PCJ API
Version 1.2

bak.pcj.map
Class CharKeyByteChainedHashMap

java.lang.Object
  extended bybak.pcj.map.AbstractCharKeyByteMap
      extended bybak.pcj.map.CharKeyByteChainedHashMap
All Implemented Interfaces:
CharKeyByteMap, Cloneable, Serializable

public class CharKeyByteChainedHashMap
extends AbstractCharKeyByteMap
implements CharKeyByteMap, Cloneable, Serializable

This class represents chained hash table based maps from char values to byte values.

Since:
1.0
See Also:
CharKeyByteOpenHashMap, Map, Serialized Form

Field Summary
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.
static double DEFAULT_LOAD_FACTOR
          The default load factor of this map.
 
Constructor Summary
CharKeyByteChainedHashMap()
          Creates a new hash map with capacity 11, a relative growth factor of 1.0, and a load factor of 75%.
CharKeyByteChainedHashMap(CharHashFunction keyhash)
          Creates a new hash map with capacity 11, a relative growth factor of 1.0, and a load factor of 75%.
CharKeyByteChainedHashMap(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.
CharKeyByteChainedHashMap(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%.
CharKeyByteChainedHashMap(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.
CharKeyByteChainedHashMap(CharHashFunction keyhash, int capacity, double loadFactor, double growthFactor)
          Creates a new hash map with a specified capacity, load factor, and relative growth factor.
CharKeyByteChainedHashMap(CharHashFunction keyhash, int capacity, double loadFactor, int growthChunk)
          Creates a new hash map with a specified capacity, load factor, and absolute growth factor.
CharKeyByteChainedHashMap(CharKeyByteMap map)
          Creates a new hash map with the same mappings as a specified map.
CharKeyByteChainedHashMap(double loadFactor)
          Creates a new hash map with a capacity of 11, a relative growth factor of 1.0, and a specified load factor.
CharKeyByteChainedHashMap(int capacity)
          Creates a new hash map with a specified capacity, a relative growth factor of 1.0, and a load factor of 75%.
CharKeyByteChainedHashMap(int capacity, double loadFactor)
          Creates a new hash map with a specified capacity and load factor, and a relative growth factor of 1.0.
CharKeyByteChainedHashMap(int capacity, double loadFactor, double growthFactor)
          Creates a new hash map with a specified capacity, load factor, and relative growth factor.
CharKeyByteChainedHashMap(int capacity, double loadFactor, int growthChunk)
          Creates a new hash map with a specified capacity, load factor, and absolute growth factor.
 
Method Summary
 void clear()
          Clears this map.
 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(byte value)
          Indicates whether this map contains a mapping to a specified value.
 CharKeyByteMapIterator entries()
          Returns an iterator over the entries of this map.
 byte 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.
 byte lget()
          Returns the last value corresponding to a positive result from containsKey(char).
 byte put(char key, byte value)
          Adds a mapping from a specified key to a specified value to this map.
 byte remove(char key)
          Removes the mapping from a specified key from this map.
 int size()
          Returns the size of this map.
 byte tget(char key)
          Maps a specified key to a value.
 ByteCollection values()
          Returns a collection view of the values in this map.
 
Methods inherited from class bak.pcj.map.AbstractCharKeyByteMap
equals, hashCode, putAll, toString, trimToSize
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface bak.pcj.map.CharKeyByteMap
equals, hashCode, putAll, trimToSize
 

Field Detail

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
Constructor Detail

CharKeyByteChainedHashMap

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


CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(CharKeyByteMap 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:
NullPointerException - if map is null.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative; if loadFactor is not positive.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthFactor is not positive.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthChunk is not positive;

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
NullPointerException - if keyhash is null.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative.
NullPointerException - if keyhash is null.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative.
NullPointerException - if keyhash is null.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative; if loadFactor is not positive.
NullPointerException - if keyhash is null.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthFactor is not positive.
NullPointerException - if keyhash is null.

