tmf/org.eclipse.tracecompass.tmf.ui/src/org/eclipse/tracecompass/tmf/ui/viewers/events/TmfEventsCache.java

   1 /*******************************************************************************
   2  * Copyright (c) 2011, 2014 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  *   Patrick Tasse - Initial API and implementation
  11  *   Bernd Hufmann - Add support for event collapsing
  12  ******************************************************************************/
  13
  14 package org.eclipse.tracecompass.tmf.ui.viewers.events;
  15
  16 import java.util.ArrayList;
  17 import java.util.Arrays;
  18 import java.util.List;
  19
  20 import org.eclipse.core.runtime.IProgressMonitor;
  21 import org.eclipse.core.runtime.IStatus;
  22 import org.eclipse.core.runtime.Status;
  23 import org.eclipse.core.runtime.jobs.Job;
  24 import org.eclipse.tracecompass.internal.tmf.core.filter.TmfCollapseFilter;
  25 import org.eclipse.tracecompass.internal.tmf.ui.Activator;
  26 import org.eclipse.tracecompass.tmf.core.component.ITmfEventProvider;
  27 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  28 import org.eclipse.tracecompass.tmf.core.event.ITmfEventField;
  29 import org.eclipse.tracecompass.tmf.core.event.ITmfEventType;
  30 import org.eclipse.tracecompass.tmf.core.filter.ITmfFilter;
  31 import org.eclipse.tracecompass.tmf.core.request.ITmfEventRequest;
  32 import org.eclipse.tracecompass.tmf.core.request.TmfEventRequest;
  33 import org.eclipse.tracecompass.tmf.core.timestamp.ITmfTimestamp;
  34 import org.eclipse.tracecompass.tmf.core.timestamp.TmfTimeRange;
  35 import org.eclipse.tracecompass.tmf.core.trace.ITmfTrace;
  36
  37 /**
  38  * The generic TMF Events table events cache
  39  *
  40  * This can help avoid re-reading the trace when the user scrolls a window,
  41  * for example.
  42  *
  43  * @author Patrick Tasse
  44  */
  45 public class TmfEventsCache {
  46
  47     /**
  48      * The generic TMF Events table cached event.
  49      *
  50      * @author Patrick Tasse
  51      */
  52     public static class CachedEvent implements ITmfEvent {
  53         /**
  54          * Event reference.
  55          *
  56          * When {@link TmfCollapseFilter} is active then it's event reference
  57          * of the first event of repeated events.
  58          */
  59         ITmfEvent event;
  60         /**
  61          * Events rank.
  62          *
  63          * When {@link TmfCollapseFilter} is active then it's event rank of the
  64          * first event of repeated events.
  65          */
  66         long rank;
  67         /**
  68          * Number times event is repeated. Updated by using {@link TmfCollapseFilter}
  69          */
  70         long repeatCount;
  71
  72         /**
  73          * Constructor for new cached events.
  74          *
  75          * @param iTmfEvent
  76          *            The original trace event
  77          * @param rank
  78          *            The rank of this event in the trace
  79          */
  80         public CachedEvent (ITmfEvent iTmfEvent, long rank) {
  81             this.event = iTmfEvent;
  82             this.rank = rank;
  83         }
  84
  85         @Override
  86         public <T> T getAdapter(Class<T> adapterType) {
  87             return event.getAdapter(adapterType);
  88         }
  89
  90         @Override
  91         public ITmfTrace getTrace() {
  92             return event.getTrace();
  93         }
  94
  95         @Override
  96         public long getRank() {
  97             return event.getRank();
  98         }
  99
 100         /**
 101          * @since 1.0
 102          */
 103         @Override
 104         public String getName() {
 105             return event.getName();
 106         }
 107
 108         @Override
 109         public ITmfTimestamp getTimestamp() {
 110             return event.getTimestamp();
 111         }
 112
 113         @Override
 114         public ITmfEventType getType() {
 115             return event.getType();
 116         }
 117
 118         @Override
 119         public ITmfEventField getContent() {
 120             return event.getContent();
 121         }
 122     }
 123
 124     private final CachedEvent[] fCache;
 125     private final int fCacheSize;
 126     private int fCacheStartIndex = 0;
 127     private int fCacheEndIndex   = 0;
 128
 129     private ITmfTrace fTrace;
 130     private final TmfEventsTable fTable;
 131     private ITmfFilter fFilter;
 132     private final List<Integer> fFilterIndex = new ArrayList<>(); // contains the event rank at each 'cache size' filtered events
 133
 134     /**
 135      * Constructor for the event cache
 136      *
 137      * @param cacheSize
 138      *            The size of the cache, in number of events
 139      * @param table
 140      *            The Events table this cache will cover
 141      */
 142     public TmfEventsCache(int cacheSize, TmfEventsTable table) {
 143         fCacheSize = cacheSize;
 144         fCache = new CachedEvent[cacheSize * 2]; // the cache holds two blocks of cache size
 145         fTable = table;
 146     }
 147
 148     /**
 149      * Assign a new trace to this events cache. This clears the current
 150      * contents.
