Switch from epee http server to boost::beast http server. Min boost 1.70 (#136)

There is roughly a 7.4% increase in performance in the switch to
boost::beast. Additionally, the REST endpoints `/daemon_status`,
`/get_unspent_outs`, and `/submit_raw_tx` do not block in ZMQ calls,
allowing for better response times regardless of `monerod` status.

The REST endpoints `/login and `/get_random_outs` still need updates
to prevent blocking (`/login` is conditional on DB state).

CMakeLists.txt

@@ -157,7 +157,7 @@ if(STATIC)
   set(Boost_USE_STATIC_LIBS ON)
   set(Boost_USE_STATIC_RUNTIME ON)
 endif()
-find_package(Boost 1.58 QUIET REQUIRED COMPONENTS chrono filesystem program_options regex serialization system thread)
+find_package(Boost 1.70 QUIET REQUIRED COMPONENTS chrono filesystem program_options regex serialization system thread)
 
 if (NOT (Boost_THREAD_LIBRARY STREQUAL monero_Boost_THREAD_LIBRARY_RELEASE))
   message(STATUS "Found Boost_THREAD_LIBRARY: ${Boost_THREAD_LIBRARY}")

README.md

@@ -62,7 +62,7 @@ library archives (`.a`).
 | ------------ | ------------- | -------- | -------------------- | ------------ | ------------------ | ------------------- | -------- | --------------- |
 | GCC          | 4.7.3         | NO       | `build-essential`    | `base-devel` | `base-devel`       | `gcc`               | NO       |                 |
 | CMake        | 3.1           | NO       | `cmake`              | `cmake`      | `cmake`            | `cmake`             | NO       |                 |
-| Boost        | 1.58          | NO       | `libboost-all-dev`   | `boost`      | `boost-devel`      | `boost-devel`       | NO       | C++ libraries   |
+| Boost        | 1.70          | NO       | `libboost-all-dev`   | `boost`      | `boost-devel`      | `boost-devel`       | NO       | C++ libraries   |
 | monero       | 0.15          | NO       |                      |              |                    |                     | NO       | Monero libraries|
 | OpenSSL      | basically any | NO       | `libssl-dev`         | `openssl`    | `libressl-devel`   | `openssl-devel`     | NO       | sha256 sum      |
 | libzmq       | 3.0.0         | NO       | `libzmq3-dev`        | `zeromq`     | `zeromq-devel`     | `zeromq-devel`      | NO       | ZeroMQ library  |

src/CMakeLists.txt

@@ -31,6 +31,7 @@ include_directories(.)
 add_subdirectory(lmdb)
 add_subdirectory(wire)
 add_subdirectory(db)
+add_subdirectory(net)
 add_subdirectory(rpc)
 add_subdirectory(util)
 
@@ -49,12 +50,14 @@ target_link_libraries(monero-lws-daemon-common
     ${MONERO_lmdb}
     monero-lws-common
     monero-lws-db
+    monero-lws-net
     monero-lws-rpc
     monero-lws-rpc-scanner
     monero-lws-wire-json
     monero-lws-util
     ${Boost_CHRONO_LIBRARY}
     ${Boost_PROGRAM_OPTIONS_LIBRARY}
+    ${Boost_SYSTEM_LIBRARY}
     ${Boost_THREAD_LIBRARY}
     ${Boost_THREAD_LIBS_INIT}
     ${EXTRA_LIBRARIES}

src/net/CMakeLists.txt

@@ -0,0 +1,33 @@
+# Copyright (c) 2024, The Monero Project
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are
+# permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this list of
+#    conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice, this list
+#    of conditions and the following disclaimer in the documentation and/or other
+#    materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors may be
+#    used to endorse or promote products derived from this software without specific
+#    prior written permission.
+#
+# 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.
+
+set(monero-lws-net_sources zmq_async.cpp)
+set(monero-lws-net_headers zmq_async.h)
+
+add_library(monero-lws-net ${monero-lws-net_sources} ${monero-lws-net_headers})
+target_link_libraries(monero-lws-net monero::libraries)

