control/json/utils/modifier.cpp - openbmc/phosphor-fan-presence - Gitiles

 /**
  * Copyright © 2021 IBM Corporation
  *
  * 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.
  */

 #include "modifier.hpp"

 #include "json/config_base.hpp"
 #include "json/manager.hpp"

 #include <phosphor-logging/log.hpp>

 #include <format>

 using namespace phosphor::logging;

 namespace phosphor::fan::control::json
 {

 /**
  * @brief Variant visitor to return a value of the template type specified.
  */
 template <typename T>
 struct ToTypeVisitor
 {
     template <typename U>
     T operator()(const U& t) const
     {
         if constexpr (std::is_arithmetic_v<U> && std::is_arithmetic_v<T>)
         {
             return static_cast<T>(t);
         }
         throw std::invalid_argument(
             "Non arithmetic type used in ToTypeVisitor");
     }
 };

 /**
  * @brief Return a default value to use when the argument passed
  *        to LessThanOperator is out of range.
  */
 PropertyVariantType
     getDefaultValue(const PropertyVariantType& val,
                     const std::optional<PropertyVariantType>& defaultValue)
 {
     // When a default value is given, return that
     if (defaultValue)
     {
         return *defaultValue;
     }

     if (std::holds_alternative<bool>(val))
     {
         return false;
     }
     else if (std::holds_alternative<std::string>(val))
     {
         return std::string{};
     }
     else if (std::holds_alternative<double>(val))
     {
         return std::numeric_limits<double>::quiet_NaN();
     }
     else if (std::holds_alternative<int32_t>(val))
     {
         return std::numeric_limits<int32_t>::quiet_NaN();
     }
     else if (std::holds_alternative<int64_t>(val))
     {
         return std::numeric_limits<int64_t>::quiet_NaN();
     }

     throw std::runtime_error(
         "Invalid variant type when determining default value");
 }

 /**
  * @brief Implements the minus operator to subtract two values.
  *
  * With strings values, A - B removes all occurrences of B in A.
  * Throws if the type is a bool.
  */
 struct MinusOperator : public Modifier::BaseOperator
 {
     explicit MinusOperator(const json& jsonObj) :
         arg(ConfigBase::getJsonValue(jsonObj["value"]))
     {}

     PropertyVariantType operator()(double val) override
     {
         return val - std::visit(ToTypeVisitor<double>(), arg);
     }

     PropertyVariantType operator()(int32_t val) override
     {
         return val - std::visit(ToTypeVisitor<int32_t>(), arg);
     }

     PropertyVariantType operator()(int64_t val) override
     {
         return val - std::visit(ToTypeVisitor<int64_t>(), arg);
     }

     PropertyVariantType operator()(const std::string& val) override
     {
         // Remove all occurrences of arg from val.
         auto value = val;
         auto toRemove = std::get<std::string>(arg);
         size_t pos;
         while ((pos = value.find(toRemove)) != std::string::npos)
         {
             value.erase(pos, toRemove.size());
         }

         return value;
     }

     PropertyVariantType operator()(bool) override
     {
         throw std::runtime_error{
             "Bool not allowed as a 'minus' modifier value"};
     }

     PropertyVariantType arg;
 };

 /**
  * @brief Implements an operator to return a value specified in the JSON that is
  * chosen based on if the value passed into the operator is less than the lowest
  * arg_value it is true for or the given `default_value` if not found to be less
  * than any entries.
  *
  * "modifier": {
  *  "operator": "less_than",
  *  "default_value": 1000, // OPTIONAL
  *  "value": [
  *    {
  *      "arg_value": 30, // if value is less than 30
  *      "parameter_value": 300  // then return 300
  *    },
  *    {
  *      "arg_value": 40, // else if value is less than 40
  *      "parameter_value": 400 // then return 400
  *    },
  *   ]
  *  }
  *
  * If the value passed in is higher than the highest arg_value, it returns a
  * default value this is the `default_value` given or based on the data type of
  * parameter_value.
  */
 struct LessThanOperator : public Modifier::BaseOperator
 {
     explicit LessThanOperator(const json& jsonObj)
     {
         const auto& valueArray = jsonObj["value"];
         if (!valueArray.is_array())
         {
             log<level::ERR>(
                 std::format("Invalid JSON data for less_than config: {}",
                             valueArray.dump())
                     .c_str());
             throw std::invalid_argument("Invalid modifier JSON");
         }

