Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@cassandra.apache.org
Received-SPF: pass (nike.apache.org: domain of juho.makinen@gmail.com
 designates 209.85.214.44 as permitted sender)
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type:content-transfer-encoding;
        b=ZAdLNg8LXP8F0rVKy6rF5WOPZ40iVFacJSR8Qvc/4Otjy6HehOWcNOoCyicQbUmvBP
         JTtVuSQI9v9UZXZACb/D1mUUdOZhliQJm6Xt+D4UYD3eTBFs1InH21fEAX1Wha4mme9I
         lgkVtHXE0a8jh0JrmDXW75jTrdcyQQqutljUw=
MIME-Version: 1.0
In-Reply-To: <AANLkTimepszjeZyjI65ZQmQRP5_k8xU5NQvFZKj-WDFC@mail.gmail.com>
References: <AANLkTikK8OyOAFGSwkM3pqWqEhLEeThcPHjeQ2Uj_Pjg@mail.gmail.com>
	<AANLkTimepszjeZyjI65ZQmQRP5_k8xU5NQvFZKj-WDFC@mail.gmail.com>
Date: Wed, 7 Jul 2010 15:26:37 +0300
Message-ID: <AANLkTil5bruOsXGDYJhEMSttc1BWWCbRzqJEHtI-8fjO@mail.gmail.com>
Subject: Re: a_long_is_exactly_8_bytes
From: =?ISO-8859-1?Q?Juho_M=E4kinen?= <juho.makinen@gmail.com>
To: user@cassandra.apache.org
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

Hello.

I added that code and it works on our x86_64 bit Intel machine (just
tested with your test.php). What environment are you using? I haven't
tested the code on a 32bit machine and I believe that it will not work
there. I should have propably added a note to the wiki that it wont
work on 32bit environment.

 - Juho M=E4kinen

On Wed, Jul 7, 2010 at 2:08 PM, john xie <shanfenggood@gmail.com> wrote:
>
>
> http://wiki.apache.org/cassandra/FAQ#a_long_is_exactly_8_bytes
>
>         /**
>          * Takes php integer and packs it to 64bit (8 bytes) long big end=
ian
> binary representation.
>          * @param  $x integer
>          * @return string eight bytes long binary repersentation of the
> integer in big endian order.
>          */
>         public static function pack_longtype($x) {
>                 return pack('C8', ($x >> 56) & 0xff, ($x >> 48) & 0xff, (=
$x
>>> 40) & 0xff, ($x >> 32) & 0xff,
>                                 ($x >> 24) & 0xff, ($x >> 16) & 0xff, ($x=
 >>
> 8) & 0xff, $x & 0xff);
>         }
>
>         /**
>          * Takes eight bytes long big endian binary representation of an
> integer and unpacks it to a php integer.
>          * @param  $x
>          * @return php integer
>          */
>         public static function unpack_longtype($x) {
>                 $a =3D unpack('C8', $x);
>                 return ($a[1] << 56) + ($a[2] << 48) + ($a[3] << 40) +
> ($a[4] << 32) + ($a[5] << 24) + ($a[6] << 16) + ($a[7] << 8) + $a[8];
>         }
>
> test.php:
>
> =A0$input=3D1;
>
> =A0$output=3Dunpack_longtype(pack_longtype($input));
>
> =A0=A0print "input=3D".$input." but output =3D ".$output."\n";
>
> =A0$input=3D2;
>
> =A0$output=3Dunpack_longtype(pack_longtype($input));
>
> =A0print "input=3D".$input." but output =3D ".$output."\n";
>
> =A0 $input=3D3;
>
> =A0$output=3Dunpack_longtype(pack_longtype($input));
>
> =A0print "input=3D".$input." but output =3D ".$output."\n";
>
> but in log file:
>
> input=3D1 but output =3D 2
>
> input=3D2 but output =3D 4
>
> input=3D3 but output =3D 6
>
>
>