* order in the case of <code>valueAt(int)<code>.
* </p>
*/
+
+/*
+ * Imported into Jalview September 2016
+ * Change log:
+ * Sep 2016 method add(int, int) added for more efficient increment of counts
+ * (a single binary search, rather than one on read and one on write)
+ */
public class SparseIntArray implements Cloneable
{
private int[] mKeys;
* @param key
* @oparam toAdd
* @return the new value of the count for the key
+ * @throw ArithmeticException if the result would exceed the maximum value of
+ * an int
*/
public int add(int key, int toAdd)
{
int i = ContainerHelpers.binarySearch(mKeys, mSize, key);
if (i >= 0)
{
+ checkOverflow(mValues[i], toAdd);
mValues[i] += toAdd;
newValue = mValues[i];
}
}
return newValue;
}
+
+ /**
+ * Throws ArithmeticException if adding addend to value would exceed the range
+ * of int
+ *
+ * @param value
+ * @param addend
+ */
+ static void checkOverflow(int value, int addend)
+ {
+ /*
+ * test cases being careful to avoid overflow while testing!
+ */
+ if (addend > 0)
+ {
+ if (value > 0 && Integer.MAX_VALUE - value < addend)
+ {
+ throw new ArithmeticException("Integer overflow adding " + addend
+ + " to " + value);
+ }
+ }
+ else if (addend < 0)
+ {
+ if (value < 0 && Integer.MIN_VALUE - value > addend)
+ {
+ throw new ArithmeticException("Integer underflow adding " + addend
+ + " to " + value);
+ }
+ }
+ }
}