org.eclipse.mylyn.monitor.usage/src/org/eclipse/mylyn/internal/monitor/usage/InteractionEventLogger.java - mylyn/org.eclipse.mylyn.incubator - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004, 2009 Tasktop Technologies and others.
  * 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:
  *     Tasktop Technologies - initial API and implementation
  *     Ken Sueda - XML serialization
  *******************************************************************************/

 package org.eclipse.mylyn.internal.monitor.usage;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
 import java.io.StringReader;
 import java.text.DateFormat;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;

 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.mylyn.commons.core.StatusHandler;
 import org.eclipse.mylyn.commons.net.HtmlStreamTokenizer;
 import org.eclipse.mylyn.commons.net.HtmlStreamTokenizer.Token;
 import org.eclipse.mylyn.internal.context.core.InteractionContextExternalizer;
 import org.eclipse.mylyn.monitor.core.AbstractMonitorLog;
 import org.eclipse.mylyn.monitor.core.IInteractionEventListener;
 import org.eclipse.mylyn.monitor.core.InteractionEvent;
 import org.eclipse.mylyn.monitor.core.InteractionEvent.Kind;

 /**
  * @author Mik Kersten TODO: use buffered output stream for better performance?
  */
 public class InteractionEventLogger extends AbstractMonitorLog implements IInteractionEventListener {

 	private int eventAccumulartor = 0;

 	private final List<InteractionEvent> queue = new CopyOnWriteArrayList<InteractionEvent>();

 	private final InteractionEventObfuscator handleObfuscator = new InteractionEventObfuscator();

 	private static final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S z", Locale.ENGLISH); //$NON-NLS-1$

 	public InteractionEventLogger(File outputFile) {
 		this.outputFile = outputFile;
 	}

 	public synchronized void interactionObserved(InteractionEvent event) {
 //		System.err.println("> " + event); //$NON-NLS-1$
 		if (UiUsageMonitorPlugin.getDefault() == null) {
 			StatusHandler.log(new Status(IStatus.WARNING, UiUsageMonitorPlugin.ID_PLUGIN,
 					"Attempted to log event before usage monitor start")); //$NON-NLS-1$
 		}
 		if (UiUsageMonitorPlugin.getDefault().isObfuscationEnabled()) {
 			String obfuscatedHandle = handleObfuscator.obfuscateHandle(event.getStructureKind(),
 					event.getStructureHandle());
 			event = new InteractionEvent(event.getKind(), event.getStructureKind(), obfuscatedHandle,
 					event.getOriginId(), event.getNavigation(), event.getDelta(), event.getInterestContribution());
 		}
 		try {
 			if (started) {
 				String xml = getXmlForEvent(event);
 				if (outputStream != null) {
 					outputStream.write(xml.getBytes());
 				}
 			} else if (event != null) {
 				queue.add(event);
 			}
 			eventAccumulartor++;
 		} catch (Throwable t) {
 			StatusHandler.log(new Status(IStatus.WARNING, UiUsageMonitorPlugin.ID_PLUGIN,
 					"Could not log interaction event", t)); //$NON-NLS-1$
 		}
 	}

 	@Override
 	public void startMonitoring() {
 		super.startMonitoring();
 		for (InteractionEvent queuedEvent : queue) {
 			interactionObserved(queuedEvent);
 		}
 		queue.clear();
 	}

 	@Override
 	public void stopMonitoring() {
 		super.stopMonitoring();
 		if (UiUsageMonitorPlugin.getDefault() != null) {
 			UiUsageMonitorPlugin.getDefault().incrementObservedEvents(eventAccumulartor);
 		}
 		eventAccumulartor = 0;
 	}

 	private String getXmlForEvent(InteractionEvent event) {
 		return writeLegacyEvent(event);
 	}

