S2OJ/web/app/models/FS.php

<?php

class FS {
	public static function scandir(string $directory, $cfg = []) {
		$cfg += [
		    'exclude_dots' => true
		];
		$entries = scandir($directory);
		if ($cfg['exclude_dots']) {
			$entries = array_filter($entries, fn($name) => $name !== '.' && $name !== '..');
		}
		return $entries;
	}

	public static function scandir_r(string $directory, $cfg = []) {
		foreach (FS::scandir($directory, $cfg) as $name) {
			$cur = "{$directory}/{$name}";
			if (is_dir($cur)) {
				foreach (FS::scandir_r($cur, $cfg) as $sub) {
					yield "{$name}/{$sub}";
				}
			} else {
				yield $name;
			}
		}
	}

	/**
	 * @param int $type lock type. can be either LOCK_SH or LOCK_EX
	*/
	public static function lock_file(string $path, int $type, callable $func) {
		$lock_fp = fopen($path, 'c');
		
		if (!flock($lock_fp, $type | LOCK_NB)) {
			UOJLog::error("lock failed: {$path}");
			return false;
		}
		
		$ret = $func();
		
		flock($lock_fp, LOCK_UN | LOCK_NB);

		return $ret;
	}

	public static function randomAvailableFileName($dir, $suffix = '') {
		do {
			$name = $dir . uojRandString(20) . $suffix;
		} while (file_exists(UOJContext::storagePath().$name));
		return $name;
	}

	public static function randomAvailableTmpFileName() {
		return static::randomAvailableFileName('/tmp/');
	}

	public static function randomAvailableSubmissionFileName() {
		$num = uojRand(1, 10000);
		if (!file_exists(UOJContext::storagePath()."/submission/$num")) {
			system("mkdir ".UOJContext::storagePath()."/submission/$num");
		}
		return static::randomAvailableFileName("/submission/$num/");
	}
}