/*******************************************************************************
* Copyright 2011 See AUTHORS file.
*
* 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 com.badlogic.gdx.utils;
import java.util.Iterator;
import java.util.NoSuchElementException;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.utils.ObjectMap.Entry;
/**
* An ordered or unordered map of objects. This implementation uses arrays to store the keys and values, which means
* {@link #getKey(Object, boolean) gets} do a comparison for each key in the map. This may be acceptable for small maps
* and has the benefits that keys and values can be accessed by index, which makes iteration fast. Like {@link Array},
* if ordered is false, this class avoids a memory copy when removing elements (the last element is moved to the removed
* element's position).
*
* @author Nathan Sweet
*/
public class ArrayMap<K, V> {
public K[] keys;
public V[] values;
public int size;
public boolean ordered;
private Entries entries;
private Values valuesIter;
private Keys keysIter;
/** Creates an ordered map with a capacity of 16. */
public ArrayMap() {
this(true, 16);
}
/** Creates an ordered map with the specified capacity. */
public ArrayMap(int capacity) {
this(true, capacity);
}
/**
* @param ordered
* If false, methods that remove elements may change the order of other elements in the arrays, which
* avoids a memory copy.
* @param capacity
* Any elements added beyond this will cause the backing arrays to be grown.
*/
public ArrayMap(boolean ordered, int capacity) {
this.ordered = ordered;
keys = (K[]) new Object[capacity];
values = (V[]) new Object[capacity];
}
/**
* Creates a new map with {@link #keys} and {@link #values} of the specified type.
*
* @param ordered
* If false, methods that remove elements may change the order of other elements in the arrays, which
* avoids a memory copy.
* @param capacity
* Any elements added beyond this will cause the backing arrays to be grown.
*/
public ArrayMap(boolean ordered, int capacity, Class<K> keyArrayType, Class<V> valueArrayType) {
this.ordered = ordered;
keys = (K[]) java.lang.reflect.Array.newInstance(keyArrayType, capacity);
values = (V[]) java.lang.reflect.Array.newInstance(valueArrayType, capacity);
}
/** Creates an ordered map with {@link #keys} and {@link #values} of the specified type and a capacity of 16. */
public ArrayMap(Class<K> keyArrayType, Class<V> valueArrayType) {
this(false, 16, keyArrayType, valueArrayType);
}
/**
* Creates a new map containing the elements in the specified map. The new map will have the same type of backing
* arrays and will be ordered if the specified map is ordered. The capacity is set to the number of elements, so any
* subsequent elements added will cause the backing arrays to be grown.
*/
public ArrayMap(ArrayMap array) {
this(array.ordered, array.size, (Class<K>) array.keys.getClass().getComponentType(), (Class<V>) array.values
.getClass().getComponentType());
size = array.size;
System.arraycopy(array.keys, 0, keys, 0, size);
System.arraycopy(array.values, 0, values, 0, size);
}
public void put(K key, V value) {
if (size == keys.length)
resize(Math.max(8, (int) (size * 1.75f)));
int index = indexOfKey(key);
if (index == -1)
index = size++;
keys[index] = key;
values[index] = value;
}
public void put(K key, V value, int index) {
if (size == keys.length)
resize(Math.max(8, (int) (size * 1.75f)));
int existingIndex = indexOfKey(key);
if (existingIndex != -1)
removeIndex(existingIndex);
System.arraycopy(keys, index, keys, index + 1, size - index);
System.arraycopy(values, index, values, index + 1, size - index);
keys[index] = key;
values[index] = value;
size++;
}
public void addAll(ArrayMap map) {
addAll(map, 0, map.size);
}
public void addAll(ArrayMap map, int offset, int length) {
if (offset + length > map.size)
throw new IllegalArgumentException("offset + length must be <= size: " + offset + " + " + length + " <= "
+ map.size);
int sizeNeeded = size + length - offset;
if (sizeNeeded >= keys.length)
resize(Math.max(8, (int) (sizeNeeded * 1.75f)));
System.arraycopy(map.keys, offset, keys, size, length);
System.arraycopy(map.values, offset, values, size, length);
size += length;
}
/**
* Returns the value for the specified key. Note this does a .equals() comparison of each key in reverse order until
* the specified key is found.
*/
public V get(K key) {
Object[] keys = this.keys;
int i = size - 1;
if (key == null) {
for (; i >= 0; i--)
if (keys[i] == key)
return values[i];
} else {
for (; i >= 0; i--)
if (key.equals(keys[i]))
return values[i];
}
return null;
}
/**
* Returns the key for the specified value. Note this does a comparison of each value in reverse order until the
* specified value is found.
