Various improvements to the ZMQ JSON-RPC handling:

  - Finding handling function in ZMQ JSON-RPC now uses binary search
  - Temporary `std::vector`s in JSON output now use `epee::span` to
    prevent allocations.
  - Binary -> hex in JSON output no longer allocates temporary buffer
  - C++ structs -> JSON skips intermediate DOM creation, and instead
    write directly to an output stream.

6 files changed, 353 insertions, 650 deletions

diff --git a/src/rpc/daemon_handler.cpp b/src/rpc/daemon_handler.cpp
index 0b6cd6c7a..7c2bc4562 100644
--- a/src/rpc/daemon_handler.cpp
+++ b/src/rpc/daemon_handler.cpp
@@ -28,6 +28,10 @@
 
 #include "daemon_handler.h"
 
+#include <algorithm>
+#include <cstring>
+#include <stdexcept>
+
 #include <boost/uuid/nil_generator.hpp>
 // likely included by daemon_handler.h's includes,
 // but including here for clarity
@@ -42,6 +46,74 @@ namespace cryptonote
 
 namespace rpc
 {
+  namespace
+  {
+    using handler_function = std::string(DaemonHandler& handler, const rapidjson::Value& id, const rapidjson::Value& msg);
+    struct handler_map
+    {
+      const char* method_name;
+      handler_function* call;
+    };
+
+    bool operator<(const handler_map& lhs, const handler_map& rhs) noexcept
+    {
+      return std::strcmp(lhs.method_name, rhs.method_name) < 0;
+    }
+
+    bool operator<(const handler_map& lhs, const std::string& rhs) noexcept
+    {
+      return std::strcmp(lhs.method_name, rhs.c_str()) < 0;
+    }
+
+    template<typename Message>
+    std::string handle_message(DaemonHandler& handler, const rapidjson::Value& id, const rapidjson::Value& parameters)
+    {
+      typename Message::Request request{};
+      request.fromJson(parameters);
+
+      typename Message::Response response{};
+      handler.handle(request, response);
+      return FullMessage::getResponse(response, id);
+    }
+
+    constexpr const handler_map handlers[] =
+    {
+      {u8"get_block_hash", handle_message<GetBlockHash>},
+      {u8"get_block_header_by_hash", handle_message<GetBlockHeaderByHash>},
+      {u8"get_block_header_by_height", handle_message<GetBlockHeaderByHeight>},
+      {u8"get_block_headers_by_height", handle_message<GetBlockHeadersByHeight>},
+      {u8"get_blocks_fast", handle_message<GetBlocksFast>},
+      {u8"get_dynamic_fee_estimate", handle_message<GetFeeEstimate>},
+      {u8"get_hashes_fast", handle_message<GetHashesFast>},
+      {u8"get_height", handle_message<GetHeight>},
+      {u8"get_info", handle_message<GetInfo>},
+      {u8"get_last_block_header", handle_message<GetLastBlockHeader>},
+      {u8"get_output_distribution", handle_message<GetOutputDistribution>},
+      {u8"get_output_histogram", handle_message<GetOutputHistogram>},
+      {u8"get_output_keys", handle_message<GetOutputKeys>},
+      {u8"get_peer_list", handle_message<GetPeerList>},
+      {u8"get_rpc_version", handle_message<GetRPCVersion>},
+      {u8"get_transaction_pool", handle_message<GetTransactionPool>},
+      {u8"get_transactions", handle_message<GetTransactions>},
+      {u8"get_tx_global_output_indices", handle_message<GetTxGlobalOutputIndices>},
+      {u8"hard_fork_info", handle_message<HardForkInfo>},
+      {u8"key_images_spent", handle_message<KeyImagesSpent>},
+      {u8"mining_status", handle_message<MiningStatus>},
+      {u8"save_bc", handle_message<SaveBC>},
+      {u8"send_raw_tx", handle_message<SendRawTxHex>},
+      {u8"set_log_level", handle_message<SetLogLevel>},
+      {u8"start_mining", handle_message<StartMining>},
+      {u8"stop_mining", handle_message<StopMining>}
+    };
+  } // anonymous
+
+  DaemonHandler::DaemonHandler(cryptonote::core& c, t_p2p& p2p)
+    : m_core(c), m_p2p(p2p)
+  {
+    const auto last_sorted = std::is_sorted_until(std::begin(handlers), std::end(handlers));
+    if (last_sorted != std::end(handlers))
+      throw std::logic_error{std::string{"ZMQ JSON-RPC handlers map is not properly sorted, see "} + last_sorted->method_name};
+  }
 
   void DaemonHandler::handle(const GetHeight::Request& req, GetHeight::Response& res)
   {
@@ -840,68 +912,21 @@ namespace rpc
   {
     MDEBUG("Handling RPC request: " << request);
 
-    Message* resp_message = NULL;
-
     try
     {
       FullMessage req_full(request, true);
 
-      rapidjson::Value& req_json = req_full.getMessage();
-
       const std::string request_type = req_full.getRequestType();
-
-      // create correct Message subclass and call handle() on it
-      REQ_RESP_TYPES_MACRO(request_type, GetHeight, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetBlocksFast, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetHashesFast, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetTransactions, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, KeyImagesSpent, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetTxGlobalOutputIndices, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, SendRawTx, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, SendRawTxHex, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetInfo, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, StartMining, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, StopMining, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, MiningStatus, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, SaveBC, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetBlockHash, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetLastBlockHeader, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetBlockHeaderByHash, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetBlockHeaderByHeight, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetBlockHeadersByHeight, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetPeerList, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, SetLogLevel, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetTransactionPool, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, HardForkInfo, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetOutputHistogram, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetOutputKeys, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetRPCVersion, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetFeeEstimate, req_json, resp_message, handle);
-      REQ_RESP_TYPES_MACRO(request_type, GetOutputDistribution, req_json, resp_message, handle);
-
-      // if none of the request types matches
-      if (resp_message == NULL)
-      {
+      const auto matched_handler = std::lower_bound(std::begin(handlers), std::end(handlers), request_type);
+      if (matched_handler == std::end(handlers) || matched_handler->method_name != request_type)
         return BAD_REQUEST(request_type, req_full.getID());
-      }
-
-      FullMessage resp_full = FullMessage::responseMessage(resp_message, req_full.getID());
-
-      const std::string response = resp_full.getJson();
-      delete resp_message;
-      resp_message = NULL;
 
