Cobertura example source code file (CoverageDataContainer.java)

This example Cobertura source code file (CoverageDataContainer.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Cobertura tags/keywords

classnotfoundexception, coveragedata, coveragedata, coveragedatacontainer, coveragedatacontainer, hasbeeninstrumented, io, ioexception, iterator, iterator, map, object, object, reentrantlock, serializable, util

The Cobertura CoverageDataContainer.java source code

/*
 * Cobertura - http://cobertura.sourceforge.net/
 *
 * Copyright (C) 2003 jcoverage ltd.
 * Copyright (C) 2005 Mark Doliner
 * Copyright (C) 2005 Jeremy Thomerson
 * Copyright (C) 2005 Mark Sinke
 *
 * Cobertura is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * Cobertura is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Cobertura; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

package net.sourceforge.cobertura.coveragedata;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * <p>
 * Coverage data information is typically serialized to a file.
 * </p>
 *
 * <p>
 * This class implements HasBeenInstrumented so that when cobertura
 * instruments itself, it will omit this class.  It does this to
 * avoid an infinite recursion problem because instrumented classes
 * make use of this class.
 * </p>
 */
public abstract class CoverageDataContainer
		implements CoverageData, HasBeenInstrumented, Serializable
{

	private static final long serialVersionUID = 2;

	protected transient Lock lock;

	/**
	 * Each key is the name of a child, usually stored as a String or
	 * an Integer object.  Each value is information about the child,
	 * stored as an object that implements the CoverageData interface.
	 */
	Map<Object,CoverageData> children = new HashMap();

	public CoverageDataContainer()
	{
		initLock();
	}
	
	private void initLock()
	{
		lock = new ReentrantLock();
	}
	
	/**
	 * Determine if this CoverageDataContainer is equal to
	 * another one.  Subclasses should override this and
	 * make sure they implement the hashCode method.
	 *
	 * @param obj An object to test for equality.
	 * @return True if the objects are equal.
	 */
	public boolean equals(Object obj)
	{
		if (this == obj)
			return true;
		if ((obj == null) || !(obj.getClass().equals(this.getClass())))
			return false;

		CoverageDataContainer coverageDataContainer = (CoverageDataContainer)obj;
		lock.lock();
		try
		{
			return this.children.equals(coverageDataContainer.children);
		}
		finally
		{
			lock.unlock();
		}
	}

	/**
	 * @return The average branch coverage rate for all children
	 *         in this container.
	 */
	public double getBranchCoverageRate()
	{
		int number = 0;
		int numberCovered = 0;
		lock.lock();
		try
		{
			Iterator<CoverageData> iter = this.children.values().iterator();
			while (iter.hasNext())
			{
				CoverageData coverageContainer = iter.next();
				number += coverageContainer.getNumberOfValidBranches();
				numberCovered += coverageContainer.getNumberOfCoveredBranches();
			}
		}
		finally
		{
			lock.unlock();
		}
		if (number == 0)
		{
			// no branches, therefore 100% branch coverage.
			return 1d;
		}
		return (double)numberCovered / number;
	}

	/**
	 * Get a child from this container with the specified
	 * key.
	 * @param name The key used to lookup the child in the
	 *        map.
	 * @return The child object, if found, or null if not found.
	 */
	public CoverageData getChild(String name)
	{
		lock.lock();
		try
		{
			return (CoverageData)this.children.get(name);
		}
		finally
		{
			lock.unlock();
		}
	}

	/**
	 * @return The average line coverage rate for all children
	 *         in this container.  This number will be a decimal
	 *         between 0 and 1, inclusive.
	 */
	public double getLineCoverageRate()
	{
		int number = 0;
		int numberCovered = 0;
		lock.lock();
		try
		{
			Iterator<CoverageData> iter = this.children.values().iterator();
			while (iter.hasNext())
			{
				CoverageData coverageContainer = iter.next();
				number += coverageContainer.getNumberOfValidLines();
				numberCovered += coverageContainer.getNumberOfCoveredLines();
			}
		}
		finally
		{
			lock.unlock();
		}
		if (number == 0)
		{
			// no lines, therefore 100% line coverage.
			return 1d;
		}
		return (double)numberCovered / number;
	}

