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 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 FormAbstractReference2LongMap.BasicEntry<K>, AbstractReference2LongMap.BasicEntrySet<K>Hash.Strategy<K>Reference2LongMap.Entry<K>, Reference2LongMap.FastEntrySet<K>| Modifier and Type | Field and Description |
|---|---|
protected boolean |
containsNullKey
Whether this map contains the key zero.
|
protected Reference2LongMap.FastEntrySet<K> |
entries
Cached set of entries.
|
protected float |
f
The acceptable load factor.
|
protected K[] |
key
The array of keys.
|
protected ReferenceSet<K> |
keys
Cached set of keys.
|
protected int |
mask
The mask for wrapping a position counter.
|
protected int |
maxFill
Threshold after which we rehash.
|
protected int |
minN
We never resize below this threshold, which is the construction-time {#n}.
|
protected int |
n
The current table size.
|
protected int |
size
Number of entries in the set (including the key zero, if present).
|
protected long[] |
value
The array of values.
|
protected LongCollection |
values
Cached collection of values.
|
defRetValueDEFAULT_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 |
addTo(K 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).
|
Reference2LongOpenHashMap<K> |
clone()
Returns a deep copy of this map.
|
long |
computeLong(K k,
BiFunction<? super K,? 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 |
computeLongIfAbsent(K k,
ToLongFunction<? super K> 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 |
computeLongIfPresent(K k,
BiFunction<? super K,? 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(Object 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 |
getLong(Object k)
Returns the value to which the given key is mapped.
|
long |
getOrDefault(Object 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() |
ReferenceSet<K> |
keySet()
Returns a type-specific-set view of the keys of this map.
|
long |
mergeLong(K 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(K k,
long v)
Adds a pair to the map (optional operation).
|
void |
putAll(Map<? extends K,? extends Long> m) |
long |
putIfAbsent(K 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.
|
Reference2LongMap.FastEntrySet<K> |
reference2LongEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
protected void |
rehash(int newN)
Rehashes the map.
|
boolean |
remove(Object k,
long v)
Removes the entry for the specified key only if it is currently mapped to the specified value.
|
long |
removeLong(Object k)
Removes the mapping with the given key (optional operation).
|
long |
replace(K k,
long v)
Replaces the entry for the specified key only if it is currently mapped to some value.
|
boolean |
replace(K k,
long oldValue,
long v)
Replaces the entry for the specified key only if currently mapped to the specified value.
|
protected void |
shiftKeys(int pos)
Shifts left entries with the specified hash code, starting at the specified position,
and empties the resulting free entry.
|
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, defaultReturnValuefinalize, getClass, notify, notifyAll, wait, wait, waitcomputeLongIfAbsentPartial, containsValue, defaultReturnValue, defaultReturnValue, entrySet, get, getOrDefault, merge, put, putIfAbsent, remove, remove, replace, replaceapplyAsLongcompute, computeIfAbsent, computeIfPresent, forEach, replaceAllprotected transient K[] key
protected transient long[] value
protected transient int mask
protected transient boolean containsNullKey
protected transient int n
protected transient int maxFill
f.protected final transient int minN
protected int size
protected final float f
protected transient Reference2LongMap.FastEntrySet<K> entries
protected transient ReferenceSet<K> keys
protected transient LongCollection values
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 map.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 void putAll(Map<? extends K,? extends Long> m)
AbstractReference2LongMappublic long put(K k, long v)
Reference2LongFunctionput in interface Reference2LongFunction<K>k - the key.v - the value.Function.put(Object,Object)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.protected final void shiftKeys(int pos)
pos - a starting position.public long removeLong(Object k)
Reference2LongFunctionremoveLong in interface Reference2LongFunction<K>k - the key.Function.remove(Object)public long getLong(Object k)
Reference2LongFunctiongetLong in interface Reference2LongFunction<K>k - the key.Function.get(Object)public boolean containsKey(Object k)
Reference2LongMapcontainsKey in interface Reference2LongMap<K>containsKey in interface Map<K,Long>containsKey in class AbstractReference2LongMap<K>k - the key.key.Map.containsKey(Object)public boolean containsValue(long v)
Reference2LongMaptrue if this map maps one or more keys to the specified value.containsValue in interface Reference2LongMap<K>containsValue in class AbstractReference2LongMap<K>Map.containsValue(Object)public long getOrDefault(Object k, long defaultValue)
defaultValue if this
map contains no mapping for the key.getOrDefault in interface Reference2LongMap<K>k - 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(K k, long v)
putIfAbsent in interface Reference2LongMap<K>k - 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(Object k, long v)
remove in interface Reference2LongMap<K>k - 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(K k, long oldValue, long v)
replace in interface Reference2LongMap<K>k - 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(K k, long v)
replace in interface Reference2LongMap<K>k - key with which the specified value is associated.v - value to be associated with the specified key.Map.replace(Object, Object)public long computeLongIfAbsent(K k, ToLongFunction<? super K> 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.
computeLongIfAbsent in interface Reference2LongMap<K>k - 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 computeLongIfPresent(K k, BiFunction<? super K,? super Long,? extends Long> remappingFunction)
computeLongIfPresent in interface Reference2LongMap<K>k - 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 computeLong(K k, BiFunction<? super K,? 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.
computeLong in interface Reference2LongMap<K>k - 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 mergeLong(K 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.mergeLong in interface Reference2LongMap<K>k - 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()
Reference2LongMapclear in interface Reference2LongMap<K>clear in interface Map<K,Long>Map.clear()public int size()
Reference2LongMapInteger.MAX_VALUE elements, returns Integer.MAX_VALUE.public boolean isEmpty()
public Reference2LongMap.FastEntrySet<K> reference2LongEntrySet()
Reference2LongMapThis 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).
reference2LongEntrySet in interface Reference2LongMap<K>Map.entrySet()public ReferenceSet<K> keySet()
AbstractReference2LongMapThe 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 Reference2LongMap<K>keySet in interface Map<K,Long>keySet in class AbstractReference2LongMap<K>Map.keySet()public LongCollection values()
AbstractReference2LongMapThe 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 Reference2LongMap<K>values in interface Map<K,Long>values in class AbstractReference2LongMap<K>Map.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()protected void rehash(int newN)
This method implements the basic rehashing strategy, and may be overridden by subclasses implementing different rehashing strategies (e.g., disk-based rehashing). However, you should not override this method unless you understand the internal workings of this class.
newN - the new sizepublic 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.Copyright © 2020. All rights reserved.