Class CharKeyOpenHashMap

  • All Implemented Interfaces:
    CharKeyMap, java.io.Serializable, java.lang.Cloneable

    public class CharKeyOpenHashMap
    extends AbstractCharKeyMap
    implements CharKeyMap, java.lang.Cloneable, java.io.Serializable
    This class represents open addressing hash table based maps from char values to objects.
    Since:
    1.0
    Version:
    1.3 21-08-2003 19:45
    See Also:
    CharKeyChainedHashMap, Map, Serialized Form
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private CharSet ckeys
      A set view of the keys of this map.
      private java.util.Collection cvalues
      A collection view of the values of this map.
      static int DEFAULT_CAPACITY
      The default capacity of this map.
      static int DEFAULT_GROWTH_CHUNK
      The default chunk size with which to increase the capacity of this map.
      static double DEFAULT_GROWTH_FACTOR
      The default factor with which to increase the capacity of this map.
      private static int DEFAULT_GROWTH_POLICY
      The default growth policy of this map.
      static double DEFAULT_LOAD_FACTOR
      The default load factor of this map.
      private static byte EMPTY  
      private int expandAt
      The next size at which to expand the data[].
      private static int GROWTH_POLICY_ABSOLUTE
      Constant indicating absolute growth policy.
      private static int GROWTH_POLICY_RELATIVE
      Constant indicating relative growth policy.
      private int growthChunk
      The growth chunk size of this map, if the growth policy is absolute.
      private double growthFactor
      The growth factor of this map, if the growth policy is relative.
      private int growthPolicy
      The growth policy of this map (0 is relative growth, 1 is absolute growth).
      private CharHashFunction keyhash
      The hash function used to hash keys in this map.
      private char[] keys
      The keys of this map.
      private double loadFactor
      The load factor of this map.
      private static byte OCCUPIED  
      private static byte REMOVED  
      private int size
      The size of this map.
      private byte[] states
      The states of each cell in the keys[] and values[].
      private int used
      The number of entries in use (removed or occupied).
      private java.lang.Object[] values
      The values of this map.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
        CharKeyOpenHashMap()
      Creates a new hash map with capacity 11, a relative growth factor of 1.0, and a load factor of 75%.
        CharKeyOpenHashMap​(double loadFactor)
      Creates a new hash map with a capacity of 11, a relative growth factor of 1.0, and a specified load factor.
        CharKeyOpenHashMap​(int capacity)
      Creates a new hash map with a specified capacity, a relative growth factor of 1.0, and a load factor of 75%.
        CharKeyOpenHashMap​(int capacity, double loadFactor)
      Creates a new hash map with a specified capacity and load factor, and a relative growth factor of 1.0.
        CharKeyOpenHashMap​(int capacity, double loadFactor, double growthFactor)
      Creates a new hash map with a specified capacity, load factor, and relative growth factor.
        CharKeyOpenHashMap​(int capacity, double loadFactor, int growthChunk)
      Creates a new hash map with a specified capacity, load factor, and absolute growth factor.
      private CharKeyOpenHashMap​(int capacity, int growthPolicy, double growthFactor, int growthChunk, double loadFactor)  
        CharKeyOpenHashMap​(CharHashFunction keyhash)
      Creates a new hash map with capacity 11, a relative growth factor of 1.0, and a load factor of 75%.
        CharKeyOpenHashMap​(CharHashFunction keyhash, double loadFactor)
      Creates a new hash map with a capacity of 11, a relative growth factor of 1.0, and a specified load factor.
        CharKeyOpenHashMap​(CharHashFunction keyhash, int capacity)
      Creates a new hash map with a specified capacity, a relative growth factor of 1.0, and a load factor of 75%.
        CharKeyOpenHashMap​(CharHashFunction keyhash, int capacity, double loadFactor)
      Creates a new hash map with a specified capacity and load factor, and a relative growth factor of 1.0.
        CharKeyOpenHashMap​(CharHashFunction keyhash, int capacity, double loadFactor, double growthFactor)
      Creates a new hash map with a specified capacity, load factor, and relative growth factor.
        CharKeyOpenHashMap​(CharHashFunction keyhash, int capacity, double loadFactor, int growthChunk)
      Creates a new hash map with a specified capacity, load factor, and absolute growth factor.
      private CharKeyOpenHashMap​(CharHashFunction keyhash, int capacity, int growthPolicy, double growthFactor, int growthChunk, double loadFactor)  
        CharKeyOpenHashMap​(CharKeyMap map)
      Creates a new hash map with the same mappings as a specified map.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clear()
      Clears this map.
      java.lang.Object clone()
      Returns a clone of this hash map.
      boolean containsKey​(char key)
      Indicates whether this map contains a mapping from a specified key.
      boolean containsValue​(java.lang.Object value)
      Indicates whether this map contains a mapping to a specified value.
      private void ensureCapacity​(int elements)  
      CharKeyMapIterator entries()
      Returns an iterator over the entries of this map.
      java.lang.Object get​(char key)
      Maps a specified key to a value.
      boolean isEmpty()
      Indicates whether this map is empty.
      CharSet keySet()
      Returns a set view of the keys of this map.
      java.lang.Object put​(char key, java.lang.Object value)
      Adds a mapping from a specified key to a specified value to this map.
      private void readObject​(java.io.ObjectInputStream s)  
      java.lang.Object remove​(char key)
      Removes the mapping from a specified key from this map.
      int size()
      Returns the size of this map.
      java.util.Collection values()
      Returns a collection view of the values in this map.
      private void writeObject​(java.io.ObjectOutputStream s)  
      • Methods inherited from class java.lang.Object

