home | career | drupal | java | mac | mysql | perl | scala | uml | unix

Groovy example source code file (ComplexKeyHashMap.java)

This example Groovy source code file (ComplexKeyHashMap.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Groovy tags/keywords

complexkeyhashmap, complexkeyhashmap, default_capacity, entry, entry, entryiterator, maximum_capacity, maximum_capacity, minimum_capacity, nosuchelementexception, object, object, util

The Groovy ComplexKeyHashMap.java source code

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * Licensed 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.codehaus.groovy.util;

import java.util.NoSuchElementException;

public class ComplexKeyHashMap
{
  public static class Entry {
    public int hash;
    public Entry next;
    public Object value;

    public Object getValue() {
      return value;
    }

    public void setValue(Object value) {
      this.value = value;
    }
  }

  protected Entry table [];

  protected static final int DEFAULT_CAPACITY = 32;
  protected static final int MINIMUM_CAPACITY = 4;
  protected static final int MAXIMUM_CAPACITY = 1 << 28;

  protected int size;
  protected transient int threshold;

  public ComplexKeyHashMap() {
      init(DEFAULT_CAPACITY);
  }

    public ComplexKeyHashMap(boolean b) {
    }

  public ComplexKeyHashMap(int expectedMaxSize) {
    init (capacity(expectedMaxSize));
  }

  public static int hash(int h) {
    h += ~(h << 9);
    h ^=  (h >>> 14);
    h +=  (h << 4);
    h ^=  (h >>> 10);
    return h;
  }

  public int size() {
      return size;
  }

  public boolean isEmpty() {
      return size == 0;
  }

  public void clear() {
      Object[] tab = table;
      for (int i = 0; i < tab.length; i++)
          tab[i] = null;
      size = 0;
  }

  public void init(int initCapacity) {
      threshold = (initCapacity * 6)/8;
      table = new Entry[initCapacity];
  }

  public void resize(int newLength) {
      Entry[] oldTable = table;
      int oldLength = table.length;

      Entry[] newTable = new Entry[newLength];

      for (int j = 0; j < oldLength; j++) {

        for (Entry e = oldTable [j]; e != null;) {
          Entry next = e.next;
          int index = e.hash & (newLength-1);

          e.next = newTable[index];
          newTable [index] = e;

          e = next;
        }
      }

      table = newTable;
      threshold = (6 * newLength) / 8;
  }

  private int capacity(int expectedMaxSize) {
      // Compute min capacity for expectedMaxSize given a load factor of 3/4
      int minCapacity = (8 * expectedMaxSize)/6;

      // Compute the appropriate capacity
      int result;
      if (minCapacity > MAXIMUM_CAPACITY || minCapacity < 0) {
          result = MAXIMUM_CAPACITY;
      } else {
          result = MINIMUM_CAPACITY;
          while (result < minCapacity)
              result <<= 1;
      }
      return result;
  }

  public interface EntryIterator {
      boolean hasNext ();
      Entry   next ();
  }


    public ComplexKeyHashMap.Entry[] getTable() {
        return table;
    }

  public EntryIterator  getEntrySetIterator() {
        return new EntryIterator() {
            Entry next;       // next entry to return
            int index;        // current slot
            Entry current;    // current entry

            {
                Entry[] t = table;
                int i = t.length;
                Entry n = null;
                if (size != 0) { // advance to first entry
                    while (i > 0 && (n = t[--i]) == null) {}
                }
                next = n;
                index = i;
            }

            public boolean hasNext() {
                return next != null;
            }

            public Entry next() {
                return nextEntry();
            }

            Entry nextEntry() {
                Entry e = next;
                if (e == null)
                    throw new NoSuchElementException();

                Entry n = e.next;
                Entry[] t = table;
                int i = index;
                while (n == null && i > 0)
                    n = t[--i];
                index = i;
                next = n;
                return current = e;
            }
        };
  }
}

Other Groovy examples (source code examples)

Here is a short list of links related to this Groovy ComplexKeyHashMap.java source code file:

new blog posts

 

Copyright 1998-2014 Alvin Alexander, alvinalexander.com
All Rights Reserved.