curl多线程类。

<?php
/*
 * Curl 多线程类
 * 使用方法：
 * ========================
    $urls = array("http://baidu.com", "http://dzone.com", "http://google.com");
    $mp = new MultiHttpRequest($urls);
    $mp->start();
 * ========================
 * 当然，如果你喜欢，还可以对此类进行扩展，
 * 比如，如果需要用户登录才能采集的数据怎么办？
 * 只要我们使用 curl 来做伪登录，把 cookie 保存到文件，
 * 每次请求发送有效的 cookie 即可实现伪登录抓去数据！
 */
class MultiHttpRequest {
    public $urls = array();
    public $curlopt_header = 0;
    public $method = "GET";

    function __construct($urls = false) {
        $this->urls = $urls;
    }

    function set_urls($urls) {
        $this->urls = $urls;
        return $this;
     }

     function is_return_header($b) {
         $this->curlopt_header = $b;
         return $this;
     }

     function set_method($m) {
         $this->medthod = strtoupper($m);
         return $this;
     }

     function start() {
         if(!is_array($this->urls) or count($this->urls) == 0){
            return false;
         }
         $curl = $text = array();
         $handle = curl_multi_init();
         foreach($this->urls as $k=>$v){
            $curl[$k] = $this->add_handle($handle, $v);
         }

         $this->exec_handle($handle);
         foreach($this->urls as $k=>$v){
             $text[$k] =  curl_multi_getcontent($curl[$k]);
             curl_multi_remove_handle($handle, $curl[$k]);
         }
         curl_multi_close($handle);

         return $text;
     }

     private function add_handle($handle, $url) {
         $curl = curl_init();
         curl_setopt($curl, CURLOPT_URL, $url);

         curl_setopt($curl, CURLOPT_HEADER, $this->curlopt_header);
         curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
         curl_multi_add_handle($handle, $curl);
         return $curl;
     }

     private function exec_handle($handle) {
         $flag = null;
         do {
            curl_multi_exec($handle, $flag);
         } while ($flag > 0);
     }

     public function get_content($url){
        $ch = curl_init();
        curl_setopt ($ch, CURLOPT_URL, $url);
        curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT,10);
        return curl_exec($ch);
     }
}