// Copyright (c) 2003-2014, Jodd Team (jodd.org). All Rights Reserved.
package jodd.util.collection;
import java.io.Serializable;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
/**
* A Map that accepts int or Integer keys only. The implementation is based on
* <code>java.util.HashMap</code>. IntHashMap is about 25% faster.
*
* @see java.util.HashMap
*/
public class IntHashMap extends AbstractMap implements Cloneable, Serializable {
/**
* The hash table data.
*/
private transient Entry table[];
/**
* The total number of mappings 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).)
*/
private int threshold;
/**
* The load factor for the hashtable.
*/
private float loadFactor;
/**
* The number of times this IntHashMap has been structurally modified
* Structural modifications are those that change the number of mappings in
* the IntHashMap or otherwise modify its internal structure (e.g., rehash).
* This field is used to make iterators on Collection-views of the IntHashMap
* fail-fast.
*/
private transient int modCount;
/**
* Constructs a new, empty map with the specified initial
* capacity and the specified load factor.
*
* @param initialCapacity the initial capacity of the IntHashMap.
* @param loadFactor the load factor of the IntHashMap
* @throws IllegalArgumentException if the initial capacity is less
* than zero, or if the load factor is non-positive.
*/
public IntHashMap(int initialCapacity, float loadFactor) {
if (initialCapacity < 0) {
throw new IllegalArgumentException("Invalid initial capacity: " + initialCapacity);
}
if (loadFactor <= 0) {
throw new IllegalArgumentException("Invalid load factor: " + loadFactor);
}
if (initialCapacity == 0) {
initialCapacity = 1;
}
this.loadFactor = loadFactor;
table = new Entry[initialCapacity];
threshold = (int) (initialCapacity * loadFactor);
}
/**
* Constructs a new, empty map with the specified initial capacity
* and default load factor, which is 0.75.
*
* @param initialCapacity the initial capacity of the IntHashMap.
* @throws IllegalArgumentException if the initial capacity is less
* than zero.
*/
public IntHashMap(int initialCapacity) {
this(initialCapacity, 0.75f);
}
/**
* Constructs a new, empty map with a default capacity and load
* factor, which is 0.75.
*/
public IntHashMap() {
this(101, 0.75f);
}
/**
* Constructs a new map with the same mappings as the given map. The
* map is created with a capacity of twice the number of mappings in
* the given map or 11 (whichever is greater), and a default load factor,
* which is 0.75.
*/
public IntHashMap(Map t) {
this(Math.max(2 * t.size(), 11), 0.75f);
putAll(t);
}
/**
* Returns the number of key-value mappings in this map.
*
* @return the number of key-value mappings in this map.
*/
@Override
public int size() {
return count;
}
/**
* Returns <code>true</code> if this map contains no key-value mappings.
*
* @return <code>true</code> if this map contains no key-value mappings.
*/
@Override
public boolean isEmpty() {
return count == 0;
}
/**
* Returns <code>true</code> if this map maps one or more keys to the
* specified value.
*
* @param value value whose presence in this map is to be tested.
* @return <code>true</code> if this map maps one or more keys to the
* specified value.
*/
@Override
public boolean containsValue(Object value) {
Entry tab[] = table;
if (value == null) {
for (int i = tab.length; i-- > 0; ) {
for (Entry e = tab[i]; e != null; e = e.next) {
if (e.value == null) {
return true;
}
}
}
}
else {
for (int i = tab.length; i-- > 0; ) {
for (Entry e = tab[i]; e != null; e = e.next) {
if (value.equals(e.value)) {
return true;
}
}
}
}
return false;
}
/**
* Returns <code>true</code> if this map contains a mapping for the specified
* key.
*
* @param key key whose presence in this Map is to be tested.
* @return <code>true</code> if this map contains a mapping for the specified
* key.
*/
@Override
public boolean containsKey(Object key) {
if (key instanceof Number) {
return containsKey(((Number) key).intValue());
}
return false;
}
/**
* Returns <code>true</code> if this map contains a mapping for the specified
* key.
*
* @param key key whose presence in this Map is to be tested.
* @return <code>true</code> if this map contains a mapping for the specified
* key.
