Albert L.G. Blog!: PageRank revised

Domingo 22 de Agosto, 2004

PageRank revised

Como habreis podido observar, en el menú de la derecha, encima del calendario, os muestro el PageRank de mi weblog... ¡sin necesidad de tener la ToolBar de Google!

¿Y qué significa eso? Pues que utilizo un código PHP, junto con SSI para calcularlo y mostrároslo.

¿Quereis ver el código?

define('GMAG', 0xE6359A60);

//unsigned shift right

function zeroFill($a, $b){

  $z = hexdec(80000000);

  if ($z & $a){

    $a = ($a>>1);

    $a &= (~$z);

    $a |= 0x40000000;

    $a = ($a>>($b-1));

  }else{

    $a = ($a>>$b);

  }

  return $a;

}

function mix($a,$b,$c){

  $a -= $b; $a -= $c; $a ^= (zeroFill($c,13));

  $b -= $c; $b -= $a; $b ^= ($a<<8);

  $c -= $a; $c -= $b; $c ^= (zeroFill($b,13));

  $a -= $b; $a -= $c; $a ^= (zeroFill($c,12));

  $b -= $c; $b -= $a; $b ^= ($a<<16);

  $c -= $a; $c -= $b; $c ^= (zeroFill($b,5));

  $a -= $b; $a -= $c; $a ^= (zeroFill($c,3));

  $b -= $c; $b -= $a; $b ^= ($a<<10);

  $c -= $a; $c -= $b; $c ^= (zeroFill($b,15));

return array($a,$b,$c);

}

function GCH($url, $length=null, $init=GMAG){

  if(is_null($length)){

    $length = sizeof($url);

  }

  $a = $b = 0x9E3779B9;

  $c = $init;

  $k = 0;

  $len = $length;

  while($len >= 12){

    $a += ($url[$k+0] +($url[$k+1]<<8) +($url[$k+2]<<16) 

      +($url[$k+3]<<24));

    $b += ($url[$k+4] +($url[$k+5]<<8) +($url[$k+6]<<16) 

      +($url[$k+7]<<24));

    $c += ($url[$k+8] +($url[$k+9]<<8) +($url[$k+10]<<16) 

      +($url[$k+11]<<24));

    $mix = mix($a,$b,$c);

    $a = $mix[0]; $b = $mix[1]; $c = $mix[2];

    $k += 12;

    $len -= 12;

  }

  $c += $length;

  switch($len){  // all the case statements fall through

    case 11: $c+=($url[$k+10]<<24);

    case 10: $c+=($url[$k+9]<<16);

    case 9 : $c+=($url[$k+8]<<8);

      // the first byte of c is reserved for the length

    case 8 : $b+=($url[$k+7]<<24);

    case 7 : $b+=($url[$k+6]<<16);

    case 6 : $b+=($url[$k+5]<<8);

    case 5 : $b+=($url[$k+4]);

    case 4 : $a+=($url[$k+3]<<24);

    case 3 : $a+=($url[$k+2]<<16);

    case 2 : $a+=($url[$k+1]<<8);

    case 1 : $a+=($url[$k+0]);

      // case 0: nothing left to add

  }

  $mix = mix($a,$b,$c);

    // report the result

  return $mix[2];

}

//converts a string into an array of integers (the numeric

//value of the char)

function strord($string){

  for($i=0;$i
    $result[$i] = ord($string{$i});

  }

  return $result;

}

function getPR($_url){

  $url = 'info:'.$_url;

  $ch = GCH(strord($url));

  $url='info:'.urlencode($_url);

  $pr = file("http://www.google.com/search?client=

    navclient-auto&ch=6$ch&ie=UTF-8&oe=UTF-8&

    features=Rank&q=$url");

  $pr_str = implode("", $pr);

  return substr($pr_str,strrpos($pr_str, ":")+1);

}

echo "Mi PR es: ".getPR("http://www.albertlg.com/blog/")."";

?>