com.google.cloud.bigtable.beam.sequencefiles.ShuffledSource Maven / Gradle / Ivy
/*
* Copyright 2017 Google Inc.
*
* 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.google.cloud.bigtable.beam.sequencefiles;
import java.io.IOException;
import java.util.Collections;
import java.util.List;
import org.apache.beam.sdk.coders.Coder;
import org.apache.beam.sdk.io.BoundedSource;
import org.apache.beam.sdk.options.PipelineOptions;
import org.apache.beam.sdk.transforms.display.DisplayData.Builder;
/**
* Wrapper that will randomize the ordering of initial splits.
*
* This useful when reading sorted files to import into Bigtable. It will allow Bigtable to
* create initial split quicker.
*/
class ShuffledSource extends BoundedSource {
private final BoundedSource delegate;
/**
* Constructs the wrapper.
*
* @param delegate The actual source, whose splits to randomize
*/
ShuffledSource(BoundedSource delegate) {
this.delegate = delegate;
}
/** Shuffles the delegate source's splits. */
@Override
public List> split(
long desiredBundleSizeBytes, PipelineOptions options) throws Exception {
List> splits = delegate.split(desiredBundleSizeBytes, options);
Collections.shuffle(splits);
return splits;
}
/** {@inheritDoc} */
@Override
public long getEstimatedSizeBytes(PipelineOptions options) throws Exception {
return delegate.getEstimatedSizeBytes(options);
}
/** {@inheritDoc} */
@Override
public BoundedReader createReader(PipelineOptions options) throws IOException {
return delegate.createReader(options);
}
/** {@inheritDoc} */
@Override
public void validate() {
delegate.validate();
}
/** {@inheritDoc} */
@Override
public Coder getDefaultOutputCoder() {
return delegate.getDefaultOutputCoder();
}
/** {@inheritDoc} */
@Override
public void populateDisplayData(Builder builder) {
delegate.populateDisplayData(builder);
}
}