         for (const auto& valueEntry : valueArray)
         {
             if (!valueEntry.contains("arg_value") ||
                 !valueEntry.contains("parameter_value"))
             {
                 log<level::ERR>(
                     std::format("Missing arg_value or parameter_value keys "
                                 "in less_than config: {}",
                                 valueArray.dump())
                         .c_str());
                 throw std::invalid_argument("Invalid modifier JSON");
             }

             auto argVal = ConfigBase::getJsonValue(valueEntry.at("arg_value"));

             if (std::holds_alternative<bool>(argVal))
             {
                 log<level::ERR>(
                     std::format(
                         "Invalid data type in arg_value key in modifier JSON "
                         "config: {}",
                         valueArray.dump())
                         .c_str());
                 throw std::invalid_argument("Invalid modifier JSON");
             }

             auto paramVal =
                 ConfigBase::getJsonValue(valueEntry.at("parameter_value"));

             rangeValues.emplace_back(argVal, paramVal);
         }

         if (rangeValues.empty())
         {
             log<level::ERR>(std::format("No valid range values found in "
                                         "modifier json: {}",
                                         valueArray.dump())
                                 .c_str());
             throw std::invalid_argument("Invalid modifier JSON");
         }

         if (jsonObj.contains("default_value"))
         {
             defaultValue = ConfigBase::getJsonValue(jsonObj["default_value"]);
         }
     }

     PropertyVariantType operator()(double val) override
     {
         for (const auto& rangeValue : rangeValues)
         {
             if (val < std::visit(ToTypeVisitor<double>(), rangeValue.first))
             {
                 return rangeValue.second;
             }
         }
         // Return a default value based on last entry type
         return getDefaultValue(rangeValues.back().second, defaultValue);
     }

     PropertyVariantType operator()(int32_t val) override
     {
         for (const auto& rangeValue : rangeValues)
         {
             if (val < std::visit(ToTypeVisitor<int32_t>(), rangeValue.first))
             {
                 return rangeValue.second;
             }
         }
         return getDefaultValue(rangeValues.back().second, defaultValue);
     }

     PropertyVariantType operator()(int64_t val) override
     {
         for (const auto& rangeValue : rangeValues)
         {
             if (val < std::visit(ToTypeVisitor<int64_t>(), rangeValue.first))
             {
                 return rangeValue.second;
             }
         }
         return getDefaultValue(rangeValues.back().second, defaultValue);
     }

     PropertyVariantType operator()(const std::string& val) override
     {
         for (const auto& rangeValue : rangeValues)
         {
             if (val <
                 std::visit(ToTypeVisitor<std::string>(), rangeValue.first))
             {
                 return rangeValue.second;
             }
         }
         return getDefaultValue(rangeValues.back().second, defaultValue);
     }

     PropertyVariantType operator()(bool) override
     {
         throw std::runtime_error{
             "Bool not allowed as a 'less_than' modifier value"};
     }

     std::vector<std::pair<PropertyVariantType, PropertyVariantType>>
         rangeValues;
     std::optional<PropertyVariantType> defaultValue;
 };

 Modifier::Modifier(const json& jsonObj)
 {
     setOperator(jsonObj);
 }

 void Modifier::setOperator(const json& jsonObj)
 {
     if (!jsonObj.contains("operator") || !jsonObj.contains("value"))
     {
         log<level::ERR>(
             std::format(
                 "Modifier entry in JSON missing 'operator' or 'value': {}",
                 jsonObj.dump())
                 .c_str());
         throw std::invalid_argument("Invalid modifier JSON");
     }

     auto op = jsonObj["operator"].get<std::string>();

     if (op == "minus")
     {
         _operator = std::make_unique<MinusOperator>(jsonObj);
     }
     else if (op == "less_than")
     {
         _operator = std::make_unique<LessThanOperator>(jsonObj);
     }
     else
     {
         log<level::ERR>(std::format("Invalid operator in the modifier JSON: {}",
                                     jsonObj.dump())
                             .c_str());
         throw std::invalid_argument("Invalid operator in the modifier JSON");
     }
 }

 PropertyVariantType Modifier::doOp(const PropertyVariantType& val)
 {
     return std::visit(*_operator, val);
 }

