Added TMF statistics feature (Bug 360572)

[deliverable/tracecompass.git] / org.eclipse.linuxtools.lttng / src / org / eclipse / linuxtools / lttng / trace / LTTngTrace.java

/*******************************************************************************
 * Copyright (c) 2009, 2011 Ericsson, MontaVista Software
 * 
 * All rights reserved. This program and the accompanying materials are
 * made available under the terms of the Eclipse Public License v1.0 which
 * accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *   William Bourque (wbourque@gmail.com) - Initial API and implementation
 *   Yufen Kuo       (ykuo@mvista.com) - add support to allow user specify trace library path
 *******************************************************************************/

package org.eclipse.linuxtools.lttng.trace;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Vector;

import org.eclipse.linuxtools.lttng.event.LttngEvent;
import org.eclipse.linuxtools.lttng.event.LttngEventContent;
import org.eclipse.linuxtools.lttng.event.LttngEventReference;
import org.eclipse.linuxtools.lttng.event.LttngEventSource;
import org.eclipse.linuxtools.lttng.event.LttngEventType;
import org.eclipse.linuxtools.lttng.event.LttngLocation;
import org.eclipse.linuxtools.lttng.event.LttngTimestamp;
import org.eclipse.linuxtools.lttng.exceptions.LttngException;
import org.eclipse.linuxtools.lttng.jni.JniEvent;
import org.eclipse.linuxtools.lttng.jni.JniMarker;
import org.eclipse.linuxtools.lttng.jni.JniTrace;
import org.eclipse.linuxtools.lttng.jni.JniTracefile;
import org.eclipse.linuxtools.lttng.jni.common.JniTime;
import org.eclipse.linuxtools.lttng.jni.exception.JniException;
import org.eclipse.linuxtools.lttng.jni.factory.JniTraceFactory;
import org.eclipse.linuxtools.tmf.event.TmfTimeRange;
import org.eclipse.linuxtools.tmf.event.TmfTimestamp;
import org.eclipse.linuxtools.tmf.trace.ITmfContext;
import org.eclipse.linuxtools.tmf.trace.ITmfLocation;
import org.eclipse.linuxtools.tmf.trace.TmfCheckpoint;
import org.eclipse.linuxtools.tmf.trace.TmfContext;
import org.eclipse.linuxtools.tmf.trace.TmfTrace;

class LTTngTraceException extends LttngException {
	static final long serialVersionUID = -1636648737081868146L;

	public LTTngTraceException(String errMsg) {
		super(errMsg);
	}
}

/**
 * <b><u>LTTngTrace</u></b>
 * <p>
 * 
 * LTTng trace implementation. It accesses the C trace handling library
 * (seeking, reading and parsing) through the JNI component.
 */
public class LTTngTrace extends TmfTrace<LttngEvent> {

	public static boolean PrintDebug = false;
	public static boolean UniqueEvent = true;

	private final static boolean SHOW_LTT_DEBUG_DEFAULT = false;
	private final static boolean IS_PARSING_NEEDED_DEFAULT = !UniqueEvent;
	private final static int CHECKPOINT_PAGE_SIZE = 50000;

	// Reference to our JNI trace
	private JniTrace currentJniTrace = null;

	// ***
	// UNHACKED : We can no longer do that because TCF need to maintain several
	// events at once.
	// This is very slow to do so in LTTng, this has to be temporary.
	// *** HACK ***
	// To save time, we will declare all component of the LttngEvent during the
	// construction of the trace
	// Then, while reading the trace, we will just SET the values instead of
	// declaring new object
	// ***
	LttngTimestamp eventTimestamp = null;
	LttngEventSource eventSource = null;
	LttngEventContent eventContent = null;
	LttngEventReference eventReference = null;

	// The actual event
	LttngEvent currentLttngEvent = null;

	// The current location
	LttngLocation previousLocation = null;

	LttngEventType eventType = null;
	// Hashmap of the possible types of events (Tracefile/CPU/Marker in the JNI)
	HashMap<Integer, LttngEventType> traceTypes = null;
	// This vector will be used to quickly find a marker name from a position
	Vector<Integer> traceTypeNames = null;
    private String traceLibPath;
	/**
	 * Default Constructor.
	 * <p>
	 * 
	 * @param path
	 *            Path to a <b>directory</b> that contain an LTTng trace.
	 * 
	 * @exception Exception
	 *                (most likely LTTngTraceException or FileNotFoundException)
	 */
	public LTTngTrace(String path) throws Exception {
		// Call with "wait for completion" true and "skip indexing" false
		this(path, null, true, false);
	}

	/**
	 * Constructor, with control over the indexing.
	 * <p>
	 * 
	 * @param path
	 *            Path to a <b>directory</b> that contain an LTTng trace.
	 * @param waitForCompletion
	 *            Should we wait for indexign to complete before moving on.
	 * 
	 * @exception Exception
	 *                (most likely LTTngTraceException or FileNotFoundException)
	 */
	public LTTngTrace(String path, boolean waitForCompletion) throws Exception {
		// Call with "skip indexing" false
		this(path, null, waitForCompletion, false);
	}

