Reference2LongMaps.SynchronizedMap (fastutil 8.1.0)

java.lang.Object
- it.unimi.dsi.fastutil.objects.Reference2LongFunctions.SynchronizedFunction<K>
- - it.unimi.dsi.fastutil.objects.Reference2LongMaps.SynchronizedMap<K>

All Implemented Interfaces:

Reference2LongFunction<K>, Reference2LongMap<K>, Serializable, Function<K,Long>, ToLongFunction<K>, Map<K,Long>

Direct Known Subclasses:

Reference2LongSortedMaps.SynchronizedSortedMap

Enclosing class:

Reference2LongMaps
```
public static class Reference2LongMaps.SynchronizedMap<K>
extends Reference2LongFunctions.SynchronizedFunction<K>
implements Reference2LongMap<K>, Serializable
```
A synchronized wrapper class for maps.

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.objects.Reference2LongMap
  Reference2LongMap.Entry<K>, Reference2LongMap.FastEntrySet<K>

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`Long`	`compute(K key, 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`	`computeIfAbsent(K key, Function<? super K,? extends Long> mappingFunction)` If the specified key is not already associated with a value (or is mapped to `null`), attempts to compute its value using the given mapping function and enters it into this map unless `null`.
`Long`	`computeIfPresent(K key, BiFunction<? super K,? super Long,? extends Long> remappingFunction)` If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.
`long`	`computeLong(K key, 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 key, 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`	`computeLongIfAbsentPartial(K key, Reference2LongFunction<? 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, unless the key is not present in the given mapping function.
`long`	`computeLongIfPresent(K key, 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`	`containsValue(long v)` Returns `true` if this map maps one or more keys to the specified value.
`boolean`	`containsValue(Object ov)` Deprecated. Please use the corresponding type-specific method instead.
`ObjectSet<Map.Entry<K,Long>>`	`entrySet()` Deprecated. Please use the corresponding type-specific method instead.
`boolean`	`equals(Object o)` Indicates whether some other object is "equal to" this one.
`void`	`forEach(BiConsumer<? super K,? super Long> action)` Performs the given action for each entry in this map until all entries have been processed or the action throws an exception.
`long`	`getOrDefault(Object key, long defaultValue)` Returns the value to which the specified key is mapped, or the `defaultValue` if this map contains no mapping for the key.
`Long`	`getOrDefault(Object key, Long defaultValue)` Deprecated. Please use the corresponding type-specific method instead.
`int`	`hashCode()` Returns a hash code value for the object.
`boolean`	`isEmpty()` Returns `true` if this map contains no key-value mappings.
`ReferenceSet<K>`	`keySet()` Returns a `Set` view of the keys contained in this map.
`Long`	`merge(K key, Long value, BiFunction<? super Long,? super Long,? extends Long> remappingFunction)` Deprecated. Please use the corresponding type-specific method instead.
`long`	`mergeLong(K key, long value, 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`.
`void`	`putAll(Map<? extends K,? extends Long> m)` Copies all of the mappings from the specified map to this map (optional operation).
`long`	`putIfAbsent(K key, long value)` 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`	`putIfAbsent(K key, Long value)` Deprecated. Please use the corresponding type-specific method instead.
`ObjectSet<Reference2LongMap.Entry<K>>`	`reference2LongEntrySet()` Returns a type-specific set view of the mappings contained in this map.
`boolean`	`remove(Object key, long value)` Removes the entry for the specified key only if it is currently mapped to the specified value.
`boolean`	`remove(Object key, Object value)` Deprecated. Please use the corresponding type-specific method instead.
`long`	`replace(K key, long value)` Replaces the entry for the specified key only if it is currently mapped to some value.
`Long`	`replace(K key, Long value)` Deprecated. Please use the corresponding type-specific method instead.
`boolean`	`replace(K key, long oldValue, long newValue)` Replaces the entry for the specified key only if currently mapped to the specified value.
`boolean`	`replace(K key, Long oldValue, Long newValue)` Deprecated. Please use the corresponding type-specific method instead.
`void`	`replaceAll(BiFunction<? super K,? super Long,? extends Long> function)` Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception.
`LongCollection`	`values()` Returns a `Collection` view of the values contained in this map.

