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.Map;
  20
  21 import org.eclipse.core.resources.IProject;
  22 import org.eclipse.core.resources.IResource;
  23 import org.eclipse.core.runtime.IStatus;
  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.statesystem.ITmfStateSystem;
  29 import org.eclipse.linuxtools.tmf.core.statesystem.ITmfAnalysisModuleWithStateSystems;
  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 ITmfEventProvider {
 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      * @deprecated State systems now should be provided by analysis and use
 212      *             {@link ITmfAnalysisModuleWithStateSystems} and retrieve the modules
 213      *             with {@link TmfTrace#getAnalysisModules(Class)} with Class
 214      *             being TmfStateSystemAnalysisModule.class
 215      */
 216     @Deprecated
 217     Map<String, ITmfStateSystem> getStateSystems();
 218
 219     /**
 220      * If a state system is not build by the trace itself, it's possible to
 221      * register it if it comes from another source. It will then be accessible
 222      * with {@link #getStateSystems} normally.
 223      *
 224      * @param id
 225      *            The unique ID to assign to this state system. In case of
 226      *            conflicting ID's, the new one will overwrite the previous one
 227      *            (default Map behavior).
 228      * @param ss
 229      *            The already-built state system
 230      * @since 2.0
 231      * @deprecated State systems now should be provided by analysis and use
 232      *             {@link ITmfAnalysisModuleWithStateSystems}
 233      */
 234     @Deprecated
 235     void registerStateSystem(String id, ITmfStateSystem ss);
 236
 237     /**
 238      * Index the trace. Depending on the trace type, this could be done at the
 239      * constructor or initTrace phase too, so this could be implemented as a
 240      * no-op.
 241      *
 242      * @param waitForCompletion
 243      *            Should we block the caller until indexing is finished, or not.
 244      * @since 2.0
 245      */
 246     void indexTrace(boolean waitForCompletion);
 247
 248     /**
 249      * Returns an analysis module with the given id
 250      *
 251      * @param analysisId
 252      *            The analysis module id
 253      * @return The {@link IAnalysisModule} object
 254      * @since 3.0
 255      */
 256     IAnalysisModule getAnalysisModule(String analysisId);
 257
 258     /**
 259      * Return a map of analysis modules that are of a given class. Module are
 260      * already casted to the requested class
 261      *
 262      * @param moduleclass
 263      *            Class returned module must extend
 264      * @return List of modules of class moduleclass
 265      * @since 3.0
 266      */
 267     <T> Map<String, T> getAnalysisModules(Class<T> moduleclass);
 268
 269     /**
 270      * Returns a map of analysis modules applicable to this trace. The key is
 271      * the analysis id.
 272      *
 273      * This view should be read-only (implementations should use
 274      * {@link Collections#unmodifiableMap}).
 275      *
 276      * @return The map of analysis modules
 277      * @since 3.0
 278      */
 279     Map<String, IAnalysisModule> getAnalysisModules();
 280
 281     // ------------------------------------------------------------------------
 282     // Trace characteristics getters
 283     // ------------------------------------------------------------------------
 284
 285     /**
 286      * @return the number of events in the trace
 287      */
 288     long getNbEvents();
 289
 290     /**
 291      * @return the trace time range
 292      * @since 2.0
 293      */
 294     TmfTimeRange getTimeRange();
 295
 296     /**
 297      * @return the timestamp of the first trace event
 298      * @since 2.0
 299      */
 300     ITmfTimestamp getStartTime();
 301
 302     /**
 303      * @return the timestamp of the last trace event
 304      * @since 2.0
 305      */
 306     ITmfTimestamp getEndTime();
 307
 308     /**
 309      * @return the streaming interval in ms (0 if not a streaming trace)
 310      */
 311     long getStreamingInterval();
 312
 313     // ------------------------------------------------------------------------
 314     // Trace positioning getters
 315     // ------------------------------------------------------------------------
 316
 317     /**
 318      * @return the current trace location
 319      * @since 3.0
 320      */
 321     ITmfLocation getCurrentLocation();
 322
 323     /**
 324      * Returns the ratio (proportion) corresponding to the specified location.
