Program Listing for File yaml_parser.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2022-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#ifndef HOLOSCAN_UTILS_YAML_PARSER_HPP
#define HOLOSCAN_UTILS_YAML_PARSER_HPP

#include <yaml-cpp/yaml.h>

#include <iostream>
#include <memory>
#include <regex>
#include <sstream>
#include <string>
#include <utility>
#include <vector>

#include "common/yaml_parser.hpp" // YAML parser for std::complex types
#include "../core/common.hpp"

// Note: GXF provides a custom YAML parser for std::complex types.
//
// Examples of valid strings are:
// "1.0 + 2.5j"
// "-1.0 - 3i"
// "1+3.3j"
//
// There may be 0 or 1 space between a + or - sign and the digits.
// Either "i" or "j" must appear immediately after the second number.

namespace holoscan {

template <typename typeT, typename valueT = void>
struct YAMLNodeParser;

template <typename typeT>
struct YAMLNodeParser<typeT> {
  static typeT parse(const YAML::Node& node) {
    try {
      return node.as<typeT>();
    } catch (...) {
      std::stringstream ss;
      ss << node;
      HOLOSCAN_LOG_ERROR("Unable to parse YAML node: '{}'", ss.str());
      return typeT();
    }
  }
};

template <>
struct YAMLNodeParser<int8_t> {
  static uint8_t parse(const YAML::Node& node) {
    try {
      return static_cast<int8_t>(node.as<int32_t>());
    } catch (...) {
      std::stringstream ss;
      ss << node;
      HOLOSCAN_LOG_ERROR("Unable to parse YAML node: '{}'", ss.str());
      return 0;
    }
  }
};

template <>
struct YAMLNodeParser<uint8_t> {
  static uint8_t parse(const YAML::Node& node) {
    try {
      return static_cast<uint8_t>(node.as<uint32_t>());
    } catch (...) {
      std::stringstream ss;
      ss << node;
      HOLOSCAN_LOG_ERROR("Unable to parse YAML node: '{}'", ss.str());
      return 0;
    }
  }
};

template <typename typeT>
struct YAMLNodeParser<std::complex<typeT>> {
  static std::complex<typeT> parse(const YAML::Node& node) {
    try {
      return static_cast<std::complex<typeT>>(node.as<std::complex<typeT>>());
    } catch (...) {
      std::stringstream ss;
      ss << node;
      HOLOSCAN_LOG_ERROR("Unable to parse YAML node: '{}'", ss.str());
      return 0;
    }
  }
};

template <typename typeT>
struct YAMLNodeParser<std::vector<typeT>> {
  static std::vector<typeT> parse(const YAML::Node& node) {
    if (!node.IsSequence()) {
      std::stringstream ss;
      ss << node;
      HOLOSCAN_LOG_ERROR("Unable to parse YAML node: '{}'. It is not a sequence.", ss.str());
      return std::vector<typeT>();
    }
    std::vector<typeT> result(node.size());
    for (size_t i = 0; i < node.size(); i++) {
      const auto value = YAMLNodeParser<typeT>::parse(node[i]);
      // TODO: check if value is valid
      result[i] = std::move(value);
    }
    return result;
  }
};

template <typename typeT, std::size_t N>
struct YAMLNodeParser<std::array<typeT, N>> {
  static std::array<typeT, N> parse(const YAML::Node& node) {
    if (!node.IsSequence()) {
      std::stringstream ss;
      ss << node;
      HOLOSCAN_LOG_ERROR("Unable to parse YAML node: '{}'. It is not a sequence.", ss.str());
      return std::array<typeT, N>();
    }
    if (node.size() != N) {
      std::stringstream ss;
      ss << node;
      HOLOSCAN_LOG_ERROR(
          "Unable to parse YAML node: '{}'. It is not a sequence of size {}.", ss.str(), N);
      return std::array<typeT, N>();
    }
    std::array<typeT, N> result;
    for (size_t i = 0; i < node.size(); i++) {
      const auto value = YAMLNodeParser<typeT>::parse(node[i]);
      // TODO: check if value is valid
      result[i] = std::move(value);
    }
    return result;
  }
};

// Skip std::shared_ptr<Resource> and std::shared_ptr<Condition>
template <typename typeT>
struct YAMLNodeParser<std::shared_ptr<typeT>> {
  static std::shared_ptr<typeT> parse(const YAML::Node&) { return {}; }
};

// Skip IOSpec*
template <>
struct YAMLNodeParser<IOSpec*> {
  static IOSpec* parse(const YAML::Node&) { return nullptr; }
};

// Skip std::vector<IOSpec*>
template <>
struct YAMLNodeParser<std::vector<IOSpec*>> {
  static std::vector<IOSpec*> parse(const YAML::Node&) { return {}; }
};

}  // namespace holoscan

#endif/* HOLOSCAN_UTILS_YAML_PARSER_HPP */