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

   1 /*******************************************************************************
   2  * Copyright (c) 2009, 2014 Ericsson, École Polytechnique de Montréal
   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  *   Francois Chouinard - Updated as per TMF Trace Model 1.0
  12  *   Geneviève Bastien  - Added timestamp transforms and timestamp
  13  *                        creation functions
  14  *   Patrick Tasse - Add support for folder elements
  15  *******************************************************************************/
  16
  17 package org.eclipse.linuxtools.tmf.core.trace;
  18
  19 import org.eclipse.core.resources.IProject;
  20 import org.eclipse.core.resources.IResource;
  21 import org.eclipse.core.runtime.IStatus;
  22 import org.eclipse.jdt.annotation.NonNull;
  23 import org.eclipse.jdt.annotation.Nullable;
  24 import org.eclipse.linuxtools.tmf.core.analysis.IAnalysisModule;
  25 import org.eclipse.linuxtools.tmf.core.component.ITmfEventProvider;
  26 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
  27 import org.eclipse.linuxtools.tmf.core.exceptions.TmfTraceException;
  28 import org.eclipse.linuxtools.tmf.core.synchronization.ITmfTimestampTransform;
  29 import org.eclipse.linuxtools.tmf.core.timestamp.ITmfTimestamp;
  30 import org.eclipse.linuxtools.tmf.core.timestamp.TmfTimeRange;
  31 import org.eclipse.linuxtools.tmf.core.trace.indexer.ITmfTraceIndexer;
  32 import org.eclipse.linuxtools.tmf.core.trace.location.ITmfLocation;
  33
  34 /**
  35  * The event stream structure in TMF. In its basic form, a trace has:
  36  * <ul>
  37  * <li> an associated Eclipse resource
  38  * <li> a path to its location on the file system
  39  * <li> the type of the events it contains
  40  * <li> the number of events it contains
  41  * <li> the time range (span) of the events it contains
  42  * </ul>
  43  * Concrete ITmfTrace classes have to provide a parameter-less constructor and
  44  * an initialization method (<i>initTrace</i>) if they are to be opened from the
  45  * Project View. Also, a validation method (<i>validate</i>) has to be provided
  46  * to ensure that the trace is of the correct type.
  47  * <p>
  48  * A trace can be accessed simultaneously from multiple threads by various
  49  * application components. To avoid obvious multi-threading issues, the trace
  50  * uses an ITmfContext as a synchronization aid for its read operations.
  51  * <p>
  52  * A proper ITmfContext can be obtained by performing a seek operation on the
  53  * trace. Seek operations can be performed for a particular event (by rank or
  54  * timestamp) or for a plain trace location.
  55  * <p>
  56  * <b>Example 1</b>: Process a whole trace
  57  * <pre>
  58  * ITmfContext context = trace.seekEvent(0);
  59  * ITmfEvent event = trace.getNext(context);
  60  * while (event != null) {
  61  *     processEvent(event);
  62  *     event = trace.getNext(context);
  63  * }
  64  * </pre>
  65  * <b>Example 2</b>: Process 50 events starting from the 1000th event
  66  * <pre>
  67  * int nbEventsRead = 0;
  68  * ITmfContext context = trace.seekEvent(1000);
  69  * ITmfEvent event = trace.getNext(context);
  70  * while (event != null && nbEventsRead < 50) {
  71  *     nbEventsRead++;
  72  *     processEvent(event);
  73  *     event = trace.getNext(context);
  74  * }
  75  * </pre>
  76  * <b>Example 3</b>: Process the events between 2 timestamps (inclusive)
  77  * <pre>
  78  * ITmfTimestamp startTime = ...;
  79  * ITmfTimestamp endTime = ...;
  80  * ITmfContext context = trace.seekEvent(startTime);
  81  * ITmfEvent event = trace.getNext(context);
  82  * while (event != null && event.getTimestamp().compareTo(endTime) <= 0) {
  83  *     processEvent(event);
  84  *     event = trace.getNext(context);
  85  * }
  86  * </pre>
  87  *
  88  * A trace is also an event provider so it can process event requests
  89  * asynchronously (and coalesce compatible, concurrent requests).
