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