        finalize, getClass, notify, notifyAll, wait, wait, wait
    • Field Detail

      • GROWTH_POLICY_RELATIVE

        private static final int GROWTH_POLICY_RELATIVE
        Constant indicating relative growth policy.
        See Also:
        Constant Field Values
      • GROWTH_POLICY_ABSOLUTE

        private static final int GROWTH_POLICY_ABSOLUTE
        Constant indicating absolute growth policy.
        See Also:
        Constant Field Values
      • DEFAULT_GROWTH_FACTOR

        public static final double DEFAULT_GROWTH_FACTOR
        The default factor with which to increase the capacity of this map.
        See Also:
        Constant Field Values
      • DEFAULT_GROWTH_CHUNK

        public static final int DEFAULT_GROWTH_CHUNK
        The default chunk size with which to increase the capacity of this map.
        See Also:
        Constant Field Values
      • DEFAULT_CAPACITY

        public static final int DEFAULT_CAPACITY
        The default capacity of this map.
        See Also:
        Constant Field Values
      • DEFAULT_LOAD_FACTOR

        public static final double DEFAULT_LOAD_FACTOR
        The default load factor of this map.
        See Also:
        Constant Field Values
      • keyhash

        private CharHashFunction keyhash
        The hash function used to hash keys in this map.
      • size

        private int size
        The size of this map.
      • keys

        private transient char[] keys
        The keys of this map. Contains key values directly. Due to the use of a secondary hash function, the length of this array must be a prime.
      • values

        private transient java.lang.Object[] values
        The values of this map. Contains values directly. Due to the use of a secondary hash function, the length of this array must be a prime.
      • states

        private transient byte[] states
        The states of each cell in the keys[] and values[].
      • used

        private transient int used
        The number of entries in use (removed or occupied).
      • growthPolicy

        private int growthPolicy
        The growth policy of this map (0 is relative growth, 1 is absolute growth).
      • growthFactor

        private double growthFactor
        The growth factor of this map, if the growth policy is relative.
      • growthChunk

        private int growthChunk
        The growth chunk size of this map, if the growth policy is absolute.
      • loadFactor

        private double loadFactor
        The load factor of this map.
      • expandAt

        private int expandAt
        The next size at which to expand the data[].
      • ckeys

        private transient CharSet ckeys
        A set view of the keys of this map.
      • cvalues

        private transient java.util.Collection cvalues
        A collection view of the values of this map.
    • Constructor Detail

      • CharKeyOpenHashMap

        private CharKeyOpenHashMap​(CharHashFunction keyhash,
                                   int capacity,
                                   int growthPolicy,
                                   double growthFactor,
                                   int growthChunk,
                                   double loadFactor)
      • CharKeyOpenHashMap

