PHP implements non blocking (concurrent) request mode through native curl

Antecedents feed

In actual development , There are often scenarios where a program needs to perform multiple operations at the same time , If the request method is inappropriate in such scenarios , In the later logic, the increase of accumulated data will affect the response efficiency of the program , Generally, non blocking mode can be used in this scenario , Here, it can also be understood as concurrency mode .

What are blocking and non blocking

Blocking ： It means that the application executes IO Operation needs to be completed completely before returning to user space

Non blocking ： It means that the application executes IO A status value is returned to the user immediately after the operation is called , No need to wait IO Operation complete .

How to implement non blocking mode

PHP There are many ways to implement non blocking mode , For example PHP-FPM Use function in mode fastcgi_finish_request() perhaps fsockopen() And so on , Native will be used here CURL To implement the non blocking mode of the request .

Realization way

The main implementation core is actually the use of CURL Medium curl_multi_* Function to send an asynchronous request

• Create class file MultiHttpRequest.php, The code implementation is as follows

<?php

class MultiHttpRequest
{
    
    public $requests = [];

    /** *  Set the request url * * @param $requests * @return $this */
    public function setRequests($requests) {
    
        $this->requests = $requests;
        return $this;
    }

    /** *  Send a request  * * @return array|false */
    public function request()
    {
    
        if(!is_array($this->requests) or count($this->requests) == 0){
    
            return false;
        }

        $curl   = $response = [];
        $handle = curl_multi_init();
        foreach($this->requests as $k => $v){
    
            $url      = isset($v['url']) ? $v['url'] : '';
            $postData = isset($v['postData']) ? $v['postData'] : [];
            $header   = isset($v['header']) ? $v['header'] : [];
            $timeOut  = isset($v['timeOut']) ? $v['timeOut'] : 1;
            $proxy    = isset($v['proxy']) ? $v['proxy'] : '';
            $curl[$k] = $this->buildCurlObject($url, $postData, $header, $timeOut, $proxy);

            curl_multi_add_handle($handle, $curl[$k]);
        }

        $this->execHandle($handle);
        foreach ($this->requests as $key => $val){
    
            $response[$key] =  curl_multi_getcontent($curl[$key]);

            curl_multi_remove_handle($handle, $curl[$key]);
            curl_close($curl[$key]);
        }

        curl_multi_close($handle);

        return $response;
    }

    /** *  Construct request  * * @param $url * @param $postData * @param $header * @param $timeOut * @param $proxy * @return false|resource */
    private function buildCurlObject($url, $postData, $header, $timeOut, $proxy) {
    

        $curl = curl_init();

        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_HEADER, false);
        curl_setopt($curl, CURLOPT_TIMEOUT, (int)$timeOut);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
        curl_setopt($curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);

        //  Configure agent 
        if (!empty($proxy))
            curl_setopt($curl, CURLOPT_PROXY, $proxy);

        //  Merge request header information 
        if(!empty($header))
            curl_setopt($curl, CURLOPT_HTTPHEADER, $header);

        //  Whether it is post request 
        if(!empty($postData) && is_array($postData)){
    
            curl_setopt($curl, CURLOPT_POST, true);
            curl_setopt($curl, CURLOPT_POSTFIELDS,  http_build_query($postData));
        }

        //  Whether it is https
        if(stripos($url,'https') === 0){
    
            curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        }

        return $curl;
    }

    /** *  Execute batch handle  * * @param $handle * @return void */
    private function execHandle($handle)
    {
    
        $active = true;
        $mrc = CURLM_OK;
        while ($active && $mrc == CURLM_OK) {
    
            do {
    
                $mrc = curl_multi_exec($handle, $active);
            } while ($mrc == CURLM_CALL_MULTI_PERFORM);

            if (curl_multi_select($handle) == -1) {
    
                usleep(100);
            }
        }
    }
}

• Calling procedure , Non blocking request

<?php

$response = new MultiHttpRequest();

$url = [
	['url' => 'https://www.baidu.com',
	'postData' =>['aaa'=>1],
	'header' => [
		"Content-Type:application/Json",
		"X-Requested-With:XMLhttpRequest"
	],
	'timeOut' => 2,
	'proxy' => '127.0.0.1'
	],
	['url' => 'https://www.baidu.com'],
	['url' => 'https://www.baidu.com'],
];

$response = $this->setRequests($url)->request();

var_dump($response);