com.esotericsoftware.kryo.util

Class IntMap<V>

java.lang.Object

com.esotericsoftware.kryo.util.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

Field Summary

Fields

Modifier and Type	Field and Description
int	size

Constructor Summary

Constructors

Constructor and Description
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

Methods

Modifier and Type	Method and Description
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.
int	findKey(java.lang.Object value, boolean identity, int notFound) Returns the key for the specified value, or notFound if it is not in the map.
V	get(int key)
V	get(int key, V defaultValue)
V	put(int key, V value)
V	remove(int key)
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, 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)

get

public V get(int key)

get

public V get(int key,
    V defaultValue)

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.

Parameters:

identity - If true, uses == to compare the specified value with values in the map. If false, uses Object.equals(Object).

containsKey

public boolean containsKey(int key)

findKey

public int findKey(java.lang.Object value,
          boolean identity,
          int notFound)

Returns the key for the specified value, or notFound if it is not in the map. Note this traverses the entire map and compares every value, which may be an expensive operation.

Parameters:

identity - If true, uses == to compare the specified value with values in the map. If false, uses Object.equals(Object).

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