libgdx API

com.badlogic.gdx.utils
Class IntMap<V>

java.lang.Object
  extended by com.badlogic.gdx.utils.IntMap<V>

public class IntMap<V>
extends java.lang.Object

An unordered map that uses int keys. This implementation is a cuckoo hash map using 3 hashes, random walking, and a small stash for problematic keys. Null values are allowed. No allocation is done except when growing the table size.

This map performs very fast get, containsKey, and remove (typically O(1), worst case O(log(n))). Put may be a bit slower, depending on hash collisions. Load factors greater than 0.91 greatly increase the chances the map will have to rehash to the next higher POT size.

Author:
Nathan Sweet

Nested Class Summary
static class IntMap.Entries<V>
           
static class IntMap.Entry<V>
           
static class IntMap.Keys
           
static class IntMap.Values<V>
           
 
Field Summary
 int size
           
 
Constructor Summary
IntMap()
          Creates a new map with an initial capacity of 32 and a load factor of 0.8.
IntMap(int initialCapacity)
          Creates a new map with a load factor of 0.8.
IntMap(int initialCapacity, float loadFactor)
          Creates a new map with the specified initial capacity and load factor.
 
Method Summary
 void clear()
           
 boolean containsKey(int key)
           
 boolean containsValue(java.lang.Object value, boolean identity)
          Returns true if the specified value is in the map.
 void ensureCapacity(int additionalCapacity)
          Increases the size of the backing array to acommodate the specified number of additional items.
 IntMap.Entries<V> entries()
          Returns an iterator for the entries in the map.
 V get(int key)
           
 IntMap.Keys keys()
          Returns an iterator for the keys in the map.
 V put(int key, V value)
           
 void putAll(IntMap<V> map)
           
 V remove(int key)
           
 java.lang.String toString()
           
 IntMap.Values<V> values()
          Returns an iterator for the values in the map.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

size

public int size
Constructor Detail

IntMap

public IntMap()
Creates a new map with an initial capacity of 32 and a load factor of 0.8. This map will hold 25 items before growing the backing table.


IntMap

public IntMap(int initialCapacity)
Creates a new map with a load factor of 0.8. This map will hold initialCapacity * 0.8 items before growing the backing table.


IntMap

public IntMap(int initialCapacity,
              float loadFactor)
Creates a new map with the specified initial capacity and load factor. This map will hold initialCapacity * loadFactor items before growing the backing table.

Method Detail

put

public V put(int key,
             V value)

putAll

public void putAll(IntMap<V> map)

get

public V get(int key)

remove

public V remove(int key)

clear

public void clear()

containsValue

public boolean containsValue(java.lang.Object value,
                             boolean identity)
Returns true if the specified value is in the map. Note this traverses the entire map and compares every value, which may be an expensive operation.


containsKey

public boolean containsKey(int key)

ensureCapacity

public void ensureCapacity(int additionalCapacity)
Increases the size of the backing array to acommodate the specified number of additional items. Useful before adding many items to avoid multiple backing array resizes.


toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object

entries

public IntMap.Entries<V> entries()
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 IntMap.Entries constructor for nested or multithreaded iteration.


values

public IntMap.Values<V> values()
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 IntMap.Entries constructor for nested or multithreaded iteration.


keys

public IntMap.Keys keys()
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 IntMap.Entries constructor for nested or multithreaded iteration.


libgdx API

Copyright 2010 Mario Zechner (contact@badlogicgames.com), Nathan Sweet (admin@esotericsoftware.com)