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java.lang.Objectit.unimi.dsi.fastutil.bytes.AbstractByte2ObjectFunction<V>
it.unimi.dsi.fastutil.bytes.AbstractByte2ObjectMap<V>
it.unimi.dsi.fastutil.bytes.Byte2ObjectOpenCustomHashMap<V>
public class Byte2ObjectOpenCustomHashMap<V>
A type-specific hash map with a fast, small-footprint implementation whose hashing strategy is specified at creation time.
Instances of this class use a hash table to represent a map. The table is
enlarged as needed by doubling its size when new entries are created, but it is never made
smaller (even on a clear()
). A family of trimming
methods lets you control the size of the table; this is particularly useful
if you reuse instances of this class.
Warning: The implementation of this class has significantly
changed in fastutil
6.1.0. Please read the
comments about this issue in the section “Faster Hash Tables” of the overview.
Hash
,
HashCommon
,
Serialized FormNested Class Summary |
---|
Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.bytes.AbstractByte2ObjectMap |
---|
AbstractByte2ObjectMap.BasicEntry<V> |
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash |
---|
Hash.Strategy<K> |
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.bytes.Byte2ObjectMap |
---|
Byte2ObjectMap.Entry<V>, Byte2ObjectMap.FastEntrySet<V> |
Field Summary |
---|
Fields inherited from interface it.unimi.dsi.fastutil.Hash |
---|
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR |
Constructor Summary | |
---|---|
Byte2ObjectOpenCustomHashMap(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. |
|
Byte2ObjectOpenCustomHashMap(byte[] k,
V[] v,
float f,
ByteHash.Strategy strategy)
Creates a new hash map using the elements of two parallel arrays. |
|
Byte2ObjectOpenCustomHashMap(Byte2ObjectMap<V> m,
ByteHash.Strategy strategy)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one. |
|
Byte2ObjectOpenCustomHashMap(Byte2ObjectMap<V> m,
float f,
ByteHash.Strategy strategy)
Creates a new hash map copying a given type-specific one. |
|
Byte2ObjectOpenCustomHashMap(ByteHash.Strategy strategy)
Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
|
Byte2ObjectOpenCustomHashMap(int expected,
ByteHash.Strategy strategy)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor. |
|
Byte2ObjectOpenCustomHashMap(int expected,
float f,
ByteHash.Strategy strategy)
Creates a new hash map. |
|
Byte2ObjectOpenCustomHashMap(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. |
|
Byte2ObjectOpenCustomHashMap(java.util.Map<? extends java.lang.Byte,? extends V> m,
float f,
ByteHash.Strategy strategy)
Creates a new hash map copying a given one. |
Method Summary | |
---|---|
Byte2ObjectMap.FastEntrySet<V> |
byte2ObjectEntrySet()
Returns a type-specific set view of the mappings contained in this map. |
void |
clear()
Removes all associations from this function (optional operation). |
Byte2ObjectOpenCustomHashMap<V> |
clone()
Returns a deep copy of this map. |
boolean |
containsKey(byte k)
Checks whether the given value is contained in AbstractByte2ObjectMap.keySet() . |
boolean |
containsValue(java.lang.Object v)
Checks whether the given value is contained in AbstractByte2ObjectMap.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. |
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. |
ObjectCollection<V> |
values()
Returns a type-specific-set view of the values of this map. |
Methods inherited from class it.unimi.dsi.fastutil.bytes.AbstractByte2ObjectMap |
---|
entrySet, equals, putAll, toString |
Methods inherited from class it.unimi.dsi.fastutil.bytes.AbstractByte2ObjectFunction |
---|
containsKey, defaultReturnValue, defaultReturnValue, get |
Methods inherited from class java.lang.Object |
---|
getClass, notify, notifyAll, wait, wait, wait |
Methods inherited from interface it.unimi.dsi.fastutil.bytes.Byte2ObjectFunction |
---|
defaultReturnValue, defaultReturnValue |
Methods inherited from interface it.unimi.dsi.fastutil.Function |
---|
containsKey, get |
Methods inherited from interface java.util.Map |
---|
containsKey, get |
Constructor Detail |
---|
public Byte2ObjectOpenCustomHashMap(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 Byte2ObjectOpenCustomHashMap(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 Byte2ObjectOpenCustomHashMap(ByteHash.Strategy strategy)
Hash.DEFAULT_INITIAL_SIZE
entries
and Hash.DEFAULT_LOAD_FACTOR
as load factor.
