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1   /*
2    * $Id: CachingGroovyEngine.java,v 1.6 2005/08/20 19:02:15 blackdrag 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.Binding;
37  import groovy.lang.GroovyClassLoader;
38  import groovy.lang.GroovyShell;
39  import groovy.lang.Script;
40  import org.apache.bsf.BSFDeclaredBean;
41  import org.apache.bsf.BSFException;
42  import org.apache.bsf.BSFManager;
43  import org.apache.bsf.util.BSFFunctions;
44  import org.codehaus.groovy.control.CompilerConfiguration;
45  import org.codehaus.groovy.runtime.InvokerHelper;
46  
47  import java.io.ByteArrayInputStream;
48  import java.security.AccessController;
49  import java.security.PrivilegedAction;
50  import java.util.HashMap;
51  import java.util.Map;
52  import java.util.Vector;
53  
54  /***
55   * A Caching implementation of the GroovyEngine
56   *
57   * @author James Birchfield
58   */
59  public class CachingGroovyEngine extends GroovyEngine {
60      private static final Object[] EMPTY_ARGS = new Object[]{new String[]{}};
61  
62      private Map evalScripts;
63      private Map execScripts;
64      private Binding context;
65      private ClassLoader parent;
66      private GroovyClassLoader loader;
67  
68  
69      /***
70       * Evaluate an expression.
71       */
72      public Object eval(String source, int lineNo, int columnNo, Object script) throws BSFException {
73          try {
74              //          Object result = shell.evaluate(script.toString(), source);
75              Class scriptClass = (Class) evalScripts.get(script);
76              if (scriptClass == null) {
77                  scriptClass = loader.parseClass(new ByteArrayInputStream(script.toString().getBytes()), source);
78                  evalScripts.put(script, scriptClass);
79              } else {
80                  System.out.println("eval() - Using cached script...");
81              }
82              //can't cache the script because the context may be different.
83              //but don't bother loading parsing the class again
84              Script s = InvokerHelper.createScript(scriptClass, context);
85              return s.run();
86          } catch (Exception e) {
87              throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
88          }
89      }
90  
91      /***
92       * Execute a script.
93       */
94      public void exec(String source, int lineNo, int columnNo, Object script) throws BSFException {
95          try {
96              //          shell.run(script.toString(), source, EMPTY_ARGS);
97  
98              Class scriptClass = (Class) execScripts.get(script);
99              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 }