+      std::string response = matched_handler->call(*this, req_full.getID(), req_full.getMessage());
       MDEBUG("Returning RPC response: " << response);
-
       return response;
     }
     catch (const std::exception& e)
     {
-      if (resp_message)
-      {
-        delete resp_message;
-      }
-
       return BAD_JSON(e.what());
     }
   }
diff --git a/src/rpc/daemon_handler.h b/src/rpc/daemon_handler.h
index 34723f676..c33f608ab 100644
--- a/src/rpc/daemon_handler.h
+++ b/src/rpc/daemon_handler.h
@@ -50,7 +50,7 @@ class DaemonHandler : public RpcHandler
 {
   public:
 
-    DaemonHandler(cryptonote::core& c, t_p2p& p2p) : m_core(c), m_p2p(p2p) { }
+    DaemonHandler(cryptonote::core& c, t_p2p& p2p);
 
     ~DaemonHandler() { }
 
diff --git a/src/rpc/daemon_messages.cpp b/src/rpc/daemon_messages.cpp
index cf0f5ece1..5c179408e 100644
--- a/src/rpc/daemon_messages.cpp
+++ b/src/rpc/daemon_messages.cpp
@@ -34,99 +34,47 @@ namespace cryptonote
 
 namespace rpc
 {
+void GetHeight::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-const char* const GetHeight::name = "get_height";
-const char* const GetBlocksFast::name = "get_blocks_fast";
-const char* const GetHashesFast::name = "get_hashes_fast";
-const char* const GetTransactions::name = "get_transactions";
-const char* const KeyImagesSpent::name = "key_images_spent";
-const char* const GetTxGlobalOutputIndices::name = "get_tx_global_output_indices";
-const char* const SendRawTx::name = "send_raw_tx";
-const char* const SendRawTxHex::name = "send_raw_tx_hex";
-const char* const StartMining::name = "start_mining";
-const char* const StopMining::name = "stop_mining";
-const char* const MiningStatus::name = "mining_status";
-const char* const GetInfo::name = "get_info";
-const char* const SaveBC::name = "save_bc";
-const char* const GetBlockHash::name = "get_block_hash";
-const char* const GetLastBlockHeader::name = "get_last_block_header";
-const char* const GetBlockHeaderByHash::name = "get_block_header_by_hash";
-const char* const GetBlockHeaderByHeight::name = "get_block_header_by_height";
-const char* const GetBlockHeadersByHeight::name = "get_block_headers_by_height";
-const char* const GetPeerList::name = "get_peer_list";
-const char* const SetLogLevel::name = "set_log_level";
-const char* const GetTransactionPool::name = "get_transaction_pool";
-const char* const HardForkInfo::name = "hard_fork_info";
-const char* const GetOutputHistogram::name = "get_output_histogram";
-const char* const GetOutputKeys::name = "get_output_keys";
-const char* const GetRPCVersion::name = "get_rpc_version";
-const char* const GetFeeEstimate::name = "get_dynamic_fee_estimate";
-const char* const GetOutputDistribution::name = "get_output_distribution";
-
-
-
-
-rapidjson::Value GetHeight::Request::toJson(rapidjson::Document& doc) const
+void GetHeight::Request::fromJson(const rapidjson::Value& val)
 {
-  return Message::toJson(doc);
 }
 
-void GetHeight::Request::fromJson(rapidjson::Value& val)
+void GetHeight::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
+  INSERT_INTO_JSON_OBJECT(dest, height, height);
 }
 
-rapidjson::Value GetHeight::Response::toJson(rapidjson::Document& doc) const
-{
-  auto val = Message::toJson(doc);
-
-  auto& al = doc.GetAllocator();
-
-  val.AddMember("height", height, al);
-
-  return val;
-}
-
-void GetHeight::Response::fromJson(rapidjson::Value& val)
+void GetHeight::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, height, height);
 }
 
 
-rapidjson::Value GetBlocksFast::Request::toJson(rapidjson::Document& doc) const
+void GetBlocksFast::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  auto& al = doc.GetAllocator();
-
-  INSERT_INTO_JSON_OBJECT(val, doc, block_ids, block_ids);
-  val.AddMember("start_height", start_height, al);
-  val.AddMember("prune", prune, al);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, block_ids, block_ids);
+  INSERT_INTO_JSON_OBJECT(dest, start_height, start_height);
+  INSERT_INTO_JSON_OBJECT(dest, prune, prune);
 }
 
-void GetBlocksFast::Request::fromJson(rapidjson::Value& val)
+void GetBlocksFast::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, block_ids, block_ids);
   GET_FROM_JSON_OBJECT(val, start_height, start_height);
   GET_FROM_JSON_OBJECT(val, prune, prune);
 }
 
-rapidjson::Value GetBlocksFast::Response::toJson(rapidjson::Document& doc) const
+void GetBlocksFast::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  auto& al = doc.GetAllocator();
-
-  INSERT_INTO_JSON_OBJECT(val, doc, blocks, blocks);
-  val.AddMember("start_height", start_height, al);
-  val.AddMember("current_height", current_height, al);
-  INSERT_INTO_JSON_OBJECT(val, doc, output_indices, output_indices);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, blocks, blocks);
+  INSERT_INTO_JSON_OBJECT(dest, start_height, start_height);
+  INSERT_INTO_JSON_OBJECT(dest, current_height, current_height);
+  INSERT_INTO_JSON_OBJECT(dest, output_indices, output_indices);
 }
 
-void GetBlocksFast::Response::fromJson(rapidjson::Value& val)
+void GetBlocksFast::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, blocks, blocks);
   GET_FROM_JSON_OBJECT(val, start_height, start_height);
@@ -135,38 +83,26 @@ void GetBlocksFast::Response::fromJson(rapidjson::Value& val)
 }
 
