Package ghidra.util.bytesearch

Class PatternPairSet

java.lang.Object

ghidra.util.bytesearch.PatternPairSet

public class PatternPairSet
extends java.lang.Object

A set of "pre" DittedBitSequences and a set of "post" Patterns are paired to form a larger pattern. To match, a sequence from the "pre" sequence set must first match, then one of the "post" patterns is matched relative to the matching "pre" pattern. This class is really a storage object for the patterns and provides a mechanism to read the pre/post patterns from an XML file. The larger pattern has the idea of bits of check, which means the number of bits that are fixed to a value when matching (not don't care). There is a pre pattern bits of check and post pattern bits of check. The bits of check are used to statistically gauge the accuracy of the pattern. An example of the XML format follows: 0xe12fff1. 0xe12fff1e 0x46c0 0xe12fff1e 0xe1a00000 0xe24dd... 11101001 00101101 .1...... ....0000 11101001 00101101 .1...... ....0000 0xe24dd... 11101001 00101101 .1...... ....0000 0x........ 0xe24dd... Note: The post Patterns can also have a set of rules that must be satisfied along with one of the Pattern DittedBitSequence matches.

Constructor Summary

Constructors

Constructor	Description
PatternPairSet()	Construct an empty PatternPairSet.

Method Summary

Modifier and Type	Method	Description
void	createFinalPatterns(java.util.ArrayList<Pattern> finalpats)
void	extractPostPatterns(java.util.ArrayList<Pattern> postpats)	Add this PatternPairSets post patterns to an existing arraylist of patterns.
int	getPostBitsOfCheck()	Get the required number of fixed bits after the prepattern
java.util.ArrayList<Pattern>	getPostPatterns()	Get the "post" parts of the patterns
java.util.ArrayList<DittedBitSequence>	getPreSequences()	Get the "pre" parts of the patterns
int	getTotalBitsOfCheck()	Get the required number of fixed bits in the whole pattern
void	restoreXml(XmlPullParser parser, PatternFactory pfactory)	Restore PatternPairSet from XML pull parser

Methods inherited from class java.lang.Object

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

Constructor Detail

PatternPairSet

public PatternPairSet()

Construct an empty PatternPairSet. Use XML to initialize the pattern sets.

Method Detail

createFinalPatterns

public void createFinalPatterns(java.util.ArrayList<Pattern> finalpats)

extractPostPatterns

public void extractPostPatterns(java.util.ArrayList<Pattern> postpats)

Add this PatternPairSets post patterns to an existing arraylist of patterns.

Parameters:

postpats - array to add this PatternPairSets post patterns into

restoreXml

public void restoreXml(XmlPullParser parser,
                       PatternFactory pfactory)
                throws java.io.IOException

Restore PatternPairSet from XML pull parser

Parameters:

parser - XML pull parser

pfactory - pattern factory user to construct patterns

Throws:

java.io.IOException - if pull parsing fails

getPreSequences

public java.util.ArrayList<DittedBitSequence> getPreSequences()

Get the "pre" parts of the patterns

Returns:

pre sequences

getPostPatterns

public java.util.ArrayList<Pattern> getPostPatterns()

Get the "post" parts of the patterns

Returns:

post patterns

getPostBitsOfCheck

public int getPostBitsOfCheck()

Get the required number of fixed bits after the prepattern

Returns:

number of post bits

getTotalBitsOfCheck

public int getTotalBitsOfCheck()

Get the required number of fixed bits in the whole pattern

Returns:

number of total fixed bits