	/**
	 * Default constructor, with control over the indexing and possibility to
	 * bypass indexation
	 * <p>
	 * 
	 * @param path
	 *            Path to a <b>directory</b> that contain an LTTng trace.
	 * @param traceLibPath
     *            Path to a <b>directory</b> that contains LTTng trace libraries.
	 * @param waitForCompletion
	 *            Should we wait for indexign to complete before moving on.
	 * @param bypassIndexing
	 *            Should we bypass indexing completly? This is should only be
	 *            useful for unit testing.
	 * 
	 * @exception Exception
	 *                (most likely LTTngTraceException or FileNotFoundException)
	 * 
	 */
	public LTTngTrace(String path, String traceLibPath, boolean waitForCompletion,
			boolean bypassIndexing) throws Exception {
		super(path, LttngEvent.class, path, CHECKPOINT_PAGE_SIZE, false);
		try {
			currentJniTrace = JniTraceFactory.getJniTrace(path, traceLibPath,
					SHOW_LTT_DEBUG_DEFAULT);
		} catch (Exception e) {
			throw new LTTngTraceException(e.getMessage());
		}

		this.traceLibPath = traceLibPath;
		// Export all the event types from the JNI side
		traceTypes = new HashMap<Integer, LttngEventType>();
		traceTypeNames = new Vector<Integer>();
		initialiseEventTypes(currentJniTrace);

		// *** VERIFY ***
		// Verify that all those "default constructor" are safe to use
		eventTimestamp = new LttngTimestamp();
		eventSource = new LttngEventSource();
		eventType = new LttngEventType();
		eventContent = new LttngEventContent(currentLttngEvent);
		eventReference = new LttngEventReference(this.getName());

		// Create the skeleton event
		currentLttngEvent = new LttngEvent(this, eventTimestamp, eventSource,
				eventType, eventContent, eventReference, null);

		// Create a new current location
		previousLocation = new LttngLocation();

		// Set the currentEvent to the eventContent
		eventContent.setEvent(currentLttngEvent);

		// // Bypass indexing if asked
		// if ( bypassIndexing == false ) {
		// indexTrace(true);
		// }
		// else {
		// Even if we don't have any index, set ONE checkpoint
		// fCheckpoints.add(new TmfCheckpoint(new LttngTimestamp(0L) , new
		// LttngLocation() ) );

		// Set the time range of the trace
		TmfContext context = seekLocation(null);
		LttngEvent event = getNextEvent(context);
		LttngTimestamp startTime = new LttngTimestamp(event.getTimestamp());
		LttngTimestamp endTime = new LttngTimestamp(currentJniTrace
				.getEndTime().getTime());

		setTimeRange(new TmfTimeRange(startTime, endTime));

	}

	/*
	 * Copy constructor is forbidden for LttngEvenmStream
	 */
	public LTTngTrace(LTTngTrace oldTrace) throws Exception {
		this(oldTrace.getPath(),oldTrace.getTraceLibPath(), false, true);

		// *** VERIFY ***
		// Is this safe?
		this.fCheckpoints = oldTrace.fCheckpoints;

		/*
		 * // This would only work if the index is already done
		 * this.fCheckpoints = new Vector<TmfCheckpoint>(
		 * oldTrace.fCheckpoints.size() ); for (int x = 0;
		 * x<oldTrace.fCheckpoints.size(); x++){ TmfCheckpoint tmpCheckPoint =
		 * oldTrace.fCheckpoints.get(x); this.fCheckpoints.add( new
		 * TmfCheckpoint(tmpCheckPoint.getTimestamp(),
		 * tmpCheckPoint.getLocation()) ); }
		 */

		// Set the start time of the trace
		setTimeRange(new TmfTimeRange(new LttngTimestamp(
				oldTrace.getStartTime()), new LttngTimestamp(
				oldTrace.getEndTime())));
	}

	
    
    @Override
	public LTTngTrace createTraceCopy() { 
    	LTTngTrace returnedTrace = null;
    	
    	try {
    		returnedTrace = new LTTngTrace(this);
    	}
    	catch (Exception e) {
    		System.out.println("ERROR : Could not create LTTngTrace copy (createTraceCopy).\nError is : " + e.getStackTrace()); //$NON-NLS-1$
    	}
    	
    	return returnedTrace;
    }
    
    @Override
    public synchronized LTTngTrace clone() {
    	LTTngTrace clone = null;
    	try {
    		clone = (LTTngTrace) super.clone();
       		try {
				clone.currentJniTrace = JniTraceFactory.getJniTrace(getPath(),getTraceLibPath(), SHOW_LTT_DEBUG_DEFAULT);
			} catch (JniException e) {
				// e.printStackTrace();
			}

			// Export all the event types from the JNI side
			clone.traceTypes = new HashMap<Integer, LttngEventType>();
			clone.traceTypeNames = new Vector<Integer>();
			clone.initialiseEventTypes(clone.currentJniTrace);

			// Verify that all those "default constructor" are safe to use
			clone.eventTimestamp = new LttngTimestamp();
			clone.eventSource = new LttngEventSource();
			clone.eventType = new LttngEventType();
			clone.eventContent = new LttngEventContent(clone.currentLttngEvent);
			clone.eventReference = new LttngEventReference(this.getName());

			// Create the skeleton event
			clone.currentLttngEvent = new LttngEvent(this,
					clone.eventTimestamp, clone.eventSource, clone.eventType,
					clone.eventContent, clone.eventReference, null);

