Program Listing for File yaml_parser.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2022-2023 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 "../core/common.hpp"

namespace {
bool is_space(unsigned char c) {
  return c == ' ';
}
}  // namespace

template <typename typeT>
struct YAML::convert<std::complex<typeT>> {
  static Node encode(const std::complex<typeT>& data) {
    Node node;
    node =
        std::string{fmt::format("{}{}{}j", data.real(), (data.imag() < 0) ? "" : "+", data.imag())};
    return node;
  }

  static bool decode(const Node& node, std::complex<typeT>& data) {
    if (!node.IsScalar()) {
      HOLOSCAN_LOG_ERROR("complex<T> decode: expected a scalar");
      return false;
    }
    std::string value = node.as<std::string>();

    std::regex complex_reg("\\s*([+-]?\\s?\\d*\\.?\\d+)\\s?([+-]{1}\\s?\\d*\\.?\\d+)[ij]{1}\\s*$");
    std::smatch m;
    if (std::regex_search(value, m, complex_reg)) {
      if (m.size() != 3) {
        HOLOSCAN_LOG_ERROR("unexpected match size: {},  matched: {}", m.size(), m.str(0));
      }
      // extract the real and imaginary components of the number
      std::string real_str = m.str(1);
      std::string imag_str = m.str(2);

      // remove any white space around + or - (necessary for std::stod to work)
      real_str.erase(std::remove_if(real_str.begin(), real_str.end(), is_space), real_str.end());
      imag_str.erase(std::remove_if(imag_str.begin(), imag_str.end(), is_space), imag_str.end());

      // format real and imaginary strings as floating point
      double real = std::stod(real_str);
      double imag = std::stod(imag_str);
      data = std::complex<typeT>(real, imag);
    } else {
      HOLOSCAN_LOG_ERROR("failed to match expected regex for complex<T>");
      return false;
    }
    return true;
  }
};

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 */