NAME
    Digest::xxHash - xxHash Implementation For Perl

SYNOPSIS
        use Digest::xxHash qw[xxhash xxhash_hex];

        my $hash = xxhash( $data, $seed );
        my $hex  = xxhash_hex( $data, $seed );
    
        # OO remix!
    
        my $digest = Digest::xxHash->new( $seed );
        $digest->add( $data );
        $digest->add( $more_data );
        my $xxhash = $digest->digest( );
        my $xxhex  = $digest->digest_hex( );

DESCRIPTION
    This module provides both a functional and an OO interface to xxHash
    functions. xxHash is an extremely fast (and likely very weak) algorithm
    that claims to work at speeds close to RAM limits.

FUNCTIONAL INTERFACE
    These functions are easy to use but aren't very flexible.

  $h = xxhash( $data, $seed )
    Calculates a 32 bit hash.

  $h = xxhash_hex( $data, $seed )
    Calculates a 32 bit hash and returns it as a hex string.

OO INTERFACE
    The OO interface is a lot more flexible but less succinct.

  $d = Digest::xxHash->new( $seed )
    Returns a new Digest::xxHash object. This is a simple constructor.

  $d->add( $data )
    Adds data to the spool that will eventually be hashed. You may call this
    as many times as needed.

  $d->reset( )
    This will reset the data addedadd( $data )"> to the object. This is
    great if you want to hash several pieces of data with the same seed.

  $h = $d->digest( )
    Calculates a 32 bit hash of the data addedadd( $data )"> to the object.

  $h = $d->digest_hex( )
    Calculates a 32 bit hash of the data addedadd( $data )"> to the object
    and returns it as a hex string.

SPEED
    The strength of xxHash isn't very well documented but it's fast.
    According to the xxhash project's website, when run in a single thread
    on a 32bit Windows 7 box with a 3GHz Core 2 Duo processor, xxhash looks
    a little like:

        Name            Speed       Q.Score   Author
        xxHash          5.4 GB/s     10
        MumurHash 3a    2.7 GB/s     10       Austin Appleby
        SpookyHash      2.0 GB/s     10       Bob Jenkins
        SBox            1.4 GB/s      9       Bret Mulvey
        Lookup3         1.2 GB/s      9       Bob Jenkins
        CityHash64      1.05 GB/s    10       Pike & Alakuijala
        FNV             0.55 GB/s     5       Fowler, Noll, Vo
        CRC32           0.43 GB/s     9
        MD5-32          0.33 GB/s    10       Ronald L. Rivest
        SHA1-32         0.28 GB/s    10

    Q.Score is a measure of "quality" of the hash function. It depends on
    successfully passing SMHasher test set
    <http://code.google.com/p/smhasher/wiki/SMHasher>. 10 is a perfect
    score. Hash functions with a Q.score < 5 are not listed in this table.

LICENSE
    xxxHash is covered by the BSD license.

    I don't actually care about the wrapper I've written.

AUTHOR
    Sanko Robinson <sanko@cpan.org>

    xxHash by Yann Collet.

