public class Long2LongOpenHashMap extends AbstractLong2LongMap 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, the table is never reduced to a size smaller than that at creation time: this approach makes it possible to create maps with a large capacity in which insertions and deletions do not cause immediately rehashing. Moreover, 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 FormAbstractLong2LongMap.BasicEntryHash.Strategy<K>Long2LongMap.Entry, Long2LongMap.FastEntrySetDEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR| Constructor and Description |
|---|
Long2LongOpenHashMap()
Creates a new hash map with initial expected
Hash.DEFAULT_INITIAL_SIZE entries and
Hash.DEFAULT_LOAD_FACTOR as load factor. |
Long2LongOpenHashMap(int expected)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load
factor. |
Long2LongOpenHashMap(int expected,
float f)
Creates a new hash map.
|
Long2LongOpenHashMap(long[] k,
long[] v)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load
factor using the elements of two parallel arrays. |
Long2LongOpenHashMap(long[] k,
long[] v,
float f)
Creates a new hash map using the elements of two parallel arrays.
|
Long2LongOpenHashMap(Long2LongMap m)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load
factor copying a given type-specific one. |
Long2LongOpenHashMap(Long2LongMap m,
float f)
Creates a new hash map copying a given type-specific one.
|
Long2LongOpenHashMap(Map<? extends Long,? extends Long> m)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load
factor copying a given one. |
Long2LongOpenHashMap(Map<? extends Long,? extends Long> m,
float f)
Creates a new hash map copying a given one.
|
| Modifier and Type | Method and Description |
|---|---|
long |
addTo(long k,
long incr)
Adds an increment to value currently associated with a key.
|
void |
clear()
Removes all of the mappings from this map (optional operation).
|
Long2LongOpenHashMap |
clone()
Returns a deep copy of this map.
|
long |
compute(long k,
BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
Attempts to compute a mapping for the specified key and its current
mapped value (or
null if there is no current mapping). |
long |
computeIfAbsent(long k,
LongUnaryOperator mappingFunction)
If the specified key is not already associated with a value, attempts to
compute its value using the given mapping function and enters it into
this map.
|
long |
computeIfAbsentNullable(long k,
LongFunction<? extends Long> mappingFunction)
If the specified key is not already associated with a value, attempts to
compute its value using the given mapping function and enters it into
this map unless it is
null. |
long |
computeIfPresent(long k,
BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
If the value for the specified key is present, attempts to compute a new
mapping given the key and its current mapped value.
|
boolean |
containsKey(long k)
Returns true if this function contains a mapping for the specified key.
|
boolean |
containsValue(long v)
Returns
true if this map maps one or more keys to the specified
value. |
long |
get(long k)
Returns the value to which the given key is mapped.
|
long |
getOrDefault(long k,
long defaultValue)
Returns the value to which the specified key is mapped, or the
defaultValue if this map contains no mapping for the key. |
int |
hashCode()
Returns a hash code for this map.
|
boolean |
isEmpty()
Returns true if this map contains no key-value mappings.
|
LongSet |
keySet()
Returns a type-specific-set view of the keys of this map.
|
Long2LongMap.FastEntrySet |
long2LongEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
long |
merge(long k,
long v,
BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
If the specified key is not already associated with a value, associates
it with the given
value. |
long |
put(long k,
long v)
Adds a pair to the map (optional operation).
|
void |
putAll(Map<? extends Long,? extends Long> m)
Copies all of the mappings from the specified map to this map
(optional operation).
|
long |
putIfAbsent(long k,
long v)
If the specified key is not already associated with a value, associates
it with the given value and returns the default return value, else returns the current value.
|
long |
remove(long k)
Removes the mapping with the given key (optional operation).
|
boolean |
remove(long k,
long v)
Removes the entry for the specified key only if it is currently mapped to
the specified value.
|
long |
replace(long k,
long v)
Replaces the entry for the specified key only if it is currently mapped
to some value.
|
boolean |
replace(long k,
long oldValue,
long v)
Replaces the entry for the specified key only if currently mapped to the
specified value.
|
int |
size()
Returns the number of key/value mappings in this map.
|
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.