Methods inherited from class it.unimi.dsi.fastutil.objects.Reference2LongFunctions.SynchronizedFunction
apply, applyAsLong, clear, containsKey, defaultReturnValue, defaultReturnValue, get, getLong, put, put, remove, removeLong, size, toString

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2LongMap
clear, containsKey, defaultReturnValue, defaultReturnValue, get, put, remove, size

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2LongFunction
applyAsLong, getLong, put, removeLong

Methods inherited from interface it.unimi.dsi.fastutil.Function
apply

Methods inherited from interface java.util.function.Function
andThen, compose, identity

- Method Detail
  - containsValue
```
public boolean containsValue(long v)
```
    Description copied from interface: Reference2LongMap
    
    Returns true if this map maps one or more keys to the specified value.
    
    Specified by:
    
    containsValue in interface Reference2LongMap<K>
    
    See Also:
    
    Map.containsValue(Object)
  - containsValue
```
@Deprecated
public boolean containsValue(Object ov)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that (value==null ? v==null : value.equals(v)). This operation will probably require time linear in the map size for most implementations of the Map interface.
    
    Specified by:
    
    containsValue in interface Reference2LongMap<K>
    
    Specified by:
    
    containsValue in interface Map<K,Long>
    
    Parameters:
    
    ov - value whose presence in this map is to be tested
    
    Returns:
    
    true if this map maps one or more keys to the specified value
  - putAll
```
public void putAll(Map<? extends K,? extends Long> m)
```
    Description copied from interface: java.util.Map
    
    Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(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.
    
    Specified by:
    
    putAll in interface Map<K,Long>
    
    Parameters:
    
    m - mappings to be stored in this map
  - reference2LongEntrySet
```
public ObjectSet<Reference2LongMap.Entry<K>> reference2LongEntrySet()
```
    Description copied from interface: Reference2LongMap
    
    Returns a type-specific set view of the mappings contained in this map.
    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).
    
    Specified by:
    
    reference2LongEntrySet in interface Reference2LongMap<K>
    
    Returns:
    
    a type-specific set view of the mappings contained in this map.
    
    See Also:
    
    Map.entrySet()
  - entrySet
```
@Deprecated
public ObjectSet<Map.Entry<K,Long>> entrySet()
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    Returns a set view of the mappings contained in this map.
    Note that this specification strengthens the one given in Map.entrySet().
    
    Specified by:
    
    entrySet in interface Reference2LongMap<K>
    
    Specified by:
    
    entrySet in interface Map<K,Long>
    
    Returns:
    
    a set view of the mappings contained in this map.
    
    See Also:
    
    Map.entrySet()
  - keySet
```
public ReferenceSet<K> keySet()
```
    Description copied from interface: Reference2LongMap
    
    Returns a Set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.
    Note that this specification strengthens the one given in Map.keySet().
    
    Specified by:
    
    keySet in interface Reference2LongMap<K>
    
    Specified by:
    
    keySet in interface Map<K,Long>
    
    Returns:
    
    a set view of the keys contained in this map.
    
    See Also:
    
    Map.keySet()
  - values
```
public LongCollection values()
```
    Description copied from interface: Reference2LongMap
    
    Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.
    Note that this specification strengthens the one given in Map.values().
    
    Specified by:
    
    values in interface Reference2LongMap<K>
    
    Specified by:
    
    values in interface Map<K,Long>
    
    Returns:
    
    a set view of the values contained in this map.
    
    See Also:
    
    Map.values()
  - isEmpty
```
public boolean isEmpty()
```
    Description copied from interface: java.util.Map
    
    Returns true if this map contains no key-value mappings.
    
    Specified by:
    
    isEmpty in interface Map<K,Long>
    
    Returns:
    
    true if this map contains no key-value mappings
  - hashCode
```
public int hashCode()
```
    Description copied from class: java.lang.Object
    Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.
    The general contract of hashCode is:
    - Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
    - If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
    - It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
    As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)
    Specified by:
    
    hashCode in interface Map<K,Long>
    
    Overrides:
    
    hashCode in class Reference2LongFunctions.SynchronizedFunction<K>
    
    Returns:
    
    a hash code value for this object.
    
