Add support for changing the content of the finalizer safety info (fsi) file and loading older versions

libraries/chain/finality/finalizer.cpp

@@ -186,6 +186,7 @@ void my_finalizers_t::save_finalizer_safety_info() const {
 
       persist_file.seek(0);
       fc::raw::pack(persist_file, fsi_t::magic);
+      fc::raw::pack(persist_file, current_safety_file_version);
       fc::raw::pack(persist_file, (uint64_t)(finalizers.size() + inactive_safety_info.size()));
       for (const auto& [pub_key, f] : finalizers) {
          fc::raw::pack(persist_file, pub_key);
@@ -235,10 +236,26 @@ my_finalizers_t::fsi_map my_finalizers_t::load_finalizer_safety_info() {
    }
    try {
       persist_file.seek(0);
+
+      // read magic number. Can be `fsi_t::magic_unversioned` (for files without embedded version number)
+      // or `fsi_t::magic` (for files with a version number right after `magic`).
+      // ------------------------------------------------------------------------------------------------
       uint64_t magic = 0;
       fc::raw::unpack(persist_file, magic);
-      EOS_ASSERT(magic == fsi_t::magic, finalizer_safety_exception,
+      EOS_ASSERT(magic == fsi_t::magic_unversioned || magic == fsi_t::magic, finalizer_safety_exception,
                  "bad magic number in finalizer safety persistence file: ${p}", ("p", persist_file_path));
+
+      // If we expect the file to contain a version number, read it. We can load files with older
+      // versions, but it better not be a file with a version higher that the running nodeos understands.
+      // ------------------------------------------------------------------------------------------------
+      uint64_t file_version = 0; // default version for file with magic == fsi_t::magic_unversioned
+      if (magic != fsi_t::magic_unversioned)
+         fc::raw::unpack(persist_file, file_version);
+      EOS_ASSERT(file_version <= current_safety_file_version, finalizer_safety_exception,
+                 "Incorrect version number in finalizer safety persistence file: ${p}", ("p", persist_file_path));
+
+      // finally read the `finalizer_safety_information` info
+      // ----------------------------------------------------
       uint64_t num_finalizers {0};
       fc::raw::unpack(persist_file, num_finalizers);
       for (size_t i=0; i<num_finalizers; ++i) {
@@ -248,6 +265,7 @@ my_finalizers_t::fsi_map my_finalizers_t::load_finalizer_safety_info() {
          fc::raw::unpack(persist_file, fsi);
          res.emplace(pubkey, fsi);
       }
+
       persist_file.close();
    } FC_LOG_AND_RETHROW()
    // don't remove file we can't load
@@ -305,4 +323,16 @@ void my_finalizers_t::set_default_safety_information(const fsi_t& fsi) {
    default_fsi = fsi;
 }
 
+bool  my_finalizers_t::are_equivalent(uint32_t version, const fsi_map& old, const fsi_map& current) {
+   assert(version < current_safety_file_version); // this function compares an older version with the current one
+   switch(version) {
+   case 0:
+      return old == current;
+      break;
+   default:
+      assert(0);
+      return false;
+   }
+}
+
 } // namespace eosio::chain

libraries/chain/include/eosio/chain/finality/finalizer.hpp

@@ -36,7 +36,8 @@ namespace eosio::chain {
       block_ref            last_vote;
       block_ref            lock;
 
-      static constexpr uint64_t magic = 0x5AFE11115AFE1111ull;
+      static constexpr uint64_t magic_unversioned = 0x5AFE11115AFE1111ull;
+      static constexpr uint64_t magic             = 0x5AFE11115AFE1112ull;
 
       static finalizer_safety_information unset_fsi() { return {}; }
 
@@ -69,6 +70,9 @@ namespace eosio::chain {
 
    // ----------------------------------------------------------------------------------------
    struct my_finalizers_t {
+   public:
+      static constexpr uint64_t current_safety_file_version = 1;
+
       using fsi_t   = finalizer_safety_information;
       using fsi_map = std::map<bls_public_key, fsi_t>;
 
@@ -155,6 +159,7 @@ namespace eosio::chain {
       // for testing purposes only, not thread safe
       const fsi_t& get_fsi(const bls_public_key& k) { return finalizers[k].fsi; }
       void         set_fsi(const bls_public_key& k, const fsi_t& fsi) { finalizers[k].fsi = fsi; }
+      static bool  are_equivalent(uint32_t version, const fsi_map& old, const fsi_map& current);
    };
 
 }

unittests/CMakeLists.txt

@@ -61,6 +61,8 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/snapshots.hpp.in ${CMAKE_CURRENT_BINA
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/deep-mind/deep-mind.hpp.in ${CMAKE_CURRENT_BINARY_DIR}/include/deep-mind.hpp ESCAPE_QUOTES)
 
