org.eclipse.linuxtools.tmf.ctf.core/src/org/eclipse/linuxtools/tmf/ctf/core/CtfIterator.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2014 Ericsson, École Polytechnique de Montréal
   3  *
   4  * All rights reserved. This program and the accompanying materials are made
   5  * 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  *   Matthew Khouzam - Initial API and implementation
  11  *   Florian Wininger - Performance improvements
  12  *******************************************************************************/
  13
  14 package org.eclipse.linuxtools.tmf.ctf.core;
  15
  16 import org.eclipse.linuxtools.ctf.core.trace.CTFReaderException;
  17 import org.eclipse.linuxtools.ctf.core.trace.CTFTraceReader;
  18 import org.eclipse.linuxtools.ctf.core.trace.CTFStreamInputReader;
  19 import org.eclipse.linuxtools.internal.tmf.ctf.core.Activator;
  20 import org.eclipse.linuxtools.tmf.core.trace.ITmfContext;
  21 import org.eclipse.linuxtools.tmf.core.trace.location.ITmfLocation;
  22
  23 /**
  24  * The CTF trace reader iterator.
  25  *
  26  * It doesn't reserve a file handle, so many iterators can be used without
  27  * worries of I/O errors or resource exhaustion.
  28  *
  29  * @author Matthew Khouzam
  30  */
  31 public class CtfIterator extends CTFTraceReader
  32         implements ITmfContext, Comparable<CtfIterator> {
  33
  34     /** An invalid location */
  35     public static final CtfLocation NULL_LOCATION = new CtfLocation(CtfLocation.INVALID_LOCATION);
  36
  37     private final CtfTmfTrace fTrace;
  38
  39     private CtfLocation fCurLocation;
  40     private long fCurRank;
  41
  42     private CtfLocation fPreviousLocation;
  43     private CtfTmfEvent fPreviousEvent;
  44
  45     // ------------------------------------------------------------------------
  46     // Constructors
  47     // ------------------------------------------------------------------------
  48
  49     /**
  50      * Create a new CTF trace iterator, which initially points at the first
  51      * event in the trace.
  52      *
  53      * @param trace
  54      *            The trace to iterate over
  55      * @throws CTFReaderException
  56      *             If the iterator couldn't not be instantiated, probably due to
  57      *             a read error.
  58      */
  59     public CtfIterator(CtfTmfTrace trace) throws CTFReaderException {
  60         super(trace.getCTFTrace());
  61         fTrace = trace;
  62         if (hasMoreEvents()) {
  63             fCurLocation = new CtfLocation(trace.getStartTime());
  64             fCurRank = 0;
  65         } else {
  66             setUnknownLocation();
  67         }
  68     }
  69
  70     /**
  71      * Create a new CTF trace iterator, which will initially point to the given
  72      * location/rank.
  73      *
  74      * @param trace
  75      *            The trace to iterate over
  76      * @param ctfLocationData
  77      *            The initial timestamp the iterator will be pointing to
  78      * @param rank
  79      *            The initial rank
  80      * @throws CTFReaderException
  81      *             If the iterator couldn't not be instantiated, probably due to
  82      *             a read error.
  83      * @since 2.0
  84      */
  85     public CtfIterator(CtfTmfTrace trace, CtfLocationInfo ctfLocationData, long rank)
  86             throws CTFReaderException {
  87         super(trace.getCTFTrace());
  88
  89         this.fTrace = trace;
  90         if (this.hasMoreEvents()) {
  91             this.fCurLocation = new CtfLocation(ctfLocationData);
  92             if (this.getCurrentEvent().getTimestamp().getValue() != ctfLocationData.getTimestamp()) {
  93                 this.seek(ctfLocationData);
  94                 this.fCurRank = rank;
  95             }
  96         } else {
  97             setUnknownLocation();
  98         }
  99     }
 100
 101     @Override
 102     public void dispose() {
 103         close();
 104     }
 105
 106     private void setUnknownLocation() {
 107         fCurLocation = NULL_LOCATION;
 108         fCurRank = UNKNOWN_RANK;
 109     }
 110
 111     // ------------------------------------------------------------------------
 112     // Accessors
 113     // ------------------------------------------------------------------------
 114
 115     /**
 116      * Return this iterator's trace.
 117      *
 118      * @return CtfTmfTrace The iterator's trace
 119      */
 120     public CtfTmfTrace getCtfTmfTrace() {
 121         return fTrace;
 122     }
 123
 124     /**
 125      * Return the current event pointed to by the iterator.
 126      *
 127      * @return CtfTmfEvent The current event
 128      */
 129     public synchronized CtfTmfEvent getCurrentEvent() {
 130         final CTFStreamInputReader top = super.getPrio().peek();
 131         if (top != null) {
 132             if (!fCurLocation.equals(fPreviousLocation)) {
 133                 fPreviousLocation = fCurLocation;
 134                 fPreviousEvent = CtfTmfEventFactory.createEvent(top.getCurrentEvent(),
 135                         top.getFilename(), fTrace);
 136             }
 137             return fPreviousEvent;
 138         }
 139         return null;
 140     }
 141
 142     /**
 143      * Seek this iterator to a given location.
 144      *
 145      * @param ctfLocationData
 146      *            The LocationData representing the position to seek to
 147      * @return boolean True if the seek was successful, false if there was an
 148      *         error seeking.