    See Also:
    
    Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)
  - equals
```
public boolean equals(Object o)
```
    Description copied from class: java.lang.Object
    Indicates whether some other object is "equal to" this one.
    The equals method implements an equivalence relation on non-null object references:
    - It is reflexive: for any non-null reference value x, x.equals(x) should return true.
    - It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
    - It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
    - It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
    - For any non-null reference value x, x.equals(null) should return false.
    The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).
    Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
    Specified by:
    
    equals in interface Map<K,Long>
    
    Overrides:
    
    equals in class Reference2LongFunctions.SynchronizedFunction<K>
    
    Parameters:
    
    o - the reference object with which to compare.
    
    Returns:
    
    true if this object is the same as the obj argument; false otherwise.
    
    See Also:
    
    Object.hashCode(), HashMap
  - getOrDefault
```
public long getOrDefault(Object key,
                         long defaultValue)
```
    Description copied from interface: Reference2LongMap
    
    Returns the value to which the specified key is mapped, or the defaultValue if this map contains no mapping for the key.
    
    Specified by:
    
    getOrDefault in interface Reference2LongMap<K>
    
    Parameters:
    
    key - the key.
    
    defaultValue - the default mapping of the key.
    
    Returns:
    
    the value to which the specified key is mapped, or the defaultValue if this map contains no mapping for the key.
    
    See Also:
    
    Map.getOrDefault(Object, Object)
  - forEach
```
public void forEach(BiConsumer<? super K,? super Long> action)
```
    Description copied from interface: java.util.Map
    
    Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. Unless otherwise specified by the implementing class, actions are performed in the order of entry set iteration (if an iteration order is specified.) Exceptions thrown by the action are relayed to the caller.
    
    Specified by:
    
    forEach in interface Map<K,Long>
    
    Parameters:
    
    action - The action to be performed for each entry
  - replaceAll
```
public void replaceAll(BiFunction<? super K,? super Long,? extends Long> function)
```
    Description copied from interface: java.util.Map
    
    Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception. Exceptions thrown by the function are relayed to the caller.
    
    Specified by:
    
    replaceAll in interface Map<K,Long>
    
    Parameters:
    
    function - the function to apply to each entry
  - putIfAbsent
```
public long putIfAbsent(K key,
                        long value)
```
    Description copied from interface: Reference2LongMap
    
    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.
    
    Specified by:
    
    putIfAbsent in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is to be associated.
    
    value - value to be associated with the specified key.
    
    Returns:
    
    the previous value associated with the specified key, or the default return value if there was no mapping for the key.
    
    See Also:
    
    Map.putIfAbsent(Object, Object)
  - remove
```
public boolean remove(Object key,
                      long value)
```
    Description copied from interface: Reference2LongMap
    
    Removes the entry for the specified key only if it is currently mapped to the specified value.
    
    Specified by:
    
    remove in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is associated.
    
    value - value expected to be associated with the specified key.
    
    Returns:
    
    true if the value was removed.
    
    See Also:
    
    Map.remove(Object, Object)
  - replace
```
public long replace(K key,
                    long value)
```
    Description copied from interface: Reference2LongMap
    
    Replaces the entry for the specified key only if it is currently mapped to some value.
    
    Specified by:
    
    replace in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is associated.
    
    value - value to be associated with the specified key.
    
    Returns:
    
    the previous value associated with the specified key, or the default return value if there was no mapping for the key.
    
    See Also:
    
    Map.replace(Object, Object)
  - replace
```
public boolean replace(K key,
                       long oldValue,
                       long newValue)
```
    Description copied from interface: Reference2LongMap
    
    Replaces the entry for the specified key only if currently mapped to the specified value.
    
    Specified by:
    
    replace in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is associated.
    
    oldValue - value expected to be associated with the specified key.
    
    newValue - value to be associated with the specified key.
    
    Returns:
    
    true if the value was replaced.
    
    See Also:
    
    Map.replace(Object, Object, Object)
  - computeLongIfAbsent
```
public long computeLongIfAbsent(K key,
                                ToLongFunction<? super K> mappingFunction)
```
    Description copied from interface: Reference2LongMap
    
    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.
    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.
    
    Specified by:
    
    computeLongIfAbsent in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is to be associated.
    
    mappingFunction - the function to compute a value.
    
    Returns:
    
    the current (existing or computed) value associated with the specified key.
    
