NAME

    Crypt::xxHash - xxHash implementation for Perl

SYNOPSIS

        use Crypt::xxHash qw/
                xxhash32 xxhash32_hex
                xxhash64 xxhash64_hex
                xxhash3_64bits xxhash3_64bits_hex
                xxhash3_128bits_hex /;
    
        my $hash = xxhash32( $data, $seed );
        my $hex  = xxhash32_hex( $data, $seed );
    
        my $hash_64 = xxhash64( $data, $seed );
        my $hex_64  = xxhash64_hex( $data, $seed );
    
        my $hash_64 = xxhash3_64bits( $data, $seed );
        my $hex_64  = xxhash3_64bits_hex( $data, $seed );
    
        my $hex_128 = xxhash3_128bits_hex( $data, $seed );

DESCRIPTION

    xxHash is a super fast algorithm that claims to work at speeds close to
    RAM limits. This package provides 32- and 64-bit hash functions. As
    bonus it provides 128-bit hex method.

    This package was inspired by Digest::xxHash, but it includes the fresh
    C code and has some optimisations. Thus all hex methods are implemented
    in Perl XS. Also this module doesn't use Math::Int64 in favor of native
    64 bit digits.

    The used version of xxHash is v0.8.0

 $h = xxhash32( $data, $seed )

    Returns a 32 bit hash.

 $h = xxhash32_hex( $data, $seed )

    Returns a 32 bit hash converted into hex string.

 $h = xxhash64( $data, $seed )

    Returns a 64 bit hash.

 $h = xxhash64_hex( $data, $seed )

    Returns a 64 bit hash converted into hex string

 $h = xxhash3_64bits( $data, $seed )

    Returns a 64 bit hash which calculated by using xxHash3 algorithm.

 $h = xxhash3_64bits_hex( $data, $seed )

    Returns a 64 bit hash which calculated by using xxHash3 algorithm. This
    hash is converted into hex string.

 $h = xxhash3_128its_hex( $data, $seed )

    Returns a 128 bit hash which calculated by using xxHash3 algorithm.
    This hash is converted into hex string.

 $stream = xxhash3_64bits_stream($seed) =head2
 xxhash3_64bits_stream_update($stream, $more_data) =head2 $h =
 xxhash3_64bits_stream_digest($stream) =head2 $h =
 xxhash3_64bits_stream_digest_hex($stream)

    Get a 64 bit hash from segmented data by calling
    xxhash3_64bits_stream_update multiple times.

        sub hash_a_file {
            my($fh) = @_;
            my $stream = xxhash3_64bits_stream(12345);
            my $buf;
            while( read $fh, $buf, 1024 ) {
                xxhash3_64bits_stream_update($stream, $buf);
            }
            return xxhash3_64bits_stream_digest($stream);
            # return xxhash3_64bits_stream_digest_hex($stream); # hex version
        } # the resources $stream occupied will be released here.

SPEED

    There are some official benchmark results can be found on the project
    web-site https://github.com/Cyan4973/xxHash

BENCHMARKS

    Below you can find some benchmarks in comparison with Digest::xxHash.

    The "xxhash32" methods in those two packages have the same realisation.
    so they have the same throughput capacity.

    But other methods have some differences:

                                      Rate Digest::xxHash::xxhash32_hex Crypt::xxHash::xxhash32_hex
    Digest::xxHash::xxhash32_hex 2577320/s                           --                        -54%
    Crypt::xxHash::xxhash32_hex  5543237/s                         115%                          --
    
                                   Rate Digest::xxHash::xxhash64 Crypt::xxHash::xxhash64
    Digest::xxHash::xxhash64   201729/s                       --                    -99%
    Crypt::xxHash::xxhash64  14893617/s                    7283%                      --
    
                                      Rate Digest::xxHash::xxhash64_hex Crypt::xxHash::xxhash64_hex
    Digest::xxHash::xxhash64_hex  185048/s                           --                        -96%
    Crypt::xxHash::xxhash64_hex  4926108/s                        2562%                          --

LICENSE

    xxHash is covered by the BSD license.

AUTHOR

    Chernenko Dmitiry cdn@cpan.org

    xxHash by Yann Collet.