/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.beam.sdk.state;
import org.apache.beam.sdk.annotations.Experimental;
import org.apache.beam.sdk.annotations.Experimental.Kind;
/**
* A {@link ReadableState} cell containing a set of elements.
*
* <p>Implementations of this form of state are expected to implement set operations such as {@link
* #contains(Object)} efficiently, reading as little of the overall set as possible.
*
* @param <T> The type of elements in the set.
*/
@Experimental(Kind.STATE)
public interface SetState<T> extends GroupingState<T, Iterable<T>> {
/** Returns true if this set contains the specified element. */
ReadableState<Boolean> contains(T t);
/**
* Ensures a value is a member of the set, returning {@code true} if it was added and {@code
* false} otherwise.
*/
ReadableState<Boolean> addIfAbsent(T t);
/** Removes the specified element from this set if it is present. */
void remove(T t);
@Override
SetState<T> readLater();
}