A hash map that uses primitive ints for the key rather than objects.
- * - *Note that this class is for internal optimization purposes only, and may - * not be supported in future releases of Apache Commons Lang. Utilities of - * this sort may be included in future releases of Apache Commons Collections.
- * - * @author Justin Couch - * @author Alex Chaffee (alex@apache.org) - * @author Stephen Colebourne - * @since 2.0 - * @version $Revision$ - * @see java.util.HashMap - */ -class IntHashMap { - - /** - * The hash table data. - */ - private transient Entry table[]; - - /** - * The total number of entries in the hash table. - */ - private transient int count; - - /** - * The table is rehashed when its size exceeds this threshold. (The - * value of this field is (int)(capacity * loadFactor).) - * - * @serial - */ - private int threshold; - - /** - * The load factor for the hashtable. - * - * @serial - */ - private float loadFactor; - - /** - *Innerclass that acts as a datastructure to create a new entry in the - * table.
- */ - private static class Entry { - int hash; -// int key; // not used currently - Object value; - Entry next; - - /** - *Create a new entry with the given values.
- * - * @param hash The code used to hash the object with - * @param key The key used to enter this in the table - * @param value The value for this key - * @param next A reference to the next entry in the table - */ - protected Entry(int hash, int key, Object value, Entry next) { - this.hash = hash; -// this.key = key; - this.value = value; - this.next = next; - } - } - - /** - *Constructs a new, empty hashtable with a default capacity and load
- * factor, which is 20 and 0.75 respectively.
Constructs a new, empty hashtable with the specified initial capacity
- * and default load factor, which is 0.75.
Constructs a new, empty hashtable with the specified initial - * capacity and the specified load factor.
- * - * @param initialCapacity the initial capacity of the hashtable. - * @param loadFactor the load factor of the hashtable. - * @throws IllegalArgumentException if the initial capacity is less - * than zero, or if the load factor is nonpositive. - */ - public IntHashMap(int initialCapacity, float loadFactor) { - super(); - if (initialCapacity < 0) { - throw new IllegalArgumentException("Illegal Capacity: " + initialCapacity); - } - if (loadFactor <= 0) { - throw new IllegalArgumentException("Illegal Load: " + loadFactor); - } - if (initialCapacity == 0) { - initialCapacity = 1; - } - - this.loadFactor = loadFactor; - table = new Entry[initialCapacity]; - threshold = (int) (initialCapacity * loadFactor); - } - - /** - *Returns the number of keys in this hashtable.
- * - * @return the number of keys in this hashtable. - */ - public int size() { - return count; - } - - /** - *Tests if this hashtable maps no keys to values.
- * - * @returntrue if this hashtable maps no keys to values;
- * false otherwise.
- */
- public boolean isEmpty() {
- return count == 0;
- }
-
- /**
- * Tests if some key maps into the specified value in this hashtable.
- * This operation is more expensive than the containsKey
- * method.
Note that this method is identical in functionality to containsValue, - * (which is part of the Map interface in the collections framework).
- * - * @param value a value to search for. - * @returntrue if and only if some key maps to the
- * value argument in this hashtable as
- * determined by the equals method;
- * false otherwise.
- * @throws NullPointerException if the value is null.
- * @see #containsKey(int)
- * @see #containsValue(Object)
- * @see java.util.Map
- */
- public boolean contains(Object value) {
- if (value == null) {
- throw new NullPointerException();
- }
-
- Entry tab[] = table;
- for (int i = tab.length; i-- > 0;) {
- for (Entry e = tab[i]; e != null; e = e.next) {
- if (e.value.equals(value)) {
- return true;
- }
- }
- }
- return false;
- }
-
- /**
- * Returns true if this HashMap maps one or more keys
- * to this value.
Note that this method is identical in functionality to contains - * (which predates the Map interface).
- * - * @param value value whose presence in this HashMap is to be tested. - * @return booleantrue if the value is contained
- * @see java.util.Map
- * @since JDK1.2
- */
- public boolean containsValue(Object value) {
- return contains(value);
- }
-
- /**
- * Tests if the specified object is a key in this hashtable.