 } // namespace phosphor::fan::control::json
	/**
	* Copyright © 2021 IBM Corporation
	*
	* 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.
	*/

	#include "modifier.hpp"

	#include "json/config_base.hpp"
	#include "json/manager.hpp"

	#include <phosphor-logging/log.hpp>

	#include <format>

	using namespace phosphor::logging;

	namespace phosphor::fan::control::json
	{

	/**
	* @brief Variant visitor to return a value of the template type specified.
	*/
	template <typename T>
	struct ToTypeVisitor
	{
	template <typename U>
	T operator()(const U& t) const
	{
	if constexpr (std::is_arithmetic_v<U> && std::is_arithmetic_v<T>)
	{
	return static_cast<T>(t);
	}
	throw std::invalid_argument(
	"Non arithmetic type used in ToTypeVisitor");
	}
	};

	/**
	* @brief Return a default value to use when the argument passed
	* to LessThanOperator is out of range.
	*/
	PropertyVariantType
	getDefaultValue(const PropertyVariantType& val,
	const std::optional<PropertyVariantType>& defaultValue)
	{
	// When a default value is given, return that
	if (defaultValue)
	{
	return *defaultValue;
	}

	if (std::holds_alternative<bool>(val))
	{
	return false;
	}
	else if (std::holds_alternative<std::string>(val))
	{
	return std::string{};
	}
	else if (std::holds_alternative<double>(val))
	{
	return std::numeric_limits<double>::quiet_NaN();
	}
	else if (std::holds_alternative<int32_t>(val))
	{
	return std::numeric_limits<int32_t>::quiet_NaN();
	}
	else if (std::holds_alternative<int64_t>(val))
	{
	return std::numeric_limits<int64_t>::quiet_NaN();
	}

	throw std::runtime_error(
	"Invalid variant type when determining default value");
	}

	/**
	* @brief Implements the minus operator to subtract two values.
	*
	* With strings values, A - B removes all occurrences of B in A.
	* Throws if the type is a bool.
	*/
	struct MinusOperator : public Modifier::BaseOperator
	{
	explicit MinusOperator(const json& jsonObj) :
	arg(ConfigBase::getJsonValue(jsonObj["value"]))
	{}

	PropertyVariantType operator()(double val) override
	{
	return val - std::visit(ToTypeVisitor<double>(), arg);
	}

	PropertyVariantType operator()(int32_t val) override
	{
	return val - std::visit(ToTypeVisitor<int32_t>(), arg);
	}

	PropertyVariantType operator()(int64_t val) override
	{
	return val - std::visit(ToTypeVisitor<int64_t>(), arg);
	}

	PropertyVariantType operator()(const std::string& val) override
	{
	// Remove all occurrences of arg from val.
	auto value = val;
	auto toRemove = std::get<std::string>(arg);
	size_t pos;
	while ((pos = value.find(toRemove)) != std::string::npos)
	{
	value.erase(pos, toRemove.size());
	}

	return value;
	}

	PropertyVariantType operator()(bool) override
	{
	throw std::runtime_error{
	"Bool not allowed as a 'minus' modifier value"};
	}

	PropertyVariantType arg;
	};

	/**
	* @brief Implements an operator to return a value specified in the JSON that is
	* chosen based on if the value passed into the operator is less than the lowest
	* arg_value it is true for or the given `default_value` if not found to be less
	* than any entries.
	*
	* "modifier": {
	* "operator": "less_than",
	* "default_value": 1000, // OPTIONAL
	* "value": [
	* {
	* "arg_value": 30, // if value is less than 30
	* "parameter_value": 300 // then return 300
	* },
	* {
	* "arg_value": 40, // else if value is less than 40
	* "parameter_value": 400 // then return 400
	* },
	* ]
	* }
	*
	* If the value passed in is higher than the highest arg_value, it returns a
	* default value this is the `default_value` given or based on the data type of
	* parameter_value.
	*/
	struct LessThanOperator : public Modifier::BaseOperator
	{
	explicit LessThanOperator(const json& jsonObj)
	{
	const auto& valueArray = jsonObj["value"];
	if (!valueArray.is_array())
	{
	log<level::ERR>(
	std::format("Invalid JSON data for less_than config: {}",
	valueArray.dump())
	.c_str());
	throw std::invalid_argument("Invalid modifier JSON");
	}

