org.hibernate.util

Class FastHashMap

Implemented Interfaces:
Map, Serializable

public final class FastHashMap
extends java.lang.Object
implements Map, Serializable

A customized implementation of java.util.HashMap designed to operate in a multithreaded environment where the large majority of method calls are read-only, instead of structural changes. Read calls are non-synchronized and write calls perform the following steps:

NOTE: If you are creating and accessing a HashMap only within a single thread, you should use java.util.HashMap directly (with no synchronization), for maximum performance.

Constructor Summary

FastHashMap()
Construct a an empty map.
FastHashMap(Map map)
Construct a new map with the same mappings as the specified map.
FastHashMap(int capacity)
Construct an empty map with the specified capacity.
FastHashMap(int capacity, float factor)
Construct an empty map with the specified capacity and load factor.

Method Summary

void
clear()
Remove all mappings from this map.
Object
clone()
Return a shallow copy of this FastHashMap instance.
boolean
containsKey(Object key)
Return true if this map contains a mapping for the specified key.
boolean
containsValue(Object value)
Return true if this map contains one or more keys mapping to the specified value.
Set
entrySet()
Return a collection view of the mappings contained in this map.
boolean
equals(Object o)
Compare the specified object with this list for equality.
Object
get(Object key)
Return the value to which this map maps the specified key.
int
hashCode()
Return the hash code value for this map.
boolean
isEmpty()
Return true if this map contains no mappings.
Set
keySet()
Return a set view of the keys contained in this map.
Object
put(Object key, Object value)
Associate the specified value with the specified key in this map.
void
putAll(Map in)
Copy all of the mappings from the specified map to this one, replacing any mappings with the same keys.
Object
remove(Object key)
Remove any mapping for this key, and return any previously mapped value.
int
size()
Return the number of key-value mappings in this map.
String
toString()
Collection
values()
Return a collection view of the values contained in this map.

Constructor Details

FastHashMap

public FastHashMap()
Construct a an empty map.

FastHashMap

public FastHashMap(Map map)
Construct a new map with the same mappings as the specified map.
Parameters:
map - The map whose mappings are to be copied

FastHashMap

public FastHashMap(int capacity)
Construct an empty map with the specified capacity.
Parameters:
capacity - The initial capacity of the empty map

FastHashMap

public FastHashMap(int capacity,
                   float factor)
Construct an empty map with the specified capacity and load factor.
Parameters:
capacity - The initial capacity of the empty map
factor - The load factor of the new map

Method Details

clear

public void clear()
Remove all mappings from this map.

clone

public Object clone()
Return a shallow copy of this FastHashMap instance. The keys and values themselves are not copied.

containsKey

public boolean containsKey(Object key)
Return true if this map contains a mapping for the specified key.
Parameters:
key - Key to be searched for

containsValue

public boolean containsValue(Object value)
Return true if this map contains one or more keys mapping to the specified value.
Parameters:
value - Value to be searched for

entrySet

public Set entrySet()
Return a collection view of the mappings contained in this map. Each element in the returned collection is a Map.Entry.

equals

public boolean equals(Object o)
Compare the specified object with this list for equality. This implementation uses exactly the code that is used to define the list equals function in the documentation for the Map.equals method.
Parameters:
o - Object to be compared to this list

get

public Object get(Object key)
Return the value to which this map maps the specified key. Returns null if the map contains no mapping for this key, or if there is a mapping with a value of null. Use the containsKey() method to disambiguate these cases.
Parameters:
key - Key whose value is to be returned

hashCode

public int hashCode()
Return the hash code value for this map. This implementation uses exactly the code that is used to define the list hash function in the documentation for the Map.hashCode method.

isEmpty

public boolean isEmpty()
Return true if this map contains no mappings.

keySet

public Set keySet()
Return a set view of the keys contained in this map.

put

public Object put(Object key,
                  Object value)
Associate the specified value with the specified key in this map. If the map previously contained a mapping for this key, the old value is replaced and returned.
Parameters:
key - The key with which the value is to be associated
value - The value to be associated with this key

putAll

public void putAll(Map in)
Copy all of the mappings from the specified map to this one, replacing any mappings with the same keys.
Parameters:
in - Map whose mappings are to be copied

remove

public Object remove(Object key)
Remove any mapping for this key, and return any previously mapped value.
Parameters:
key - Key whose mapping is to be removed

size

public int size()
Return the number of key-value mappings in this map.

toString

public String toString()

values

public Collection values()
Return a collection view of the values contained in this map.