 	/**
 	 * @return true if successfully cleared
 	 */
 	public synchronized void clearInteractionHistory() throws IOException {
 		this.clearInteractionHistory(true);
 	}

 	public synchronized void clearInteractionHistory(boolean startMonitoring) throws IOException {
 		stopMonitoring();
 		outputStream = new FileOutputStream(outputFile, false);
 		outputStream.flush();
 		outputStream.close();
 		outputFile.delete();
 		outputFile.createNewFile();
 		if (startMonitoring) {
 			startMonitoring();
 		}
 	}

 	public List<InteractionEvent> getHistoryFromFile(File file) {
 		return getHistoryFromFile(file, new NullProgressMonitor());
 	}

 	public List<InteractionEvent> getHistoryFromFile(File file, IProgressMonitor monitor) {

 		List<InteractionEvent> events = new ArrayList<InteractionEvent>();
 		InputStream inputStream = null;
 		long fileLength = 0;

 		ZipFile zip = null;
 		try {
 			// The file may be a zip file...
 			if (file.getName().endsWith(".zip")) { //$NON-NLS-1$
 				zip = new ZipFile(file);
 				if (zip.entries().hasMoreElements()) {
 					ZipEntry entry = zip.entries().nextElement();
 					inputStream = zip.getInputStream(entry);
 					fileLength = entry.getSize();
 				}
 			} else {
 				inputStream = new FileInputStream(file);
 				fileLength = file.length();
 			}

 			//450: the approximate size of an event in XML
 			int numberOfEventsEstimate = (int) (fileLength / 450);

 			monitor.beginTask(Messages.InteractionEventLogger_Reading_History_From_File, numberOfEventsEstimate);

 			getHistoryFromStream(inputStream, events, monitor);

 		} catch (Exception e) {
 			StatusHandler.log(new Status(IStatus.ERROR, UiUsageMonitorPlugin.ID_PLUGIN,
 					"Could not read interaction history", e)); //$NON-NLS-1$
 		} finally {
 			if (inputStream != null) {
 				try {
 					inputStream.close();
 				} catch (IOException e) {
 					StatusHandler.log(new Status(IStatus.ERROR, UiUsageMonitorPlugin.ID_PLUGIN,
 							"unable to close input stream", e)); //$NON-NLS-1$
 				}
 			}
 			if (zip != null) {
 				try {
 					zip.close();
 				} catch (IOException e) {
 					// ignore
 				}
 			}
 		}

 		monitor.done();

 		return events;
 	}

 	/**
 	 * @param events
 	 * @param monitor
 	 * @param tag
 	 * @param endl
 	 * @param buf
 	 */
 	private void getHistoryFromStream(InputStream reader, List<InteractionEvent> events, IProgressMonitor monitor)
 			throws IOException {
 		String xml;
 		int index;
 		String buf = ""; //$NON-NLS-1$
 		String tag = "</" + InteractionContextExternalizer.ELMNT_INTERACTION_HISTORY_OLD + ">"; //$NON-NLS-1$ //$NON-NLS-2$
 		String endl = "\r\n"; //$NON-NLS-1$
 		byte[] buffer = new byte[1000];
 		int bytesRead = 0;
 		while ((bytesRead = reader.read(buffer)) != -1) {
 			buf = buf + new String(buffer, 0, bytesRead);
 			while ((index = buf.indexOf(tag)) != -1) {
 				index += tag.length();
 				xml = buf.substring(0, index);
 				InteractionEvent event = readLegacyEvent(xml);
 				if (event != null) {
 					events.add(event);
 				}

 				if (index + endl.length() > buf.length()) {
 					buf = ""; //$NON-NLS-1$
 				} else {
 					buf = buf.substring(index + endl.length(), buf.length());
 				}