*
* @param identity
* If true, == comparison will be used. If false, .equals() comaparison will be used.
*/
public K getKey(V value, boolean identity) {
Object[] values = this.values;
int i = size - 1;
if (identity || values == null) {
for (; i >= 0; i--)
if (values[i] == values)
return keys[i];
} else {
for (; i >= 0; i--)
if (values.equals(values[i]))
return keys[i];
}
return null;
}
public K getKeyAt(int index) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
return keys[index];
}
public V getValueAt(int index) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
return values[index];
}
public K firstKey() {
return keys[0];
}
public V firstValue() {
return values[0];
}
public void setKey(int index, K key) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
keys[index] = key;
}
public void setValue(int index, V value) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
values[index] = value;
}
public void insert(int index, K key, V value) {
if (size == keys.length)
resize(Math.max(8, (int) (size * 1.75f)));
if (ordered) {
System.arraycopy(keys, index, keys, index + 1, size - index);
System.arraycopy(values, index, values, index + 1, size - index);
} else {
keys[size] = keys[index];
values[size] = values[index];
}
size++;
keys[index] = key;
values[index] = value;
}
public boolean containsKey(K key) {
K[] keys = this.keys;
int i = size - 1;
if (key == null) {
while (i >= 0)
if (keys[i--] == key)
return true;
} else {
while (i >= 0)
if (key.equals(keys[i--]))
return true;
}
return false;
}
/**
* @param identity
* If true, == comparison will be used. If false, .equals() comaparison will be used.
*/
public boolean containsValue(V value, boolean identity) {
V[] values = this.values;
int i = size - 1;
if (identity || value == null) {
while (i >= 0)
if (values[i--] == value)
return true;
} else {
while (i >= 0)
if (value.equals(values[i--]))
return true;
}
return false;
}
public int indexOfKey(K key) {
Object[] keys = this.keys;
if (key == null) {
for (int i = 0, n = size; i < n; i++)
if (keys[i] == key)
return i;
} else {
for (int i = 0, n = size; i < n; i++)
if (key.equals(keys[i]))
return i;
}
return -1;
}
public int indexOfValue(V value, boolean identity) {
Object[] values = this.values;
if (identity || value == null) {
for (int i = 0, n = size; i < n; i++)
if (values[i] == value)
return i;
} else {
for (int i = 0, n = size; i < n; i++)
if (value.equals(values[i]))
return i;
}
return -1;
}
public V removeKey(K key) {
Object[] keys = this.keys;
if (key == null) {
for (int i = 0, n = size; i < n; i++) {
if (keys[i] == key) {
V value = values[i];
removeIndex(i);
return value;
}
}
} else {
for (int i = 0, n = size; i < n; i++) {
if (key.equals(keys[i])) {
V value = values[i];
removeIndex(i);
return value;
}
}
}
return null;
}
public boolean removeValue(V value, boolean identity) {
Object[] values = this.values;
if (identity || value == null) {
for (int i = 0, n = size; i < n; i++) {
if (values[i] == value) {
removeIndex(i);
return true;
}
}
} else {
for (int i = 0, n = size; i < n; i++) {
if (value.equals(values[i])) {
removeIndex(i);
return true;
}
}
}
return false;
}
/** Removes and returns the key/values pair at the specified index. */
public void removeIndex(int index) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
Object[] keys = this.keys;
size--;
if (ordered) {
System.arraycopy(keys, index + 1, keys, index, size - index);
System.arraycopy(values, index + 1, values, index, size - index);
} else {
keys[index] = keys[size];
values[index] = values[size];
}
keys[size] = null;
values[size] = null;
}
/** Returns the last key. */
public K peekKey() {
return keys[size - 1];
}
/** Returns the last value. */
public V peekValue() {
return values[size - 1];
}
public void clear() {
K[] keys = this.keys;
V[] values = this.values;
for (int i = 0, n = size; i < n; i++) {
keys[i] = null;
values[i] = null;
}
size = 0;
}
/**
* Reduces the size of the backing arrays to the size of the actual number of entries. This is useful to release
* memory when many items have been removed, or if it is known that more entries will not be added.
*/
public void shrink() {
resize(size);
}
/**
* Increases the size of the backing arrays to acommodate the specified number of additional entries. Useful before
* adding many entries to avoid multiple backing array resizes.
