org.eclipse.dirigible.commons.api.context.ThreadContextFacade Maven / Gradle / Ivy
/*
* Copyright (c) 2022 SAP SE or an SAP affiliate company and Eclipse Dirigible contributors
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v2.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v20.html
*
* SPDX-FileCopyrightText: 2022 SAP SE or an SAP affiliate company and Eclipse Dirigible contributors
* SPDX-License-Identifier: EPL-2.0
*/
package org.eclipse.dirigible.commons.api.context;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.atomic.AtomicLong;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Scripting context facade is the centralized place where the different scripting facade providers
* can register the request (sync) scoped objects.
*/
public class ThreadContextFacade {
/** The Constant logger. */
private static final Logger logger = LoggerFactory.getLogger(ThreadContextFacade.class);
/** The Constant STACKED_CONTEXT. */
private static final ThreadLocal>> STACKED_CONTEXT = new ThreadLocal<>();
/** The Constant STACKED_CLOSEABLES. */
private static final ThreadLocal>> STACKED_CLOSEABLES = new ThreadLocal<>();
/** The Constant UUID_GENERATOR. */
private static final AtomicLong UUID_GENERATOR = new AtomicLong(Long.MIN_VALUE);
/** The Constant STACK_ID. */
private static final ThreadLocal STACK_ID = new ThreadLocal<>();
/**
* Initializes the context. This has to be called at the very first (as possible) place at the service entry point
*/
public static void setUp() {
if (stackedContextIsEmpty()) {
STACKED_CONTEXT.set(new HashMap<>());
}
if (stackedCloseablesIsEmpty()) {
STACKED_CLOSEABLES.set(new HashMap<>());
}
Integer currentStackId = STACK_ID.get();
if (currentStackId == null) {
STACK_ID.set(0);
} else {
STACK_ID.set(currentStackId + 1);
}
STACKED_CONTEXT.get().put(STACK_ID.get(), collectParentObjects());
STACKED_CLOSEABLES.get().put(STACK_ID.get(), new HashMap<>());
if (logger.isTraceEnabled()) {logger.trace("Scripting context {} has been set up", Thread.currentThread().hashCode());}
}
/**
* Collect parent objects.
*
* @return the map
*/
private static Map collectParentObjects() {
Map allParentObjects = new HashMap<>();
for (int parentStackId = STACK_ID.get() - 1; parentStackId >= 0; parentStackId -= 1) {
Map parentStackObjects = STACKED_CONTEXT.get().get(parentStackId);
allParentObjects.putAll(parentStackObjects);
}
return allParentObjects;
}
/**
* IMPORTANT! This have to be added at the finally block to clean up objects after the execution of the service.
*/
public static void tearDown() {
Integer stackId = STACK_ID.get();
if (stackId == null) {
return;
}
if (stackedContextIsNotEmpty()) {
STACKED_CONTEXT.get().get(stackId).clear();
}
if (stackedCloseablesIsNotEmpty()) {
Map CLOSEABLES = STACKED_CLOSEABLES.get().get(stackId);
for (Entry closeable : CLOSEABLES.entrySet()) {
try {
if (logger.isErrorEnabled()) {logger.error("Object of type {} from the context {} has not been closed properly.", closeable.getValue().getClass().getCanonicalName(), Thread.currentThread().hashCode());}
closeable.getValue().close();
} catch (Exception e) {
if (logger.isErrorEnabled()) {logger.error(e.getMessage(), e);}
}
}
STACKED_CLOSEABLES.get().get(stackId).clear();
}
if (stackId == 0) {
STACKED_CONTEXT.remove();
STACKED_CLOSEABLES.remove();
}
STACK_ID.set(stackId - 1);
if (logger.isTraceEnabled()) {logger.trace("Scripting context {} has been torn down", Thread.currentThread().hashCode());}
}
/**
* Get a context scripting object.
