1 /*******************************************************************************
2 * Copyright (c) 2009, 2011, 2012 Ericsson
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
10 * Francois Chouinard - Initial API and implementation
11 * Francois Chouinard - Updated as per TMF Trace Model 1.0
12 *******************************************************************************/
14 package org
.eclipse
.linuxtools
.tmf
.core
.trace
;
16 import org
.eclipse
.core
.resources
.IProject
;
17 import org
.eclipse
.core
.resources
.IResource
;
18 import org
.eclipse
.linuxtools
.tmf
.core
.component
.ITmfDataProvider
;
19 import org
.eclipse
.linuxtools
.tmf
.core
.event
.ITmfEvent
;
20 import org
.eclipse
.linuxtools
.tmf
.core
.event
.ITmfTimestamp
;
21 import org
.eclipse
.linuxtools
.tmf
.core
.event
.TmfTimeRange
;
22 import org
.eclipse
.linuxtools
.tmf
.core
.exceptions
.TmfTraceException
;
25 * The event stream structure in TMF. In its basic form, a trace has:
27 * <li> an associated Eclipse resource
28 * <li> a path to its location on the file system
29 * <li> the type of the events it contains
30 * <li> the number of events it contains
31 * <li> the time range (span) of the events it contains
33 * Concrete ITmfTrace classes have to provide a parameter-less constructor and
34 * an initialization method (<i>initTrace</i>) if they are to be opened from
35 * the Project View. Also, a validation method (<i>validate</i>) has to be
36 * provided to ensure that the trace is of the correct type.
38 * A trace can be accessed simultaneously from multiple threads by various
39 * application components. To avoid obvious multi-threading issues, the trace
40 * uses an ITmfContext as a synchronization aid for its read operations.
42 * A proper ITmfContext can be obtained by performing a seek operation on the
43 * trace. Seek operations can be performed for a particular event (by rank or
44 * timestamp) or for a plain trace location.
46 * <b>Example 1</b>: Process a whole trace
48 * ITmfContext context = trace.seekEvent(0);
49 * ITmfEvent event = trace.readEvent(context);
50 * while (event != null) {
51 * processEvent(event);
52 * event = trace.readNextEvent(context);
55 * <b>Example 2</b>: Process 50 events starting from the 1000th event
57 * int nbEventsRead = 0;
58 * ITmfContext context = trace.seekEvent(1000);
59 * ITmfEvent event = trace.readNextEvent(context);
60 * while (event != null && nbEventsRead < 50) {
62 * processEvent(event);
63 * event = trace.readNextEvent(context);
66 * <b>Example 3</b>: Process the events between 2 timestamps (inclusive)
68 * ITmfTimestamp startTime = ...;
69 * ITmfTimestamp endTime = ...;
70 * ITmfContext context = trace.seekEvent(startTime);
71 * ITmfEvent event = trace.readNextEvent(context);
72 * while (event != null && event.getTimestamp().compareTo(endTime) <= 0) {
73 * processEvent(event);
74 * event = trace.readNextEvent(context);
77 * A trace is also an event provider so it can process event requests
78 * asynchronously (and coalesce compatible, concurrent requests).
81 * <b>Example 4</b>: Process a whole trace (see ITmfEventRequest for variants)
83 * ITmfRequest request = new TmfEventRequest<MyEventType>(MyEventType.class) {
85 * public void handleData(MyEventType event) {
86 * super.handleData(event);
87 * processEvent(event);
90 * public void handleCompleted() {
92 * super.handleCompleted();
96 * fTrace.handleRequest(request);
98 * request.waitForCompletion();
103 * @author Francois Chouinard
107 * @see ITmfTraceIndexer
108 * @see ITmfEventParser
110 public interface ITmfTrace
<T
extends ITmfEvent
> extends ITmfDataProvider
<T
> {
112 // ------------------------------------------------------------------------
114 // ------------------------------------------------------------------------
117 * The default trace cache size
119 public static final int DEFAULT_TRACE_CACHE_SIZE
= 1000;
121 // ------------------------------------------------------------------------
123 // ------------------------------------------------------------------------
126 * Initialize a newly instantiated "empty" trace object. This is used to
127 * properly parameterize an ITmfTrace instantiated with its parameterless
130 * Typically, the parameterless constructor will provide the block size
131 * and its associated parser and indexer.
