a simple wrapper class; less overhead than keeping a separate Integer counter object and going through object reallocation and/or autoboxing on each counter increment

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@90 348d0f76-0448-11de-a6fe-93d51630548a

playground/java/src/org/broadinstitute/sting/indels/CountedObject.java

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+package org.broadinstitute.sting.indels;
+
+/** Utility class that makes working with counted objects slightly easier (and faster). 
+ * Consider a "generic" counter representation as Map<Object,Integer>: updating the counter would require
+ * int i = map.get(obj).intValue(); i++; map.set(obj,i) - cumbersome, and also inefficient due to extra invocations of Integer
+ * constructor. This ObjectCounter class can increment its internally kept counter without the need to rebuild any objects,
+ * so one can use, e.g. "Set<CountedObject> myset;" and then "myset.get(obj).increment()".  Note that equals() method
+ * defines counted objects to be the same iff the underlying objects are equal, regardless of the
+ * counter value. Should the counters be compared, one has to use the getters on the two counted objects
+ * and compare the results.
+ * @author asivache
+ *
+ */
+public class CountedObject<T> {
+	private T mObject;
+	int mCounter;
+	
+	/** Creates new counter associated with the passed object and assigns the default count of 1 
+	 * 
+	 * @param o object to start counting for
+	 */
+	public CountedObject(T o) {
+		mObject = o;
+		mCounter = 1;
+	}
+
+	/** Creates new counter associated with the object o and assigns specified initial count to it
+	 * 
+	 * @param o object to start counting for
+	 * @param n initial count
+	 */
+	public CountedObject(T o, int n) {
+		mObject = o;
+		mCounter = n;
+	}
+
+    public T getObject() { return mObject; }
+	public int getCount() { return mCounter; }
+	public void increment() { mCounter++;}
+	public void increment(int n) { mCounter+=n; }
+	public void decrement() { mCounter--; }
+	public void decrement(int n) { mCounter -= n; }
+    @Override
+    public boolean equals(Object o) {
+        if ( this == o ) return true;
+        if ( ! ( o instanceof CountedObject )) return false;
+        return mObject.equals(o);
+    }
+
+}