src/net/zmq_async.cpp

@@ -0,0 +1,103 @@
+// Copyright (c) 2024, The Monero Project
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// 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 "zmq_async.h"
+
+#include <stdexcept>
+
+namespace net { namespace zmq
+{
+  const boost::system::error_category& boost_error_category() noexcept
+  {
+    struct category final : boost::system::error_category
+    {
+      virtual const char* name() const noexcept override final
+      {
+        return "error::error_category()";
+      }
+
+      virtual std::string message(int value) const override final
+      {
+        char const* const msg = zmq_strerror(value);
+        if (msg)
+          return msg;
+        return "zmq_strerror failure";
+      }
+
+      virtual boost::system::error_condition default_error_condition(int value) const noexcept override final
+      {
+        // maps specific errors to generic `std::errc` cases.
+        switch (value)
+        {
+        case EFSM:
+        case ETERM:
+          break;
+        default:
+          /* zmq is using cerrno errors. C++ spec indicates that `std::errc`
+            values must be identical to the cerrno value. So just map every zmq
+            specific error to the generic errc equivalent. zmq extensions must
+            be in the switch or they map to a non-existent errc enum value. */
+          return boost::system::errc::errc_t(value);
+        }
+        return boost::system::error_condition{value, *this};
+      }
+    };
+    static const category instance{};
+    return instance;
+  }
+
+  boost::system::error_code make_error_code(std::error_code code)
+  {
+    if (std::addressof(code.category()) != std::addressof(error_category()))
+      throw std::logic_error{"Expected only ZMQ errors"};
+    return boost::system::error_code{code.value(), boost_error_category()};
+  }
+
+  void free_descriptor::operator()(adescriptor* ptr) noexcept
+  {
+    if (ptr)
+    {
+      ptr->release(); // release ASIO ownership, destroys all queued handlers
+      delete ptr;
+    }
+  }
+
+  expect<async_client> async_client::make(boost::asio::io_service& io, socket zsock)
+  {
+    MONERO_PRECOND(zsock != nullptr);
+
+    int fd = 0;
+    std::size_t length = sizeof(fd);
+    if (zmq_getsockopt(zsock.get(), ZMQ_FD, &fd, &length) != 0)
+      return net::zmq::get_error_code();
+
+    async_client out{std::move(zsock), nullptr, false};
+    out.asock.reset(new adescriptor{io, fd});
+    return out;
+  }
+}} // net // zmq
+