 				monitor.worked(1);
 			}
 			buffer = new byte[1000];
 		}
 	}

 	private static final String OPEN = "<"; //$NON-NLS-1$

 	private static final String CLOSE = ">"; //$NON-NLS-1$

 	private static final String SLASH = "/"; //$NON-NLS-1$

 	private static final String ENDL = "\n"; //$NON-NLS-1$

 	private static final String TAB = "\t"; //$NON-NLS-1$

 	@Deprecated
 	public String writeLegacyEvent(InteractionEvent e) {
 		try {
 			StringBuffer res = new StringBuffer();
 			String tag = "interactionEvent"; //$NON-NLS-1$
 			res.append(OPEN);
 			res.append(tag);
 			res.append(CLOSE);
 			res.append(ENDL);

 			openElement(res, "kind"); //$NON-NLS-1$
 			formatContent(res, e.getKind());
 			closeElement(res, "kind"); //$NON-NLS-1$

 			openElement(res, "date"); //$NON-NLS-1$
 			formatContent(res, e.getDate());
 			closeElement(res, "date"); //$NON-NLS-1$

 			openElement(res, "endDate"); //$NON-NLS-1$
 			formatContent(res, e.getEndDate());
 			closeElement(res, "endDate"); //$NON-NLS-1$

 			openElement(res, "originId"); //$NON-NLS-1$
 			formatContent(res, e.getOriginId());
 			closeElement(res, "originId"); //$NON-NLS-1$

 			openElement(res, "structureKind"); //$NON-NLS-1$
 			formatContent(res, e.getStructureKind());
 			closeElement(res, "structureKind"); //$NON-NLS-1$

 			openElement(res, "structureHandle"); //$NON-NLS-1$
 			formatContent(res, e.getStructureHandle());
 			closeElement(res, "structureHandle"); //$NON-NLS-1$

 			openElement(res, "navigation"); //$NON-NLS-1$
 			formatContent(res, e.getNavigation());
 			closeElement(res, "navigation"); //$NON-NLS-1$

 			openElement(res, "delta"); //$NON-NLS-1$
 			formatContent(res, e.getDelta());
 			closeElement(res, "delta"); //$NON-NLS-1$

 			openElement(res, "interestContribution"); //$NON-NLS-1$
 			formatContent(res, e.getInterestContribution());
 			closeElement(res, "interestContribution"); //$NON-NLS-1$

 			res.append(OPEN);
 			res.append(SLASH);
 			res.append(tag);
 			res.append(CLOSE);
 			res.append(ENDL);
 			return res.toString();
 		} catch (Throwable t) {
 			StatusHandler.log(new Status(IStatus.ERROR, UiUsageMonitorPlugin.ID_PLUGIN, "Could not write event", t)); //$NON-NLS-1$
 			return ""; //$NON-NLS-1$
 		}
 	}

 	private void formatContent(StringBuffer buffer, float interestContribution) {
 		buffer.append(interestContribution);
 	}

 	@SuppressWarnings("deprecation")
 	private void formatContent(StringBuffer buffer, String content) {
 		if (content != null && content.length() > 0) {
 			String xmlContent;
 			xmlContent = org.eclipse.mylyn.internal.commons.core.XmlStringConverter.convertToXmlString(content);
 			xmlContent = xmlContent.replace("\n", "\n\t\t"); //$NON-NLS-1$ //$NON-NLS-2$
 			buffer.append(xmlContent);
 		}
 	}

 	private void formatContent(StringBuffer buffer, Kind kind) {
 		buffer.append(kind.toString());
 	}

 	private void formatContent(StringBuffer buffer, Date date) {
 		buffer.append(dateFormat.format(date));
 	}

 	private void openElement(StringBuffer buffer, String tag) {
 		buffer.append(TAB);
 		buffer.append(OPEN);
 		buffer.append(tag);
 		buffer.append(CLOSE);
 	}

 	private void closeElement(StringBuffer buffer, String tag) {
 		buffer.append(OPEN);
 		buffer.append(SLASH);
 		buffer.append(tag);
 		buffer.append(CLOSE);
 		buffer.append(ENDL);
 	}

