protected function compressFile($filepath)
	{
		if (!$this->getBackupFilesystemInstance()->checkFunctionExists('gzencode')) {
			throw new BackupException('The method: "gzencode" isn\'t currently enabled.');
		}

		$compressedFilepath = $this->getCompressedFilepath($filepath);
		$this->getBackupFilesystemInstance()->writeCompressedFile($compressedFilepath, $filepath);
		$this->getBackupFilesystemInstance()->removeFile($filepath);

		return $compressedFilepath;
	}