@GwtCompatible(emulated=true) abstract class AbstractMapBasedMultiset<E> extends AbstractMultiset<E> implements java.io.Serializable
Multiset<E>
backed by an instance of Map<E, Count>
.
For serialization to work, the subclass must specify explicit readObject
and writeObject
methods.
Modifier and Type | Class and Description |
---|---|
private class |
AbstractMapBasedMultiset.MapBasedMultisetIterator |
AbstractMultiset.ElementSet, AbstractMultiset.EntrySet
Multiset.Entry<E>
Modifier and Type | Field and Description |
---|---|
private java.util.Map<E,Count> |
backingMap |
private static long |
serialVersionUID |
private long |
size |
Modifier | Constructor and Description |
---|---|
protected |
AbstractMapBasedMultiset(java.util.Map<E,Count> backingMap)
Standard constructor.
|
Modifier and Type | Method and Description |
---|---|
int |
add(E element,
int occurrences)
Adds a number of occurrences of an element to this multiset.
|
void |
clear() |
int |
count(java.lang.Object element)
Returns the number of occurrences of an element in this multiset (the
count of the element).
|
(package private) int |
distinctElements() |
(package private) java.util.Iterator<Multiset.Entry<E>> |
entryIterator() |
java.util.Set<Multiset.Entry<E>> |
entrySet()
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. |
private static int |
getAndSet(Count i,
int count) |
java.util.Iterator<E> |
iterator() |
private void |
readObjectNoData() |
int |
remove(java.lang.Object element,
int occurrences)
Removes a number of occurrences of the specified element from this
multiset.
|
(package private) void |
setBackingMap(java.util.Map<E,Count> backingMap)
Used during deserialization only.
|
int |
setCount(E element,
int count)
Adds or removes the necessary occurrences of an element such that the
element attains the desired count.
|
int |
size() |
add, addAll, contains, createElementSet, createEntrySet, elementSet, equals, hashCode, isEmpty, remove, removeAll, retainAll, setCount, toString
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
containsAll
private transient long size
@GwtIncompatible(value="not needed in emulated source.") private static final long serialVersionUID
void setBackingMap(java.util.Map<E,Count> backingMap)
public java.util.Set<Multiset.Entry<E>> entrySet()
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.
Invoking Multiset.Entry.getCount()
on an entry in the returned
set always returns the current count of that element in the multiset, as
opposed to the count at the time the entry was retrieved.
java.util.Iterator<Multiset.Entry<E>> entryIterator()
entryIterator
in class AbstractMultiset<E>
public void clear()
clear
in interface java.util.Collection<E>
clear
in class AbstractMultiset<E>
int distinctElements()
distinctElements
in class AbstractMultiset<E>
public int size()
size
in interface java.util.Collection<E>
size
in class AbstractMultiset<E>
public java.util.Iterator<E> iterator()
Multiset
Elements that occur multiple times in the multiset will appear multiple times in this iterator, though not necessarily sequentially.
public int count(@Nullable java.lang.Object element)
Multiset
Object.equals(java.lang.Object)
-based
multiset, this gives the same result as Collections.frequency(java.util.Collection<?>, java.lang.Object)
(which would presumably perform more poorly).
Note: the utility method Iterables.frequency(java.lang.Iterable<?>, java.lang.Object)
generalizes
this operation; it correctly delegates to this method when dealing with a
multiset, but it can also accept any other iterable type.
public int add(@Nullable E element, int occurrences)
occurrences == 1
, this method has the identical effect to Multiset.add(Object)
. This method is functionally equivalent (except in the case
of overflow) to the call addAll(Collections.nCopies(element,
occurrences))
, which would presumably perform much more poorly.add
in interface Multiset<E>
add
in class AbstractMultiset<E>
element
- the element to add occurrences of; may be null only if
explicitly allowed by the implementationoccurrences
- the number of occurrences of the element to add. May be
zero, in which case no change will be made.java.lang.IllegalArgumentException
- if the call would result in more than
Integer.MAX_VALUE
occurrences of element
in this
multiset.public int remove(@Nullable java.lang.Object element, int occurrences)
Multiset
occurrences == 1
, this is functionally equivalent to the call
remove(element)
.remove
in interface Multiset<E>
remove
in class AbstractMultiset<E>
element
- the element to conditionally remove occurrences ofoccurrences
- the number of occurrences of the element to remove. May
be zero, in which case no change will be made.public int setCount(@Nullable E element, int count)
Multiset
setCount
in interface Multiset<E>
setCount
in class AbstractMultiset<E>
element
- the element to add or remove occurrences of; may be null
only if explicitly allowed by the implementationcount
- the desired count of the element in this multisetprivate static int getAndSet(Count i, int count)
@GwtIncompatible(value="java.io.ObjectStreamException") private void readObjectNoData() throws java.io.ObjectStreamException
java.io.ObjectStreamException