<?php
namespace Curlroll;
class CurlRoll
{
    /**
     * @var int
     * 并发请求数，设置此值过大，同一时间内如果请求远端主机会很容易被判定为DDos攻击
     */
    private $window_size = 5;
    /**
     * @var float
     * curl_multi_select 处理超时时间.
     */
    private $timeout = 10;
    /**
     * @var array
     * 请求对象 CurlRequest 实例数组
     */
    private $requests = array();
    /**
     * @var array
     * 并发请求map
     */
    private $requestMap = array();
    /**
     * @var string|array
     * callback function,结果处理回调函数.
     */
    private $callback;
    /**
     * @var array
     * HTTP request default options.
     */
    private $options = array(
        CURLOPT_SSL_VERIFYPEER => 0, //不开启https请求
        CURLOPT_RETURNTRANSFER => 1, //请求信息以文件流方式返回
        CURLOPT_CONNECTTIMEOUT => 10, //连接超时时间
        CURLOPT_TIMEOUT => 20, //设置curl执行最大时间
        CURLOPT_FOLLOWLOCATION => 1, //curl允许根据response location的值重定向请求
        CURLOPT_MAXREDIRS => 5, //CURLOPT_FOLLOWLOCATION为真后，此值设定重定向递归最大次数
        CURLOPT_HEADER => 0, //设置为true,请求返回的文件流中就会包含response header
        CURLOPT_AUTOREFERER => true, //当根据Location重定向时，自动设置header中的referer信息
        CURLOPT_ENCODING => "", //HTTP请求头中"Accept-Encoding"的值，为空发送所有支持的编码类型
    );
    /**
     * @var array
     * HTTP Request发送的header信息
     */
    private $headers = array(
        'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
        'Accept-Language: zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3',
        'Connection: close',
        'Cache-Control: max-age=0',
        //'X-FORWARD-FOR:8.8.8.8',      //代理ip地址
        //'CLIENT-IP:3.3.3.3',          //客户端ip，REMOTE_ADDR不为空的情况下，是比较真是ip,不好伪造
    );
    private static $agent = array(
        //google chrome
        'Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.17 Safari/537.36',
        'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.62 Safari/537.36',
        'Mozilla/5.0 (X11; CrOS i686 4319.74.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.57 Safari/537.36',
        'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1468.0 Safari/537.36',
        'Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:25.0) Gecko/20100101 Firefox/25.0',
        //firefox
        'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:25.0) Gecko/20100101 Firefox/25.0',
        'Mozilla/5.0 (Windows NT 6.0; WOW64; rv:24.0) Gecko/20100101 Firefox/24.0',
        'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Firefox/24.0',
        'Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)',
        //ie
        'Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0)',
        'Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)',
        'Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; GTB7.4; InfoPath.2; SV1; .NET CLR 3.3.69573; WOW64; en-US)',
    );
    /**
     * @param int
     * $window_size
     */
    public function __construct($window_size = 5)
    {
        $this->window_size = (int)$window_size ? : 5;
    }
    /**
     * @return void
     */
    public function __destruct()
    {
        unset($this->window_size, $this->callback, $this->options, $this->headers, $this->requests);
    }
    /**
     * @param string $name
     * @return mixed
     */
    public function __get($name)
    {
        return isset($this->{$name}) ? $this->{$name} : null;
    }
    /**
     * @param string $name
     * @param mixed $value
     * @return bool
     */
    public function __set($name, $value)
    {
        // append the base options & headers
        if ($name == "options" || $name == "headers")
        {
            $this->{$name} = $value + $this->{$name};
        } else
        {
            $this->{$name} = $value;
        }
        return true;
    }
    /**
     * Add a request to the request queue
     *
     * @param $url
     * @return bool
     */
    public function add($url)
    {
        $this->requests[] = $this->createRequest($url, 'GET', $this->headers, $this->options);
        return true;
    }
    /**
     * Perform GET request
     *
     * @param string $url
     * @param  $headers 不是key-value数组，http请求request header部分的内容
     * $headers = array(
     * "POST ".$page." HTTP/1.0",
     * "Content-type: text/xml;charset=\"utf-8\"",
     * "Accept: text/xml",
     * "Cache-Control: no-cache",
     * "Pragma: no-cache",
     * "SOAPAction: \"run\"",
     * "Content-length: ".strlen($xml_data),
     * "Authorization: Basic " . base64_encode($credentials)
     * );
     * @param  $options
     * @return bool
     */
    public function get($url, $headers = array(), $options = array())
    {
        $this->requests[] = $this->createRequest($url, "GET", $headers, $options);
        return true;
    }
    /**
     * Perform POST request
     *
     * @param string $url
     * @param  $post_data
     * @param  $headers
     * @param  $options
     * @return bool
     */
    public function post($url, $headers = array(), $options = array(), $post_data)
    {
        $this->requests[] = $this->createRequest($url, "POST", $headers, $options, $post_data);
        return true;
    }
    /**
     * Execute processing
     *
     * @param mixed $callback
     * @return string|null
     */
    public function execute($callback = null)
    {
        $ret = null;
        if ($callback)
        {