			// Create a new current location
			clone.previousLocation = new LttngLocation();

			// Set the currentEvent to the eventContent
			clone.eventContent.setEvent(clone.currentLttngEvent);

			// Set the start time of the trace
			setTimeRange(new TmfTimeRange(new LttngTimestamp(
					clone.currentJniTrace.getStartTime().getTime()),
					new LttngTimestamp(clone.currentJniTrace.getEndTime()
							.getTime())));
		} catch (CloneNotSupportedException e) {
		}

		return clone;
	}

	public String getTraceLibPath() {
		return traceLibPath;
	}

	/*
	 * Fill out the HashMap with "Type" (Tracefile/Marker)
	 * 
	 * This should be called at construction once the trace is open
	 */
	private void initialiseEventTypes(JniTrace trace) {
		// Work variables
		LttngEventType tmpType = null;
		String[] markerFieldsLabels = null;

		String newTracefileKey = null;
		Integer newMarkerKey = null;

		JniTracefile newTracefile = null;
		JniMarker newMarker = null;

		// First, obtain an iterator on TRACEFILES of owned by the TRACE
		Iterator<String> tracefileItr = trace.getTracefilesMap().keySet()
				.iterator();

		while (tracefileItr.hasNext()) {
			newTracefileKey = tracefileItr.next();
			newTracefile = trace.getTracefilesMap().get(newTracefileKey);

			// From the TRACEFILE read, obtain its MARKER
			Iterator<Integer> markerItr = newTracefile.getTracefileMarkersMap()
					.keySet().iterator();
			while (markerItr.hasNext()) {
				newMarkerKey = markerItr.next();
				newMarker = newTracefile.getTracefileMarkersMap().get(
						newMarkerKey);

				// From the MARKER we can obtain the MARKERFIELDS keys (i.e.
				// labels)
				markerFieldsLabels = newMarker
						.getMarkerFieldsHashMap()
						.keySet()
						.toArray(
								new String[newMarker.getMarkerFieldsHashMap()
										.size()]);
 
				tmpType = new LttngEventType(newTracefile.getTracefileName(),
						newTracefile.getCpuNumber(), newMarker.getName(), 
						newMarkerKey.intValue(), markerFieldsLabels);

				// Add the type to the map/vector
				addEventTypeToMap(tmpType);
			}
		}
	}

	/*
	 * Add a new type to the HashMap
	 * 
	 * As the hashmap use a key format that is a bit dangerous to use, we should
	 * always add using this function.
	 */
	private void addEventTypeToMap(LttngEventType newEventType) {
		int newTypeKey = EventTypeKey.getEventTypeHash(newEventType);

		this.traceTypes.put(newTypeKey, newEventType);
		this.traceTypeNames.add(newTypeKey);
	}

	// /**
	// * Index the current trace.
	// *
	// * @param useless This boolean is only to comply to the interface and will
	// be ignored.
	// */
	// @Override
	// public synchronized void indexTrace(boolean useless) {
	//
	// long nbEvents=0L;
	//
	// // Start time need to be null to detect none have been set
	// // LastTime need to exist so we can ajust it as we go
	// LttngTimestamp startTime = null;
	// LttngTimestamp lastTime = new LttngTimestamp();
	//
	// // Position the trace at the beginning
	// TmfContext context = seekEvent( new LttngTimestamp(0L) );
	//
	// // Read the first event and extract the location
	// LttngEvent tmpEvent = (LttngEvent)getNextEvent(context);
	//
	// // If we read the first event, define the start time.
	// if ( tmpEvent != null ) {
	// startTime = new LttngTimestamp( tmpEvent.getTimestamp() );
	// lastTime.setValue(tmpEvent.getTimestamp().getValue());
	// }
	//
	// // Now, we read each event until we hit the end of the trace
	// // We will create a new checkpoint every "getCacheSize()" event
	// while ( tmpEvent != null) {
	// // Update the last time each time we read a new event
	// lastTime.setValue(tmpEvent.getTimestamp().getValue());
	//
	// // Save a check point if needed
	// if ((nbEvents++ % getCacheSize()) == 0) {
	// // *** IMPORTANT
	// // We need to NEW each stuff we put in checkpoint
	// // Otherwise everything will be the same!
	// LttngTimestamp tmpTimestamp = new LttngTimestamp(
	// (LttngTimestamp)tmpEvent.getTimestamp() );
	// LttngLocation newLocation = new LttngLocation(
	// (LttngTimestamp)tmpEvent.getTimestamp() );
	//
	// fCheckpoints.add(new TmfCheckpoint(tmpTimestamp, newLocation ) );
	// }
	// // Read the next event
	// tmpEvent = (LttngEvent)getNextEvent(context);
	// }
	//
	// // If we have a start time, we should have an end time as well
	// // Issue the new range
	// if (startTime != null) {
	// setTimeRange( new TmfTimeRange(startTime, lastTime) );
	// notifyListeners(getTimeRange() );
	// }
	//
	// // Ajust the total number of event in the trace
	// fNbEvents = nbEvents;
	// //printCheckpointsVector();
	// //printDebug = true;
	// }

