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 java
.io
.FileNotFoundException
;
18 import org
.eclipse
.core
.resources
.IProject
;
19 import org
.eclipse
.core
.resources
.IResource
;
20 import org
.eclipse
.linuxtools
.tmf
.core
.component
.ITmfDataProvider
;
21 import org
.eclipse
.linuxtools
.tmf
.core
.event
.ITmfEvent
;
22 import org
.eclipse
.linuxtools
.tmf
.core
.event
.ITmfTimestamp
;
23 import org
.eclipse
.linuxtools
.tmf
.core
.event
.TmfTimeRange
;
26 * <b><u>ITmfTrace</u></b>
28 * The event stream structure in TMF. In its basic form, a trace has:
30 * <li> the associated Eclipse resource
31 * <li> the path to its location on the file system
32 * <li> the type of the events it contains
33 * <li> the number of events it contains
34 * <li> the time range (span) of the events it contains
36 * Concrete ITmfTrace classes have to provide a parameter-less constructor and
37 * an initialization method (initTace())if they are to be opened from the
38 * Project View. Also, a validation (validate()) method has to be provided to
39 * ensure that the trace is of the correct type.
41 * A trace can be accessed simultaneously from multiple threads by various
42 * application components. To avoid obvious multi-threading issues, the trace
43 * uses an ITmfContext as a synchronization aid for its read operations.
45 * A proper ITmfContext can be obtained by performing a seek operation on the
46 * trace. Seek operations can be performed for a particular event (by rank or
47 * timestamp) or for a plain trace location.
49 * <b>Example 1</b>: Read a whole trace
51 * ITmfContext context = trace.seekLocationt(null);
52 * ITmfEvent event = trace.getEvent(context);
53 * while (event != null) {
55 * event = trace.getEvent(context);
58 * <b>Example 2</b>: Process 50 events starting from the 1000th event
60 * int nbEventsRead = 0;
61 * ITmfContext context = trace.seekEvent(1000);
62 * ITmfEvent event = trace.getEvent(context);
63 * while (event != null && nbEventsRead < 50) {
66 * event = trace.getEvent(context);
69 * <b>Example 3</b>: Process the events between 2 timestamps (inclusive)
71 * ITmfTimestamp startTime = ...;
72 * ITmfTimestamp endTime = ...;
73 * ITmfContext context = trace.seekEvent(startTime);
74 * ITmfEvent event = trace.getEvent(context);
75 * while (event != null && event.getTimestamp().compareTo(endTime) <= 0) {
77 * event = trace.getEvent(context);
81 public interface ITmfTrace
<T
extends ITmfEvent
> extends ITmfDataProvider
<T
> {
83 // ------------------------------------------------------------------------
85 // ------------------------------------------------------------------------
88 * Initialize a newly instantiated "empty" trace object. This is used to
89 * properly parameterize an ITmfTrace instantiated with its parameterless
92 * Typically, the parameterless constructor will provide the block size
93 * and its associated parser and indexer.
95 * @param resource the trace resource
96 * @param path the trace path
97 * @param type the trace event type
98 * @throws FileNotFoundException
100 public void initTrace(IResource resource
, String path
, Class
<T
> type
) throws FileNotFoundException
;
103 * Validate that the trace is of the correct type.
105 * @param project the eclipse project
106 * @param path the trace path
108 * @return true if trace is valid
110 public boolean validate(IProject project
, String path
);
112 // ------------------------------------------------------------------------
114 // ------------------------------------------------------------------------
117 * @return the trace event type
119 public Class
<T
> getType();
122 * @return the associated trace resource
124 public IResource
getResource();
127 * @return the trace path
129 public String
getPath();
132 * @return the trace cache size
134 public int getCacheSize();
136 // ------------------------------------------------------------------------
137 // Trace characteristics getters
138 // ------------------------------------------------------------------------
141 * @return the number of events in the trace
143 public long getNbEvents();
146 * @return the trace time range
148 public TmfTimeRange
getTimeRange();
151 * @return the timestamp of the first trace event
153 public ITmfTimestamp
getStartTime();
156 * @return the timestamp of the last trace event
158 public ITmfTimestamp
getEndTime();
160 // ------------------------------------------------------------------------
161 // Trace positioning getters
162 // ------------------------------------------------------------------------
165 * @return the current trace location
167 public ITmfLocation
<?
> getCurrentLocation();
170 * Returns the ratio (proportion) corresponding to the specified location.
172 * @param location a trace specific location
173 * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
175 public double getLocationRatio(ITmfLocation
<?
> location
);
177 // ------------------------------------------------------------------------
178 // Seek operations (returning a reading context)
179 // ------------------------------------------------------------------------
182 * Position the trace at the specified location. The null location
183 * is used to indicate that the first trace event is requested.
186 * <li> a <b>null</b> location returns the context of the first event
187 * <li> an invalid location, including beyond the last event, returns a null context
190 * @param location the trace specific location (null for 1st event)
191 * @return a context which can later be used to read the corresponding event
193 public ITmfContext
seekLocation(ITmfLocation
<?
> location
);
196 * Position the trace at the event located at the specified ratio in the
199 * The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
200 * voluntarily vague. Typically, it would refer to the event proportional
201 * rank (arguably more intuitive) or timestamp in the trace file.
203 * @param ratio the proportional 'rank' in the trace
204 * @return a context which can later be used to read the corresponding event
206 public ITmfContext
seekLocation(double ratio
);
209 * Position the trace at the first event with the specified timestamp. If
210 * there is no event with the requested timestamp, a context pointing to
211 * the next chronological event is returned.
213 * A null timestamp is interpreted as seeking for the first event of the
216 * If the requested timestamp is beyond the last trace event, the context
217 * returned will yield a null event if used in a subsequent read.
219 * @param timestamp the timestamp of desired event
220 * @return a context which can later be used to read the corresponding event
222 public ITmfContext
seekEvent(ITmfTimestamp timestamp
);
225 * Position the trace at the 'rank'th event in the trace.
227 * If the requested rank is beyond the last trace event, the context
228 * returned will yield a null event if used in a subsequent read.
230 * @param rank the event rank
231 * @return a context which can later be used to read the corresponding event
233 public ITmfContext
seekEvent(long rank
);
235 // ------------------------------------------------------------------------
236 // Read operations (returning an actual event)
237 // ------------------------------------------------------------------------
240 * Return the event pointed by the supplied context (or null if no event
241 * left) and updates the context to point the next event.
243 * @param context the read context (will be updated)
244 * @return the event pointed to by the context
246 public ITmfEvent
getNextEvent(ITmfContext context
);
249 * Return the event pointed by the supplied context (or null if no event
250 * left) and *does not* update the context.
252 * @param context the read context
253 * @return the next event in the stream
255 public ITmfEvent
parseEvent(ITmfContext context
);
257 // ------------------------------------------------------------------------
258 // ------------------------------------------------------------------------
261 * @return the streaming interval in ms (0 if not a streaming trace)
263 public long getStreamingInterval();
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