ErrorCode WdtUri::process()

in WdtTransferRequest.cpp [129:229]
91 lines of code
20 McCabe index (conditional complexity)

ErrorCode WdtUri::process(const string& url) {
  if (url.size() < WDT_URL_PREFIX.size()) {
    WLOG(ERROR) << "Url doesn't specify wdt protocol";
    return URI_PARSE_ERROR;
  }
  StringPiece urlPiece(url, 0, WDT_URL_PREFIX.size());
  StringPiece wdtPrefix(WDT_URL_PREFIX);
  if (urlPiece != wdtPrefix) {
    WLOG(ERROR) << "Url does not specify wdt protocol " << url;
    return URI_PARSE_ERROR;
  }
  urlPiece = StringPiece(url, WDT_URL_PREFIX.size());
  if (urlPiece.empty()) {
    WLOG(ERROR) << "Empty host name " << url;
    return URI_PARSE_ERROR;
  }
  ErrorCode status = OK;
  // Parse hostname
  if (urlPiece[0] == '[') {
    urlPiece.advance(1);
    size_t hostNameEnd = urlPiece.find(']');
    if (hostNameEnd == string::npos) {
      WLOG(ERROR) << "Didn't find ] for ipv6 address " << url;
      return URI_PARSE_ERROR;
    }
    hostName_.assign(urlPiece.data(), 0, hostNameEnd);
    urlPiece.advance(hostNameEnd + 1);
  } else {
    size_t urlIndex = 0;
    for (; urlIndex < urlPiece.size(); ++urlIndex) {
      if (urlPiece[urlIndex] == ':') {
        break;
      }
      if (urlPiece[urlIndex] == '?') {
        break;
      }
    }
    hostName_.assign(urlPiece.data(), 0, urlIndex);
    urlPiece.advance(urlIndex);
  }

  if (hostName_.empty()) {
    status = URI_PARSE_ERROR;
    WLOG(ERROR) << "Empty hostname " << url;
  }

  if (urlPiece.empty()) {
    return status;
  }
  // TODO: allow for '/' like wdt://[::1]:1234/?num_ports=3
  // parse port number
  if (urlPiece[0] == ':') {
    urlPiece.advance(1);
    size_t paramsIndex = urlPiece.find('?');
    if (paramsIndex == string::npos) {
      paramsIndex = urlPiece.size();
    }
    try {
      string portStr;
      portStr.assign(urlPiece.data(), 0, paramsIndex);
      port_ = folly::to<int32_t>(portStr);
    } catch (std::exception& e) {
      WLOG(ERROR) << "Invalid port, can't be parsed " << url;
      status = URI_PARSE_ERROR;
    }
    urlPiece.advance(paramsIndex);
  }

  if (urlPiece.empty()) {
    return status;
  }

  if (urlPiece[0] != '?') {
    WLOG(ERROR) << "Unexpected delimiter for params " << urlPiece[0];
    return URI_PARSE_ERROR;
  }
  urlPiece.advance(1);
  // parse params
  while (!urlPiece.empty()) {
    StringPiece keyValuePair = urlPiece.split_step('&');
    if (keyValuePair.empty()) {
      // Last key value pair
      keyValuePair = urlPiece;
      urlPiece.advance(urlPiece.size());
    }
    StringPiece key = keyValuePair.split_step('=');
    StringPiece value = keyValuePair;
    if (key.empty()) {
      // Value can be empty but key can't be empty
      WLOG(ERROR) << "Errors parsing params, url = " << url;
      status = URI_PARSE_ERROR;
      break;
    }
    string unescapedValue;
    if (!unescape(unescapedValue, value)) {
      status = URI_PARSE_ERROR;
    }
    queryParams_[key.toString()] = unescapedValue;
  }
  return status;
}