 151      *
 152      * @param trace
 153      *            The trace to assign.
 154      */
 155     public void setTrace(ITmfTrace trace) {
 156         fTrace = trace;
 157         clear();
 158     }
 159
 160     /**
 161      * Clear the current contents of this cache.
 162      */
 163     public synchronized void clear() {
 164         if (job != null && job.getState() != Job.NONE) {
 165             job.cancel();
 166         }
 167         Arrays.fill(fCache, null);
 168         fCacheStartIndex = 0;
 169         fCacheEndIndex = 0;
 170         fFilterIndex.clear();
 171     }
 172
 173     /**
 174      * Apply a filter on this event cache. This clears the current cache
 175      * contents.
 176      *
 177      * @param filter
 178      *            The ITmfFilter to apply.
 179      */
 180     public void applyFilter(ITmfFilter filter) {
 181         fFilter = filter;
 182         clear();
 183     }
 184
 185     /**
 186      * Clear the current filter on this cache. This also clears the current
 187      * cache contents.
 188      */
 189     public void clearFilter() {
 190         fFilter = null;
 191         clear();
 192     }
 193
 194     /**
 195      * Get an event from the cache. If the cache does not contain the event,
 196      * a cache population request is triggered.
 197      *
 198      * @param index
 199      *            The index of this event in the cache
 200      * @return The cached event, or 'null' if the event is not in the cache
 201      */
 202     public synchronized CachedEvent getEvent(int index) {
 203         if ((index >= fCacheStartIndex) && (index < fCacheEndIndex)) {
 204             int i = index - fCacheStartIndex;
 205             return fCache[i];
 206         }
 207         populateCache(index);
 208         return null;
 209     }
 210
 211     /**
 212      * Peek an event in the cache. Does not trigger cache population.
 213      *
 214      * @param index
 215      *            Index of the event to peek
 216      * @return The cached event, or 'null' if the event is not in the cache
 217      */
 218     public synchronized CachedEvent peekEvent(int index) {
 219         if ((index >= fCacheStartIndex) && (index < fCacheEndIndex)) {
 220             int i = index - fCacheStartIndex;
 221             return fCache[i];
 222         }
 223         return null;
 224     }
 225
 226     /**
 227      * Add a trace event to the cache.
 228      *
 229      * @param event
 230      *            The original trace event to be cached
 231      * @param rank
 232      *            The rank of this event in the trace
 233      * @param index
 234      *            The index this event will occupy in the cache
 235      */
 236     public synchronized void storeEvent(ITmfEvent event, long rank, int index) {
 237         if (index == fCacheEndIndex) {
 238             int i = index - fCacheStartIndex;
 239             if (i < fCache.length) {
 240                 fCache[i] = new CachedEvent(event, rank);
 241                 fCacheEndIndex++;
 242             }
 243         }
 244         if ((fFilter != null) && ((index % fCacheSize) == 0)) {
 245             int i = index / fCacheSize;
 246             fFilterIndex.add(i, Integer.valueOf((int) rank));
 247         }
 248     }
 249
 250     /**
 251      * Update event repeat count at index
 252      *
 253      * @param index
 254      *            The index this event occupies in the cache
 255      */
 256     public synchronized void updateCollapsedEvent(int index) {
 257         int i = index - fCacheStartIndex;
 258         if (i < fCache.length) {
 259             fCache[i].repeatCount++;
 260         }
 261     }
 262
 263     /**
 264      * Get the cache index of an event from his rank in the trace. This will
 265      * take in consideration any filter that might be applied.