            $this->callback = $callback;
        }
        if (count($this->requests) == 1)
        {
            $ret = $this->single_curl();
        } else
        {
            $ret = $this->rolling_curl();
        }
        //clear all request once time
        $this->requests = $this->requestMap = array();
        return $ret;
    }
    /**
     * Performs a single curl request
     *
     * @access private
     * @return string
     */
    private function single_curl()
    {
        $ch = curl_init();
        $request = array_shift($this->requests);
        $options = $this->get_options($request);
        curl_setopt_array($ch, $options);
        $output = curl_exec($ch);
        $info = curl_getinfo($ch);
        if ($this->callback && is_callable($this->callback))
        {
            $callback = $this->callback;
            return call_user_func($callback, $output, $info, $request);
        } else
        {
            return $output;
        }
    }
    /**
     * Performs multiple curl requests
     *
     * @access private
     * @return bool
     */
    private function rolling_curl()
    {
        $n = count($this->requests);
        if ($n < $this->window_size)
        {
            $this->window_size = $n;
        }
        if ($this->window_size < 2)
        {
            return false;
        }
        $master = curl_multi_init();
        // start the first batch of requests
        //注意变量i的作用域不是for循环体内，在后续还是可以使用的
        for($i = 0; $i < $this->window_size; $i++)
        {
            $ch = curl_init();
            $options = $this->get_options($this->requests[$i]);
            curl_setopt_array($ch, $options);
            curl_multi_add_handle($master, $ch);
            $key = (string)$ch;
            $this->requestMap[$key] = $i;
        }
        do
        {
            while (($execrun = curl_multi_exec($master, $running)) == CURLM_CALL_MULTI_PERFORM) ;
            if ($execrun != CURLM_OK)
            {
                break;
            }
            // a request was just completed -- find out which one
            while ($done = curl_multi_info_read($master))
            {
                // get the info and content returned on the request
                $info = curl_getinfo($done['handle']);
                $output = curl_multi_getcontent($done['handle']);
                // send the return values to the callback function.
                $callback = $this->callback;
                if (is_callable($callback))
                {
                    $key = (string)$done['handle'];
                    $request = $this->requests[$this->requestMap[$key]];
                    unset($this->requestMap[$key]);
                    call_user_func($callback, $output, $info, $request);
                }
                // start a new request (it's important to do this before removing the old one)
                $n = count($this->requests);
                if (($i < $n) && isset($this->requests[$i]))
                {
                    $ch = curl_init();
                    $options = $this->get_options($this->requests[$i]);
                    curl_setopt_array($ch, $options);
                    curl_multi_add_handle($master, $ch);
                    // Add to our request Maps
                    $key = (string)$ch;
                    $this->requestMap[$key] = $i;
                    $i++;
                }
                // remove the curl handle that just completed
                curl_multi_remove_handle($master, $done['handle']);
            }
            // Block for data in / output; error handling is done by curl_multi_exec
            if ($running)
            {
                curl_multi_select($master, $this->timeout);
            }
        } while ($running);
        return true;
    }
    /**
     * Helper function to set up a new request by setting the appropriate options
     *
     * @access private
     * @param Request $request
     * @return array
     */
    private function get_options($request)
    {
        $options = $this->__get('options');
        $headers = $this->__get('headers');
        // set the request URL
        $options[CURLOPT_URL] = $request->url;
        // set the request method
        // curl默认就是get,设定post_data,既可认为请求是post请求
        // posting data w/ this request?
        if ($request->post_data)
        {
            $options[CURLOPT_POST] = true;
            $options[CURLOPT_POSTFIELDS] = $request->post_data;
        }
        // append custom options for this specific request
        if ($request->options)
        {
            $options = $options + $request->options;
        }
        // 添加个性header
        if ($request->headers)
        {
            $headers = $headers + $request->headers;
        }
        $options[CURLOPT_HTTPHEADER] = $headers;
        return $options;
    }
    private function createRequest($url, $method, $headers, $options, $data = array())
    {
        $o = new \stdClass();
        $o->url = $url;
        $o->method = $method;
        $o->headers = $headers;
        $o->options = $options;
        $o->post_data = $data;
        if (!isset($options[CURLOPT_USERAGENT]))
        {
            $o->options[CURLOPT_USERAGENT] = self::$agent[array_rand(self::$agent)];
        }
        return $o;
    }
}