/*
* R : A Computer Language for Statistical Data Analysis
* Copyright (C) 1995, 1996 Robert Gentleman and Ross Ihaka
* Copyright (C) 1997--2008 The R Development Core Team
* Copyright (C) 2003, 2004 The R Foundation
* Copyright (C) 2010 bedatadriven
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.renjin.appengine;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.script.ScriptEngine;
import javax.servlet.ServletContext;
import org.apache.commons.vfs2.CacheStrategy;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemManager;
import org.apache.commons.vfs2.cache.NullFilesCache;
import org.apache.commons.vfs2.impl.DefaultFileSystemManager;
import org.apache.commons.vfs2.provider.LocalFileProvider;
import org.apache.commons.vfs2.provider.url.UrlFileProvider;
import org.renjin.eval.Session;
import org.renjin.eval.SessionBuilder;
import org.renjin.eval.vfs.FastJarFileProvider;
import org.renjin.script.RenjinScriptEngineFactory;
import com.google.common.annotations.VisibleForTesting;
//import r.scripting.RenjinScriptEngineFactory;
public class AppEngineContextFactory {
private static final Logger LOG = Logger.getLogger(AppEngineContextFactory.class.getName() );
public static ScriptEngine createScriptEngine(ServletContext servletContext) {
RenjinScriptEngineFactory factory = new RenjinScriptEngineFactory();
return factory.getScriptEngine(createSession(servletContext));
}
public static Session createSession(ServletContext servletContext) {
FileSystemManager fileSystemManager;
try {
fileSystemManager = createFileSystemManager(servletContext);
} catch (FileSystemException e) {
LOG.log(Level.SEVERE, "Failed to initialize VFS file system manager", e);
throw new RuntimeException(e);
}
try {
// initialize our master context here; a fresh but shallow copy will
// be forked on each incoming request
Session session = new SessionBuilder()
.withFileSystemManager(fileSystemManager)
.withDefaultPackages()
.build();
session.setWorkingDirectory(fileSystemManager.resolveFile("file:///"));
return session;
} catch (IOException e) {
LOG.log(Level.SEVERE, "Failed to initialize master context", e);
throw new RuntimeException(e);
}
}
public static FileSystemManager createFileSystemManager(ServletContext context) throws FileSystemException {
final File contextRoot = contextRoot(context);
return createFileSystemManager(new AppEngineLocalFilesSystemProvider(contextRoot));
}
private static File contextRoot(ServletContext context) {
return new File(context.getRealPath(context.getContextPath()));
}
@VisibleForTesting
static FileSystemManager createFileSystemManager(LocalFileProvider localFileProvider) throws FileSystemException {
try {
FastJarFileProvider jarFileProvider = new FastJarFileProvider();
// this provides a fake local file system rooted in the servlet context root.
// this is necessary because on the actual appengine platform, any queries to the ancestors
// of the servlet context (e.g. /base) will throw a security exception
DefaultFileSystemManager dfsm = new DefaultFileSystemManager();
dfsm.addProvider("jar", jarFileProvider);
dfsm.addProvider("file", localFileProvider);
dfsm.addExtensionMap("jar", "jar");
dfsm.setDefaultProvider(new UrlFileProvider());
dfsm.setFilesCache(new NullFilesCache());
dfsm.setCacheStrategy(CacheStrategy.ON_RESOLVE);
dfsm.setBaseFile(new File("/"));
dfsm.init();
return dfsm;
} catch(FileSystemException e) {
LOG.log(Level.SEVERE, "Failed to initialize file system for development server", e);
throw new RuntimeException(e);
}
}
@VisibleForTesting
static String findHomeDirectory(File servletContextRoot, String sexpClassPath) throws IOException {
LOG.fine("Found SEXP in '" + sexpClassPath);
File jarFile = jarFileFromResource(sexpClassPath);
StringBuilder homePath = new StringBuilder();
homePath.append('/').append(jarFile.getName()).append("!/org/renjin");
File parent = jarFile.getParentFile();
while(!servletContextRoot.equals(parent)) {
if(parent==null) {
throw new IllegalStateException("Expected the renjin-core jar to be in the WEB-INF, bound found it in:\n" +
jarFile.toString() + "\nAre you sure you are running in a servlet environment?");
}
homePath.insert(0, parent.getName());
homePath.insert(0, '/');
parent = parent.getParentFile();
}
homePath.insert(0, "jar:file://");
return homePath.toString();
}
@VisibleForTesting
static File jarFileFromResource(String path) {
int sep = path.indexOf('!');
if(sep == -1) {
throw new IllegalStateException("Expected to find renjin-core classes in a jar in the WEB-INF/lib folder." +
" This probably means that you are not running in a servlet environment and you do not need to use " +
" AppEngineContextFactory; you may be able to just call Context.newTopLevelContext()");
}
String jarPath = path.substring(0,sep);
if(jarPath.toLowerCase().startsWith("file:")) {
jarPath = jarPath.substring(5);
}
return new File(jarPath);
}
}