 	public InteractionEvent readLegacyEvent(String xml) {
 		Reader reader = new StringReader(xml);
 		HtmlStreamTokenizer tokenizer = new HtmlStreamTokenizer(reader, null);
 		String kind = ""; //$NON-NLS-1$
 		String startDate = ""; //$NON-NLS-1$
 		String endDate = ""; //$NON-NLS-1$
 		String originId = ""; //$NON-NLS-1$
 		String structureKind = ""; //$NON-NLS-1$
 		String structureHandle = ""; //$NON-NLS-1$
 		String navigation = ""; //$NON-NLS-1$
 		String delta = ""; //$NON-NLS-1$
 		String interest = ""; //$NON-NLS-1$
 		try {
 			for (Token token = tokenizer.nextToken(); token.getType() != Token.EOF; token = tokenizer.nextToken()) {
 				if (token.getValue().toString().equals("<kind>")) { //$NON-NLS-1$
 					kind = readStringContent(tokenizer, "</kind>"); //$NON-NLS-1$
 					kind = kind.toLowerCase(Locale.ENGLISH);
 				} else if (token.getValue().toString().equals("<date>")) { //$NON-NLS-1$
 					startDate = readStringContent(tokenizer, "</date>"); //$NON-NLS-1$
 				} else if (token.getValue().toString().equals("<endDate>")) { //$NON-NLS-1$
 					endDate = readStringContent(tokenizer, "</endDate>"); //$NON-NLS-1$
 				} else if (token.getValue().toString().equals("<originId>")) { //$NON-NLS-1$
 					originId = readStringContent(tokenizer, "</originId>"); //$NON-NLS-1$
 				} else if (token.getValue().toString().equals("<structureKind>")) { //$NON-NLS-1$
 					structureKind = readStringContent(tokenizer, "</structureKind>"); //$NON-NLS-1$
 				} else if (token.getValue().toString().equals("<structureHandle>")) { //$NON-NLS-1$
 					structureHandle = readStringContent(tokenizer, "</structureHandle>"); //$NON-NLS-1$
 				} else if (token.getValue().toString().equals("<navigation>")) { //$NON-NLS-1$
 					navigation = readStringContent(tokenizer, "</navigation>"); //$NON-NLS-1$
 				} else if (token.getValue().toString().equals("<delta>")) { //$NON-NLS-1$
 					delta = readStringContent(tokenizer, "</delta>"); //$NON-NLS-1$
 				} else if (token.getValue().toString().equals("<interestContribution>")) { //$NON-NLS-1$
 					interest = readStringContent(tokenizer, "</interestContribution>"); //$NON-NLS-1$
 				}
 			}
 			float interestFloatVal = 0;
 			try {
 				interestFloatVal = Float.parseFloat(interest);
 			} catch (NumberFormatException nfe) {
 				// ignore for empty interest values
 			}
 			InteractionEvent event = new InteractionEvent(Kind.fromString(kind), structureKind, structureHandle,
 					originId, navigation, delta, interestFloatVal, dateFormat.parse(startDate),
 					dateFormat.parse(endDate));
 			return event;

 		} catch (ParseException e) {
 			System.err.println("readevent: " + xml); //$NON-NLS-1$
 			e.printStackTrace();
 		} catch (IOException e) {
 			System.err.println("readevent: " + xml); //$NON-NLS-1$
 			e.printStackTrace();
 		} catch (Exception e) {
 			System.err.println("readevent: " + xml); //$NON-NLS-1$
 			e.printStackTrace();
 		}

 		return null;
 	}

 	@SuppressWarnings("deprecation")
 	private String readStringContent(HtmlStreamTokenizer tokenizer, String endTag) throws IOException, ParseException {
 		StringBuffer content = new StringBuffer();
 		Token token = tokenizer.nextToken();
 		while (!token.getValue().toString().equals(endTag)) {
 			if (content.length() > 0) {
 				content.append(' ');
 			}
 			content.append(token.getValue().toString());
 			token = tokenizer.nextToken();
 		}
 		return org.eclipse.mylyn.internal.commons.core.XmlStringConverter.convertXmlToString(content.toString()).trim();
 	}

