org.eclipse.jetty.util

Class SearchPattern

java.lang.Object

org.eclipse.jetty.util.SearchPattern

public class SearchPattern
extends Object

SearchPattern Fast search for patterns within strings and arrays of bytes. Uses an implementation of the Boyer–Moore–Horspool algorithm with a 256 character alphabet. The algorithm has an average-case complexity of O(n) on random text and O(nm) in the worst case. where: m = pattern length n = length of data to search

Method Summary

Modifier and Type	Method and Description
static SearchPattern	compile(byte[] pattern) Produces a SearchPattern instance which can be used to find matches of the pattern in data
static SearchPattern	compile(String pattern) Produces a SearchPattern instance which can be used to find matches of the pattern in data
int	endsWith(byte[] data, int offset, int length) Search for a partial match of the pattern at the end of the data.
int	getLength()
int	match(byte[] data, int offset, int length) Search for a complete match of the pattern within the data
int	startsWith(byte[] data, int offset, int length, int matched) Search for a possibly partial match of the pattern at the start of the data.

Methods inherited from class java.lang.Object

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

Method Detail

compile

public static SearchPattern compile(byte[] pattern)

Produces a SearchPattern instance which can be used to find matches of the pattern in data

Parameters:

pattern - byte array containing the pattern

Returns:

a new SearchPattern instance using the given pattern

compile

public static SearchPattern compile(String pattern)

Produces a SearchPattern instance which can be used to find matches of the pattern in data

Parameters:

pattern - string containing the pattern

Returns:

a new SearchPattern instance using the given pattern

match

public int match(byte[] data,
                 int offset,
                 int length)

Search for a complete match of the pattern within the data

Parameters:

data - The data in which to search for. The data may be arbitrary binary data, but the pattern will always be StandardCharsets.US_ASCII encoded.

offset - The offset within the data to start the search

length - The length of the data to search

Returns:

The index within the data array at which the first instance of the pattern or -1 if not found

endsWith

public int endsWith(byte[] data,
                    int offset,
                    int length)

Search for a partial match of the pattern at the end of the data.

Parameters:

data - The data in which to search for. The data may be arbitrary binary data, but the pattern will always be StandardCharsets.US_ASCII encoded.

offset - The offset within the data to start the search

length - The length of the data to search

Returns:

the length of the partial pattern matched and 0 for no match.

startsWith

public int startsWith(byte[] data,
                      int offset,
                      int length,
                      int matched)

Search for a possibly partial match of the pattern at the start of the data.

Parameters:

data - The data in which to search for. The data may be arbitrary binary data, but the pattern will always be StandardCharsets.US_ASCII encoded.

offset - The offset within the data to start the search

length - The length of the data to search

matched - The length of the partial pattern already matched

Returns:

the length of the partial pattern matched and 0 for no match.

getLength

public int getLength()

Returns:

The length of the pattern in bytes.