std::unique_ptr ParseRetryPolicy()

in src/core/ext/filters/client_channel/resolver_result_parsing.cc [94:206]
107 lines of code
30 McCabe index (conditional complexity)

std::unique_ptr<ClientChannelMethodParsedConfig::RetryPolicy> ParseRetryPolicy(
    const Json& json, grpc_error** error) {
  GPR_DEBUG_ASSERT(error != nullptr && *error == GRPC_ERROR_NONE);
  auto retry_policy =
      absl::make_unique<ClientChannelMethodParsedConfig::RetryPolicy>();
  if (json.type() != Json::Type::OBJECT) {
    *error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
        "field:retryPolicy error:should be of type object");
    return nullptr;
  }
  std::vector<grpc_error*> error_list;
  // Parse maxAttempts.
  auto it = json.object_value().find("maxAttempts");
  if (it != json.object_value().end()) {
    if (it->second.type() != Json::Type::NUMBER) {
      error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:maxAttempts error:should be of type number"));
    } else {
      retry_policy->max_attempts =
          gpr_parse_nonnegative_int(it->second.string_value().c_str());
      if (retry_policy->max_attempts <= 1) {
        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
            "field:maxAttempts error:should be at least 2"));
      } else if (retry_policy->max_attempts > MAX_MAX_RETRY_ATTEMPTS) {
        gpr_log(GPR_ERROR,
                "service config: clamped retryPolicy.maxAttempts at %d",
                MAX_MAX_RETRY_ATTEMPTS);
        retry_policy->max_attempts = MAX_MAX_RETRY_ATTEMPTS;
      }
    }
  }
  // Parse initialBackoff.
  it = json.object_value().find("initialBackoff");
  if (it != json.object_value().end()) {
    if (!ParseDuration(it->second, &retry_policy->initial_backoff)) {
      error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:initialBackoff error:Failed to parse"));
    } else if (retry_policy->initial_backoff == 0) {
      error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:initialBackoff error:must be greater than 0"));
    }
  }
  // Parse maxBackoff.
  it = json.object_value().find("maxBackoff");
  if (it != json.object_value().end()) {
    if (!ParseDuration(it->second, &retry_policy->max_backoff)) {
      error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:maxBackoff error:failed to parse"));
    } else if (retry_policy->max_backoff == 0) {
      error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:maxBackoff error:should be greater than 0"));
    }
  }
  // Parse backoffMultiplier.
  it = json.object_value().find("backoffMultiplier");
  if (it != json.object_value().end()) {
    if (it->second.type() != Json::Type::NUMBER) {
      error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:backoffMultiplier error:should be of type number"));
    } else {
      if (sscanf(it->second.string_value().c_str(), "%f",
                 &retry_policy->backoff_multiplier) != 1) {
        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
            "field:backoffMultiplier error:failed to parse"));
      } else if (retry_policy->backoff_multiplier <= 0) {
        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
            "field:backoffMultiplier error:should be greater than 0"));
      }
    }
  }
  // Parse retryableStatusCodes.
  it = json.object_value().find("retryableStatusCodes");
  if (it != json.object_value().end()) {
    if (it->second.type() != Json::Type::ARRAY) {
      error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:retryableStatusCodes error:should be of type array"));
    } else {
      for (const Json& element : it->second.array_value()) {
        if (element.type() != Json::Type::STRING) {
          error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
              "field:retryableStatusCodes error:status codes should be of type "
              "string"));
          continue;
        }
        grpc_status_code status;
        if (!grpc_status_code_from_string(element.string_value().c_str(),
                                          &status)) {
          error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
              "field:retryableStatusCodes error:failed to parse status code"));
          continue;
        }
        retry_policy->retryable_status_codes.Add(status);
      }
      if (retry_policy->retryable_status_codes.Empty()) {
        error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
            "field:retryableStatusCodes error:should be non-empty"));
      };
    }
  }
  // Make sure required fields are set.
  if (error_list.empty()) {
    if (retry_policy->max_attempts == 0 || retry_policy->initial_backoff == 0 ||
        retry_policy->max_backoff == 0 ||
        retry_policy->backoff_multiplier == 0 ||
        retry_policy->retryable_status_codes.Empty()) {
      *error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
          "field:retryPolicy error:Missing required field(s)");
      return nullptr;
    }
  }
  *error = GRPC_ERROR_CREATE_FROM_VECTOR("retryPolicy", &error_list);
  return *error == GRPC_ERROR_NONE ? std::move(retry_policy) : nullptr;
}