/*
* 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.harmony.luni.util;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Arrays;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
/**
*
* Reductive hash with two keys
*
*/
public class TwoKeyHashMap<E, K, V> extends AbstractMap<String, V> {
static final float DEFAULT_LOAD_FACTOR = 0.75f;
static final int DEFAULT_INITIAL_SIZE = 16;
private Set<Map.Entry<String, V>> entrySet;
private Collection<V> values;
private int size;
private int arrSize;
private int modCount;
private Entry<E, K, V>[] arr;
private float loadFactor;
int threshold = 0;
/**
* Constructs an empty HashMap
*/
public TwoKeyHashMap() {
this(DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR);
}
/**
* Constructs an empty HashMap
* @param initialCapacity
*/
public TwoKeyHashMap(int initialCapacity) {
this(initialCapacity, DEFAULT_LOAD_FACTOR);
}
/**
* Constructs an empty HashMap
* @param initialCapacity
* @param initialLoadFactor
*/
public TwoKeyHashMap(int initialCapacity, float initialLoadFactor) {
if (initialCapacity < 0) {
throw new IllegalArgumentException("initialCapacity should be >= 0");
}
if (initialLoadFactor <= 0) {
throw new IllegalArgumentException("initialLoadFactor should be > 0");
}
loadFactor = initialLoadFactor;
if (initialCapacity == Integer.MAX_VALUE) {
initialCapacity--;
}
arrSize = initialCapacity > 0 ? initialCapacity : 1;
threshold = (int) (arrSize * loadFactor);
arr = new Entry[arrSize + 1];
}
/**
* Returns a collection view of the values
*/
public Collection<V> values() {
if (values == null) {
values = new ValuesCollectionImpl();
}
return values;
}
/**
* Returns a collection view of the mappings
*/
public Set<Map.Entry<String, V>> entrySet() {
if (entrySet == null) {
entrySet = new EntrySetImpl();
}
return entrySet;
}
/**
* Clears the map
*/
public void clear() {
modCount++;
size = 0;
Arrays.fill(arr, 0, arr.length, null);
}
/**
* Removes the mapping for the keys
* @param key1
* @param key2
* @return
*/
public V remove(Object key1, Object key2) {
Entry<E, K, V> e = removeEntry(key1, key2);
return null != e ? e.value : null;
}
/**
* Associates the specified value with the specified keys in this map
* @param key1
* @param key2
* @param value
* @return
*/
public V put(E key1, K key2, V value) {
if (key1 == null && key2 == null) {
int index = arrSize;
if (arr[index] == null) {
arr[index] = createEntry(0, null, null, value, null);
size++;
modCount++;
return null;
} else {
V oldValue = arr[index].value;
arr[index].value = value;
return oldValue;
}
}
int hash = key1.hashCode() + key2.hashCode();
int index = (hash & 0x7fffffff) % arrSize;
Entry<E, K, V> e = arr[index];
while (e != null) {
if (hash == e.hash && key1.equals(e.getKey1()) && key2.equals(e.getKey2())) {
V oldValue = e.value;
e.value = value;
return oldValue;
}
e = e.next;
}
arr[index] = createEntry(hash, key1, key2, value, arr[index]);
size++;
modCount++;
if (size > threshold) {
rehash();
}
return null;
}
/**
* Rehash the map
*
*/
void rehash() {
int newArrSize = (arrSize + 1) * 2 + 1;
if (newArrSize < 0) {
newArrSize = Integer.MAX_VALUE - 1;
}
Entry<E, K, V>[] newArr = new Entry[newArrSize + 1];
for (int i = 0; i < arr.length - 1; i++) {
Entry<E, K, V> entry = arr[i];
while (entry != null) {
Entry<E, K, V> next = entry.next;
int newIndex = (entry.hash & 0x7fffffff) % newArrSize;
entry.next = newArr[newIndex];
newArr[newIndex] = entry;
entry = next;
}
}
newArr[newArrSize] = arr[arrSize]; // move null entry
arrSize = newArrSize;
// The maximum array size is reached, increased loadFactor
// will keep array from further growing
if (arrSize == Integer.MAX_VALUE) {
loadFactor *= 10;
}
threshold = (int) (arrSize * loadFactor);
arr = newArr;
}
/**
* Returns true if this map contains a mapping for the specified keys
* @param key1
* @param key2
* @return
*/
public boolean containsKey(Object key1, Object key2) {
return findEntry(key1, key2) != null;
}
/**
* Return the value by keys
* @param key1
* @param key2
* @return
*/
public V get(Object key1, Object key2) {
Entry<E, K, V> e = findEntry(key1, key2);
if (e != null) {
return e.value;
}
return null;
}
/**
* Returns true if this map contains no key-value mappings
*/
public boolean isEmpty() {
return size == 0;
}
/**
* Returns the number of mappings
*/
public int size() {
return size;
}
/**
* Creates new entry
* @param hashCode
* @param key1
* @param key2
* @param value
* @param next
* @return
*/
Entry<E, K, V> createEntry(int hashCode, E key1, K key2,
V value, Entry<E, K, V> next) {
return new Entry<E, K, V>(hashCode, key1, key2, value, next);
}
/**
* Creates entries iterator
* @return
*/
Iterator<Map.Entry<String, V>> createEntrySetIterator() {
return new EntryIteratorImpl();
}
/**
* Creates values iterator
* @return
*/
Iterator<V> createValueCollectionIterator() {
return new ValueIteratorImpl();
}
/**
* Entry implementation for the TwoKeyHashMap class
*
*/
public static class Entry<E, K, V> implements Map.Entry<String, V> {
int hash;
E key1;
K key2;
V value;
Entry<E, K, V> next;
