Package com.google.common.collect

Class ConcurrentHashMultiset<E>

java.lang.Object
java.util.AbstractCollection<E>
com.google.common.collect.ConcurrentHashMultiset<E>
All Implemented Interfaces:
Multiset<E>, Serializable, Iterable<E>, Collection<E>
@Deprecated(since="2022-12-01") public final class ConcurrentHashMultiset<E> extends AbstractCollection<E> implements Serializable
Deprecated.
The Google Guava Core Libraries are deprecated and will not be part of the AEM SDK after April 2023
A multiset that supports concurrent modifications and that provides atomic versions of most Multiset operations (exceptions where noted). Null elements are not supported.

See the Guava User Guide article on Multiset.

Since:
2.0 (imported from Google Collections Library)
See Also:

  • Nested Class Summary

    Nested classes/interfaces inherited from interface com.google.common.collect.Multiset

    Multiset.Entry<E>

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    add(E element)
    Deprecated.
    Adds a single occurrence of the specified element to this multiset.
    int
    add(E element, int occurrences)
    Deprecated.
    Adds a number of occurrences of the specified element to this multiset.
    boolean
    addAll(Collection<? extends E> elementsToAdd)
    Deprecated.
    void
    clear()
    Deprecated.
     
    boolean
    contains(Object element)
    Deprecated.
    Determines whether this multiset contains the specified element.
    int
    count(Object element)
    Deprecated.
    Returns the number of occurrences of element in this multiset.
    static <E> ConcurrentHashMultiset<E>
    create()
    Deprecated.
    Creates a new, empty ConcurrentHashMultiset using the default initial capacity, load factor, and concurrency settings.
    static <E> ConcurrentHashMultiset<E>
    create(MapMaker mapMaker)
    Deprecated.
    Creates a new, empty ConcurrentHashMultiset using mapMaker to construct the internal backing map.
    static <E> ConcurrentHashMultiset<E>
    create(Iterable<? extends E> elements)
    Deprecated.
    Creates a new ConcurrentHashMultiset containing the specified elements, using the default initial capacity, load factor, and concurrency settings.
    Set<E>
    elementSet()
    Deprecated.
    Returns the set of distinct elements contained in this multiset.
    Set<Multiset.Entry<E>>
    entrySet()
    Deprecated.
    Returns a view of the contents of this multiset, grouped into Multiset.Entry instances, each providing an element of the multiset and the count of that element.
    boolean
    equals(Object object)
    Deprecated.
    Compares the specified object with this multiset for equality.
    int
    hashCode()
    Deprecated.
    Returns the hash code for this multiset.
    boolean
    isEmpty()
    Deprecated.
     
    Iterator<E>
    iterator()
    Deprecated.
    boolean
    remove(Object element)
    Deprecated.
    Removes a single occurrence of the specified element from this multiset, if present.
    int
    remove(Object element, int occurrences)
    Deprecated.
    Removes a number of occurrences of the specified element from this multiset.
    boolean
    removeAll(Collection<?> elementsToRemove)
    Deprecated.
    boolean
    removeExactly(Object element, int occurrences)
    Deprecated.
    Removes exactly the specified number of occurrences of element, or makes no change if this is not possible.
    boolean
    retainAll(Collection<?> elementsToRetain)
    Deprecated.
    int
    setCount(E element, int count)
    Deprecated.
    Adds or removes occurrences of element such that the count(java.lang.Object) of the element becomes count.
    boolean
    setCount(E element, int expectedOldCount, int newCount)
    Deprecated.
    Sets the number of occurrences of element to newCount, but only if the count is currently expectedOldCount.
    int
    size()
    Deprecated.
    Object[]
    toArray()
    Deprecated.
     
    <T> T[]
    toArray(T[] array)
    Deprecated.
     
    String
    toString()
    Deprecated.

