001    /*
002     * $Id: CachingGroovyEngine.java 4166 2006-10-25 07:07:33Z paulk $
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    import java.util.logging.Logger;
054    import java.util.logging.Level;
055    
056    /**
057     * A Caching implementation of the GroovyEngine
058     *
059     * @author James Birchfield
060     */
061    public class CachingGroovyEngine extends GroovyEngine {
062        private static final Logger LOG = Logger.getLogger(CachingGroovyEngine.class.getName());
063        private static final Object[] EMPTY_ARGS = new Object[]{new String[]{}};
064    
065        private Map evalScripts;
066        private Map execScripts;
067        private Binding context;
068        private GroovyClassLoader loader;
069    
070        /**
071         * Evaluate an expression.
072         */
073        public Object eval(String source, int lineNo, int columnNo, Object script) throws BSFException {
074            try {
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                    LOG.fine("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                    LOG.fine("exec() - Using cached version of class...");
104                }
105                InvokerHelper.invokeMethod(scriptClass, "main", EMPTY_ARGS);
106            } catch (Exception e) {
107                LOG.log(Level.WARNING, "BSF trace", 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            ClassLoader 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            // register the mgr with object name "bsf"
134            context.setVariable("bsf", new BSFFunctions(mgr, this));
135            int size = declaredBeans.size();
136            for (int i = 0; i < size; i++) {
137                declareBean((BSFDeclaredBean) declaredBeans.elementAt(i));
138            }
139        }
140    }