tmf/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      */
 199     IStatus validate(IProject project, String path);
 200
 201     // ------------------------------------------------------------------------
 202     // Basic getters
 203     // ------------------------------------------------------------------------
 204
 205     /**
 206      * @return the trace event type
 207      */
 208     Class<? extends ITmfEvent> getEventType();
 209
 210     /**
 211      * @return the associated trace resource
 212      */
 213     IResource getResource();
 214
 215     /**
 216      * Get the trace type id
 217      *
 218      * @return the trace type id
 219      */
 220     @Nullable String getTraceTypeId();
 221
 222     /**
 223      * @return the trace path
 224      */
 225     String getPath();
 226
 227     /**
 228      * @return the trace cache size
 229      */
 230     int getCacheSize();
 231
 232     /**
 233      * Index the trace. Depending on the trace type, this could be done at the
 234      * constructor or initTrace phase too, so this could be implemented as a
 235      * no-op.
 236      *
 237      * @param waitForCompletion
 238      *            Should we block the caller until indexing is finished, or not.
 239      */
 240     void indexTrace(boolean waitForCompletion);
 241
 242     // ------------------------------------------------------------------------
 243     // Analysis getters
 244     // ------------------------------------------------------------------------
 245
 246     /**
 247      * Returns an analysis module with the given ID.
 248      *
 249      * @param id
 250      *            The analysis module ID
 251      * @return The {@link IAnalysisModule} object, or null if an analysis with
 252      *         the given ID does no exist.
 253      */
 254     @Nullable IAnalysisModule getAnalysisModule(String id);
 255
 256     /**
 257      * Get a list of all analysis modules currently available for this trace.
 258      *
 259      * @return An iterable view of the analysis modules
 260      */
 261     @NonNull Iterable<IAnalysisModule> getAnalysisModules();
 262
 263     // ------------------------------------------------------------------------
 264     // Aspect getters
 265     // ------------------------------------------------------------------------
 266
 267     /**
 268      * Return the pre-defined set of event aspects exposed by this trace.
 269      *
 270      * It should not be null, but could be empty. You are suggested to use at
 271      * least the ones defined in {@link TmfTrace#BASE_ASPECTS}.
 272      *
 273      * @return The event aspects for this trace
 274      */
 275     @NonNull Iterable<ITmfEventAspect> getEventAspects();
 276
 277     // ------------------------------------------------------------------------
 278     // Trace characteristics getters
 279     // ------------------------------------------------------------------------
 280
 281     /**
 282      * @return the number of events in the trace
 283      */
 284     long getNbEvents();
 285
 286     /**
 287      * @return the trace time range
 288      */
 289     @NonNull TmfTimeRange getTimeRange();
 290
 291     /**
 292      * @return the timestamp of the first trace event
 293      */
 294     @NonNull ITmfTimestamp getStartTime();
 295
 296     /**
 297      * @return the timestamp of the last trace event
 298      */
 299     @NonNull ITmfTimestamp getEndTime();
 300
 301     /**
 302      * @return the streaming interval in ms (0 if not a streaming trace)
 303      */
 304     long getStreamingInterval();
 305
 306     // ------------------------------------------------------------------------
 307     // Trace positioning getters
 308     // ------------------------------------------------------------------------
 309
 310     /**
 311      * @return the current trace location
 312      */
 313     ITmfLocation getCurrentLocation();
 314
 315     /**
 316      * Returns the ratio (proportion) corresponding to the specified location.
 317      *
 318      * @param location
 319      *            a trace specific location
 320      * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
 321      */
 322     double getLocationRatio(ITmfLocation location);
 323
 324     // ------------------------------------------------------------------------
 325     // SeekEvent operations (returning a trace context)
 326     // ------------------------------------------------------------------------
 327
 328     /**
 329      * Position the trace at the specified (trace specific) location.
 330      * <p>
 331      * A null location is interpreted as seeking for the first event of the
 332      * trace.
 333      * <p>
 334      * If not null, the location requested must be valid otherwise the returned
 335      * context is undefined (up to the implementation to recover if possible).
 336      * <p>
 337      *
 338      * @param location
 339      *            the trace specific location
 340      * @return a context which can later be used to read the corresponding event
 341      */
 342     ITmfContext seekEvent(ITmfLocation location);
 343
 344     /**
 345      * Position the trace at the 'rank'th event in the trace.
 346      * <p>
 347      * A rank <= 0 is interpreted as seeking for the first event of the trace.
 348      * <p>
 349      * If the requested rank is beyond the last trace event, the context
 350      * returned will yield a null event if used in a subsequent read.
 351      *
 352      * @param rank
 353      *            the event rank
 354      * @return a context which can later be used to read the corresponding event
 355      */
 356     ITmfContext seekEvent(long rank);
 357
 358     /**
 359      * Position the trace at the first event with the specified timestamp. If
 360      * there is no event with the requested timestamp, a context pointing to the
 361      * next chronological event is returned.
 362      * <p>
 363      * A null timestamp is interpreted as seeking for the first event of the
 364      * trace.
 365      * <p>
 366      * If the requested timestamp is beyond the last trace event, the context
 367      * returned will yield a null event if used in a subsequent read.
 368      *
 369      * @param timestamp
 370      *            the timestamp of desired event
 371      * @return a context which can later be used to read the corresponding event
 372      */
 373     ITmfContext seekEvent(ITmfTimestamp timestamp);
 374
 375     /**
 376      * Position the trace at the event located at the specified ratio in the
 377      * trace file.
 378      * <p>
 379      * The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
 380      * voluntarily vague. Typically, it would refer to the event proportional
 381      * rank (arguably more intuitive) or timestamp in the trace file.
 382      *
 383      * @param ratio
 384      *            the proportional 'rank' in the trace
 385      * @return a context which can later be used to read the corresponding event
 386      */
 387     ITmfContext seekEvent(double ratio);
 388
 389     /**
 390      * Returns the initial range offset
 391      *
 392      * @return the initial range offset
 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      */
 406     @NonNull String getHostId();
 407
 408     // ------------------------------------------------------------------------
 409     // Timestamp transformation functions
 410     // ------------------------------------------------------------------------
 411
 412     /**
 413      * Returns the timestamp transformation for this trace
 414      *
 415      * @return the timestamp transform
 416      */
 417     ITmfTimestampTransform getTimestampTransform();
 418
 419     /**
 420      * Sets the trace's timestamp transform
 421      *
 422      * @param tt
 423      *            The timestamp transform for all timestamps of this trace
 424      */
 425     void setTimestampTransform(final ITmfTimestampTransform tt);
 426
 427     /**
 428      * Creates a timestamp for this trace, using the transformation formula
 429      *
 430      * @param ts
 431      *            The time in nanoseconds with which to create the timestamp
 432      * @return The new timestamp
 433      */
 434     @NonNull ITmfTimestamp createTimestamp(long ts);
 435
 436 }