 266      *
 267      * @param rank
 268      *            The rank of the event in the trace
 269      * @return The position (index) this event should use once cached
 270      */
 271     public int getFilteredEventIndex(final long rank) {
 272         int current;
 273         int startRank;
 274         TmfEventRequest request;
 275         final ITmfFilter filter = fFilter;
 276         synchronized (this) {
 277             int start = 0;
 278             int end = fFilterIndex.size();
 279
 280             if ((fCacheEndIndex - fCacheStartIndex) > 1) {
 281                 if (rank < fCache[0].rank) {
 282                     end = (fCacheStartIndex / fCacheSize) + 1;
 283                 } else if (rank > fCache[fCacheEndIndex - fCacheStartIndex - 1].rank) {
 284                     start = fCacheEndIndex / fCacheSize;
 285                 } else {
 286                     for (int i = 0; i < (fCacheEndIndex - fCacheStartIndex); i++) {
 287                         if (fCache[i].rank >= rank) {
 288                             return fCacheStartIndex + i;
 289                         }
 290                     }
 291                     return fCacheEndIndex;
 292                 }
 293             }
 294
 295             current = (start + end) / 2;
 296             while (current != start) {
 297                 if (rank < fFilterIndex.get(current)) {
 298                     end = current;
 299                     current = (start + end) / 2;
 300                 } else {
 301                     start = current;
 302                     current = (start + end) / 2;
 303                 }
 304             }
 305             startRank = fFilterIndex.size() > 0 ? fFilterIndex.get(current) : 0;
 306         }
 307
 308         final int index = current * fCacheSize;
 309
 310         class DataRequest extends TmfEventRequest {
 311             ITmfFilter requestFilter;
 312             int requestRank;
 313             int requestIndex;
 314
 315             DataRequest(Class<? extends ITmfEvent> dataType, ITmfFilter reqFilter, int start, int nbRequested) {
 316                 super(dataType, TmfTimeRange.ETERNITY, start, nbRequested,
 317                         TmfEventRequest.ExecutionType.FOREGROUND);
 318                 requestFilter = reqFilter;
 319                 requestRank = start;
 320                 requestIndex = index;
 321             }
 322
 323             @Override
 324             public void handleData(ITmfEvent event) {
 325                 super.handleData(event);
 326                 if (isCancelled()) {
 327                     return;
 328                 }
 329                 if (requestRank >= rank) {
 330                     cancel();
 331                     return;
 332                 }
 333                 requestRank++;
 334                 if (requestFilter.matches(event)) {
 335                     requestIndex++;
 336                 }
 337             }
 338
 339             public int getFilteredIndex() {
 340                 return requestIndex;
 341             }
 342         }
 343
 344         request = new DataRequest(ITmfEvent.class, filter, startRank, ITmfEventRequest.ALL_DATA);
 345         ((ITmfEventProvider) fTrace).sendRequest(request);
 346         try {
 347             request.waitForCompletion();
 348             return ((DataRequest) request).getFilteredIndex();
 349         } catch (InterruptedException e) {
 350             Activator.getDefault().logError("Filter request interrupted!", e); //$NON-NLS-1$
 351         }
 352         return 0;
 353     }
 354
 355     // ------------------------------------------------------------------------
 356     // Event cache population
 357     // ------------------------------------------------------------------------
 358
 359     // The event fetching job
 360     private Job job;
 361     private synchronized void populateCache(final int index) {
 362
 363         /* Check if the current job will fetch the requested event:
 364          * 1. The job must exist
 365          * 2. It must be running (i.e. not completed)
 366          * 3. The requested index must be within the cache range
 367          *
 368          * If the job meets these conditions, we simply exit.