*/
public void ensureCapacity(int additionalCapacity) {
int sizeNeeded = size + additionalCapacity;
if (sizeNeeded >= keys.length)
resize(Math.max(8, sizeNeeded));
}
protected void resize(int newSize) {
K[] newKeys = (K[]) java.lang.reflect.Array.newInstance(keys.getClass().getComponentType(), newSize);
System.arraycopy(keys, 0, newKeys, 0, Math.min(keys.length, newKeys.length));
this.keys = newKeys;
V[] newValues = (V[]) java.lang.reflect.Array.newInstance(values.getClass().getComponentType(), newSize);
System.arraycopy(values, 0, newValues, 0, Math.min(values.length, newValues.length));
this.values = newValues;
}
public void reverse() {
for (int i = 0, lastIndex = size - 1, n = size / 2; i < n; i++) {
int ii = lastIndex - i;
K tempKey = keys[i];
keys[i] = keys[ii];
keys[ii] = tempKey;
V tempValue = values[i];
values[i] = values[ii];
values[ii] = tempValue;
}
}
public void shuffle() {
for (int i = size - 1; i >= 0; i--) {
int ii = MathUtils.random(i);
K tempKey = keys[i];
keys[i] = keys[ii];
keys[ii] = tempKey;
V tempValue = values[i];
values[i] = values[ii];
values[ii] = tempValue;
}
}
/**
* Reduces the size of the arrays to the specified size. If the arrays are already smaller than the specified size,
* no action is taken.
*/
public void truncate(int newSize) {
if (size <= newSize)
return;
for (int i = newSize; i < size; i++) {
keys[i] = null;
values[i] = null;
}
size = newSize;
}
public String toString() {
if (size == 0)
return "{}";
K[] keys = this.keys;
V[] values = this.values;
StringBuilder buffer = new StringBuilder(32);
buffer.append('{');
buffer.append(keys[0]);
buffer.append('=');
buffer.append(values[0]);
for (int i = 1; i < size; i++) {
buffer.append(", ");
buffer.append(keys[i]);
buffer.append('=');
buffer.append(values[i]);
}
buffer.append('}');
return buffer.toString();
}
/**
* Returns an iterator for the entries in the map. Remove is supported. Note that the same iterator instance is
* returned each time this method is called. Use the {@link Entries} constructor for nested or multithreaded
* iteration.
*/
public Entries<K, V> entries() {
if (entries == null)
entries = new Entries(this);
else
entries.reset();
return entries;
}
/**
* Returns an iterator for the values in the map. Remove is supported. Note that the same iterator instance is
* returned each time this method is called. Use the {@link Entries} constructor for nested or multithreaded
* iteration.
*/
public Values<V> values() {
if (valuesIter == null)
valuesIter = new Values(this);
else
valuesIter.reset();
return valuesIter;
}
/**
* Returns an iterator for the keys in the map. Remove is supported. Note that the same iterator instance is
* returned each time this method is called. Use the {@link Entries} constructor for nested or multithreaded
* iteration.
*/
public Keys<K> keys() {
if (keysIter == null)
keysIter = new Keys(this);
else
keysIter.reset();
return keysIter;
}
static public class Entries<K, V> implements Iterable<Entry<K, V>>, Iterator<Entry<K, V>> {
private final ArrayMap<K, V> map;
Entry<K, V> entry = new Entry();
int index;
public Entries(ArrayMap<K, V> map) {
this.map = map;
}
public boolean hasNext() {
return index < map.size;
}
public Iterator<Entry<K, V>> iterator() {
return this;
}
public Entry<K, V> next() {
if (index >= map.size)
throw new NoSuchElementException(String.valueOf(index));
entry.key = map.keys[index];
entry.value = map.values[index++];
return entry;
}
public void remove() {
index--;
map.removeIndex(index);
}
public void reset() {
index = 0;
}
}
static public class Values<V> implements Iterable<V>, Iterator<V> {
private final ArrayMap<Object, V> map;
int index;
public Values(ArrayMap<Object, V> map) {
this.map = map;
}
public boolean hasNext() {
return index < map.size;
}
public Iterator<V> iterator() {
return this;
}
public V next() {
if (index >= map.size)
throw new NoSuchElementException(String.valueOf(index));
return map.values[index++];
}
public void remove() {
index--;
map.removeIndex(index);
}
public void reset() {
index = 0;
}
}
static public class Keys<K> implements Iterable<K>, Iterator<K> {
private final ArrayMap<K, Object> map;
int index;
public Keys(ArrayMap<K, Object> map) {
this.map = map;
}
public boolean hasNext() {
return index < map.size;
}
public Iterator<K> iterator() {
return this;
}
public K next() {
if (index >= map.size)
throw new NoSuchElementException(String.valueOf(index));
return map.keys[index++];
}
public void remove() {
index--;
map.removeIndex(index);
}
public void reset() {
index = 0;
}
}
}