public class Object2ObjectOpenHashMap<K,V> extends AbstractObject2ObjectMap<K,V> implements Serializable, Cloneable, Hash
Instances of this class use a hash table to represent a map. The table is filled up to a specified load factor, and then doubled in size to accommodate new entries. If the table is emptied below one fourth of the load factor, it is halved in size. However, halving is not performed when deleting entries from an iterator, as it would interfere with the iteration process.
Note that clear() does not modify the hash table size. Rather, a family of trimming methods lets you control the size of the table; this is particularly useful if
you reuse instances of this class.
Hash,
HashCommon,
Serialized FormAbstractObject2ObjectMap.BasicEntry<K,V>Hash.Strategy<K>Object2ObjectMap.Entry<K,V>, Object2ObjectMap.FastEntrySet<K,V>DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR| Constructor and Description |
|---|
Object2ObjectOpenHashMap()
Creates a new hash map with initial expected
Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor. |
Object2ObjectOpenHashMap(int expected)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor. |
Object2ObjectOpenHashMap(int expected,
float f)
Creates a new hash map.
|
Object2ObjectOpenHashMap(K[] k,
V[] v)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays. |
Object2ObjectOpenHashMap(K[] k,
V[] v,
float f)
Creates a new hash map using the elements of two parallel arrays.
|
Object2ObjectOpenHashMap(Map<? extends K,? extends V> m)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one. |
Object2ObjectOpenHashMap(Map<? extends K,? extends V> m,
float f)
Creates a new hash map copying a given one.
|
Object2ObjectOpenHashMap(Object2ObjectMap<K,V> m)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one. |
Object2ObjectOpenHashMap(Object2ObjectMap<K,V> m,
float f)
Creates a new hash map copying a given type-specific one.
|
| Modifier and Type | Method and Description |
|---|---|
void |
clear()
Removes all associations from this function (optional operation).
|
Object2ObjectOpenHashMap<K,V> |
clone()
Returns a deep copy of this map.
|
boolean |
containsKey(Object k)
Checks whether the given value is contained in
AbstractObject2ObjectMap.keySet(). |
boolean |
containsValue(Object v)
Checks whether the given value is contained in
AbstractObject2ObjectMap.values(). |
V |
get(Object k)
Returns the value associated by this function to the specified key.
|
int |
growthFactor()
Deprecated.
Since
fastutil 6.1.0, hash tables are doubled when they are too full. |
void |
growthFactor(int growthFactor)
Deprecated.
Since
fastutil 6.1.0, hash tables are doubled when they are too full. |
int |
hashCode()
Returns a hash code for this map.
|
boolean |
isEmpty() |
ObjectSet<K> |
keySet()
Returns a type-specific-set view of the keys of this map.
|
Object2ObjectMap.FastEntrySet<K,V> |
object2ObjectEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
V |
put(K k,
V v)
Associates the specified value with the specified key in this function (optional operation).
|
void |
putAll(Map<? extends K,? extends V> m)
Puts all pairs in the given map.
|
boolean |
rehash()
Deprecated.
A no-op.
|
V |
remove(Object k)
Removes this key and the associated value from this function if it is present (optional operation).
|
int |
size()
Returns the intended number of keys in this function, or -1 if no such number exists.
|
boolean |
trim()
Rehashes the map, making the table as small as possible.
|
boolean |
trim(int n)
Rehashes this map if the table is too large.
|
ObjectCollection<V> |
values()
Returns a type-specific-set view of the values of this map.
|
entrySet, equals, toStringdefaultReturnValue, defaultReturnValuedefaultReturnValue, defaultReturnValuecompute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAllpublic Object2ObjectOpenHashMap(int expected,
float f)
The actual table size will be the least power of two greater than expected/f.