src/net/zmq_async.h

@@ -0,0 +1,165 @@
+// Copyright (c) 2024, The Monero Project
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// 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.
+
+#pragma once
+
+#include <boost/asio/compose.hpp>
+#include <boost/asio/io_service.hpp>
+#include <boost/asio/posix/stream_descriptor.hpp>
+#include <boost/system/error_code.hpp>
+#include <cstddef>
+#include <memory>
+#include <string>
+#include <zmq.h>
+#include "byte_slice.h"     // monero/contrib/epee/include
+#include "common/expect.h"  // monero/src
+#include "net/zmq.h"
+
+namespace net { namespace zmq
+{
+  //! \return Category for ZMQ errors.
+  const boost::system::error_category& boost_error_category() noexcept;
+
+  //! \return `code` iff the `::net::zmq` error category
+  boost::system::error_code make_error_code(std::error_code code);
+
+  using adescriptor = boost::asio::posix::stream_descriptor;
+
+  struct free_descriptor
+  {
+    void operator()(adescriptor* ptr) noexcept;
+  };
+
+  using asocket = std::unique_ptr<adescriptor, free_descriptor>;
+
+  struct async_client
+  {
+    async_client() = delete;
+    socket zsock;
+    asocket asock;
+    bool close;
+
+    static expect<async_client> make(boost::asio::io_service& io, socket zsock);
+  };
+
+  class read_msg_op
+  {
+    async_client* sock_;
+    std::string* msg_;
+
+  public:
+    read_msg_op(async_client& sock, std::string& msg)
+      : sock_(std::addressof(sock)), msg_(std::addressof(msg))
+    {}
+
+    template<typename F>
+    void operator()(F& self, const boost::system::error_code error = {}, std::size_t = 0)
+    {
+      if (error)
+        return self.complete(error, 0);
+      if (!sock_)
+        return;
+      if (sock_->close)
+        return self.complete(boost::asio::error::operation_aborted, 0);
+
+      assert(sock_->zsock && sock_->asock);
+      expect<std::string> msg = receive(sock_->zsock.get(), ZMQ_DONTWAIT);
+      if (!msg)
+      {
+        if (msg != make_error_code(EAGAIN))
+          return self.complete(make_error_code(msg.error()), 0);
+
+        // try again
+        sock_->asock->async_read_some(boost::asio::null_buffers(), std::move(self));
+        return;
+      }
+
+      *msg_ = std::move(*msg);
+      self.complete(error, msg_->size());
+    }
+  };
+
+  class write_msg_op
+  {
+    async_client* sock_;
+    epee::byte_slice msg_;
+
+  public:
+    write_msg_op(async_client& sock, epee::byte_slice msg)
+      : sock_(std::addressof(sock)), msg_(std::move(msg))
+    {}
+
+    template<typename F>
+    void operator()(F& self, const boost::system::error_code error = {}, std::size_t = 0)
+    {
+     if (error)
+        return self.complete(error, 0);
+      if (!sock_)
+        return;
+      if (sock_->close)
+        return self.complete(boost::asio::error::operation_aborted, 0);
+
+      assert(sock_->zsock && sock_->asock);
+
+      expect<void> status =
+        ::net::zmq::send(msg_.clone(), sock_->zsock.get(), ZMQ_DONTWAIT);
+      if (!status)
+      {
+        if (status != ::net::zmq::make_error_code(EAGAIN))
+          return self.complete(make_error_code(status.error()), 0);
+
+        // try again
+        sock_->asock->async_write_some(boost::asio::null_buffers(), std::move(self));
+        return;
+      }
+
+      self.complete(error, msg_.size());
+    }
+  };
+
+  //! Cannot have an `async_read` and `async_write` at same time (edge trigger)
+  template<typename F>
+  void async_read(async_client& sock, std::string& buffer, F&& f)
+  {
+    // async_compose is required for correct strand invocation, etc
+    boost::asio::async_compose<F, void(boost::system::error_code, std::size_t)>(
+      read_msg_op{sock, buffer}, f, *sock.asock
+    );
+  }
+
+  //! Cannot have an `async_write` and `async_read` at same time (edge trigger)
+  template<typename F>
+  void async_write(async_client& sock, epee::byte_slice msg, F&& f)
+  {
+    // async_compose is required for correct strand invocation, etc
+    boost::asio::async_compose<F, void(boost::system::error_code, std::size_t)>(
+      write_msg_op{sock, std::move(msg)}, f, *sock.asock
+    );
+  }
+
+}} // net // zmq
+

src/rest_server.h

@@ -28,6 +28,7 @@
 #pragma once
 
 #include <boost/asio/io_service.hpp>
+#include <boost/thread/thread.hpp>
 #include <cstddef>
 #include <list>
 #include <string>
@@ -43,9 +44,15 @@ namespace lws
   class rest_server
   {
     struct internal;
+    template<typename> struct connection;
+    template<typename> struct handler_loop;
+    template<typename> struct accept_loop;
     
