Add API to retrieve settings

Add API to retrieve all settings objects of interest to this repo, in
one shot.

Change-Id: Ie74d39f4d6b1d262e6e5721208efc94003eee46c
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
diff --git a/settings.hpp b/settings.hpp
new file mode 100644
index 0000000..088628a
--- /dev/null
+++ b/settings.hpp
@@ -0,0 +1,57 @@
+#pragma once
+
+#include <string>
+#include <sdbusplus/bus.hpp>
+
+namespace settings
+{
+
+using Path = std::string;
+using Service = std::string;
+using Interface = std::string;
+
+constexpr auto root = "/";
+constexpr auto autoRebootIntf =
+    "xyz.openbmc_project.Control.Boot.RebootPolicy";
+constexpr auto powerRestoreIntf =
+    "xyz.openbmc_project.Control.Power.RestorePolicy";
+
+/** @class Objects
+ *  @brief Fetch paths of settings d-bus objects of interest, upon construction
+ */
+struct Objects
+{
+    public:
+        /** @brief Constructor - fetch settings objects
+         *
+         * @param[in] bus - The Dbus bus object
+         */
+        Objects(sdbusplus::bus::bus& bus);
+        Objects(const Objects&) = delete;
+        Objects& operator=(const Objects&) = delete;
+        Objects(Objects&&) = delete;
+        Objects& operator=(Objects&&) = delete;
+        ~Objects() = default;
+
+        /** @brief Fetch d-bus service, given a path and an interface. The
+         *         service can't be cached because mapper returns unique
+         *         service names.
+         *
+         * @param[in] path - The Dbus object
+         * @param[in] interface - The Dbus interface
+         *
+         * @return std::string - the dbus service name
+         */
+        Service service(const Path& path, const Interface& interface) const;
+
+        /** @brief host auto_reboot settings object */
+        Path autoReboot;
+
+        /** @brief host power_restore_policy settings object */
+        Path powerRestorePolicy;
+
+        /** @brief The Dbus bus object */
+        sdbusplus::bus::bus& bus;
+};
+
+} // namespace settings