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/test-data/test-data.hpp.in ${CMAKE_CURRENT_BINARY_DIR}/include/test-data.hpp ESCAPE_QUOTES)
+
 add_custom_command(
    OUTPUT protocol_feature_digest_tests.cpp
    COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/gen_protocol_feature_digest_tests.py ${CMAKE_CURRENT_SOURCE_DIR}/../libraries/chain/protocol_feature_manager.cpp > protocol_feature_digest_tests.cpp

unittests/finalizer_tests.cpp

@@ -4,13 +4,16 @@
 #include <eosio/testing/tester.hpp>
 #include <eosio/testing/bls_utils.hpp>
 #include <fc/io/cfile.hpp>
+#include <test-data.hpp>
 
 using namespace eosio;
 using namespace eosio::chain;
 using namespace eosio::testing;
+using namespace std::string_literals;
 
 using tstamp  = block_timestamp_type;
 using fsi_t   = finalizer_safety_information;
+using fsi_map = my_finalizers_t::fsi_map;
 
 struct bls_keys_t {
    bls_private_key privkey;
@@ -29,10 +32,16 @@ template<class FSI>
 std::vector<FSI> create_random_fsi(size_t count) {
    std::vector<FSI> res;
    res.reserve(count);
-   for (size_t i=0; i<count; ++i) {
-      res.push_back(FSI{tstamp(i),
-                        block_ref{sha256::hash((const char *)"vote"), tstamp(i*100 + 3)},
-                        block_ref{sha256::hash((const char *)"lock"), tstamp(i*100)} });
+   for (size_t i = 0; i < count; ++i) {
+      res.push_back(FSI{
+         .last_vote_range_start = tstamp(i),
+         .last_vote             = block_ref{.block_id        = sha256::hash("vote"s + std::to_string(i)),
+                                            .timestamp       = tstamp(i * 100 + 3),
+                                            .finality_digest = sha256::hash("vote_digest"s + std::to_string(i))},
+         .lock                  = block_ref{.block_id        = sha256::hash("lock"s + std::to_string(i)),
+                                            .timestamp       = tstamp(i * 100),
+                                            .finality_digest = sha256::hash("lock_digest"s + std::to_string(i))}
+      });
       if (i)
          assert(res.back() != res[0]);
    }
@@ -210,4 +219,52 @@ BOOST_AUTO_TEST_CASE( finalizer_safety_file_io ) try {
 } FC_LOG_AND_RETHROW()
 
 
+BOOST_AUTO_TEST_CASE( finalizer_safety_file_versioning ) try {
+   std::filesystem::path test_data_path { UNITTEST_TEST_DATA_DIR };
+   auto fsi_reference_dir = test_data_path / "fsi";
+
+   auto create_fsi_reference = [&](my_finalizers_t& fset) {
+      std::vector<bls_keys_t> keys = create_keys(3);
+      std::vector<fsi_t> fsi = create_random_fsi<fsi_t>(3);
+
+      bls_pub_priv_key_map_t local_finalizers = create_local_finalizers<0, 1, 2>(keys);
+      fset.set_keys(local_finalizers);
+      set_fsi<decltype(fsi), 0, 1, 2>(fset, keys, fsi);
+   };
+
+   auto create_fsi_reference_file = [&](const std::filesystem::path& safety_file_path) {
+      my_finalizers_t fset{safety_file_path};
+      create_fsi_reference(fset);
+      fset.save_finalizer_safety_info();
+   };
+
+   auto mk_versioned_fsi_file_path = [&](uint32_t v) {
+      return fsi_reference_dir / ("safety_v"s + std::to_string(v) + ".dat");
+   };
+
+   auto current_version = my_finalizers_t::current_safety_file_version;
+
+   // enable code below to create a new reference version of the finalizer_safety_file
+   if (0)
+      create_fsi_reference_file(mk_versioned_fsi_file_path(current_version));
+
+   auto load_fsi_map = [&](const std::filesystem::path& safety_file_path) {
+      BOOST_REQUIRE(std::filesystem::exists(safety_file_path));
+       my_finalizers_t fset{safety_file_path};
+       auto map = fset.load_finalizer_safety_info();
+       return map;
+   };
+
+   // make sure we can read previous versions of the safety file correctly
+   // --------------------------------------------------------------------
+   auto fsi_map_current = load_fsi_map(mk_versioned_fsi_file_path(current_version));
+
+   for (size_t i=0; i<current_version; ++i) {
+      auto fsi_map_vi = load_fsi_map(mk_versioned_fsi_file_path(i));
+      BOOST_REQUIRE(my_finalizers_t::are_equivalent(i, fsi_map_vi, fsi_map_current));
+   }
+
+} FC_LOG_AND_RETHROW()
+
+
 BOOST_AUTO_TEST_SUITE_END()

unittests/test-data/test-data.hpp.in

@@ -0,0 +1 @@
+#define UNITTEST_TEST_DATA_DIR "${CMAKE_CURRENT_SOURCE_DIR}/test-data"