uimaj-core/src/test/java/org/apache/uima/internal/util/Obj2IntIdentityHashMapTest.java

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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
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 *   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.uima.internal.util;

import java.util.HashMap;
import java.util.Map;
import java.util.Random;

import junit.framework.TestCase;

public class Obj2IntIdentityHashMapTest extends TestCase {
  
  // a number of extras needed to cause rebalance
  // is > 1 because it might turn out randomly that
  // the puts clear all the REMOVED_KEY values
  // needs to be > than 1/2 the capacity/2
  private static final int  REBAL = 32;  

  Obj2IntIdentityHashMap<Integer> ihm;
  
  private static Integer[] I = new Integer[300];
  static {for (int i = 0; i < I.length; i++) I[i] = i;}

  Map<Integer, Integer> im = new HashMap<>();
  
  public void setUp() {
    ihm = new Obj2IntIdentityHashMap<>(Integer.class, new Integer(Integer.MIN_VALUE));
  }

  public void testBasic() {
    
    Integer I15 = 15;
    Integer I188 = 188;
    
    ihm.put(I15, 150);
    ihm.put(I188, 1880);
    assertEquals(2, ihm.size());
    assertEquals(150, (int)ihm.get(I15));
    assertEquals(1880, (int)ihm.get(I188));
    assertEquals(0, (int)ihm.get(188));  // not identity equal

    assertEquals(0, ihm.remove(18));
    assertEquals(150, (int)ihm.remove(I15));
    assertEquals(1, ihm.size());
    
//    for (IntEntry<Integer> ie : ihm) {
//      assertEquals(ie.getKey(), 188);
//    }
    
    assertEquals(1880, (int)ihm.remove(I188));
    assertEquals(0, ihm.size());
//    for (IntEntry<Integer> ie : ihm) {
//      fail();  // should be empty
//    }
    
  }
  
  public void testRebalance() {
    // 100 elements, require 256 table (128 * .66 = 85)
    for (int i = 1; i < 101; i++) {
      ihm.put(I[i], i * 10);
    }
    
    // have 100 elements, remove 100 elements
    for (int i = 1; i < 101; i++) {
      assertEquals(i*10, (int)ihm.remove(I[i]));
    }
    
    
    assertEquals(0, ihm.size());
    
    assertEquals(64, ihm.getCapacity());
    
    for (int i = 1; i < 101 + REBAL; i++) {
      ihm.put(I[i + 100], i * 10);  // add different keys, so may use some new slots
    }
    
    assertEquals(256, ihm.getCapacity()); //because above are different adds, likely into non-removed positions
    
    // have 100 elements, remove 100 elements
    for (int i = 1; i < 101 + REBAL; i++) {
      assertEquals(i*10, (int)ihm.remove(I[i + 100]));
    }
   
    assertEquals(64, ihm.getCapacity());
    
  }
  
  private Integer J(int v) {
    im.putIfAbsent(v, v);
    return im.get(v);
  }
  
  public void testRandom() {
    int countAdd = 0;
    int dupsA = 0;
    int notPres = 0;
    int countRmv = 0;
    
    long seed = // -6616473831883690L;
        new Random().nextLong();
    System.out.println("Random seed for Obj2IntIdentityHashMapTest: " + seed);
    Random r = new Random(seed);
    
    for (int i = 1; i < 1024 * 512; i++) {
      int k = i & 1024 - 1;
      if (k == 0) continue;
      if (r.nextInt(3) > 0) {
        int sz = ihm.size();
        if (ihm.put(J(k), -k) == 0) {
          countAdd ++;
          assertEquals(sz + 1, ihm.size());
        } else {
          dupsA++;
        }
      } else {
        int sz = ihm.size();
        if (ihm.remove(J(k)) != 0) {
          countRmv ++;
          assertEquals(sz - 1, ihm.size());
        } else {
          notPres++;
        }
        
      }
    }
    System.out.format("%s testRandom added: %,d dups: %,d rmvd: %,d notPres: %,d, size: %d%n",         
        this.getClass().getName(), countAdd, dupsA, countRmv, notPres, ihm.size());
    assertEquals(countAdd - countRmv, ihm.size() );
  }
}