001    /*
002     * $Id: CachingGroovyEngine.java,v 1.6 2005/08/20 19:02:15 blackdrag 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 Object[] EMPTY_ARGS = new Object[]{new String[]{}};
061    
062        private Map evalScripts;
063        private Map execScripts;
064        private Binding context;
065        private ClassLoader parent;
066        private GroovyClassLoader loader;
067    
068    
069        /**
070         * Evaluate an expression.
071         */
072        public Object eval(String source, int lineNo, int columnNo, Object script) throws BSFException {
073            try {
074                //          Object result = shell.evaluate(script.toString(), source);
075                Class scriptClass = (Class) evalScripts.get(script);
076                if (scriptClass == null) {
077                    scriptClass = loader.parseClass(new ByteArrayInputStream(script.toString().getBytes()), source);
078                    evalScripts.put(script, scriptClass);
079                } else {
080                    System.out.println("eval() - Using cached script...");
081                }
082                //can't cache the script because the context may be different.
083                //but don't bother loading parsing the class again
084                Script s = InvokerHelper.createScript(scriptClass, context);
085                return s.run();
086            } catch (Exception e) {
087                throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
088            }
089        }
090    
091        /**
092         * Execute a script.
093         */
094        public void exec(String source, int lineNo, int columnNo, Object script) throws BSFException {
095            try {
096                //          shell.run(script.toString(), source, EMPTY_ARGS);
097    
098                Class scriptClass = (Class) execScripts.get(script);
099                if (scriptClass == null) {
100                    scriptClass = loader.parseClass(new ByteArrayInputStream(script.toString().getBytes()), source);
101                    execScripts.put(script, scriptClass);
102                } else {
103                    System.out.println("exec() - Using cached version of class...");
104                }
105                InvokerHelper.invokeMethod(scriptClass, "main", EMPTY_ARGS);
106            } catch (Exception e) {
107                System.err.println("BSF trace");
108                e.printStackTrace(System.err);
109                throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
110            }
111        }
112    
113        /**
114         * Initialize the engine.
115         */
116        public void initialize(final BSFManager mgr, String lang, Vector declaredBeans) throws BSFException {
117            super.initialize(mgr, lang, declaredBeans);
118            parent = mgr.getClassLoader();
119            if (parent == null)
120                parent = GroovyShell.class.getClassLoader();
121            final ClassLoader finalParent = parent;
122            this.loader =
123                    (GroovyClassLoader) AccessController.doPrivileged(new PrivilegedAction() {
124                        public Object run() {
125                            CompilerConfiguration configuration = new CompilerConfiguration();
126                            configuration.setClasspath(mgr.getClassPath());
127                            return new GroovyClassLoader(finalParent, configuration);
128                        }
129                    });
130            execScripts = new HashMap();
131            evalScripts = new HashMap();
132            context = shell.getContext();
133            // create a shell
134    
135            // register the mgr with object name "bsf"
136            context.setVariable("bsf", new BSFFunctions(mgr, this));
137    
138            int size = declaredBeans.size();
139            for (int i = 0; i < size; i++) {
140                declareBean((BSFDeclaredBean) declaredBeans.elementAt(i));
141            }
142        }
143    }