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
;
23 import org
.eclipse
.linuxtools
.tmf
.core
.request
.ITmfEventRequest
;
26 * The event stream structure in TMF. In its basic form, a trace has:
28 * <li> an associated Eclipse resource
29 * <li> a path to its location on the file system
30 * <li> the type of the events it contains
31 * <li> the number of events it contains
32 * <li> the time range (span) of the events it contains
34 * Concrete ITmfTrace classes have to provide a parameter-less constructor and
35 * an initialization method (<i>initTrace</i>) if they are to be opened from
36 * the Project View. Also, a validation method (<i>validate</i>) has to be
37 * provided to ensure that the trace is of the correct type.
39 * A trace can be accessed simultaneously from multiple threads by various
40 * application components. To avoid obvious multi-threading issues, the trace
41 * uses an ITmfContext as a synchronization aid for its read operations.
43 * A proper ITmfContext can be obtained by performing a seek operation on the
44 * trace. Seek operations can be performed for a particular event (by rank or
45 * timestamp) or for a plain trace location.
47 * <b>Example 1</b>: Process a whole trace
49 * ITmfContext context = trace.seekEvent(0);
50 * ITmfEvent event = trace.readEvent(context);
51 * while (event != null) {
52 * processEvent(event);
53 * event = trace.readNextEvent(context);
56 * <b>Example 2</b>: Process 50 events starting from the 1000th event
58 * int nbEventsRead = 0;
59 * ITmfContext context = trace.seekEvent(1000);
60 * ITmfEvent event = trace.readNextEvent(context);
61 * while (event != null && nbEventsRead < 50) {
63 * processEvent(event);
64 * event = trace.readNextEvent(context);
67 * <b>Example 3</b>: Process the events between 2 timestamps (inclusive)
69 * ITmfTimestamp startTime = ...;
70 * ITmfTimestamp endTime = ...;
71 * ITmfContext context = trace.seekEvent(startTime);
72 * ITmfEvent event = trace.readNextEvent(context);
73 * while (event != null && event.getTimestamp().compareTo(endTime) <= 0) {
74 * processEvent(event);
75 * event = trace.readNextEvent(context);
78 * A trace is also an event provider so it can process event requests
79 * asynchronously (and coalesce compatible, concurrent requests).
82 * <b>Example 4</b>: Process a whole trace (see ITmfEventRequest for variants)
84 * ITmfRequest request = new TmfEventRequest<MyEventType>(MyEventType.class) {
86 * public void handleData(MyEventType event) {
87 * super.handleData(event);
88 * processEvent(event);
91 * public void handleCompleted() {
93 * super.handleCompleted();
97 * fTrace.handleRequest(request);
99 * request.waitForCompletion();
105 * @author Francois Chouinard
108 * @see ITmfDataProvider
109 * @see ITmfEventRequest
112 public interface ITmfTrace
<T
extends ITmfEvent
> extends ITmfDataProvider
<T
> {
114 // ------------------------------------------------------------------------
116 // ------------------------------------------------------------------------
119 * Initialize a newly instantiated "empty" trace object. This is used to
120 * properly parameterize an ITmfTrace instantiated with its parameterless
123 * Typically, the parameterless constructor will provide the block size
124 * and its associated parser and indexer.
126 * @param resource the trace resource
127 * @param path the trace path
128 * @param type the trace event type
129 * @throws TmfTraceException
131 public void initTrace(IResource resource
, String path
, Class
<T
> type
) throws TmfTraceException
;
134 * Validate that the trace is of the correct type.
136 * @param project the eclipse project
137 * @param path the trace path
139 * @return true if trace is valid
141 public boolean validate(IProject project
, String path
);
143 // ------------------------------------------------------------------------
145 // ------------------------------------------------------------------------
148 * @return the trace event type
150 public Class
<T
> getEventType();
153 * @return the associated trace resource
155 public IResource
getResource();
158 * @return the trace path
160 public String
getPath();
163 * @return the trace cache size
165 public int getCacheSize();
167 // ------------------------------------------------------------------------
168 // Trace characteristics getters
169 // ------------------------------------------------------------------------
172 * @return the number of events in the trace
174 public long getNbEvents();
177 * @return the trace time range
179 public TmfTimeRange
getTimeRange();
182 * @return the timestamp of the first trace event
184 public ITmfTimestamp
getStartTime();
187 * @return the timestamp of the last trace event
189 public ITmfTimestamp
getEndTime();
192 * @return the streaming interval in ms (0 if not a streaming trace)
194 public long getStreamingInterval();
196 // ------------------------------------------------------------------------
197 // Trace positioning getters
198 // ------------------------------------------------------------------------
201 * @return the current trace location
203 public ITmfLocation
<?
> getCurrentLocation();
206 * Returns the ratio (proportion) corresponding to the specified location.
208 * @param location a trace specific location
209 * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
211 public double getLocationRatio(ITmfLocation
<?
> location
);
213 // ------------------------------------------------------------------------
214 // SeekEvent operations (returning a trace context)
215 // ------------------------------------------------------------------------
218 * Position the trace at the specified (trace specific) location.
220 * A null location is interpreted as seeking for the first event of the
223 * If not null, the location requested must be valid otherwise the returned
224 * context is undefined (up to the implementation to recover if possible).
226 * @param location the trace specific location
227 * @return a context which can later be used to read the corresponding event
229 public ITmfContext
seekEvent(ITmfLocation
<?
> location
);
232 * Position the trace at the 'rank'th event in the trace.
234 * A rank <= 0 is interpreted as seeking for the first event of the
237 * If the requested rank is beyond the last trace event, the context
238 * returned will yield a null event if used in a subsequent read.
240 * @param rank the event rank
241 * @return a context which can later be used to read the corresponding event
243 public ITmfContext
seekEvent(long rank
);
246 * Position the trace at the first event with the specified timestamp. If
247 * there is no event with the requested timestamp, a context pointing to
248 * the next chronological event is returned.
250 * A null timestamp is interpreted as seeking for the first event of the
253 * If the requested timestamp is beyond the last trace event, the context
254 * returned will yield a null event if used in a subsequent read.
256 * @param timestamp the timestamp of desired event
257 * @return a context which can later be used to read the corresponding event
259 public ITmfContext
seekEvent(ITmfTimestamp timestamp
);
262 * Position the trace at the event located at the specified ratio in the
265 * The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
266 * voluntarily vague. Typically, it would refer to the event proportional
267 * rank (arguably more intuitive) or timestamp in the trace file.
269 * @param ratio the proportional 'rank' in the trace
270 * @return a context which can later be used to read the corresponding event
272 public ITmfContext
seekEvent(double ratio
);
274 // ------------------------------------------------------------------------
275 // Read operations (returning an actual event)
276 // ------------------------------------------------------------------------
279 * Return the event pointed by the supplied context (or null if no event
280 * left) and updates the context to point the next event.
282 * @param context the read context (will be updated)
283 * @return the event pointed to by the context
285 public ITmfEvent
readNextEvent(ITmfContext context
);
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