TopLinkMethodWeaver


1   /*
2    * The contents of this file are subject to the terms 
3    * of the Common Development and Distribution License 
4    * (the "License").  You may not use this file except 
5    * in compliance with the License.
6    * 
7    * You can obtain a copy of the license at 
8    * glassfish/bootstrap/legal/CDDLv1.0.txt or 
9    * https://glassfish.dev.java.net/public/CDDLv1.0.html. 
10   * See the License for the specific language governing 
11   * permissions and limitations under the License.
12   * 
13   * When distributing Covered Code, include this CDDL 
14   * HEADER in each file and include the License file at 
15   * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable, 
16   * add the following below this CDDL HEADER, with the 
17   * fields enclosed by brackets "[]" replaced with your 
18   * own identifying information: Portions Copyright [yyyy] 
19   * [name of copyright owner]
20   */
21  // Copyright (c) 2005, 2006, Oracle. All rights reserved.  
22  package oracle.toplink.essentials.internal.weaving;
23  
24  //ASM imports
25  import oracle.toplink.libraries.asm.*;
26  
27  import java.util.Iterator  ;
28  
29  /**
30   * INTERNAL:
31   * 
32   * Used by TopLink's weaving feature to adjust methods to make use of ValueHolders that
33   * have been inserted by TopLinkClassWeaver.
34   * 
35   * For FIELD access, changes references to GETFIELD and PUTFIELD to call newly added 
36   * convenience methods.
37   * 
38   * For Property access, modifies the getters and setters to make use of new ValueHolders
39   * 
40   * Also adds initialization of newly added ValueHolders to constructor.
41   * 
42   */
43  
44  public class TopLinkMethodWeaver extends CodeAdapter implements Constants {
45  
46      protected TopLinkClassWeaver tcw;
47      protected String   methodName;
48      private String   methodDescriptor = null;
49      
50      // used to determine if we are at the first line of a method
51      private boolean methodStarted = false;
52      
53      // Used to control initialization of valueholders in constructor
54      private boolean constructorInitializationDone = false;
55      
56      public TopLinkMethodWeaver(TopLinkClassWeaver tcw, String   methodName, String   methodEscriptor,
57          CodeVisitor cv) {
58          
59          super(cv);
60          this.tcw = tcw;
61          this.methodName = methodName;
62          this.methodDescriptor = methodDescriptor;
63      }
64  
65      /**
66       *  INTERNAL:
67       *  Change GETFIELD and PUTFIELD for fields that use attribute access to make use of new convenience methods
68       *  
69       *  A GETFIELD for an attribute named 'variableName' will be replaced by a call to:
70       *  
71       *  _toplink_getvariableName()
72       *  
73       *  A PUTFIELD for an attribute named 'variableName' will be replaced by a call to:
74       *  
75       *  toplink_setvariableName(variableName)
76       */
77      public void weaveAttributesIfRequired(int opcode, String   owner, String   name, String   desc){
78          AttributeDetails attributeDetails = (AttributeDetails)tcw.classDetails.getAttributeDetailsFromClassOrSuperClass(name);  
79          if (attributeDetails == null || !attributeDetails.isMappedWithAttributeAccess()){
80              super.visitFieldInsn(opcode, owner, name, desc);
81              return;
82          }
83          if (opcode == GETFIELD) {
84              if (attributeDetails != null) {
85                  cv.visitMethodInsn(INVOKEVIRTUAL, tcw.classDetails.getClassName(), "_toplink_get" + name, "()L" + attributeDetails.getReferenceClass().replace('.','/') + ";");
86              } else {
87                  super.visitFieldInsn(opcode, owner, name, desc);
88              }
89          }  else if (opcode == PUTFIELD) {
90              if (attributeDetails != null) {
91                  cv.visitMethodInsn(INVOKEVIRTUAL, tcw.classDetails.getClassName(), "_toplink_set" + name, "(L" + attributeDetails.getReferenceClass().replace('.','/') + ";)V");
92              } else {
93                  super.visitFieldInsn(opcode, owner, name, desc);
94              }
95          }  else {
96              super.visitFieldInsn(opcode, owner, name, desc);
97          }    
98      }
99  
100     /**
101      * INTERNAL:
102      * Add initialization of new ValueHolders to constuctors.  If a ValueHolder called 'variableName' 
103      * has been added, the following line will be added to the constructor.
