com.splunk.shuttl.archiver.bucketsize.BucketSizeIO.java Source code

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Here is the source code for com.splunk.shuttl.archiver.bucketsize.BucketSizeIO.java

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// Copyright (C) 2011 Splunk Inc.
//
// Splunk Inc. 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 com.splunk.shuttl.archiver.bucketsize;

import static com.splunk.shuttl.archiver.LogFormatter.*;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.log4j.Logger;

import com.splunk.shuttl.archiver.LocalFileSystemPaths;
import com.splunk.shuttl.archiver.filesystem.ArchiveFileSystem;
import com.splunk.shuttl.archiver.model.Bucket;

/**
 * Logic for reading and writing a file with bucket size.
 */
public class BucketSizeIO {

    private static final Logger logger = Logger.getLogger(BucketSizeIO.class);
    private final ArchiveFileSystem archiveFileSystem;
    private LocalFileSystemPaths localFileSystemPaths;

    /**
     * @param archiveFileSystem
     *          to read the file size off of.
     * @param localFileSystemPaths
     *          for storing bucket size on local disk.
     */
    public BucketSizeIO(ArchiveFileSystem archiveFileSystem, LocalFileSystemPaths localFileSystemPaths) {
        this.archiveFileSystem = archiveFileSystem;
        this.localFileSystemPaths = localFileSystemPaths;
    }

    /**
     * @return a file that contains information about the specified bucket's size.
     */
    public File getFileWithBucketSize(Bucket bucket) {
        File tempFile = getTempFileForBucket(bucket);
        writeSizeToFile(bucket.getSize(), tempFile);
        return tempFile;
    }

    private File getTempFileForBucket(Bucket bucket) {
        try {
            return createFile(bucket);
        } catch (IOException e) {
            logIOExceptionForCreatingFile(bucket, e);
            throw new RuntimeException(e);
        }
    }

    private File createFile(Bucket bucket) throws IOException {
        File file = new File(localFileSystemPaths.getMetadataDirectory(), bucket.getName() + ".size");
        file.createNewFile();
        return file;
    }

    private void logIOExceptionForCreatingFile(Bucket bucket, IOException e) {
        logger.debug(did("Tried creating temp file for BucketSizeFile.", e, "To create temp file.", "bucket",
                bucket, "exception", e));
    }

    private void writeSizeToFile(Long size, File file) {
        String content = size + "";
        try {
            FileUtils.write(file, content);
        } catch (IOException e) {
            logIOExceptionForWritingToFile(file, content, e);
            throw new RuntimeException(e);
        }
    }

    private void logIOExceptionForWritingToFile(File file, String content, IOException e) {
        logger.debug(did("Tried to write to file for BucketSizeFile.", e, "To write size to file", "file", file,
                "content", content));
    }

    /**
     * @param uriToFileWithBucketSize
     * @return
     */
    public long readSizeFromRemoteFile(URI uriToFileWithBucketSize) {
        InputStream inputStream = getInputStreamToFile(uriToFileWithBucketSize);
        List<String> lines = getLinesFromInputStream(inputStream);
        return Long.parseLong(lines.get(0));
    }

    private InputStream getInputStreamToFile(URI uriToFileWithBucketSize) {
        try {
            return archiveFileSystem.openFile(uriToFileWithBucketSize);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private List<String> getLinesFromInputStream(InputStream inputStream) {
        try {
            return IOUtils.readLines(inputStream);
        } catch (IOException e) {
            throw new RuntimeException(e); // TODO: Test this, so it's documented that
                                           // this is expected
                                           // behaviour.
        }
    }

}