Package arc.struct

Class IntFloatMap

java.lang.Object
arc.struct.IntFloatMap
All Implemented Interfaces:
Iterable<IntFloatMap.Entry>
public class IntFloatMap extends Object implements Iterable<IntFloatMap.Entry>
An unordered map where the keys are ints and values are floats. 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.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    IntFloatMap.Entries
     
    static class 
    IntFloatMap.Entry
     
    static class 
    IntFloatMap.Keys
     
    static class 
    IntFloatMap.Values
     

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    int
    size
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    IntFloatMap()
    Creates a new map with an initial capacity of 51 and a load factor of 0.8.
    IntFloatMap(int initialCapacity)
    Creates a new map with a load factor of 0.8.
    IntFloatMap(int initialCapacity, float loadFactor)
    Creates a new map with the specified initial capacity and load factor.
    IntFloatMap(IntFloatMap map)
    Creates a new map identical to the specified map.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
     
    void
    clear(int maximumCapacity)
    Clears the map and reduces the size of the backing arrays to be the specified capacity if they are larger.
    boolean
    containsKey(int key)
     
    boolean
    containsValue(float value)
    Returns true if the specified value is in the map.
    boolean
    containsValue(float value, float epsilon)
    Returns true if the specified value is in the map.
    void
    ensureCapacity(int additionalCapacity)
    Increases the size of the backing array to accommodate the specified number of additional items.
    IntFloatMap.Entries
    entries()
    Returns an iterator for the entries in the map.
    boolean
    equals(Object obj)
     
    int
    findKey(float value, int notFound)
    Returns the key for the specified value, or null if it is not in the map.
    float
    get(int key)
     
    float
    get(int key, float defaultValue)
     
    int
    hashCode()
     
    float
    increment(int key, float increment)
     
    float
    increment(int key, float defaultValue, float increment)
    Returns the key's current value and increments the stored value.
    boolean
    isEmpty()
    Returns true if the map is empty.
    Iterator<IntFloatMap.Entry>
    iterator()
     
    IntFloatMap.Keys
    keys()
    Returns an iterator for the keys in the map.
    void
    put(int key, float value)
     
    void
    putAll(IntFloatMap map)
     
    float
    remove(int key, float defaultValue)
     
    void
    shrink(int maximumCapacity)
    Reduces the size of the backing arrays to be the specified capacity or less.
    String
    toString()
     
    IntFloatMap.Values
    values()
    Returns an iterator for the values in the map.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    Methods inherited from interface java.lang.Iterable

    forEach, spliterator

  • Field Details

    • size

      public int size

  • Constructor Details

    • IntFloatMap

      public IntFloatMap()
      Creates a new map with an initial capacity of 51 and a load factor of 0.8.

    • IntFloatMap

      public IntFloatMap(int initialCapacity)
      Creates a new map with a load factor of 0.8.
      Parameters:
      initialCapacity - If not a power of two, it is increased to the next nearest power of two.

    • IntFloatMap

      public IntFloatMap(int initialCapacity, float loadFactor)
      Creates a new map with the specified initial capacity and load factor. This map will hold initialCapacity items before growing the backing table.
      Parameters:
      initialCapacity - If not a power of two, it is increased to the next nearest power of two.

    • IntFloatMap

      public IntFloatMap(IntFloatMap map)
      Creates a new map identical to the specified map.

  • Method Details

    • put

      public void put(int key, float value)

    • putAll

      public void putAll(IntFloatMap map)

    • get

      public float get(int key)

    • get

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

    • increment

      public float increment(int key, float increment)

    • increment

      public float increment(int key, float defaultValue, float 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 float remove(int key, float defaultValue)

    • isEmpty

      public boolean isEmpty()
      Returns true if the map is empty.

    • shrink

      public void shrink(int maximumCapacity)
      Reduces the size of the backing arrays to be the specified capacity or less. If the capacity is already less, nothing is done. If the map contains more items than the specified capacity, the next highest power of two capacity is used instead.

    • clear

      public void clear(int maximumCapacity)
      Clears the map and reduces the size of the backing arrays to be the specified capacity if they are larger.

    • clear

      public void clear()

    • containsValue

      public boolean containsValue(float 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.

    • containsValue

      public boolean containsValue(float value, float epsilon)
      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)

    • findKey

      public int findKey(float value, int notFound)
      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 accommodate the specified number of additional items. Useful before adding many items to avoid multiple backing array resizes.

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • iterator

      public Iterator<IntFloatMap.Entry> iterator()
      Specified by:
      iterator in interface Iterable<IntFloatMap.Entry>

    • entries

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

    • values

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

    • keys

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