path: root/modules-available/dnbd3/inc/dnbd3rpc.inc.php

<?php

class Dnbd3Rpc {

	const ERROR_UNREACHABLE = 1;
	const ERROR_NOT_200 = 2;
	const ERROR_NOT_JSON = 3;

	const QUERY_STATS = 'stats';
	const QUERY_CLIENTS = 'clients';
	const QUERY_IMAGES = 'images';
	const QUERY_SPACE = 'space';
	const QUERY_CONFIG = 'config';
	const QUERY_ALTSERVERS = 'altservers';

	private static function translateServer(string $server): string
	{
		// Special case - local server
		if ($server === '<self>') {
			$server = '127.0.0.1:5003';
		} elseif (($out = Dnbd3Util::matchAddress($server)) !== false) {
			$server = $out['v4'] ?? '[' . $out['v6'] . ']';
			$server .= $out['port'] ?? ':5003';
		}
		return $server;
	}

	/**
	 * Query given DNBD3 server for status information.
	 *
	 * @param string $server server address
	 * @param array $queryOptions Options to query, self::QUERY_*
	 * @return int|array the queried data as an array, or error code (self::ERROR_*) on error
	 */
	public static function query(string $server, array $queryOptions)
	{
		$server = self::translateServer($server);
		$url = 'http://' . $server . '/query?q=version';
		if (!empty($queryOptions)) {
			$url .= '&q=' . implode('&q=', $queryOptions);
		}
		$str = Download::asString($url, 3, $code);
		if ($str === false)
			return self::ERROR_UNREACHABLE;
		if ($code !== 200)
			return self::ERROR_NOT_200;
		$ret = json_decode($str, true);
		if (!is_array($ret))
			return self::ERROR_NOT_JSON;
		return $ret;
	}

	public static function getCacheMap($server, $imgId)
	{
		$server = self::translateServer($server);
		$str = Download::asString('http://' . $server . '/cachemap?id=' . $imgId, 3, $code);
		if ($str === false)
			return self::ERROR_UNREACHABLE;
		if ($code !== 200)
			return self::ERROR_NOT_200;
		return $str;
	}

	/**
	 * Get statistics for multiple servers at once.
	 * @param string[] $servers
	 */
	public static function getStatsMulti(array $servers, array $queryOptions = [], int $timeout = 2): array
	{
		if (empty($servers))
			return [];
		$extra = '';
		if (!empty($queryOptions)) {
			$extra = '&q=' . implode('&q=', $queryOptions);
		}
		$active = [];
		$mh = curl_multi_init();
		curl_multi_setopt($mh, CURLMOPT_MAXCONNECTS, 8);
		curl_multi_setopt($mh, CURLMOPT_MAX_HOST_CONNECTIONS, 2);
		curl_multi_setopt($mh, CURLMOPT_MAX_TOTAL_CONNECTIONS, 8);
		foreach ($servers as $server) {
			$url = 'http://' . self::translateServer($server) . '/query?q=version' . $extra;
			$res = curl_init($url);
			if ($res === false) {
				error_log("curl_init($url) failed");
				continue;
			}
			curl_setopt_array($res, [
				CURLOPT_CONNECTTIMEOUT => $timeout,
				CURLOPT_TIMEOUT => $timeout,
				CURLOPT_FOLLOWLOCATION => 0,
				CURLOPT_ACCEPT_ENCODING => '', // Use everything libcurl supports
				CURLOPT_PROTOCOLS => CURLPROTO_HTTP | CURLPROTO_HTTPS,
				CURLOPT_RETURNTRANSFER => 1,
			]);
			$err = curl_multi_add_handle($mh, $res);
			if ($err !== 0) {
				error_log("curl_multi_add_handle() failed with $err");
				curl_close($res);
			} else {
				$active[(int)$res] = $server;
			}
		}
		// Wait
		$running = 1;
		$result = [];
		$startTime = microtime(true);
		for (;;) {
			$ret = curl_multi_exec($mh, $running);
			while (($info = curl_multi_info_read($mh)) !== false) {
				if ($info['msg'] === CURLMSG_DONE) {
					if (isset($active[(int)$info['handle']])) {
						$server = $active[(int)$info['handle']];
						unset($active[(int)$info['handle']]);
						if ($info['result'] === CURLE_OK) {
							$data = json_decode(curl_multi_getcontent($info['handle']), true);
							if (is_array($data)) {
								$data['ts'] = microtime(true);
								$result[$server] = $data;
							}
						}
					}
					curl_multi_remove_handle($mh, $info['handle']);
					curl_close($info['handle']);
				}
			}
			$delay = ($startTime + $timeout) - microtime(true);
			if ($ret !== CURLM_OK || !$running || $delay <= 0)
				break;
			$sret = curl_multi_select($mh, $delay);
			if ($sret < 0) {
				error_log("curl_multi_select returned $sret");
				break;
			}
		}
		curl_multi_close($mh);
		return $result;
	}

}