 	public static DateFormat dateFormat() {
 		return (DateFormat) dateFormat.clone();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2004, 2009 Tasktop Technologies and others.
	* 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:
	* Tasktop Technologies - initial API and implementation
	* Ken Sueda - XML serialization
	*******************************************************************************/

	package org.eclipse.mylyn.internal.monitor.usage;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.Reader;
	import java.io.StringReader;
	import java.text.DateFormat;
	import java.text.ParseException;
	import java.text.SimpleDateFormat;
	import java.util.ArrayList;
	import java.util.Date;
	import java.util.List;
	import java.util.Locale;
	import java.util.concurrent.CopyOnWriteArrayList;
	import java.util.zip.ZipEntry;
	import java.util.zip.ZipFile;

	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.NullProgressMonitor;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.mylyn.commons.core.StatusHandler;
	import org.eclipse.mylyn.commons.net.HtmlStreamTokenizer;
	import org.eclipse.mylyn.commons.net.HtmlStreamTokenizer.Token;
	import org.eclipse.mylyn.internal.context.core.InteractionContextExternalizer;
	import org.eclipse.mylyn.monitor.core.AbstractMonitorLog;
	import org.eclipse.mylyn.monitor.core.IInteractionEventListener;
	import org.eclipse.mylyn.monitor.core.InteractionEvent;
	import org.eclipse.mylyn.monitor.core.InteractionEvent.Kind;

	/**
	* @author Mik Kersten TODO: use buffered output stream for better performance?
	*/
	public class InteractionEventLogger extends AbstractMonitorLog implements IInteractionEventListener {

	private int eventAccumulartor = 0;

	private final List<InteractionEvent> queue = new CopyOnWriteArrayList<InteractionEvent>();

	private final InteractionEventObfuscator handleObfuscator = new InteractionEventObfuscator();

	private static final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S z", Locale.ENGLISH); //$NON-NLS-1$

	public InteractionEventLogger(File outputFile) {
	this.outputFile = outputFile;
	}

	public synchronized void interactionObserved(InteractionEvent event) {
	// System.err.println("> " + event); //$NON-NLS-1$
	if (UiUsageMonitorPlugin.getDefault() == null) {
	StatusHandler.log(new Status(IStatus.WARNING, UiUsageMonitorPlugin.ID_PLUGIN,
	"Attempted to log event before usage monitor start")); //$NON-NLS-1$
	}
	if (UiUsageMonitorPlugin.getDefault().isObfuscationEnabled()) {
	String obfuscatedHandle = handleObfuscator.obfuscateHandle(event.getStructureKind(),
	event.getStructureHandle());
	event = new InteractionEvent(event.getKind(), event.getStructureKind(), obfuscatedHandle,
	event.getOriginId(), event.getNavigation(), event.getDelta(), event.getInterestContribution());
	}
	try {
	if (started) {
	String xml = getXmlForEvent(event);
	if (outputStream != null) {
	outputStream.write(xml.getBytes());
	}
	} else if (event != null) {
	queue.add(event);
	}
	eventAccumulartor++;
	} catch (Throwable t) {
	StatusHandler.log(new Status(IStatus.WARNING, UiUsageMonitorPlugin.ID_PLUGIN,
	"Could not log interaction event", t)); //$NON-NLS-1$
	}
	}

	@Override
	public void startMonitoring() {
	super.startMonitoring();
	for (InteractionEvent queuedEvent : queue) {
	interactionObserved(queuedEvent);
	}
	queue.clear();
	}