*/
public boolean containsKey(int key) {
Entry tab[] = table;
int index = (key & 0x7FFFFFFF) % tab.length;
for (Entry e = tab[index]; e != null; e = e.next) {
if (e.key == key) {
return true;
}
}
return false;
}
/**
* Returns the value to which this map maps the specified key. Returns
* <code>null</code> if the map contains no mapping for this key. A return
* value of <code>null</code> does not <i>necessarily</i> indicate that the
* map contains no mapping for the key; it's also possible that the map
* explicitly maps the key to <code>null</code>. The <code>containsKey</code>
* operation may be used to distinguish these two cases.
*
* @param key key whose associated value is to be returned.
* @return the value to which this map maps the specified key.
*/
@Override
public Object get(Object key) {
if (key instanceof Number) {
return get(((Number) key).intValue());
}
return null;
}
/**
* Returns the value to which this map maps the specified key. Returns
* <code>null</code> if the map contains no mapping for this key. A return
* value of <code>null</code> does not <i>necessarily</i> indicate that the
* map contains no mapping for the key; it's also possible that the map
* explicitly maps the key to <code>null</code>. The <code>containsKey</code>
* operation may be used to distinguish these two cases.
*
* @param key key whose associated value is to be returned.
* @return the value to which this map maps the specified key.
*/
public Object get(int key) {
Entry tab[] = table;
int index = (key & 0x7FFFFFFF) % tab.length;
for (Entry e = tab[index]; e != null; e = e.next) {
if (e.key == key) {
return e.value;
}
}
return null;
}
/**
* Rehashes the contents of this map into a new <code>IntHashMap</code>
* instance with a larger capacity. This method is called automatically when
* the number of keys in this map exceeds its capacity and load factor.
*/
private void rehash() {
int oldCapacity = table.length;
Entry oldMap[] = table;
int newCapacity = (oldCapacity << 1) + 1;
Entry newMap[] = new Entry[newCapacity];
modCount++;
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.key & 0x7FFFFFFF) % newCapacity;
e.next = newMap[index];
newMap[index] = e;
}
}
}
/**
* Associates the specified value with the specified key in this map. If the
* map previously contained a mapping for this key, the old value is
* replaced.
*
* @param key key with which the specified value is to be associated.
* @param value value to be associated with the specified key.
* @return previous value associated with specified key, or <code>null</code> if
* there was no mapping for key. A <code>null</code> return can also indicate
* that the IntHashMap previously associated <code>null</code> with the
* specified key.
*/
@Override
public Object put(Object key, Object value) {
if (key instanceof Number) {
return put(((Number) key).intValue(), value);
}
throw new UnsupportedOperationException("IntHashMap key must be a Number");
}
/**
* Associates the specified value with the specified key in this map. If the
* map previously contained a mapping for this key, the old value is
* replaced.
*
* @param key key with which the specified value is to be associated.
* @param value value to be associated with the specified key.
* @return previous value associated with specified key, or <code>null</code> if
* there was no mapping for key. A <code>null</code> return can also indicate
* that the IntHashMap previously associated <code>null</code> with the
* specified key.
*/
public Object put(int key, Object value) {
// makes sure the key is not already in the IntHashMap.
Entry tab[] = table;
int index = (key & 0x7FFFFFFF) % tab.length;
for (Entry e = tab[index]; e != null; e = e.next) {
if (e.key == key) {
Object old = e.value;
e.value = value;
return old;
}
}
modCount++;
if (count >= threshold) {
// rehash the table if the threshold is exceeded
rehash();
tab = table;
index = (key & 0x7FFFFFFF) % tab.length;
}
// creates the new entry.
tab[index] = new Entry(key, value, tab[index]);
count++;
return null;
}
/**
* Removes the mapping for this key from this map if present.
*
* @param key key whose mapping is to be removed from the map.
* @return previous value associated with specified key, or <code>null</code> if
* there was no mapping for key. A <code>null</code> return can also indicate
* that the map previously associated <code>null</code> with the specified
* key.
*/
@Override
public Object remove(Object key) {
if (key instanceof Number) {
return remove(((Number) key).intValue());
}
return null;
}
/**
* Removes the mapping for this key from this map if present.
*
* @param key key whose mapping is to be removed from the map.
