEvents = fTrace.getNbEvents();
 164                         setName(Messages.TmfCheckpointIndexer_Indexing + ' ' + fTrace.getName() + " (" + nbEvents + ")"); //$NON-NLS-1$ //$NON-NLS-2$
 165                         // setName doesn't refresh the UI, setTaskName does
 166                         long rate = (nbEvents - prevNbEvents) * 4;
 167                         monitor.setTaskName(rate + " " + Messages.TmfCheckpointIndexer_EventsPerSecond); //$NON-NLS-1$
 168                     } catch (final InterruptedException e) {
 169                         return Status.OK_STATUS;
 170                     }
 171                 }
 172                 monitor.done();
 173                 return Status.OK_STATUS;
 174             }
 175         };
 176         job.schedule();
 177
 178         // Build a background request for all the trace data. The index is
 179         // updated as we go by readNextEvent().
 180         fIndexingRequest = new TmfEventRequest(ITmfEvent.class,
 181                 range, offset, TmfDataRequest.ALL_DATA, fCheckpointInterval, ITmfDataRequest.ExecutionType.BACKGROUND)
 182         {
 183             @Override
 184             public void handleData(final ITmfEvent event) {
 185                 super.handleData(event);
 186                 if (event != null) {
 187                     // Update the trace status at regular intervals
 188                     if ((getNbRead() % fCheckpointInterval) == 0) {
 189                         updateTraceStatus();
 190                     }
 191                 }
 192             }
 193
 194             @Override
 195             public void handleSuccess() {
 196                 updateTraceStatus();
 197             }
 198
 199             @Override
 200             public void handleCompleted() {
 201                 job.cancel();
 202                 super.handleCompleted();
 203                 fIsIndexing = false;
 204             }
 205
 206             private void updateTraceStatus() {
 207                 if (fTrace.getNbEvents() > 0) {
 208                     signalNewTimeRange(fTrace.getStartTime(), fTrace.getEndTime());
 209                 }
 210             }
 211         };
 212
 213         // Submit the request and wait for completion if required
 214         fTrace.sendRequest(fIndexingRequest);
 215         if (waitForCompletion) {
 216             try {
 217                 fIndexingRequest.waitForCompletion();
 218             } catch (final InterruptedException e) {
 219             }
 220         }
 221     }
 222
 223     /**
 224      * Notify the interested parties that the trace time range has changed
 225      *
 226      * @param startTime the new start time
 227      * @param endTime the new end time
 228      */
 229     private void signalNewTimeRange(final ITmfTimestamp startTime, final ITmfTimestamp endTime) {
 230         fTrace.broadcast(new TmfTraceUpdatedSignal(fTrace, fTrace, new TmfTimeRange(startTime, endTime)));
 231     }
 232
 233     // ------------------------------------------------------------------------
 234     // ITmfTraceIndexer - updateIndex
 235     // ------------------------------------------------------------------------
 236
 237     /* (non-Javadoc)
 238      * @see org.eclipse.linuxtools.tmf.core.trace.ITmfTraceIndexer#updateIndex(org.eclipse.linuxtools.tmf.core.trace.ITmfContext, org.eclipse.linuxtools.tmf.core.event.ITmfTimestamp)
 239      */
 240     @Override
 241     public synchronized void updateIndex(final ITmfContext context, final ITmfTimestamp timestamp) {
 242         if ((context.getRank() % fCheckpointInterval) == 0) {
 243             // Determine the table position
 244             final long position = context.getRank() / fCheckpointInterval;
 245             // Add new entry at proper location (if empty)
 246             if (fTraceIndex.size() == position) {
 247                 fTraceIndex.add(new TmfCheckpoint(timestamp, context.getLocation()));
 248             }
 249         }
 250     }
 251
 252     // ------------------------------------------------------------------------
 253     // ITmfTraceIndexer - seekIndex
 254     // ------------------------------------------------------------------------
 255
 256     /* (non-Javadoc)
 257      * @see org.eclipse.linuxtools.tmf.core.trace.ITmfTraceIndexer#seekIndex(org.eclipse.linuxtools.tmf.core.event.ITmfTimestamp)
 258      */
 259     @Override
 260     public synchronized ITmfContext seekIndex(final ITmfTimestamp timestamp) {
 261
 262         // A null timestamp indicates to seek the first event
 263         if (timestamp == null) {
 264             return fTrace.seekEvent(0);
 265         }
 266
 267         // Find the checkpoint at or before the requested timestamp.
 268         // In the very likely event that the timestamp is not at a checkpoint
 269         // boundary, bsearch will return index = (- (insertion point + 1)).
 270         // It is then trivial to compute the index of the previous checkpoint.
 271         int index = Collections.binarySearch(fTraceIndex, new TmfCheckpoint(timestamp, null));
 272         if (index < 0) {
 273             index = Math.max(0, -(index + 2));
 274         } else {
 275             // If timestamp was in the list, use previous index to be able to find the
 276             // first event with the same timestamp before the checkpoint
 277             index = Math.max(0, index - 1);
 278         }
 279
 280         // Position the trace at the checkpoint
 281         return restoreCheckpoint(index);
 282     }
 283
 284     /* (non-Javadoc)
 285      * @see org.eclipse.linuxtools.tmf.core.trace.ITmfTraceIndexer#seekIndex(long)
 286      */
 287     @Override
 288     public ITmfContext seekIndex(final long rank) {
 289
 290         // A rank < 0 indicates to seek the first event
 291         if (rank < 0) {
 292             return fTrace.seekEvent(0);
 293         }
 294
 295         // Find the checkpoint at or before the requested rank.
 296         final int index = (int) rank / fCheckpointInterval;
 297
 298         // Position the trace at the checkpoint
 299         return restoreCheckpoint(index);
 300     }
 301
 302     /**
 303      * Position the trace at the given checkpoint
 304      *
 305      * @param checkpoint the checkpoint index
 306      * @return the corresponding context
 307      */
 308     private ITmfContext restoreCheckpoint(final int checkpoint) {
 309         ITmfLocation location = null;
 310         int index = 0;
 311         synchronized (fTraceIndex) {
 312             if (!fTraceIndex.isEmpty()) {
 313                 index = checkpoint;
 314                 if (index >= fTraceIndex.size()) {
 315                     index = fTraceIndex.size() - 1;
 316                 }
 317                 location = fTraceIndex.get(index).getLocation();
 318             }
 319         }
 320         final ITmfContext context = fTrace.seekEvent(location);
 321         context.setRank((long) index * fCheckpointInterval);
 322         return context;
 323     }
 324
 325     // ------------------------------------------------------------------------
 326     // Getters
 327     // ------------------------------------------------------------------------
 328
 329     /**
 330      * @return the trace index
 331      */
 332     protected List<ITmfCheckpoint> getTraceIndex() {
 333         return fTraceIndex;
 334     }
 335
 336 }