X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fext%2Fandroid%2FSparseIntArray.java;h=2b9c4af0467ad60bc7dc7eca4ad6009feae4e529;hb=0b221815cba124b1ed7bc3c94c38a4dcf867894a;hp=0e058032a96fc627a4110fc0c927b75282dfe006;hpb=72694ab755c766fcc84a5e329bfd066242435614;p=jalview.git

diff --git a/src/jalview/ext/android/SparseIntArray.java b/src/jalview/ext/android/SparseIntArray.java
index 0e05803..2b9c4af 100644
--- a/src/jalview/ext/android/SparseIntArray.java
+++ b/src/jalview/ext/android/SparseIntArray.java
@@ -348,21 +348,78 @@ public class SparseIntArray implements Cloneable
   }
 
   /**
-   * Method added for Jalview to increment a key's value if present, else add it
-   * with the value 1
+   * Method (copied from put) added for Jalview to efficiently increment a key's
+   * value if present, else add it with the given value. This avoids a double
+   * binary search (once to get the value, again to put the updated value).
    * 
    * @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 void increment(int key)
+  public int add(int key, int toAdd)
   {
+    int newValue = toAdd;
     int i = ContainerHelpers.binarySearch(mKeys, mSize, key);
     if (i >= 0)
     {
-      mValues[i]++;
+      checkOverflow(mValues[i], toAdd);
+      mValues[i] += toAdd;
+      newValue = mValues[i];
     }
     else
     {
-      put(key, 1);
+      i = ~i;
+      if (mSize >= mKeys.length)
+      {
+        int n = idealIntArraySize(mSize + 1);
+        int[] nkeys = new int[n];
+        int[] nvalues = new int[n];
+        System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length);
+        System.arraycopy(mValues, 0, nvalues, 0, mValues.length);
+        mKeys = nkeys;
+        mValues = nvalues;
+      }
+      if (mSize - i != 0)
+      {
+        System.arraycopy(mKeys, i, mKeys, i + 1, mSize - i);
+        System.arraycopy(mValues, i, mValues, i + 1, mSize - i);
+      }
+      mKeys[i] = key;
+      mValues[i] = toAdd;
+      mSize++;
+    }
+    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);
+      }
     }
   }
 }