	/**
	 * Return the latest saved location. Note : Modifying the returned location
	 * may result in buggy positionning!
	 * 
	 * @return The LttngLocation as it was after the last operation.
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngLocation
	 */
	@Override
	public synchronized ITmfLocation<?> getCurrentLocation() {
		return previousLocation;
	}

	/**
	 * Position the trace to the event at the given location.
	 * <p>
	 * NOTE : Seeking by location is very fast compare to seeking by position
	 * but is still slower than "ReadNext", avoid using it for small interval.
	 * 
	 * @param location
	 *            Location of the event in the trace. If no event available at
	 *            this exact location, we will position ourself to the next one.
	 * 
	 * @return The TmfContext that point to this event
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngLocation
	 * @see org.eclipse.linuxtools.tmf.trace.TmfContext
	 */
	@Override
	public synchronized TmfContext seekLocation(ITmfLocation<?> location) {

		// // [lmcfrch]
		// lastTime = 0;

		if (PrintDebug) {
			System.out
					.println("seekLocation(location) location -> " + location); //$NON-NLS-1$
		}

		// If the location in context is null, create a new one
		LttngLocation curLocation = null;
		if (location == null) {
			curLocation = new LttngLocation();
			TmfContext context = seekEvent(curLocation.getOperationTime());
			context.setRank(ITmfContext.INITIAL_RANK);
			return context;
		} else {
			curLocation = (LttngLocation) location;
		}

		// *** NOTE :
		// Update to location should (and will) be done in SeekEvent.

		// The only seek valid in LTTng is with the time, we call
		// seekEvent(timestamp)
		TmfContext context = seekEvent(curLocation.getOperationTime());

		// // Adjust the previousLocation flags
		// if (location instanceof LttngLocation) {
		// LttngLocation lttngLocation = (LttngLocation) location;
		// if (lttngLocation.isLastOperationReadNext()) {
		// previousLocation.setLastOperationReadNext();
		// } else if (lttngLocation.isLastOperationParse()) {
		// previousLocation.setLastOperationParse();
		// } else if (lttngLocation.isLastOperationSeek()) {
		// previousLocation.setLastOperationSeek();
		// }
		// }

		return context;
	}

	/**
	 * Position the trace to the event at the given time.
	 * <p>
	 * NOTE : Seeking by time is very fast compare to seeking by position but is
	 * still slower than "ReadNext", avoid using it for small interval.
	 * 
	 * @param timestamp
	 *            Time of the event in the trace. If no event available at this
	 *            exact time, we will position ourself to the next one.
	 * 
	 * @return The TmfContext that point to this event
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngLocation
	 * @see org.eclipse.linuxtools.tmf.trace.TmfContext
	 */
	@Override
	public synchronized TmfContext seekEvent(TmfTimestamp timestamp) {

		// // [lmcfrch]
		// lastTime = 0;

		if (PrintDebug) {
			System.out
					.println("seekEvent(timestamp) timestamp -> " + timestamp); //$NON-NLS-1$
		}

		// Call JNI to seek
		currentJniTrace.seekToTime(new JniTime(timestamp.getValue()));

		// Save the time at which we seeked
		previousLocation.setOperationTime(timestamp.getValue());
		// Set the operation marker as seek, to be able to detect we did "seek"
		// this event
		previousLocation.setLastOperationSeek();

		// *** VERIFY ***
		// Is that too paranoid?
		//
		// We don't trust what upper level could do with our internal location
		// so we create a new one to return instead
		LttngLocation curLocation = new LttngLocation(previousLocation);

		return new TmfContext(curLocation);
	}

	/**
	 * Position the trace to the event at the given position (rank).
	 * <p>
	 * NOTE : Seeking by position is very slow in LTTng, consider seeking by
	 * timestamp.
	 * 
	 * @param position
	 *            Position (or rank) of the event in the trace, starting at 0.
	 * 
	 * @return The TmfContext that point to this event
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngLocation
	 * @see org.eclipse.linuxtools.tmf.trace.TmfContext
	 */
	@Override
	public synchronized TmfContext seekEvent(long position) {

		if (PrintDebug) {
			System.out.println("seekEvent(position) position -> " + position); //$NON-NLS-1$
		}

		TmfTimestamp timestamp = null;
		long index = position / getCacheSize();

		// Get the timestamp of the closest check point to the given position
		if (fCheckpoints.size() > 0) {
			if (index >= fCheckpoints.size()) {
				index = fCheckpoints.size() - 1;
			}
			timestamp = fCheckpoints.elementAt((int) index)
					.getTimestamp();
		}
		// If none, take the start time of the trace
		else {
			timestamp = getStartTime();
		}

		// Seek to the found time
		TmfContext tmpContext = seekEvent(timestamp);
		tmpContext.setRank((index + 1) * fIndexPageSize);
		previousLocation = (LttngLocation) tmpContext.getLocation();

		// Ajust the index of the event we found at this check point position
		Long currentPosition = index * getCacheSize();

		Long lastTimeValueRead = 0L;

		// Get the event at current position. This won't move to the next one
		JniEvent tmpJniEvent = currentJniTrace.findNextEvent();
		// Now that we are positionned at the checkpoint,
		// we need to "readNext" (Position - CheckpointPosition) times or until
		// trace "run out"
		while ((tmpJniEvent != null) && (currentPosition < position)) {
			tmpJniEvent = currentJniTrace.readNextEvent();
			currentPosition++;
		}