- * - * @param key possible key. - * @returntrue if and only if the specified object is a
- * key in this hashtable, as determined by the equals
- * method; false otherwise.
- * @see #contains(Object)
- */
- public boolean containsKey(int key) {
- Entry tab[] = table;
- int hash = key;
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry e = tab[index]; e != null; e = e.next) {
- if (e.hash == hash) {
- return true;
- }
- }
- return false;
- }
-
- /**
- * Returns the value to which the specified key is mapped in this map.
- * - * @param key a key in the hashtable. - * @return the value to which the key is mapped in this hashtable; - *null if the key is not mapped to any value in
- * this hashtable.
- * @see #put(int, Object)
- */
- public Object get(int key) {
- Entry tab[] = table;
- int hash = key;
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry e = tab[index]; e != null; e = e.next) {
- if (e.hash == hash) {
- return e.value;
- }
- }
- return null;
- }
-
- /**
- * Increases the capacity of and internally reorganizes this - * hashtable, in order to accommodate and access its entries more - * efficiently.
- * - *This method is called automatically when the number of keys - * in the hashtable exceeds this hashtable's capacity and load - * factor.
- */ - protected void rehash() { - int oldCapacity = table.length; - Entry oldMap[] = table; - - int newCapacity = oldCapacity * 2 + 1; - Entry newMap[] = new Entry[newCapacity]; - - threshold = (int) (newCapacity * loadFactor); - table = newMap; - - for (int i = oldCapacity; i-- > 0;) { - for (Entry old = oldMap[i]; old != null;) { - Entry e = old; - old = old.next; - - int index = (e.hash & 0x7FFFFFFF) % newCapacity; - e.next = newMap[index]; - newMap[index] = e; - } - } - } - - /** - *Maps the specified key to the specified
- * value in this hashtable. The key cannot be
- * null.
The value can be retrieved by calling the get method
- * with a key that is equal to the original key.
null if it did not have one.
- * @throws NullPointerException if the key is null.
- * @see #get(int)
- */
- public Object put(int key, Object value) {
- // Makes sure the key is not already in the hashtable.
- Entry tab[] = table;
- int hash = key;
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry e = tab[index]; e != null; e = e.next) {
- if (e.hash == hash) {
- Object old = e.value;
- e.value = value;
- return old;
- }
- }
-
- if (count >= threshold) {
- // Rehash the table if the threshold is exceeded
- rehash();
-
- tab = table;
- index = (hash & 0x7FFFFFFF) % tab.length;
- }
-
- // Creates the new entry.
- Entry e = new Entry(hash, key, value, tab[index]);
- tab[index] = e;
- count++;
- return null;
- }
-
- /**
- * Removes the key (and its corresponding value) from this - * hashtable.
- * - *This method does nothing if the key is not present in the - * hashtable.
- * - * @param key the key that needs to be removed. - * @return the value to which the key had been mapped in this hashtable, - * ornull if the key did not have a mapping.
- */
- public Object remove(int key) {
- Entry tab[] = table;
- int hash = key;
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry e = tab[index], prev = null; e != null; prev = e, e = e.next) {
- if (e.hash == hash) {
- if (prev != null) {
- prev.next = e.next;
- } else {
- tab[index] = e.next;
- }
- count--;
- Object oldValue = e.value;
- e.value = null;
- return oldValue;
- }
- }
- return null;
- }
-
- /**
- * Clears this hashtable so that it contains no keys.
