| /* |
| * 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.flink.types; |
| |
| import org.apache.flink.annotation.Public; |
| import org.apache.flink.core.memory.DataInputView; |
| import org.apache.flink.core.memory.DataOutputView; |
| import org.apache.flink.core.memory.MemorySegment; |
| |
| import java.io.IOException; |
| |
| /** Null base type for programs that implements the Key interface. */ |
| @Public |
| public final class NullValue implements NormalizableKey<NullValue>, CopyableValue<NullValue> { |
| private static final long serialVersionUID = 1L; |
| |
| /** The singleton NullValue instance. */ |
| private static final NullValue INSTANCE = new NullValue(); |
| |
| /** |
| * Returns the NullValue singleton instance. |
| * |
| * @return The NullValue singleton instance. |
| */ |
| public static NullValue getInstance() { |
| return INSTANCE; |
| } |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| /** Creates a NullValue object. */ |
| public NullValue() {} |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| @Override |
| public String toString() { |
| return "(null)"; |
| } |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| @Override |
| public void read(DataInputView in) throws IOException { |
| in.readBoolean(); |
| } |
| |
| @Override |
| public void write(DataOutputView out) throws IOException { |
| out.writeBoolean(false); |
| } |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| @Override |
| public int compareTo(NullValue o) { |
| return 0; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| return (o != null && o.getClass() == NullValue.class); |
| } |
| |
| @Override |
| public int hashCode() { |
| return 53; |
| } |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| @Override |
| public int getMaxNormalizedKeyLen() { |
| return 0; |
| } |
| |
| @Override |
| public void copyNormalizedKey(MemorySegment target, int offset, int len) { |
| for (int i = offset; i < offset + len; i++) { |
| target.put(i, (byte) 0); |
| } |
| } |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| @Override |
| public int getBinaryLength() { |
| return 1; |
| } |
| |
| @Override |
| public void copyTo(NullValue target) {} |
| |
| @Override |
| public NullValue copy() { |
| return NullValue.getInstance(); |
| } |
| |
| @Override |
| public void copy(DataInputView source, DataOutputView target) throws IOException { |
| source.readBoolean(); |
| target.writeBoolean(false); |
| } |
| } |