com.amazonaws.dynamodb.bootstrap.BlockingQueueWorker Maven / Gradle / Ivy

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/*
 * Copyright 2015 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Amazon Software License (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/asl/
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */
package com.amazonaws.dynamodb.bootstrap;

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.BlockingQueue;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

import com.amazonaws.services.dynamodbv2.model.AttributeValue;
import com.amazonaws.services.dynamodbv2.model.ScanResult;

/**
 * This class implements Callable, and when called iterates through it's
 * SegmentedScanResult, then pushes each item with it's size onto a blocking
 * queue.
 */
public class BlockingQueueWorker implements Callable {

    /**
     * Logger for the LogStashQueueWorker.
     */
    private static final Logger LOGGER = LogManager
            .getLogger(BlockingQueueWorker.class);

    private final BlockingQueue queue;
    private final SegmentedScanResult result;

    public BlockingQueueWorker(BlockingQueue queue,
            SegmentedScanResult result) {
        this.queue = queue;
        this.result = result;
    }

    @Override
    public Void call() {
        final ScanResult scanResult = result.getScanResult();
        final List> items = scanResult.getItems();
        final Iterator> it = items.iterator();
        boolean interrupted = false;
        try {
            do {
                try {
                    Map item = it.next();
                    DynamoDBEntryWithSize entryWithSize = new DynamoDBEntryWithSize(
                            item,
                            ItemSizeCalculator.calculateItemSizeInBytes(item));
                    queue.put(entryWithSize);
                } catch (InterruptedException e) {
                    interrupted = true;
                    LOGGER.warn("interrupted when writing item to queue: "
                            + e.getMessage());
                }
            } while (it.hasNext());
        } finally {
            if (interrupted) {
                Thread.currentThread().interrupt();
            }
        }
        return null;
    }
}