	@Override
	public void stopMonitoring() {
	super.stopMonitoring();
	if (UiUsageMonitorPlugin.getDefault() != null) {
	UiUsageMonitorPlugin.getDefault().incrementObservedEvents(eventAccumulartor);
	}
	eventAccumulartor = 0;
	}

	private String getXmlForEvent(InteractionEvent event) {
	return writeLegacyEvent(event);
	}

	/**
	* @return true if successfully cleared
	*/
	public synchronized void clearInteractionHistory() throws IOException {
	this.clearInteractionHistory(true);
	}

	public synchronized void clearInteractionHistory(boolean startMonitoring) throws IOException {
	stopMonitoring();
	outputStream = new FileOutputStream(outputFile, false);
	outputStream.flush();
	outputStream.close();
	outputFile.delete();
	outputFile.createNewFile();
	if (startMonitoring) {
	startMonitoring();
	}
	}

	public List<InteractionEvent> getHistoryFromFile(File file) {
	return getHistoryFromFile(file, new NullProgressMonitor());
	}

	public List<InteractionEvent> getHistoryFromFile(File file, IProgressMonitor monitor) {

	List<InteractionEvent> events = new ArrayList<InteractionEvent>();
	InputStream inputStream = null;
	long fileLength = 0;

	ZipFile zip = null;
	try {
	// The file may be a zip file...
	if (file.getName().endsWith(".zip")) { //$NON-NLS-1$
	zip = new ZipFile(file);
	if (zip.entries().hasMoreElements()) {
	ZipEntry entry = zip.entries().nextElement();
	inputStream = zip.getInputStream(entry);
	fileLength = entry.getSize();
	}
	} else {
	inputStream = new FileInputStream(file);
	fileLength = file.length();
	}

	//450: the approximate size of an event in XML
	int numberOfEventsEstimate = (int) (fileLength / 450);

	monitor.beginTask(Messages.InteractionEventLogger_Reading_History_From_File, numberOfEventsEstimate);

	getHistoryFromStream(inputStream, events, monitor);

	} catch (Exception e) {
	StatusHandler.log(new Status(IStatus.ERROR, UiUsageMonitorPlugin.ID_PLUGIN,
	"Could not read interaction history", e)); //$NON-NLS-1$
	} finally {
	if (inputStream != null) {
	try {
	inputStream.close();
	} catch (IOException e) {
	StatusHandler.log(new Status(IStatus.ERROR, UiUsageMonitorPlugin.ID_PLUGIN,
	"unable to close input stream", e)); //$NON-NLS-1$
	}
	}
	if (zip != null) {
	try {
	zip.close();
	} catch (IOException e) {
	// ignore
	}
	}
	}

	monitor.done();

	return events;
	}

	/**
	* @param events
	* @param monitor
	* @param tag
	* @param endl
	* @param buf
	*/
	private void getHistoryFromStream(InputStream reader, List<InteractionEvent> events, IProgressMonitor monitor)
	throws IOException {
	String xml;
	int index;
	String buf = ""; //$NON-NLS-1$
	String tag = "</" + InteractionContextExternalizer.ELMNT_INTERACTION_HISTORY_OLD + ">"; //$NON-NLS-1$ //$NON-NLS-2$
	String endl = "\r\n"; //$NON-NLS-1$
	byte[] buffer = new byte[1000];
	int bytesRead = 0;
	while ((bytesRead = reader.read(buffer)) != -1) {
	buf = buf + new String(buffer, 0, bytesRead);
	while ((index = buf.indexOf(tag)) != -1) {
	index += tag.length();
	xml = buf.substring(0, index);
	InteractionEvent event = readLegacyEvent(xml);
	if (event != null) {
	events.add(event);
	}

	if (index + endl.length() > buf.length()) {
	buf = ""; //$NON-NLS-1$
	} else {
	buf = buf.substring(index + endl.length(), buf.length());
	}

