Merge pull request #7172 from EOSIO/create-snapshot-in-irreversible-mode

immediately return created snapshot in irreversible mode

plugins/producer_plugin/producer_plugin.cpp

@@ -1023,15 +1023,59 @@ void producer_plugin::create_snapshot(producer_plugin::next_function<producer_pl
    chain::controller& chain = my->chain_plug->chain();
 
    auto head_id = chain.head_block_id();
-   std::string snapshot_path = (pending_snapshot::get_final_path(head_id, my->_snapshots_dir)).generic_string();
+   const auto& snapshot_path = pending_snapshot::get_final_path(head_id, my->_snapshots_dir);
+   const auto& temp_path     = pending_snapshot::get_temp_path(head_id, my->_snapshots_dir);
 
    // maintain legacy exception if the snapshot exists
    if( fc::is_regular_file(snapshot_path) ) {
-      auto ex = snapshot_exists_exception( FC_LOG_MESSAGE( error, "snapshot named ${name} already exists", ("name", snapshot_path) ) );
+      auto ex = snapshot_exists_exception( FC_LOG_MESSAGE( error, "snapshot named ${name} already exists", ("name", snapshot_path.generic_string()) ) );
       next(ex.dynamic_copy_exception());
       return;
    }
 
+   auto write_snapshot = [&]( const bfs::path& p ) -> void {
+      auto reschedule = fc::make_scoped_exit([this](){
+         my->schedule_production_loop();
+      });
+
+      if (chain.is_building_block()) {
+         // abort the pending block
+         chain.abort_block();
+      } else {
+         reschedule.cancel();
+      }
+
+      bfs::create_directory( p.parent_path() );
+
+      // create the snapshot
+      auto snap_out = std::ofstream(p.generic_string(), (std::ios::out | std::ios::binary));
+      auto writer = std::make_shared<ostream_snapshot_writer>(snap_out);
+      chain.write_snapshot(writer);
+      writer->finalize();
+      snap_out.flush();
+      snap_out.close();
+   };
+
+   // If in irreversible mode, create snapshot and return path to snapshot immediately.
+   if( chain.get_read_mode() == db_read_mode::IRREVERSIBLE ) {
+      try {
+         write_snapshot( temp_path );
+
+         boost::system::error_code ec;
+         bfs::rename(temp_path, snapshot_path, ec);
+         EOS_ASSERT(!ec, snapshot_finalization_exception,
+               "Unable to finalize valid snapshot of block number ${bn}: [code: ${ec}] ${message}",
+               ("bn", chain.head_block_num())
+               ("ec", ec.value())
+               ("message", ec.message()));
+
+         next( producer_plugin::snapshot_information{head_id, snapshot_path.generic_string()} );
+      } CATCH_AND_CALL (next);
+      return;
+   }
+
+   // Otherwise, the result will be returned when the snapshot becomes irreversible.
+
    // determine if this snapshot is already in-flight
    auto& pending_by_id = my->_pending_snapshot_index.get<by_id>();
    auto existing = pending_by_id.find(head_id);
@@ -1044,31 +1088,10 @@ void producer_plugin::create_snapshot(producer_plugin::next_function<producer_pl
          };
       });
    } else {
-      // write a new temp snapshot
-      std::string temp_path = (pending_snapshot::get_temp_path(head_id, my->_snapshots_dir)).generic_string();
-      std::string pending_path = (pending_snapshot::get_pending_path(head_id, my->_snapshots_dir)).generic_string();
-      std::string final_path = (pending_snapshot::get_final_path(head_id, my->_snapshots_dir)).generic_string();
-      bool written = false;
+      const auto& pending_path = pending_snapshot::get_pending_path(head_id, my->_snapshots_dir);
 
       try {
-         auto reschedule = fc::make_scoped_exit([this](){
-            my->schedule_production_loop();
-         });
-
-         if (chain.is_building_block()) {
-            // abort the pending block
-            chain.abort_block();
-         } else {
-            reschedule.cancel();
-         }
-
-         // create a new pending snapshot
-         auto snap_out = std::ofstream(temp_path, (std::ios::out | std::ios::binary));
-         auto writer = std::make_shared<ostream_snapshot_writer>(snap_out);
-         chain.write_snapshot(writer);
-         writer->finalize();
-         snap_out.flush();
-         snap_out.close();
+         write_snapshot( temp_path ); // create a new pending snapshot
 
          boost::system::error_code ec;
          bfs::rename(temp_path, pending_path, ec);
@@ -1078,7 +1101,7 @@ void producer_plugin::create_snapshot(producer_plugin::next_function<producer_pl
                ("ec", ec.value())
                ("message", ec.message()));
 
-         my->_pending_snapshot_index.emplace(head_id, next, pending_path, final_path);
+         my->_pending_snapshot_index.emplace(head_id, next, pending_path.generic_string(), snapshot_path.generic_string());
       } CATCH_AND_CALL (next);
    }
 }