PHP微博客应用中的URL缩短类

php微博客应用中的url缩短类        

在Unix机上的PHP脚本 .class.php可以复用 下面有4个方法用来缩短 加密 解密 DB中的原始URL 并缩短他 结合Apache的rewrite模块进行路由
如传入一个http://index.php/catagory/python-cookbook_3tdedition.php 重写为..index.php/123/512.html
 在Apache模块中可以定义 catagory请求为123路由地址
 因为是用的单例模式的CONN 处理并发请求 测试的时候MySQL 并发命中会很低  

#!usr/local/bin/php
characterMap = array(
			'1','2','3','4','5','6','7','8','9',
			'z','x','c','b','v',
			'f','g','h','j','k','L','m','n',
			'q','w','r','t','y','p','s','d'
		);
		$this->base = sizeof($this->characterMap);
	}

	public static function getInstance(){
		static $instance = null;

		if($instance === null){
			$instance = new UrlShortener();
		}
		return $instance;
	}

	public function shorten($conn,$url){
		$escapedUrl = mysql_escape_string($url);

		$res = mysql_query("select 'id' from urls where 'url' like $escapedUrl",$conn);
		$row = mysql_fetch_row($res);
		mysql_free_result($res);

		//如果有 就进行编码 然后重写进入数据库
		if($row)
			return $this->encode($row[0]+self::OFFSET);
		//如果没有 就先编码后插入
		$res = mysql_query("
			insert into 'urls'('url') values('$escapedUrl')
			",$conn);
		return $this->encode(mysql_insert_id($conn)+self::OFFSET);
	}

	public function encode($val){

		#递归对每一个URL中的字符进行解码
		#@return 解码以后的字符串Url 
		$val += 512;
		if($val < $this->base){
			return $this->characterMap[ $val ];
		}else{
			return $this->encode(floor( $val/$this->base)).
				$this->characterMap[ $val % $this->base];
		}
	}

	public function decode($val){
		$decodeMap = array_flip($this->characterMap);#翻转字典
		$parts = array_reverse(str_split( $val ));

		$index = 0;
		$i = 0;
		foreach($parts as $part){
			$index += $decodeMap[$part] * pow($this->base,$i++);	
		}
		return $index-512;
	}

	public function expand($conn,$index){
		$id = $this->decode($index)-self::OFFSET;
		$res = mysql_query('
			select "url" from "urls" where 'id' = $id
			',$conn);
		$value = (($row = mysql_fetch_row( $res)))?$row[0]:null;
		mysql_free_result($res);
		return $value;
	}
}#end class
?>

2. [文件] test4Url.php

#!/usr/local/bin/php

expand(getDb(),$index).'\n';
}

function getDb(){
	static $db = null;
	if(!$db||!mysql_ping($db){
		$db = mysql_connect('localhost','user','password');
		mysql_select_db("test");
	}
	return $db;
}

?>

 以上就是PHP微博客应用中的URL缩短类 的内容，更多相关内容请关注PHP中文网（www.php.cn）！

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