104      * 
105      *  _toplink_variableName_vh = new ValueHolder();
106      */
107     public void weaveConstructorIfRequired(int opcode, String   owner, String   name, String   desc){
108         if (!constructorInitializationDone && ("<init>".equals(methodName)||"<cinit>".equals(methodName))) {
109                 // look for the superclass initializer and insert the valueholder
110             // initialization after it
111             if (opcode == INVOKESPECIAL && name.startsWith("<init>")) {                  
112                 ClassDetails details = tcw.classDetails;
113                 Iterator   attributes = details.getAttributesMap().keySet().iterator();
114                 while (attributes.hasNext()){
115                     String   key = (String  )attributes.next();
116                         
117                     AttributeDetails attribute = (AttributeDetails)details.getAttributesMap().get(key);
118                     if (attribute.weaveValueHolders() && !attribute.isCollectionMapping() && !attribute.isAttributeOnSuperClass()){
119                         super.visitVarInsn(ALOAD, 0);
120                         super.visitTypeInsn(NEW, "oracle/toplink/essentials/indirection/ValueHolder");
121                         super.visitInsn(DUP);
122                         super.visitMethodInsn(INVOKESPECIAL, "oracle/toplink/essentials/indirection/ValueHolder", "<init>", "()V");
123                         super.visitFieldInsn(PUTFIELD, details.className, "_toplink_" + attribute.attributeName + "_vh", "Loracle/toplink/essentials/indirection/ValueHolderInterface;");                    
124                     }
125                 }
126             }
127             constructorInitializationDone = true;
128         }
129     }
130 
131     /**
132      * INTERNAL:
133      * Modifies getter and setter methods for attributes using property access
134      * 
135      * In a getter method for 'attributeName', the following line is added at the beginning of the method
136      * 
137      * setAttributeName((&lt;AttributeClass&gt;)_toplink_attributeName_vh.getValue());
138      * 
139      * In a setter method, for 'attributeName', the following line is added at the beginning of the method
140      * 
141      * _toplink_attributeName_vh.setValue(methodArgument);
142      * 
143      * TODO: In the end, the call to setValue() should be modified to somehow make use of the result of
144      * the getter method.  This behavior has not yet been implemented.
145      */
146     public void addValueHolderReferencesIfRequired(){
147         if (methodStarted){
148             return;
149         }
150         AttributeDetails attributeDetails = (AttributeDetails)tcw.classDetails.getGetterMethodToAttributeDetails().get(methodName);
151         if (attributeDetails != null && !attributeDetails.isAttributeOnSuperClass()){
152             cv.visitVarInsn(ALOAD, 0);
153             cv.visitVarInsn(ALOAD, 0);
154             cv.visitFieldInsn(GETFIELD, tcw.classDetails.getClassName(), "_toplink_" + attributeDetails.getAttributeName() + "_vh", TopLinkClassWeaver.VHI_SIGNATURE);
155             cv.visitMethodInsn(INVOKEINTERFACE, TopLinkClassWeaver.VHI_SHORT_SIGNATURE, "getValue", "()Ljava/lang/Object;");
156             cv.visitTypeInsn(CHECKCAST, attributeDetails.getReferenceClass().replace('.','/'));
157             cv.visitMethodInsn(INVOKEVIRTUAL, tcw.classDetails.getClassName(), attributeDetails.getSetterMethodName(), "(L" + attributeDetails.getReferenceClass().replace('.','/') + ";)V");
158         } else {
159             attributeDetails = (AttributeDetails)tcw.classDetails.getSetterMethodToAttributeDetails().get(methodName);
160             if (attributeDetails != null){
161                 cv.visitVarInsn(ALOAD, 0);
162                 cv.visitFieldInsn(GETFIELD, tcw.classDetails.getClassName(), "_toplink_" + attributeDetails.getAttributeName() + "_vh", "Loracle/toplink/essentials/indirection/ValueHolderInterface;");
163                 cv.visitVarInsn(ALOAD, 1);
164                 cv.visitMethodInsn(INVOKEINTERFACE, TopLinkClassWeaver.VHI_SHORT_SIGNATURE, "setValue", "(Ljava/lang/Object;)V");
165             }
166         }
167     }
168 
169     public void visitInsn (final int opcode) {
170         addValueHolderReferencesIfRequired();
171         methodStarted = true;
172         super.visitInsn(opcode);
173     }
174 
175     public void visitIntInsn (final int opcode, final int operand) {
176         addValueHolderReferencesIfRequired();