  90  * <p>
  91  *
  92  * <b>Example 4</b>: Process a whole trace (see ITmfEventRequest for
  93  * variants)
  94  * <pre>
  95  * ITmfRequest request = new TmfEventRequest&lt;MyEventType&gt;(MyEventType.class) {
  96  *     &#064;Override
  97  *     public void handleData(MyEventType event) {
  98  *         super.handleData(event);
  99  *         processEvent(event);
 100  *     }
 101  *
 102  *     &#064;Override
 103  *     public void handleCompleted() {
 104  *         finish();
 105  *         super.handleCompleted();
 106  *     }
 107  * };
 108  *
 109  * fTrace.handleRequest(request);
 110  * if (youWant) {
 111  *     request.waitForCompletion();
 112  * }
 113  * </pre>
 114  *
 115  * @version 1.0
 116  * @author Francois Chouinard
 117  *
 118  * @see ITmfContext
 119  * @see ITmfEvent
 120  * @see ITmfTraceIndexer
 121  * @see ITmfEventParser
 122  */
 123 public interface ITmfTrace extends ITmfEventProvider {
 124
 125     // ------------------------------------------------------------------------
 126     // Constants
 127     // ------------------------------------------------------------------------
 128
 129     /**
 130      * The default trace cache size
 131      */
 132     public static final int DEFAULT_TRACE_CACHE_SIZE = 1000;
 133
 134     // ------------------------------------------------------------------------
 135     // Initializers
 136     // ------------------------------------------------------------------------
 137
 138     /**
 139      * Initialize a newly instantiated "empty" trace object. This is used to
 140      * properly parameterize an ITmfTrace instantiated with its parameterless
 141      * constructor.
 142      * <p>
 143      * Typically, the parameterless constructor will provide the block size and
 144      * its associated parser and indexer.
 145      *
 146      * @param resource
 147      *            the trace resource
 148      * @param path
 149      *            the trace path
 150      * @param type
 151      *            the trace event type
 152      * @throws TmfTraceException
 153      *             If we couldn't open the trace
 154      */
 155     void initTrace(IResource resource, String path, Class<? extends ITmfEvent> type) throws TmfTraceException;
 156
 157     /**
 158      * Initialize a newly instantiated "empty" trace object. This is used to
 159      * properly parameterize an ITmfTrace instantiated with its parameterless
 160      * constructor.
 161      * <p>
 162      * Typically, the parameterless constructor will provide the block size and
 163      * its associated parser and indexer.
 164      *
 165      * @param resource
 166      *            the trace resource
 167      * @param path
 168      *            the trace path
 169      * @param type
 170      *            the trace event type
 171      * @param name
 172      *            the trace name
 173      * @throws TmfTraceException
 174      *             If we couldn't open the trace
 175      */
 176     void initTrace(IResource resource, String path, Class<? extends ITmfEvent> type, String name) throws TmfTraceException;
 177
 178     /**
 179      * Validate that the trace is of the correct type. The implementation should
 180      * return a TraceValidationStatus to indicate success with a certain level
 181      * of confidence.
 182      *
 183      * @param project
 184      *            the eclipse project
 185      * @param path
 186      *            the trace path
 187      *
 188      * @return an IStatus object with validation result. Use severity OK to
 189      *         indicate success.
