libgdx API

com.badlogic.gdx.utils
Class ObjectIntMap<K>

java.lang.Object
  extended by com.badlogic.gdx.utils.ObjectIntMap<K>

public class ObjectIntMap<K>
extends java.lang.Object

An unordered map where the values are ints. This implementation is a cuckoo hash map using 3 hashes, random walking, and a small stash for problematic keys. Null keys are not 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 ObjectIntMap.Entries<K>
           
static class ObjectIntMap.Entry<K>
           
static class ObjectIntMap.Keys<K>
           
static class ObjectIntMap.Values
           
 
Field Summary
 int size
           
 
Constructor Summary
ObjectIntMap()
          Creates a new map with an initial capacity of 32 and a load factor of 0.8.
ObjectIntMap(int initialCapacity)
          Creates a new map with a load factor of 0.8.
ObjectIntMap(int initialCapacity, float loadFactor)
          Creates a new map with the specified initial capacity and load factor.
 
Method Summary
 void clear()
           
 boolean containsKey(K key)
           
 boolean containsValue(int value)
          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.
 ObjectIntMap.Entries<K> entries()
          Returns an iterator for the entries in the map.
 K findKey(int value)
          Returns the key for the specified value, or null if it is not in the map.
 int get(K key, int defaultValue)
           
 int getAndIncrement(K key, int defaultValue, int increment)
          Returns the key's current value and increments the stored value.
 ObjectIntMap.Keys<K> keys()
          Returns an iterator for the keys in the map.
 void put(K key, int value)
           
 void putAll(ObjectIntMap<K> map)
           
 int remove(K key, int defaultValue)
           
 java.lang.String toString()
           
 ObjectIntMap.Values 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

ObjectIntMap

public ObjectIntMap()
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.


ObjectIntMap

public ObjectIntMap(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.


ObjectIntMap

public ObjectIntMap(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 void put(K key,
                int value)

putAll

public void putAll(ObjectIntMap<K> map)

get

public int get(K key,
               int defaultValue)
Parameters:
defaultValue - Returned if the key was not associated with a value.

getAndIncrement

public int getAndIncrement(K key,
                           int defaultValue,
                           int increment)
Returns the key's current value and increments the stored value. If the key is not in the map, defaultValue + increment is put into the map.


remove

public int remove(K key,
                  int defaultValue)

clear

public void clear()

containsValue

public boolean containsValue(int value)
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(K key)

findKey

public K findKey(int value)
Returns the key for the specified value, or null if it is not in the map. Note this traverses the entire map and compares every value, which may be an expensive operation.


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 ObjectIntMap.Entries<K> 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 ObjectIntMap.Entries constructor for nested or multithreaded iteration.


values

public ObjectIntMap.Values 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 ObjectIntMap.Entries constructor for nested or multithreaded iteration.


keys

public ObjectIntMap.Keys<K> 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 ObjectIntMap.Entries constructor for nested or multithreaded iteration.


libgdx API

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