177         methodStarted = true;
178         cv.visitIntInsn(opcode, operand);
179     }
180 
181     public void visitVarInsn (final int opcode, final int var) {
182         addValueHolderReferencesIfRequired();
183         methodStarted = true;
184         cv.visitVarInsn(opcode, var);
185     }
186 
187     public void visitTypeInsn (final int opcode, final String   desc) {
188         addValueHolderReferencesIfRequired();
189         methodStarted = true;
190         cv.visitTypeInsn(opcode, desc);
191     }
192 
193     public void visitFieldInsn (final int opcode, final String   owner, final String   name, final String   desc){
194         addValueHolderReferencesIfRequired();
195         methodStarted = true;
196         weaveAttributesIfRequired(opcode, owner, name, desc);
197     }
198 
199     public void visitMethodInsn (final int opcode, final String   owner, final String   name, final String   desc){
200         addValueHolderReferencesIfRequired();
201         methodStarted = true;
202         super.visitMethodInsn(opcode, owner, name, desc);     
203         weaveConstructorIfRequired(opcode, owner, name, desc);
204     }
205 
206     public void visitJumpInsn (final int opcode, final Label label) {
207         addValueHolderReferencesIfRequired();
208         methodStarted = true;
209         cv.visitJumpInsn(opcode, label);
210     }
211 
212     public void visitLabel (final Label label) {
213         cv.visitLabel(label);
214     }
215 
216     public void visitLdcInsn (final Object   cst) {
217         addValueHolderReferencesIfRequired();
218         methodStarted = true;
219         cv.visitLdcInsn(cst);
220     }
221 
222     public void visitIincInsn (final int var, final int increment) {
223         addValueHolderReferencesIfRequired();
224         methodStarted = true;
225         cv.visitIincInsn(var, increment);
226     }
227 
228     public void visitTableSwitchInsn (final int min, final int max, final Label dflt, final Label labels[]){
229         addValueHolderReferencesIfRequired();
230         methodStarted = true;
231         cv.visitTableSwitchInsn(min, max, dflt, labels);
232     }
233 
234     public void visitLookupSwitchInsn (final Label dflt, final int keys[], final Label labels[]){
235         addValueHolderReferencesIfRequired();
236         methodStarted = true;
237         cv.visitLookupSwitchInsn(dflt, keys, labels);
238     }
239 
240     public void visitMultiANewArrayInsn (final String   desc, final int dims) {
241         addValueHolderReferencesIfRequired();
242         methodStarted = true;
243         cv.visitMultiANewArrayInsn(desc, dims);
244     }
245 
246     public void visitTryCatchBlock (final Label start, final Label end,final Label handler, final String   type){
247         addValueHolderReferencesIfRequired();
248         methodStarted = true;
249         cv.visitTryCatchBlock(start, end, handler, type);
250     }
251 
252     public void visitMaxs (final int maxStack, final int maxLocals) {
253         addValueHolderReferencesIfRequired();
254         methodStarted = true;
255         cv.visitMaxs(0, 0);
256     }
257 
258     public void visitLocalVariable (final String   name, final String   desc, final Label start, final Label end, final int index){
259         addValueHolderReferencesIfRequired();
260         methodStarted = true;
261         cv.visitLocalVariable(name, desc, start, end, index);
262     }
263 
264     public void visitLineNumber (final int line, final Label start) {
265         cv.visitLineNumber(line, start);
266     }
267 
268     public void visitAttribute (final Attribute attr) {
269         addValueHolderReferencesIfRequired();
270         methodStarted = true;
271         cv.visitAttribute(attr);
272     }
273 
274 
275     // helper methods
276     protected AttributeDetails weaveValueHolders(ClassDetails startingDetails,
277         String   fieldName) {
278         
279         if (startingDetails == null) {
280             return null;
281         } else {
282             AttributeDetails attributeDetails = (AttributeDetails)startingDetails.getAttributesMap().get(fieldName);
283             if (attributeDetails != null && attributeDetails.weaveValueHolders()) {
284                 return attributeDetails;
285             } else {
286                 return weaveValueHolders(startingDetails.getSuperClassDetails(),
287                     fieldName);
288             }
289         }
290     }
291 }
292
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