services/provisioning-service/src/main/java/com/epam/dlab/backendapi/core/response/folderlistener/FolderListenerExecutor.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.epam.dlab.backendapi.core.response.folderlistener;

import com.epam.dlab.backendapi.ProvisioningServiceApplicationConfiguration;
import com.epam.dlab.backendapi.core.FileHandlerCallback;
import com.epam.dlab.backendapi.core.response.handlers.dao.CallbackHandlerDao;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import io.dropwizard.util.Duration;

import static com.epam.dlab.backendapi.core.response.folderlistener.FolderListener.listen;

/**
 * Starts asynchronously of waiting for file creation and processing this file.
 */
@Singleton
public class FolderListenerExecutor {
	@Inject
	private ProvisioningServiceApplicationConfiguration configuration;
	@Inject
	private CallbackHandlerDao handlerDao;

	/**
	 * Starts asynchronously of waiting for file creation and processes this file if the timeout
	 * has not expired. If timeout has been expired then writes warning message to log file and
	 * finishes waiting. This method is <b>non-blocking</b>.
	 *
	 * @param directory           name of directory for waiting for the file creation.
	 * @param timeout             timeout for waiting.
	 * @param fileHandlerCallback handler for the file processing.
	 */
	public void start(String directory, Duration timeout, FileHandlerCallback fileHandlerCallback) {
		CallbackHandlerDao dao = configuration.isHandlersPersistenceEnabled() ? handlerDao : null;
		listen(directory, fileHandlerCallback, timeout.toMilliseconds(),
				configuration.getFileLengthCheckDelay().toMilliseconds(), dao);
	}
}