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/*-
* ============LICENSE_START=======================================================
* ONAP : APPC
* ================================================================================
* Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
* ================================================================================
* Copyright (C) 2017 Amdocs
* =============================================================================
* 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.
*
* ============LICENSE_END=========================================================
*/
package org.onap.appc.client.impl.core;
import org.onap.appc.client.impl.protocol.*;
import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Consolidates all services(Registry, Timeout and Task Queue) for handling of requests/responses events.
*/
class CoreManager{
private final EELFLogger LOG = EELFManager.getInstance().getLogger(CoreManager.class);
private final ProtocolFactory protocolFactory;
protected AsyncProtocol protocol;
private final RetrieveMessageCallback protocolCallback = null;
private final CoreRegistry registry;
private final ITimerService timerService;
private final TaskQueueManager queueManager;
private String DEFAULT_TIMEOUT = "300000";
private final static String RESPONSE_TIMEOUT = "client.response.timeout";
private final static String GRACEFUL_SHUTDOWN_TIMEOUT = "client.graceful.shutdown.timeout";
private boolean isForceShutdown = false;
private AtomicBoolean isGracefulShutdown = new AtomicBoolean(false);
private long shutdownTimeout;
CoreManager(Properties prop) throws CoreException {
protocolFactory = ProtocolFactory.getInstance();
try {
initProtocol(prop);
}catch (ProtocolException e){
throw new CoreException(e);
}
registry = new CoreRegistry<RequestResponseHandler>(new EmptyRegistryCallbackImpl());
String timeoutProp = prop.getProperty(RESPONSE_TIMEOUT, DEFAULT_TIMEOUT);
long responseTimeout = Long.parseLong(timeoutProp);
String gracefulTimeout = prop.getProperty(GRACEFUL_SHUTDOWN_TIMEOUT, DEFAULT_TIMEOUT);
shutdownTimeout = Long.parseLong(gracefulTimeout);
timerService = new TimerServiceImpl(responseTimeout);
queueManager = new TaskQueueManager(prop);
listenShutdown();
}
/**
* initiates protocol layer services.
* @param prop - Properties
*/
private void initProtocol(Properties prop) throws ProtocolException {
protocol = (AsyncProtocol) protocolFactory.getProtocolObject(ProtocolType.ASYNC);
protocol.init(prop, getProtocolCallback());
}
/**
* Creates protocol response callback
* @return - @{@link ProtocolResponseCallbackImpl}
*/
RetrieveMessageCallback getProtocolCallback(){
return new ProtocolResponseCallbackImpl();
}
/**
* Registers a new handler in registry
* @param corrID - Correlation ID
* @param requestResponseHandler handler to be called when response arrives
*/
void registerHandler(String corrID, RequestResponseHandler requestResponseHandler){
registry.register(corrID, requestResponseHandler);
}
/**
* Remove a handler from registry service by correlation ID.
* @param corrID - Correlation ID
* @return - @{@link RequestResponseHandler}
*/
RequestResponseHandler unregisterHandler(String corrID){
return (RequestResponseHandler) registry.unregister(corrID);
}
/**
* Checks in registry service if a handler is existing.
* @param corrID - Correlation ID
* @return - boolean
*/
boolean isExistHandler(String corrID) {
return registry.isExist(corrID);
}
/**
* Starts timer for timeout event when a request was send successfully.
* @param corrID - Correlation ID
*/
void startTimer(String corrID){
timerService.add(corrID, new TimeoutHandlerImpl(corrID));
}
/**
* Cancels timer for fimeout event, in case when complete response was received
* @param corrID
*/
void cancelTimer(String corrID){
timerService.cancel(corrID);
}
/**
* Submits a new task to Queue manager. it is using for both response and timeout tasks
* @param corrID - Correlation ID
* @param task - @{@link Runnable} task.
* @throws InterruptedException
*/
void submitTask(String corrID, Runnable task) throws InterruptedException {
queueManager.submit(corrID, task);
}
/**
* Sends request to protocol.
