How do we make multiple file_get_contents in PHP run faster?

Question

We're building an API that performs repetitive file_get_contents. I have an array of userids and the number of file_get_contents() will be repeated by the number of contents in the array. We will do thousands of requests.

function request($userid) {
    global $access_token;
    $url = 'https://<api-domain>'.$userid.'?access_token='.$access_token;
    $response = file_get_contents($url);
    return json_decode($response);
}

function loopUserIds($arrayUserIds) {
    global $countFollowers;
    $arrayAllUserIds = array();
    foreach ($arrayUserIds as $userid) {
        $followers = request($userid);
        ...
    }
    ...
}

My concern is it takes time to get everything. Since the function will also be called in a loop. Please advise how we can make this (many file_get_contents() requests) run faster?

Answer 1

As @HankyPanky mentioned, you can use curl_multi_exec() to do many concurrent requests at the same time.

Something like this should help:

function fetchAndProcessUrls(array $urls, callable $f) {

    $multi = curl_multi_init();
    $reqs  = [];

    foreach ($urls as $url) {
        $req = curl_init();
        curl_setopt($req, CURLOPT_URL, $url);
        curl_setopt($req, CURLOPT_HEADER, 0);
        curl_multi_add_handle($multi, $req);
        $reqs[] = $req;
    }

    // While we're still active, execute curl
    $active = null;

    // Execute the handles
    do {
        $mrc = curl_multi_exec($multi, $active);
    } while ($mrc == CURLM_CALL_MULTI_PERFORM);

    while ($active && $mrc == CURLM_OK) {
        if (curl_multi_select($multi) != -1) {
            do {
                $mrc = curl_multi_exec($multi, $active);
            } while ($mrc == CURLM_CALL_MULTI_PERFORM);
        }
    }

    // Close the handles
    foreach ($reqs as $req) {
        $f(curl_multi_getcontent($req));
        curl_multi_remove_handle($multi, $req);
    }
    curl_multi_close($multi);
}

You can use it like so:

$urlArray = [ 'http://www.example.com/' , 'http://www.example.com/', ... ];

fetchAndProcessUrls($urlArray, function($requestData) { 

    /* do stuff here */ 

    // e.g.
    $jsonData = json_decode($requestData, 1); //
});