	monitor.worked(1);
	}
	buffer = new byte[1000];
	}
	}

	private static final String OPEN = "<"; //$NON-NLS-1$

	private static final String CLOSE = ">"; //$NON-NLS-1$

	private static final String SLASH = "/"; //$NON-NLS-1$

	private static final String ENDL = "\n"; //$NON-NLS-1$

	private static final String TAB = "\t"; //$NON-NLS-1$

	@Deprecated
	public String writeLegacyEvent(InteractionEvent e) {
	try {
	StringBuffer res = new StringBuffer();
	String tag = "interactionEvent"; //$NON-NLS-1$
	res.append(OPEN);
	res.append(tag);
	res.append(CLOSE);
	res.append(ENDL);

	openElement(res, "kind"); //$NON-NLS-1$
	formatContent(res, e.getKind());
	closeElement(res, "kind"); //$NON-NLS-1$

	openElement(res, "date"); //$NON-NLS-1$
	formatContent(res, e.getDate());
	closeElement(res, "date"); //$NON-NLS-1$

	openElement(res, "endDate"); //$NON-NLS-1$
	formatContent(res, e.getEndDate());
	closeElement(res, "endDate"); //$NON-NLS-1$

	openElement(res, "originId"); //$NON-NLS-1$
	formatContent(res, e.getOriginId());
	closeElement(res, "originId"); //$NON-NLS-1$

	openElement(res, "structureKind"); //$NON-NLS-1$
	formatContent(res, e.getStructureKind());
	closeElement(res, "structureKind"); //$NON-NLS-1$

	openElement(res, "structureHandle"); //$NON-NLS-1$
	formatContent(res, e.getStructureHandle());
	closeElement(res, "structureHandle"); //$NON-NLS-1$

	openElement(res, "navigation"); //$NON-NLS-1$
	formatContent(res, e.getNavigation());
	closeElement(res, "navigation"); //$NON-NLS-1$

	openElement(res, "delta"); //$NON-NLS-1$
	formatContent(res, e.getDelta());
	closeElement(res, "delta"); //$NON-NLS-1$

	openElement(res, "interestContribution"); //$NON-NLS-1$
	formatContent(res, e.getInterestContribution());
	closeElement(res, "interestContribution"); //$NON-NLS-1$

	res.append(OPEN);
	res.append(SLASH);
	res.append(tag);
	res.append(CLOSE);
	res.append(ENDL);
	return res.toString();
	} catch (Throwable t) {
	StatusHandler.log(new Status(IStatus.ERROR, UiUsageMonitorPlugin.ID_PLUGIN, "Could not write event", t)); //$NON-NLS-1$
	return ""; //$NON-NLS-1$
	}
	}

	private void formatContent(StringBuffer buffer, float interestContribution) {
	buffer.append(interestContribution);
	}

	@SuppressWarnings("deprecation")
	private void formatContent(StringBuffer buffer, String content) {
	if (content != null && content.length() > 0) {
	String xmlContent;
	xmlContent = org.eclipse.mylyn.internal.commons.core.XmlStringConverter.convertToXmlString(content);
	xmlContent = xmlContent.replace("\n", "\n\t\t"); //$NON-NLS-1$ //$NON-NLS-2$
	buffer.append(xmlContent);
	}
	}

	private void formatContent(StringBuffer buffer, Kind kind) {
	buffer.append(kind.toString());
	}

	private void formatContent(StringBuffer buffer, Date date) {
	buffer.append(dateFormat.format(date));
	}

	private void openElement(StringBuffer buffer, String tag) {
	buffer.append(TAB);
	buffer.append(OPEN);
	buffer.append(tag);
	buffer.append(CLOSE);
	}

	private void closeElement(StringBuffer buffer, String tag) {
	buffer.append(OPEN);
	buffer.append(SLASH);
	buffer.append(tag);
	buffer.append(CLOSE);
	buffer.append(ENDL);
	}

