curl并发下载图片实例

Question

原文：http://blog.ja168.net/muti-thread-download-760.html  /**
     * 远程图片并行下载
     *
     * 确保服务器配置有curl
     *
     * @author blog.ja168.net
     * @param  string $url
     * @param  string $save_path
     * @return void
     */
    function graber_remote_image($url, $save_path="./") {
        set_time_limit(0);
        if(! in_array('curl', get_loaded_extensions())) {
            die("curl not support !");
        }
        $ch = curl_init();
        curl_setopt_array($ch, array(
            CURLOPT_URL            => $url,
            CURLOPT_CONNECTTIMEOUT => 30,
            CURLOPT_REFERER        => !empty($_SERVER["HTTP_REFERER"]) ? $_SERVER["HTTP_REFERER"] : "",
            CURLOPT_RETURNTRANSFER => 1,
            CURLOPT_FOLLOWLOCATION => 1,
            CURLOPT_USERAGENT      => $_SERVER['HTTP_USER_AGENT']
        ));
        $message =  curl_exec($ch);
        if(preg_match_all("/(http:\/\/|www\.)[^ \"']+/i", $message, $matches)) {
            $images_links = array();
            foreach ($matches[0] as $item) {
                $suffix = pathinfo($item, PATHINFO_EXTENSION);
                if(in_array(strtolower($suffix), array('gif', 'png', 'jpg'))) {
                    array_push($images_links, $item);
                }
            }
        }
        if(empty($images_links)) {
            die('get nothing image inforation.');
        }
        $images_links = array_unique($images_links);
        if(! @mkdir($save_path, 0777, true)) {
            die('save path creaed failed !');
        }
        // Download images
        $mh     = curl_multi_init();
        $handle = array();
        foreach ($images_links as $k=>$item_url) {
            $handle[$k]['thread']   = curl_copy_handle($ch);
            $handle[$k]['filename']  = pathinfo($item_url, PATHINFO_BASENAME);
 
            curl_setopt($handle[$k]['thread'], CURLOPT_URL, $item_url);
            curl_multi_add_handle($mh, $handle[$k]['thread']);
            //******************************************
            // cpu load 100% problem                   *
            //******************************************
//          $running = null;
//          do {
//              curl_multi_exec($mh, $running);
//              //usleep(1000000);
//          } while ($running > 0);
 
            //******************************************
            // work well
            //******************************************
            do {
                $status = curl_multi_exec($mh, $active);
                $info = curl_multi_info_read($mh);
                if (false !== $info) {
                    var_dump($info);
                }
            } while ($status === CURLM_CALL_MULTI_PERFORM || $active);
        }
 
        foreach ($handle as $item) {
 
            $return = curl_multi_getcontent($item['thread']);
            curl_multi_remove_handle($mh, $item['thread']);
            file_put_contents($save_path . '/' . $item['filename'] , $return);
        }
        curl_multi_close($mh);
        return true;
    }
 
    // demon 测试下载新浪首页全部图片
    function microtime_float() {
        list($usec, $sec) = explode(" ", microtime());
        return ((float)$usec + (float)$sec);
    }
    $time_start = microtime_float();
    graber_remote_image("http://www.sina.com.cn", "/home/www/admin/img");
    $time_end = microtime_float();
    $time = $time_end - $time_start;
 
    echo "Time: $time seconds<br />";
    echo "Total:" . count($images_links) . " download.";curl