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1   /*
2    * $Id: CachingGroovyEngine.java,v 1.4 2004/05/17 22:27:11 glaforge Exp $
3    * 
4    * Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5    * 
6    * Redistribution and use of this software and associated documentation
7    * ("Software"), with or without modification, are permitted provided that the
8    * following conditions are met: 1. Redistributions of source code must retain
9    * copyright statements and notices. Redistributions must also contain a copy
10   * of this document. 2. Redistributions in binary form must reproduce the above
11   * copyright notice, this list of conditions and the following disclaimer in
12   * the documentation and/or other materials provided with the distribution. 3.
13   * The name "groovy" must not be used to endorse or promote products derived
14   * from this Software without prior written permission of The Codehaus. For
15   * written permission, please contact info@codehaus.org. 4. Products derived
16   * from this Software may not be called "groovy" nor may "groovy" appear in
17   * their names without prior written permission of The Codehaus. "groovy" is a
18   * registered trademark of The Codehaus. 5. Due credit should be given to The
19   * Codehaus - http://groovy.codehaus.org/
20   * 
21   * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
22   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24   * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
25   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
28   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
31   * DAMAGE.
32   *  
33   */
34  package org.codehaus.groovy.bsf;
35  
36  import groovy.lang.GroovyClassLoader;
37  import groovy.lang.GroovyShell;
38  import groovy.lang.Script;
39  import groovy.lang.Binding;
40  
41  import java.io.ByteArrayInputStream;
42  import java.security.AccessController;
43  import java.security.PrivilegedAction;
44  import java.util.HashMap;
45  import java.util.Map;
46  import java.util.Vector;
47  
48  import org.apache.bsf.BSFDeclaredBean;
49  import org.apache.bsf.BSFException;
50  import org.apache.bsf.BSFManager;
51  import org.apache.bsf.util.BSFFunctions;
52  import org.codehaus.groovy.runtime.InvokerHelper;
53  import org.codehaus.groovy.control.CompilerConfiguration;
54  
55  /***
56   * A Caching implementation of the GroovyEngine
57   * 
58   * @author James Birchfield
59   */
60  public class CachingGroovyEngine extends GroovyEngine {
61      private static final String[] EMPTY_ARGS = {
62      };
63  
64      private Map evalScripts;
65      private Map execScripts;
66      private Binding context;
67      private ClassLoader parent;
68      private GroovyClassLoader loader;
69  
70  
71      /***
72       * Evaluate an expression.
73       */
74      public Object eval(String source, int lineNo, int columnNo, Object script) throws BSFException {
75          try {
76              //          Object result = shell.evaluate(script.toString(), source);
77              Class scriptClass = (Class) evalScripts.get(script);
78              if (scriptClass == null) {
79                  scriptClass = loader.parseClass(new ByteArrayInputStream(script.toString().getBytes()), source);
80                  evalScripts.put(script, scriptClass);
81              }
82              else {
83                  System.out.println("eval() - Using cached script...");
84              }
85              //can't cache the script because the context may be different.
86              //but don't bother loading parsing the class again
87              Script s = InvokerHelper.createScript(scriptClass, context);
88              return s.run();
89          }
90          catch (Exception e) {
91              e.printStackTrace();
92              throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
93          }
94      }
95  
96      /***
97       * Execute a script.
98       */
99      public void exec(String source, int lineNo, int columnNo, Object script) throws BSFException {
100         try {
101             //          shell.run(script.toString(), source, EMPTY_ARGS);
102 
103             Class scriptClass = (Class) execScripts.get(script);
104             if (scriptClass == null) {
105                 scriptClass = loader.parseClass(new ByteArrayInputStream(script.toString().getBytes()), source);
106                 execScripts.put(script, scriptClass);
107             }
108             else {
109                 System.out.println("exec() - Using cached version of class...");
110             }
111             InvokerHelper.invokeMethod(scriptClass, "main", EMPTY_ARGS);
112         }
113         catch (Exception e) {
114             e.printStackTrace();
115             throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
116         }
117     }
118 
119     /***
120      * Initialize the engine.
121      */
122     public void initialize(final BSFManager mgr, String lang, Vector declaredBeans) throws BSFException {
123         super.initialize(mgr, lang, declaredBeans);
124         parent = mgr.getClassLoader();
125         if (parent == null)
126             parent = GroovyShell.class.getClassLoader();
127         final ClassLoader finalParent = parent;
128         this.loader = 
129         	(GroovyClassLoader) AccessController.doPrivileged(new PrivilegedAction() {
130         		public Object run() {
131                     CompilerConfiguration configuration = new CompilerConfiguration();
132                     configuration.setClasspath(mgr.getClassPath());
133                     return new GroovyClassLoader(finalParent, configuration);
134         		}
135         	});
136         execScripts = new HashMap();
137         evalScripts = new HashMap();
138         context = shell.getContext();
139         // create a shell
140 
141         // register the mgr with object name "bsf"
142         context.setVariable("bsf", new BSFFunctions(mgr, this));
143 
144         int size = declaredBeans.size();
145         for (int i = 0; i < size; i++) {
146             declareBean((BSFDeclaredBean) declaredBeans.elementAt(i));
147         }
148     }
149 }