 190      * @see {@link TraceValidationStatus}
 191      * @since 2.0
 192      */
 193     IStatus validate(IProject project, String path);
 194
 195     // ------------------------------------------------------------------------
 196     // Basic getters
 197     // ------------------------------------------------------------------------
 198
 199     /**
 200      * @return the trace event type
 201      */
 202     Class<? extends ITmfEvent> getEventType();
 203
 204     /**
 205      * @return the associated trace resource
 206      */
 207     IResource getResource();
 208
 209     /**
 210      * @return the trace path
 211      */
 212     String getPath();
 213
 214     /**
 215      * @return the trace cache size
 216      */
 217     int getCacheSize();
 218
 219     /**
 220      * Index the trace. Depending on the trace type, this could be done at the
 221      * constructor or initTrace phase too, so this could be implemented as a
 222      * no-op.
 223      *
 224      * @param waitForCompletion
 225      *            Should we block the caller until indexing is finished, or not.
 226      * @since 2.0
 227      */
 228     void indexTrace(boolean waitForCompletion);
 229
 230     // ------------------------------------------------------------------------
 231     // Analysis getters
 232     // ------------------------------------------------------------------------
 233
 234     /**
 235      * Returns an analysis module with the given ID.
 236      *
 237      * @param id
 238      *            The analysis module ID
 239      * @return The {@link IAnalysisModule} object, or null if an analysis with
 240      *         the given ID does no exist.
 241      * @since 3.0
 242      */
 243     @Nullable
 244     IAnalysisModule getAnalysisModule(String id);
 245
 246     /**
 247      * Get a list of all analysis modules currently available for this trace.
 248      *
 249      * @return An iterable view of the analysis modules
 250      * @since 3.0
 251      */
 252     @NonNull
 253     Iterable<IAnalysisModule> getAnalysisModules();
 254
 255     /**
 256      * Get an analysis module belonging to this trace, with the specified ID and
 257      * class.
 258      *
 259      * @param moduleClass
 260      *            Returned modules must extend this class
 261      * @param id
 262      *            The ID of the analysis module
 263      * @return The analysis module with specified class and ID, or null if no
 264      *         such module exists.
 265      * @since 3.0
 266      */
 267     @Nullable
 268     <T extends IAnalysisModule> T getAnalysisModuleOfClass(Class<T> moduleClass, String id);
 269
 270     /**
 271      * Return the analysis modules that are of a given class. Module are already
 272      * casted to the requested class.
 273      *
 274      * @param moduleClass
 275      *            Returned modules must extend this class
 276      * @return List of modules of class moduleClass
 277      * @since 3.0
 278      */
 279     @NonNull
 280     <T> Iterable<T> getAnalysisModulesOfClass(Class<T> moduleClass);
 281
 282     // ------------------------------------------------------------------------
 283     // Trace characteristics getters
 284     // ------------------------------------------------------------------------
 285
 286     /**
 287      * @return the number of events in the trace
 288      */
 289     long getNbEvents();
 290
 291     /**
 292      * @return the trace time range
 293      * @since 2.0
 294      */
 295     TmfTimeRange getTimeRange();
 296
 297     /**
 298      * @return the timestamp of the first trace event
 299      * @since 2.0
 300      */
 301     ITmfTimestamp getStartTime();
 302
 303     /**
 304      * @return the timestamp of the last trace event
 305      * @since 2.0
 306      */
 307     ITmfTimestamp getEndTime();
 308
 309     /**
 310      * @return the streaming interval in ms (0 if not a streaming trace)
 311      */
 312     long getStreamingInterval();
 313
 314     // ------------------------------------------------------------------------
 315     // Trace positioning getters
 316     // ------------------------------------------------------------------------
 317
 318     /**
 319      * @return the current trace location
 320      * @since 3.0
 321      */
 322     ITmfLocation getCurrentLocation();
 323
 324     /**
 325      * Returns the ratio (proportion) corresponding to the specified location.
 326      *
 327      * @param location
 328      *            a trace specific location
 329      * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
 330      * @since 3.0
 331      */
 332     double getLocationRatio(ITmfLocation location);
 333
 334     // ------------------------------------------------------------------------
 335     // SeekEvent operations (returning a trace context)
 336     // ------------------------------------------------------------------------
 337
 338     /**
 339      * Position the trace at the specified (trace specific) location.