* @return previous value associated with specified key, or <code>null</code> if
* there was no mapping for key. A <code>null</code> return can also indicate
* that the map previously associated <code>null</code> with the specified
* key.
*/
public Object remove(int key) {
Entry tab[] = table;
int index = (key & 0x7FFFFFFF) % tab.length;
for (Entry e = tab[index], prev = null; e != null;
prev = e, e = e.next) {
if (e.key == key) {
modCount++;
if (prev != null) {
prev.next = e.next;
}
else {
tab[index] = e.next;
}
count--;
Object oldValue = e.value;
e.value = null;
return oldValue;
}
}
return null;
}
/**
* Copies all of the mappings from the specified map to this one.
* These mappings replace any mappings that this map had for any of the
* keys currently in the specified Map.
*
* @param t Mappings to be stored in this map.
*/
@Override
public void putAll(Map t) {
for (Object o : t.entrySet()) {
Map.Entry e = (Map.Entry) o;
put(e.getKey(), e.getValue());
}
}
/**
* Removes all mappings from this map.
*/
@Override
public void clear() {
Entry tab[] = table;
modCount++;
for (int index = tab.length; --index >= 0; ) {
tab[index] = null;
}
count = 0;
}
/**
* Returns a shallow copy of this <code>IntHashMap</code> instance: the keys and
* values themselves are not cloned.
*
* @return a shallow copy of this map.
*/
@Override
public IntHashMap clone() {
try {
IntHashMap t = (IntHashMap) super.clone();
t.table = new Entry[table.length];
for (int i = table.length; i-- > 0; ) {
t.table[i] = (table[i] != null)
? (Entry) table[i].clone() : null;
}
t.keySet = null;
t.entrySet = null;
t.values = null;
t.modCount = 0;
return t;
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
// views
private transient Set keySet;
private transient Set entrySet;
private transient Collection values;
/**
* Returns a set view of the keys contained in this map. The set is backed by
* the map, so changes to the map are reflected in the set, and vice-versa.
* The set supports element removal, which removes the corresponding mapping
* from this map, via the <code>Iterator.remove</code>,
* <code>Set.remove</code>, <code>removeAll</code>, <code>retainAll</code>,
* and <code>clear</code> operations. It does not support the
* <code>add</code> or <code>addAll</code> operations.
*
* @return a set view of the keys contained in this map.
*/
@Override
public Set<Integer> keySet() {
if (keySet == null) {
keySet = new AbstractSet<Integer>() {
@Override
public Iterator<Integer> iterator() {
return new IntHashIterator(KEYS);
}
@Override
public int size() {
return count;
}
@Override
public boolean contains(Object o) {
return containsKey(o);
}
@Override
public boolean remove(Object o) {
return IntHashMap.this.remove(o) != null;
}
@Override
public void clear() {
IntHashMap.this.clear();
}
};
}
return keySet;
}
/**
* Returns a collection view of the values contained in this map. The
* collection is backed by the map, so changes to the map are reflected in
* the collection, and vice-versa. The collection supports element removal,
* which removes the corresponding mapping from this map, via the
* <code>Iterator.remove</code>, <code>Collection.remove</code>,
* <code>removeAll</code>, <code>retainAll</code>, and <code>clear</code>
* operations. It does not support the <code>add</code> or
* <code>addAll</code> operations.
*
* @return a collection view of the values contained in this map.
*/
@Override
public Collection values() {
if (values == null) {
values = new AbstractCollection() {
@Override
public Iterator iterator() {
return new IntHashIterator(VALUES);
}
@Override
public int size() {
return count;
}
@Override
public boolean contains(Object o) {
return containsValue(o);
}
@Override
public void clear() {
IntHashMap.this.clear();
}
};
}
return values;
}
/**
* Returns a collection view of the mappings contained in this map. Each
* element in the returned collection is a <code>Map.Entry</code>. The
* collection is backed by the map, so changes to the map are reflected in
* the collection, and vice-versa. The collection supports element removal,
* which removes the corresponding mapping from the map, via the
* <code>Iterator.remove</code>, <code>Collection.remove</code>,
* <code>removeAll</code>, <code>retainAll</code>, and <code>clear</code>
* operations. It does not support the <code>add</code> or
* <code>addAll</code> operations.