* @param request - Request
* @param corrId - Correlation ID
* @param rpcName - RPC name
* @throws CoreException - @{@link CoreException}
*/
void sendRequest(String request, String corrId, String rpcName) throws CoreException {
MessageContext ctx = getMessageContext(corrId, rpcName);
try {
protocol.sendRequest(request, ctx);
} catch (ProtocolException e) {
unregisterHandler(corrId);
throw new CoreException(e);
}
}
/**
* Creates @{@link MessageContext}
* @param correlationId - Correlation ID
* @param rpcName - RPC Name
* @return - @{@link MessageContext}
*/
private MessageContext getMessageContext(String correlationId, String rpcName){
MessageContext msgCtx = new MessageContext();
msgCtx.setCorrelationID(correlationId);
msgCtx.setRpc(rpcName);
return msgCtx;
}
/**
* Implements response callback from protocol and filters responses by correlation ID.
* Only registered events(by correlation ID) will be handled.
*/
private class ProtocolResponseCallbackImpl implements RetrieveMessageCallback {
@Override
public void onResponse(String response, MessageContext context) {
String corrID = context.getCorrelationID();
if (corrID != null) {
RequestResponseHandler messageHandler = (RequestResponseHandler) registry.get(corrID);
if (messageHandler != null) {
LOG.info("On response callback corrID <" + corrID + "> handler " + messageHandler + " response " + response);
messageHandler.handleResponse(context, response);
}
}
}
}
/**
* listens to @{@link Runtime} shutdown event
*/
private void listenShutdown() {
Runtime.getRuntime().addShutdownHook(new Thread(){
public void run(){
gracefulShutdown();
}
});
}
/**
* Implements shutdown for client library.
* @param isForceShutdown - true force shutdown, false graceful shutdown
*/
void shutdown(boolean isForceShutdown){
if(isForceShutdown){
forceShutdown();
}else{
gracefulShutdown();
}
}
/**
* Graceful shutdown. in case of all requests already were handled, calls to force shutdown. another goes to force
* shutdown only when either all request will be handled or graceful shutdown will be time out.
*/
synchronized void gracefulShutdown(){
isGracefulShutdown.set(true);
if(registry.isEmpty()){
forceShutdown();
}
else{
try {
LOG.info("Core manager::graceful shutdown is starting... this <" + this + ">");
wait(shutdownTimeout);
LOG.info("Core manager::graceful shutdown is continue... this <" + this + ">");
forceShutdown();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
/**
* Closes Protocol, stops Queue Manager and shutdowns Time Service.
*/
private void forceShutdown(){
isForceShutdown = true;
try {
LOG.info("Starting shutdown process.");
protocol.shutdown();
queueManager.stopQueueManager();
timerService.shutdown();
} catch (InterruptedException e) {
LOG.info("Client library shutdown in progress ", e);
}
}
/**
*
* @return - true when shutdown is in process
*/
boolean isShutdownInProgress(){
return isForceShutdown || isGracefulShutdown.get();
}
/**
* Timeout handler implementation.
* This handler is responsible to assign a task for handling of timeout events.
*
*/
private class TimeoutHandlerImpl implements ITimeoutHandler {
private final String corrID;
TimeoutHandlerImpl(String corrID) {
this.corrID = corrID;
}
/**
* When a timeout event is occurring, the new Timeout task will be assigned into a queue,
* this queue is shared between both timeout and handlers which belong to same correlation ID.
*/
@Override
public void onTimeout() {
try {
submitTask(corrID, new Runnable() {
@Override
public void run() {
RequestResponseHandler requestResponseHandler = unregisterHandler(corrID);
if (requestResponseHandler != null) {
requestResponseHandler.onTimeOut();
}
}
});
} catch (InterruptedException e) {
LOG.warn("could not submit timeout task for correlation ID <" + corrID + "> ", e);
}
}
}
/**
* Wakes Up graceful shutdown.
*/
class EmptyRegistryCallbackImpl implements CoreRegistry.EmptyRegistryCallback {
@Override
public synchronized void emptyCallback() {
LOG.info("Registry is empty, wake up the shutdown!, isGraceful flag <" + isGracefulShutdown + ">");
if(isGracefulShutdown.get()){
wakeUpShutdown();
}
}
}
/**
* wakes up waiting shutdown.
*/
private synchronized void wakeUpShutdown(){
notifyAll();
}
}
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