public Entry(int hash, E key1, K key2, V value, Entry<E, K, V> next) {
this.hash = hash;
this.key1 = key1;
this.key2 = key2;
this.value = value;
this.next = next;
}
public String getKey() {
return key1.toString() + key2.toString();
}
public E getKey1() {
return key1;
}
public K getKey2() {
return key2;
}
public V getValue() {
return value;
}
public V setValue(V value) {
V oldValue = this.value;
this.value = value;
return oldValue;
}
public boolean equals(Object obj) {
if (!(obj instanceof Entry)) {
return false;
}
Entry<?, ?, ?> e = (Entry<?, ?, ?>) obj;
Object getKey1 = e.getKey1();
Object getKey2 = e.getKey2();
Object getValue = e.getValue();
if ((key1 == null && getKey1 != null) ||
(key2 == null && getKey2 != null) ||
(value == null && getValue != null) ||
!key1.equals(e.getKey1()) ||
!key2.equals(e.getKey2()) ||
!value.equals(getValue)) {
return false;
}
return true;
}
public int hashCode() {
int hash1 = (key1 == null ? 0 : key1.hashCode());
int hash2 = (key2 == null ? 0 : key2.hashCode());
return (hash1 + hash2) ^ (value == null ? 0 : value.hashCode());
}
}
class EntrySetImpl extends AbstractSet<Map.Entry<String, V>> {
public int size() {
return size;
}
public void clear() {
TwoKeyHashMap.this.clear();
}
public boolean isEmpty() {
return size == 0;
}
public boolean contains(Object obj) {
if (!(obj instanceof Entry)) {
return false;
}
Entry<?, ?, ?> entry = (Entry<?, ?, ?>) obj;
Entry<E, K, V> entry2 = findEntry(entry.getKey1(), entry.getKey2());
if (entry2 == null) {
return false;
}
Object value = entry.getValue();
Object value2 = entry2.getValue();
return value == null ? value2 == null : value.equals(value2);
}
public boolean remove(Object obj) {
if (!(obj instanceof Entry)) {
return false;
}
return removeEntry(((Entry) obj).getKey1(), ((Entry)obj).getKey2()) != null;
}
public Iterator<Map.Entry<String, V>> iterator() {
return createEntrySetIterator();
}
}
// Iterates Entries inside the Map
class EntryIteratorImpl implements Iterator<Map.Entry<String, V>> {
private int startModCount;
private boolean found;
private int curr = -1;
private int returned_index = -1;
private Entry<E, K, V> curr_entry;
private Entry<E, K, V> returned_entry;
EntryIteratorImpl() {
startModCount = modCount;
}
public boolean hasNext() {
if (found) {
return true;
}
if (curr_entry != null) {
curr_entry = curr_entry.next;
}
if (curr_entry == null) {
for (curr++; curr < arr.length && arr[curr] == null; curr++) {
}
if (curr < arr.length) {
curr_entry = arr[curr];
}
}
return found = (curr_entry != null);
}
public Map.Entry<String, V> next() {
if (modCount != startModCount) {
throw new ConcurrentModificationException();
}
if (!hasNext()) {
throw new NoSuchElementException();
}
found = false;
returned_index = curr;
returned_entry = curr_entry;
return (Map.Entry<String, V>)curr_entry;
}
public void remove() {
if (returned_index == -1) {
throw new IllegalStateException();
}
if (modCount != startModCount) {
throw new ConcurrentModificationException();
}
Entry<E, K, V> p = null;
Entry<E, K, V> e = arr[returned_index];
while (e != returned_entry) {
p = e;
e = e.next;
}
if (p != null) {
p.next = returned_entry.next;
} else {
arr[returned_index] = returned_entry.next;
}
size--;
modCount++;
startModCount++;
returned_index = -1;
}
}
private final Entry<E, K, V> findEntry(Object key1, Object key2) {
if (key1 == null && key2 == null) {
return arr[arrSize];
}
int hash = key1.hashCode() + key2.hashCode();
int index = (hash & 0x7fffffff) % arrSize;
Entry<E, K, V> e = arr[index];
while (e != null) {
if (hash == e.hash && key1.equals(e.getKey1()) && key2.equals(e.getKey2())) {
return e;
}
e = e.next;
}
return null;
}
// Removes entry
private final Entry<E, K, V> removeEntry(Object key1, Object key2) {
if (key1 == null && key2 == null) {
int index = arrSize;
if (arr[index] != null) {
Entry<E, K, V> ret = arr[index];
arr[index] = null;
size--;
modCount++;
return ret;
}
return null;
}
int hash = key1.hashCode() + key2.hashCode();
int index = (hash & 0x7fffffff) % arrSize;
Entry<E, K, V> e = arr[index];
Entry<E, K, V> prev = e;
while (e != null) {
if (hash == e.hash && key1.equals(e.getKey1()) && key2.equals(e.getKey2())) {
if (prev == e) {
arr[index] = e.next;
} else {
prev.next = e.next;
}
size--;
modCount++;
return e;
}
prev = e;
e = e.next;
}
return null;
}
/**
* An instance is returned by the values() call.
*/
class ValuesCollectionImpl extends AbstractCollection<V> {
public int size() {
return size;
}
public void clear() {
TwoKeyHashMap.this.clear();
}
public boolean isEmpty() {
return size == 0;
}
public Iterator<V> iterator() {
return createValueCollectionIterator();
}
public boolean contains(Object obj) {
return containsValue(obj);
}
}
class ValueIteratorImpl implements Iterator<V> {
private EntryIteratorImpl itr;
ValueIteratorImpl() {
super();
this.itr = new EntryIteratorImpl();
}
public V next() {
return itr.next().getValue();
}
public void remove() {
itr.remove();
}
public boolean hasNext() {
return itr.hasNext();
}
}
}
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