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/*******************************************************************************
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* Copyright (c) 2009, 2011, 2012 Ericsson
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* All rights reserved. This program and the accompanying materials are
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* made available under the terms of the Eclipse Public License v1.0 which
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* accompanies this distribution, and is available at
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* http://www.eclipse.org/legal/epl-v10.html
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* Francois Chouinard - Initial API and implementation
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* Francois Chouinard - Updated as per TMF Trace Model 1.0
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*******************************************************************************/
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package org.eclipse.linuxtools.tmf.core.trace;
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import org.eclipse.core.resources.IProject;
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import org.eclipse.core.resources.IResource;
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import org.eclipse.linuxtools.tmf.core.component.ITmfDataProvider;
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import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
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import org.eclipse.linuxtools.tmf.core.event.ITmfTimestamp;
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import org.eclipse.linuxtools.tmf.core.event.TmfTimeRange;
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import org.eclipse.linuxtools.tmf.core.exceptions.TmfTraceException;
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* The event stream structure in TMF. In its basic form, a trace has:
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* <li> an associated Eclipse resource
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* <li> a path to its location on the file system
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* <li> the type of the events it contains
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* <li> the number of events it contains
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* <li> the time range (span) of the events it contains
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* Concrete ITmfTrace classes have to provide a parameter-less constructor and
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* an initialization method (<i>initTrace</i>) if they are to be opened from
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* the Project View. Also, a validation method (<i>validate</i>) has to be
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* provided to ensure that the trace is of the correct type.
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* A trace can be accessed simultaneously from multiple threads by various
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* application components. To avoid obvious multi-threading issues, the trace
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* uses an ITmfContext as a synchronization aid for its read operations.
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* A proper ITmfContext can be obtained by performing a seek operation on the
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* trace. Seek operations can be performed for a particular event (by rank or
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* timestamp) or for a plain trace location.
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* <b>Example 1</b>: Process a whole trace
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* ITmfContext context = trace.seekEvent(0);
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* ITmfEvent event = trace.getNext(context);
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* while (event != null) {
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* processEvent(event);
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* event = trace.getNext(context);
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* <b>Example 2</b>: Process 50 events starting from the 1000th event
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* int nbEventsRead = 0;
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* ITmfContext context = trace.seekEvent(1000);
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* ITmfEvent event = trace.getNext(context);
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* while (event != null && nbEventsRead < 50) {
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* processEvent(event);
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* event = trace.getNext(context);
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* <b>Example 3</b>: Process the events between 2 timestamps (inclusive)
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* ITmfTimestamp startTime = ...;
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* ITmfTimestamp endTime = ...;
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* ITmfContext context = trace.seekEvent(startTime);
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* ITmfEvent event = trace.getNext(context);
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* while (event != null && event.getTimestamp().compareTo(endTime) <= 0) {
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* processEvent(event);
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* event = trace.getNext(context);
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* A trace is also an event provider so it can process event requests
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* asynchronously (and coalesce compatible, concurrent requests).
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* <b>Example 4</b>: Process a whole trace (see ITmfEventRequest for variants)
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* ITmfRequest request = new TmfEventRequest<MyEventType>(MyEventType.class) {
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* public void handleData(MyEventType event) {
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* super.handleData(event);
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* processEvent(event);
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* public void handleCompleted() {
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* super.handleCompleted();
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* fTrace.handleRequest(request);
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* request.waitForCompletion();
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* @author Francois Chouinard
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* @see ITmfTraceIndexer
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* @see ITmfEventParser
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public interface ITmfTrace<T extends ITmfEvent> extends ITmfDataProvider<T> {
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// ------------------------------------------------------------------------
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// ------------------------------------------------------------------------
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* The default trace cache size
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public static final int DEFAULT_TRACE_CACHE_SIZE = 1000;
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// ------------------------------------------------------------------------
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// ------------------------------------------------------------------------
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* Initialize a newly instantiated "empty" trace object. This is used to
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* properly parameterize an ITmfTrace instantiated with its parameterless
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* Typically, the parameterless constructor will provide the block size
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* and its associated parser and indexer.
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* @param resource the trace resource
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* @param path the trace path
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* @param type the trace event type
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* @throws TmfTraceException
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public void initTrace(IResource resource, String path, Class<T> type) throws TmfTraceException;
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* Validate that the trace is of the correct type.
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* @param project the eclipse project
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* @param path the trace path
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* @return true if trace is valid
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public boolean validate(IProject project, String path);
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// ------------------------------------------------------------------------
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// ------------------------------------------------------------------------
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* @return the trace event type
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public Class<T> getEventType();
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* @return the associated trace resource
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public IResource getResource();
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* @return the trace path
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public String getPath();
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* @return the trace cache size
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public int getCacheSize();
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// ------------------------------------------------------------------------
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// Trace characteristics getters
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// ------------------------------------------------------------------------
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* @return the number of events in the trace
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public long getNbEvents();
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* @return the trace time range
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public TmfTimeRange getTimeRange();
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* @return the timestamp of the first trace event
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public ITmfTimestamp getStartTime();
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* @return the timestamp of the last trace event
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public ITmfTimestamp getEndTime();
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* @return the streaming interval in ms (0 if not a streaming trace)
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public long getStreamingInterval();
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// ------------------------------------------------------------------------
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// Trace positioning getters
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// ------------------------------------------------------------------------
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* @return the current trace location
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public ITmfLocation<?> getCurrentLocation();
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* Returns the ratio (proportion) corresponding to the specified location.
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* @param location a trace specific location
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* @return a floating-point number between 0.0 (beginning) and 1.0 (end)
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public double getLocationRatio(ITmfLocation<?> location);
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// ------------------------------------------------------------------------
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// SeekEvent operations (returning a trace context)
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// ------------------------------------------------------------------------
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* Position the trace at the specified (trace specific) location.
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* A null location is interpreted as seeking for the first event of the
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* If not null, the location requested must be valid otherwise the returned
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* context is undefined (up to the implementation to recover if possible).
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* @param location the trace specific location
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* @return a context which can later be used to read the corresponding event
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public ITmfContext seekEvent(ITmfLocation<?> location);
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* Position the trace at the 'rank'th event in the trace.
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* A rank <= 0 is interpreted as seeking for the first event of the
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* If the requested rank is beyond the last trace event, the context
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* returned will yield a null event if used in a subsequent read.
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* @param rank the event rank
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* @return a context which can later be used to read the corresponding event
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public ITmfContext seekEvent(long rank);
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* Position the trace at the first event with the specified timestamp. If
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* there is no event with the requested timestamp, a context pointing to
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* the next chronological event is returned.
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* A null timestamp is interpreted as seeking for the first event of the
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* If the requested timestamp is beyond the last trace event, the context
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* returned will yield a null event if used in a subsequent read.
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* @param timestamp the timestamp of desired event
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* @return a context which can later be used to read the corresponding event
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public ITmfContext seekEvent(ITmfTimestamp timestamp);
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* Position the trace at the event located at the specified ratio in the
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* The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
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* voluntarily vague. Typically, it would refer to the event proportional
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* rank (arguably more intuitive) or timestamp in the trace file.
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* @param ratio the proportional 'rank' in the trace
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* @return a context which can later be used to read the corresponding event
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public ITmfContext seekEvent(double ratio);