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