Rotate public listed proxies per each request in PHP.

ScrapingProxyProvider.php

<?php

/**
 * A class which provide public listing proxies rotated when client request.
 */

Class ScrapingProxyProvider 
{
    // Proxies available.
    private $proxyDatas = array();

    // Currently used proxy.
    private $proxyData = null;

    // Maximum count client can use per proxy.
    public $limitUsageCount = 5;

    // Current proxy used count by client.
    private $usedCount = 0;


    /**
     * Return proxy data list remotely, currently we fetch from 'https://proxy.l337.tech'
     * with big thanks.
     */
    private function getRemoteProxies() 
    {
        $proxyDatas = array();

        $content = file_get_contents("https://proxy.l337.tech/txt");
        $rawProxies = explode("\n", $content);

        foreach ($rawProxies as $rawProxy) {
            $rawProxy = explode(":", $rawProxy);
            if (count($rawProxy) != 2) {
                continue;
            }

            $proxyData = array();
            $proxyData["ip"] = $rawProxy[0];
            $proxyData["port"] = $rawProxy[1];

            $proxyDatas[] = $proxyData;
        }

        return $proxyDatas;
    }

    /**
     * Discurd 'proxyData' which is currently used, to trigger
     * force proxy rotation.
     */
    public function discardCurrent() 
    {
        $this->proxyData = null;
    }

    /**
     * Return proxy data which has 'ip' with 'port' separatedly.
     * Each time when client calll, roatte proxy if needed.
     */
    public function fetchProxyData()
    {
        // Get proxies remotely if proxies get out of stocks or no proxies exists.
        if (!$this->proxyDatas || count($this->proxyDatas) == 0) {
            $proxies = $this->getRemoteProxies();

            $this->proxyDatas = $proxies;
        }

        // Rotate proxy.
        if (!$this->proxyData || $this->limitUsageCount <= $this->usedCount){
            $nextProxyData = array_shift($this->proxyDatas);

            $this->usedCount = 0;
            $this->proxyData = $nextProxyData;
        }

        $this->usedCount++;

        return $this->proxyData;
    }
}


/**
 * Example following to give example how we use handle.
 * When the ip banned, recommended to call 'discardCurrent' to rotate forcely.
 */
$proxyProvider = new ScrapingProxyProvider();
$proxyProvider->limitUsageCount = 5;

$url = "https://example.com";
$requestCount = 30;

for ($i = 0; $i < $requestCount; $i++) {
    $proxyData = $proxyProvider->fetchProxyData();

    $ch = curl_init($url);
    $proxy = "{$proxyData["ip"]}:{$proxyData["port"]}";

    curl_setopt_array($ch, array(
        CURLOPT_PROXY => $proxy,
        CURLOPT_HEADER => true,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_FOLLOWLOCATION => true,
    ));

    $content = curl_exec($ch);

    $status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($status != 200) {
        print(" Used proxy could be banned, discard current proxy to get next one.");
        $proxyProvider->discardCurrent();
    }

    print("{$proxy} => ". $status. PHP_EOL);
}