001    /*
002     * $Id: CachingGroovyEngine.java,v 1.5 2004/12/14 00:08:26 spullara Exp $
003     * 
004     * Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005     * 
006     * Redistribution and use of this software and associated documentation
007     * ("Software"), with or without modification, are permitted provided that the
008     * following conditions are met: 1. Redistributions of source code must retain
009     * copyright statements and notices. Redistributions must also contain a copy
010     * of this document. 2. Redistributions in binary form must reproduce the above
011     * copyright notice, this list of conditions and the following disclaimer in
012     * the documentation and/or other materials provided with the distribution. 3.
013     * The name "groovy" must not be used to endorse or promote products derived
014     * from this Software without prior written permission of The Codehaus. For
015     * written permission, please contact info@codehaus.org. 4. Products derived
016     * from this Software may not be called "groovy" nor may "groovy" appear in
017     * their names without prior written permission of The Codehaus. "groovy" is a
018     * registered trademark of The Codehaus. 5. Due credit should be given to The
019     * Codehaus - http://groovy.codehaus.org/
020     * 
021     * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
022     * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
023     * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
024     * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
025     * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
026     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
027     * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
028     * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
029     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
030     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
031     * DAMAGE.
032     *  
033     */
034    package org.codehaus.groovy.bsf;
035    
036    import groovy.lang.Binding;
037    import groovy.lang.GroovyClassLoader;
038    import groovy.lang.GroovyShell;
039    import groovy.lang.Script;
040    import org.apache.bsf.BSFDeclaredBean;
041    import org.apache.bsf.BSFException;
042    import org.apache.bsf.BSFManager;
043    import org.apache.bsf.util.BSFFunctions;
044    import org.codehaus.groovy.control.CompilerConfiguration;
045    import org.codehaus.groovy.runtime.InvokerHelper;
046    
047    import java.io.ByteArrayInputStream;
048    import java.security.AccessController;
049    import java.security.PrivilegedAction;
050    import java.util.HashMap;
051    import java.util.Map;
052    import java.util.Vector;
053    
054    /**
055     * A Caching implementation of the GroovyEngine
056     *
057     * @author James Birchfield
058     */
059    public class CachingGroovyEngine extends GroovyEngine {
060        private static final String[] EMPTY_ARGS = {
061        };
062    
063        private Map evalScripts;
064        private Map execScripts;
065        private Binding context;
066        private ClassLoader parent;
067        private GroovyClassLoader loader;
068    
069    
070        /**
071         * Evaluate an expression.
072         */
073        public Object eval(String source, int lineNo, int columnNo, Object script) throws BSFException {
074            try {
075                //          Object result = shell.evaluate(script.toString(), source);
076                Class scriptClass = (Class) evalScripts.get(script);
077                if (scriptClass == null) {
078                    scriptClass = loader.parseClass(new ByteArrayInputStream(script.toString().getBytes()), source);
079                    evalScripts.put(script, scriptClass);
080                } else {
081                    System.out.println("eval() - Using cached script...");
082                }
083                //can't cache the script because the context may be different.
084                //but don't bother loading parsing the class again
085                Script s = InvokerHelper.createScript(scriptClass, context);
086                return s.run();
087            } catch (Exception e) {
088                throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
089            }
090        }
091    
092        /**
093         * Execute a script.
094         */
095        public void exec(String source, int lineNo, int columnNo, Object script) throws BSFException {
096            try {
097                //          shell.run(script.toString(), source, EMPTY_ARGS);
098    
099                Class scriptClass = (Class) execScripts.get(script);
100                if (scriptClass == null) {
101                    scriptClass = loader.parseClass(new ByteArrayInputStream(script.toString().getBytes()), source);
102                    execScripts.put(script, scriptClass);
103                } else {
104                    System.out.println("exec() - Using cached version of class...");
105                }
106                InvokerHelper.invokeMethod(scriptClass, "main", EMPTY_ARGS);
107            } catch (Exception e) {
108                throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
109            }
110        }
111    
112        /**
113         * Initialize the engine.
114         */
115        public void initialize(final BSFManager mgr, String lang, Vector declaredBeans) throws BSFException {
116            super.initialize(mgr, lang, declaredBeans);
117            parent = mgr.getClassLoader();
118            if (parent == null)
119                parent = GroovyShell.class.getClassLoader();
120            final ClassLoader finalParent = parent;
121            this.loader =
122                    (GroovyClassLoader) AccessController.doPrivileged(new PrivilegedAction() {
123                        public Object run() {
124                            CompilerConfiguration configuration = new CompilerConfiguration();
125                            configuration.setClasspath(mgr.getClassPath());
126                            return new GroovyClassLoader(finalParent, configuration);
127                        }
128                    });
129            execScripts = new HashMap();
130            evalScripts = new HashMap();
131            context = shell.getContext();
132            // create a shell
133    
134            // register the mgr with object name "bsf"
135            context.setVariable("bsf", new BSFFunctions(mgr, this));
136    
137            int size = declaredBeans.size();
138            for (int i = 0; i < size; i++) {
139                declareBean((BSFDeclaredBean) declaredBeans.elementAt(i));
140            }
141        }
142    }