 
-rapidjson::Value GetHashesFast::Request::toJson(rapidjson::Document& doc) const
+void GetHashesFast::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  auto& al = doc.GetAllocator();
-
-  INSERT_INTO_JSON_OBJECT(val, doc, known_hashes, known_hashes);
-  val.AddMember("start_height", start_height, al);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, known_hashes, known_hashes);
+  INSERT_INTO_JSON_OBJECT(dest, start_height, start_height);
 }
 
-void GetHashesFast::Request::fromJson(rapidjson::Value& val)
+void GetHashesFast::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, known_hashes, known_hashes);
   GET_FROM_JSON_OBJECT(val, start_height, start_height);
 }
 
-rapidjson::Value GetHashesFast::Response::toJson(rapidjson::Document& doc) const
+void GetHashesFast::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  auto& al = doc.GetAllocator();
-
-  INSERT_INTO_JSON_OBJECT(val, doc, hashes, hashes);
-  val.AddMember("start_height", start_height, al);
-  val.AddMember("current_height", current_height, al);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, hashes, hashes);
+  INSERT_INTO_JSON_OBJECT(dest, start_height, start_height);
+  INSERT_INTO_JSON_OBJECT(dest, current_height, current_height);
 }
 
-void GetHashesFast::Response::fromJson(rapidjson::Value& val)
+void GetHashesFast::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, hashes, hashes);
   GET_FROM_JSON_OBJECT(val, start_height, start_height);
@@ -174,154 +110,114 @@ void GetHashesFast::Response::fromJson(rapidjson::Value& val)
 }
 
 
-rapidjson::Value GetTransactions::Request::toJson(rapidjson::Document& doc) const
+void GetTransactions::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, tx_hashes, tx_hashes);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, tx_hashes, tx_hashes);
 }
 
-void GetTransactions::Request::fromJson(rapidjson::Value& val)
+void GetTransactions::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, tx_hashes, tx_hashes);
 }
 
-rapidjson::Value GetTransactions::Response::toJson(rapidjson::Document& doc) const
+void GetTransactions::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  rapidjson::Value val(rapidjson::kObjectType);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, txs, txs);
-  INSERT_INTO_JSON_OBJECT(val, doc, missed_hashes, missed_hashes);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, txs, txs);
+  INSERT_INTO_JSON_OBJECT(dest, missed_hashes, missed_hashes);
 }
 
-void GetTransactions::Response::fromJson(rapidjson::Value& val)
+void GetTransactions::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, txs, txs);
   GET_FROM_JSON_OBJECT(val, missed_hashes, missed_hashes);
 }
 
 
-rapidjson::Value KeyImagesSpent::Request::toJson(rapidjson::Document& doc) const
+void KeyImagesSpent::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, key_images, key_images);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, key_images, key_images);
 }
 
-void KeyImagesSpent::Request::fromJson(rapidjson::Value& val)
+void KeyImagesSpent::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, key_images, key_images);
 }
 
-rapidjson::Value KeyImagesSpent::Response::toJson(rapidjson::Document& doc) const
+void KeyImagesSpent::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, spent_status, spent_status);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, spent_status, spent_status);
 }
 
-void KeyImagesSpent::Response::fromJson(rapidjson::Value& val)
+void KeyImagesSpent::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, spent_status, spent_status);
 }
 
 
-rapidjson::Value GetTxGlobalOutputIndices::Request::toJson(rapidjson::Document& doc) const
+void GetTxGlobalOutputIndices::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, tx_hash, tx_hash);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, tx_hash, tx_hash);
 }
 
-void GetTxGlobalOutputIndices::Request::fromJson(rapidjson::Value& val)
+void GetTxGlobalOutputIndices::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, tx_hash, tx_hash);
 }
 
-rapidjson::Value GetTxGlobalOutputIndices::Response::toJson(rapidjson::Document& doc) const
+void GetTxGlobalOutputIndices::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, output_indices, output_indices);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, output_indices, output_indices);
 }
 
-void GetTxGlobalOutputIndices::Response::fromJson(rapidjson::Value& val)
+void GetTxGlobalOutputIndices::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, output_indices, output_indices);
 }
 
-rapidjson::Value SendRawTx::Request::toJson(rapidjson::Document& doc) const
+void SendRawTx::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, tx, tx);
-  INSERT_INTO_JSON_OBJECT(val, doc, relay, relay);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, tx, tx);
+  INSERT_INTO_JSON_OBJECT(dest, relay, relay);
 }
 
-void SendRawTx::Request::fromJson(rapidjson::Value& val)
+void SendRawTx::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, tx, tx);
   GET_FROM_JSON_OBJECT(val, relay, relay);
 }
 
-rapidjson::Value SendRawTx::Response::toJson(rapidjson::Document& doc) const
+void SendRawTx::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, relayed, relayed);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, relayed, relayed);
 }
 
 
-void SendRawTx::Response::fromJson(rapidjson::Value& val)
+void SendRawTx::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, relayed, relayed);
 }
 
-rapidjson::Value SendRawTxHex::Request::toJson(rapidjson::Document& doc) const
+void SendRawTxHex::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, tx_as_hex, tx_as_hex);
-  INSERT_INTO_JSON_OBJECT(val, doc, relay, relay);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, tx_as_hex, tx_as_hex);
+  INSERT_INTO_JSON_OBJECT(dest, relay, relay);
 }
 
-void SendRawTxHex::Request::fromJson(rapidjson::Value& val)
+void SendRawTxHex::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, tx_as_hex, tx_as_hex);
   GET_FROM_JSON_OBJECT(val, relay, relay);
 }
 
-rapidjson::Value StartMining::Request::toJson(rapidjson::Document& doc) const
+void StartMining::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, miner_address, miner_address);
-  INSERT_INTO_JSON_OBJECT(val, doc, threads_count, threads_count);
-  INSERT_INTO_JSON_OBJECT(val, doc, do_background_mining, do_background_mining);
-  INSERT_INTO_JSON_OBJECT(val, doc, ignore_battery, ignore_battery);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, miner_address, miner_address);
+  INSERT_INTO_JSON_OBJECT(dest, threads_count, threads_count);
+  INSERT_INTO_JSON_OBJECT(dest, do_background_mining, do_background_mining);
+  INSERT_INTO_JSON_OBJECT(dest, ignore_battery, ignore_battery);
 }
 
