Remove payload copy in all outgoing p2p messages

src/cryptonote_protocol/cryptonote_protocol_handler.h

@@ -46,6 +46,8 @@
 #include "block_queue.h"
 #include "common/perf_timer.h"
 #include "cryptonote_basic/connection_context.h"
+#include "net/levin_base.h"
+#include "p2p/net_node_common.h"
 #include <boost/circular_buffer.hpp>
 
 PUSH_WARNINGS
@@ -195,10 +197,11 @@ namespace cryptonote
       bool post_notify(typename t_parameter::request& arg, cryptonote_connection_context& context)
       {
         LOG_PRINT_L2("[" << epee::net_utils::print_connection_context_short(context) << "] post " << typeid(t_parameter).name() << " -->");
-        epee::byte_slice blob;
-        epee::serialization::store_t_to_binary(arg, blob, 256 * 1024); // optimize for block responses
+
+        epee::levin::message_writer out{256 * 1024}; // optimize for block responses
+        epee::serialization::store_t_to_binary(arg, out.buffer);
         //handler_response_blocks_now(blob.size()); // XXX
-        return m_p2p->invoke_notify_to_peer(t_parameter::ID, epee::to_span(blob), context);
+        return m_p2p->invoke_notify_to_peer(t_parameter::ID, std::move(out), context);
       }
   };
 

src/cryptonote_protocol/cryptonote_protocol_handler.inl

@@ -2699,15 +2699,15 @@ skip:
     // send fluffy ones first, we want to encourage people to run that
     if (!fluffyConnections.empty())
     {
-      epee::byte_slice fluffyBlob;
-      epee::serialization::store_t_to_binary(fluffy_arg, fluffyBlob, 32 * 1024);
-      m_p2p->relay_notify_to_list(NOTIFY_NEW_FLUFFY_BLOCK::ID, epee::to_span(fluffyBlob), std::move(fluffyConnections));
+      epee::levin::message_writer fluffyBlob{32 * 1024};
+      epee::serialization::store_t_to_binary(fluffy_arg, fluffyBlob.buffer);
+      m_p2p->relay_notify_to_list(NOTIFY_NEW_FLUFFY_BLOCK::ID, std::move(fluffyBlob), std::move(fluffyConnections));
     }
     if (!fullConnections.empty())
     {
-      epee::byte_slice fullBlob;
-      epee::serialization::store_t_to_binary(arg, fullBlob, 128 * 1024);
-      m_p2p->relay_notify_to_list(NOTIFY_NEW_BLOCK::ID, epee::to_span(fullBlob), std::move(fullConnections));
+      epee::levin::message_writer fullBlob{128 * 1024};
+      epee::serialization::store_t_to_binary(arg, fullBlob.buffer);
+      m_p2p->relay_notify_to_list(NOTIFY_NEW_BLOCK::ID, std::move(fullBlob), std::move(fullConnections));
     }
 
     return true;

src/cryptonote_protocol/cryptonote_protocol_handler_common.h

@@ -30,8 +30,8 @@
 
 #pragma once
 
-#include "p2p/net_node_common.h"
 #include "cryptonote_protocol/cryptonote_protocol_defs.h"
+#include "cryptonote_protocol/enums.h"
 #include "cryptonote_basic/connection_context.h"
 namespace cryptonote
 {

src/cryptonote_protocol/levin_notify.cpp

@@ -159,7 +159,7 @@ namespace levin
       return get_out_connections(p2p, get_blockchain_height(p2p, core));
     }
 
-    epee::byte_slice make_tx_payload(std::vector<blobdata>&& txs, const bool pad, const bool fluff)
+    epee::levin::message_writer make_tx_message(std::vector<blobdata>&& txs, const bool pad, const bool fluff)
     {
       NOTIFY_NEW_TRANSACTIONS::request request{};
       request.txs = std::move(txs);
@@ -193,21 +193,17 @@ namespace levin
         // if the size of _ moved enough, we might lose byte in size encoding, we don't care
       }
 
-      epee::byte_slice fullBlob;
-      if (!epee::serialization::store_t_to_binary(request, fullBlob))
+      epee::levin::message_writer out;
+      if (!epee::serialization::store_t_to_binary(request, out.buffer))
         throw std::runtime_error{"Failed to serialize to epee binary format"};
 
-      return fullBlob;
+      return out;
     }
 
     bool make_payload_send_txs(connections& p2p, std::vector<blobdata>&& txs, const boost::uuids::uuid& destination, const bool pad, const bool fluff)
     {
-      const epee::byte_slice blob = make_tx_payload(std::move(txs), pad, fluff);
-      p2p.for_connection(destination, [&blob](detail::p2p_context& context) {
-        on_levin_traffic(context, true, true, false, blob.size(), NOTIFY_NEW_TRANSACTIONS::ID);
-        return true;
-      });
-      return p2p.notify(NOTIFY_NEW_TRANSACTIONS::ID, epee::to_span(blob), destination);
+      epee::byte_slice blob = make_tx_message(std::move(txs), pad, fluff).finalize_notify(NOTIFY_NEW_TRANSACTIONS::ID);
+      return p2p.send(std::move(blob), destination);
     }
 
     /* The current design uses `asio::strand`s. The documentation isn't as clear
@@ -653,10 +649,6 @@ namespace levin
           else
             message = zone_->noise.clone();
 
-          zone_->p2p->for_connection(channel.connection, [&](detail::p2p_context& context) {
-            on_levin_traffic(context, true, true, false, message.size(), "noise");
-            return true;
-          });
           if (zone_->p2p->send(std::move(message), channel.connection))
           {
             if (!channel.queue.empty() && channel.active.empty())
@@ -816,9 +808,8 @@ namespace levin
 
       // Padding is not useful when using noise mode. Send as stem so receiver
       // forwards in Dandelion++ mode.
-      const epee::byte_slice payload = make_tx_payload(std::move(txs), false, false);
       epee::byte_slice message = epee::levin::make_fragmented_notify(
-        zone_->noise, NOTIFY_NEW_TRANSACTIONS::ID, epee::to_span(payload)
+        zone_->noise.size(), NOTIFY_NEW_TRANSACTIONS::ID, make_tx_message(std::move(txs), false, false)
       );
       if (CRYPTONOTE_MAX_FRAGMENTS * zone_->noise.size() < message.size())
       {