com.hedera.node.app.spi.state.EmptyReadableStates Maven / Gradle / Ivy
/*
* Copyright (C) 2022-2024 Hedera Hashgraph, LLC
*
* Licensed 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 com.hedera.node.app.spi.state;
import com.swirlds.state.spi.ReadableKVState;
import com.swirlds.state.spi.ReadableQueueState;
import com.swirlds.state.spi.ReadableSingletonState;
import com.swirlds.state.spi.ReadableStates;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Collections;
import java.util.Objects;
import java.util.Set;
/** An implementation of {@link ReadableStates} that is always empty. */
public final class EmptyReadableStates implements ReadableStates {
public static final ReadableStates INSTANCE = new EmptyReadableStates();
@NonNull
@Override
public ReadableKVState get(@NonNull final String stateKey) {
Objects.requireNonNull(stateKey);
throw new IllegalArgumentException("There are no k/v states");
}
@NonNull
@Override
public ReadableSingletonState getSingleton(@NonNull final String stateKey) {
Objects.requireNonNull(stateKey);
throw new IllegalArgumentException("There are no singleton states");
}
@NonNull
@Override
public ReadableQueueState getQueue(@NonNull final String stateKey) {
Objects.requireNonNull(stateKey);
throw new IllegalArgumentException("There are no queue states");
}
@Override
public boolean contains(@NonNull final String stateKey) {
return false;
}
@NonNull
@Override
public Set stateKeys() {
return Collections.emptySet();
}
}