com.asakusafw.lang.compiler.mapreduce.testing.InputFormatTester.java Source code

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/**
 * Copyright 2011-2017 Asakusa Framework Team.
 *
 * 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.asakusafw.lang.compiler.mapreduce.testing;

import java.io.IOException;
import java.util.List;
import java.util.function.Consumer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import org.apache.hadoop.mapreduce.task.TaskAttemptContextImpl;
import org.apache.hadoop.util.ReflectionUtils;

import com.asakusafw.runtime.io.util.DataBuffer;
import com.asakusafw.runtime.windows.WindowsConfigurator;

/**
 * Testing utilities for {@link InputFormat}.
 */
public class InputFormatTester {

    static {
        WindowsConfigurator.install();
    }

    private final InputFormat<?, ?> format;

    private final Configuration conf;

    /**
     * Creates a new instance.
     * @param conf the current configuration
     * @param format the target format object
     */
    public InputFormatTester(Configuration conf, InputFormat<?, ?> format) {
        this.conf = conf;
        this.format = format;
    }

    /**
     * Creates a new instance.
     * @param conf the current configuration
     * @param format the target format class
     */
    public InputFormatTester(Configuration conf, Class<?> format) {
        this.conf = conf;
        this.format = (InputFormat<?, ?>) ReflectionUtils.newInstance(format, conf);
    }

    /**
     * Collects input contents.
     * @param <T> the data type
     * @param collector the target collector
     * @throws IOException if failed
     * @throws InterruptedException if interrupted
     */
    @SuppressWarnings("unchecked")
    public <T> void collect(Consumer<T> collector) throws IOException, InterruptedException {
        TaskAttemptContext context = new TaskAttemptContextImpl(conf, new TaskAttemptID());
        List<InputSplit> splits = format.getSplits(context);
        for (InputSplit split : splits) {
            InputSplit restored = restore(split);
            try (RecordReader<?, ?> reader = format.createRecordReader(restored, context)) {
                reader.initialize(restored, context);
                while (reader.nextKeyValue()) {
                    collector.accept((T) reader.getCurrentValue());
                }
            }
        }
    }

    private InputSplit restore(InputSplit split) throws IOException {
        if (split instanceof Writable) {
            DataBuffer buffer = new DataBuffer();
            ((Writable) split).write(buffer);
            ((Writable) split).readFields(buffer);
        }
        return split;
    }

    /**
     * Collects values from {@code InputFormat}.
     * @param <T> the value type
     * @deprecated Use {@link Consumer} instead
     */
    @Deprecated
    public interface Collector<T> extends Consumer<T> {

        /**
         * Handles an object.
         * @param object the target
         */
        void handle(T object);

        @Override
        default void accept(T t) {
            handle(t);
        }
    }
}