        private CharKeyOpenHashMap​(int capacity,
                                   int growthPolicy,
                                   double growthFactor,
                                   int growthChunk,
                                   double loadFactor)
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap()
        Creates a new hash map with capacity 11, a relative growth factor of 1.0, and a load factor of 75%.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(CharKeyMap map)
        Creates a new hash map with the same mappings as a specified map.
        Parameters:
        map - the map whose mappings to put into the new map.
        Throws:
        java.lang.NullPointerException - if map is null.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(int capacity)
        Creates a new hash map with a specified capacity, a relative growth factor of 1.0, and a load factor of 75%.
        Parameters:
        capacity - the initial capacity of the map.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(double loadFactor)
        Creates a new hash map with a capacity of 11, a relative growth factor of 1.0, and a specified load factor.
        Parameters:
        loadFactor - the load factor of the map.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(int capacity,
                                  double loadFactor)
        Creates a new hash map with a specified capacity and load factor, and a relative growth factor of 1.0.
        Parameters:
        capacity - the initial capacity of the map.
        loadFactor - the load factor of the map.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(int capacity,
                                  double loadFactor,
                                  double growthFactor)
        Creates a new hash map with a specified capacity, load factor, and relative growth factor.

        The map capacity increases to capacity()*(1+growthFactor). This strategy is good for avoiding many capacity increases, but the amount of wasted memory is approximately the size of the map.

        Parameters:
        capacity - the initial capacity of the map.
        loadFactor - the load factor of the map.
        growthFactor - the relative amount with which to increase the the capacity when a capacity increase is needed.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthFactor is not positive.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(int capacity,
                                  double loadFactor,
                                  int growthChunk)
        Creates a new hash map with a specified capacity, load factor, and absolute growth factor.

        The map capacity increases to capacity()+growthChunk. This strategy is good for avoiding wasting memory. However, an overhead is potentially introduced by frequent capacity increases.

        Parameters:
        capacity - the initial capacity of the map.
        loadFactor - the load factor of the map.
        growthChunk - the absolute amount with which to increase the the capacity when a capacity increase is needed.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthChunk is not positive.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(CharHashFunction keyhash)
        Creates a new hash map with capacity 11, a relative growth factor of 1.0, and a load factor of 75%.
        Parameters:
        keyhash - the hash function to use when hashing keys.
        Throws:
        java.lang.NullPointerException - if keyhash is null.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(CharHashFunction keyhash,
                                  int capacity)
        Creates a new hash map with a specified capacity, a relative growth factor of 1.0, and a load factor of 75%.
        Parameters:
        keyhash - the hash function to use when hashing keys.
        capacity - the initial capacity of the map.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative.
        java.lang.NullPointerException - if keyhash is null.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(CharHashFunction keyhash,
                                  double loadFactor)
        Creates a new hash map with a capacity of 11, a relative growth factor of 1.0, and a specified load factor.
        Parameters:
        keyhash - the hash function to use when hashing keys.
        loadFactor - the load factor of the map.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive.
        java.lang.NullPointerException - if keyhash is null.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(CharHashFunction keyhash,
                                  int capacity,
                                  double loadFactor)
        Creates a new hash map with a specified capacity and load factor, and a relative growth factor of 1.0.
        Parameters:
        keyhash - the hash function to use when hashing keys.
        capacity - the initial capacity of the map.
        loadFactor - the load factor of the map.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive.
        java.lang.NullPointerException - if keyhash is null.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(CharHashFunction keyhash,
                                  int capacity,
                                  double loadFactor,
                                  double growthFactor)
        Creates a new hash map with a specified capacity, load factor, and relative growth factor.

        The map capacity increases to capacity()*(1+growthFactor). This strategy is good for avoiding many capacity increases, but the amount of wasted memory is approximately the size of the map.

        Parameters:
        keyhash - the hash function to use when hashing keys.
        capacity - the initial capacity of the map.
        loadFactor - the load factor of the map.
        growthFactor - the relative amount with which to increase the the capacity when a capacity increase is needed.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthFactor is not positive.
        java.lang.NullPointerException - if keyhash is null.
      • CharKeyOpenHashMap

        public CharKeyOpenHashMap​(CharHashFunction keyhash,
                                  int capacity,
                                  double loadFactor,
                                  int growthChunk)
        Creates a new hash map with a specified capacity, load factor, and absolute growth factor.

        The map capacity increases to capacity()+growthChunk. This strategy is good for avoiding wasting memory. However, an overhead is potentially introduced by frequent capacity increases.

