static Result parseKey()

in src/fuse/IovTable.cc [28:111]
75 lines of code
21 McCabe index (conditional complexity)

static Result<IovAttrs> parseKey(const char *key) {
  IovAttrs iova;

  std::vector<std::string> fnParts;
  folly::split('.', key, fnParts);

  auto idRes = Uuid::fromHexString(fnParts[0]);
  RETURN_ON_ERROR(idRes);
  iova.id = *idRes;

  for (size_t i = 1; i < fnParts.size(); ++i) {
    auto dec = fnParts[i];
    switch (dec[0]) {
      case 'b': {  // block size
        auto i = atoll(dec.c_str() + 1);
        if (i <= 0) {
          return makeError(StatusCode::kInvalidArg, "invalid block size set in shm key");
        }
        iova.blockSize = (size_t)i;
        break;
      }

      case 'r':
      case 'w': {  // is io ring
        auto i = atoll(dec.c_str() + 1);
        iova.isIoRing = true;
        iova.forRead = dec[0] == 'r';
        iova.ioDepth = i;
        break;
      }

      case 't': {
        if (!iova.iora) {
          iova.iora = IorAttrs{};
        }
        auto i = atoi(dec.c_str() + 1);
        if (i < 0) {
          return makeError(StatusCode::kInvalidArg, "invalid io job check timeout {}", dec.c_str() + 1);
        }
        iova.iora->timeout = Duration(std::chrono::nanoseconds((uint64_t)i * 1000000));
        break;
      }

      case 'f': {
        if (!iova.iora) {
          iova.iora = IorAttrs{};
        }
        char *ep;
        auto i = strtoull(dec.c_str() + 1, &ep, 2);
        if (*ep != 0 || i < 0) {
          return makeError(StatusCode::kInvalidArg, "invalid io exec flags {}", dec.c_str() + 1);
        }
        iova.iora->flags = i;
        break;
      }

      case 'p':  // should be io ring, priority
        if (!iova.iora) {
          iova.iora = IorAttrs{};
        }
        switch (dec.c_str()[1]) {
          case 'l':
            iova.iora->priority = 2;
            break;
          case 'h':
            iova.iora->priority = 0;
            break;
          case 'n':
          case '\0':
            iova.iora->priority = 1;
            break;
          default:
            return makeError(StatusCode::kInvalidArg, "invalid priority set in shm key");
        }
        break;
    }
  }

  if (!iova.isIoRing && iova.iora) {
    return makeError(StatusCode::kInvalidArg, "ioring attrs set for non-ioring");
  }

  return iova;
}