Package org.htmlunit.cyberneko.util

Class FastHashMap<K,​V>

  • Type Parameters:
    K - the type of the key
    V - the type of the value
    All Implemented Interfaces:
    java.io.Serializable
    public class FastHashMap<K,​V>
extends java.lang.Object
implements java.io.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
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static java.lang.Object FREE_KEY  
      private java.lang.Object[] m_data_
      Keys and values
      private float m_fillFactor_
      Fill factor, must be between (0 and 1)
      private int m_mask_
      Mask to calculate the original position
      private int m_mask2_
      Mask to wrap the actual array pointer
      private int m_size_
      Current map size
      private int m_threshold_
      We will resize a map once it reaches this size
      private static java.lang.Object REMOVED_KEY  

    • Constructor Summary

      Constructors 
      Constructor Description
      FastHashMap()  
      FastHashMap​(int size, float fillFactor)  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      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 ).
      void clear()
      Clears the map, reuses the data structure by clearing it out.
      V get​(K key)  
      private int getStartIndex​(java.lang.Object key)  
      java.util.List<K> keys()  
      static long nextPowerOfTwo​(long x)
      Return the least power of two greater than or equal to the specified value.
      V put​(K key, V value)  
      private void readObject​(java.io.ObjectInputStream aInputStream)
      We have to overwrite the import due to the use of static object as marker
      private void rehash​(int newCapacity)  
      V remove​(K key)  
      int size()  
      java.util.List<V> values()  
      private void writeObject​(java.io.ObjectOutputStream aOutputStream)
      We have to overwrite the export due to the use of static object as marker

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • FREE_KEY

        private static final java.lang.Object FREE_KEY

      • REMOVED_KEY

        private static final java.lang.Object REMOVED_KEY

      • m_data_

        private java.lang.Object[] m_data_
        Keys and values

      • m_fillFactor_

        private final float m_fillFactor_
        Fill factor, must be between (0 and 1)

      • m_threshold_

        private int m_threshold_
        We will resize a map once it reaches this size

      • m_size_

        private int m_size_
        Current map size

      • m_mask_

        private int m_mask_
        Mask to calculate the original position

      • m_mask2_

        private int m_mask2_
        Mask to wrap the actual array pointer

    • Constructor Detail

      • FastHashMap

        public FastHashMap()

      • FastHashMap

        public FastHashMap​(int size,
                   float fillFactor)

    • Method Detail

      • get

        public V get​(K key)

      • put

        public V put​(K key,
             V value)

      • remove

        public V remove​(K key)

      • size

        public int size()

      • rehash

        private void rehash​(int newCapacity)

      • keys

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

      • values

        public java.util.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!

      • getStartIndex

        private int getStartIndex​(java.lang.Object key)

      • 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:
        java.lang.IllegalArgumentException - if the necessary size is larger than 230.

      • readObject

        private void readObject​(java.io.ObjectInputStream aInputStream)
                 throws java.lang.ClassNotFoundException,
                        java.io.IOException
        We have to overwrite the import due to the use of static object as marker
        Parameters:
        aInputStream - the inputstream to read from
        Throws:
        java.io.IOException - when the reading from the source fails
        java.lang.ClassNotFoundException - in case we cannot restore a class

      • writeObject

        private void writeObject​(java.io.ObjectOutputStream aOutputStream)
                  throws java.io.IOException
        We have to overwrite the export due to the use of static object as marker
        Parameters:
        aOutputStream - the stream to write to
        Throws:
        java.io.IOException - when a problem during writing occurs