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

   1 /*******************************************************************************
   2  * Copyright (c) 2009, 2013 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  *******************************************************************************/
  15
  16 package org.eclipse.linuxtools.tmf.core.trace;
  17
  18 import java.util.Collections;
  19 import java.util.List;
  20 import java.util.Map;
  21
  22 import org.eclipse.core.resources.IProject;
  23 import org.eclipse.core.resources.IResource;
  24 import org.eclipse.core.runtime.IStatus;
  25 import org.eclipse.linuxtools.tmf.core.analysis.IAnalysisModule;
  26 import org.eclipse.linuxtools.tmf.core.component.ITmfDataProvider;
  27 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
  28 import org.eclipse.linuxtools.tmf.core.exceptions.TmfTraceException;
  29 import org.eclipse.linuxtools.tmf.core.statesystem.ITmfStateSystem;
  30 import org.eclipse.linuxtools.tmf.core.statistics.ITmfStatistics;
  31 import org.eclipse.linuxtools.tmf.core.synchronization.ITmfTimestampTransform;
  32 import org.eclipse.linuxtools.tmf.core.timestamp.ITmfTimestamp;
  33 import org.eclipse.linuxtools.tmf.core.timestamp.TmfTimeRange;
  34 import org.eclipse.linuxtools.tmf.core.trace.indexer.ITmfTraceIndexer;
  35 import org.eclipse.linuxtools.tmf.core.trace.location.ITmfLocation;
  36
  37 /**
  38  * The event stream structure in TMF. In its basic form, a trace has:
  39  * <ul>
  40  * <li> an associated Eclipse resource
  41  * <li> a path to its location on the file system
  42  * <li> the type of the events it contains
  43  * <li> the number of events it contains
  44  * <li> the time range (span) of the events it contains
  45  * </ul>
  46  * Concrete ITmfTrace classes have to provide a parameter-less constructor and
  47  * an initialization method (<i>initTrace</i>) if they are to be opened from the
  48  * Project View. Also, a validation method (<i>validate</i>) has to be provided
  49  * to ensure that the trace is of the correct type.
  50  * <p>
  51  * A trace can be accessed simultaneously from multiple threads by various
  52  * application components. To avoid obvious multi-threading issues, the trace
  53  * uses an ITmfContext as a synchronization aid for its read operations.
  54  * <p>
  55  * A proper ITmfContext can be obtained by performing a seek operation on the
  56  * trace. Seek operations can be performed for a particular event (by rank or
  57  * timestamp) or for a plain trace location.
  58  * <p>
  59  * <b>Example 1</b>: Process a whole trace
  60  * <pre>
  61  * ITmfContext context = trace.seekEvent(0);
  62  * ITmfEvent event = trace.getNext(context);
  63  * while (event != null) {
  64  *     processEvent(event);
  65  *     event = trace.getNext(context);
  66  * }
  67  * </pre>
  68  * <b>Example 2</b>: Process 50 events starting from the 1000th event
  69  * <pre>
  70  * int nbEventsRead = 0;
  71  * ITmfContext context = trace.seekEvent(1000);
  72  * ITmfEvent event = trace.getNext(context);
  73  * while (event != null && nbEventsRead < 50) {
  74  *     nbEventsRead++;
  75  *     processEvent(event);
  76  *     event = trace.getNext(context);
  77  * }
  78  * </pre>
  79  * <b>Example 3</b>: Process the events between 2 timestamps (inclusive)
  80  * <pre>
  81  * ITmfTimestamp startTime = ...;
  82  * ITmfTimestamp endTime = ...;
  83  * ITmfContext context = trace.seekEvent(startTime);
  84  * ITmfEvent event = trace.getNext(context);
  85  * while (event != null && event.getTimestamp().compareTo(endTime) <= 0) {
  86  *     processEvent(event);
  87  *     event = trace.getNext(context);
  88  * }
  89  * </pre>
  90  *
  91  * A trace is also an event provider so it can process event requests
  92  * asynchronously (and coalesce compatible, concurrent requests).
  93  * <p>
  94  *
  95  * <b>Example 4</b>: Process a whole trace (see ITmfEventRequest for
  96  * variants)
  97  * <pre>
  98  * ITmfRequest request = new TmfEventRequest&lt;MyEventType&gt;(MyEventType.class) {
  99  *     &#064;Override
 100  *     public void handleData(MyEventType event) {
 101  *         super.handleData(event);
 102  *         processEvent(event);
 103  *     }
 104  *
 105  *     &#064;Override
 106  *     public void handleCompleted() {
 107  *         finish();
 108  *         super.handleCompleted();
 109  *     }
 110  * };
 111  *
 112  * fTrace.handleRequest(request);
 113  * if (youWant) {
 114  *     request.waitForCompletion();
 115  * }
 116  * </pre>
 117  *
 118  * @version 1.0
 119  * @author Francois Chouinard
 120  *
 121  * @see ITmfContext
 122  * @see ITmfEvent
 123  * @see ITmfTraceIndexer
 124  * @see ITmfEventParser
 125  */
 126 public interface ITmfTrace extends ITmfDataProvider {
 127
 128     // ------------------------------------------------------------------------
 129     // Constants
 130     // ------------------------------------------------------------------------
 131
 132     /**
 133      * The default trace cache size
 134      */
 135     public static final int DEFAULT_TRACE_CACHE_SIZE = 1000;
 136
 137     // ------------------------------------------------------------------------
 138     // Initializers
 139     // ------------------------------------------------------------------------
 140
 141     /**
 142      * Initialize a newly instantiated "empty" trace object. This is used to
 143      * properly parameterize an ITmfTrace instantiated with its parameterless
 144      * constructor.