 369          * Otherwise, we create a new job but we might have to cancel
 370          * an existing job for an obsolete range.
 371          */
 372         if (job != null) {
 373             if (job.getState() != Job.NONE) {
 374                 if ((index >= fCacheStartIndex) && (index < (fCacheStartIndex + fCache.length))) {
 375                     return;
 376                 }
 377                 // The new index is out of the requested range
 378                 // Kill the job and start a new one
 379                 job.cancel();
 380             }
 381         }
 382
 383         // Populate the cache starting at the index that is one block less
 384         // of cache size than the requested index. The cache will hold two
 385         // consecutive blocks of cache size, centered on the requested index.
 386         fCacheStartIndex = Math.max(0, index - fCacheSize);
 387         fCacheEndIndex   = fCacheStartIndex;
 388
 389         job = new Job("Fetching Events") { //$NON-NLS-1$
 390             private int startIndex = fCacheStartIndex;
 391             private int skipCount = 0;
 392             @Override
 393             protected IStatus run(final IProgressMonitor monitor) {
 394
 395                 int nbRequested;
 396                 if (fFilter == null) {
 397                     nbRequested = fCache.length;
 398                 } else {
 399                     nbRequested = ITmfEventRequest.ALL_DATA;
 400                     int i = startIndex / fCacheSize;
 401                     if (i < fFilterIndex.size()) {
 402                         skipCount = startIndex - (i * fCacheSize);
 403                         startIndex = fFilterIndex.get(i);
 404                     }
 405                 }
 406
 407                 TmfEventRequest request = new TmfEventRequest(ITmfEvent.class,
 408                         TmfTimeRange.ETERNITY,
 409                         startIndex,
 410                         nbRequested,
 411                         TmfEventRequest.ExecutionType.FOREGROUND) {
 412                     private int count = 0;
 413                     private long rank = startIndex;
 414                     @Override
 415                     public void handleData(ITmfEvent event) {
 416                         // If the job is canceled, cancel the request so waitForCompletion() will unlock
 417                         if (monitor.isCanceled()) {
 418                             cancel();
 419                             return;
 420                         }
 421                         super.handleData(event);
 422                         if (((fFilter == null) || fFilter.matches(event)) && (skipCount-- <= 0)) {
 423                             synchronized (TmfEventsCache.this) {
 424                                 if (monitor.isCanceled()) {
 425                                     return;
 426                                 }
 427                                 fCache[count] = new CachedEvent(event, rank);
 428                                 count++;
 429                                 fCacheEndIndex++;
 430                             }
 431                             if (fFilter != null) {
 432                                 fTable.cacheUpdated(false);
 433                             }
 434                         } else if (((fFilter != null) && !fFilter.matches(event)) && (skipCount <= 0)) { // TODO fix duplicated call to matches()
 435                             if ((count > 0) && (fFilter instanceof TmfCollapseFilter)) {
 436                                 fCache[count - 1].repeatCount++;
 437                             }
 438                         }
 439                         if (count >= fCache.length) {
 440                             cancel();
 441                         } else if ((fFilter != null) && (count >= (fTable.getTable().getItemCount() - 3))) { // -1 for header row, -2 for top and bottom filter status rows
 442                             cancel();
 443                         }
 444                         rank++;
 445                     }
 446                 };
 447
 448                 ((ITmfEventProvider) fTrace).sendRequest(request);
 449                 try {
 450                     request.waitForCompletion();
 451                 } catch (InterruptedException e) {
 452                     Activator.getDefault().logError("Wait for completion interrupted for populateCache ", e); //$NON-NLS-1$
 453                 }
 454
 455                 fTable.cacheUpdated(true);
 456
 457                 // Flag the UI thread that the cache is ready
 458                 if (monitor.isCanceled()) {
 459                     return Status.CANCEL_STATUS;
 460                 }
 461                 return Status.OK_STATUS;
 462             }
 463         };
 464         //job.setSystem(true);
 465         job.setPriority(Job.SHORT);
 466         job.schedule();
 467     }
 468
 469 }