-void StartMining::Request::fromJson(rapidjson::Value& val)
+void StartMining::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, miner_address, miner_address);
   GET_FROM_JSON_OBJECT(val, threads_count, threads_count);
@@ -329,58 +225,46 @@ void StartMining::Request::fromJson(rapidjson::Value& val)
   GET_FROM_JSON_OBJECT(val, ignore_battery, ignore_battery);
 }
 
-rapidjson::Value StartMining::Response::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void StartMining::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void StartMining::Response::fromJson(rapidjson::Value& val)
+void StartMining::Response::fromJson(const rapidjson::Value& val)
 {
 }
 
 
-rapidjson::Value StopMining::Request::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void StopMining::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void StopMining::Request::fromJson(rapidjson::Value& val)
+void StopMining::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value StopMining::Response::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void StopMining::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void StopMining::Response::fromJson(rapidjson::Value& val)
+void StopMining::Response::fromJson(const rapidjson::Value& val)
 {
 }
 
 
-rapidjson::Value MiningStatus::Request::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void MiningStatus::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void MiningStatus::Request::fromJson(rapidjson::Value& val)
+void MiningStatus::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value MiningStatus::Response::toJson(rapidjson::Document& doc) const
+void MiningStatus::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, active, active);
-  INSERT_INTO_JSON_OBJECT(val, doc, speed, speed);
-  INSERT_INTO_JSON_OBJECT(val, doc, threads_count, threads_count);
-  INSERT_INTO_JSON_OBJECT(val, doc, address, address);
-  INSERT_INTO_JSON_OBJECT(val, doc, is_background_mining_enabled, is_background_mining_enabled);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, active, active);
+  INSERT_INTO_JSON_OBJECT(dest, speed, speed);
+  INSERT_INTO_JSON_OBJECT(dest, threads_count, threads_count);
+  INSERT_INTO_JSON_OBJECT(dest, address, address);
+  INSERT_INTO_JSON_OBJECT(dest, is_background_mining_enabled, is_background_mining_enabled);
 }
 
-void MiningStatus::Response::fromJson(rapidjson::Value& val)
+void MiningStatus::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, active, active);
   GET_FROM_JSON_OBJECT(val, speed, speed);
@@ -390,318 +274,230 @@ void MiningStatus::Response::fromJson(rapidjson::Value& val)
 }
 
 
-rapidjson::Value GetInfo::Request::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void GetInfo::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void GetInfo::Request::fromJson(rapidjson::Value& val)
+void GetInfo::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value GetInfo::Response::toJson(rapidjson::Document& doc) const
+void GetInfo::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, info, info);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, info, info);
 }
 
-void GetInfo::Response::fromJson(rapidjson::Value& val)
+void GetInfo::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, info, info);
 }
 
 
-rapidjson::Value SaveBC::Request::toJson(rapidjson::Document& doc) const
-{
-  auto val = Message::toJson(doc);
+void SaveBC::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-  return val;
-}
-
-void SaveBC::Request::fromJson(rapidjson::Value& val)
+void SaveBC::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value SaveBC::Response::toJson(rapidjson::Document& doc) const
-{
-  auto val = Message::toJson(doc);
+void SaveBC::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-  return val;
-}
-
-void SaveBC::Response::fromJson(rapidjson::Value& val)
+void SaveBC::Response::fromJson(const rapidjson::Value& val)
 {
 }
 
 
-rapidjson::Value GetBlockHash::Request::toJson(rapidjson::Document& doc) const
+void GetBlockHash::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, height, height);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, height, height);
 }
 
-void GetBlockHash::Request::fromJson(rapidjson::Value& val)
+void GetBlockHash::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, height, height);
 }
 
-rapidjson::Value GetBlockHash::Response::toJson(rapidjson::Document& doc) const
+void GetBlockHash::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, hash, hash);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, hash, hash);
 }
 
-void GetBlockHash::Response::fromJson(rapidjson::Value& val)
+void GetBlockHash::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, hash, hash);
 }
 
 
-rapidjson::Value GetLastBlockHeader::Request::toJson(rapidjson::Document& doc) const
-{
-  auto val = Message::toJson(doc);
-
-  return val;
-}
+void GetLastBlockHeader::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void GetLastBlockHeader::Request::fromJson(rapidjson::Value& val)
+void GetLastBlockHeader::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value GetLastBlockHeader::Response::toJson(rapidjson::Document& doc) const
+void GetLastBlockHeader::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, header, header);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, header, header);
 }
 
-void GetLastBlockHeader::Response::fromJson(rapidjson::Value& val)
+void GetLastBlockHeader::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, header, header);
 }
 
 
-rapidjson::Value GetBlockHeaderByHash::Request::toJson(rapidjson::Document& doc) const
+void GetBlockHeaderByHash::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, hash, hash);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, hash, hash);
 }
 
-void GetBlockHeaderByHash::Request::fromJson(rapidjson::Value& val)
+void GetBlockHeaderByHash::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, hash, hash);
 }
 
-rapidjson::Value GetBlockHeaderByHash::Response::toJson(rapidjson::Document& doc) const
+void GetBlockHeaderByHash::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, header, header);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, header, header);
 }
 
-void GetBlockHeaderByHash::Response::fromJson(rapidjson::Value& val)
+void GetBlockHeaderByHash::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, header, header);
 }
 
 
-rapidjson::Value GetBlockHeaderByHeight::Request::toJson(rapidjson::Document& doc) const
+void GetBlockHeaderByHeight::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, height, height);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, height, height);
 }
 
-void GetBlockHeaderByHeight::Request::fromJson(rapidjson::Value& val)
+void GetBlockHeaderByHeight::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, height, height);
 }
 
-rapidjson::Value GetBlockHeaderByHeight::Response::toJson(rapidjson::Document& doc) const
+void GetBlockHeaderByHeight::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, header, header);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, header, header);
 }
 
-void GetBlockHeaderByHeight::Response::fromJson(rapidjson::Value& val)
+void GetBlockHeaderByHeight::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, header, header);
 }
 
