rhelp/org.eclipse.statet.rhelp.server/src/main/java/org/eclipse/statet/internal/rhelp/server/update/REnvServiController.java

/*=============================================================================#
 # Copyright (c) 2009, 2019 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.internal.rhelp.server.update;

import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

import static org.eclipse.statet.rhelp.server.Application.BUNDLE_ID;

import java.util.NoSuchElementException;

import javax.security.auth.login.LoginException;

import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;
import org.eclipse.statet.jcommons.rmi.RMIRegistry;
import org.eclipse.statet.jcommons.rmi.RMIRegistryManager;
import org.eclipse.statet.jcommons.runtime.ClassLoaderUtils;
import org.eclipse.statet.jcommons.status.ErrorStatus;
import org.eclipse.statet.jcommons.status.ProgressMonitor;
import org.eclipse.statet.jcommons.status.StatusException;

import org.eclipse.statet.rhelp.server.Application;
import org.eclipse.statet.rj.RjException;
import org.eclipse.statet.rj.renv.core.REnv;
import org.eclipse.statet.rj.renv.core.REnvConfiguration;
import org.eclipse.statet.rj.server.util.RJContext;
import org.eclipse.statet.rj.servi.RServi;
import org.eclipse.statet.rj.servi.RServiUtils;
import org.eclipse.statet.rj.servi.node.RServiImpl;
import org.eclipse.statet.rj.servi.node.RServiNodeConfig;
import org.eclipse.statet.rj.servi.node.RServiNodeFactory;
import org.eclipse.statet.rj.servi.node.RServiNodeManager;


@NonNullByDefault
public class REnvServiController {
	
	
	private static final int LOCAL_RENV= 1;
	private static final int POOL= 3;
	
	private static class Config {
		
		private final int mode;
		private @Nullable String address;
		private @Nullable RServiNodeManager localR;
		
		public Config(final int mode) {
			this.mode= mode;
		}
		
	}
	
	private static final Config NO_CONFIG= new Config(0);
	
	
	private final REnv rEnv;
	
	private @Nullable RServiNodeConfig localConfig;
	
	private Config current= NO_CONFIG;
	
	
	public REnvServiController(final REnv rEnv) {
		this.rEnv= rEnv;
	}
	
	
	public void configure() throws StatusException {
		final REnvConfiguration rEnvConfig= this.rEnv.get(REnvConfiguration.class);
		
		final RServiNodeConfig rServiConfig= new RServiNodeConfig();
		rServiConfig.load(rEnvConfig);
		
		try {
			final Class<?> handlerClass= Class.forName("org.springframework.boot.loader.jar.Handler");
			final String url= ClassLoaderUtils.getClassLocationUrlString(handlerClass);
			rServiConfig.addToClasspath(ClassLoaderUtils.toJClassPathEntryString(url));
			rServiConfig.setJavaArgs("-Djava.protocol.handler.pkgs=org.springframework.boot.loader"); //$NON-NLS-1$
		}
		catch (final ClassNotFoundException e) {
			final String url= ClassLoaderUtils.getClassLocationUrlString(REnvServiController.class);
			if (!url.startsWith("file:")) {
				throw new StatusException(new ErrorStatus(Application.BUNDLE_ID,
						"An error occurred when configuring protocol handler for fat jar.",
						e ));
			}
		}
		
		this.localConfig= rServiConfig;
	}
	
	public void startR(final ProgressMonitor m) throws StatusException {
		startLocal(new Config(LOCAL_RENV), m);
	}
	
	public void stopR() {
		set(NO_CONFIG);
	}
	
	public void setPool(final String poolAddress) {
		final Config config= new Config(POOL);
		config.address= poolAddress;
		
		set(config);
	}
	
	private void startLocal(final Config config,
			final ProgressMonitor m) throws StatusException {
		nonNullAssert(config);
		
		final RServiNodeConfig rServiConfig= this.localConfig;
		if (rServiConfig == null) {
			throw new IllegalStateException("R is not yet configured.");
		}
		
		try {
			RJContext.class.getProtectionDomain().getCodeSource().getLocation();
			
			final RJContext context= new RJContext(RJContext.detectRJLibPaths());
//			if (System.getSecurityManager() == null) {
//				if (System.getProperty("java.security.policy") == null) {
//					final String policyFile= context.getServerPolicyFilePath();
//					System.setProperty("java.security.policy", policyFile);
//				}
//				System.setSecurityManager(new SecurityManager());
//			}
			
			final RMIRegistry registry= RMIRegistryManager.INSTANCE.getEmbeddedPrivateRegistry(m);
			
			final RServiNodeFactory nodeFactory= RServiImpl.createLocalNodeFactory(
					this.rEnv.getId(), context );
			nodeFactory.setRegistry(registry);
			nodeFactory.setConfig(rServiConfig);
			
			final RServiNodeManager localR= RServiImpl.createNodeManager(
					this.rEnv.getId(), registry, nodeFactory );
			localR.start();
			config.localR= localR;
			
			set(config);
		}
		catch (final RjException e) {
			throw new StatusException(new ErrorStatus(BUNDLE_ID,
					"Local R instance could not created.", e ));
		}
	}
	
	private void set(final Config config) {
		Config previous;
		synchronized (this) {
			previous= this.current;
			this.current= config;
		}
		
		if (previous != null && previous.localR != null) {
			previous.localR.stop();
		}
	}
	
	
	@SuppressWarnings("null")
	public RServi getRServi(final String task) throws StatusException {
		final Config config= this.current;
		final String key= this.rEnv.getId() + "->" + task;
		
		try {
			switch (config.mode) {
			case LOCAL_RENV:
				return RServiUtils.getRServi(config.localR, key);
			case POOL:
				return RServiUtils.getRServi(config.address, key);
			}
		}
		catch (final StatusException e) {
			throw new StatusException(new ErrorStatus(BUNDLE_ID,
					"R not available, please check the configuration.", e ));
		}
		catch (final LoginException e) {
			throw new StatusException(new ErrorStatus(BUNDLE_ID,
					"R not available, please check the configuration.", e ));
		}
		catch (final NoSuchElementException e) {
			throw new StatusException(new ErrorStatus(BUNDLE_ID,
					"R currently not available, please try again later.", e ));
		}
		throw new StatusException(new ErrorStatus(BUNDLE_ID,
				"R is not configured, please check the configuration." ));
	}
	
}