 149      * @since 2.0
 150      */
 151     public synchronized boolean seek(CtfLocationInfo ctfLocationData) {
 152         boolean ret = false;
 153
 154         /* Avoid the cost of seeking at the current location. */
 155         if (fCurLocation.getLocationInfo().equals(ctfLocationData)) {
 156             return super.hasMoreEvents();
 157         }
 158
 159         /* Adjust the timestamp depending on the trace's offset */
 160         long currTimestamp = ctfLocationData.getTimestamp();
 161         final long offsetTimestamp = this.getCtfTmfTrace().getCTFTrace().timestampNanoToCycles(currTimestamp);
 162         try {
 163             if (offsetTimestamp < 0) {
 164                 ret = super.seek(0L);
 165             } else {
 166                 ret = super.seek(offsetTimestamp);
 167             }
 168         } catch (CTFReaderException e) {
 169             Activator.getDefault().logError(e.getMessage(), e);
 170             return false;
 171         }
 172         /*
 173          * Check if there is already one or more events for that timestamp, and
 174          * assign the location index correctly
 175          */
 176         long index = 0;
 177         final CtfTmfEvent currentEvent = this.getCurrentEvent();
 178         if (currentEvent != null) {
 179             currTimestamp = currentEvent.getTimestamp().getValue();
 180
 181             for (long i = 0; i < ctfLocationData.getIndex(); i++) {
 182                 if (currTimestamp == currentEvent.getTimestamp().getValue()) {
 183                     index++;
 184                 } else {
 185                     index = 0;
 186                 }
 187                 this.advance();
 188             }
 189         } else {
 190             ret = false;
 191         }
 192         /* Seek the current location accordingly */
 193         if (ret) {
 194             fCurLocation = new CtfLocation(new CtfLocationInfo(getCurrentEvent().getTimestamp().getValue(), index));
 195         } else {
 196             fCurLocation = NULL_LOCATION;
 197         }
 198
 199         return ret;
 200     }
 201
 202     // ------------------------------------------------------------------------
 203     // CTFTraceReader
 204     // ------------------------------------------------------------------------
 205
 206     @Override
 207     public boolean seek(long timestamp) {
 208         return seek(new CtfLocationInfo(timestamp, 0));
 209     }
 210
 211     @Override
 212     public synchronized boolean advance() {
 213         long index = fCurLocation.getLocationInfo().getIndex();
 214         long timestamp = fCurLocation.getLocationInfo().getTimestamp();
 215         boolean ret = false;
 216         try {
 217             ret = super.advance();
 218         } catch (CTFReaderException e) {
 219             Activator.getDefault().logError(e.getMessage(), e);
 220         }
 221
 222         if (ret) {
 223             final long timestampValue = getCurrentEvent().getTimestamp().getValue();
 224             if (timestamp == timestampValue) {
 225                 fCurLocation = new CtfLocation(timestampValue, index + 1);
 226             } else {
 227                 fCurLocation = new CtfLocation(timestampValue, 0L);
 228             }
 229         } else {
 230             fCurLocation = NULL_LOCATION;
 231         }
 232         return ret;
 233     }
 234
 235     // ------------------------------------------------------------------------
 236     // ITmfContext
 237     // ------------------------------------------------------------------------
 238
 239     @Override
 240     public long getRank() {
 241         return fCurRank;
 242     }
 243
 244     @Override
 245     public void setRank(long rank) {
 246         fCurRank = rank;
 247     }
 248
 249     @Override
 250     public void increaseRank() {
 251         /* Only increase the rank if it's valid */
 252         if (hasValidRank()) {
 253             fCurRank++;
 254         }
 255     }
 256
 257     @Override
 258     public boolean hasValidRank() {
 259         return (getRank() >= 0);
 260     }
 261
 262     /**
 263      * @since 3.0
 264      */
 265     @Override
 266     public void setLocation(ITmfLocation location) {
 267         // FIXME alex: isn't there a cleaner way than a cast here?
 268         fCurLocation = (CtfLocation) location;
 269         seek(((CtfLocation) location).getLocationInfo());
 270     }
 271
 272     @Override
 273     public CtfLocation getLocation() {
 274         return fCurLocation;
 275     }
 276
 277     // ------------------------------------------------------------------------
 278     // Comparable
 279     // ------------------------------------------------------------------------
 280
 281     @Override
 282     public int compareTo(final CtfIterator o) {
 283         if (getRank() < o.getRank()) {
 284             return -1;
 285         } else if (getRank() > o.getRank()) {
 286             return 1;
 287         }
 288         return 0;
 289     }
 290
 291     // ------------------------------------------------------------------------
 292     // Object
 293     // ------------------------------------------------------------------------
 294
 295     @Override
 296     public int hashCode() {
 297         final int prime = 31;
 298         int result = super.hashCode();
 299         result = (prime * result)
 300                 + ((fTrace == null) ? 0 : fTrace.hashCode());
 301         result = (prime * result)
 302                 + ((fCurLocation == null) ? 0 : fCurLocation.hashCode());
 303         result = (prime * result) + (int) (fCurRank ^ (fCurRank >>> 32));
 304         return result;
 305     }
 306
 307     @Override
 308     public boolean equals(Object obj) {
 309         if (this == obj) {
 310             return true;
 311         }
 312         if (!super.equals(obj)) {
 313             return false;
 314         }
 315         if (!(obj instanceof CtfIterator)) {
 316             return false;
 317         }
 318         CtfIterator other = (CtfIterator) obj;
 319         if (fTrace == null) {
 320             if (other.fTrace != null) {
 321                 return false;
 322             }
 323         } else if (!fTrace.equals(other.fTrace)) {
 324             return false;
 325         }
 326         if (fCurLocation == null) {
 327             if (other.fCurLocation != null) {
 328                 return false;
 329             }
 330         } else if (!fCurLocation.equals(other.fCurLocation)) {
 331             return false;
 332         }
 333         if (fCurRank != other.fCurRank) {
 334             return false;
 335         }
 336         return true;
 337     }
 338 }