gnu.trove

Class THashMap<K,V>

Implemented Interfaces:
Externalizable, Map

public class THashMap<K,V>
extends TObjectHash
implements Map, Externalizable

An implementation of the Map interface which uses an open addressed hash table to store its contents. Created: Sun Nov 4 08:52:45 2001
Version:
$Id: THashMap.java,v 1.26 2007/06/29 20:03:10 robeden Exp $
Author:
Eric D. Friedman

Nested Class Summary

protected class
THashMap.EntryView
a view onto the entries of the map.
protected class
THashMap.KeyView
a view onto the keys of the map.
protected class
THashMap.ValueView
a view onto the values of the map.

Field Summary

protected V[]
_values
the values of the map

Constructor Summary

THashMap()
Creates a new THashMap instance with the default capacity and load factor.
THashMap(Map map)
Creates a new THashMap instance which contains the key/value pairs in map.
THashMap(Map map, TObjectHashingStrategy strategy)
Creates a new THashMap instance which contains the key/value pairs in map.
THashMap(TObjectHashingStrategy strategy)
Creates a new THashMap instance with the default capacity and load factor.
THashMap(int initialCapacity)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the default load factor.
THashMap(int initialCapacity, TObjectHashingStrategy strategy)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the default load factor.
THashMap(int initialCapacity, float loadFactor)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the specified load factor.
THashMap(int initialCapacity, float loadFactor, TObjectHashingStrategy strategy)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the specified load factor.

Method Summary

void
clear()
Empties the map.
THashMap
clone()
boolean
containsKey(Object key)
checks for the present of key in the keys of the map.
boolean
containsValue(Object val)
checks for the presence of val in the values of the map.
Set>
entrySet()
Returns a Set view on the entries of the map.
boolean
equals(Object other)
Compares this map with another map for equality of their stored entries.
boolean
forEachEntry(TObjectObjectProcedure procedure)
Executes procedure for each key/value entry in the map.
boolean
forEachKey(TObjectProcedure procedure)
Executes procedure for each key in the map.
boolean
forEachValue(TObjectProcedure procedure)
Executes procedure for each value in the map.
V
get(Object key)
retrieves the value for key
int
hashCode()
Set
keySet()
returns a Set view on the keys of the map.
V
put(K key, V value)
Inserts a key/value pair into the map.
void
putAll(extends K, V> map)
copies the key/value mappings in map into this map.
void
readExternal(ObjectInput in)
protected void
rehash(int newCapacity)
rehashes the map to the new capacity.
V
remove(Object key)
Deletes a key/value pair from the map.
protected void
removeAt(int index)
removes the mapping at index from the map.
boolean
retainEntries(TObjectObjectProcedure procedure)
Retains only those entries in the map for which the procedure returns a true value.
protected int
setUp(int initialCapacity)
initialize the value array of the map.
String
toString()
void
transformValues(TObjectFunction function)
Transform the values in this map using function.
Collection
values()
Returns a view on the values of the map.
void
writeExternal(ObjectOutput out)

Field Details

_values

protected V[] _values
the values of the map

Constructor Details

THashMap

public THashMap()
Creates a new THashMap instance with the default capacity and load factor.

THashMap

public THashMap(Map map)
Creates a new THashMap instance which contains the key/value pairs in map.
Parameters:
map - a Map value

THashMap

public THashMap(Map map,
                TObjectHashingStrategy strategy)
Creates a new THashMap instance which contains the key/value pairs in map.
Parameters:
map - a Map value
strategy - used to compute hash codes and to compare objects.

THashMap

public THashMap(TObjectHashingStrategy strategy)
Creates a new THashMap instance with the default capacity and load factor.
Parameters:
strategy - used to compute hash codes and to compare objects.

