commit 8290e0f3297a2c5cbaa8d872d5cf8e19166ca177
author Jonathan Doman <jonathan.doman@intel.com> Wed Nov 23 15:04:17 2022 -0800
committer Jonathan Doman <jonathan.doman@intel.com> Tue Dec 13 10:48:57 2022 -0800
tree 726ac4f5392fb8fab8a55443e0e53a92eba5375e
parent c7fed5ca79cfb6b08d5023633072ee8885c4d62f

Use binary serialization instead of JSON

The binary format is much more efficient than JSON in terms of
computational speed and disk space consumption. The former is important
in case the host is sending a constant stream of POST codes.
post-code-manager can fall behind because it takes too long to store
each new POST code on disk, causing D-Bus messages to pile up and
increase memory consumption inside dbus-broker.

Tested:
Rebooted the host a few times and observed that POST code history is
populated normally in Redfish. After upgrading to this change, old POST
code history stored in JSON format is lost, but remains on disk until it
gets overwritten during subsequent host boots.

Signed-off-by: Jonathan Doman <jonathan.doman@intel.com>
Change-Id: Id55909a55d950e6e62b78b3333df687b4c582c42

inc/post_code.hpp

diff --git a/inc/post_code.hpp b/inc/post_code.hpp
index 243feaf..3ae58d8 100644
--- a/inc/post_code.hpp
+++ b/inc/post_code.hpp
@@ -18,12 +18,6 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#include <cereal/access.hpp>
-#include <cereal/archives/json.hpp>
-#include <cereal/cereal.hpp>
-#include <cereal/types/map.hpp>
-#include <cereal/types/tuple.hpp>
-#include <cereal/types/vector.hpp>
 #include <phosphor-logging/elog-errors.hpp>
 #include <xyz/openbmc_project/Collection/DeleteAll/server.hpp>
 #include <xyz/openbmc_project/Common/error.hpp>

src/post_code.cpp

diff --git a/src/post_code.cpp b/src/post_code.cpp
index 6186f97..8ab2e32 100644
--- a/src/post_code.cpp
+++ b/src/post_code.cpp
@@ -15,6 +15,13 @@
 */
 #include "post_code.hpp"
 
+#include <cereal/access.hpp>
+#include <cereal/archives/binary.hpp>
+#include <cereal/cereal.hpp>
+#include <cereal/types/map.hpp>
+#include <cereal/types/tuple.hpp>
+#include <cereal/types/vector.hpp>
+
 #include <iomanip>
 
 void PostCode::deleteAll()
@@ -124,16 +131,16 @@
     try
     {
         std::ofstream osIdx(path / CurrentBootCycleIndexName, std::ios::binary);
-        cereal::JSONOutputArchive idxArchive(osIdx);
+        cereal::BinaryOutputArchive idxArchive(osIdx);
         idxArchive(currentBootCycleIndex);
 
         uint16_t count = currentBootCycleCount();
         std::ofstream osCnt(path / CurrentBootCycleCountName, std::ios::binary);
-        cereal::JSONOutputArchive cntArchive(osCnt);
+        cereal::BinaryOutputArchive cntArchive(osCnt);
         cntArchive(count);
 
         std::ofstream osPostCodes(path / std::to_string(currentBootCycleIndex));
-        cereal::JSONOutputArchive oarchivePostCodes(osPostCodes);
+        cereal::BinaryOutputArchive oarchivePostCodes(osPostCodes);
         oarchivePostCodes(postCodes);
     }
     catch (const cereal::Exception& e)
@@ -156,7 +163,7 @@
         if (fs::exists(path))
         {
             std::ifstream is(path, std::ios::in | std::ios::binary);
-            cereal::JSONInputArchive iarchive(is);
+            cereal::BinaryInputArchive iarchive(is);
             iarchive(index);
             return true;
         }
@@ -183,7 +190,7 @@
         if (fs::exists(path))
         {
             std::ifstream is(path, std::ios::in | std::ios::binary);
-            cereal::JSONInputArchive iarchive(is);
+            cereal::BinaryInputArchive iarchive(is);
             iarchive(codes);
             return true;
         }