 145      * <p>
 146      * Typically, the parameterless constructor will provide the block size and
 147      * its associated parser and indexer.
 148      *
 149      * @param resource
 150      *            the trace resource
 151      * @param path
 152      *            the trace path
 153      * @param type
 154      *            the trace event type
 155      * @throws TmfTraceException
 156      *             If we couldn't open the trace
 157      */
 158     void initTrace(IResource resource, String path, Class<? extends ITmfEvent> type) throws TmfTraceException;
 159
 160     /**
 161      * Validate that the trace is of the correct type.
 162      *
 163      * @param project
 164      *            the eclipse project
 165      * @param path
 166      *            the trace path
 167      * @return an IStatus object with validation result. Use severity OK to
 168      *         indicate success.
 169      * @since 2.0
 170      */
 171     IStatus validate(IProject project, String path);
 172
 173     // ------------------------------------------------------------------------
 174     // Basic getters
 175     // ------------------------------------------------------------------------
 176
 177     /**
 178      * @return the trace event type
 179      */
 180     Class<? extends ITmfEvent> getEventType();
 181
 182     /**
 183      * @return the associated trace resource
 184      */
 185     IResource getResource();
 186
 187     /**
 188      * @return the trace path
 189      */
 190     String getPath();
 191
 192     /**
 193      * @return the trace cache size
 194      */
 195     int getCacheSize();
 196
 197     /**
 198      * @return The statistics provider for this trace
 199      * @since 2.0
 200      */
 201     ITmfStatistics getStatistics();
 202
 203     /**
 204      * Return the map of state systems associated with this trace.
 205      *
 206      * This view should be read-only (implementations should use
 207      * {@link Collections#unmodifiableMap}).
 208      *
 209      * @return The map of state systems
 210      * @since 2.0
 211      */
 212     Map<String, ITmfStateSystem> getStateSystems();
 213
 214     /**
 215      * If a state system is not build by the trace itself, it's possible to
 216      * register it if it comes from another source. It will then be accessible
 217      * with {@link #getStateSystems} normally.
 218      *
 219      * @param id
 220      *            The unique ID to assign to this state system. In case of
 221      *            conflicting ID's, the new one will overwrite the previous one
 222      *            (default Map behavior).
 223      * @param ss
 224      *            The already-built state system
 225      * @since 2.0
 226      */
 227     void registerStateSystem(String id, ITmfStateSystem ss);
 228
 229     /**
 230      * Index the trace. Depending on the trace type, this could be done at the
 231      * constructor or initTrace phase too, so this could be implemented as a
 232      * no-op.
 233      *
 234      * @param waitForCompletion
 235      *            Should we block the caller until indexing is finished, or not.
 236      * @since 2.0
 237      */
 238     void indexTrace(boolean waitForCompletion);
 239
 240     /**
 241      * Returns an analysis module with the given id
 242      *
 243      * @param analysisId
 244      *            The analysis module id
 245      * @return The {@link IAnalysisModule} object
 246      */
 247     IAnalysisModule getAnalysisModule(String analysisId);
 248
 249     /**
 250      * Return a list of analysis modules that are of a given class
 251      *
 252      * @param moduleclass
 253      *            Class returned module must extend
 254      * @return List of {@link IAnalysisModule} of class moduleclass
 255      */
 256     List<IAnalysisModule> getAnalysisModules(Class<? extends IAnalysisModule> moduleclass);
 257
 258     /**
 259      * Returns a map of analysis modules applicable to this trace. The key is
 260      * the analysis id.
 261      *
 262      * This view should be read-only (implementations should use
 263      * {@link Collections#unmodifiableMap}).
