public class Reference2LongOpenHashMap<K> extends AbstractReference2LongMap<K> 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 FormAbstractReference2LongMap.BasicEntry<K>
Hash.Strategy<K>
Reference2LongMap.Entry<K>, Reference2LongMap.FastEntrySet<K>
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR
Constructor and Description |
---|
Reference2LongOpenHashMap()
Creates a new hash map with initial expected
Hash.DEFAULT_INITIAL_SIZE entries
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
Reference2LongOpenHashMap(int expected)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor. |
Reference2LongOpenHashMap(int expected,
float f)
Creates a new hash map.
|
Reference2LongOpenHashMap(K[] k,
long[] v)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays. |
Reference2LongOpenHashMap(K[] k,
long[] v,
float f)
Creates a new hash map using the elements of two parallel arrays.
|
Reference2LongOpenHashMap(Map<? extends K,? extends Long> m)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one. |
Reference2LongOpenHashMap(Map<? extends K,? extends Long> m,
float f)
Creates a new hash map copying a given one.
|
Reference2LongOpenHashMap(Reference2LongMap<K> m)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one. |
Reference2LongOpenHashMap(Reference2LongMap<K> m,
float f)
Creates a new hash map copying a given type-specific one.
|
Modifier and Type | Method and Description |
---|---|
long |
add(K k,
long incr)
Deprecated.
use
addTo() instead; having the same name of a Set method turned out to be a recipe for disaster. |
long |
addTo(K k,
long incr)
Adds an increment to value currently associated with a key.
|
void |
clear()
Removes all associations from this function (optional operation).
|
Reference2LongOpenHashMap<K> |
clone()
Returns a deep copy of this map.
|
boolean |
containsKey(Object k)
Checks whether the given value is contained in
AbstractReference2LongMap.keySet() . |
boolean |
containsValue(long v)
Checks whether the given value is contained in
AbstractReference2LongMap.values() . |
long |
getLong(Object k)
Returns the value to which the given key is mapped.
|
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() |
ReferenceSet<K> |
keySet()
Returns a type-specific-set view of the keys of this map.
|
long |
put(K k,
long v)
Adds a pair to the map.
|
Long |
put(K ok,
Long ov)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
Reference2LongMap.FastEntrySet<K> |
reference2LongEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
boolean |
rehash()
Deprecated.
A no-op.
|
Long |
remove(Object ok)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
long |
removeLong(Object k)
Removes the mapping with the given key.
|
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.
|
LongCollection |
values()
Returns a type-specific-set view of the values of this map.
|
containsValue, entrySet, equals, putAll, toString
defaultReturnValue, defaultReturnValue, get
defaultReturnValue, defaultReturnValue
public Reference2LongOpenHashMap(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 Reference2LongOpenHashMap(int expected)
Hash.DEFAULT_LOAD_FACTOR
as load factor.expected
- the expected number of elements in the hash map.public Reference2LongOpenHashMap()
Hash.DEFAULT_INITIAL_SIZE
entries
and Hash.DEFAULT_LOAD_FACTOR
as load factor.public Reference2LongOpenHashMap(Map<? extends K,? extends Long> m, float f)
m
- a Map
to be copied into the new hash map.f
- the load factor.public Reference2LongOpenHashMap(Map<? extends K,? extends Long> m)
Hash.DEFAULT_LOAD_FACTOR
as load factor copying a given one.m
- a Map
to be copied into the new hash map.public Reference2LongOpenHashMap(Reference2LongMap<K> m, float f)
m
- a type-specific map to be copied into the new hash map.f
- the load factor.public Reference2LongOpenHashMap(Reference2LongMap<K> 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 Reference2LongOpenHashMap(K[] k, long[] 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 Reference2LongOpenHashMap(K[] k, long[] 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 long put(K k, long v)
Reference2LongFunction
put
in interface Reference2LongFunction<K>
put
in class AbstractReference2LongFunction<K>
k
- the key.v
- the value.Function.put(Object,Object)
public Long put(K ok, Long ov)
AbstractReference2LongFunction
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.
@Deprecated public long add(K k, long 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 long addTo(K k, long 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 long removeLong(Object k)
Reference2LongFunction
removeLong
in interface Reference2LongFunction<K>
removeLong
in class AbstractReference2LongFunction<K>
Function.remove(Object)
public Long remove(Object ok)
AbstractReference2LongFunction
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 long getLong(Object k)
Reference2LongFunction
getLong
in interface Reference2LongFunction<K>
k
- the key.Function.get(Object)
public boolean containsKey(Object k)
AbstractReference2LongMap
AbstractReference2LongMap.keySet()
.containsKey
in interface Function<K,Long>
containsKey
in interface Map<K,Long>
containsKey
in class AbstractReference2LongMap<K>
k
- the key.key
.Map.containsKey(Object)
public boolean containsValue(long v)
AbstractReference2LongMap
AbstractReference2LongMap.values()
.containsValue
in interface Reference2LongMap<K>
containsValue
in class AbstractReference2LongMap<K>
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 Reference2LongMap.FastEntrySet<K> reference2LongEntrySet()
Reference2LongMap
This method is necessary because there is no inheritance along
type parameters: it is thus impossible to strengthen Reference2LongMap.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).
reference2LongEntrySet
in interface Reference2LongMap<K>
Reference2LongMap.entrySet()
public ReferenceSet<K> keySet()
AbstractReference2LongMap
The view is backed by the set returned by AbstractReference2LongMap.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 Reference2LongMap<K>
keySet
in interface Map<K,Long>
keySet
in class AbstractReference2LongMap<K>
Map.keySet()
public LongCollection values()
AbstractReference2LongMap
The view is backed by the set returned by AbstractReference2LongMap.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 Reference2LongMap<K>
values
in interface Map<K,Long>
values
in class AbstractReference2LongMap<K>
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 Reference2LongOpenHashMap<K> 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.