 
-rapidjson::Value GetBlockHeadersByHeight::Request::toJson(rapidjson::Document& doc) const
+void GetBlockHeadersByHeight::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, heights, heights);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, heights, heights);
 }
 
-void GetBlockHeadersByHeight::Request::fromJson(rapidjson::Value& val)
+void GetBlockHeadersByHeight::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, heights, heights);
 }
 
-rapidjson::Value GetBlockHeadersByHeight::Response::toJson(rapidjson::Document& doc) const
+void GetBlockHeadersByHeight::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, headers, headers);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, headers, headers);
 }
 
-void GetBlockHeadersByHeight::Response::fromJson(rapidjson::Value& val)
+void GetBlockHeadersByHeight::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, headers, headers);
 }
 
 
-rapidjson::Value GetPeerList::Request::toJson(rapidjson::Document& doc) const
-{
-  auto val = Message::toJson(doc);
+void GetPeerList::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-  return val;
-}
-
-void GetPeerList::Request::fromJson(rapidjson::Value& val)
+void GetPeerList::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value GetPeerList::Response::toJson(rapidjson::Document& doc) const
+void GetPeerList::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, white_list, white_list);
-  INSERT_INTO_JSON_OBJECT(val, doc, gray_list, gray_list);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, white_list, white_list);
+  INSERT_INTO_JSON_OBJECT(dest, gray_list, gray_list);
 }
 
-void GetPeerList::Response::fromJson(rapidjson::Value& val)
+void GetPeerList::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, white_list, white_list);
   GET_FROM_JSON_OBJECT(val, gray_list, gray_list);
 }
 
 
-rapidjson::Value SetLogLevel::Request::toJson(rapidjson::Document& doc) const
+void SetLogLevel::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  auto& al = doc.GetAllocator();
-
-  val.AddMember("level", level, al);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, level, level);
 }
 
-void SetLogLevel::Request::fromJson(rapidjson::Value& val)
+void SetLogLevel::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, level, level);
 }
 
-rapidjson::Value SetLogLevel::Response::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void SetLogLevel::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void SetLogLevel::Response::fromJson(rapidjson::Value& val)
+void SetLogLevel::Response::fromJson(const rapidjson::Value& val)
 {
 }
 
 
-rapidjson::Value GetTransactionPool::Request::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void GetTransactionPool::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void GetTransactionPool::Request::fromJson(rapidjson::Value& val)
+void GetTransactionPool::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value GetTransactionPool::Response::toJson(rapidjson::Document& doc) const
+void GetTransactionPool::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, transactions, transactions);
-  INSERT_INTO_JSON_OBJECT(val, doc, key_images, key_images);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, transactions, transactions);
+  INSERT_INTO_JSON_OBJECT(dest, key_images, key_images);
 }
 
-void GetTransactionPool::Response::fromJson(rapidjson::Value& val)
+void GetTransactionPool::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, transactions, transactions);
   GET_FROM_JSON_OBJECT(val, key_images, key_images);
 }
 
 
-rapidjson::Value HardForkInfo::Request::toJson(rapidjson::Document& doc) const
+void HardForkInfo::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, version, version);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, version, version);
 }
 
-void HardForkInfo::Request::fromJson(rapidjson::Value& val)
+void HardForkInfo::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, version, version);
 }
 
-rapidjson::Value HardForkInfo::Response::toJson(rapidjson::Document& doc) const
+void HardForkInfo::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, info, info);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, info, info);
 }
 
-void HardForkInfo::Response::fromJson(rapidjson::Value& val)
+void HardForkInfo::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, info, info);
 }
 
 
-rapidjson::Value GetOutputHistogram::Request::toJson(rapidjson::Document& doc) const
+void GetOutputHistogram::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, amounts, amounts);
-  INSERT_INTO_JSON_OBJECT(val, doc, min_count, min_count);
-  INSERT_INTO_JSON_OBJECT(val, doc, max_count, max_count);
-  INSERT_INTO_JSON_OBJECT(val, doc, unlocked, unlocked);
-  INSERT_INTO_JSON_OBJECT(val, doc, recent_cutoff, recent_cutoff);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, amounts, amounts);
+  INSERT_INTO_JSON_OBJECT(dest, min_count, min_count);
+  INSERT_INTO_JSON_OBJECT(dest, max_count, max_count);
+  INSERT_INTO_JSON_OBJECT(dest, unlocked, unlocked);
+  INSERT_INTO_JSON_OBJECT(dest, recent_cutoff, recent_cutoff);
 }
 
-void GetOutputHistogram::Request::fromJson(rapidjson::Value& val)
+void GetOutputHistogram::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, amounts, amounts);
   GET_FROM_JSON_OBJECT(val, min_count, min_count);
@@ -710,100 +506,74 @@ void GetOutputHistogram::Request::fromJson(rapidjson::Value& val)
   GET_FROM_JSON_OBJECT(val, recent_cutoff, recent_cutoff);
 }
 
-rapidjson::Value GetOutputHistogram::Response::toJson(rapidjson::Document& doc) const
+void GetOutputHistogram::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, histogram, histogram);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, histogram, histogram);
 }
 
-void GetOutputHistogram::Response::fromJson(rapidjson::Value& val)
+void GetOutputHistogram::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, histogram, histogram);
 }
 
 
-rapidjson::Value GetOutputKeys::Request::toJson(rapidjson::Document& doc) const
+void GetOutputKeys::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, outputs, outputs);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, outputs, outputs);
 }
 
-void GetOutputKeys::Request::fromJson(rapidjson::Value& val)
+void GetOutputKeys::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, outputs, outputs);
 }
 
-rapidjson::Value GetOutputKeys::Response::toJson(rapidjson::Document& doc) const
+void GetOutputKeys::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, keys, keys);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, keys, keys);
 }
 
-void GetOutputKeys::Response::fromJson(rapidjson::Value& val)
+void GetOutputKeys::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, keys, keys);
 }
 
 
-rapidjson::Value GetRPCVersion::Request::toJson(rapidjson::Document& doc) const
-{
-  return Message::toJson(doc);
-}
+void GetRPCVersion::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+{}
 
-void GetRPCVersion::Request::fromJson(rapidjson::Value& val)
+void GetRPCVersion::Request::fromJson(const rapidjson::Value& val)
 {
 }
 