 264      *
 265      * @return The map of analysis modules
 266      */
 267     Map<String, IAnalysisModule> getAnalysisModules();
 268
 269     // ------------------------------------------------------------------------
 270     // Trace characteristics getters
 271     // ------------------------------------------------------------------------
 272
 273     /**
 274      * @return the number of events in the trace
 275      */
 276     long getNbEvents();
 277
 278     /**
 279      * @return the trace time range
 280      * @since 2.0
 281      */
 282     TmfTimeRange getTimeRange();
 283
 284     /**
 285      * @return the timestamp of the first trace event
 286      * @since 2.0
 287      */
 288     ITmfTimestamp getStartTime();
 289
 290     /**
 291      * @return the timestamp of the last trace event
 292      * @since 2.0
 293      */
 294     ITmfTimestamp getEndTime();
 295
 296     /**
 297      * @return the streaming interval in ms (0 if not a streaming trace)
 298      */
 299     long getStreamingInterval();
 300
 301     // ------------------------------------------------------------------------
 302     // Trace positioning getters
 303     // ------------------------------------------------------------------------
 304
 305     /**
 306      * @return the current trace location
 307      * @since 3.0
 308      */
 309     ITmfLocation getCurrentLocation();
 310
 311     /**
 312      * Returns the ratio (proportion) corresponding to the specified location.
 313      *
 314      * @param location
 315      *            a trace specific location
 316      * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
 317      * @since 3.0
 318      */
 319     double getLocationRatio(ITmfLocation location);
 320
 321     // ------------------------------------------------------------------------
 322     // SeekEvent operations (returning a trace context)
 323     // ------------------------------------------------------------------------
 324
 325     /**
 326      * Position the trace at the specified (trace specific) location.
 327      * <p>
 328      * A null location is interpreted as seeking for the first event of the
 329      * trace.
 330      * <p>
 331      * If not null, the location requested must be valid otherwise the returned
 332      * context is undefined (up to the implementation to recover if possible).
 333      * <p>
 334      *
 335      * @param location
 336      *            the trace specific location
 337      * @return a context which can later be used to read the corresponding event
 338      * @since 3.0
 339      */
 340     ITmfContext seekEvent(ITmfLocation location);
 341
 342     /**
 343      * Position the trace at the 'rank'th event in the trace.
 344      * <p>
 345      * A rank <= 0 is interpreted as seeking for the first event of the trace.
 346      * <p>
 347      * If the requested rank is beyond the last trace event, the context
 348      * returned will yield a null event if used in a subsequent read.
 349      *
 350      * @param rank
 351      *            the event rank
 352      * @return a context which can later be used to read the corresponding event
 353      */
 354     ITmfContext seekEvent(long rank);
 355
 356     /**
 357      * Position the trace at the first event with the specified timestamp. If
 358      * there is no event with the requested timestamp, a context pointing to the
 359      * next chronological event is returned.
 360      * <p>
 361      * A null timestamp is interpreted as seeking for the first event of the
 362      * trace.
 363      * <p>
 364      * If the requested timestamp is beyond the last trace event, the context
 365      * returned will yield a null event if used in a subsequent read.
 366      *
 367      * @param timestamp
 368      *            the timestamp of desired event
 369      * @return a context which can later be used to read the corresponding event
 370      * @since 2.0
 371      */
 372     ITmfContext seekEvent(ITmfTimestamp timestamp);
 373
 374     /**
 375      * Position the trace at the event located at the specified ratio in the
 376      * trace file.
 377      * <p>
 378      * The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
 379      * voluntarily vague. Typically, it would refer to the event proportional
 380      * rank (arguably more intuitive) or timestamp in the trace file.
 381      *
 382      * @param ratio
 383      *            the proportional 'rank' in the trace
 384      * @return a context which can later be used to read the corresponding event
 385      */
 386     ITmfContext seekEvent(double ratio);
 387
 388     /**
 389      * Returns the initial range offset
 390      *
 391      * @return the initial range offset
 392      * @since 2.0
 393      */
 394     ITmfTimestamp getInitialRangeOffset();
 395
 396     /**
 397      * Returns the ID of the host this trace is from. The host ID is not
 398      * necessarily the hostname, but should be a unique identifier for the
 399      * machine on which the trace was taken. It can be used to determine if two
 400      * traces were taken on the exact same machine (timestamp are already
 401      * synchronized, resources with same id are the same if taken at the same
 402      * time, etc).
 403      *
 404      * @return The host id of this trace
 405      * @since 3.0
 406      */
 407     String getHostId();
 408
 409     // ------------------------------------------------------------------------
 410     // Timestamp transformation functions
 411     // ------------------------------------------------------------------------
 412
 413     /**
 414      * Returns the timestamp transformation for this trace
 415      *
 416      * @return the timestamp transform
 417      * @since 3.0
 418      */
 419     ITmfTimestampTransform getTimestampTransform();
 420
 421     /**
 422      * Sets the trace's timestamp transform
 423      *
 424      * @param tt
 425      *            The timestamp transform for all timestamps of this trace
 426      * @since 3.0
 427      */
 428     void setTimestampTransform(final ITmfTimestampTransform tt);
 429
 430     /**
 431      * Creates a timestamp for this trace, using the transformation formula
 432      *
 433      * @param ts
 434      *            The time in long with which to create the timestamp
 435      * @return The new timestamp
 436      * @since 3.0
 437      */
 438     ITmfTimestamp createTimestamp(long ts);
 439
 440 }