Implement last_irreversible_block_num

libraries/chain/db_block.cpp

@@ -479,6 +479,7 @@ void database::_apply_block( const signed_block& next_block )
 
    update_global_dynamic_data(next_block);
    update_signing_witness(signing_witness, next_block);
+   update_last_irreversible_block();
 
    // Are we at the maintenance interval?
    if( maint_needed )

libraries/chain/db_update.cpp

@@ -108,9 +108,45 @@ void database::update_signing_witness(const witness_object& signing_witness, con
    modify( signing_witness, [&]( witness_object& _wit )
    {
       _wit.last_aslot = new_block_aslot;
+      _wit.last_confirmed_block_num = new_block.block_num();
    } );
 }
 
+void database::update_last_irreversible_block()
+{
+   const global_property_object& gpo = get_global_properties();
+   const dynamic_global_property_object& dpo = get_dynamic_global_properties();
+
+   vector< const witness_object* > wit_objs;
+   wit_objs.reserve( gpo.active_witnesses.size() );
+   for( const witness_id_type& wid : gpo.active_witnesses )
+      wit_objs.push_back( &(wid(*this)) );
+
+   static_assert( GRAPHENE_IRREVERSIBLE_THRESHOLD > 0, "irreversible threshold must be nonzero" );
+
+   // 1 1 1 2 2 2 2 2 2 2 -> 2     .7*10 = 7
+   // 1 1 1 1 1 1 1 2 2 2 -> 1
+   // 3 3 3 3 3 3 3 3 3 3 -> 3
+
+   size_t offset = ((GRAPHENE_100_PERCENT - GRAPHENE_IRREVERSIBLE_THRESHOLD) * wit_objs.size() / GRAPHENE_100_PERCENT);
+
+   std::nth_element( wit_objs.begin(), wit_objs.begin() + offset, wit_objs.end(),
+      []( const witness_object* a, const witness_object* b )
+      {
+         return a->last_confirmed_block_num < b->last_confirmed_block_num;
+      } );
+
+   uint32_t new_last_irreversible_block_num = wit_objs[offset]->last_confirmed_block_num;
+
+   if( new_last_irreversible_block_num > dpo.last_irreversible_block_num )
+   {
+      modify( dpo, [&]( dynamic_global_property_object& _dpo )
+      {
+         _dpo.last_irreversible_block_num = new_last_irreversible_block_num;
+      } );
+   }
+}
+
 void database::clear_expired_transactions()
 {
    //Look for expired transactions in the deduplication list, and remove them.

libraries/chain/include/graphene/chain/config.hpp

@@ -135,7 +135,9 @@
 #define GRAPHENE_RECENTLY_MISSED_COUNT_INCREMENT             4
 #define GRAPHENE_RECENTLY_MISSED_COUNT_DECREMENT             3
 
-#define GRAPHENE_CURRENT_DB_VERSION                          "test3d"
+#define GRAPHENE_CURRENT_DB_VERSION                          "test5b"
+
+#define GRAPHENE_IRREVERSIBLE_THRESHOLD                      (70 * GRAPHENE_1_PERCENT)
 
 /**
  *  Reserved Account IDs with special meaning

libraries/chain/include/graphene/chain/database.hpp

@@ -422,6 +422,7 @@ namespace graphene { namespace chain {
          //////////////////// db_update.cpp ////////////////////
          void update_global_dynamic_data( const signed_block& b );
          void update_signing_witness(const witness_object& signing_witness, const signed_block& new_block);
+         void update_last_irreversible_block();
          void clear_expired_transactions();
          void clear_expired_proposals();
          void clear_expired_orders();

libraries/chain/include/graphene/chain/global_property_object.hpp

@@ -101,6 +101,8 @@ namespace graphene { namespace chain {
           */
          uint32_t dynamic_flags = 0;
 
+         uint32_t last_irreversible_block_num = 0;
+
          enum dynamic_flag_bits
          {
             /**
@@ -129,6 +131,7 @@ FC_REFLECT_DERIVED( graphene::chain::dynamic_global_property_object, (graphene::
                     (current_aslot)
                     (recent_slots_filled)
                     (dynamic_flags)
+                    (last_irreversible_block_num)
                   )
 
 FC_REFLECT_DERIVED( graphene::chain::global_property_object, (graphene::db::object),

libraries/chain/include/graphene/chain/witness_object.hpp

@@ -38,7 +38,8 @@ namespace graphene { namespace chain {
          vote_id_type     vote_id;
          uint64_t         total_votes = 0;
          string           url;
-         int64_t          total_missed = 0;     
+         int64_t          total_missed = 0;
+         uint32_t         last_confirmed_block_num = 0;
 
          witness_object() : vote_id(vote_id_type::witness) {}
    };
@@ -72,4 +73,5 @@ FC_REFLECT_DERIVED( graphene::chain::witness_object, (graphene::db::object),
                     (total_votes)
                     (url) 
                     (total_missed)
+                    (last_confirmed_block_num)
                   )