net.minecraftforge.fml.repackage.com.nothome.delta

Class Checksum

java.lang.Object

net.minecraftforge.fml.repackage.com.nothome.delta.Checksum

public class Checksum
extends java.lang.Object

Checksum computation class.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Map<java.lang.Long,java.lang.Integer>	checksums
(package private) static boolean	debug
private static char[]	single_hash

Constructor Summary

Constructors

Constructor and Description
Checksum(SeekableSource source, int chunkSize) Initialize checksums for source.

Method Summary

Modifier and Type	Method and Description
int	findChecksumIndex(long hashf) Finds the index of a checksum.
static char[]	getSingleHash() 256 random hash values.
static long	incrementChecksum(long checksum, byte out, byte in, int chunkSize) Increments a checksum.
static long	queryChecksum(java.nio.ByteBuffer bb, int len) Finds the checksum computed from the buffer.
private static long	queryChecksum0(java.nio.ByteBuffer bb, int len)
java.lang.String	toString() Returns a debug String.

Methods inherited from class java.lang.Object

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

Field Detail

debug

static final boolean debug

See Also:

Constant Field Values

checksums

private java.util.Map<java.lang.Long,java.lang.Integer> checksums

single_hash

private static final char[] single_hash

Constructor Detail

Checksum

public Checksum(SeekableSource source,
                int chunkSize)
         throws java.io.IOException

Initialize checksums for source. The checksum for the chunkSize bytes at offset chunkSize * i is inserted into a hash map.

Throws:

java.io.IOException

Method Detail

queryChecksum

public static long queryChecksum(java.nio.ByteBuffer bb,
                                 int len)

Finds the checksum computed from the buffer. Marks, gets, then resets the buffer.

queryChecksum0

private static long queryChecksum0(java.nio.ByteBuffer bb,
                                   int len)

incrementChecksum

public static long incrementChecksum(long checksum,
                                     byte out,
                                     byte in,
                                     int chunkSize)

Increments a checksum.

Parameters:

checksum - initial checksum

out - byte leaving view

in - byte entering view

chunkSize - size of chunks

Returns:

new checksum

getSingleHash

public static char[] getSingleHash()

256 random hash values.

findChecksumIndex

public int findChecksumIndex(long hashf)

Finds the index of a checksum.

toString

public java.lang.String toString()

Returns a debug String.

Overrides:

toString in class java.lang.Object