org.apache.druid.frame.channel.ReadableNilFrameChannel Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of druid-processing Show documentation
Show all versions of druid-processing Show documentation
A module that is everything required to understands Druid Segments
/*
* 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.druid.frame.channel;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import org.apache.druid.frame.Frame;
import java.util.NoSuchElementException;
/**
* Empty channel.
*/
public class ReadableNilFrameChannel implements ReadableFrameChannel
{
public static final ReadableNilFrameChannel INSTANCE = new ReadableNilFrameChannel();
private ReadableNilFrameChannel()
{
}
@Override
public boolean isFinished()
{
return true;
}
@Override
public boolean canRead()
{
return false;
}
@Override
public Frame read()
{
throw new NoSuchElementException();
}
@Override
public ListenableFuture> readabilityFuture()
{
return Futures.immediateFuture(null);
}
@Override
public void close()
{
// Nothing to do.
}
}