CharKeyByteChainedHashMap

public CharKeyByteChainedHashMap(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:
IllegalArgumentException - if capacity is negative; if loadFactor is not positive; if growthChunk is not positive;
NullPointerException - if keyhash is null.
Method Detail

keySet

public CharSet keySet()
Description copied from interface: CharKeyByteMap
Returns a set view of the keys of this map. Removals from the returned set removes the corresponding entries in this map. Changes to the map are reflected in the set.

Specified by:
keySet in interface CharKeyByteMap
Returns:
a set view of the keys of this map.

lget

public byte lget()
Description copied from interface: CharKeyByteMap
Returns the last value corresponding to a positive result from containsKey(char). This is useful for checking checking the existence of a mapping while avoiding two lookups on the same key.

Specified by:
lget in interface CharKeyByteMap
Returns:
the value corresponding to the key from the last invokation of containsKey(char).
See Also:
CharKeyByteMap.get(char), CharKeyByteMap.tget(char), CharKeyByteMap.containsKey(char)

put

public byte put(char key,
                byte value)
Description copied from interface: CharKeyByteMap
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 CharKeyByteMap
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 if a mapping from the specified key already existed in this map; otherwise returns a default value as specified by the MapDefaults class.
See Also:
MapDefaults

values

public ByteCollection values()
Description copied from interface: CharKeyByteMap
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 CharKeyByteMap
Returns:
a collection view of the values in this map.

clone

public Object clone()
Returns a clone of this hash map.

Returns:
a clone of this hash map.
Since:
1.1

entries

public CharKeyByteMapIterator entries()
Description copied from interface: CharKeyByteMap
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 CharKeyByteMap
Returns:
an iterator over the entries of this map.

clear

public void clear()
Description copied from interface: CharKeyByteMap
Clears this map.

Specified by:
clear in interface CharKeyByteMap
Overrides:
clear in class AbstractCharKeyByteMap

containsKey

public boolean containsKey(char key)
Description copied from interface: CharKeyByteMap
Indicates whether this map contains a mapping from a specified key. If the key is contained in this map, a succeeding call to lget() will return the corresponding value.

Specified by:
containsKey in interface CharKeyByteMap
Overrides:
containsKey in class AbstractCharKeyByteMap

containsValue

public boolean containsValue(byte value)
Description copied from interface: CharKeyByteMap
Indicates whether this map contains a mapping to a specified value.

Specified by:
containsValue in interface CharKeyByteMap
Overrides:
containsValue in class AbstractCharKeyByteMap

get

public byte get(char key)
Description copied from interface: CharKeyByteMap
Maps a specified key to a value. Returns a default value as specified by the MapDefaults class if no mapping exists for the specified key.

Specified by:
get in interface CharKeyByteMap
Overrides:
get in class AbstractCharKeyByteMap

isEmpty

public boolean isEmpty()
Description copied from interface: CharKeyByteMap
Indicates whether this map is empty.

Specified by:
isEmpty in interface CharKeyByteMap
Overrides:
isEmpty in class AbstractCharKeyByteMap

remove

public byte remove(char key)
Description copied from interface: CharKeyByteMap
Removes the mapping from a specified key from this map.

Specified by:
remove in interface CharKeyByteMap
Overrides:
remove in class AbstractCharKeyByteMap

size

public int size()
Description copied from interface: CharKeyByteMap
Returns the size of this map. The size is defined as the number of mappings from keys to values.

Specified by:
size in interface CharKeyByteMap
Overrides:
size in class AbstractCharKeyByteMap

tget

public byte tget(char key)
Description copied from interface: CharKeyByteMap
Maps a specified key to a value. This method should be used when the key is known to be in the map.

Specified by:
tget in interface CharKeyByteMap
Overrides:
tget in class AbstractCharKeyByteMap

PCJ API
Version 1.2

Report a bug or request a feature.
Further information on the development and latest release of PCJ can be found at the project homepage.

Primitive Collections for Java is released under the GNU Lesser General Public License.
Copyright © 2002, 2003 Søren Bak. All Rights Reserved.

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