```
public final class Diff
extends Object
```
Diff is the main class for the invariant diff program. The invariant diff program outputs the differences between two sets of invariants.
The following is a high-level description of the program. Each input file contains a serialized PptMap or InvMap. PptMap and InvMap are similar structures, in that they both map program points to invariants. However, PptMaps are much more complicated than InvMaps. PptMaps are output by Daikon, and InvMaps are output by this program.
First, if either input is a PptMap, it is converted to an InvMap. Next, the two InvMaps are combined to form a tree. The tree is exactly three levels deep. The first level contains the root, which holds no data. Each node in the second level is a pair of Ppts, and each node in the third level is a pair of Invariants. The tree is constructed by pairing the corresponding Ppts and Invariants in the two PptMaps. Finally, the tree is traversed via the Visitor pattern to produce output. The Visitor pattern makes it easy to extend the program, simply by writing a new Visitor.

Field Summary

Fields
Modifier and Type Field Description

static Logger debug
Debug logger.

Constructor Summary

Constructors
Constructor	Description
`Diff()`
`Diff(boolean examineAllPpts)`
`Diff(boolean examineAllPpts, boolean ignoreNumberedExits)`
`Diff(boolean examineAllPpts, boolean ignoreNumberedExits, @Nullable @ClassGetName String invSortComparator1Classname, @Nullable @ClassGetName String invSortComparator2Classname, @Nullable @ClassGetName String invPairComparatorClassname, Comparator<Invariant> defaultComparator)`
`Diff(boolean examineAllPpts, Comparator<Invariant> c)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`InvMap`	`convertToInvMap(PptMap pptMap)`	Extracts the PptTopLevel and Invariants out of a pptMap, and places them into an InvMap.
`RootNode`	`diffInvMap(InvMap map1, InvMap map2)`	Returns a pair tree of corresponding program points, and corresponding invariants at each program point.
`RootNode`	`diffInvMap(InvMap map1, InvMap map2, boolean includeUnjustified)`	Returns a pair tree of corresponding program points, and corresponding invariants at each program point.
`RootNode`	`diffPptMap(PptMap pptMap1, PptMap pptMap2)`	Diffs two PptMaps by converting them to InvMaps.
`RootNode`	`diffPptMap(PptMap pptMap1, PptMap pptMap2, boolean includeUnjustified)`	Diffs two PptMaps by converting them to InvMaps.
`static void`	`main(String[] args)`	Read two PptMap or InvMap objects from their respective files.
`static void`	`mainHelper(String[] args)`	This does the work of `main(String[])`, but it never calls System.exit, so it is appropriate to be called progrmmatically.
`void`	`setAllInvComparators(Comparator<Invariant> c)`	Use the comparator for sorting both sets and creating the pair tree.
`void`	`setInvPairComparator(Comparator<Invariant> c)`	Use the comparator for creating the pair tree.
`void`	`setInvSortComparator1(Comparator<Invariant> c)`	Use the comparator for sorting the first set.
`void`	`setInvSortComparator2(Comparator<Invariant> c)`	Use the comparator for sorting the second set.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail
- debug
```
public static final Logger debug
```
  Debug logger.

Constructor Detail

Diff
```
public Diff()
```

Diff

public Diff(boolean examineAllPpts)

Diff

public Diff(boolean examineAllPpts,
            Comparator<Invariant> c)

Diff

public Diff(boolean examineAllPpts,
            boolean ignoreNumberedExits)

Diff

public Diff(boolean examineAllPpts,
            boolean ignoreNumberedExits,
            @Nullable @ClassGetName String invSortComparator1Classname,
            @Nullable @ClassGetName String invSortComparator2Classname,
            @Nullable @ClassGetName String invPairComparatorClassname,
            Comparator<Invariant> defaultComparator)
     throws ClassNotFoundException,
            IllegalAccessException,
            InstantiationException,
            InvocationTargetException,
            NoSuchMethodException

Throws:: ClassNotFoundException; IllegalAccessException; InstantiationException; InvocationTargetException; NoSuchMethodException

Method Detail

main

public static void main(String[] args)
                 throws FileNotFoundException,
                        StreamCorruptedException,
                        OptionalDataException,
                        IOException,
                        ClassNotFoundException,
                        IllegalAccessException,
                        InstantiationException,
                        InvocationTargetException,
                        NoSuchMethodException

Read two PptMap or InvMap objects from their respective files. Convert the PptMaps to InvMaps as necessary, and diff the InvMaps.