-rapidjson::Value GetRPCVersion::Response::toJson(rapidjson::Document& doc) const
+void GetRPCVersion::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, version, version);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, version, version);
 }
 
-void GetRPCVersion::Response::fromJson(rapidjson::Value& val)
+void GetRPCVersion::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, version, version);
 }
 
-rapidjson::Value GetFeeEstimate::Request::toJson(rapidjson::Document& doc) const
+void GetFeeEstimate::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, num_grace_blocks, num_grace_blocks);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, num_grace_blocks, num_grace_blocks);
 }
 
-void GetFeeEstimate::Request::fromJson(rapidjson::Value& val)
+void GetFeeEstimate::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, num_grace_blocks, num_grace_blocks);
 }
 
-rapidjson::Value GetFeeEstimate::Response::toJson(rapidjson::Document& doc) const
+void GetFeeEstimate::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, estimated_base_fee, estimated_base_fee);
-  INSERT_INTO_JSON_OBJECT(val, doc, fee_mask, fee_mask);
-  INSERT_INTO_JSON_OBJECT(val, doc, size_scale, size_scale);
-  INSERT_INTO_JSON_OBJECT(val, doc, hard_fork_version, hard_fork_version);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, estimated_base_fee, estimated_base_fee);
+  INSERT_INTO_JSON_OBJECT(dest, fee_mask, fee_mask);
+  INSERT_INTO_JSON_OBJECT(dest, size_scale, size_scale);
+  INSERT_INTO_JSON_OBJECT(dest, hard_fork_version, hard_fork_version);
 }
 
-void GetFeeEstimate::Response::fromJson(rapidjson::Value& val)
+void GetFeeEstimate::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, estimated_base_fee, estimated_base_fee);
   GET_FROM_JSON_OBJECT(val, fee_mask, fee_mask);
@@ -811,19 +581,15 @@ void GetFeeEstimate::Response::fromJson(rapidjson::Value& val)
   GET_FROM_JSON_OBJECT(val, hard_fork_version, hard_fork_version);
 }
 
-rapidjson::Value GetOutputDistribution::Request::toJson(rapidjson::Document& doc) const
+void GetOutputDistribution::Request::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, amounts, amounts);
-  INSERT_INTO_JSON_OBJECT(val, doc, from_height, from_height);
-  INSERT_INTO_JSON_OBJECT(val, doc, to_height, to_height);
-  INSERT_INTO_JSON_OBJECT(val, doc, cumulative, cumulative);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, amounts, amounts);
+  INSERT_INTO_JSON_OBJECT(dest, from_height, from_height);
+  INSERT_INTO_JSON_OBJECT(dest, to_height, to_height);
+  INSERT_INTO_JSON_OBJECT(dest, cumulative, cumulative);
 }
 
-void GetOutputDistribution::Request::fromJson(rapidjson::Value& val)
+void GetOutputDistribution::Request::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, amounts, amounts);
   GET_FROM_JSON_OBJECT(val, from_height, from_height);
@@ -831,17 +597,13 @@ void GetOutputDistribution::Request::fromJson(rapidjson::Value& val)
   GET_FROM_JSON_OBJECT(val, cumulative, cumulative);
 }
 
-rapidjson::Value GetOutputDistribution::Response::toJson(rapidjson::Document& doc) const
+void GetOutputDistribution::Response::doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  auto val = Message::toJson(doc);
-
-  INSERT_INTO_JSON_OBJECT(val, doc, status, status);
-  INSERT_INTO_JSON_OBJECT(val, doc, distributions, distributions);
-
-  return val;
+  INSERT_INTO_JSON_OBJECT(dest, status, status);
+  INSERT_INTO_JSON_OBJECT(dest, distributions, distributions);
 }
 
-void GetOutputDistribution::Response::fromJson(rapidjson::Value& val)
+void GetOutputDistribution::Response::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, status, status);
   GET_FROM_JSON_OBJECT(val, distributions, distributions);
diff --git a/src/rpc/daemon_messages.h b/src/rpc/daemon_messages.h
index c0d9aed0a..bb5059cdc 100644
--- a/src/rpc/daemon_messages.h
+++ b/src/rpc/daemon_messages.h
@@ -28,6 +28,8 @@
 
 #pragma once
 
+#include <rapidjson/stringbuffer.h>
+#include <rapidjson/writer.h>
 #include <unordered_map>
 #include <vector>
 
@@ -40,26 +42,25 @@
 #define BEGIN_RPC_MESSAGE_CLASS(classname) \
 class classname \
 { \
-  public: \
-    static const char* const name;
+  public:
 
 #define BEGIN_RPC_MESSAGE_REQUEST \
-    class Request : public Message \
+    class Request final : public Message \
     { \
       public: \
         Request() { } \
         ~Request() { } \
-        rapidjson::Value toJson(rapidjson::Document& doc) const; \
-        void fromJson(rapidjson::Value& val);
+        void doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const override final; \
+        void fromJson(const rapidjson::Value& val) override final;
 
 #define BEGIN_RPC_MESSAGE_RESPONSE \
-    class Response : public Message \
+    class Response final : public Message \
     { \
       public: \
         Response() { } \
         ~Response() { } \
-        rapidjson::Value toJson(rapidjson::Document& doc) const; \
-        void fromJson(rapidjson::Value& val);
+        void doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const override final; \
+        void fromJson(const rapidjson::Value& val) override final;
 
 #define END_RPC_MESSAGE_REQUEST };
 #define END_RPC_MESSAGE_RESPONSE };
diff --git a/src/rpc/message.cpp b/src/rpc/message.cpp
index 158b58005..a3df7fb56 100644
--- a/src/rpc/message.cpp
+++ b/src/rpc/message.cpp
@@ -27,12 +27,10 @@
 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "message.h"
+
 #include "daemon_rpc_version.h"
 #include "serialization/json_object.h"
 
-#include "rapidjson/writer.h"
-#include "rapidjson/stringbuffer.h"
-
 namespace cryptonote
 {
 
@@ -54,60 +52,23 @@ constexpr const char params_field[] = "params";
 constexpr const char result_field[] = "result";
 }
 
