Package org.htmlunit.cyberneko.util

Class FastHashMap<K,V>

java.lang.Object
org.htmlunit.cyberneko.util.FastHashMap<K,V>
Type Parameters:
K - the type of the key
V - the type of the value
All Implemented Interfaces:
Serializable
public class FastHashMap<K,V> extends Object implements Serializable
Simple hash map implementation taken from here https://github.com/mikvor/hashmapTest/blob/master/src/main/java/map/objobj/ObjObjMap.java No concrete license specified at the source. The project is public domain. Not thread-safe! Null support was removed.
Since:
3.10.0
Author:
René Schwietzke
See Also:

  • Constructor Details

    • FastHashMap

      public FastHashMap()

    • FastHashMap

      public FastHashMap(int size, float fillFactor)

  • Method Details

    • get

      public V get(K key)

    • put

      public V put(K key, V value)

    • remove

      public V remove(K key)

    • size

      public int size()

    • keys

      public List<K> keys()
      Returns:
      a list of all keys

    • values

      public List<V> values()
      Returns:
      a list of all values

    • clear

      public void clear()
      Clears the map, reuses the data structure by clearing it out. It won't shrink the underlying array!

    • nextPowerOfTwo

      public static long nextPowerOfTwo(long x)
      Return the least power of two greater than or equal to the specified value.

      Note that this function will return 1 when the argument is 0.

      Parameters:
      x - a long integer smaller than or equal to 262.
      Returns:
      the least power of two greater than or equal to the specified value.

    • arraySize

      public static int arraySize(int expected, float f)
      Returns the least power of two smaller than or equal to 230 and larger than or equal to Math.ceil( expected / f ).
      Parameters:
      expected - the expected number of elements in a hash table.
      f - the load factor.
      Returns:
      the minimum possible size for a backing array.
      Throws:
      IllegalArgumentException - if the necessary size is larger than 230.