commit f3e7047071b3afebbe1813971d6b8de7cd127da6
author Matthew Barth <msbarth@us.ibm.com> Tue Dec 03 13:33:20 2019 -0600
committer Matthew Barth <msbarth@us.ibm.com> Thu Jan 09 11:00:24 2020 -0600
tree f4d09ef4a07f33e458cf1be96665c4b662bbffd7
parent 26ad44a8b11d66b6833a196411043dd4d655bfc6

presence: Reload json config on SIGHUP

Enable capturing the HUP signal to reload the json configuration. This
will reload and process the default json config file, updating the set
of policies to be the same set of policies from when fan presence was
started.

Tested:
    Configuration is reloaded and processed after SIGHUP
    Single set of policies exist that correlate to the json config

Change-Id: I761ac3779baf5b058308d7c565fd117fe052d61c
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>

presence/json_config.hpp

diff --git a/presence/json_config.hpp b/presence/json_config.hpp
index b027dba..a369bd5 100644
--- a/presence/json_config.hpp
+++ b/presence/json_config.hpp
@@ -4,6 +4,8 @@
 #include <vector>
 #include <memory>
 #include <nlohmann/json.hpp>
+#include <filesystem>
+#include <sdeventplus/source/signal.hpp>
 
 #include "config.h"
 #include "rpolicy.hpp"
@@ -17,6 +19,7 @@
 namespace presence
 {
 
+namespace fs = std::filesystem;
 using json = nlohmann::json;
 using policies = std::vector<std::unique_ptr<RedundancyPolicy>>;
 
@@ -57,11 +60,24 @@
          */
         static const policies& get();
 
+        /**
+         * @brief Callback function to handle receiving a HUP signal to
+         * reload the json configuration.
+         *
+         * @param[in] sigSrc - sd_event_source signal wrapper
+         * @param[in] sigInfo - signal info on signal fd
+         */
+        void sighupHandler(sdeventplus::source::Signal& sigSrc,
+                           const struct signalfd_siginfo* sigInfo);
+
     private:
 
         /* Fan presence policies */
         static policies _policies;
 
+        /* Default json configuration file */
+        const fs::path _defaultFile;
+
         /* List of Fan objects to have presence policies */
         std::vector<fanPolicy> _fans;
 
@@ -75,6 +91,11 @@
         static const std::map<std::string, rpolicyHandler> _rpolicies;
 
         /**
+         * @brief Load the json config file
+         */
+        void load();
+
+        /**
          * @brief Process the json config to extract the defined fan presence
          * policies.
          *
@@ -83,11 +104,15 @@
         void process(const json& jsonConf);
 
         /**
-         * @brief Add to the list of policies of presence detection
+         * @brief Get the redundancy policy of presence detection for a fan
          *
-         * @param[in] rpolicy - policy to add
+         * @param[in] rpolicy - policy type to construct
+         * @param[in] fpolicy - fan policy object
+         *
+         * @return - The constructed redundancy policy type for the fan
          */
-        void addPolicy(const json& rpolicy);
+        std::unique_ptr<RedundancyPolicy> getPolicy(const json& rpolicy,
+                                                    const fanPolicy& fpolicy);
 };
 
 /**