NAME
    Digest::SipHash - Perl XS interface to the SipHash algorithm

SYNOPSIS
      use Digest::SipHash qw/siphash/;
      my $seed = pack 'C16', 0 .. 0xF;    # 16 chars long
      my $str = "hello world!";
      my ( $lo, $hi ) = siphash( $str, $seed );
      #  $lo = 0x10cf32e0, $hi == 0x7da9cd17
      my $u32 = siphash( $str, $seed )
      #  $u32 = 0x10cf32e0

      use Config;
      if ( $Config{use64bitint} ) {
        use Digest::SipHash qw/siphash64/;
        my $uint64 = siphash64( $str, $seed );    # scalar context;
        # $uint64 == 0x7da9cd1710cf32e0
      }

DESCRIPTION
    SipHash is the default perl hash function for 64 bit builds now.

    <http://perl5.git.perl.org/perl.git/commit/3db6cbfca39da94d152d3e860e2aa79b9c6bb161>

    <https://131002.net/siphash/>

    This module does only one thing - culculates the SipHash value of the
    given string.

EXPORT
    "siphash()", "siphash32()" and "siphash64()" on demand.

    ":all" to all of above

SUBROUTINES/METHODS
  siphash
      my ($hi, $lo) = siphash($str [, $seed]);
      my $uint32    = siphash($str [, $seed]);

    Calculates the SipHash value of $src with $<$seed>.

    If $seed is omitted, it defaults to $Digest:::SipHash::DEFAULT_SEED,
    which is set randomly upon initialization of this module.

    If $seed is set but less than 16 bytes long, it is padded with
    $DEFAULT_SEED.

    To be compatible with 32-bit perl, It returns a pair of 32-bit integers
    instead of a 64-bit integer. Since "Hash::Util::hash_value()" always
    returns the lower 32-bit first so that:

      use Hash::Util qw/hash_seed hash_value/;
      use Digest::SipHash qw/siphash/;
      hash_value($str) == siphash($str, hash_seed()); # scalar context

    always holds true when PERL_HASH_FUN_SIPHASH is in effect.

  siphash32
    just an alias of "siphash".

  siphash64
      my $uint64 = siphash64($str [, $seed]);

    Calculates the SipHash value of $src with $seed in 64-bit. Available on
    64-bit platforms only.

AUTHOR
    Dan Kogai, "<dankogai+cpan at gmail.com>"

BUGS
    Please report any bugs or feature requests to "bug-digest-siphash at
    rt.cpan.org", or through the web interface at
    <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Digest-SipHash>. I will
    be notified, and then you'll automatically be notified of progress on
    your bug as I make changes.

SUPPORT
    You can find documentation for this module with the perldoc command.

        perldoc Digest::SipHash

    You can also look for information at:

    *   RT: CPAN's request tracker (report bugs here)

        <http://rt.cpan.org/NoAuth/Bugs.html?Dist=Digest-SipHash>

    *   AnnoCPAN: Annotated CPAN documentation

        <http://annocpan.org/dist/Digest-SipHash>

    *   CPAN Ratings

        <http://cpanratings.perl.org/d/Digest-SipHash>

    *   Search CPAN

        <http://search.cpan.org/dist/Digest-SipHash/>

SEE ALSO
    Hash::Util, <https://131002.net/siphash/>

ACKNOWLEDGEMENTS
    SipHash: a fast short-input PRF

    by Jean-Philippe Aumasson & Daniel J. Bernstein

    <https://131002.net/siphash/>

LICENSE AND COPYRIGHT
  csiphash.c
    Copyright (c) 2013 Marek Majkowski

    MIT License <http://opensource.org/licenses/MIT>

    <https://github.com/majek/csiphash>

  The rest of this module
    Copyright 2013 Dan Kogai.

    This program is free software; you can redistribute it and/or modify it
    under the terms of the the Artistic License (2.0). You may obtain a copy
    of the full license at:

    <http://www.perlfoundation.org/artistic_license_2_0>

    Any use, modification, and distribution of the Standard or Modified
    Versions is governed by this Artistic License. By using, modifying or
    distributing the Package, you accept this license. Do not use, modify,
    or distribute the Package, if you do not accept this license.

    If your Modified Version has been derived from a Modified Version made
    by someone other than you, you are nevertheless required to ensure that
    your Modified Version complies with the requirements of this license.

    This license does not grant you the right to use any trademark, service
    mark, tradename, or logo of the Copyright Holder.

    This license includes the non-exclusive, worldwide, free-of-charge
    patent license to make, have made, use, offer to sell, sell, import and
    otherwise transfer the Package with respect to any patent claims
    licensable by the Copyright Holder that are necessarily infringed by the
    Package. If you institute patent litigation (including a cross-claim or
    counterclaim) against any party alleging that the Package constitutes
    direct or contributory patent infringement, then this Artistic License
    to you shall terminate on the date that such litigation is filed.

    Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER
    AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES.
    THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
    PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY
    YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR
    CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR
    CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE,
    EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