Throws:: FileNotFoundException; StreamCorruptedException; OptionalDataException; IOException; ClassNotFoundException; IllegalAccessException; InstantiationException; InvocationTargetException; NoSuchMethodException

mainHelper

public static void mainHelper(String[] args)
                       throws FileNotFoundException,
                              StreamCorruptedException,
                              OptionalDataException,
                              IOException,
                              ClassNotFoundException,
                              InstantiationException,
                              IllegalAccessException,
                              InvocationTargetException,
                              NoSuchMethodException

This does the work of main(String[]), but it never calls System.exit, so it is appropriate to be called progrmmatically.

Throws:: FileNotFoundException; StreamCorruptedException; OptionalDataException; IOException; ClassNotFoundException; InstantiationException; IllegalAccessException; InvocationTargetException; NoSuchMethodException

convertToInvMap
```
public InvMap convertToInvMap(PptMap pptMap)
```
Extracts the PptTopLevel and Invariants out of a pptMap, and places them into an InvMap. Maps PptTopLevel to a List of Invariants. The InvMap is a cleaner representation than the PptMap, and it allows us to more easily manipulate the contents. The InvMap contains exactly the elements contained in the PptMap. Conditional program points are also added as keys. Filtering is done when creating the pair tree. The ppts in the InvMap must be sorted, but the invariants need not be sorted.

diffInvMap
```
public RootNode diffInvMap(InvMap map1,
                           InvMap map2)
```
Returns a pair tree of corresponding program points, and corresponding invariants at each program point. This tree can be walked to determine differences between the sets of invariants. Calls diffInvMap and asks to include all justified invariants.

diffInvMap
```
public RootNode diffInvMap(InvMap map1,
                           InvMap map2,
                           boolean includeUnjustified)
```
Returns a pair tree of corresponding program points, and corresponding invariants at each program point. This tree can be walked to determine differences between the sets of invariants. The tree consists of the invariants in map1 and map2. If includeUnjustified is true, the unjustified invariants are included.

diffPptMap
```
public RootNode diffPptMap(PptMap pptMap1,
                           PptMap pptMap2)
```
Diffs two PptMaps by converting them to InvMaps. Provided for compatibiliy with legacy code. Calls diffPptMap and asks to include all invariants.

diffPptMap

public RootNode diffPptMap(PptMap pptMap1,
                           PptMap pptMap2,
                           boolean includeUnjustified)

Diffs two PptMaps by converting them to InvMaps. Provided for compatibiliy with legacy code. If includeUnjustified is true, the unjustified invariants are included.

setAllInvComparators

@EnsuresNonNull({"invSortComparator1","invSortComparator2","invPairComparator"})
public void setAllInvComparators(@UnknownInitialization Diff this,
                                 Comparator<Invariant> c)

Use the comparator for sorting both sets and creating the pair tree.

setInvSortComparator1

@EnsuresNonNull("invSortComparator1")
public void setInvSortComparator1(@UnknownInitialization Diff this,
                                  Comparator<Invariant> c)

Use the comparator for sorting the first set.

setInvSortComparator2

@EnsuresNonNull("invSortComparator2")
public void setInvSortComparator2(@UnknownInitialization Diff this,
                                  Comparator<Invariant> c)

Use the comparator for sorting the second set.

setInvPairComparator

@EnsuresNonNull("invPairComparator")
public void setInvPairComparator(@UnknownInitialization Diff this,
                                 Comparator<Invariant> c)

Use the comparator for creating the pair tree.

Class Diff

Field Summary

Constructor Summary

Method Summary

Methods inherited from class Object

Field Detail

debug

Constructor Detail

Diff

Diff

Diff

Diff

Diff

Method Detail

main

mainHelper

convertToInvMap

diffInvMap

diffInvMap

diffPptMap

diffPptMap

setAllInvComparators

setInvSortComparator1

setInvSortComparator2

setInvPairComparator