-rapidjson::Value Message::toJson(rapidjson::Document& doc) const
+void Message::toJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
 {
-  rapidjson::Value val(rapidjson::kObjectType);
-
-  auto& al = doc.GetAllocator();
-
-  val.AddMember("status", rapidjson::StringRef(status.c_str()), al);
-  val.AddMember("error_details", rapidjson::StringRef(error_details.c_str()), al);
-  INSERT_INTO_JSON_OBJECT(val, doc, rpc_version, DAEMON_RPC_VERSION_ZMQ);
-
-  return val;
+  dest.StartObject();
+  INSERT_INTO_JSON_OBJECT(dest, status, status);
+  INSERT_INTO_JSON_OBJECT(dest, error_details, error_details);
+  INSERT_INTO_JSON_OBJECT(dest, rpc_version, DAEMON_RPC_VERSION_ZMQ);
+  doToJson(dest);
+  dest.EndObject();
 }
 
-void Message::fromJson(rapidjson::Value& val)
+void Message::fromJson(const rapidjson::Value& val)
 {
   GET_FROM_JSON_OBJECT(val, status, status);
   GET_FROM_JSON_OBJECT(val, error_details, error_details);
   GET_FROM_JSON_OBJECT(val, rpc_version, rpc_version);
 }
 
-
-FullMessage::FullMessage(const std::string& request, Message* message)
-{
-  doc.SetObject();
-
-  doc.AddMember(method_field, rapidjson::StringRef(request.c_str()), doc.GetAllocator());
-  doc.AddMember(params_field, message->toJson(doc), doc.GetAllocator());
-
-  // required by JSON-RPC 2.0 spec
-  doc.AddMember("jsonrpc", rapidjson::Value("2.0"), doc.GetAllocator());
-}
-
-FullMessage::FullMessage(Message* message)
-{
-  doc.SetObject();
-
-  // required by JSON-RPC 2.0 spec
-  doc.AddMember("jsonrpc", "2.0", doc.GetAllocator());
-
-  if (message->status == Message::STATUS_OK)
-  {
-    doc.AddMember(result_field, message->toJson(doc), doc.GetAllocator());
-  }
-  else
-  {
-    cryptonote::rpc::error err;
-
-    err.error_str = message->status;
-    err.message = message->error_details;
-
-    INSERT_INTO_JSON_OBJECT(doc, doc, error, err);
-  }
-}
-
 FullMessage::FullMessage(const std::string& json_string, bool request)
 {
   doc.Parse(json_string.c_str());
@@ -132,30 +93,13 @@ FullMessage::FullMessage(const std::string& json_string, bool request)
   }
 }
 
-std::string FullMessage::getJson()
-{
-
-  if (!doc.HasMember(id_field))
-  {
-    doc.AddMember(id_field, rapidjson::Value("unused"), doc.GetAllocator());
-  }
-
-  rapidjson::StringBuffer buf;
-
-  rapidjson::Writer<rapidjson::StringBuffer> writer(buf);
-
-  doc.Accept(writer);
-
-  return std::string(buf.GetString(), buf.GetSize());
-}
-
 std::string FullMessage::getRequestType() const
 {
   OBJECT_HAS_MEMBER_OR_THROW(doc, method_field)
   return doc[method_field].GetString();
 }
 
-rapidjson::Value& FullMessage::getMessage()
+const rapidjson::Value& FullMessage::getMessage() const
 {
   if (doc.HasMember(params_field))
   {
@@ -174,30 +118,15 @@ rapidjson::Value& FullMessage::getMessage()
 
 rapidjson::Value FullMessage::getMessageCopy()
 {
-  rapidjson::Value& val = getMessage();
-
-  return rapidjson::Value(val, doc.GetAllocator());
+  return rapidjson::Value(getMessage(), doc.GetAllocator());
 }
 
-rapidjson::Value& FullMessage::getID()
+const rapidjson::Value& FullMessage::getID() const
 {
   OBJECT_HAS_MEMBER_OR_THROW(doc, id_field)
   return doc[id_field];
 }
 
-void FullMessage::setID(rapidjson::Value& id)
-{
-  auto itr = doc.FindMember(id_field);
-  if (itr != doc.MemberEnd())
-  {
-    itr->value = id;
-  }
-  else
-  {
-    doc.AddMember(id_field, id, doc.GetAllocator());
-  }
-}
-
 cryptonote::rpc::error FullMessage::getError()
 {
   cryptonote::rpc::error err;
@@ -211,82 +140,89 @@ cryptonote::rpc::error FullMessage::getError()
   return err;
 }
 
-FullMessage FullMessage::requestMessage(const std::string& request, Message* message)
+std::string FullMessage::getRequest(const std::string& request, const Message& message, const unsigned id)
 {
-  return FullMessage(request, message);
-}
+  rapidjson::StringBuffer buffer;
+  {
+    rapidjson::Writer<rapidjson::StringBuffer> dest{buffer};
 
-FullMessage FullMessage::requestMessage(const std::string& request, Message* message, rapidjson::Value& id)
-{
-  auto mes = requestMessage(request, message);
-  mes.setID(id);
-  return mes;
-}
+    dest.StartObject();
+    INSERT_INTO_JSON_OBJECT(dest, jsonrpc, (boost::string_ref{"2.0", 3}));
 
-FullMessage FullMessage::responseMessage(Message* message)
-{
-  return FullMessage(message);
-}
+    dest.Key(id_field);
+    json::toJsonValue(dest, id);
 
-FullMessage FullMessage::responseMessage(Message* message, rapidjson::Value& id)
-{
-  auto mes = responseMessage(message);
-  mes.setID(id);
-  return mes;
+    dest.Key(method_field);
+    json::toJsonValue(dest, request);
+
+    dest.Key(params_field);
+    message.toJson(dest);
+
+    dest.EndObject();
+
+    if (!dest.IsComplete())
+      throw std::logic_error{"Invalid JSON tree generated"};
+  }
+  return std::string{buffer.GetString(), buffer.GetSize()};
 }
 
