Create regulators ActionEnvironment class
Create the ActionEnvironment class used in the regulators action
framework.
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I9d5493cd9d3b8594076e5a97628b61a152c8c500
diff --git a/phosphor-regulators/src/actions/action_environment.hpp b/phosphor-regulators/src/actions/action_environment.hpp
new file mode 100644
index 0000000..fb34141
--- /dev/null
+++ b/phosphor-regulators/src/actions/action_environment.hpp
@@ -0,0 +1,230 @@
+/**
+ * Copyright © 2019 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.
+ */
+#pragma once
+
+#include "device.hpp"
+#include "id_map.hpp"
+#include "rule.hpp"
+
+#include <cstddef> // for size_t
+#include <stdexcept>
+#include <string>
+
+namespace phosphor
+{
+namespace power
+{
+namespace regulators
+{
+
+/**
+ * @class ActionEnvironment
+ *
+ * The current environment when executing actions.
+ *
+ * The ActionEnvironment contains the following information:
+ * - current device ID
+ * - current volts value (if any)
+ * - mapping from device and rule IDs to the corresponding objects
+ * - rule call stack depth (to detect infinite recursion)
+ */
+class ActionEnvironment
+{
+ public:
+ // Specify which compiler-generated methods we want
+ ActionEnvironment() = delete;
+ ActionEnvironment(const ActionEnvironment&) = delete;
+ ActionEnvironment(ActionEnvironment&&) = delete;
+ ActionEnvironment& operator=(const ActionEnvironment&) = delete;
+ ActionEnvironment& operator=(ActionEnvironment&&) = delete;
+ ~ActionEnvironment() = default;
+
+ /**
+ * Maximum rule call stack depth. Used to detect infinite recursion.
+ */
+ static constexpr size_t maxRuleDepth{30};
+
+ /**
+ * Constructor.
+ *
+ * @param idMap mapping from IDs to the associated Device/Rule objects
+ * @param deviceID current device ID
+ */
+ explicit ActionEnvironment(const IDMap& idMap,
+ const std::string& deviceID) :
+ idMap{idMap},
+ deviceID{deviceID}
+ {
+ }
+
+ /**
+ * Decrements the rule call stack depth by one.
+ *
+ * Should be used when a call to a rule returns. Does nothing if depth is
+ * already 0.
+ */
+ void decrementRuleDepth()
+ {
+ if (ruleDepth > 0)
+ {
+ --ruleDepth;
+ }
+ }
+
+ /**
+ * Returns the device with the current device ID.
+ *
+ * Throws invalid_argument if no device is found with current ID.
+ *
+ * @return device with current device ID
+ */
+ Device& getDevice() const
+ {
+ return idMap.getDevice(deviceID);
+ }
+
+ /**
+ * Returns the current device ID.
+ *
+ * @return current device ID
+ */
+ const std::string& getDeviceID() const
+ {
+ return deviceID;
+ }
+
+ /**
+ * Returns the rule with the specified ID.
+ *
+ * Throws invalid_argument if no rule is found with specified ID.
+ *
+ * @param id rule ID
+ * @return rule with specified ID
+ */
+ Rule& getRule(const std::string& id) const
+ {
+ return idMap.getRule(id);
+ }
+
+ /**
+ * Returns the current rule call stack depth.
+ *
+ * The depth is 0 if no rules have been called.
+ *
+ * @return rule call stack depth
+ */
+ size_t getRuleDepth() const
+ {
+ return ruleDepth;
+ }
+
+ /**
+ * Returns the current volts value.
+ *
+ * Call hasVolts() first to check whether a volts value has been set.
+ *
+ * Throws logic_error if no volts value has been set.
+ *
+ * @return current volts value
+ */
+ double getVolts() const
+ {
+ if (!hasVoltsValue)
+ {
+ throw std::logic_error{"No volts value has been set."};
+ }
+ return volts;
+ }
+
+ /**
+ * Returns whether a volts value has been set.
+ *
+ * @return true if a volts value has been set, false otherwise
+ */
+ bool hasVolts() const
+ {
+ return hasVoltsValue;
+ }
+
+ /**
+ * Increments the rule call stack depth by one.
+ *
+ * Should be used when a rule is called.
+ *
+ * Throws runtime_error if the new depth exceeds maxRuleDepth. This
+ * indicates that infinite recursion has probably occurred (rule A -> rule B
+ * -> rule A).
+ */
+ void incrementRuleDepth()
+ {
+ if (ruleDepth >= maxRuleDepth)
+ {
+ throw std::runtime_error("Maximum rule depth exceeded.");
+ }
+ ++ruleDepth;
+ }
+
+ /**
+ * Sets the current device ID.
+ *
+ * @param id device ID
+ */
+ void setDeviceID(const std::string& id)
+ {
+ deviceID = id;
+ }
+
+ /**
+ * Sets the current volts value.
+ *
+ * @param volts new volts value.
+ */
+ void setVolts(double volts)
+ {
+ this->volts = volts;
+ hasVoltsValue = true;
+ }
+
+ private:
+ /**
+ * Mapping from string IDs to the associated Device and Rule objects.
+ */
+ const IDMap& idMap{};
+
+ /**
+ * Current device ID.
+ */
+ std::string deviceID{};
+
+ /**
+ * Indicates whether a volts value has been set.
+ */
+ bool hasVoltsValue{false};
+
+ /**
+ * Current volts value (if set).
+ */
+ double volts{0};
+
+ /**
+ * Rule call stack depth.
+ */
+ size_t ruleDepth{0};
+};
+
+} // namespace regulators
+} // namespace power
+} // namespace phosphor