    See Also:
    
    Map.computeIfAbsent(Object, java.util.function.Function)
  - computeLongIfAbsentPartial
```
public long computeLongIfAbsentPartial(K key,
                                       Reference2LongFunction<? super K> mappingFunction)
```
    Description copied from interface: Reference2LongMap
    
    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 the key is not present in the given mapping function.
    This version of computeIfAbsent() uses a type-specific version of fastutil's Function. Since Function has a containsKey() method, it is possible to avoid adding a key by having containsKey() return false for that key.
    
    Specified by:
    
    computeLongIfAbsentPartial in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is to be associated.
    
    mappingFunction - the function to compute a value.
    
    Returns:
    
    the current (existing or computed) value associated with the specified key.
    
    See Also:
    
    Map.computeIfAbsent(Object, java.util.function.Function)
  - computeLongIfPresent
```
public long computeLongIfPresent(K key,
                                 BiFunction<? super K,? super Long,? extends Long> remappingFunction)
```
    Description copied from interface: Reference2LongMap
    
    If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.
    
    Specified by:
    
    computeLongIfPresent in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is to be associated.
    
    remappingFunction - the function to compute a value.
    
    Returns:
    
    the new value associated with the specified key, or the default return value if none.
    
    See Also:
    
    Map.computeIfPresent(Object, java.util.function.BiFunction)
  - computeLong
```
public long computeLong(K key,
                        BiFunction<? super K,? super Long,? extends Long> remappingFunction)
```
    Description copied from interface: Reference2LongMap
    
    Attempts to compute a mapping for the specified key and its current mapped value (or 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.
    
    Specified by:
    
    computeLong in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the specified value is to be associated.
    
    remappingFunction - the function to compute a value.
    
    Returns:
    
    the new value associated with the specified key, or the default return value if none.
    
    See Also:
    
    Map.compute(Object, java.util.function.BiFunction)
  - mergeLong
```
public long mergeLong(K key,
                      long value,
                      BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
```
    Description copied from interface: Reference2LongMap
    
    If the specified key is not already associated with a value, associates it with the given value. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is null.
    
    Specified by:
    
    mergeLong in interface Reference2LongMap<K>
    
    Parameters:
    
    key - key with which the resulting value is to be associated.
    
    value - 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.
    
    Returns:
    
    the new value associated with the specified key, or the default return value if no value is associated with the key.
    
    See Also:
    
    Map.merge(Object, Object, java.util.function.BiFunction)
  - getOrDefault
```
@Deprecated
public Long getOrDefault(Object key,
                                     Long defaultValue)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    Returns the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key.
    This default implementation just delegates to the corresponding Map method.
    
    Specified by:
    
    getOrDefault in interface Reference2LongMap<K>
    
    Specified by:
    
    getOrDefault in interface Map<K,Long>
    
    Parameters:
    
    key - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key
  - remove
```
@Deprecated
public boolean remove(Object key,
                                  Object value)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    Removes the entry for the specified key only if it is currently mapped to the specified value.
    This default implementation just delegates to the corresponding Map method.
    
    Specified by:
    
    remove in interface Reference2LongMap<K>
    
    Specified by:
    
    remove in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the specified value is associated
    
    value - value expected to be associated with the specified key
    
    Returns:
    
    true if the value was removed
  - replace
```
@Deprecated
public Long replace(K key,
                                Long value)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    Replaces the entry for the specified key only if it is currently mapped to some value.
    This default implementation just delegates to the corresponding Map method.
    
    Specified by:
    
    replace in interface Reference2LongMap<K>
    
    Specified by:
    
    replace in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the specified value is associated
    
    value - value to be associated with the specified key
    
    Returns:
    
    the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.)
  - replace
```
@Deprecated
public boolean replace(K key,
                                   Long oldValue,
                                   Long newValue)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    Replaces the entry for the specified key only if currently mapped to the specified value.
    This default implementation just delegates to the corresponding Map method.
    
