gnu.trove

Class THashMap

public class THashMap extends TObjectHash implements Map, Serializable

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 1.15 2003/03/23 04:06:59 ericdf Exp $

Author: Eric D. Friedman

Nested Class Summary
classTHashMap.Entry
protected classTHashMap.EntryView
a view onto the entries of the map.
static classTHashMap.EqProcedure
classTHashMap.HashProcedure
protected classTHashMap.KeyView
a view onto the keys of the map.
protected classTHashMap.ValueView
a view onto the values of the map.
Field Summary
protected Object[]_values
the values of the map
Constructor Summary
THashMap()
Creates a new THashMap instance with the default capacity and load factor.
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.
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.
Method Summary
voidclear()
Empties the map.
Objectclone()
booleancontainsKey(Object key)
checks for the present of key in the keys of the map.
booleancontainsValue(Object val)
checks for the presence of val in the values of the map.
SetentrySet()
Returns a Set view on the entries of the map.
booleanequals(Object other)
Compares this map with another map for equality of their stored entries.
booleanforEachEntry(TObjectObjectProcedure procedure)
Executes procedure for each key/value entry in the map.
booleanforEachKey(TObjectProcedure procedure)
Executes procedure for each key in the map.
booleanforEachValue(TObjectProcedure procedure)
Executes procedure for each value in the map.
Objectget(Object key)
retrieves the value for key
inthashCode()
SetkeySet()
returns a Set view on the keys of the map.
Objectput(Object key, Object value)
Inserts a key/value pair into the map.
voidputAll(Map map)
copies the key/value mappings in map into this map.
voidreadObject(ObjectInputStream stream)
protected voidrehash(int newCapacity)
rehashes the map to the new capacity.
Objectremove(Object key)
Deletes a key/value pair from the map.
protected voidremoveAt(int index)
removes the mapping at index from the map.
booleanretainEntries(TObjectObjectProcedure procedure)
Retains only those entries in the map for which the procedure returns a true value.
protected intsetUp(int initialCapacity)
initialize the value array of the map.
voidtransformValues(TObjectFunction function)
Transform the values in this map using function.
Collectionvalues()
Returns a view on the values of the map.
voidwriteObject(ObjectOutputStream stream)

Field Detail

_values

protected transient Object[] _values
the values of the map

Constructor Detail

THashMap

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

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.

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.

Method Detail

clear

public void clear()
Empties the map.

clone

public Object 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 Object 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 Object put(Object key, Object 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(Map map)
copies the key/value mappings in map into this map.

Parameters: map a Map value

readObject

private void readObject(ObjectInputStream stream)

rehash

protected void rehash(int newCapacity)
rehashes the map to the new capacity.

Parameters: newCapacity an int value

remove

public Object 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

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

writeObject

private void writeObject(ObjectOutputStream stream)