	public InteractionEvent readLegacyEvent(String xml) {
	Reader reader = new StringReader(xml);
	HtmlStreamTokenizer tokenizer = new HtmlStreamTokenizer(reader, null);
	String kind = ""; //$NON-NLS-1$
	String startDate = ""; //$NON-NLS-1$
	String endDate = ""; //$NON-NLS-1$
	String originId = ""; //$NON-NLS-1$
	String structureKind = ""; //$NON-NLS-1$
	String structureHandle = ""; //$NON-NLS-1$
	String navigation = ""; //$NON-NLS-1$
	String delta = ""; //$NON-NLS-1$
	String interest = ""; //$NON-NLS-1$
	try {
	for (Token token = tokenizer.nextToken(); token.getType() != Token.EOF; token = tokenizer.nextToken()) {
	if (token.getValue().toString().equals("<kind>")) { //$NON-NLS-1$
	kind = readStringContent(tokenizer, "</kind>"); //$NON-NLS-1$
	kind = kind.toLowerCase(Locale.ENGLISH);
	} else if (token.getValue().toString().equals("<date>")) { //$NON-NLS-1$
	startDate = readStringContent(tokenizer, "</date>"); //$NON-NLS-1$
	} else if (token.getValue().toString().equals("<endDate>")) { //$NON-NLS-1$
	endDate = readStringContent(tokenizer, "</endDate>"); //$NON-NLS-1$
	} else if (token.getValue().toString().equals("<originId>")) { //$NON-NLS-1$
	originId = readStringContent(tokenizer, "</originId>"); //$NON-NLS-1$
	} else if (token.getValue().toString().equals("<structureKind>")) { //$NON-NLS-1$
	structureKind = readStringContent(tokenizer, "</structureKind>"); //$NON-NLS-1$
	} else if (token.getValue().toString().equals("<structureHandle>")) { //$NON-NLS-1$
	structureHandle = readStringContent(tokenizer, "</structureHandle>"); //$NON-NLS-1$
	} else if (token.getValue().toString().equals("<navigation>")) { //$NON-NLS-1$
	navigation = readStringContent(tokenizer, "</navigation>"); //$NON-NLS-1$
	} else if (token.getValue().toString().equals("<delta>")) { //$NON-NLS-1$
	delta = readStringContent(tokenizer, "</delta>"); //$NON-NLS-1$
	} else if (token.getValue().toString().equals("<interestContribution>")) { //$NON-NLS-1$
	interest = readStringContent(tokenizer, "</interestContribution>"); //$NON-NLS-1$
	}
	}
	float interestFloatVal = 0;
	try {
	interestFloatVal = Float.parseFloat(interest);
	} catch (NumberFormatException nfe) {
	// ignore for empty interest values
	}
	InteractionEvent event = new InteractionEvent(Kind.fromString(kind), structureKind, structureHandle,
	originId, navigation, delta, interestFloatVal, dateFormat.parse(startDate),
	dateFormat.parse(endDate));
	return event;

	} catch (ParseException e) {
	System.err.println("readevent: " + xml); //$NON-NLS-1$
	e.printStackTrace();
	} catch (IOException e) {
	System.err.println("readevent: " + xml); //$NON-NLS-1$
	e.printStackTrace();
	} catch (Exception e) {
	System.err.println("readevent: " + xml); //$NON-NLS-1$
	e.printStackTrace();
	}

	return null;
	}

	@SuppressWarnings("deprecation")
	private String readStringContent(HtmlStreamTokenizer tokenizer, String endTag) throws IOException, ParseException {
	StringBuffer content = new StringBuffer();
	Token token = tokenizer.nextToken();
	while (!token.getValue().toString().equals(endTag)) {
	if (content.length() > 0) {
	content.append(' ');
	}
	content.append(token.getValue().toString());
	token = tokenizer.nextToken();
	}
	return org.eclipse.mylyn.internal.commons.core.XmlStringConverter.convertXmlToString(content.toString()).trim();
	}

	public static DateFormat dateFormat() {
	return (DateFormat) dateFormat.clone();
	}
	}