	for (const auto& valueEntry : valueArray)
	{
	if (!valueEntry.contains("arg_value") \|\|
	!valueEntry.contains("parameter_value"))
	{
	log<level::ERR>(
	std::format("Missing arg_value or parameter_value keys "
	"in less_than config: {}",
	valueArray.dump())
	.c_str());
	throw std::invalid_argument("Invalid modifier JSON");
	}

	auto argVal = ConfigBase::getJsonValue(valueEntry.at("arg_value"));

	if (std::holds_alternative<bool>(argVal))
	{
	log<level::ERR>(
	std::format(
	"Invalid data type in arg_value key in modifier JSON "
	"config: {}",
	valueArray.dump())
	.c_str());
	throw std::invalid_argument("Invalid modifier JSON");
	}

	auto paramVal =
	ConfigBase::getJsonValue(valueEntry.at("parameter_value"));

	rangeValues.emplace_back(argVal, paramVal);
	}

	if (rangeValues.empty())
	{
	log<level::ERR>(std::format("No valid range values found in "
	"modifier json: {}",
	valueArray.dump())
	.c_str());
	throw std::invalid_argument("Invalid modifier JSON");
	}

	if (jsonObj.contains("default_value"))
	{
	defaultValue = ConfigBase::getJsonValue(jsonObj["default_value"]);
	}
	}

	PropertyVariantType operator()(double val) override
	{
	for (const auto& rangeValue : rangeValues)
	{
	if (val < std::visit(ToTypeVisitor<double>(), rangeValue.first))
	{
	return rangeValue.second;
	}
	}
	// Return a default value based on last entry type
	return getDefaultValue(rangeValues.back().second, defaultValue);
	}

	PropertyVariantType operator()(int32_t val) override
	{
	for (const auto& rangeValue : rangeValues)
	{
	if (val < std::visit(ToTypeVisitor<int32_t>(), rangeValue.first))
	{
	return rangeValue.second;
	}
	}
	return getDefaultValue(rangeValues.back().second, defaultValue);
	}

	PropertyVariantType operator()(int64_t val) override
	{
	for (const auto& rangeValue : rangeValues)
	{
	if (val < std::visit(ToTypeVisitor<int64_t>(), rangeValue.first))
	{
	return rangeValue.second;
	}
	}
	return getDefaultValue(rangeValues.back().second, defaultValue);
	}

	PropertyVariantType operator()(const std::string& val) override
	{
	for (const auto& rangeValue : rangeValues)
	{
	if (val <
	std::visit(ToTypeVisitor<std::string>(), rangeValue.first))
	{
	return rangeValue.second;
	}
	}
	return getDefaultValue(rangeValues.back().second, defaultValue);
	}

	PropertyVariantType operator()(bool) override
	{
	throw std::runtime_error{
	"Bool not allowed as a 'less_than' modifier value"};
	}

	std::vector<std::pair<PropertyVariantType, PropertyVariantType>>
	rangeValues;
	std::optional<PropertyVariantType> defaultValue;
	};

	Modifier::Modifier(const json& jsonObj)
	{
	setOperator(jsonObj);
	}

	void Modifier::setOperator(const json& jsonObj)
	{
	if (!jsonObj.contains("operator") \|\| !jsonObj.contains("value"))
	{
	log<level::ERR>(
	std::format(
	"Modifier entry in JSON missing 'operator' or 'value': {}",
	jsonObj.dump())
	.c_str());
	throw std::invalid_argument("Invalid modifier JSON");
	}

	auto op = jsonObj["operator"].get<std::string>();

	if (op == "minus")
	{
	_operator = std::make_unique<MinusOperator>(jsonObj);
	}
	else if (op == "less_than")
	{
	_operator = std::make_unique<LessThanOperator>(jsonObj);
	}
	else
	{
	log<level::ERR>(std::format("Invalid operator in the modifier JSON: {}",
	jsonObj.dump())
	.c_str());
	throw std::invalid_argument("Invalid operator in the modifier JSON");
	}
	}

	PropertyVariantType Modifier::doOp(const PropertyVariantType& val)
	{
	return std::visit(*_operator, val);
	}

	} // namespace phosphor::fan::control::json