com.adobe.internal.pdftoolkit.core.util

Class Utility

java.lang.Object

com.adobe.internal.pdftoolkit.core.util.Utility

public final class Utility
extends Object

Only for internal engineering use. This api can change without notice.

Method Summary

Modifier and Type	Method and Description
static int[]	ComputeKMPNextArray(byte[] key) Only for internal engineering use.
static int	KMPFindFirst(byte[] key, int[] next, byte[] target) Only for internal engineering use.
static long	KMPFindFirst(byte[] key, int[] next, InputByteStream targetstm) Only for internal engineering use.
static boolean	nameInArray(ASName key, ASName[] keys) Only for internal engineering use.

Methods inherited from class java.lang.Object

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

Method Detail

nameInArray

public static boolean nameInArray(ASName key,
                                  ASName[] keys)

Only for internal engineering use. This api can change without notice.

ComputeKMPNextArray

public static int[] ComputeKMPNextArray(byte[] key)

Only for internal engineering use. This api can change without notice. Computes the new seach position for a comparison failure at each point in the search key. The value of the next array is the amount of key that could still be matched if there is a failure at the given position. It gives the index of an earlier part of the key that should be tested next. For example, consider key = ABCABD. If you fail on the 'D' at pattern position 5, you next test against pattern position 2, since the non-D character could have been a 'C'. A value of -1 means the missed character cannot match the first in the pattern, so start looking at the beginning of the pattern, but at the next character in the target.

Parameters:

key - - array of bytes that may occur as a subset of target

KMPFindFirst

public static int KMPFindFirst(byte[] key,
                               int[] next,
                               byte[] target)

Only for internal engineering use. This api can change without notice. Returns the offset in target of the first instance of key. Uses the Knuth, Morris, Pratt linear search algorithm. The "next" array give the position in the pattern to begin searching if there is a failure at the given point in the key.

Parameters:

key - - array of bytes that may occur as a subset of target

next - - KMP failure array

target - - array of bytes to be searched

Returns:

- index of first instance of key in target, -1 if no instance

KMPFindFirst

public static long KMPFindFirst(byte[] key,
                                int[] next,
                                InputByteStream targetstm)
                         throws IOException

Only for internal engineering use. This api can change without notice. Returns the offset in target of the first instance of key. Uses the Knuth, Morris, Pratt linear search algorithm. The "next" array give the position in the pattern to begin searching if there is a failure at the given point in the key.

Parameters:

key - - array of bytes that may occur as a subset of target

next - - KMP failure array

targetstm - - a ByteStream to be searched

Returns:

- index of first instance of key in targetstm, -1 if no instance

Throws:

IOException