Package gnu.kawa.util

Class AbstractHashTable<Entry extends Map.Entry<K,V>,K,V>

java.lang.Object

java.util.AbstractMap<K,V>

gnu.kawa.util.AbstractHashTable<Entry,K,V>

All Implemented Interfaces:

Map<K,V>

Direct Known Subclasses:

AbstractWeakHashTable, GeneralHashTable, Namespace, WeakIdentityHashMap

public abstract class AbstractHashTable<Entry extends Map.Entry<K,V>,K,V>
extends AbstractMap<K,V>

An abstract hash map from K to V. The entries are represented by an Entry type parameter.

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_INITIAL_SIZE
protected int	mask
protected int	num_bindings
protected Entry[]	table

Constructor Summary

Constructors

Constructor	Description
AbstractHashTable()
AbstractHashTable(int capacity)

Method Summary

Modifier and Type	Method	Description
protected abstract Entry[]	allocEntries(int n)	Allocate Entry[n].
void	clear()
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)	Find value for given key.
V	get(Object key, V defaultValue)	Find value for given key.
protected abstract int	getEntryHashCode(Entry entry)	Extract hash-code from Entry.
protected abstract Entry	getEntryNext(Entry entry)	Extract next Entry in same hash-bucket.
Entry	getNode(Object key)	Find Entry for given key.
V	getOrDefault(Object key, V defaultValue)
int	hash(Object key)	Calculate hash code of a key.
protected int	hashToIndex(int hash)	Map hash-code to bucket index in table.
protected abstract Entry	makeEntry(K key, int hash, V value)	Allocate a new node in the hash table.
protected boolean	matches(Object key, int hash, Entry node)	True if an Entry matches a key.
protected boolean	matches(K key1, Object key2)	Compare two keys for equivalence.
V	put(K key, int hash, V value)
V	put(K key, V value)
protected void	rehash()
V	remove(Object key)
protected abstract void	setEntryNext(Entry entry, Entry next)	Set next Entry in same hash-bucket.
int	size()

Methods inherited from class java.util.AbstractMap

clone, containsKey, containsValue, equals, hashCode, isEmpty, keySet, putAll, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Details

table

protected Entry extends Map.Entry<K,V>[] table

mask

protected int mask

num_bindings

protected int num_bindings

DEFAULT_INITIAL_SIZE

public static final int DEFAULT_INITIAL_SIZE

See Also:

• Constant Field Values

Constructor Details

AbstractHashTable

public AbstractHashTable()

AbstractHashTable

public AbstractHashTable(int capacity)

Method Details

getEntryHashCode

protected abstract int getEntryHashCode(Entry entry)

Extract hash-code from Entry.

getEntryNext

protected abstract Entry getEntryNext(Entry entry)

Extract next Entry in same hash-bucket.

setEntryNext

protected abstract void setEntryNext(Entry entry,
 Entry next)

Set next Entry in same hash-bucket.

allocEntries

protected abstract Entry[] allocEntries(int n)

Allocate Entry[n].

makeEntry

protected abstract Entry makeEntry(K key,
 int hash,
 V value)

Allocate a new node in the hash table.

hash

public int hash(Object key)

Calculate hash code of a key.

hashToIndex

protected int hashToIndex(int hash)

Map hash-code to bucket index in table.

matches

protected boolean matches(Object key,
 int hash,
 Entry node)

True if an Entry matches a key.

matches

protected boolean matches(K key1,
 Object key2)

Compare two keys for equivalence. Override this and the hash(Object) method if you want a different equivalence relation.

get

public V get(Object key)

Find value for given key. Return null if not found.

Specified by:

get in interface Map<Entry extends Map.Entry<K,V>,K>

Overrides:

get in class AbstractMap<K,V>

getNode

public Entry getNode(Object key)

Find Entry for given key. Return null if not found.

get

public V get(Object key,
 V defaultValue)

Find value for given key. Return defaultValue if not found.

getOrDefault

public V getOrDefault(Object key,
 V defaultValue)

rehash

protected void rehash()

put

public V put(K key,
 V value)

Specified by:

put in interface Map<Entry extends Map.Entry<K,V>,K>

Overrides:

put in class AbstractMap<K,V>

put

public V put(K key,
 int hash,
 V value)

remove

public V remove(Object key)

Specified by:

remove in interface Map<Entry extends Map.Entry<K,V>,K>

Overrides:

remove in class AbstractMap<K,V>

clear

public void clear()

Specified by:

clear in interface Map<Entry extends Map.Entry<K,V>,K>

Overrides:

clear in class AbstractMap<K,V>

size

public int size()

Specified by:

size in interface Map<Entry extends Map.Entry<K,V>,K>

Overrides:

size in class AbstractMap<K,V>

entrySet

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

Specified by:

entrySet in interface Map<Entry extends Map.Entry<K,V>,K>

Specified by:

entrySet in class AbstractMap<K,V>