public class Byte2ReferenceOpenCustomHashMap<V> extends AbstractByte2ReferenceMap<V> implements java.io.Serializable, java.lang.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 FormAbstractByte2ReferenceMap.BasicEntry<V>
Hash.Strategy<K>
Byte2ReferenceMap.Entry<V>, Byte2ReferenceMap.FastEntrySet<V>
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR
Constructor and Description |
---|
Byte2ReferenceOpenCustomHashMap(byte[] k,
V[] v,
ByteHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays. |
Byte2ReferenceOpenCustomHashMap(byte[] k,
V[] v,
float f,
ByteHash.Strategy strategy)
Creates a new hash map using the elements of two parallel arrays.
|
Byte2ReferenceOpenCustomHashMap(Byte2ReferenceMap<V> m,
ByteHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one. |
Byte2ReferenceOpenCustomHashMap(Byte2ReferenceMap<V> m,
float f,
ByteHash.Strategy strategy)
Creates a new hash map copying a given type-specific one.
|
Byte2ReferenceOpenCustomHashMap(ByteHash.Strategy strategy)
Creates a new hash map with initial expected
Hash.DEFAULT_INITIAL_SIZE entries
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
Byte2ReferenceOpenCustomHashMap(int expected,
ByteHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor. |
Byte2ReferenceOpenCustomHashMap(int expected,
float f,
ByteHash.Strategy strategy)
Creates a new hash map.
|
Byte2ReferenceOpenCustomHashMap(java.util.Map<? extends java.lang.Byte,? extends V> m,
ByteHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one. |
Byte2ReferenceOpenCustomHashMap(java.util.Map<? extends java.lang.Byte,? extends V> m,
float f,
ByteHash.Strategy strategy)
Creates a new hash map copying a given one.
|
Modifier and Type | Method and Description |
---|---|
Byte2ReferenceMap.FastEntrySet<V> |
byte2ReferenceEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
void |
clear()
Removes all associations from this function (optional operation).
|
Byte2ReferenceOpenCustomHashMap<V> |
clone()
Returns a deep copy of this map.
|
boolean |
containsKey(byte k)
Checks whether the given value is contained in
AbstractByte2ReferenceMap.keySet() . |
boolean |
containsValue(java.lang.Object v)
Checks whether the given value is contained in
AbstractByte2ReferenceMap.values() . |
V |
get(byte k)
Returns the value to which the given key is mapped.
|
V |
get(java.lang.Byte ok) |
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() |
ByteSet |
keySet()
Returns a type-specific-set view of the keys of this map.
|
V |
put(byte k,
V v)
Adds a pair to the map.
|
V |
put(java.lang.Byte ok,
V ov)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
void |
putAll(java.util.Map<? extends java.lang.Byte,? extends V> m)
Puts all pairs in the given map.
|
boolean |
rehash()
Deprecated.
A no-op.
|
V |
remove(byte k)
Removes the mapping with the given key.
|
V |
remove(java.lang.Object ok)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
int |
size()
Returns the intended number of keys in this function, or -1 if no such number exists.
|
ByteHash.Strategy |
strategy()
Returns the hashing strategy.
|
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.
|
ReferenceCollection<V> |
values()
Returns a type-specific-set view of the values of this map.
|
entrySet, equals, toString
containsKey, defaultReturnValue, defaultReturnValue, get
defaultReturnValue, defaultReturnValue
containsKey, get
public Byte2ReferenceOpenCustomHashMap(int expected, float f, ByteHash.Strategy strategy)
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.strategy
- the strategy.public Byte2ReferenceOpenCustomHashMap(int expected, ByteHash.Strategy strategy)
Hash.DEFAULT_LOAD_FACTOR
as load factor.expected
- the expected number of elements in the hash map.strategy
- the strategy.public Byte2ReferenceOpenCustomHashMap(ByteHash.Strategy strategy)
Hash.DEFAULT_INITIAL_SIZE
entries
and Hash.DEFAULT_LOAD_FACTOR
as load factor.strategy
- the strategy.public Byte2ReferenceOpenCustomHashMap(java.util.Map<? extends java.lang.Byte,? extends V> m, float f, ByteHash.Strategy strategy)
m
- a Map
to be copied into the new hash map.f
- the load factor.strategy
- the strategy.public Byte2ReferenceOpenCustomHashMap(java.util.Map<? extends java.lang.Byte,? extends V> m, ByteHash.Strategy strategy)
Hash.DEFAULT_LOAD_FACTOR
as load factor copying a given one.m
- a Map
to be copied into the new hash map.strategy
- the strategy.public Byte2ReferenceOpenCustomHashMap(Byte2ReferenceMap<V> m, float f, ByteHash.Strategy strategy)
m
- a type-specific map to be copied into the new hash map.f
- the load factor.strategy
- the strategy.public Byte2ReferenceOpenCustomHashMap(Byte2ReferenceMap<V> m, ByteHash.Strategy strategy)
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.strategy
- the strategy.public Byte2ReferenceOpenCustomHashMap(byte[] k, V[] v, float f, ByteHash.Strategy strategy)
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.strategy
- the strategy.java.lang.IllegalArgumentException
- if k
and v
have different lengths.public Byte2ReferenceOpenCustomHashMap(byte[] k, V[] v, ByteHash.Strategy strategy)
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.strategy
- the strategy.java.lang.IllegalArgumentException
- if k
and v
have different lengths.public ByteHash.Strategy strategy()
public void putAll(java.util.Map<? extends java.lang.Byte,? extends V> m)
putAll
in interface java.util.Map<java.lang.Byte,V>
putAll
in class AbstractByte2ReferenceMap<V>
m
- a map.public V put(byte k, V v)
Byte2ReferenceFunction
put
in interface Byte2ReferenceFunction<V>
put
in class AbstractByte2ReferenceFunction<V>
k
- the key.v
- the value.Function.put(Object,Object)
public V put(java.lang.Byte ok, V ov)
AbstractByte2ReferenceFunction
null
on a missing key.