-FullMessage* FullMessage::timeoutMessage()
+
+std::string FullMessage::getResponse(const Message& message, const rapidjson::Value& id)
 {
-  auto *full_message = new FullMessage();
+  rapidjson::StringBuffer buffer;
+  {
+    rapidjson::Writer<rapidjson::StringBuffer> dest{buffer};
 
-  auto& doc = full_message->doc;
-  auto& al = full_message->doc.GetAllocator();
+    dest.StartObject();
+    INSERT_INTO_JSON_OBJECT(dest, jsonrpc, (boost::string_ref{"2.0", 3}));
 
-  doc.SetObject();
+    dest.Key(id_field);
+    json::toJsonValue(dest, id);
 
-  // required by JSON-RPC 2.0 spec
-  doc.AddMember("jsonrpc", "2.0", al);
+    if (message.status == Message::STATUS_OK)
+    {
+      dest.Key(result_field);
+      message.toJson(dest);
+    }
+    else
+    {
+      cryptonote::rpc::error err;
 
-  cryptonote::rpc::error err;
+      err.error_str = message.status;
+      err.message = message.error_details;
 
-  err.error_str = "RPC request timed out.";
-  INSERT_INTO_JSON_OBJECT(doc, doc, err, err);
+      INSERT_INTO_JSON_OBJECT(dest, error, err);
+    }
+    dest.EndObject();
 
-  return full_message;
+    if (!dest.IsComplete())
+      throw std::logic_error{"Invalid JSON tree generated"};
+  }
+  return std::string{buffer.GetString(), buffer.GetSize()};
 }
 
 // convenience functions for bad input
 std::string BAD_REQUEST(const std::string& request)
 {
-  Message fail;
-  fail.status = Message::STATUS_BAD_REQUEST;
-  fail.error_details = std::string("\"") + request + "\" is not a valid request.";
-
-  FullMessage fail_response = FullMessage::responseMessage(&fail);
-
-  return fail_response.getJson();
+  rapidjson::Value invalid;
+  return BAD_REQUEST(request, invalid);
 }
 
-std::string BAD_REQUEST(const std::string& request, rapidjson::Value& id)
+std::string BAD_REQUEST(const std::string& request, const rapidjson::Value& id)
 {
   Message fail;
   fail.status = Message::STATUS_BAD_REQUEST;
   fail.error_details = std::string("\"") + request + "\" is not a valid request.";
-
-  FullMessage fail_response = FullMessage::responseMessage(&fail, id);
-
-  return fail_response.getJson();
+  return FullMessage::getResponse(fail, id);
 }
 
 std::string BAD_JSON(const std::string& error_details)
 {
+  rapidjson::Value invalid;
   Message fail;
   fail.status = Message::STATUS_BAD_JSON;
   fail.error_details = error_details;
-
-  FullMessage fail_response = FullMessage::responseMessage(&fail);
-
-  return fail_response.getJson();
+  return FullMessage::getResponse(fail, invalid);
 }
 
 
diff --git a/src/rpc/message.h b/src/rpc/message.h
index 2b7b61ab3..4cbc84fe4 100644
--- a/src/rpc/message.h
+++ b/src/rpc/message.h
@@ -28,27 +28,12 @@
 
 #pragma once
 
-#include "rapidjson/document.h"
-#include "rpc/message_data_structs.h"
+#include <rapidjson/document.h>
+#include <rapidjson/stringbuffer.h>
+#include <rapidjson/writer.h>
 #include <string>
 
-/* I normally hate using macros, but in this case it would be untenably
- * verbose to not use a macro.  This macro saves the trouble of explicitly
- * writing the below if block for every single RPC call.
- */
-#define REQ_RESP_TYPES_MACRO( runtime_str, type, reqjson, resp_message_ptr, handler) \
-  \
-  if (runtime_str == type::name) \
-  { \
-    type::Request reqvar; \
-    type::Response *respvar = new type::Response(); \
-    \
-    reqvar.fromJson(reqjson); \
-    \
-    handler(reqvar, *respvar); \
-    \
-    resp_message_ptr = respvar; \
-  }
+#include "rpc/message_data_structs.h"
 
 namespace cryptonote
 {
@@ -58,6 +43,9 @@ namespace rpc
 
   class Message
   {
+      virtual void doToJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const
+      {}
+
     public:
       static const char* STATUS_OK;
       static const char* STATUS_RETRY;
@@ -69,9 +57,9 @@ namespace rpc
 
       virtual ~Message() { }
 
-      virtual rapidjson::Value toJson(rapidjson::Document& doc) const;
+      void toJson(rapidjson::Writer<rapidjson::StringBuffer>& dest) const;
 
-      virtual void fromJson(rapidjson::Value& val);
+      virtual void fromJson(const rapidjson::Value& val);
 
       std::string status;
       std::string error_details;
@@ -87,27 +75,18 @@ namespace rpc
 
       FullMessage(const std::string& json_string, bool request=false);
 
-      std::string getJson();
-
       std::string getRequestType() const;
 
-      rapidjson::Value& getMessage();
+      const rapidjson::Value& getMessage() const;
 
       rapidjson::Value getMessageCopy();
 
-      rapidjson::Value& getID();
-
-      void setID(rapidjson::Value& id);
+      const rapidjson::Value& getID() const;
 
       cryptonote::rpc::error getError();
 
-      static FullMessage requestMessage(const std::string& request, Message* message);
-      static FullMessage requestMessage(const std::string& request, Message* message, rapidjson::Value& id);
-
-      static FullMessage responseMessage(Message* message);
-      static FullMessage responseMessage(Message* message, rapidjson::Value& id);
-
-      static FullMessage* timeoutMessage();
+      static std::string getRequest(const std::string& request, const Message& message, unsigned id);
+      static std::string getResponse(const Message& message, const rapidjson::Value& id);
     private:
 
       FullMessage() = default;
@@ -121,7 +100,7 @@ namespace rpc
 
   // convenience functions for bad input
   std::string BAD_REQUEST(const std::string& request);
-  std::string BAD_REQUEST(const std::string& request, rapidjson::Value& id);
+  std::string BAD_REQUEST(const std::string& request, const rapidjson::Value& id);
 
   std::string BAD_JSON(const std::string& error_details);