/*
* Copyright 2012-2014 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (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/apache2.0
*
* or in the "license" file accompanying this file. This file 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.amazonaws.services.simpleworkflow.flow.examples.splitmerge;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.ObjectMetadata;
import com.amazonaws.services.s3.model.S3Object;
public class AverageCalculatorActivitiesImpl implements AverageCalculatorActivities {
private static final int ROW_SIZE = 7;
private final AmazonS3 storage;
public AverageCalculatorActivitiesImpl(AmazonS3 storage) {
this.storage = storage;
}
@Override
public int computeDataSizeForInputData(String bucketName, String filename) {
ObjectMetadata metadata = storage.getObjectMetadata(bucketName, filename);
long size = metadata.getContentLength();
return (int) size / ROW_SIZE;
}
@Override
public int computeSumForChunk(String bucketName, String filename, int chunkNumber, int chunkSize) throws IOException {
int sum = 0;
int from = chunkNumber * chunkSize;
int to = from + chunkSize;
int offset = chunkNumber * chunkSize * ROW_SIZE;
int bytesToRead = chunkSize * ROW_SIZE;
// Create a request to download content for computing the sum for this chunk
GetObjectRequest getRequest = new GetObjectRequest(bucketName, filename);
getRequest.setRange(offset, offset + bytesToRead - 1);
// Download content
S3Object obj = storage.getObject(getRequest);
InputStream inputStream = obj.getObjectContent();
InputStreamReader inputStreamReader = null;
BufferedReader reader = null;
try {
String line = null;
inputStreamReader = new InputStreamReader(inputStream);
reader = new BufferedReader(inputStreamReader);
// Compute sum for downloaded content
while ((line = reader.readLine()) != null) {
sum += Integer.parseInt(line);
}
}
finally {
if (reader != null)
reader.close();
if (inputStreamReader != null)
inputStreamReader.close();
if (inputStream != null)
inputStream.close();
}
System.out.printf("Sum from '%d' to '%d' is: '%d'\n", from + 1, to, sum);
return sum;
}
@Override
public void reportResult(double average) {
System.out.printf("Average is: %6.2f.\n", average);
}
}