		// If we found our event, save its timestamp
		if (tmpJniEvent != null) {
			lastTimeValueRead = tmpJniEvent.getEventTime().getTime();
		}

		// Set the operation marker as seek, to be able to detect we did "seek"
		// this event
		previousLocation.setLastOperationSeek();
		// Save read event time
		previousLocation.setOperationTime(lastTimeValueRead);

		// *** VERIFY ***
		// Is that too paranoid?
		//
		// We don't trust what upper level could do with our internal location
		// so we create a new one to return instead
		LttngLocation curLocation = new LttngLocation(previousLocation);

		return new TmfContext(curLocation);
	}

	@Override
	public TmfContext seekLocation(double ratio) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public double getLocationRatio(ITmfLocation<?> location) {
		// TODO Auto-generated method stub
		return 0;
	}

	/**
	 * Return the event in the trace according to the given context. Read it if
	 * necessary.
	 * <p>
	 * Similar (same?) as ParseEvent except that calling GetNext twice read the
	 * next one the second time.
	 * 
	 * @param context
	 *            Current TmfContext where to get the event
	 * 
	 * @return The LttngEvent we read of null if no event are available
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngLocation
	 * @see org.eclipse.linuxtools.tmf.trace.TmfContext
	 */

	public int nbEventsRead = 0;

	@Override
	public synchronized LttngEvent getNextEvent(TmfContext context) {

		if (PrintDebug) {
			System.out
					.println("getNextEvent(context) context.getLocation() -> " //$NON-NLS-1$
							+ context.getLocation());
		}

		LttngEvent returnedEvent = null;
		LttngLocation curLocation = null;

		curLocation = (LttngLocation)context.getLocation();
    	// If the location in context is null, create a new one
    	if ( curLocation == null ) {
    		curLocation = getCurrentLocation(context);
    	}

		// // [lmcfrch]
		// TmfContext savedContext = context.clone();
		// // [/lmcfrch]

		// *** HACK ***
		// TMF assumes it is possible to read (GetNextEvent) to the next Event
		// once ParseEvent() is called
		// In LTTNG, there is not difference between "Parsing" and "Reading" an
		// event.
		// Since parsing/reading invalidate the previous event,
		// we need to make sure the sequence ParseEvent() -> GetNextEvent() will
		// not actually move to the next event.
		// To do so, we avoid moving for call to "GetNextEvent()" that follow
		// call to a call to "ParseEvent()".
		// However, calling ParseEvent() -> GetNextEvent() -> GetNextEvent()
		// will only move next by one.

		// *** Positioning trick :
		// GetNextEvent only read the trace if :
		// 1- The last operation was NOT a ParseEvent --> A read is required
		// OR
		// 2- The time of the previous location is different from the current
		// one --> A seek + a read is required
		if ((!(curLocation.isLastOperationParse()))
				|| (previousLocation.getOperationTimeValue() != curLocation
						.getOperationTimeValue())) {
			if (previousLocation.getOperationTimeValue() != curLocation
					.getOperationTimeValue()) {
				if (PrintDebug) {
					System.out
							.println("\t\tSeeking in getNextEvent. [ LastTime : " //$NON-NLS-1$
									+ previousLocation.getOperationTimeValue()
									+ " CurrentTime" //$NON-NLS-1$
									+ curLocation.getOperationTimeValue()
									+ " ]"); //$NON-NLS-1$
				}
				seekEvent(curLocation.getOperationTime());
			}
			// Read the next event from the trace. The last one will NO LONGER
			// BE VALID.
			returnedEvent = readNextEvent(curLocation);
			
		} else {
			// No event was read, just return the one currently loaded (the last
			// one we read)
			returnedEvent = currentLttngEvent;

			// *** IMPORTANT!
			// Reset (erase) the operation marker to both location, to be able
			// to detect we did NOT "read" this event
			previousLocation.resetLocationState();
			curLocation.resetLocationState();
		}

		// If we read an event, set it's time to the locations (both previous
		// and current)
		if (returnedEvent != null) {
			setPreviousAndCurrentTimes(context, returnedEvent, curLocation);

			// // [lmcfrch]
			// LttngLocation prevLocation = (LttngLocation)
			// savedContext.getLocation();
			// LttngLocation currLocation = (LttngLocation)
			// context.getLocation();
			// if (prevLocation.equals(currLocation)) {
			// System.out.println("Aie");
			// }
			// Tracer.trace("Trc: " + context.getRank() + ": " +
			// returnedEvent.getTimestamp().toString() + " (" +
			// (prevLocation.isLastOperationParse() ? "T" : "F") + "," +
			// (prevLocation.isLastOperationReadNext() ? "T" : "F") + "," +
			// (prevLocation.isLastOperationSeek() ? "T" : "F") + "), (" +
			// (currLocation.isLastOperationParse() ? "T" : "F") + "," +
			// (currLocation.isLastOperationReadNext() ? "T" : "F") + "," +
			// (currLocation.isLastOperationSeek() ? "T" : "F") + ")"
			// );
			// // [/lmcfrch]

		
		}

		return returnedEvent;
	}

	// this method was extracted for profiling purposes
	private void setPreviousAndCurrentTimes(TmfContext context, LttngEvent returnedEvent,
			LttngLocation curLocation) {
		