    Specified by:
    
    replace in interface Reference2LongMap<K>
    
    Specified by:
    
    replace in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the specified value is associated
    
    oldValue - value expected to be associated with the specified key
    
    newValue - value to be associated with the specified key
    
    Returns:
    
    true if the value was replaced
  - putIfAbsent
```
@Deprecated
public Long putIfAbsent(K key,
                                    Long value)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    If the specified key is not already associated with a value (or is mapped to null) associates it with the given value and returns null, else returns the current value.
    This default implementation just delegates to the corresponding Map method.
    
    Specified by:
    
    putIfAbsent in interface Reference2LongMap<K>
    
    Specified by:
    
    putIfAbsent in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the specified value is to be associated
    
    value - value to be associated with the specified key
    
    Returns:
    
    the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.)
  - computeIfAbsent
```
public Long computeIfAbsent(K key,
                            Function<? super K,? extends Long> mappingFunction)
```
    Description copied from interface: java.util.Map
    If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null.
    If the function returns null no mapping is recorded. If the function itself throws an (unchecked) exception, the exception is rethrown, and no mapping is recorded. The most common usage is to construct a new object serving as an initial mapped value or memoized result, as in:
```
 
 map.computeIfAbsent(key, k -> new Value(f(k)));
 
```
    Or to implement a multi-value map, Map<K,Collection<V>>, supporting multiple values per key:
```
 
 map.computeIfAbsent(key, k -> new HashSet<V>()).add(v);
 
```
    Specified by:
    
    computeIfAbsent in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the specified value is to be associated
    
    mappingFunction - the function to compute a value
    
    Returns:
    
    the current (existing or computed) value associated with the specified key, or null if the computed value is null
  - computeIfPresent
```
public Long computeIfPresent(K key,
                             BiFunction<? super K,? super Long,? extends Long> remappingFunction)
```
    Description copied from interface: java.util.Map
    
    If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.
    If the function returns null, the mapping is removed. If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.
    
    Specified by:
    
    computeIfPresent in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the specified value is to be associated
    
    remappingFunction - the function to compute a value
    
    Returns:
    
    the new value associated with the specified key, or null if none
  - compute
```
public Long compute(K key,
                    BiFunction<? super K,? super Long,? extends Long> remappingFunction)
```
    Description copied from interface: java.util.Map
    Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping). For example, to either create or append a String msg to a value mapping:
```
 
 map.compute(key, (k, v) -> (v == null) ? msg : v.concat(msg))
```
    (Method merge() is often simpler to use for such purposes.)
    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.
    Specified by:
    
    compute in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the specified value is to be associated
    
    remappingFunction - the function to compute a value
    
    Returns:
    
    the new value associated with the specified key, or null if none
  - merge
```
@Deprecated
public Long merge(K key,
                              Long value,
                              BiFunction<? super Long,? super Long,? extends Long> remappingFunction)
```
    Deprecated. Please use the corresponding type-specific method instead.
    If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is null. This method may be of use when combining multiple mapped values for a key. For example, to either create or append a String msg to a value mapping:
```
 
 map.merge(key, msg, String::concat)
 
```
    If the function returns null the mapping is removed. If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.
    This default implementation just delegates to the corresponding Map method.
    Specified by:
    
    merge in interface Reference2LongMap<K>
    
    Specified by:
    
    merge in interface Map<K,Long>
    
    Parameters:
    
    key - key with which the resulting value is to be associated
    
    value - the non-null value to be merged with the existing value associated with the key or, if no existing value or a null value is associated with the key, to be associated with the key
    
    remappingFunction - the function to recompute a value if present
    
    Returns:
    
    the new value associated with the specified key, or null if no value is associated with the key

Class Reference2LongMaps.SynchronizedMap<K>

Nested Class Summary

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.objects.Reference2LongMap

Method Summary

Methods inherited from class it.unimi.dsi.fastutil.objects.Reference2LongFunctions.SynchronizedFunction

Methods inherited from class java.lang.Object

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2LongMap

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2LongFunction

Methods inherited from interface it.unimi.dsi.fastutil.Function

Methods inherited from interface java.util.function.Function

Method Detail

containsValue

containsValue

putAll

reference2LongEntrySet

entrySet

keySet

values

isEmpty

hashCode

equals

getOrDefault

forEach

replaceAll

putIfAbsent

remove

replace

replace

computeLongIfAbsent

computeLongIfAbsentPartial

computeLongIfPresent

computeLong

mergeLong

getOrDefault

remove

replace

replace

putIfAbsent

computeIfAbsent

computeIfPresent

compute

merge