133 * @param resource the trace resource
134 * @param path the trace path
135 * @param type the trace event type
136 * @throws TmfTraceException
138 public void initTrace(IResource resource
, String path
, Class
<T
> type
) throws TmfTraceException
;
141 * Validate that the trace is of the correct type.
143 * @param project the eclipse project
144 * @param path the trace path
146 * @return true if trace is valid
148 public boolean validate(IProject project
, String path
);
150 // ------------------------------------------------------------------------
152 // ------------------------------------------------------------------------
155 * @return the trace event type
157 public Class
<T
> getEventType();
160 * @return the associated trace resource
162 public IResource
getResource();
165 * @return the trace path
167 public String
getPath();
170 * @return the trace cache size
172 public int getCacheSize();
174 // ------------------------------------------------------------------------
175 // Trace characteristics getters
176 // ------------------------------------------------------------------------
179 * @return the number of events in the trace
181 public long getNbEvents();
184 * @return the trace time range
186 public TmfTimeRange
getTimeRange();
189 * @return the timestamp of the first trace event
191 public ITmfTimestamp
getStartTime();
194 * @return the timestamp of the last trace event
196 public ITmfTimestamp
getEndTime();
199 * @return the streaming interval in ms (0 if not a streaming trace)
201 public long getStreamingInterval();
203 // ------------------------------------------------------------------------
204 // Trace positioning getters
205 // ------------------------------------------------------------------------
208 * @return the current trace location
210 public ITmfLocation
<?
> getCurrentLocation();
213 * Returns the ratio (proportion) corresponding to the specified location.
215 * @param location a trace specific location
216 * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
218 public double getLocationRatio(ITmfLocation
<?
> location
);
220 // ------------------------------------------------------------------------
221 // SeekEvent operations (returning a trace context)
222 // ------------------------------------------------------------------------
225 * Position the trace at the specified (trace specific) location.
227 * A null location is interpreted as seeking for the first event of the
230 * If not null, the location requested must be valid otherwise the returned
231 * context is undefined (up to the implementation to recover if possible).
233 * @param location the trace specific location
234 * @return a context which can later be used to read the corresponding event
236 public ITmfContext
seekEvent(ITmfLocation
<?
> location
);
239 * Position the trace at the 'rank'th event in the trace.
241 * A rank <= 0 is interpreted as seeking for the first event of the
244 * If the requested rank is beyond the last trace event, the context
245 * returned will yield a null event if used in a subsequent read.
247 * @param rank the event rank
248 * @return a context which can later be used to read the corresponding event
250 public ITmfContext
seekEvent(long rank
);
253 * Position the trace at the first event with the specified timestamp. If
254 * there is no event with the requested timestamp, a context pointing to
255 * the next chronological event is returned.
257 * A null timestamp is interpreted as seeking for the first event of the
260 * If the requested timestamp is beyond the last trace event, the context
261 * returned will yield a null event if used in a subsequent read.
263 * @param timestamp the timestamp of desired event
264 * @return a context which can later be used to read the corresponding event
266 public ITmfContext
seekEvent(ITmfTimestamp timestamp
);
269 * Position the trace at the event located at the specified ratio in the
272 * The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
273 * voluntarily vague. Typically, it would refer to the event proportional
274 * rank (arguably more intuitive) or timestamp in the trace file.
276 * @param ratio the proportional 'rank' in the trace
277 * @return a context which can later be used to read the corresponding event
279 public ITmfContext
seekEvent(double ratio
);
281 // ------------------------------------------------------------------------
282 // Read operations (returning an actual event)
283 // ------------------------------------------------------------------------
286 * Return the event pointed by the supplied context (or null if no event
287 * left) and updates the context to point the next event.
289 * @param context the read context (will be updated)
290 * @return the event pointed to by the context
292 public ITmfEvent
readNextEvent(ITmfContext context
);
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