	/**
	 * @return The number of children in this container.
	 */
	public int getNumberOfChildren()
	{
		lock.lock();
		try
		{
			return this.children.size();
		}
		finally
		{
			lock.unlock();
		}
	}

	public int getNumberOfCoveredBranches()
	{
		int number = 0;
		lock.lock();
		try
		{
			Iterator<CoverageData> iter = this.children.values().iterator();
			while (iter.hasNext())
			{
				CoverageData coverageContainer = iter.next();
				number += coverageContainer.getNumberOfCoveredBranches();
			}
		}
		finally
		{
			lock.unlock();
		}
		return number;
	}

	public int getNumberOfCoveredLines()
	{
		int number = 0;
		lock.lock();
		try
		{
			Iterator<CoverageData> iter = this.children.values().iterator();
			while (iter.hasNext())
			{
				CoverageData coverageContainer = iter.next();
				number += coverageContainer.getNumberOfCoveredLines();
			}
		}
		finally
		{
			lock.unlock();
		}
		return number;
	}

	public int getNumberOfValidBranches()
	{
		int number = 0;
		lock.lock();
		try
		{
			Iterator<CoverageData> iter = this.children.values().iterator();
			while (iter.hasNext())
			{
				CoverageData coverageContainer = iter.next();
				number += coverageContainer.getNumberOfValidBranches();
			}
		}
		finally
		{
			lock.unlock();
		}
		return number;
	}

	public int getNumberOfValidLines()
	{
		int number = 0;
		lock.lock();
		try
		{
			Iterator<CoverageData> iter = this.children.values().iterator();
			while (iter.hasNext())
			{
				CoverageData coverageContainer = iter.next();
				number += coverageContainer.getNumberOfValidLines();
			}
		}
		finally
		{
			lock.unlock();
		}
		return number;
	}

	/**
	 * It is highly recommended that classes extending this
	 * class override this hashCode method and generate a more
	 * effective hash code.
	 */
	public int hashCode()
	{
		lock.lock();
		try
		{
			return this.children.size();
		}
		finally
		{
			lock.unlock();
		}
	}

	/**
	 * Merge two <code>CoverageDataContainers.
	 *
	 * @param coverageData The container to merge into this one.
	 */
	public void merge(CoverageData coverageData)
	{
		CoverageDataContainer container = (CoverageDataContainer)coverageData;
		getBothLocks(container);
		try
		{
			Iterator<Object> iter = container.children.keySet().iterator();
			while (iter.hasNext())
			{
				Object key = iter.next();
				CoverageData newChild = (CoverageData)container.children.get(key);
				CoverageData existingChild = (CoverageData)this.children.get(key);
				if (existingChild != null)
				{
					existingChild.merge(newChild);
				}
				else
				{
					// TODO: Shouldn't we be cloning newChild here?  I think so that
					//       would be better... but we would need to override the
					//       clone() method all over the place?
					this.children.put(key, newChild);
				}
			}
		}
		finally
		{
			lock.unlock();
			container.lock.unlock();
		}
	}

	protected void getBothLocks(CoverageDataContainer other) {
		/*
		 * To prevent deadlock, we need to get both locks or none at all.
		 * 
		 * When this method returns, the thread will have both locks.
		 * Make sure you unlock them!
		 */
		boolean myLock = false;
		boolean otherLock = false;
		while ((!myLock) || (!otherLock))
		{
			try
			{
				myLock = lock.tryLock();
				otherLock = other.lock.tryLock();
			}
			finally
			{
				if ((!myLock) || (!otherLock))
				{
					//could not obtain both locks - so unlock the one we got.
					if (myLock)
					{
						lock.unlock();
					}
					if (otherLock)
					{
						other.lock.unlock();
					}
					//do a yield so the other threads will get to work.
					Thread.yield();
				}
			}
		}
	}

	private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException
	{
		in.defaultReadObject();
		initLock();
	}
}