strategy
- the strategy.public Byte2ObjectOpenCustomHashMap(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 Byte2ObjectOpenCustomHashMap(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 Byte2ObjectOpenCustomHashMap(Byte2ObjectMap<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 Byte2ObjectOpenCustomHashMap(Byte2ObjectMap<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 Byte2ObjectOpenCustomHashMap(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 Byte2ObjectOpenCustomHashMap(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.Method Detail |
---|
public ByteHash.Strategy strategy()
public V put(byte k, V v)
Byte2ObjectFunction
put
in interface Byte2ObjectFunction<V>
put
in class AbstractByte2ObjectFunction<V>
k
- the key.v
- the value.
Function.put(Object,Object)
public V put(java.lang.Byte ok, V ov)
AbstractByte2ObjectFunction
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 AbstractByte2ObjectFunction<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)
Byte2ObjectFunction
remove
in interface Byte2ObjectFunction<V>
remove
in class AbstractByte2ObjectFunction<V>
Function.remove(Object)
public V remove(java.lang.Object ok)
AbstractByte2ObjectFunction
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 AbstractByte2ObjectFunction<V>
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)
Byte2ObjectFunction
get
in interface Byte2ObjectFunction<V>
k
- the key.
Function.get(Object)
public boolean containsKey(byte k)
AbstractByte2ObjectMap
AbstractByte2ObjectMap.keySet()
.
containsKey
in interface Byte2ObjectFunction<V>
containsKey
in class AbstractByte2ObjectMap<V>
Function.containsKey(Object)
public boolean containsValue(java.lang.Object v)
AbstractByte2ObjectMap
AbstractByte2ObjectMap.values()
.
containsValue
in interface java.util.Map<java.lang.Byte,V>
containsValue
in class AbstractByte2ObjectMap<V>
public void clear()
Function
clear
in interface Function<java.lang.Byte,V>
clear
in interface java.util.Map<java.lang.Byte,V>
clear
in class AbstractByte2ObjectFunction<V>
Map.clear()
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.
size
in interface Function<java.lang.Byte,V>
size
in interface java.util.Map<java.lang.Byte,V>
public boolean isEmpty()
isEmpty
in interface java.util.Map<java.lang.Byte,V>
isEmpty
in class AbstractByte2ObjectMap<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 Byte2ObjectMap.FastEntrySet<V> byte2ObjectEntrySet()
Byte2ObjectMap
This method is necessary because there is no inheritance along
type parameters: it is thus impossible to strengthen Byte2ObjectMap.entrySet()
so that it returns an ObjectSet
of objects of type Map.Entry
(the latter makes it possible to
access keys and values with type-specific methods).
byte2ObjectEntrySet
in interface Byte2ObjectMap<V>
Byte2ObjectMap.entrySet()
public ByteSet keySet()
AbstractByte2ObjectMap
The view is backed by the set returned by AbstractByte2ObjectMap.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 Byte2ObjectMap<V>
keySet
in interface java.util.Map<java.lang.Byte,V>
keySet
in class AbstractByte2ObjectMap<V>
Map.keySet()
public ObjectCollection<V> values()
AbstractByte2ObjectMap
The view is backed by the set returned by AbstractByte2ObjectMap.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 Byte2ObjectMap<V>
values
in interface java.util.Map<java.lang.Byte,V>
values
in class AbstractByte2ObjectMap<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 Byte2ObjectOpenCustomHashMap<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 AbstractByte2ObjectMap<V>
|
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