		TmfTimestamp eventTimestamp = returnedEvent.getTimestamp();
		//long eventTime = eventTimestamp.getValue();
		previousLocation.setOperationTime(eventTimestamp.getValue());
		curLocation.setOperationTime(eventTimestamp.getValue());
		updateIndex(context, context.getRank(), eventTimestamp);
		context.updateRank(1);
	}

	protected void updateIndex(TmfContext context, long rank, TmfTimestamp timestamp) {
		
		if (getStartTime().compareTo(timestamp, false) > 0) setStartTime( timestamp );
		if (getEndTime().compareTo(timestamp, false) < 0) setEndTime(timestamp );
		if (rank != ITmfContext.UNKNOWN_RANK) {
			if (fNbEvents <= rank)
				fNbEvents = rank + 1;
			// Build the index as we go along
			if ((rank % fIndexPageSize) == 0) {
				// Determine the table position
				long position = rank / fIndexPageSize;
				// Add new entry at proper location (if empty) 
				if (fCheckpoints.size() == position) {
					addCheckPoint(context, timestamp);
				}
			}
		}
	}

	private void addCheckPoint(TmfContext context, TmfTimestamp timestamp) {
		ITmfLocation<?> location = context.getLocation().clone();
		fCheckpoints.add(new TmfCheckpoint(timestamp.clone(), location));
	}
	
	// this method was extracted for profiling purposes
	private LttngEvent readNextEvent(LttngLocation curLocation) {
		LttngEvent returnedEvent;
		// Read the next event from the trace. The last one will NO LONGER BE VALID.
		returnedEvent = readEvent(curLocation);
		nbEventsRead++;
		
		// Set the operation marker as read to both location, to be able to detect we did "read" this event
		previousLocation.setLastOperationReadNext();
		curLocation.setLastOperationReadNext();
		return returnedEvent;
	}
	
	// this method was extracted for profiling purposes
	private LttngLocation getCurrentLocation(TmfContext context) {
		LttngLocation curLocation;
		curLocation = new LttngLocation();
		context.setLocation(curLocation);
		return curLocation;
	}
	/**
	 * Return the event in the trace according to the given context. Read it if
	 * necessary.
	 * <p>
	 * Similar (same?) as GetNextEvent except that calling ParseEvent twice will
	 * return the same event
	 * 
	 * @param context
	 *            Current TmfContext where to get the event
	 * 
	 * @return The LttngEvent we read of null if no event are available
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngLocation
	 * @see org.eclipse.linuxtools.tmf.trace.TmfContext
	 */
	@Override
	public synchronized LttngEvent parseEvent(TmfContext context) {

		if (PrintDebug) {
			System.out.println("parseEvent(context) context.getLocation() -> " //$NON-NLS-1$
					+ context.getLocation());
		}

		LttngEvent returnedEvent = null;
		LttngLocation curLocation = null;

		// If the location in context is null, create a new one
		if (context.getLocation() == null) {
			curLocation = new LttngLocation();
			context.setLocation(curLocation);
		}
		// Otherwise, we use the one in context; it should be a valid
		// LttngLocation
		else {
			curLocation = (LttngLocation) context.getLocation();
		}

		// *** HACK ***
		// TMF assumes it is possible to read (GetNextEvent) to the next Event
		// once ParseEvent() is called
		// In LTTNG, there is not difference between "Parsing" and "Reading" an
		// event.
		// So, before "Parsing" an event, we have to make sure we didn't "Read"
		// it alreafy.
		// Also, "Reading" invalidate the previous Event in LTTNG and seek back
		// is very costly,
		// so calling twice "Parse" will return the same event, giving a way to
		// get the "Currently loaded" event

		// *** Positionning trick :
		// ParseEvent only read the trace if :
		// 1- The last operation was NOT a ParseEvent or a GetNextEvent --> A
		// read is required
		// OR
		// 2- The time of the previous location is different from the current
		// one --> A seek + a read is required
		if (((!(curLocation.isLastOperationParse())) && ((!(curLocation
				.isLastOperationReadNext()))))
				|| (previousLocation.getOperationTimeValue() != curLocation
						.getOperationTimeValue())) {
			// Previous time != Current time : We need to reposition to the
			// current time
			if (previousLocation.getOperationTimeValue() != curLocation
					.getOperationTimeValue()) {
				if (PrintDebug) {
					System.out
							.println("\t\tSeeking in getNextEvent. [ LastTime : " //$NON-NLS-1$
									+ previousLocation.getOperationTimeValue()
									+ " CurrentTime" //$NON-NLS-1$
									+ curLocation.getOperationTimeValue()
									+ " ]"); //$NON-NLS-1$
				}
				seekEvent(curLocation.getOperationTime());
			}

			// Read the next event from the trace. The last one will NO LONGER
			// BE VALID.
			returnedEvent = readEvent(curLocation);
		} else {
			// No event was read, just return the one currently loaded (the last
			// one we read)
			returnedEvent = currentLttngEvent;
		}

		// If we read an event, set it's time to the locations (both previous
		// and current)
		if (returnedEvent != null) {
			previousLocation.setOperationTime((LttngTimestamp) returnedEvent
					.getTimestamp());
			curLocation.setOperationTime((LttngTimestamp) returnedEvent
					.getTimestamp());
		}

