Cobertura example source code file (SwitchData.java)

This example Cobertura source code file (SwitchData.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

branchcoveragedata, classnotfoundexception, comparable, comparable, hasbeeninstrumented, io, ioexception, lock, lock, reentrantlock, serializable, serializable, switchdata, switchdata, util

The Cobertura SwitchData.java source code

/*
 * Cobertura - http://cobertura.sourceforge.net/
 *
 * Copyright (C) 2006 Jiri Mares
 *
 * 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.Arrays;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * <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 class SwitchData implements BranchCoverageData, Comparable, Serializable,
		HasBeenInstrumented
{
	private static final long serialVersionUID = 9;

	private transient Lock lock;

	private int switchNumber;
	
	private long defaultHits;

	private long[] hits;
	
	private int[] keys;

	public SwitchData(int switchNumber, int[] keys)
	{
		super();
		this.switchNumber = switchNumber;
		defaultHits = 0;
		hits = new long[keys.length];
		Arrays.fill(hits, 0);
		this.keys = new int[keys.length];
		System.arraycopy(keys, 0, this.keys, 0, keys.length);
		initLock();
	}

	public SwitchData(int switchNumber, int min, int max)
	{
		super();
		this.switchNumber = switchNumber;
		defaultHits = 0;
		hits = new long[max - min + 1];
		Arrays.fill(hits, 0);
		this.keys = new int[max - min + 1];
		for (int i = 0; min <= max; keys[i++] = min++);
		initLock();
	}

	public SwitchData(int switchNumber)
	{
		this(switchNumber, new int[0]);
	}
	
	private void initLock()
	{
		 lock = new ReentrantLock();
	}

	public int compareTo(Object o)
	{
		if (!o.getClass().equals(SwitchData.class))
			return Integer.MAX_VALUE;
		return this.switchNumber - ((SwitchData) o).switchNumber;
	}
	
	void touchBranch(int branch,int new_hits) 
	{
		lock.lock();
		try
		{
			if (branch == -1)
				defaultHits++;
			else 
			{
				if (hits.length <= branch)
				{
					long[] old = hits;
					hits = new long[branch + 1];
					System.arraycopy(old, 0, hits, 0, old.length);
					Arrays.fill(hits, old.length, hits.length - 1, 0);
				}
				hits[branch]+=new_hits;
			}
		}
		finally
		{
			lock.unlock();
		}
	}
	
	public int getSwitchNumber()
	{
		return this.switchNumber;
	}

	public long getHits(int branch)
	{
		lock.lock();
		try
		{
			if (hits.length > branch)
				return hits[branch];
			return -1;
		}
		finally
		{
			lock.unlock();
		}
	}

	public long getDefaultHits()
	{
		lock.lock();
		try
		{
			return defaultHits;
		}
		finally
		{
			lock.unlock();
		}
	}

	public double getBranchCoverageRate()
	{
		lock.lock();
		try
		{
			int branches = hits.length + 1;
			int hit = (defaultHits > 0) ? 1 : 0;
			for (int i = hits.length - 1; i >= 0; hit += ((hits[i--] > 0) ? 1 : 0));
			return ((double) hit) / branches;
		}
		finally
		{
			lock.unlock();
		}
	}

	public boolean equals(Object obj)
	{
		if (this == obj)
			return true;
		if ((obj == null) || !(obj.getClass().equals(this.getClass())))
			return false;

		SwitchData switchData = (SwitchData) obj;
		getBothLocks(switchData);
		try
		{
			return (this.defaultHits == switchData.defaultHits)
					&& (Arrays.equals(this.hits, switchData.hits))
					&& (this.switchNumber == switchData.switchNumber);
		}
		finally
		{
			lock.unlock();
			switchData.lock.unlock();
		}
	}

	public int hashCode()
	{
		return this.switchNumber;
	}

	public int getNumberOfCoveredBranches()
	{
		lock.lock();
		try
		{
			int ret = (defaultHits > 0) ? 1 : 0;
			for (int i = hits.length -1; i >= 0;i--) 
			{
				if (hits[i] > 0) ret++;
			}
			return ret;
		}
		finally
		{
			lock.unlock();
		}
	}

	public int getNumberOfValidBranches()
	{
		lock.lock();
		try
		{
			return hits.length + 1;
		}
		finally
		{
			lock.unlock();
		}
	}

	public void merge(BranchCoverageData coverageData)
	{
		SwitchData switchData = (SwitchData) coverageData;
		getBothLocks(switchData);
		try
		{
			defaultHits += switchData.defaultHits;
			for (int i = Math.min(hits.length, switchData.hits.length) - 1; i >= 0; i--)
				hits[i] += switchData.hits[i];
			if (switchData.hits.length > hits.length)
			{
				long[] old = hits;
				hits = new long[switchData.hits.length];
				System.arraycopy(old, 0, hits, 0, old.length);
				System.arraycopy(switchData.hits, old.length, hits, old.length, hits.length - old.length);
			}
			if ((this.keys.length == 0) && (switchData.keys.length > 0))
				this.keys = switchData.keys;
		}
		finally
		{
			lock.unlock();
			switchData.lock.unlock();
		}

	}

	private void getBothLocks(SwitchData 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();
	}
}