/*
* Copyright 2017 LinkedIn Corp.
*
* Licensed 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 azkaban.spi;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
/**
* The Azkaban Storage interface would facilitate getting and putting objects into a storage mechanism of choice.
* By default, this is set to the MySQL database. However, users can have the ability to choose between multiple
* storage types in future.
*
* This is different from storing Azkaban state in MySQL which would typically be maintained in a different database.
*
* Note: This is a synchronous interface.
*/
public interface Storage {
/**
* Get an InputStream object by providing a key.
*
* @param key The key is a string pointing to the blob in Storage.
* @return InputStream for fetching the blob. null if the key is not found.
*
*/
InputStream get(String key) throws IOException;
/**
* Put an object and return a key.
*
* @param metadata Metadata related to the input stream
* @param localFile Read data from a local file
*
* @return Key associated with the current object on successful put
*/
String put(StorageMetadata metadata, File localFile);
/**
* Delete an object from Storage.
*
* @param key The key is a string pointing to the blob in Storage.
* @return true if delete was successful. false if there was nothing to delete.
*/
boolean delete(String key);
}