		// Set the operation marker as parse to both location, to be able to
		// detect we already "read" this event
		previousLocation.setLastOperationParse();
		curLocation.setLastOperationParse();

		return returnedEvent;
	}

	/*
	 * Read the next event from the JNI and convert it as Lttng Event<p>
	 * 
	 * @param location Current LttngLocation that to be updated with the event
	 * timestamp
	 * 
	 * @return The LttngEvent we read of null if no event are available
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngLocation
	 * 
	 * @see org.eclipse.linuxtools.org.eclipse.linuxtools.lttng.jni.JniTrace
	 */
	private synchronized LttngEvent readEvent(LttngLocation location) {
		LttngEvent returnedEvent = null;
		JniEvent tmpEvent = null;

		// Read the next event from JNI. THIS WILL INVALIDATE THE CURRENT LTTNG
		// EVENT.
		tmpEvent = currentJniTrace.readNextEvent();

		if (tmpEvent != null) {
			// *** NOTE
			// Convert will update the currentLttngEvent
			returnedEvent = convertJniEventToTmf(tmpEvent);

			location.setOperationTime((LttngTimestamp) returnedEvent
					.getTimestamp());
		}
		// *** NOTE
		// If the read failed (likely the last event in the trace), set the
		// LastReadTime to the JNI time
		// That way, even if we try to read again, we will step over the bogus
		// seek and read
		else {
			location.setOperationTime(getEndTime().getValue() + 1);
		}

		return returnedEvent;
	}

	/**
	 * Method to convert a JniEvent into a LttngEvent.
	 * <p>
	 * 
	 * Note : This method will call LttngEvent convertEventJniToTmf(JniEvent,
	 * boolean) with a default value for isParsingNeeded
	 * 
	 * @param newEvent
	 *            The JniEvent to convert into LttngEvent
	 * 
	 * @return The converted LttngEvent
	 * 
	 * @see org.eclipse.linuxtools.org.eclipse.linuxtools.lttng.jni.JniEvent
	 * @see org.eclipse.linuxtools.lttng.event.LttngEvent
	 */
	public synchronized LttngEvent convertJniEventToTmf(JniEvent newEvent) {
		currentLttngEvent = convertJniEventToTmf(newEvent,
				IS_PARSING_NEEDED_DEFAULT);

		return currentLttngEvent;
	}

	/**
	 * Method to convert a JniEvent into a LttngEvent
	 * 
	 * @param jniEvent
	 *            The JniEvent to convert into LttngEvent
	 * @param isParsingNeeded
	 *            A boolean value telling if the event should be parsed or not.
	 * 
	 * @return The converted LttngEvent
	 * 
	 * @see org.eclipse.linuxtools.org.eclipse.linuxtools.lttng.jni.JniEvent
	 * @see org.eclipse.linuxtools.lttng.event.LttngEvent
	 */
	public synchronized LttngEvent convertJniEventToTmf(JniEvent jniEvent,
			boolean isParsingNeeded) {

		if (UniqueEvent) {

			// ***
			// UNHACKED : We can no longer do that because TCF need to maintain
			// several events at once.
			// This is very slow to do so in LTTng, this has to be temporary.
			// *** HACK ***
			// To save time here, we only set value instead of allocating new
			// object
			// This give an HUGE performance improvement
			// all allocation done in the LttngTrace constructor
			// ***
			eventTimestamp.setValue(jniEvent.getEventTime().getTime());
			eventSource.setSourceId(jniEvent.requestEventSource());

			eventType = traceTypes.get(EventTypeKey.getEventTypeHash(jniEvent));

			eventReference.setValue(jniEvent.getParentTracefile()
					.getTracefilePath());
			eventReference.setTracepath(this.getName());

			eventContent.emptyContent();

			currentLttngEvent.setType(eventType);
			// Save the jni reference
			currentLttngEvent.updateJniEventReference(jniEvent);

			// Parse now if was asked
			// Warning : THIS IS SLOW
			if (isParsingNeeded) {
				eventContent.getFields();
			}

			return currentLttngEvent;
		} else {
			return convertJniEventToTmfMultipleEventEvilFix(jniEvent,
					isParsingNeeded);
		}

	}

	/**
	 * This method is a temporary fix to support multiple events at once in TMF
	 * This is expected to be slow and should be fixed in another way. See
	 * comment in convertJniEventToTmf();
	 * 
	 * @param jniEvent
	 *            The current JNI Event
	 * @return Current Lttng Event fully parsed
	 */
	private synchronized LttngEvent convertJniEventToTmfMultipleEventEvilFix(
			JniEvent jniEvent, boolean isParsingNeeded) {
		// *** HACK ***
		// Below : the "fix" with all the new and the full-parse
		// Allocating new memory is slow.
		// Parsing every events is very slow.
		eventTimestamp = new LttngTimestamp(jniEvent.getEventTime().getTime());
		eventSource = new LttngEventSource(jniEvent.requestEventSource());
		eventReference = new LttngEventReference(jniEvent.getParentTracefile()
				.getTracefilePath(), this.getName());
		eventType = new LttngEventType(traceTypes.get(EventTypeKey
				.getEventTypeHash(jniEvent)));
		eventContent = new LttngEventContent(currentLttngEvent);
		currentLttngEvent = new LttngEvent(this, eventTimestamp, eventSource,
				eventType, eventContent, eventReference, null);

