public class Int2IntOpenCustomHashMap extends AbstractInt2IntMap implements Serializable, Cloneable, Hash
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 FormAbstractInt2IntMap.BasicEntry
Hash.Strategy<K>
Int2IntMap.Entry, Int2IntMap.FastEntrySet
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR
Constructor and Description |
---|
Int2IntOpenCustomHashMap(int[] k,
int[] v,
float f,
IntHash.Strategy strategy)
Creates a new hash map using the elements of two parallel arrays.
|
Int2IntOpenCustomHashMap(int[] k,
int[] v,
IntHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays. |
Int2IntOpenCustomHashMap(Int2IntMap m,
float f,
IntHash.Strategy strategy)
Creates a new hash map copying a given type-specific one.
|
Int2IntOpenCustomHashMap(Int2IntMap m,
IntHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one. |
Int2IntOpenCustomHashMap(int expected,
float f,
IntHash.Strategy strategy)
Creates a new hash map.
|
Int2IntOpenCustomHashMap(IntHash.Strategy strategy)
Creates a new hash map with initial expected
Hash.DEFAULT_INITIAL_SIZE entries
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
Int2IntOpenCustomHashMap(int expected,
IntHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor. |
Int2IntOpenCustomHashMap(Map<? extends Integer,? extends Integer> m,
float f,
IntHash.Strategy strategy)
Creates a new hash map copying a given one.
|
Int2IntOpenCustomHashMap(Map<? extends Integer,? extends Integer> m,
IntHash.Strategy strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one. |
Modifier and Type | Method and Description |
---|---|
int |
add(int k,
int incr)
Deprecated.
use
addTo() instead; having the same name of a Set method turned out to be a recipe for disaster. |
int |
addTo(int k,
int incr)
Adds an increment to value currently associated with a key.
|
void |
clear()
Removes all associations from this function (optional operation).
|
Int2IntOpenCustomHashMap |
clone()
Returns a deep copy of this map.
|
boolean |
containsKey(int k)
Checks whether the given value is contained in
AbstractInt2IntMap.keySet() . |
boolean |
containsValue(int v)
Checks whether the given value is contained in
AbstractInt2IntMap.values() . |
int |
get(int k)
Returns the value to which the given key is mapped.
|
Integer |
get(Integer 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.
|
Int2IntMap.FastEntrySet |
int2IntEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
boolean |
isEmpty() |
IntSet |
keySet()
Returns a type-specific-set view of the keys of this map.
|
Integer |
put(Integer ok,
Integer ov)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
int |
put(int k,
int v)
Adds a pair to the map.
|
boolean |
rehash()
Deprecated.
A no-op.
|
int |
remove(int k)
Removes the mapping with the given key.
|
Integer |
remove(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.
|
IntHash.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.
|
IntCollection |
values()
Returns a type-specific-set view of the values of this map.
|
containsValue, entrySet, equals, putAll, toString
containsKey, defaultReturnValue, defaultReturnValue, get
defaultReturnValue, defaultReturnValue
containsKey, get
containsKey, get
public Int2IntOpenCustomHashMap(int expected, float f, IntHash.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 Int2IntOpenCustomHashMap(int expected, IntHash.Strategy strategy)
Hash.DEFAULT_LOAD_FACTOR
as load factor.expected
- the expected number of elements in the hash map.strategy
- the strategy.public Int2IntOpenCustomHashMap(IntHash.Strategy strategy)
Hash.DEFAULT_INITIAL_SIZE
entries
and Hash.DEFAULT_LOAD_FACTOR
as load factor.strategy
- the strategy.public Int2IntOpenCustomHashMap(Map<? extends Integer,? extends Integer> m, float f, IntHash.Strategy strategy)
m
- a Map
to be copied into the new hash map.f
- the load factor.strategy
- the strategy.public Int2IntOpenCustomHashMap(Map<? extends Integer,? extends Integer> m, IntHash.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 Int2IntOpenCustomHashMap(Int2IntMap m, float f, IntHash.Strategy strategy)
m
- a type-specific map to be copied into the new hash map.f
- the load factor.strategy
- the strategy.public Int2IntOpenCustomHashMap(Int2IntMap m, IntHash.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 Int2IntOpenCustomHashMap(int[] k, int[] v, float f, IntHash.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.IllegalArgumentException
- if k
and v
have different lengths.public Int2IntOpenCustomHashMap(int[] k, int[] v, IntHash.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.IllegalArgumentException
- if k
and v
have different lengths.public IntHash.Strategy strategy()
public int put(int k, int v)
Int2IntFunction
put
in interface Int2IntFunction
put
in class AbstractInt2IntFunction
k
- the key.v
- the value.Function.put(Object,Object)
public Integer put(Integer ok, Integer ov)
AbstractInt2IntFunction
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<Integer,Integer>
put
in interface Map<Integer,Integer>
put
in class AbstractInt2IntFunction
ok
- the key.ov
- the value.null
if no value was present for the given key.Map.put(Object,Object)
@Deprecated public int add(int k, int incr)
addTo()
instead; having the same name of a Set
method turned out to be a recipe for disaster.k
- the key.incr
- the increment.public int addTo(int k, int incr)
Note that this method respects the default return value semantics: when called with a key that does not currently appears in the map, the key will be associated with the default return value plus the given increment.
k
- the key.incr
- the increment.public int remove(int k)
Int2IntFunction
remove
in interface Int2IntFunction
remove
in class AbstractInt2IntFunction
Function.remove(Object)
public Integer remove(Object ok)
AbstractInt2IntFunction
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.
public int get(int k)
Int2IntFunction
get
in interface Int2IntFunction
k
- the key.Function.get(Object)
public boolean containsKey(int k)
AbstractInt2IntMap
AbstractInt2IntMap.keySet()
.containsKey
in interface Int2IntFunction
containsKey
in class AbstractInt2IntMap
Function.containsKey(Object)
public boolean containsValue(int v)
AbstractInt2IntMap
AbstractInt2IntMap.values()
.containsValue
in interface Int2IntMap
containsValue
in class AbstractInt2IntMap
Map.containsValue(Object)
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()
@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 Int2IntMap.FastEntrySet int2IntEntrySet()
Int2IntMap
This method is necessary because there is no inheritance along
type parameters: it is thus impossible to strengthen Int2IntMap.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).
int2IntEntrySet
in interface Int2IntMap
Int2IntMap.entrySet()
public IntSet keySet()
AbstractInt2IntMap
The view is backed by the set returned by AbstractInt2IntMap.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 Int2IntMap
keySet
in interface Map<Integer,Integer>
keySet
in class AbstractInt2IntMap
Map.keySet()
public IntCollection values()
AbstractInt2IntMap
The view is backed by the set returned by AbstractInt2IntMap.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 Int2IntMap
values
in interface Map<Integer,Integer>
values
in class AbstractInt2IntMap
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 Int2IntOpenCustomHashMap 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.