 325      *
 326      * @param location
 327      *            a trace specific location
 328      * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
 329      * @since 3.0
 330      */
 331     double getLocationRatio(ITmfLocation location);
 332
 333     // ------------------------------------------------------------------------
 334     // SeekEvent operations (returning a trace context)
 335     // ------------------------------------------------------------------------
 336
 337     /**
 338      * Position the trace at the specified (trace specific) location.
 339      * <p>
 340      * A null location is interpreted as seeking for the first event of the
 341      * trace.
 342      * <p>
 343      * If not null, the location requested must be valid otherwise the returned
 344      * context is undefined (up to the implementation to recover if possible).
 345      * <p>
 346      *
 347      * @param location
 348      *            the trace specific location
 349      * @return a context which can later be used to read the corresponding event
 350      * @since 3.0
 351      */
 352     ITmfContext seekEvent(ITmfLocation location);
 353
 354     /**
 355      * Position the trace at the 'rank'th event in the trace.
 356      * <p>
 357      * A rank <= 0 is interpreted as seeking for the first event of the trace.
 358      * <p>
 359      * If the requested rank is beyond the last trace event, the context
 360      * returned will yield a null event if used in a subsequent read.
 361      *
 362      * @param rank
 363      *            the event rank
 364      * @return a context which can later be used to read the corresponding event
 365      */
 366     ITmfContext seekEvent(long rank);
 367
 368     /**
 369      * Position the trace at the first event with the specified timestamp. If
 370      * there is no event with the requested timestamp, a context pointing to the
 371      * next chronological event is returned.
 372      * <p>
 373      * A null timestamp is interpreted as seeking for the first event of the
 374      * trace.
 375      * <p>
 376      * If the requested timestamp is beyond the last trace event, the context
 377      * returned will yield a null event if used in a subsequent read.
 378      *
 379      * @param timestamp
 380      *            the timestamp of desired event
 381      * @return a context which can later be used to read the corresponding event
 382      * @since 2.0
 383      */
 384     ITmfContext seekEvent(ITmfTimestamp timestamp);
 385
 386     /**
 387      * Position the trace at the event located at the specified ratio in the
 388      * trace file.
 389      * <p>
 390      * The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
 391      * voluntarily vague. Typically, it would refer to the event proportional
 392      * rank (arguably more intuitive) or timestamp in the trace file.
 393      *
 394      * @param ratio
 395      *            the proportional 'rank' in the trace
 396      * @return a context which can later be used to read the corresponding event
 397      */
 398     ITmfContext seekEvent(double ratio);
 399
 400     /**
 401      * Returns the initial range offset
 402      *
 403      * @return the initial range offset
 404      * @since 2.0
 405      */
 406     ITmfTimestamp getInitialRangeOffset();
 407
 408     /**
 409      * Returns the ID of the host this trace is from. The host ID is not
 410      * necessarily the hostname, but should be a unique identifier for the
 411      * machine on which the trace was taken. It can be used to determine if two
 412      * traces were taken on the exact same machine (timestamp are already
 413      * synchronized, resources with same id are the same if taken at the same
 414      * time, etc).
 415      *
 416      * @return The host id of this trace
 417      * @since 3.0
 418      */
 419     String getHostId();
 420
 421     // ------------------------------------------------------------------------
 422     // Timestamp transformation functions
 423     // ------------------------------------------------------------------------
 424
 425     /**
 426      * Returns the timestamp transformation for this trace
 427      *
 428      * @return the timestamp transform
 429      * @since 3.0
 430      */
 431     ITmfTimestampTransform getTimestampTransform();
 432
 433     /**
 434      * Sets the trace's timestamp transform
 435      *
 436      * @param tt
 437      *            The timestamp transform for all timestamps of this trace
 438      * @since 3.0
 439      */
 440     void setTimestampTransform(final ITmfTimestampTransform tt);
 441
 442     /**
 443      * Creates a timestamp for this trace, using the transformation formula
 444      *
 445      * @param ts
 446      *            The time in long with which to create the timestamp
 447      * @return The new timestamp
 448      * @since 3.0
 449      */
 450     ITmfTimestamp createTimestamp(long ts);
 451
 452 }