珊瑚虫IP库浅析

这不是什么新鲜事情了，很早之前就已经有人做出来了。
就是使用PHP操作纯真IP库或珊瑚虫IP库，根据来访者的IP得到所在的物理位置。

我先帖出代码。然后再慢慢一步步浅析出来。希望对想了解这一块的朋友们有帮助。

Only For PHP5的代码。会继续优化代码的。

class IpLocation{
private $fp;
private $wrydat;
private $wrydat_version;
private $ipnumber;
private $firstip;
private $lastip;
private $ip_range_begin;
private $ip_range_end;
private $country;
private $area;
const REDIRECT_MODE_0 = 0;
const REDIRECT_MODE_1 = 1;
const REDIRECT_MODE_2 = 2;
function __construct(){
$args = func_get_args();
$this->wrydat = func_num_args()>0?$args[0]:'CoralWry.dat';
$this->initialize();
}
function __destruct(){
fclose($this->fp);
}
private function initialize(){
if(file_exists($this->wrydat))
$this->fp = fopen($this->wrydat,'rb');
$this->getipnumber();
$this->getwryversion();
}
public function get($str){
return $this->$str;
}
public function set($str,$val){
$this->$str = $val;
}
private function getbyte($length,$offset=null){
if(!is_null($offset)){
fseek($this->fp,$offset,SEEK_SET);
}
$b = fread($this->fp,$length);
return $b;
}
/**
* 把IP地址打包成二进制数据，以big endian（高位在前）格式打包
* 数据存储格式为 little endian（低位在前） 如：
* 00 28 C6 DA 218.198.40.0 little endian
* 3F 28 C6 DA 218.198.40.0 little endian
* 这样的数据无法作二分搜索查找的比较，所以必须先把获得的IP数据使用strrev转换为big endian
* @param $ip
* @return big endian格式的二进制数据
*/
private function packip($ip){
return pack( "N", intval( ip2long( $ip)));
}

private function getlong($length=4, $offset=null){
$chr=null;
for($c=0;$length%4!=0&&$c $chr .= chr(0);
}
$var = unpack( "Vlong", $this->getbyte($length, $offset).$chr);
return $var['long'];
}

private function getwryversion(){
$length = preg_match("/coral/i",$this->wrydat)?26:30;
$this->wrydat_version = $this->getbyte($length, $this->firstip-$length);
}

private function getipnumber(){
$this->firstip = $this->getlong();
$this->lastip = $this->getlong();
$this->ipnumber = ($this->lastip-$this->firstip)/7+1;
}

private function getstring($data="",$offset=null){
$char = $this->getbyte(1,$offset);
while(ord($char) > 0){
$data .= $char;
$char = $this->getbyte(1);
}
return $data;
}

private function iplocaltion($ip){
$ip = $this->packip($ip);
$low = 0;
$high = $this->ipnumber-1;
$ipposition = $this->lastip;
while($low $t = floor(($low+$high)/2);
if($ip getbyte(4,$this->firstip+$t*7))){
$high = $t - 1;
} else {
if($ip > strrev($this->getbyte(4,$this->getlong(3)))){
$low = $t + 1;
}else{
$ipposition = $this->firstip+$t*7;
break;
}
}
}
return $ipposition;
}
private function getarea(){
$b = $this->getbyte(1);
switch(ord($b)){
case self::REDIRECT_MODE_0 :
return "未知";
break;
case self::REDIRECT_MODE_1:
case self::REDIRECT_MODE_2:
return $this->getstring("",$this->getlong(3));
break;
default:
return $this->getstring($b);
break;
}
}
public function getiplocation($ip){
$ippos = $this->iplocaltion($ip);
$this->ip_range_begin = long2ip($this->getlong(4,$ippos));
$this->ip_range_end = long2ip($this->getlong(4,$this->getlong(3)));
$b = $this->getbyte(1);
switch (ord($b)){
case self::REDIRECT_MODE_1:
$b = $this->getbyte(1,$this->getlong(3));
if(ord($b) == REDIRECT_MODE_2){
$countryoffset = $this->getlong(3);
$this->area = $this->getarea();
$this->country = $this->getstring("",$countryoffset);
}else{
$this->country = $this->getstring($b);
$this->area = $this->getarea();
}
break;

case self::REDIRECT_MODE_2:
$countryoffset = $this->getlong(3);
$this->area = $this->getarea();
$this->country = $this->getstring("",$countryoffset);
break;

default:
$this->country = $this->getstring($b);
$this->area = $this->getarea();
break;
}
}
}
/* */
echo microtime();
echo "\n";
$iploca = new IpLocation;
//$iploca = new IpLocation('QQWry.dat');
echo $iploca->get('wrydat_version');
echo "\n";
echo $iploca->get('ipnumber');
echo "\n";
$iploca->getiplocation('211.44.32.34');
/**/
echo $iploca->get('ip_range_begin');
echo "\n";
echo $iploca->get('ip_range_end');
echo "\n";
echo $iploca->get('country');
echo "\n";
echo $iploca->get('area');

echo "\n";
echo $iploca->get('lastip');
echo "\n";
echo microtime();
echo "\n";
unset($iploca);