StrawPoll Proxy Voter

class.StrawPoll.php

<?php
set_time_limit(0);
class StrawPoll {
	public function __construct() {
	}

	public function vote($id, array $votes, $amount = 10, $proxyList = null, $timeout = 5, $showErrors = true) {
		$mh = curl_multi_init();
		$chs = array();
		if(is_file($proxyList)) {
			$parts = pathinfo($proxyList);
			$json = false;
			if($parts['extension'] == 'json') {
				$proxies = json_decode(file_get_contents($proxyList), true);
				if($proxies) {
					$json = true;
				} else {
					return 'Malformed JSON in ' . $proxyList;
				}
			} else {
				$proxies = file($proxyList);
			}
		}
		$post = array(
			'id' => $id,
			'votes' => $votes
		);
		$post = http_build_query($post);
		$headers = array(
			'Origin: http://strawpoll.me',
			'If-None-Match: 6bbfd',
			'X-Requested-With: XMLHttpRequest'
		);
		$loop = false;
		if($amount == -1) {
			$loop = true;
			$amount = 25;
		}
		if(isset($proxies)) {
			$amount = count($proxies);
		}
		$used = array();
		for($i = 0; $i < $amount; $i++) {
			$ch = $this->makeCurl('http://strawpoll.me/ajax/vote');
			$chs[] = $ch;
			if(isset($proxies)) {
				if(count($proxies) < 1) {
					if($showErrors) {
						echo 'Out of proxies :(' . PHP_EOL;
					}
					break;
				}
				$key = array_rand($proxies);
				$proxy = $proxies[$key];
				unset($proxies[$key]);
				$proxyType = CURLPROXY_HTTP;
				if(!$json) {
					$proxy = trim($proxy);
					$parts = explode(':', $proxy);
					if(isset($parts[0], $parts[1])) {
						$proxyIP = $parts[0];
						$proxyPort = $parts[1];
					} else {
						$i--;
						continue;
					}
					if(isset($parts[2])) {
						$proxyType = strtoupper($proxyType) == 'SOCKS5' ? CURLPROXY_SOCKS5 : CURLPROXY_HTTP;
					}
				} else if($json && isset($proxy['ip'], $proxy['port'])) {
					$proxyIP = $proxy['ip'];
					$proxyPort = $proxy['port'];
					if(isset($proxy['type'])) {
						$proxyType = strtoupper($proxy['type']) == 'SOCKS5' ? CURLPROXY_SOCKS5 : CURLPROXY_HTTP;
					}
				}
				if(isset($used[$proxyIP])) {
					$i--;
					continue;
				}
				$used[$proxyIP] = true;
				if(!filter_var($proxyIP, FILTER_VALIDATE_IP,
										 FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)
				   || (!ctype_digit($proxyPort) || ($proxyPort < 0 || $proxyPort > 65535))) {
					$i--;
					continue;
				}
				curl_setopt_array($ch, array(
					CURLOPT_PROXY => $proxyIP . ':' . $proxyPort,
					CURLOPT_PROXYTYPE => $proxyType
				));
			}
			curl_setopt_array($ch, array(
				CURLOPT_POSTFIELDS => $post,
				CURLOPT_POST => true,
				CURLOPT_HTTPHEADER => $headers,
				CURLOPT_REFERER => 'http://strawpoll.me/' . $id,
				CURLOPT_USERAGENT => 'Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36',
				CURLOPT_TIMEOUT => $timeout
			));
			curl_multi_add_handle($mh, $ch);
		}
		$running = null;
		$votes = 0;
		$j = 0;
		$results = array();
		do {
			while(($exec = curl_multi_exec($mh, $running)) == CURLM_CALL_MULTI_PERFORM);
			if($exec != CURLM_OK) {
				break;
			}
			while($ch = curl_multi_info_read($mh)) {
				$j++;
				$ch = $ch['handle'];
				$error = curl_error($ch);
				if(!$error) {
					$resp = curl_multi_getcontent($ch);
					$out = json_decode($resp, true);
					if(!isset($out['success'])) {
						if($showErrors) {
							echo 'Didn\'t vote. Invalid response.' . PHP_EOL;
							var_dump($resp);
						}
					} else {
						if($out['success'] == true) {
							$votes++;
							echo '[' . $votes . '] Voted' . PHP_EOL;
						}
					}
					$results[] = $out;
				} else {
					$results[] = $error;
					if($showErrors) {
						echo $error . PHP_EOL;
					}
				}
				curl_multi_remove_handle($mh, $ch);
				curl_close($ch);				
			}
		} while($running);
		curl_multi_close($mh);
		if($loop) {
			$this->vote($id, $votes, $amount, $proxyList, $timeout);
			return array('results' => $results, 'votes' => $votes);
		}
		return array('results' => $results, 'votes' => $votes, 'total' => $amount);
	}

	public function makeCurl($url) {
		$cookie = dirname(__FILE__) . '/strawpoll.txt';
		$ch = curl_init($url);
		curl_setopt_array($ch, array(
			CURLOPT_FOLLOWLOCATION => true,
			CURLOPT_RETURNTRANSFER => true,
			CURLOPT_COOKIEFILE => $cookie,
			CURLOPT_COOKIEJAR => $cookie
		));
		return $ch;
	}
}

$sp = new StrawPoll();
$votes = $sp->vote(1559802, array(1), 5000, 'proxies.txt', 30, false);
echo 'Successfully voted ' . $votes['votes'] . '/' . $votes['total'] . ' time(s)';

How does this work