Add API to retrieve settings

Add API to retrieve and cache settings objects of interest.

Change-Id: I8afd58b5b3e9a691e4d3fa6bfba2ba5c92cd2568
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/settings.cpp b/settings.cpp
new file mode 100644
index 0000000..cb86d99
--- /dev/null
+++ b/settings.cpp
@@ -0,0 +1,82 @@
+#include <phosphor-logging/elog-errors.hpp>
+#include <phosphor-logging/log.hpp>
+#include "xyz/openbmc_project/Common/error.hpp"
+#include "settings.hpp"
+
+namespace settings
+{
+
+using namespace phosphor::logging;
+using namespace sdbusplus::xyz::openbmc_project::Common::Error;
+
+constexpr auto mapperService = "xyz.openbmc_project.ObjectMapper";
+constexpr auto mapperPath = "/xyz/openbmc_project/object_mapper";
+constexpr auto mapperIntf = "xyz.openbmc_project.ObjectMapper";
+
+Objects::Objects(sdbusplus::bus::bus& bus,
+                 const std::vector<Interface>& filter):
+    bus(bus)
+{
+    auto depth = 0;
+
+    auto mapperCall = bus.new_method_call(mapperService,
+                                          mapperPath,
+                                          mapperIntf,
+                                          "GetSubTree");
+    mapperCall.append(root);
+    mapperCall.append(depth);
+    mapperCall.append(filter);
+    auto response = bus.call(mapperCall);
+    if (response.is_method_error())
+    {
+        log<level::ERR>("Error in mapper GetSubTree");
+        elog<InternalFailure>();
+    }
+
+    using Interfaces = std::vector<Interface>;
+    using MapperResponse = std::map<Path, std::map<Service, Interfaces>>;
+    MapperResponse result;
+    response.read(result);
+    if (result.empty())
+    {
+        log<level::ERR>("Invalid response from mapper");
+        elog<InternalFailure>();
+    }
+
+    for (auto& iter : result)
+    {
+        const auto& path = iter.first;
+        auto& interface = iter.second.begin()->second[0];
+        map.emplace(std::move(interface), path);
+    }
+}
+
+Service Objects::service(const Path& path, const Interface& interface) const
+{
+    using Interfaces = std::vector<Interface>;
+    auto mapperCall = bus.new_method_call(mapperService,
+                                          mapperPath,
+                                          mapperIntf,
+                                          "GetObject");
+    mapperCall.append(path);
+    mapperCall.append(Interfaces({interface}));
+
+    auto response = bus.call(mapperCall);
+    if (response.is_method_error())
+    {
+        log<level::ERR>("Error in mapper GetObject");
+        elog<InternalFailure>();
+    }
+
+    std::map<Service, Interfaces> result;
+    response.read(result);
+    if (result.empty())
+    {
+        log<level::ERR>("Invalid response from mapper");
+        elog<InternalFailure>();
+    }
+
+    return result.begin()->first;
+}
+
+} // namespace settings