libgdx API

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

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

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

An unordered map that uses long 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 LongMap.Entries<V>
           
static class LongMap.Entry<V>
           
static class LongMap.Keys
           
static class LongMap.Values<V>
           
 
Field Summary
 int size
           
 
Constructor Summary
LongMap()
          Creates a new map with an initial capacity of 32 and a load factor of 0.8.
LongMap(int initialCapacity)
          Creates a new map with a load factor of 0.8.
LongMap(int initialCapacity, float loadFactor)
          Creates a new map with the specified initial capacity and load factor.
 
Method Summary
 void clear()
           
 boolean containsKey(long 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.
 LongMap.Entries<V> entries()
          Returns an iterator for the entries in the map.
 V get(long key)
           
 LongMap.Keys keys()
          Returns an iterator for the keys in the map.
 V put(long key, V value)
           
 void putAll(LongMap<V> map)
           
 V remove(long key)
           
 java.lang.String toString()
           
 LongMap.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

LongMap

public LongMap()
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.


LongMap

public LongMap(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.


LongMap

public LongMap(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(long key,
             V value)

putAll

public void putAll(LongMap<V> map)

get

public V get(long key)

remove

public V remove(long 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(long 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 LongMap.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 LongMap.Entries constructor for nested or multithreaded iteration.


values

public LongMap.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 LongMap.Entries constructor for nested or multithreaded iteration.


keys

public LongMap.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 LongMap.Entries constructor for nested or multithreaded iteration.


libgdx API

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