*
* @return a collection view of the mappings contained in this map.
*
* @see java.util.Map.Entry
*/
@Override
public Set<Map.Entry<Integer, Object>> entrySet() {
if (entrySet == null) {
entrySet = new AbstractSet() {
@Override
public Iterator iterator() {
return new IntHashIterator(ENTRIES);
}
@Override
public boolean contains(Object o) {
if (!(o instanceof Map.Entry)) {
return false;
}
Map.Entry entry = (Map.Entry) o;
Object key = entry.getKey();
Entry tab[] = table;
int hash = (key == null ? 0 : key.hashCode());
int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry e = tab[index]; e != null; e = e.next) {
if (e.key == hash && e.equals(entry)) {
return true;
}
}
return false;
}
@Override
public boolean remove(Object o) {
if (!(o instanceof Map.Entry)) {
return false;
}
Map.Entry entry = (Map.Entry) o;
Object key = entry.getKey();
Entry tab[] = table;
int hash = (key == null ? 0 : key.hashCode());
int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry e = tab[index], prev = null; e != null;
prev = e, e = e.next) {
if (e.key == hash && e.equals(entry)) {
modCount++;
if (prev != null) {
prev.next = e.next;
}
else {
tab[index] = e.next;
}
count--;
e.value = null;
return true;
}
}
return false;
}
@Override
public int size() {
return count;
}
@Override
public void clear() {
IntHashMap.this.clear();
}
};
}
return entrySet;
}
/**
* IntHashMap collision list entry.
*/
private static class Entry implements Map.Entry<Integer, Object>, Cloneable {
int key;
Object value;
Entry next;
private Integer objectKey;
Entry(int key, Object value, Entry next) {
this.key = key;
this.value = value;
this.next = next;
}
@Override
protected Object clone() {
return new Entry(key, value,
(next == null ? null : (Entry) next.clone()));
}
// Map.Entry Ops
public Integer getKey() {
return (objectKey != null) ? objectKey :
(objectKey = Integer.valueOf(key));
}
public Object getValue() {
return value;
}
public Object setValue(Object value) {
Object oldValue = this.value;
this.value = value;
return oldValue;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof Map.Entry)) {
return false;
}
Map.Entry e = (Map.Entry) o;
return (getKey().equals(e.getKey())) &&
(value == null ? e.getValue() == null : value.equals(e.getValue()));
}
@Override
public int hashCode() {
return key ^ (value == null ? 0 : value.hashCode());
}
@Override
public String toString() {
return Integer.toString(key) + '=' + value;
}
}
// types of Iterators
private static final int KEYS = 0;
private static final int VALUES = 1;
private static final int ENTRIES = 2;
private class IntHashIterator implements Iterator {
Entry[] _table = IntHashMap.this.table;
int index = _table.length;
Entry entry;
Entry lastReturned;
int type;
/**
* The modCount value that the iterator believes that the backing
* List should have. If this expectation is violated, the iterator
* has detected concurrent modification.
*/
private int expectedModCount = modCount;
IntHashIterator(int type) {
this.type = type;
}
public boolean hasNext() {
while (entry == null && index > 0) {
entry = _table[--index];
}
return entry != null;
}
public Object next() {
if (modCount != expectedModCount) {
throw new ConcurrentModificationException();
}
while (entry == null && index > 0) {
entry = _table[--index];
}
if (entry != null) {
Entry e = lastReturned = entry;
entry = e.next;
return type == KEYS ? e.getKey() :
(type == VALUES ? e.value : e);
}
throw new NoSuchElementException();
}
public void remove() {
if (lastReturned == null) {
throw new IllegalStateException();
}
if (modCount != expectedModCount) {
throw new ConcurrentModificationException();
}
Entry[] tab = IntHashMap.this.table;
int ndx = (lastReturned.key & 0x7FFFFFFF) % tab.length;
for (Entry e = tab[ndx], prev = null; e != null;
prev = e, e = e.next) {
if (e == lastReturned) {
modCount++;
expectedModCount++;
if (prev == null) {
tab[ndx] = e.next;
}
else {
prev.next = e.next;
}
count--;
lastReturned = null;
return;
}
}
throw new ConcurrentModificationException();
}
}
}