commit 0a83873508c542b21f99e2b5e1a2605f91916f4f
author Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com> Thu Oct 05 12:43:19 2017 +0530
committer Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com> Fri Oct 06 13:29:52 2017 +0530
tree 5b5469d61fab993255cd05ac26dd30c2ff8d4783
parent 4e6534f5b2520228a275941e2f3f5a495f41b9aa

Enable Cereal class versioning

Cereal class versioning helps to handle data de-serialization
across different class versions that differ in the way, a particular
data is serialized.

For more reading, refer Cereal official documentation;
http://uscilab.github.io/cereal/serialization_functions.html

Change-Id: Ic5d01090b7a7679ef2bf638da786abbd033007bc
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>

configure.ac

diff --git a/configure.ac b/configure.ac
index 28f51ae..49bc3dc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -69,5 +69,9 @@
 AC_CHECK_HEADER(sdbusplus/server.hpp, ,[AC_MSG_ERROR([Could not find sdbusplus/server.hpp...openbmc/sdbusplus package required])])
 AC_CHECK_HEADER(phosphor-logging/log.hpp, ,[AC_MSG_ERROR([Could not find phosphor-logging/log.hpp...openbmc/phosphor-logging package required])])
 
+AC_ARG_VAR(CLASS_VERSION, [Class version to register with Cereal])
+AS_IF([test "x$CLASS_VERSION" == "x"], [CLASS_VERSION=1])
+AC_DEFINE_UNQUOTED([CLASS_VERSION], [$CLASS_VERSION], [Class version to register with Cereal])
+
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT

host_state_manager.cpp

diff --git a/host_state_manager.cpp b/host_state_manager.cpp
index 8debe8a..884372d 100644
--- a/host_state_manager.cpp
+++ b/host_state_manager.cpp
@@ -16,6 +16,8 @@
 #include "host_state_manager.hpp"
 #include "config.h"
 
+// Register class version with Cereal
+CEREAL_CLASS_VERSION(phosphor::state::manager::Host, CLASS_VERSION);
 
 namespace phosphor
 {

host_state_manager.hpp

diff --git a/host_state_manager.hpp b/host_state_manager.hpp
index 35a4bdd..6b5e97e 100644
--- a/host_state_manager.hpp
+++ b/host_state_manager.hpp
@@ -4,6 +4,7 @@
 #include <functional>
 #include <experimental/filesystem>
 #include <cereal/access.hpp>
+#include <cereal/cereal.hpp>
 #include <sdbusplus/bus.hpp>
 #include <phosphor-logging/log.hpp>
 #include <xyz/openbmc_project/State/Boot/Progress/server.hpp>
@@ -184,9 +185,11 @@
          *
          *  @tparam Archive - Cereal archive type (binary in our case).
          *  @param[in] archive - reference to Cereal archive.
+         *  @param[in] version - Class version that enables handling
+         *                       a serialized data across code levels
          */
         template<class Archive>
-        void save(Archive& archive) const
+        void save(Archive& archive, const std::uint32_t version) const
         {
             archive(convertForMessage(sdbusplus::xyz::openbmc_project::
                                       State::server::Host::
@@ -203,9 +206,11 @@
          *
          *  @tparam Archive - Cereal archive type (binary in our case).
          *  @param[in] archive - reference to Cereal archive.
+         *  @param[in] version - Class version that enables handling
+         *                       a serialized data across code levels
          */
         template<class Archive>
-        void load(Archive& archive)
+        void load(Archive& archive, const std::uint32_t version)
         {
             std::string reqTranState;
             std::string bootProgress;