- */ - public synchronized void clear() { - Entry tab[] = table; - for (int index = tab.length; --index >= 0;) { - tab[index] = null; - } - count = 0; - } - -} diff --git a/src/test/org/apache/commons/lang/IntHashMapTest.java b/src/test/org/apache/commons/lang/IntHashMapTest.java deleted file mode 100644 index ffe4aedc2..000000000 --- a/src/test/org/apache/commons/lang/IntHashMapTest.java +++ /dev/null @@ -1,142 +0,0 @@ -/* - * 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.commons.lang; - -import junit.framework.Test; -import junit.framework.TestCase; -import junit.framework.TestSuite; -import junit.textui.TestRunner; - -/** - * Tests for the IntHashMap class. - * - * @author Steven Caswell - * @version $Id$ - */ -public class IntHashMapTest extends TestCase { - - public static void main(String[] args) { - TestRunner.run(suite()); - } - - public static Test suite() { - TestSuite suite = new TestSuite(IntHashMapTest.class); - suite.setName("IntHashMapTest Tests"); - return suite; - } - - public void testConstructor() { - try { - new IntHashMap(-1, 0.0f); - fail(); - } catch (IllegalArgumentException e) { - assertEquals("Illegal Capacity: -1", e.getMessage()); - } - try { - new IntHashMap(1, 0.0f); - fail(); - } catch (IllegalArgumentException e) { - assertEquals("Illegal Load: 0.0", e.getMessage()); - } - new IntHashMap(0, 1.0f); - - try { - new IntHashMap(-1); - fail(); - } catch (IllegalArgumentException e) { - assertEquals("Illegal Capacity: -1", e.getMessage()); - } - IntHashMap map1 = new IntHashMap(0); - assertEquals(0, map1.size()); - } - - public void testClear() { - IntHashMap map = new IntHashMap(); - assertNull(map.put(1, "hello")); - assertNull(map.put(2, "world")); - assertEquals(2, map.size()); - map.clear(); - assertEquals(0, map.size()); - } - - public void testContainsKey() { - IntHashMap map = new IntHashMap(); - assertNull(map.put(1, "hello")); - assertNull(map.put(2, "world")); - assertEquals(2, map.size()); - assertTrue(map.containsKey(1)); - assertTrue(map.containsKey(2)); - assertFalse(map.containsKey(3)); - } - - public void testContains() { - IntHashMap map = new IntHashMap(); - assertNull(map.put(1, "hello")); - assertNull(map.put(2, "world")); - assertEquals(2, map.size()); - assertTrue(map.containsValue("hello")); - assertTrue(map.containsValue("world")); - assertFalse(map.containsValue("goodbye")); - try { - map.containsValue(null); - fail(); - } catch(NullPointerException e) { - } - } - - public void testContainsValue() { - IntHashMap map = new IntHashMap(); - assertNull(map.put(1, "hello")); - assertNull(map.put(2, "world")); - assertEquals(2, map.size()); - assertTrue(map.containsValue("hello")); - assertTrue(map.containsValue("world")); - assertFalse(map.containsValue("goodbye")); - try { - map.containsValue(null); - fail(); - } catch(NullPointerException e) { - } - } - - public void testIsEmpty() { - IntHashMap map = new IntHashMap(); - assertTrue(map.isEmpty()); - assertNull(map.put(1, "hello")); - assertEquals(1, map.size()); - assertFalse(map.isEmpty()); - } - - public void testPut() { - IntHashMap map = new IntHashMap(); - assertNull(map.put(1, "hello")); - assertNull(map.put(2, "world")); - assertEquals(2, map.size()); - assertEquals("hello", map.put(1, "hellooooo")); - } - - public void testRemove() { - IntHashMap map = new IntHashMap(); - assertNull(map.put(1, "hello")); - assertNull(map.put(2, "world")); - assertEquals(2, map.size()); - assertEquals("hello", map.remove(1)); - assertEquals(1, map.size()); - assertNull(map.remove(3)); - } - -} diff --git a/src/test/org/apache/commons/lang/LangTestSuite.java b/src/test/org/apache/commons/lang/LangTestSuite.java index fe2ccbafb..c313e94f1 100644 --- a/src/test/org/apache/commons/lang/LangTestSuite.java +++ b/src/test/org/apache/commons/lang/LangTestSuite.java @@ -65,7 +65,6 @@ public class LangTestSuite extends TestCase { suite.addTest(EnumUtilsTest.suite()); suite.addTest(IllegalClassExceptionTest.suite()); suite.addTest(IncompleteArgumentExceptionTest.suite()); - suite.addTest(IntHashMapTest.suite()); suite.addTest(LocaleUtilsTest.suite()); suite.addTest(NotImplementedExceptionTest.suite()); suite.addTest(NullArgumentExceptionTest.suite());