Class FastCopyHashMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.jboss.logmanager.FastCopyHashMap<K,V>

All Implemented Interfaces:

Serializable, Cloneable, Map<K,V>

class FastCopyHashMap<K,V>
extends AbstractMap<K,V>
implements Map<K,V>, Cloneable, Serializable

A HashMap that is optimized for fast shallow copies. If the copy-ctor is passed another FastCopyHashMap, or clone is called on this map, the shallow copy can be performed using little more than a single array copy. In order to accomplish this, immutable objects must be used internally, so update operations result in slightly more object churn than HashMap. Note: It is very important to use a smaller load factor than you normally would for HashMap, since the implementation is open-addressed with linear probing. With a 50% load-factor a get is expected to return in only 2 probes. However, a 90% load-factor is expected to return in around 50 probes.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	FastCopyHashMap.Entry<K,V>
private class	FastCopyHashMap.EntryIterator
private class	FastCopyHashMap.EntrySet
private class	FastCopyHashMap.FastCopyHashMapIterator<E>
private class	FastCopyHashMap.KeyIterator
private class	FastCopyHashMap.KeySet
protected static class	FastCopyHashMap.SimpleEntry<K,V>
private class	FastCopyHashMap.ValueIterator
private class	FastCopyHashMap.Values

Nested classes/interfaces inherited from class AbstractMap

AbstractMap.SimpleImmutableEntry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	DEFAULT_CAPACITY	Same default as HashMap, must be a power of 2
private static final float	DEFAULT_LOAD_FACTOR	67%, just like IdentityHashMap
private FastCopyHashMap<K,V>.EntrySet	entrySet
private FastCopyHashMap<K,V>.KeySet	keySet
private final float	loadFactor	The user defined load factor which defines when to resize
private static final int	MAXIMUM_CAPACITY	MAX_INT - 1
private int	modCount	Counter used to detect changes made outside of an iterator
private static final Object	NULL	Marks null keys.
private static final long	serialVersionUID	Serialization ID
private int	size	The current number of key-value pairs
private FastCopyHashMap.Entry<K,V>[]	table	The open-addressed table
private int	threshold	The next resize
private FastCopyHashMap<K,V>.Values	values

Constructor Summary

Constructors

Constructor	Description
FastCopyHashMap()
FastCopyHashMap(int initialCapacity)
FastCopyHashMap(int initialCapacity, float loadFactor)
FastCopyHashMap(Map<? extends K, ? extends V> map)

Method Summary

Modifier and Type	Method	Description
void	clear()
FastCopyHashMap<K,V>	clone()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()
private static final boolean	eq(Object o1, Object o2)
V	get(Object key)
private static final int	hash(Object key)
private static final int	index(int hashCode, int length)
private void	init(int initialCapacity, float loadFactor)
boolean	isEmpty()
Set<K>	keySet()
private static final <K> K	maskNull(K key)
private int	nextIndex(int index, int length)
void	printDebugStats()
V	put(K key, V value)
void	putAll(Map<? extends K, ? extends V> map)
private void	putForCreate(K key, V value)
private void	readObject(ObjectInputStream s)
private void	relocate(int start)
V	remove(Object key)
private void	resize(int from)
int	size()
private static final <K> K	unmaskNull(K key)
Collection<V>	values()
private void	writeObject(ObjectOutputStream s)

Methods inherited from class AbstractMap

equals, hashCode, toString

Methods inherited from class Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Map

compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Details

NULL

private static final Object NULL

Marks null keys.

serialVersionUID

private static final long serialVersionUID

Serialization ID

See Also:

• Constant Field Values

DEFAULT_CAPACITY

private static final int DEFAULT_CAPACITY

Same default as HashMap, must be a power of 2

See Also:

• Constant Field Values

MAXIMUM_CAPACITY

private static final int MAXIMUM_CAPACITY

MAX_INT - 1

See Also:

• Constant Field Values

DEFAULT_LOAD_FACTOR

private static final float DEFAULT_LOAD_FACTOR

67%, just like IdentityHashMap

See Also:

• Constant Field Values

table

private transient FastCopyHashMap.Entry<K,V>[] table

The open-addressed table

size

private transient int size

The current number of key-value pairs

threshold

private transient int threshold

The next resize

loadFactor

private final float loadFactor

The user defined load factor which defines when to resize

modCount

private transient int modCount

Counter used to detect changes made outside of an iterator

keySet

private transient FastCopyHashMap<K,V>.KeySet keySet

values

private transient FastCopyHashMap<K,V>.Values values

entrySet

private transient FastCopyHashMap<K,V>.EntrySet entrySet

Constructor Details

FastCopyHashMap

public FastCopyHashMap(int initialCapacity,
 float loadFactor)

FastCopyHashMap

public FastCopyHashMap(Map<? extends K, ? extends V> map)

FastCopyHashMap

public FastCopyHashMap(int initialCapacity)

FastCopyHashMap

public FastCopyHashMap()

Method Details

init

private void init(int initialCapacity,
 float loadFactor)

hash

private static final int hash(Object key)

maskNull

private static final <K> K maskNull(K key)

unmaskNull

private static final <K> K unmaskNull(K key)

nextIndex

private int nextIndex(int index,
 int length)

eq

private static final boolean eq(Object o1,
 Object o2)

index

private static final int index(int hashCode,
 int length)

size

public int size()

Specified by:

size in interface Map<K,V>

Overrides:

size in class AbstractMap<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

Overrides:

isEmpty in class AbstractMap<K,V>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class AbstractMap<K,V>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>

Overrides:

containsValue in class AbstractMap<K,V>

put

public V put(K key,
 V value)

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

resize

private void resize(int from)

putAll

public void putAll(Map<? extends K, ? extends V> map)

Specified by:

putAll in interface Map<K,V>

Overrides:

putAll in class AbstractMap<K,V>

remove

public V remove(Object key)

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>

relocate

private void relocate(int start)

clear

public void clear()

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>

clone

public FastCopyHashMap<K,V> clone()

Overrides:

clone in class AbstractMap<K,V>

printDebugStats

public void printDebugStats()

entrySet

public Set<Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class AbstractMap<K,V>

values

public Collection<V> values()

Specified by:

values in interface Map<K,V>

Overrides:

values in class AbstractMap<K,V>

readObject

private void readObject(ObjectInputStream s)
                 throws IOException,
ClassNotFoundException

Throws:

IOException

ClassNotFoundException

putForCreate

private void putForCreate(K key,
 V value)

writeObject

private void writeObject(ObjectOutputStream s)
                  throws IOException

Throws:

IOException