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