*
* @param key the key
* @return the value by this key
* @throws ContextException in case of an error
*/
public static Object get(String key) throws ContextException {
checkContext();
Map> stackedContext = STACKED_CONTEXT.get();
Map currentStack = stackedContext.get(STACK_ID.get());
return currentStack.get(key);
}
/**
* Set a context scripting object.
*
* @param value the value
* @return the UUID of the object
* @throws ContextException in case of an error
*/
public static String set(Object value) throws ContextException {
final String uuid = generateObjectId();
set(uuid, value);
return uuid;
}
/**
* Set a context scripting object. If object with
* with this key exists, it will be replaced with
* the new object
*
* @param key the key
* @param value the value
* @throws ContextException in case of an error
*/
public static void set(String key, Object value) throws ContextException {
checkContext();
STACKED_CONTEXT.get().get(STACK_ID.get()).put(key, value);
if (logger.isTraceEnabled()) {logger.trace("Context object has been added to {} with key {}", Thread.currentThread().hashCode(), key);}
}
/**
* Remove a context scripting object.
*
* @param key the key
* @throws ContextException in case of an error
*/
public static void remove(String key) throws ContextException {
checkContext();
STACKED_CONTEXT.get().get(STACK_ID.get()).remove(key);
if (logger.isTraceEnabled()) {logger.trace("Context object has been removed - key {}", key);}
}
/**
* Check context.
*
* @throws ContextException the context exception
*/
private static void checkContext() throws ContextException {
if (STACKED_CONTEXT.get() == null) {
throw new ContextException("Context has not been initialized");
}
}
/**
* Check whether the facade is valid.
*
* @return yes, if it is valid
*/
public static boolean isValid() {
return (STACKED_CONTEXT.get() != null);
}
/**
* Generate object id.
*
* @return the string
*/
private static String generateObjectId() {
return Long.toString(UUID_GENERATOR.incrementAndGet(), Character.MAX_RADIX);
}
/**
* Add a closeable object to the map.
*
* @param closeable the closeable object
*/
public static void addCloseable(AutoCloseable closeable) {
if (STACKED_CLOSEABLES.get() != null) {
STACKED_CLOSEABLES.get().get(STACK_ID.get()).put(STACK_ID.get() + "_" + closeable.hashCode(), closeable);
if (logger.isTraceEnabled()) {logger.trace("Closeable object has been added to {} with hash {}", Thread.currentThread().hashCode(), closeable.hashCode());}
}
}
/**
* Remove a closeable object.
*
* @param closeable the closeable object
*/
public static void removeCloseable(AutoCloseable closeable) {
if (STACKED_CLOSEABLES.get() != null) {
STACKED_CLOSEABLES.get().get(STACK_ID.get()).remove(STACK_ID.get() + "_" + closeable.hashCode());
if (logger.isTraceEnabled()) {logger.trace("Closeable object has been removed - hash {}", closeable.hashCode());}
}
}
/**
* Stacked context is empty.
*
* @return true, if successful
*/
private static boolean stackedContextIsEmpty() {
Map> stackedContext = STACKED_CONTEXT.get();
return stackedContext == null || stackedContext.isEmpty();
}
/**
* Stacked context is not empty.
*
* @return true, if successful
*/
private static boolean stackedContextIsNotEmpty() {
Map> stackedContext = STACKED_CONTEXT.get();
return stackedContext != null && !stackedContext.isEmpty();
}
/**
* Stacked closeables is empty.
*
* @return true, if successful
*/
private static boolean stackedCloseablesIsEmpty() {
Map> stackedCloseables = STACKED_CLOSEABLES.get();
return stackedCloseables == null || stackedCloseables.isEmpty();
}
/**
* Stacked closeables is not empty.
*
* @return true, if successful
*/
private static boolean stackedCloseablesIsNotEmpty() {
Map> stackedCloseables = STACKED_CLOSEABLES.get();
return stackedCloseables != null && !stackedCloseables.isEmpty();
}
}
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