		// The jni reference is no longer reliable but we will keep it anyhow
		currentLttngEvent.updateJniEventReference(jniEvent);
		// Ensure that the content is correctly set
		eventContent.setEvent(currentLttngEvent);

		// Parse the event if it was needed
		// *** WARNING ***
		// ONLY for testing, NOT parsing events with non-unique events WILL
		// result in segfault in the JVM
		if (isParsingNeeded) {
			eventContent.getFields();
		}

		return currentLttngEvent;
	}

	/**
	 * Reference to the current LttngTrace we are reading from.
	 * <p>
	 * 
	 * Note : This bypass the framework and should not be use, except for
	 * testing!
	 * 
	 * @return Reference to the current LttngTrace
	 * 
	 * @see org.eclipse.linuxtools.org.eclipse.linuxtools.lttng.jni.JniTrace
	 */
	public JniTrace getCurrentJniTrace() {
		return currentJniTrace;
	}

	/**
	 * Return a reference to the current LttngEvent we have in memory.
	 * 
	 * @return The current (last read) LttngEvent
	 * 
	 * @see org.eclipse.linuxtools.lttng.event.LttngEvent
	 */
	public synchronized LttngEvent getCurrentEvent() {
		return currentLttngEvent;
	}

	/**
	 * Get the major version number for the current trace
	 * 
	 * @return Version major or -1 if unknown
	 * 
	 * @see org.eclipse.linuxtools.org.eclipse.linuxtools.lttng.jni.JniTrace
	 * 
	 */
	public short getVersionMajor() {
		if (currentJniTrace != null) {
			return currentJniTrace.getLttMajorVersion();
		} else {
			return -1;
		}
	}

	/**
	 * Get the minor version number for the current trace
	 * 
	 * @return Version minor or -1 if unknown
	 * 
	 * @see org.eclipse.linuxtools.org.eclipse.linuxtools.lttng.jni.JniTrace
	 * 
	 */
	public short getVersionMinor() {
		if (currentJniTrace != null) {
			return currentJniTrace.getLttMinorVersion();
		} else {
			return -1;
		}
	}

	/**
	 * Get the number of CPU for this trace
	 * 
	 * @return Number of CPU or -1 if unknown
	 * 
	 * @see org.eclipse.linuxtools.org.eclipse.linuxtools.lttng.jni.JniTrace
	 * 
	 */
	public int getCpuNumber() {
		if (currentJniTrace != null) {
			return currentJniTrace.getCpuNumber();
		} else {
			return -1;
		}
	}

	/**
	 * Print the content of the checkpoint vector.
	 * <p>
	 * 
	 * This is intended for debug purpose only.
	 */
	public void printCheckpointsVector() {
		System.out.println("StartTime : " //$NON-NLS-1$
				+ getTimeRange().getStartTime().getValue());
		System.out.println("EndTime   : " //$NON-NLS-1$
				+ getTimeRange().getEndTime().getValue());

		for (int pos = 0; pos < fCheckpoints.size(); pos++) {
			System.out.print(pos + ": " + "\t"); //$NON-NLS-1$ //$NON-NLS-2$
			System.out.print(fCheckpoints.get(pos).getTimestamp() + "\t"); //$NON-NLS-1$
			System.out.println(fCheckpoints.get(pos).getLocation());
		}
	}

	@Override
	public synchronized void dispose() {
		currentJniTrace.closeTrace();
		super.dispose();
	}

	/**
	 * Return a String identifying this trace.
	 * 
	 * @return String that identify this trace
	 */
	@Override
    @SuppressWarnings("nls")
	public String toString() {
		String returnedData = "";

		returnedData += "Path :" + getPath() + " ";
		returnedData += "Trace:" + currentJniTrace + " ";
		returnedData += "Event:" + currentLttngEvent;

		return returnedData;
	}

}

/*
 * EventTypeKey inner class
 * 
 * This class is used to make the process of generating the HashMap key more
 * transparent and so less error prone to use
 */
final class EventTypeKey {
	// *** WARNING ***
	// These two getEventTypeKey() functions should ALWAYS construct the key the
	// same ways!
	// Otherwise, every type search will fail!

	// added final to encourage inlining. 
	
	// generating a hash code by hand to avoid a string creation
	final static public int getEventTypeHash( LttngEventType newEventType )
	{
		return generateHash(newEventType.getTracefileName(), newEventType.getCpuId(), newEventType.getMarkerName() );
	}

	final private static int generateHash(String traceFileName, long cpuNumber , String markerName) {
		// 0x1337 is a prime number. The number of CPUs is always under 8192 on the current kernel, so this will work with the current linux kernel.
		int cpuHash = (int) (cpuNumber*(0x1337));
		return traceFileName.hashCode() ^(cpuHash)  ^ markerName.hashCode();
	}

	// generating a hash code by hand to avoid a string creation
	final static public int getEventTypeHash( JniEvent newEvent )
	{
		return generateHash( newEvent.getParentTracefile().getTracefileName(), newEvent.getParentTracefile().getCpuNumber(),newEvent.requestEventMarker().getName() );
	}


}