|
equals, toStringdefaultReturnValue, defaultReturnValuecompute, computeIfAbsent, computeIfAbsentPartial, computeIfPresent, containsKey, containsValue, defaultReturnValue, defaultReturnValue, entrySet, get, getOrDefault, merge, put, putIfAbsent, remove, remove, replace, replaceapplyAsLongandThen, compose, identityforEach, replaceAllpublic Long2LongOpenHashMap(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 map.f - the load factor.public Long2LongOpenHashMap(int expected)
Hash.DEFAULT_LOAD_FACTOR as load
factor.expected - the expected number of elements in the hash map.public Long2LongOpenHashMap()
Hash.DEFAULT_INITIAL_SIZE entries and
Hash.DEFAULT_LOAD_FACTOR as load factor.public Long2LongOpenHashMap(Map<? extends Long,? extends Long> m, float f)
m - a Map to be copied into the new hash map.f - the load factor.public Long2LongOpenHashMap(Map<? extends Long,? 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 Long2LongOpenHashMap(Long2LongMap m, float f)
m - a type-specific map to be copied into the new hash map.f - the load factor.public Long2LongOpenHashMap(Long2LongMap 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 Long2LongOpenHashMap(long[] 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 Long2LongOpenHashMap(long[] 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 void putAll(Map<? extends Long,? extends Long> m)
AbstractLong2LongMapput(k, v) on this map once
for each mapping from key k to value v in the
specified map. The behavior of this operation is undefined if the
specified map is modified while the operation is in progress.public long put(long k,
long v)
Long2LongFunctionput in interface Long2LongFunctionk - the key.v - the value.Function.put(Object,Object)public long addTo(long 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 remove(long k)
Long2LongFunctionremove in interface Long2LongFunctionk - the key.Function.remove(Object)public long get(long k)
Long2LongFunctionget in interface Long2LongFunctionk - the key.Function.get(Object)public boolean containsKey(long k)
Long2LongMapcontainsKey in interface Long2LongFunctioncontainsKey in interface Long2LongMapcontainsKey in class AbstractLong2LongMapk - the key.key.Map.containsKey(Object)public boolean containsValue(long v)
Long2LongMaptrue if this map maps one or more keys to the specified
value.containsValue in interface Long2LongMapcontainsValue in class AbstractLong2LongMapMap.containsValue(Object)public long getOrDefault(long k,
long defaultValue)
defaultValue if this map contains no mapping for the key.getOrDefault in interface Long2LongMapk - the key.defaultValue - the default mapping of the key.defaultValue if this map contains no mapping for the key.Map.getOrDefault(Object, Object)public long putIfAbsent(long k,
long v)
putIfAbsent in interface Long2LongMapk - key with which the specified value is to be associated.v - value to be associated with the specified key.Map.putIfAbsent(Object, Object)public boolean remove(long k,
long v)
remove in interface Long2LongMapk - key with which the specified value is associated.v - value expected to be associated with the specified key.true if the value was removed.Map.remove(Object, Object)public boolean replace(long k,
long oldValue,
long v)
replace in interface Long2LongMapk - key with which the specified value is associated.oldValue - value expected to be associated with the specified key.v - value to be associated with the specified key.true if the value was replaced.Map.replace(Object, Object, Object)public long replace(long k,
long v)
replace in interface Long2LongMapk - key with which the specified value is associated.v - value to be associated with the specified key.Map.replace(Object, Object)public long computeIfAbsent(long k,
LongUnaryOperator mappingFunction)
Note that contrarily to the default
computeIfAbsent(), it is not possible to not add a value for a given
key, since the mappingFunction cannot return null. If
such a behavior is needed, please use the corresponding nullable
version.
computeIfAbsent in interface Long2LongMapk - key with which the specified value is to be associated.mappingFunction - the function to compute a value.Map.computeIfAbsent(Object, java.util.function.Function)public long computeIfAbsentNullable(long k,
LongFunction<? extends Long> mappingFunction)
null.
Note that this version of
computeIfAbsent() should be used only if you plan to return null
in the mapping function.
computeIfAbsentNullable in interface Long2LongMapk - key with which the specified value is to be associated.mappingFunction - the function to compute a value.null.Map.computeIfAbsent(Object, java.util.function.Function)public long computeIfPresent(long k,
BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
computeIfPresent in interface Long2LongMapk - key with which the specified value is to be associated.remappingFunction - the function to compute a value.Map.computeIfPresent(Object,
java.util.function.BiFunction)public long compute(long k,
BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
null if there is no current mapping).
If the function returns null, the mapping is removed (or remains
absent if initially absent). If the function itself throws an (unchecked)
exception, the exception is rethrown, and the current mapping is left
unchanged.
compute in interface Long2LongMapk - key with which the specified value is to be associated.remappingFunction - the function to compute a value.Map.compute(Object, java.util.function.BiFunction)public long merge(long k,
long v,
BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
value. Otherwise, replaces the associated value
with the results of the given remapping function, or removes if the
result is null.merge in interface Long2LongMapk - key with which the resulting value is to be associated.v - the value to be merged with the existing value associated with
the key or, if no existing value is associated with the key,
to be associated with the key.remappingFunction - the function to recompute a value if present.Map.merge(Object, Object, java.util.function.BiFunction)public void clear()
Long2LongMapclear in interface Long2LongMapclear in interface Map<Long,Long>Map.clear()public int size()
Long2LongMapInteger.MAX_VALUE elements, returns
Integer.MAX_VALUE.public boolean isEmpty()
java.util.Mappublic Long2LongMap.FastEntrySet long2LongEntrySet()
Long2LongMap
This method is necessary because there is no inheritance along type
parameters: it is thus impossible to strengthen Map.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).
long2LongEntrySet in interface Long2LongMapMap.entrySet()public LongSet keySet()
AbstractLong2LongMap
The view is backed by the set returned by Map.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 Long2LongMapkeySet in interface Map<Long,Long>keySet in class AbstractLong2LongMapMap.keySet()public LongCollection values()
AbstractLong2LongMap
The view is backed by the set returned by Map.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 Long2LongMapvalues in interface Map<Long,Long>values in class AbstractLong2LongMapMap.values()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 Long2LongOpenHashMap 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.hashCode in interface Map<Long,Long>hashCode in class AbstractLong2LongMapObject.equals(java.lang.Object),
System.identityHashCode(java.lang.Object)