sofya.apps.dejavu
Class BytecodeNodeComparer

java.lang.Object
  sofya.apps.dejavu.NodeComparer
      sofya.apps.dejavu.BytecodeNodeComparer

public class BytecodeNodeComparer
extends NodeComparer

Implementation of NodeComparer which uses the bytecode instruction lists of two nodes to compare them for equivalence.

Version:

10/13/2005

Author:

Sharat Narayan, Sriraam Natarajan, Alex Kinneer

Field Summary

Fields inherited from class sofya.apps.dejavu.NodeComparer

class_

Constructor Summary

BytecodeNodeComparer()

Method Summary

boolean	compareNodes(java.lang.String methodName, Node oldNode, Node newNode) Compares two blocks from the same method in different versions of the program.
java.lang.String	getCallMethodName(java.lang.String methodName, Node oldCallNode, Node newCallNode) Retrieves the name of the method called by a call node.
void	setComparisonClass(ClassPair clazz) Sets the class from which node instruction lists are read for comparison.

Methods inherited from class sofya.apps.dejavu.NodeComparer

getComparisonClass

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BytecodeNodeComparer

public BytecodeNodeComparer()

Method Detail

setComparisonClass

public void setComparisonClass(ClassPair clazz)
                        throws java.io.IOException

Sets the class from which node instruction lists are read for comparison.

Overrides:

setComparisonClass in class NodeComparer

Parameters:

clazz - Structure containing the name of the class and the locations from which the class can be loaded in the respective versions of the program.

Throws:

java.io.IOException - If both versions of the specified class cannot be read. Either the name of the class is invalid or a path to one or both of the versions of the class is invalid.

getCallMethodName

public java.lang.String getCallMethodName(java.lang.String methodName,
                                          Node oldCallNode,
                                          Node newCallNode)
                                   throws MethodNotFoundException,
                                          java.lang.IllegalArgumentException,
                                          java.lang.NullPointerException

Retrieves the name of the method called by a call node.

Specified by:

getCallMethodName in class NodeComparer

Parameters:

methodName - Name of the method containing the call node.

oldCallNode - Call node in the original graph from which the name of the called method should be retrieved. May be null if newCallNode is non-null.

newCallNode - Call node in the modified graph from which the name of the called method should be retrieved. May be null if oldCallNode is non-null.

Returns:

The name of the method which is called by the invoke instruction contained in one of the given call nodes.

Throws:

MethodNotFoundException - If methodName does not refer to a method that can be found in either the original or modified versions of the class.

java.lang.IllegalArgumentException - If a node is not a call node.

java.lang.NullPointerException - If both oldCallNode and newCallNode are null.

compareNodes

public boolean compareNodes(java.lang.String methodName,
                            Node oldNode,
                            Node newNode)
                     throws MethodNotFoundException,
                            java.lang.NullPointerException

Compares two blocks from the same method in different versions of the program.

Specified by:

compareNodes in class NodeComparer

Parameters:

methodName - Name of the method containing the blocks to be compared.

oldNode - Block in the old version of the program to be compared to newNode.

newNode - Block in the new version of the program to be compared to oldNode.

Returns:

true if the two blocks are identical, false otherwise.

Throws:

MethodNotFoundException - If methodName does not refer to a valid method in the class.

java.lang.NullPointerException - If either oldNode or newNode is null.