Object readResolve() {
LinkedHashMultiset<Object> multiset = LinkedHashMultiset.create(elements.length);
for (int i = 0; i < elements.length; i++) {
multiset.add(elements[i], counts[i]);
}
return ImmutableMultiset.copyOf(multiset);
}
/**
* Returns an immutable multiset containing the given elements.
*
* <p>The multiset is ordered by the first occurrence of each element. For example, {@code
* ImmutableMultiset.copyOf(Arrays.asList(2, 3, 1, 3))} yields a multiset with elements in the
* order {@code 2, 3, 3, 1}.
*
* <p>Despite the method name, this method attempts to avoid actually copying the data when it is
* safe to do so. The exact circumstances under which a copy will or will not be performed are
* undocumented and subject to change.
*
* <p><b>Note:</b> Despite what the method name suggests, if {@code elements} is an {@code
* ImmutableMultiset}, no copy will actually be performed, and the given multiset itself will be
* returned.
*
* @throws NullPointerException if any of {@code elements} is null
*/
public static <E> ImmutableMultiset<E> copyOf(Iterable<? extends E> elements) {
if (elements instanceof ImmutableMultiset) {
@SuppressWarnings("unchecked") // all supported methods are covariant
ImmutableMultiset<E> result = (ImmutableMultiset<E>) elements;
if (!result.isPartialView()) {
return result;
}
}
Multiset<? extends E> multiset =
(elements instanceof Multiset)
? Multisets.cast(elements)
: LinkedHashMultiset.create(elements);
return copyOfInternal(multiset);
}
public void testBuilderAddAllHandlesNullsCorrectly() {
ImmutableMultiset.Builder<String> builder = ImmutableMultiset.builder();
try {
builder.addAll((Collection<String>) null);
fail("expected NullPointerException");
} catch (NullPointerException expected) {
}
builder = ImmutableMultiset.builder();
List<String> listWithNulls = asList("a", null, "b");
try {
builder.addAll(listWithNulls);
fail("expected NullPointerException");
} catch (NullPointerException expected) {
}
builder = ImmutableMultiset.builder();
Multiset<String> multisetWithNull = LinkedHashMultiset.create(asList("a", null, "b"));
try {
builder.addAll(multisetWithNull);
fail("expected NullPointerException");
} catch (NullPointerException expected) {
}
}
@BeforeExperiment
void setUp() {
hashMultiset = HashMultiset.create(size);
linkedHashMultiset = LinkedHashMultiset.create(size);
treeMultiset = TreeMultiset.create();
Random random = new Random();
int sizeRemaining = size;
// TODO(kevinb): generate better test contents for multisets
for (int i = 0; sizeRemaining > 0; i++) {
// The JVM will return interned values for small ints.
Integer value = random.nextInt(1000) + 128;
int count = Math.min(random.nextInt(10) + 1, sizeRemaining);
sizeRemaining -= count;
hashMultiset.add(value, count);
linkedHashMultiset.add(value, count);
treeMultiset.add(value, count);
}
// TODO(kevinb): convert to assert once benchmark tests enable asserts by default
Preconditions.checkState(hashMultiset.size() == size);
}
/**
* Creates a new builder. The returned builder is equivalent to the builder generated by {@link
* ImmutableMultiset#builder}.
*/
public Builder() {
this(LinkedHashMultiset.<E>create());
}
/**
* Returns an immutable multiset containing the given elements.
*
* <p>The multiset is ordered by the first occurrence of each element. For example, {@code
* ImmutableMultiset.copyOf(Arrays.asList(2, 3, 1, 3).iterator())} yields a multiset with elements
* in the order {@code 2, 3, 3, 1}.
*
* @throws NullPointerException if any of {@code elements} is null
*/
public static <E> ImmutableMultiset<E> copyOf(Iterator<? extends E> elements) {
Multiset<E> multiset = LinkedHashMultiset.create();
Iterators.addAll(multiset, elements);
return copyOfInternal(multiset);
}