peerplays_migrated/libraries/plugins/delayed_node/delayed_node_plugin.cpp

/*
 * Copyright (c) 2015, Cryptonomex, Inc.
 * All rights reserved.
 *
 * This source code is provided for evaluation in private test networks only, until September 8, 2015. After this date, this license expires and
 * the code may not be used, modified or distributed for any purpose. Redistribution and use in source and binary forms, with or without modification,
 * are permitted until September 8, 2015, provided that the following conditions are met:
 *
 * 1. The code and/or derivative works are used only for private test networks consisting of no more than 10 P2P nodes.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <graphene/delayed_node/delayed_node_plugin.hpp>
#include <graphene/chain/protocol/types.hpp>
#include <graphene/chain/database.hpp>
#include <graphene/app/api.hpp>

#include <fc/network/http/websocket.hpp>
#include <fc/rpc/websocket_api.hpp>
#include <fc/api.hpp>
#include <fc/smart_ref_impl.hpp>


namespace graphene { namespace delayed_node {
namespace bpo = boost::program_options;

namespace detail {
struct delayed_node_plugin_impl {
   std::string remote_endpoint;
   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;
   graphene::chain::block_id_type last_received_remote_head;
   graphene::chain::block_id_type last_processed_remote_head;
};
}

delayed_node_plugin::delayed_node_plugin()
   : my(new detail::delayed_node_plugin_impl)
{}

delayed_node_plugin::~delayed_node_plugin()
{}

void delayed_node_plugin::plugin_set_program_options(bpo::options_description& cli, bpo::options_description& cfg)
{
   cli.add_options()
         ("trusted-node", boost::program_options::value<std::string>()->required(), "RPC endpoint of a trusted validating node (required)")
         ;
   cfg.add(cli);
}

void delayed_node_plugin::connect()
{
   my->client_connection = std::make_shared<fc::rpc::websocket_api_connection>(*my->client.connect(my->remote_endpoint));
   my->database_api = my->client_connection->get_remote_api<graphene::app::database_api>(0);
   my->client_connection_closed = my->client_connection->closed.connect([this] {
      connection_failed();
   });
}

void delayed_node_plugin::plugin_initialize(const boost::program_options::variables_map& options)
{
   my->remote_endpoint = "ws://" + options.at("trusted-node").as<std::string>();
}

void delayed_node_plugin::sync_with_trusted_node()
{
   auto& db = database();
   uint32_t synced_blocks = 0;
   uint32_t pass_count = 0;
   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 )
         {
            ilog( "Delayed node finished syncing ${n} blocks in ${k} passes", ("n", synced_blocks)("k", pass_count) );
         }
         break;
      }
      pass_count++;
      while( remote_dpo.last_irreversible_block_num > db.head_block_num() )
      {
         fc::optional<graphene::chain::signed_block> block = my->database_api->get_block( db.head_block_num()+1 );
         FC_ASSERT(block, "Trusted node claims it has blocks it doesn't actually have.");
         ilog("Pushing block #${n}", ("n", block->block_num()));
         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()
{
   fc::async([this]()
   {
      mainloop();
   });

   try
   {
      connect();
      my->database_api->set_block_applied_callback([this]( const fc::variant& block_id )
      {
         fc::from_variant( block_id, my->last_received_remote_head );
      } );
      return;
   }
   catch (const fc::exception& e)
   {
      elog("Error during connection: ${e}", ("e", e.to_detail_string()));
   }
   fc::async([this]{connection_failed();});
}

void delayed_node_plugin::connection_failed()
{
   elog("Connection to trusted node failed; retrying in 5 seconds...");
   fc::schedule([this]{connect();}, fc::time_point::now() + fc::seconds(5));
}

} }