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

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2013 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.request.ITmfDataRequest;
  27 import org.eclipse.linuxtools.tmf.core.request.ITmfEventRequest;
  28 import org.eclipse.linuxtools.tmf.core.request.TmfDataRequest;
  29 import org.eclipse.linuxtools.tmf.core.request.TmfEventRequest;
  30 import org.eclipse.linuxtools.tmf.core.signal.TmfTraceUpdatedSignal;
  31 import org.eclipse.linuxtools.tmf.core.timestamp.ITmfTimestamp;
  32 import org.eclipse.linuxtools.tmf.core.timestamp.TmfTimeRange;
  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     @Override
 107     public void dispose() {
 108         if ((fIndexingRequest != null) && !fIndexingRequest.isCompleted()) {
 109             fIndexingRequest.cancel();
 110             fTraceIndex.clear();
 111         }
 112     }
 113
 114     // ------------------------------------------------------------------------
 115     // ITmfTraceIndexer - isIndexing
 116     // ------------------------------------------------------------------------
 117
 118     @Override
 119     public boolean isIndexing() {
 120         return fIsIndexing;
 121     }
 122
 123     // ------------------------------------------------------------------------
 124     // ITmfTraceIndexer - buildIndex
 125     // ------------------------------------------------------------------------
 126
 127     /**
 128      * @since 2.0
 129      */
 130     @Override
 131     public void buildIndex(final long offset, final TmfTimeRange range, final boolean waitForCompletion) {
 132
 133         // Don't do anything if we are already indexing
 134         synchronized (fTraceIndex) {
 135             if (fIsIndexing) {
 136                 return;
 137             }
 138             fIsIndexing = true;
 139         }
 140
 141         // The monitoring job
 142         final Job job = new Job("Indexing " + fTrace.getName() + "...") { //$NON-NLS-1$ //$NON-NLS-2$
 143             @Override
 144             protected IStatus run(final IProgressMonitor monitor) {
 145                 monitor.beginTask("", IProgressMonitor.UNKNOWN); //$NON-NLS-1$
 146                 while (!monitor.isCanceled()) {
 147                     try {
 148                         long prevNbEvents = fTrace.getNbEvents();
 149                         Thread.sleep(250);
 150                         long nbEvents = fTrace.getNbEvents();
 151                         setName(Messages.TmfCheckpointIndexer_Indexing + ' ' + fTrace.getName() + " (" + nbEvents + ")"); //$NON-NLS-1$ //$NON-NLS-2$
 152                         // setName doesn't refresh the UI, setTaskName does
 153                         long rate = (nbEvents - prevNbEvents) * 4;
 154                         monitor.setTaskName(rate + " " + Messages.TmfCheckpointIndexer_EventsPerSecond); //$NON-NLS-1$
 155                     } catch (final InterruptedException e) {
 156                         return Status.OK_STATUS;
 157                     }
 158                 }
 159                 monitor.done();
 160                 return Status.OK_STATUS;
 161             }
 162         };
 163         job.schedule();
 164
 165         // Build a background request for all the trace data. The index is
 166         // updated as we go by readNextEvent().
