org.aspectj.org.eclipse.jdt.internal.core.nd

Class StreamHasher

java.lang.Object

org.aspectj.org.eclipse.jdt.internal.core.nd.StreamHasher

public final class StreamHasher
extends java.lang.Object

Computes a 64-bit hash value of a character stream that can be supplied one chunk at a time. Usage:

   StreamHasher hasher = new StreamHasher();
   for (long offset = 0; offset < streamLength; offset += chunkLength) {
     hasher.addChunk(offset, chunkOfCharacters);
   }
   int64 hashValue = hasher.computeHash();
 

Based on lookup3.c by Bob Jenkins from "http://burtleburtle.net/bob/c/lookup3.c"

Constructor Summary

Constructors

Constructor and Description
StreamHasher()

Method Summary

Modifier and Type	Method and Description
void	addChunk(char[] chunk) Adds a chunk of data to the hasher.
long	computeHash() Computes and returns the hash value.
static long	hash(java.lang.String str) Computes a 64-bit hash value of a String.

Methods inherited from class java.lang.Object

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

Constructor Detail

StreamHasher

public StreamHasher()

Method Detail

addChunk

public void addChunk(char[] chunk)

Adds a chunk of data to the hasher.

Parameters:

chunk - Contents of the chunk.

computeHash

public long computeHash()

Computes and returns the hash value. Must be called once after the last chunk.

Returns:

The hash value of the character stream.

hash

public static long hash(java.lang.String str)

Computes a 64-bit hash value of a String. The resulting hash value is zero if the string is empty.

Parameters:

str - The string to hash.

Returns:

The hash value.