calculate Cookie Size in PHP

Question

I wanted to read the cookie and calculate its length on server side using php, but can't find any direct method to do so. So how to achieve this task ?

4 kilobytes per cookie, where the name and the OPAQUE_STRING combine to form the 4 kilobyte limit. — NullPoiиteя, Apr 01 '13 at 09:08

Dino Babu · Answer 1 · 2013-04-01T09:24:12.047

4

what about this ?

setcookie("user", "Dino babu kannampuzha", time() + 3600);

if (isset($_COOKIE["user"])) {
  $data = $_COOKIE["user"];
  $serialized_data = serialize($data);
  $size = strlen($serialized_data);
  echo 'Length : ' . strlen($data);
  echo "<br/>";
  echo 'Size : ' . ($size * 8 / 1024) . ' Kb';
}

// Output

Length : 21
Size : 0.232 Kb

edited Apr 01 '13 at 09:24

answered Apr 01 '13 at 09:08

Dino Babu

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Note that since the cookie will only be available after the page has been reloaded, the condition will be satisfied only *after* reload. – Boaz Apr 01 '13 at 09:12
@Boaz : yea, u r rite. its just a sample. – Dino Babu Apr 01 '13 at 09:13
1

+1 but does the size limit on cookies include data like expiry time? (which isn't parsed into the $_COOKIE var) – Emissary Apr 01 '13 at 09:13
2

isn't that 1024 instead of 1000 ? – AKS Apr 01 '13 at 09:20
http://extraconversion.com/data-storage/characters/characters-to-bytes.html If 1 character = 1 byte then why you `n*8/1024` ? I'm very bad on math please excuse me, I'm really can't get it. – vee Jun 13 '17 at 05:23

score 2 · Answer 2 · answered Apr 01 '13 at 09:17

2

To get the raw cookies and their length:

$rawCookies = isset($_SERVER['HTTP_COOKIE']) ? $_SERVER['HTTP_COOKIE'] : null;
$rawLength  = strlen($rawCookies);
echo $rawLength;

answered Apr 01 '13 at 09:17

Sverri M. Olsen

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score 0 · Answer 3 · answered Apr 01 '13 at 09:07

0

strlen($_COOKIE['cookie_name'])?

answered Apr 01 '13 at 09:07

Majid Fouladpour

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alwaysLearn · Answer 4 · 2013-04-01T09:25:05.853

0

Not sure if this is what you want but you can try this

$start_memory = memory_get_usage();
$cookie = $_COOKIE['YourCookie'];
echo memory_get_usage() - $start_memory-PHP_INT_SIZE * 8;


    <?php
    setcookie("TestCookie", '10');
    $start = memory_get_usage();
    $cookie = $_COOKIE['TestCookie'];
    echo memory_get_usage() - $start;  //116 bytes   
  ?>

edited Apr 01 '13 at 09:25

answered Apr 01 '13 at 09:18

alwaysLearn

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score 0 · Answer 5 · answered Jun 13 '17 at 05:48

Refer from these resources:
http://extraconversion.com/data-storage/characters/characters-to-bytes.html
Measure string size in Bytes in php
https://mothereff.in/byte-counter

And my screenshot that get cookie size using Firebug.

I use my code from @Dino but change something such as strlen to mb_strlen to support unicode.
It becomes:

$data = $_COOKIE['user'];
$name = 'user';
if (!is_scalar($data)) {
    $data = serialize($data);
}
$size = mb_strlen($data)+mb_strlen($name);
echo 'Cookie name length : ' . mb_strlen($name) . "<br>\n";
echo 'Cookie content length : ' . mb_strlen($data) . "<br>\n";
echo 'Cookie size : ~' . ($size) . ' Bytes<br>'."\n";

Which is almost close to the size appears in Firebug. I really don't understand why the size must (n*8/1024) if we refer from the resources above it just 1 character 1 byte except unicode so I have to use mb_strlen instead of strlen.

calculate Cookie Size in PHP

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