    Methods inherited from class java.util.AbstractCollection

    containsAll

    Methods inherited from class java.lang.Object

    getClass, notify, notifyAll, wait, wait, wait

    Methods inherited from interface java.util.Collection

    parallelStream, removeIf, spliterator, stream, toArray

    Methods inherited from interface java.lang.Iterable

    forEach

    Methods inherited from interface com.google.common.collect.Multiset

    containsAll

  • Method Details

    • create

      public static <E> ConcurrentHashMultiset<E> create()
      Deprecated.
      Creates a new, empty ConcurrentHashMultiset using the default initial capacity, load factor, and concurrency settings.

    • create

      public static <E> ConcurrentHashMultiset<E> create(Iterable<? extends E> elements)
      Deprecated.
      Creates a new ConcurrentHashMultiset containing the specified elements, using the default initial capacity, load factor, and concurrency settings.

      This implementation is highly efficient when elements is itself a Multiset.

      Parameters:
      elements - the elements that the multiset should contain

    • create

      @Beta public static <E> ConcurrentHashMultiset<E> create(MapMaker mapMaker)
      Deprecated.
      Creates a new, empty ConcurrentHashMultiset using mapMaker to construct the internal backing map.

      If this MapMaker is configured to use entry eviction of any kind, this eviction applies to all occurrences of a given element as a single unit. However, most updates to the multiset do not count as map updates at all, since we're usually just mutating the value stored in the map, so MapMaker.expireAfterAccess(long, java.util.concurrent.TimeUnit) makes sense (evict the entry that was queried or updated longest ago), but MapMaker.expireAfterWrite(long, java.util.concurrent.TimeUnit) doesn't, because the eviction time is measured from when we saw the first occurrence of the object.

      The returned multiset is serializable but any serialization caveats given in MapMaker apply.

      Finally, soft/weak values can be used but are not very useful: the values are created internally and not exposed externally, so no one else will have a strong reference to the values. Weak keys on the other hand can be useful in some scenarios.

      Since:
      15.0 (source compatible (accepting the since removed GenericMapMaker class) since 7.0)

    • count

      public int count(@Nullable Object element)
      Deprecated.
      Returns the number of occurrences of element in this multiset.
      Specified by:
      count in interface Multiset<E>
      Parameters:
      element - the element to look for
      Returns:
      the nonnegative number of occurrences of the element

    • size

      public int size()
      Deprecated.

      If the data in the multiset is modified by any other threads during this method, it is undefined which (if any) of these modifications will be reflected in the result.

      Specified by:
      size in interface Collection<E>

    • toArray

      public Object[] toArray()
      Deprecated.
      Specified by:
      toArray in interface Collection<E>
      Overrides:
      toArray in class AbstractCollection<E>

    • toArray

      public <T> T[] toArray(T[] array)
      Deprecated.
      Specified by:
      toArray in interface Collection<E>
      Overrides:
      toArray in class AbstractCollection<E>

    • add

      public int add(E element, int occurrences)
      Deprecated.
      Adds a number of occurrences of the specified element to this multiset.
      Specified by:
      add in interface Multiset<E>
      Parameters:
      element - the element to add
      occurrences - the number of occurrences to add
      Returns:
      the previous count of the element before the operation; possibly zero
      Throws:
      IllegalArgumentException - if occurrences is negative, or if the resulting amount would exceed Integer.MAX_VALUE

    • remove

      public int remove(@Nullable Object element, int occurrences)
      Deprecated.
      Removes a number of occurrences of the specified element from this multiset. If the multiset contains fewer than this number of occurrences to begin with, all occurrences will be removed.
      Specified by:
      remove in interface Multiset<E>
      Parameters:
      element - the element whose occurrences should be removed
      occurrences - the number of occurrences of the element to remove
      Returns:
      the count of the element before the operation; possibly zero
      Throws:
      IllegalArgumentException - if occurrences is negative

    • removeExactly

      public boolean removeExactly(@Nullable Object element, int occurrences)
      Deprecated.
      Removes exactly the specified number of occurrences of element, or makes no change if this is not possible.

      This method, in contrast to remove(Object, int), has no effect when the element count is smaller than occurrences.