 167         fIndexingRequest = new TmfEventRequest(ITmfEvent.class,
 168                 range, offset, TmfDataRequest.ALL_DATA,
 169                 ITmfDataRequest.ExecutionType.BACKGROUND) {
 170             @Override
 171             public void handleData(final ITmfEvent event) {
 172                 super.handleData(event);
 173                 if (event != null) {
 174                     // Update the trace status at regular intervals
 175                     if ((getNbRead() % fCheckpointInterval) == 0) {
 176                         updateTraceStatus();
 177                     }
 178                 }
 179             }
 180
 181             @Override
 182             public void handleSuccess() {
 183                 updateTraceStatus();
 184             }
 185
 186             @Override
 187             public void handleCompleted() {
 188                 job.cancel();
 189                 super.handleCompleted();
 190                 fIsIndexing = false;
 191             }
 192
 193             private void updateTraceStatus() {
 194                 if (fTrace.getNbEvents() > 0) {
 195                     signalNewTimeRange(fTrace.getStartTime(), fTrace.getEndTime());
 196                 }
 197             }
 198         };
 199
 200         // Submit the request and wait for completion if required
 201         fTrace.sendRequest(fIndexingRequest);
 202         if (waitForCompletion) {
 203             try {
 204                 fIndexingRequest.waitForCompletion();
 205             } catch (final InterruptedException e) {
 206             }
 207         }
 208     }
 209
 210     /**
 211      * Notify the interested parties that the trace time range has changed
 212      *
 213      * @param startTime the new start time
 214      * @param endTime the new end time
 215      */
 216     private void signalNewTimeRange(final ITmfTimestamp startTime, final ITmfTimestamp endTime) {
 217         fTrace.broadcast(new TmfTraceUpdatedSignal(fTrace, fTrace, new TmfTimeRange(startTime, endTime)));
 218     }
 219
 220     // ------------------------------------------------------------------------
 221     // ITmfTraceIndexer - updateIndex
 222     // ------------------------------------------------------------------------
 223
 224     /**
 225      * @since 2.0
 226      */
 227     @Override
 228     public synchronized void updateIndex(final ITmfContext context, final ITmfTimestamp timestamp) {
 229         if ((context.getRank() % fCheckpointInterval) == 0) {
 230             // Determine the table position
 231             final long position = context.getRank() / fCheckpointInterval;
 232             // Add new entry at proper location (if empty)
 233             if (fTraceIndex.size() == position) {
 234                 fTraceIndex.add(new TmfCheckpoint(timestamp, context.getLocation()));
 235             }
 236         }
 237     }
 238
 239     // ------------------------------------------------------------------------
 240     // ITmfTraceIndexer - seekIndex
 241     // ------------------------------------------------------------------------
 242
 243     /**
 244      * @since 2.0
 245      */
 246     @Override
 247     public synchronized ITmfContext seekIndex(final ITmfTimestamp timestamp) {
 248
 249         // A null timestamp indicates to seek the first event
 250         if (timestamp == null) {
 251             return fTrace.seekEvent(0);
 252         }
 253
 254         // Find the checkpoint at or before the requested timestamp.
 255         // In the very likely event that the timestamp is not at a checkpoint
 256         // boundary, bsearch will return index = (- (insertion point + 1)).
 257         // It is then trivial to compute the index of the previous checkpoint.
 258         int index = Collections.binarySearch(fTraceIndex, new TmfCheckpoint(timestamp, null));
 259         if (index < 0) {
 260             index = Math.max(0, -(index + 2));
 261         } else {
 262             // If timestamp was in the list, use previous index to be able to find the
 263             // first event with the same timestamp before the checkpoint
 264             index = Math.max(0, index - 1);
 265         }
 266
 267         // Position the trace at the checkpoint
 268         return restoreCheckpoint(index);
 269     }
 270
 271     @Override
 272     public ITmfContext seekIndex(final long rank) {
 273
 274         // A rank < 0 indicates to seek the first event
 275         if (rank < 0) {
 276             return fTrace.seekEvent(0);
 277         }
 278
 279         // Find the checkpoint at or before the requested rank.
 280         final int index = (int) rank / fCheckpointInterval;
 281
 282         // Position the trace at the checkpoint
 283         return restoreCheckpoint(index);
 284     }
 285
 286     /**
 287      * Position the trace at the given checkpoint
 288      *
 289      * @param checkpoint the checkpoint index
 290      * @return the corresponding context
 291      */
 292     private ITmfContext restoreCheckpoint(final int checkpoint) {
 293         ITmfLocation location = null;
 294         int index = 0;
 295         synchronized (fTraceIndex) {
 296             if (!fTraceIndex.isEmpty()) {
 297                 index = checkpoint;
 298                 if (index >= fTraceIndex.size()) {
 299                     index = fTraceIndex.size() - 1;
 300                 }
 301                 location = fTraceIndex.get(index).getLocation();
 302             }
 303         }
 304         final ITmfContext context = fTrace.seekEvent(location);
 305         context.setRank((long) index * fCheckpointInterval);
 306         return context;
 307     }
 308
 309     // ------------------------------------------------------------------------
 310     // Getters
 311     // ------------------------------------------------------------------------
 312
 313     /**
 314      * @return the trace index
 315      */
 316     protected List<ITmfCheckpoint> getTraceIndex() {
 317         return fTraceIndex;
 318     }
 319
 320 }