ContentDAO.java

package eu.europeana.cloud.service.mcs.persistent.swift;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import eu.europeana.cloud.service.mcs.exception.FileAlreadyExistsException;
import eu.europeana.cloud.service.mcs.exception.FileNotExistsException;

/**
 * Content storage DAOs interface .
 */
public interface ContentDAO {

    /**
     * Copies content of one storage object to another.
     * 
     * @param sourceObjectId
     *            name of the source storage object
     * @param trgObjectId
     *            name of the target storage object
     * @throws FileNotExistsException
     *             if source object does not exist in the storage
     */
    void copyContent(String sourceObjectId, String trgObjectId)
            throws FileNotExistsException, FileAlreadyExistsException, IOException;


    /**
     * Deletes storage object identified by fileName.
     * 
     * @param fileName
     *            name of the object to be deleted
     * @throws FileNotExistsException
     *             if object does not exist in the storage
     */
    void deleteContent(String fileName)
            throws FileNotExistsException;


    /**
     * Retrieves content of file from storage. Can retrieve range of bytes of
     * the file.
     * 
     * @param fileName
     *            name of the file to retrieve
     * @param start
     *            first offset included in the response. If equal to -1,
     *            ignored.
     * @param end
     *            last offset included in the response (inclusive). If equal to
     *            -1, ignored.
     * @param os
     *            outputstream the content is written to
     * @throws IOException
     *             if an I/O error occurs
     * @throws FileNotExistsException
     *             if object does not exist in the storage
     */
    void getContent(String fileName, long start, long end, OutputStream os)
            throws IOException, FileNotExistsException;


    /**
     * Puts given content to storage under given fileName. Counts and returns
     * content length and md5 checksum from given data.
     * 
     * @param fileName
     *            name of the file
     * @param data
     *            content of file to be saved
     * @return md5 and content length
     * @throws IOException
     *             if an I/O error occurs
     */
    PutResult putContent(String fileName, InputStream data)
            throws IOException;

}