From 0b221815cba124b1ed7bc3c94c38a4dcf867894a Mon Sep 17 00:00:00 2001 From: gmungoc Date: Mon, 3 Oct 2016 14:21:26 +0100 Subject: [PATCH] JAL-98 throw exception (unhandled) for int overthrow while counting --- src/jalview/ext/android/SparseIntArray.java | 33 +++++++++ test/jalview/ext/android/SparseIntArrayTest.java | 85 +++++++++++++++++++++- 2 files changed, 116 insertions(+), 2 deletions(-) diff --git a/src/jalview/ext/android/SparseIntArray.java b/src/jalview/ext/android/SparseIntArray.java index e286cb4..2b9c4af 100644 --- a/src/jalview/ext/android/SparseIntArray.java +++ b/src/jalview/ext/android/SparseIntArray.java @@ -355,6 +355,8 @@ public class SparseIntArray implements Cloneable * @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) { @@ -362,6 +364,7 @@ public class SparseIntArray implements Cloneable int i = ContainerHelpers.binarySearch(mKeys, mSize, key); if (i >= 0) { + checkOverflow(mValues[i], toAdd); mValues[i] += toAdd; newValue = mValues[i]; } @@ -389,4 +392,34 @@ public class SparseIntArray implements Cloneable } 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); + } + } + } } diff --git a/test/jalview/ext/android/SparseIntArrayTest.java b/test/jalview/ext/android/SparseIntArrayTest.java index 3919e33..0ce0467 100644 --- a/test/jalview/ext/android/SparseIntArrayTest.java +++ b/test/jalview/ext/android/SparseIntArrayTest.java @@ -1,6 +1,7 @@ package jalview.ext.android; import static org.testng.Assert.assertEquals; +import static org.testng.Assert.fail; import org.testng.annotations.Test; @@ -35,9 +36,89 @@ public class SparseIntArrayTest assertEquals(counter.add('Q', 4), 11); counter.put('x', Integer.MAX_VALUE); - counter.add('x', 1); + try + { + counter.add('x', 1); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } counter.put('y', Integer.MIN_VALUE); - counter.add('y', -1); + try + { + counter.add('y', -1); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } } + + @Test(groups = "Functional") + public void testCheckOverflow() + { + // things that don't overflow: + SparseIntArray.checkOverflow(Integer.MAX_VALUE, 0); + SparseIntArray.checkOverflow(Integer.MAX_VALUE, -1); + SparseIntArray.checkOverflow(Integer.MAX_VALUE, Integer.MIN_VALUE); + SparseIntArray.checkOverflow(Integer.MAX_VALUE, -Integer.MAX_VALUE); + SparseIntArray.checkOverflow(0, -Integer.MAX_VALUE); + SparseIntArray.checkOverflow(0, Integer.MIN_VALUE); + SparseIntArray.checkOverflow(Integer.MIN_VALUE, 0); + SparseIntArray.checkOverflow(Integer.MIN_VALUE, 1); + SparseIntArray.checkOverflow(Integer.MIN_VALUE, Integer.MAX_VALUE); + + // and some that do + try + { + SparseIntArray.checkOverflow(Integer.MAX_VALUE, 1); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } + try + { + SparseIntArray.checkOverflow(Integer.MAX_VALUE - 1, 2); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } + try + { + SparseIntArray.checkOverflow(1, Integer.MAX_VALUE); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } + try + { + SparseIntArray.checkOverflow(Integer.MIN_VALUE, -1); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } + try + { + SparseIntArray.checkOverflow(Integer.MIN_VALUE + 1, -2); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } + try + { + SparseIntArray.checkOverflow(-1, Integer.MIN_VALUE); + fail("expected exception"); + } catch (ArithmeticException e) + { + // expected + } + } + } -- 1.7.10.2