control/json/actions/net_target_decrease.cpp

/**
 * 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 "net_target_decrease.hpp"

#include "../manager.hpp"
#include "../zone.hpp"
#include "action.hpp"
#include "group.hpp"

#include <fmt/format.h>

#include <nlohmann/json.hpp>
#include <phosphor-logging/log.hpp>

#include <algorithm>
#include <variant>

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

using json = nlohmann::json;
using namespace phosphor::logging;

NetTargetDecrease::NetTargetDecrease(const json& jsonObj,
                                     const std::vector<Group>& groups) :
    ActionBase(jsonObj, groups)
{
    setState(jsonObj);
    setDelta(jsonObj);
}

void NetTargetDecrease::run(Zone& zone, const Group& group)
{
    auto netDelta = zone.getDecDelta();
    for (const auto& member : group.getMembers())
    {
        try
        {
            auto value = Manager::getObjValueVariant(
                member, group.getInterface(), group.getProperty());
            if (std::holds_alternative<int64_t>(value) ||
                std::holds_alternative<double>(value))
            {
                if (value >= _state)
                {
                    // No decrease allowed for this group
                    netDelta = 0;
                    break;
                }
                else
                {
                    // Decrease factor is the difference in configured state to
                    // the current value's state
                    uint64_t deltaFactor = 0;
                    if (auto dblPtr = std::get_if<double>(&value))
                    {
                        deltaFactor = static_cast<uint64_t>(
                            std::get<double>(_state) - *dblPtr);
                    }
                    else
                    {
                        deltaFactor =
                            static_cast<uint64_t>(std::get<int64_t>(_state) -
                                                  std::get<int64_t>(value));
                    }

                    // Multiply the decrease factor by the configured delta to
                    // get the net decrease delta for the given group member.
                    // The lowest net decrease delta of the entire group is the
                    // decrease requested.
                    if (netDelta == 0)
                    {
                        netDelta = deltaFactor * _delta;
                    }
                    else
                    {
                        netDelta = std::min(netDelta, deltaFactor * _delta);
                    }
                }
            }
            else if (std::holds_alternative<bool>(value) ||
                     std::holds_alternative<std::string>(value))
            {
                // Where a group of booleans or strings equal the state
                // provided, request a decrease of the configured delta
                if (_state == value)
                {
                    if (netDelta == 0)
                    {
                        netDelta = _delta;
                    }
                    else
                    {
                        netDelta = std::min(netDelta, _delta);
                    }
                }
            }
            else
            {
                // Unsupported group member type for this action
                log<level::ERR>(
                    fmt::format("Action {}: Unsupported group member type "
                                "given. [object = {} : {} : {}]",
                                ActionBase::getName(), member,
                                group.getInterface(), group.getProperty())
                        .c_str());
            }
        }
        catch (const std::out_of_range& oore)
        {
            // Property value not found, netDelta unchanged
        }
    }
    // Update group's decrease allowed state
    zone.setDecreaseAllow(group.getName(), !(netDelta == 0));
    // Request target decrease to occur on decrease interval
    zone.requestDecrease(netDelta);
}

void NetTargetDecrease::setState(const json& jsonObj)
{
    if (!jsonObj.contains("state"))
    {
        throw ActionParseError{ActionBase::getName(),
                               "Missing required state value"};
    }
    _state = getJsonValue(jsonObj["state"]);
}

void NetTargetDecrease::setDelta(const json& jsonObj)
{
    if (!jsonObj.contains("delta"))
    {
        throw ActionParseError{ActionBase::getName(),
                               "Missing required delta value"};
    }
    _delta = jsonObj["delta"].get<uint64_t>();
}

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