/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.giraph.block_app.reducers.array;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.fail;
  
  import org.apache.giraph.block_app.reducers.array.HugeArrayUtils.ObjectStriping;
  import org.junit.Test;
  
  public class ObjectStripingTest {
  
    private void testStriping(int size, int splits) {
      ObjectStriping striping = new ObjectStriping(size, splits);
  
      int numPerSplit = size / splits;
  
      int prevSplitIndex = 0;
      int prevInsideIndex = -1;
  
      assertEquals(0, striping.getSplitStart(0));
  
      for (int i = 0; i < size; i++) {
        int splitIndex = striping.getSplitIndex(i);
        int insideIndex = striping.getInsideIndex(i);
  
  
        if (prevInsideIndex + 1 == striping.getSplitSize(prevSplitIndex)) {
          assertEquals(i, striping.getSplitStart(splitIndex));
          assertEquals(splitIndex, prevSplitIndex + 1);
          assertEquals(insideIndex, 0);
        } else {
          assertEquals(splitIndex, prevSplitIndex);
          assertEquals(insideIndex, prevInsideIndex + 1);
        }
  
        int splitSize = striping.getSplitSize(splitIndex);
        if (splitSize != numPerSplit && splitSize != numPerSplit + 1) {
          fail(splitSize + " " + numPerSplit);
        }
        prevSplitIndex = splitIndex;
        prevInsideIndex = insideIndex;
      }
  
      assertEquals(prevSplitIndex + 1, splits);
      assertEquals(prevInsideIndex + 1, striping.getSplitSize(prevSplitIndex));
    }
  
    @Test
    public void test() {
      testStriping(5, 5);
      testStriping(6, 5);
      testStriping(7, 5);
      testStriping(9, 5);
      testStriping(10, 5);
      testStriping(100, 5);
      testStriping(101, 5);
      testStriping(104, 5);
    }
  }