 340      * <p>
 341      * A null location is interpreted as seeking for the first event of the
 342      * trace.
 343      * <p>
 344      * If not null, the location requested must be valid otherwise the returned
 345      * context is undefined (up to the implementation to recover if possible).
 346      * <p>
 347      *
 348      * @param location
 349      *            the trace specific location
 350      * @return a context which can later be used to read the corresponding event
 351      * @since 3.0
 352      */
 353     ITmfContext seekEvent(ITmfLocation location);
 354
 355     /**
 356      * Position the trace at the 'rank'th event in the trace.
 357      * <p>
 358      * A rank <= 0 is interpreted as seeking for the first event of the trace.
 359      * <p>
 360      * If the requested rank is beyond the last trace event, the context
 361      * returned will yield a null event if used in a subsequent read.
 362      *
 363      * @param rank
 364      *            the event rank
 365      * @return a context which can later be used to read the corresponding event
 366      */
 367     ITmfContext seekEvent(long rank);
 368
 369     /**
 370      * Position the trace at the first event with the specified timestamp. If
 371      * there is no event with the requested timestamp, a context pointing to the
 372      * next chronological event is returned.
 373      * <p>
 374      * A null timestamp is interpreted as seeking for the first event of the
 375      * trace.
 376      * <p>
 377      * If the requested timestamp is beyond the last trace event, the context
 378      * returned will yield a null event if used in a subsequent read.
 379      *
 380      * @param timestamp
 381      *            the timestamp of desired event
 382      * @return a context which can later be used to read the corresponding event
 383      * @since 2.0
 384      */
 385     ITmfContext seekEvent(ITmfTimestamp timestamp);
 386
 387     /**
 388      * Position the trace at the event located at the specified ratio in the
 389      * trace file.
 390      * <p>
 391      * The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
 392      * voluntarily vague. Typically, it would refer to the event proportional
 393      * rank (arguably more intuitive) or timestamp in the trace file.
 394      *
 395      * @param ratio
 396      *            the proportional 'rank' in the trace
 397      * @return a context which can later be used to read the corresponding event
 398      */
 399     ITmfContext seekEvent(double ratio);
 400
 401     /**
 402      * Returns the initial range offset
 403      *
 404      * @return the initial range offset
 405      * @since 2.0
 406      */
 407     ITmfTimestamp getInitialRangeOffset();
 408
 409     /**
 410      * Returns the ID of the host this trace is from. The host ID is not
 411      * necessarily the hostname, but should be a unique identifier for the
 412      * machine on which the trace was taken. It can be used to determine if two
 413      * traces were taken on the exact same machine (timestamp are already
 414      * synchronized, resources with same id are the same if taken at the same
 415      * time, etc).
 416      *
 417      * @return The host id of this trace
 418      * @since 3.0
 419      */
 420     String getHostId();
 421
 422     // ------------------------------------------------------------------------
 423     // Timestamp transformation functions
 424     // ------------------------------------------------------------------------
 425
 426     /**
 427      * Returns the timestamp transformation for this trace
 428      *
 429      * @return the timestamp transform
 430      * @since 3.0
 431      */
 432     ITmfTimestampTransform getTimestampTransform();
 433
 434     /**
 435      * Sets the trace's timestamp transform
 436      *
 437      * @param tt
 438      *            The timestamp transform for all timestamps of this trace
 439      * @since 3.0
 440      */
 441     void setTimestampTransform(final ITmfTimestampTransform tt);
 442
 443     /**
 444      * Creates a timestamp for this trace, using the transformation formula
 445      *
 446      * @param ts
 447      *            The time in nanoseconds with which to create the timestamp
 448      * @return The new timestamp
 449      * @since 3.0
 450      */
 451     ITmfTimestamp createTimestamp(long ts);
 452
 453 }