com.splunk.shuttl.archiver.metastore.FlatFileStorage.java Source code

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Here is the source code for com.splunk.shuttl.archiver.metastore.FlatFileStorage.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.metastore;

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

import java.io.File;
import java.io.IOException;

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

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

public class FlatFileStorage {

    private static final Logger logger = Logger.getLogger(FlatFileStorage.class);
    private LocalFileSystemPaths localFileSystemPaths;

    public FlatFileStorage(LocalFileSystemPaths localFileSystemPaths) {
        this.localFileSystemPaths = localFileSystemPaths;
    }

    /**
     * @return a {@link File} that's unique for the bucket and its filename.
     */
    public File getFlatFile(Bucket bucket, String fileName) {
        return new File(localFileSystemPaths.getMetadataDirectory(bucket), fileName);
    }

    /**
     * Writes data to a file identified by a bucket and an extension.
     */
    public void writeFlatFile(Bucket bucket, String fileName, String data) {
        File file = getFlatFile(bucket, fileName);
        writeFlatFile(file, data);
    }

    /**
     * Writes data to an existing file, that can be read by the
     * {@link FlatFileStorage} class.
     */
    void writeFlatFile(File file, String data) {
        String content = data + "";
        try {
            file.getParentFile().mkdirs();
            file.createNewFile();
            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));
    }

    /**
     * @return first line of data read from the file.
     */
    public String readFlatFile(File file) {
        try {
            return getFirstLineFromFile(file);
        } catch (Exception e) {
            throw new FlatFileReadException(e);
        }
    }

    private String getFirstLineFromFile(File file) throws IOException {
        return FileUtils.readLines(file).get(0);
    }

    public static class FlatFileReadException extends RuntimeException {

        private static final long serialVersionUID = 0L;

        public FlatFileReadException(Exception e) {
            super(e);
        }
    }
}