private static <K, V> ImmutableSetMultimap<K, V> copyOf( Multimap<? extends K, ? extends V> multimap, Comparator<? super V> valueComparator) { Preconditions.checkNotNull(multimap); // eager for GWT if (multimap.isEmpty() && valueComparator == null) { return of(); } if (multimap instanceof ImmutableSetMultimap) { @SuppressWarnings("unchecked") // safe since multimap is not writable ImmutableSetMultimap<K, V> kvMultimap = (ImmutableSetMultimap<K, V>) multimap; if (!kvMultimap.isPartialView()) { return kvMultimap; } } ImmutableMap.Builder<K, ImmutableSet<V>> builder = ImmutableMap.builder(); int size = 0; for (Map.Entry<? extends K, ? extends Collection<? extends V>> entry : multimap.asMap().entrySet()) { K key = entry.getKey(); Collection<? extends V> values = entry.getValue(); ImmutableSet<V> set = (valueComparator == null) ? ImmutableSet.copyOf(values) : ImmutableSortedSet.copyOf(valueComparator, values); if (!set.isEmpty()) { builder.put(key, set); size += set.size(); } } return new ImmutableSetMultimap<K, V>(builder.build(), size, valueComparator); }
@GwtIncompatible("java.io.ObjectInputStream") private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException { stream.defaultReadObject(); int keyCount = stream.readInt(); if (keyCount < 0) { throw new InvalidObjectException("Invalid key count " + keyCount); } ImmutableMap.Builder<Object, ImmutableSet<Object>> builder = ImmutableMap.builder(); int tmpSize = 0; for (int i = 0; i < keyCount; i++) { Object key = stream.readObject(); int valueCount = stream.readInt(); if (valueCount <= 0) { throw new InvalidObjectException("Invalid value count " + valueCount); } Object[] array = new Object[valueCount]; for (int j = 0; j < valueCount; j++) { array[j] = stream.readObject(); } ImmutableSet<Object> valueSet = ImmutableSet.copyOf(array); if (valueSet.size() != array.length) { throw new InvalidObjectException("Duplicate key-value pairs exist for key " + key); } builder.put(key, valueSet); tmpSize += valueCount; } ImmutableMap<Object, ImmutableSet<Object>> tmpMap; try { tmpMap = builder.build(); } catch (IllegalArgumentException e) { throw (InvalidObjectException) new InvalidObjectException(e.getMessage()).initCause(e); } FieldSettersHolder.MAP_FIELD_SETTER.set(this, tmpMap); FieldSettersHolder.SIZE_FIELD_SETTER.set(this, tmpSize); }