      Parameters:
      element - the element to remove
      occurrences - the number of occurrences of element to remove
      Returns:
      true if the removal was possible (including if occurrences is zero)

    • setCount

      public int setCount(E element, int count)
      Deprecated.
      Adds or removes occurrences of element such that the count(java.lang.Object) of the element becomes count.
      Specified by:
      setCount in interface Multiset<E>
      Parameters:
      element - the element to add or remove occurrences of; may be null only if explicitly allowed by the implementation
      count - the desired count of the element in this multiset
      Returns:
      the count of element in the multiset before this call
      Throws:
      IllegalArgumentException - if count is negative

    • setCount

      public boolean setCount(E element, int expectedOldCount, int newCount)
      Deprecated.
      Sets the number of occurrences of element to newCount, but only if the count is currently expectedOldCount. If element does not appear in the multiset exactly expectedOldCount times, no changes will be made.
      Specified by:
      setCount in interface Multiset<E>
      Parameters:
      element - the element to conditionally set the count of; may be null only if explicitly allowed by the implementation
      expectedOldCount - the expected present count of the element in this multiset
      newCount - the desired count of the element in this multiset
      Returns:
      true if the change was successful. This usually indicates that the multiset has been modified, but not always: in the case that expectedOldCount == newCount, the method will return true if the condition was met.
      Throws:
      IllegalArgumentException - if expectedOldCount or newCount is negative

    • entrySet

      public Set<Multiset.Entry<E>> entrySet()
      Deprecated.
      Description copied from interface: Multiset
      Returns a view of the contents of this multiset, grouped into Multiset.Entry instances, each providing an element of the multiset and the count of that element. This set contains exactly one entry for each distinct element in the multiset (thus it always has the same size as the Multiset.elementSet()). The order of the elements in the element set is unspecified.

      The entry set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. However, multiset changes may or may not be reflected in any Entry instances already retrieved from the entry set (this is implementation-dependent). Furthermore, implementations are not required to support modifications to the entry set at all, and the Entry instances themselves don't even have methods for modification. See the specific implementation class for more details on how its entry set handles modifications.

      Specified by:
      entrySet in interface Multiset<E>
      Returns:
      a set of entries representing the data of this multiset

    • isEmpty

      public boolean isEmpty()
      Deprecated.
      Specified by:
      isEmpty in interface Collection<E>

    • clear

      public void clear()
      Deprecated.
      Specified by:
      clear in interface Collection<E>

    • contains

      public boolean contains(@Nullable Object element)
      Deprecated.
      Description copied from interface: Multiset
      Determines whether this multiset contains the specified element.

      This method refines Collection.contains(java.lang.Object) to further specify that it may not throw an exception in response to element being null or of the wrong type.

      Specified by:
      contains in interface Collection<E>
      Specified by:
      contains in interface Multiset<E>
      Overrides:
      contains in class AbstractCollection<E>
      Parameters:
      element - the element to check for
      Returns:
      true if this multiset contains at least one occurrence of the element

    • iterator

      public Iterator<E> iterator()
      Deprecated.
      Description copied from interface: Multiset

      Elements that occur multiple times in the multiset will appear multiple times in this iterator, though not necessarily sequentially.

      Specified by:
      iterator in interface Collection<E>
      Specified by:
      iterator in interface Iterable<E>
      Specified by:
      iterator in interface Multiset<E>
      Specified by:
      iterator in class AbstractCollection<E>

    • add

      public boolean add(@Nullable E element)
      Deprecated.
      Description copied from interface: Multiset
      Adds a single occurrence of the specified element to this multiset.

      This method refines Collection.add(E), which only ensures the presence of the element, to further specify that a successful call must always increment the count of the element, and the overall size of the collection, by one.

      Specified by:
      add in interface Collection<E>
      Specified by:
      add in interface Multiset<E>
      Overrides:
      add in class AbstractCollection<E>
      Parameters:
      element - the element to add one occurrence of; may be null only if explicitly allowed by the implementation
      Returns:
      true always, since this call is required to modify the multiset, unlike other Collection types

    • remove

      public boolean remove(@Nullable Object element)
      Deprecated.
      Description copied from interface: Multiset
      Removes a single occurrence of the specified element from this multiset, if present.

