delayed_node_plugin.cpp: Use new last_irreversible_block property, change to polling architecture

libraries/plugins/delayed_node/delayed_node_plugin.cpp

@@ -17,8 +17,8 @@
  */
 
 #include <graphene/delayed_node/delayed_node_plugin.hpp>
+#include <graphene/chain/protocol/types.hpp>
 #include <graphene/chain/database.hpp>
-#include <graphene/chain/worker_evaluator.hpp>
 #include <graphene/app/api.hpp>
 
 #include <fc/network/http/websocket.hpp>
@@ -33,12 +33,12 @@ namespace bpo = boost::program_options;
 namespace detail {
 struct delayed_node_plugin_impl {
    std::string remote_endpoint;
-   int delay_blocks;
    fc::http::websocket_client client;
    std::shared_ptr<fc::rpc::websocket_api_connection> client_connection;
    fc::api<graphene::app::database_api> database_api;
    boost::signals2::scoped_connection client_connection_closed;
-   bool currently_fetching = false;
+   graphene::chain::block_id_type last_received_remote_head;
+   graphene::chain::block_id_type last_processed_remote_head;
 };
 }
 
@@ -53,7 +53,6 @@ void delayed_node_plugin::plugin_set_program_options(bpo::options_description& c
 {
    cli.add_options()
          ("trusted-node", boost::program_options::value<std::string>()->required(), "RPC endpoint of a trusted validating node (required)")
-         ("delay-block-count", boost::program_options::value<int>()->required(), "Number of blocks to delay before advancing chain state (required)")
          ;
    cfg.add(cli);
 }
@@ -70,58 +69,79 @@ void delayed_node_plugin::connect()
 void delayed_node_plugin::plugin_initialize(const boost::program_options::variables_map& options)
 {
    my->remote_endpoint = "ws://" + options.at("trusted-node").as<std::string>();
-   my->delay_blocks = options.at("delay-block-count").as<int>();
 }
 
-void delayed_node_plugin::sync_with_trusted_node(uint32_t remote_head_block_num)
+void delayed_node_plugin::sync_with_trusted_node()
 {
-   struct raii {
+   auto& db = database();
-      bool* target;
+   uint32_t synced_blocks = 0;
-      ~raii() {
+   uint32_t pass_count = 0;
-         *target = false;
+   while( true )
+   {
+      graphene::chain::dynamic_global_property_object remote_dpo = my->database_api->get_dynamic_global_properties();
+      if( remote_dpo.last_irreversible_block_num <= db.head_block_num() )
+      {
+         if( remote_dpo.last_irreversible_block_num < db.head_block_num() )
+         {
+            wlog( "Trusted node seems to be behind delayed node" );
          }
-   };
+         if( synced_blocks > 1 )
-
+         {
-   if (my->currently_fetching) return;
+            ilog( "Delayed node finished syncing ${n} blocks in ${k} passes", ("n", synced_blocks)("k", pass_count) );
-   raii releaser{&my->currently_fetching};
+         }
-   my->currently_fetching = true;
+         break;
-
+      }
-   auto head_block = database().head_block_num();
+      pass_count++;
-   while (remote_head_block_num - head_block > my->delay_blocks) {
+      while( remote_dpo.last_irreversible_block_num > db.head_block_num() )
-      fc::optional<graphene::chain::signed_block> block = my->database_api->get_block(++head_block);
+      {
+         fc::optional<graphene::chain::signed_block> block = my->database_api->get_block( db.head_block_num()+1 );
          FC_ASSERT(block, "Trusted node claims it has blocks it doesn't actually have.");
          ilog("Pushing block #${n}", ("n", block->block_num()));
-      database().push_block(*block);
+         db.push_block(*block);
+         synced_blocks++;
+      }
+   }
+}
+
+void delayed_node_plugin::mainloop()
+{
+   while( true )
+   {
+      try
+      {
+         fc::usleep( fc::microseconds( 296645 ) );  // wake up a little over 3Hz
+
+         if( my->last_received_remote_head == my->last_processed_remote_head )
+            continue;
+
+         sync_with_trusted_node();
+         my->last_processed_remote_head = my->last_received_remote_head;
+      }
+      catch( const fc::exception& e )
+      {
+         elog("Error during connection: ${e}", ("e", e.to_detail_string()));
+      }
    }
 }
 
 void delayed_node_plugin::plugin_startup()
 {
-   try {
+   fc::async([this]()
+   {
+      mainloop();
+   });
+
+   try
+   {
       connect();
-
+      my->database_api->set_block_applied_callback([this]( const fc::variant& block_id )
-      my->database_api->set_subscribe_callback([this] (const fc::variant& v) {
-         auto& updates = v.get_array();
-         for( const auto& v : updates )
       {
-            if( v.is_object() )
+         fc::from_variant( block_id, my->last_received_remote_head );
-            {
+      } );
-               auto& obj = v.get_object();
-               if( obj["id"].as<graphene::chain::object_id_type>() == graphene::chain::dynamic_global_property_id_type() )
-               {
-                  auto props = v.as<graphene::chain::dynamic_global_property_object>();
-                  sync_with_trusted_node(props.head_block_number);
-               }
-            }
-         }
-      }, true);
-
-      // Go ahead and get in sync now, before subscribing
-      chain::dynamic_global_property_object props = my->database_api->get_dynamic_global_properties();
-      sync_with_trusted_node(props.head_block_number);
-
       return;
-   } catch (const fc::exception& e) {
+   }
+   catch (const fc::exception& e)
+   {
       elog("Error during connection: ${e}", ("e", e.to_detail_string()));
    }
    fc::async([this]{connection_failed();});
@@ -130,7 +150,7 @@ void delayed_node_plugin::plugin_startup()
 void delayed_node_plugin::connection_failed()
 {
    elog("Connection to trusted node failed; retrying in 5 seconds...");
-   fc::schedule([this]{plugin_startup();}, fc::time_point::now() + fc::seconds(5));
+   fc::schedule([this]{connect();}, fc::time_point::now() + fc::seconds(5));
 }
 
 } }

libraries/plugins/delayed_node/include/graphene/delayed_node/delayed_node_plugin.hpp

@@ -34,11 +34,12 @@ public:
                                            boost::program_options::options_description& cfg) override;
    virtual void plugin_initialize(const boost::program_options::variables_map& options) override;
    virtual void plugin_startup() override;
+   void mainloop();
 
 protected:
    void connection_failed();
    void connect();
-   void sync_with_trusted_node(uint32_t remote_head_block_num);
+   void sync_with_trusted_node();
 };
 
 } } //graphene::account_history