THashMap

public THashMap(int initialCapacity)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the default load factor.
Parameters:
initialCapacity - an int value

THashMap

public THashMap(int initialCapacity,
                TObjectHashingStrategy strategy)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the default load factor.
Parameters:
initialCapacity - an int value
strategy - used to compute hash codes and to compare objects.

THashMap

public THashMap(int initialCapacity,
                float loadFactor)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the specified load factor.
Parameters:
initialCapacity - an int value
loadFactor - a float value

THashMap

public THashMap(int initialCapacity,
                float loadFactor,
                TObjectHashingStrategy strategy)
Creates a new THashMap instance with a prime capacity equal to or greater than initialCapacity and with the specified load factor.
Parameters:
initialCapacity - an int value
loadFactor - a float value
strategy - used to compute hash codes and to compare objects.

Method Details

clear

public void clear()
Empties the map.

clone

public THashMap clone()
Returns:
a shallow clone of this collection

containsKey

public boolean containsKey(Object key)
checks for the present of key in the keys of the map.
Parameters:
key - an Object value
Returns:
a boolean value

containsValue

public boolean containsValue(Object val)
checks for the presence of val in the values of the map.
Parameters:
val - an Object value
Returns:
a boolean value

entrySet

public Set> entrySet()
Returns a Set view on the entries of the map.
Returns:
a Set value

equals

public boolean equals(Object other)
Compares this map with another map for equality of their stored entries.
Parameters:
other - an Object value
Returns:
a boolean value

forEachEntry

public boolean forEachEntry(TObjectObjectProcedure procedure)
Executes procedure for each key/value entry in the map.
Parameters:
procedure - a TObjectObjectProcedure value
Returns:
false if the loop over the entries terminated because the procedure returned false for some entry.

forEachKey

public boolean forEachKey(TObjectProcedure procedure)
Executes procedure for each key in the map.
Parameters:
procedure - a TObjectProcedure value
Returns:
false if the loop over the keys terminated because the procedure returned false for some key.

forEachValue

public boolean forEachValue(TObjectProcedure procedure)
Executes procedure for each value in the map.
Parameters:
procedure - a TObjectProcedure value
Returns:
false if the loop over the values terminated because the procedure returned false for some value.

get

public V get(Object key)
retrieves the value for key
Parameters:
key - an Object value
Returns:
the value of key or null if no such mapping exists.

hashCode

public int hashCode()

keySet

public Set keySet()
returns a Set view on the keys of the map.
Returns:
a Set value

put

public V put(K key,
             V value)
Inserts a key/value pair into the map.
Parameters:
key - an Object value
value - an Object value
Returns:
the previous value associated with key, or null if none was found.

putAll

public void putAll(extends K,
                   V> map)
copies the key/value mappings in map into this map.
Parameters:
map - a Map value

readExternal

public void readExternal(ObjectInput in)
            throws IOException,
                   ClassNotFoundException

rehash

protected void rehash(int newCapacity)
rehashes the map to the new capacity.
Parameters:
newCapacity - an int value

remove

public V remove(Object key)
Deletes a key/value pair from the map.
Parameters:
key - an Object value
Returns:
an Object value

removeAt

protected void removeAt(int index)
removes the mapping at index from the map.
Parameters:
index - an int value

retainEntries

public boolean retainEntries(TObjectObjectProcedure procedure)
Retains only those entries in the map for which the procedure returns a true value.
Parameters:
procedure - determines which entries to keep
Returns:
true if the map was modified.

setUp

protected int setUp(int initialCapacity)
initialize the value array of the map.
Parameters:
initialCapacity - an int value
Returns:
an int value

toString

public String toString()

transformValues

public void transformValues(TObjectFunction function)
Transform the values in this map using function.
Parameters:
function - a TObjectFunction value

values

public Collection values()
Returns a view on the values of the map.
Returns:
a Collection value

writeExternal

public void writeExternal(ObjectOutput out)
            throws IOException

GNU Trove is copyright B) 2001-2007 Eric D. Friedman. All Rights Reserved.