        Parameters:
        keyhash - the hash function to use when hashing keys.
        capacity - the initial capacity of the map.
        loadFactor - the load factor of the map.
        growthChunk - the absolute amount with which to increase the the capacity when a capacity increase is needed.
        Throws:
        java.lang.IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthChunk is not positive.
        java.lang.NullPointerException - if keyhash is null.
    • Method Detail

      • ensureCapacity

        private void ensureCapacity​(int elements)
      • keySet

        public CharSet keySet()
        Description copied from interface: CharKeyMap
        Returns a set view of the keys of this map. The set is not directly modifiable, but changes to the map are reflected in the set.
        Specified by:
        keySet in interface CharKeyMap
        Returns:
        a set view of the keys of this map.
      • put

        public java.lang.Object put​(char key,
                                    java.lang.Object value)
        Description copied from interface: CharKeyMap
        Adds a mapping from a specified key to a specified value to this map. If a mapping already exists for the specified key it is overwritten by the new mapping.
        Specified by:
        put in interface CharKeyMap
        Parameters:
        key - the key of the mapping to add to this map.
        value - the value of the mapping to add to this map.
        Returns:
        the old value (which can be null) if a mapping from the specified key already existed in this map; returns null otherwise.
      • values

        public java.util.Collection values()
        Description copied from interface: CharKeyMap
        Returns a collection view of the values in this map. The collection is not modifiable, but changes to the map are reflected in the collection.
        Specified by:
        values in interface CharKeyMap
        Returns:
        a collection view of the values in this map.
      • clone

        public java.lang.Object clone()
        Returns a clone of this hash map.
        Overrides:
        clone in class java.lang.Object
        Returns:
        a clone of this hash map.
        Since:
        1.1
      • entries

        public CharKeyMapIterator entries()
        Description copied from interface: CharKeyMap
        Returns an iterator over the entries of this map. It is possible to remove entries from this map using the iterator provided that the concrete map supports removal of entries.
        Specified by:
        entries in interface CharKeyMap
        Returns:
        an iterator over the entries of this map.
      • containsKey

        public boolean containsKey​(char key)
        Description copied from interface: CharKeyMap
        Indicates whether this map contains a mapping from a specified key.
        Specified by:
        containsKey in interface CharKeyMap
        Overrides:
        containsKey in class AbstractCharKeyMap
        Parameters:
        key - the key to test for.
        Returns:
        true if this map contains a mapping from the specified key; returns false otherwise.
      • containsValue

        public boolean containsValue​(java.lang.Object value)
        Description copied from interface: CharKeyMap
        Indicates whether this map contains a mapping to a specified value.
        Specified by:
        containsValue in interface CharKeyMap
        Overrides:
        containsValue in class AbstractCharKeyMap
        Parameters:
        value - the value to test for.
        Returns:
        true if this map contains at least one mapping to the specified value; returns false otherwise.
      • get

        public java.lang.Object get​(char key)
        Description copied from interface: CharKeyMap
        Maps a specified key to a value.
        Specified by:
        get in interface CharKeyMap
        Overrides:
        get in class AbstractCharKeyMap
        Parameters:
        key - the key to map to a value.
        Returns:
        the value that the specified key maps to; returns null, if no mapping exists for the specified key.
      • isEmpty

        public boolean isEmpty()
        Description copied from interface: CharKeyMap
        Indicates whether this map is empty.
        Specified by:
        isEmpty in interface CharKeyMap
        Overrides:
        isEmpty in class AbstractCharKeyMap
        Returns:
        true if this map is empty; returns false otherwise.
      • remove

        public java.lang.Object remove​(char key)
        Description copied from interface: CharKeyMap
        Removes the mapping from a specified key from this map.
        Specified by:
        remove in interface CharKeyMap
        Overrides:
        remove in class AbstractCharKeyMap
        Parameters:
        key - the key whose mapping to remove from this map.
        Returns:
        the old value (which can be null) if a mapping from the specified key already existed in this map; returns null otherwise.
      • size

        public int size()
        Description copied from interface: CharKeyMap
        Returns the size of this map. The size is defined as the number of mappings from keys to values.
        Specified by:
        size in interface CharKeyMap
        Overrides:
        size in class AbstractCharKeyMap
        Returns:
        the size of this map.
      • writeObject

        private void writeObject​(java.io.ObjectOutputStream s)
                          throws java.io.IOException
        Throws:
        java.io.IOException
        Since:
        1.1
      • readObject

        private void readObject​(java.io.ObjectInputStream s)
                         throws java.io.IOException,
                                java.lang.ClassNotFoundException
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException
        Since:
        1.1