      This method refines Collection.remove(java.lang.Object) to further specify that it may not throw an exception in response to element being null or of the wrong type.

      Specified by:
      remove in interface Collection<E>
      Specified by:
      remove in interface Multiset<E>
      Overrides:
      remove in class AbstractCollection<E>
      Parameters:
      element - the element to remove one occurrence of
      Returns:
      true if an occurrence was found and removed

    • addAll

      public boolean addAll(Collection<? extends E> elementsToAdd)
      Deprecated.

      This implementation is highly efficient when elementsToAdd is itself a Multiset.

      Specified by:
      addAll in interface Collection<E>
      Overrides:
      addAll in class AbstractCollection<E>

    • removeAll

      public boolean removeAll(Collection<?> elementsToRemove)
      Deprecated.
      Description copied from interface: Multiset

      Note: This method ignores how often any element might appear in c, and only cares whether or not an element appears at all. If you wish to remove one occurrence in this multiset for every occurrence in c, see Multisets.removeOccurrences(Multiset, Multiset).

      This method refines Collection.removeAll(java.util.Collection<?>) to further specify that it may not throw an exception in response to any of elements being null or of the wrong type.

      Specified by:
      removeAll in interface Collection<E>
      Specified by:
      removeAll in interface Multiset<E>
      Overrides:
      removeAll in class AbstractCollection<E>

    • retainAll

      public boolean retainAll(Collection<?> elementsToRetain)
      Deprecated.
      Description copied from interface: Multiset

      Note: This method ignores how often any element might appear in c, and only cares whether or not an element appears at all. If you wish to remove one occurrence in this multiset for every occurrence in c, see Multisets.retainOccurrences(Multiset, Multiset).

      This method refines Collection.retainAll(java.util.Collection<?>) to further specify that it may not throw an exception in response to any of elements being null or of the wrong type.

      Specified by:
      retainAll in interface Collection<E>
      Specified by:
      retainAll in interface Multiset<E>
      Overrides:
      retainAll in class AbstractCollection<E>
      See Also:

    • elementSet

      public Set<E> elementSet()
      Deprecated.
      Description copied from interface: Multiset
      Returns the set of distinct elements contained in this multiset. The element set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. The order of the elements in the element set is unspecified.

      If the element set supports any removal operations, these necessarily cause all occurrences of the removed element(s) to be removed from the multiset. Implementations are not expected to support the add operations, although this is possible.

      A common use for the element set is to find the number of distinct elements in the multiset: elementSet().size().

      Specified by:
      elementSet in interface Multiset<E>
      Returns:
      a view of the set of distinct elements in this multiset

    • equals

      public boolean equals(@Nullable Object object)
      Deprecated.
      Compares the specified object with this multiset for equality. Returns true if the given object is also a multiset and contains equal elements with equal counts, regardless of order.

      This implementation returns true if object is a multiset of the same size and if, for each element, the two multisets have the same count.

      Specified by:
      equals in interface Collection<E>
      Specified by:
      equals in interface Multiset<E>
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Deprecated.
      Returns the hash code for this multiset. This is defined as the sum of 
         

   ((element == null) ? 0 : element.hashCode()) ^ count(element)

      over all distinct elements in the multiset. It follows that a multiset and its entry set always have the same hash code.

      This implementation returns the hash code of Multiset.entrySet().

      Specified by:
      hashCode in interface Collection<E>
      Specified by:
      hashCode in interface Multiset<E>
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Deprecated.

      It is recommended, though not mandatory, that this method return the result of invoking Multiset.toString() on the Multiset.entrySet(), yielding a result such as [a x 3, c, d x 2, e].

      This implementation returns the result of invoking toString on Multiset.entrySet().

      Specified by:
      toString in interface Multiset<E>
      Overrides:
      toString in class AbstractCollection<E>