expected - the expected number of elements in the hash set.f - the load factor.public Object2ObjectOpenHashMap(int expected)
Hash.DEFAULT_LOAD_FACTOR as load factor.expected - the expected number of elements in the hash map.public Object2ObjectOpenHashMap()
Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.public Object2ObjectOpenHashMap(Map<? extends K,? extends V> m, float f)
m - a Map to be copied into the new hash map.f - the load factor.public Object2ObjectOpenHashMap(Map<? extends K,? extends V> m)
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.m - a Map to be copied into the new hash map.public Object2ObjectOpenHashMap(Object2ObjectMap<K,V> m, float f)
m - a type-specific map to be copied into the new hash map.f - the load factor.public Object2ObjectOpenHashMap(Object2ObjectMap<K,V> m)
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.m - a type-specific map to be copied into the new hash map.public Object2ObjectOpenHashMap(K[] k, V[] v, float f)
k - the array of keys of the new hash map.v - the array of corresponding values in the new hash map.f - the load factor.IllegalArgumentException - if k and v have different lengths.public Object2ObjectOpenHashMap(K[] k, V[] v)
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.k - the array of keys of the new hash map.v - the array of corresponding values in the new hash map.IllegalArgumentException - if k and v have different lengths.public void putAll(Map<? extends K,? extends V> m)
public V put(K k, V v)
Functionpublic V remove(Object k)
Functionpublic V get(Object k)
Functionpublic boolean containsKey(Object k)
AbstractObject2ObjectMapAbstractObject2ObjectMap.keySet().containsKey in interface Function<K,V>containsKey in interface Map<K,V>containsKey in class AbstractObject2ObjectMap<K,V>k - the key.key.Map.containsKey(Object)public boolean containsValue(Object v)
AbstractObject2ObjectMapAbstractObject2ObjectMap.values().containsValue in interface Map<K,V>containsValue in class AbstractObject2ObjectMap<K,V>public void clear()
Functionpublic int size()
FunctionMost function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible.
public boolean isEmpty()
@Deprecated public void growthFactor(int growthFactor)
fastutil 6.1.0, hash tables are doubled when they are too full.growthFactor - unused.@Deprecated public int growthFactor()
fastutil 6.1.0, hash tables are doubled when they are too full.growthFactor(int)public Object2ObjectMap.FastEntrySet<K,V> object2ObjectEntrySet()
Object2ObjectMapThis method is necessary because there is no inheritance along type parameters: it is thus impossible to strengthen Object2ObjectMap.entrySet() so that it returns an
ObjectSet of type-specific entries (the latter makes it possible to access keys and values with type-specific methods).
object2ObjectEntrySet in interface Object2ObjectMap<K,V>Object2ObjectMap.entrySet()public ObjectSet<K> keySet()
AbstractObject2ObjectMapThe view is backed by the set returned by AbstractObject2ObjectMap.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that
lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient
ad-hoc implementations.
keySet in interface Object2ObjectMap<K,V>keySet in interface Map<K,V>keySet in class AbstractObject2ObjectMap<K,V>Map.keySet()public ObjectCollection<V> values()
AbstractObject2ObjectMapThe view is backed by the set returned by AbstractObject2ObjectMap.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that
lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient
ad-hoc implementations.
values in interface Object2ObjectMap<K,V>values in interface Map<K,V>values in class AbstractObject2ObjectMap<K,V>Map.values()@Deprecated public boolean rehash()
If you need to reduce the table size to fit exactly this set, use trim().
trim()public boolean trim()
This method rehashes the table to the smallest size satisfying the load factor. It can be used when the set will not be changed anymore, so to optimize access speed and size.
If the table size is already the minimum possible, this method does nothing.
trim(int)public boolean trim(int n)
Let N be the smallest table size that can hold max(n, entries, still satisfying the load factor. If the current table size is smaller than or equal to
N, this method does nothing. Otherwise, it rehashes this map in a table of size N.
size())
This method is useful when reusing maps. Clearing a map leaves the table size untouched. If you are reusing a map many times, you can call this method with a typical size to avoid keeping around a very large table just because of a few large transient maps.
n - the threshold for the trimming.trim()public Object2ObjectOpenHashMap<K,V> clone()
This method performs a deep copy of this hash map; the data stored in the map, however, is not cloned. Note that this makes a difference only for object keys.
public int hashCode()
equals() is not overriden, it is important that the value returned by this method is the same value as
the one returned by the overriden method.