This method must check whether the provided key is in the map using containsKey()
. Thus,
it probes the map twice. Implementors of subclasses should override it with a more efficient method.
put
in interface Function<java.lang.Byte,V>
put
in interface java.util.Map<java.lang.Byte,V>
put
in class AbstractByte2ReferenceFunction<V>
ok
- the key.ov
- the value.null
if no value was present for the given key.Map.put(Object,Object)
public V remove(byte k)
Byte2ReferenceFunction
remove
in interface Byte2ReferenceFunction<V>
remove
in class AbstractByte2ReferenceFunction<V>
k
- the key.Function.remove(Object)
public V remove(java.lang.Object ok)
AbstractByte2ReferenceFunction
null
on a missing key.
This method must check whether the provided key is in the map using containsKey()
. Thus,
it probes the map twice. Implementors of subclasses should override it with a more efficient method.
remove
in interface Function<java.lang.Byte,V>
remove
in interface java.util.Map<java.lang.Byte,V>
remove
in class AbstractByte2ReferenceFunction<V>
ok
- the key.null
if no value was present for the given key.Map.remove(Object)
public V get(java.lang.Byte ok)
public V get(byte k)
Byte2ReferenceFunction
get
in interface Byte2ReferenceFunction<V>
k
- the key.Function.get(Object)
public boolean containsKey(byte k)
AbstractByte2ReferenceMap
AbstractByte2ReferenceMap.keySet()
.containsKey
in interface Byte2ReferenceFunction<V>
containsKey
in class AbstractByte2ReferenceMap<V>
Function.containsKey(Object)
public boolean containsValue(java.lang.Object v)
AbstractByte2ReferenceMap
AbstractByte2ReferenceMap.values()
.containsValue
in interface java.util.Map<java.lang.Byte,V>
containsValue
in class AbstractByte2ReferenceMap<V>
public void clear()
Function
public int size()
Function
Most 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()
isEmpty
in interface java.util.Map<java.lang.Byte,V>
isEmpty
in class AbstractByte2ReferenceMap<V>
@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 Byte2ReferenceMap.FastEntrySet<V> byte2ReferenceEntrySet()
Byte2ReferenceMap
This method is necessary because there is no inheritance along
type parameters: it is thus impossible to strengthen Byte2ReferenceMap.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).
byte2ReferenceEntrySet
in interface Byte2ReferenceMap<V>
Byte2ReferenceMap.entrySet()
public ByteSet keySet()
AbstractByte2ReferenceMap
The view is backed by the set returned by AbstractByte2ReferenceMap.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 Byte2ReferenceMap<V>
keySet
in interface java.util.Map<java.lang.Byte,V>
keySet
in class AbstractByte2ReferenceMap<V>
Map.keySet()
public ReferenceCollection<V> values()
AbstractByte2ReferenceMap
The view is backed by the set returned by AbstractByte2ReferenceMap.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 Byte2ReferenceMap<V>
values
in interface java.util.Map<java.lang.Byte,V>
values
in class AbstractByte2ReferenceMap<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 Byte2ReferenceOpenCustomHashMap<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.
clone
in class java.lang.Object
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.hashCode
in interface java.util.Map<java.lang.Byte,V>
hashCode
in class AbstractByte2ReferenceMap<V>