-    boost::asio::io_service io_service_;
+    boost::asio::io_service io_service_; //!< Put first so its destroyed last
     std::list<internal> ports_;
+    std::vector<boost::thread> workers_;
+
+    void run_io();
     
   public:
     struct configuration

src/rpc/client.cpp

@@ -39,6 +39,7 @@
 #include "misc_log_ex.h"     // monero/contrib/epee/include
 #include "net/http_client.h" // monero/contrib/epee/include
 #include "net/zmq.h"         // monero/src
+#include "net/zmq_async.h"
 #include "scanner.h"
 #include "serialization/json_object.h" // monero/src
 #include "wire/msgpack.h"
@@ -140,7 +141,7 @@ namespace rpc
           break;
         const int err = zmq_errno();
         if (err != EINTR)
-          return net::zmq::make_error_code(err);
+          return ::net::zmq::make_error_code(err);
       }
       if (items[0].revents)
         return success();
@@ -186,7 +187,7 @@ namespace rpc
   {
     struct context
     {
-      explicit context(zcontext comm, socket signal_pub, socket external_pub, rcontext rmq, std::string daemon_addr, std::string sub_addr, std::chrono::minutes interval, bool untrusted_daemon)
+      explicit context(zcontext comm, net::zmq::socket signal_pub, net::zmq::socket external_pub, rcontext rmq, std::string daemon_addr, std::string sub_addr, std::chrono::minutes interval, bool untrusted_daemon)
         : comm(std::move(comm))
         , signal_pub(std::move(signal_pub))
         , external_pub(std::move(external_pub))
@@ -207,8 +208,8 @@ namespace rpc
       }
 
       zcontext comm;
-      socket signal_pub;
-      socket external_pub;
+      net::zmq::socket signal_pub;
+      net::zmq::socket external_pub;
       rcontext rmq;
       const std::string daemon_addr;
       const std::string sub_addr;
@@ -223,19 +224,15 @@ namespace rpc
     };
   } // detail
 
-  expect<void> client::get_response(cryptonote::rpc::Message& response, const std::chrono::seconds timeout, const source_location loc)
+  expect<void> parse_response(cryptonote::rpc::Message& parser, std::string msg, source_location loc)
   {
-    expect<std::string> message = get_message(timeout);
-    if (!message)
-      return message.error();
-
     try
     {
-      cryptonote::rpc::FullMessage fm{std::move(*message)};
+      cryptonote::rpc::FullMessage fm{std::move(msg)};
       const cryptonote::rpc::error json_error = fm.getError();
       if (!json_error.use)
       {
-        response.fromJson(fm.getMessage());
+        parser.fromJson(fm.getMessage());
         return success();
       }
 
@@ -249,6 +246,30 @@ namespace rpc
     return {lws::error::bad_daemon_response};
   }
 
+  expect<net::zmq::socket> client::make_daemon(const std::shared_ptr<detail::context>& ctx) noexcept
+  {
+    assert(ctx != nullptr);
+
+    net::zmq::socket daemon{zmq_socket(ctx->comm.get(), ZMQ_REQ)};
+
+    if (daemon.get() == nullptr)
+      return net::zmq::get_error_code();
+    MONERO_CHECK(do_set_option(daemon.get(), ZMQ_LINGER, daemon_zmq_linger));
+    if (ctx->untrusted_daemon)
+      MONERO_CHECK(do_set_option(daemon.get(), ZMQ_MAXMSGSIZE, max_msg_req));
+    MONERO_ZMQ_CHECK(zmq_connect(daemon.get(), ctx->daemon_addr.c_str()));
+
+    return daemon;
+  }
+
+  expect<void> client::get_response(cryptonote::rpc::Message& response, const std::chrono::seconds timeout, const source_location loc)
+  {
+    expect<std::string> message = get_message(timeout);
+    if (!message)
+      return message.error();
+    return parse_response(response, std::move(*message), loc);
+  }
+
   expect<std::string> client::get_message(std::chrono::seconds timeout)
   {
     MONERO_PRECOND(ctx != nullptr);
@@ -274,13 +295,10 @@ namespace rpc
 
     client out{std::move(ctx)};
 
-    out.daemon.reset(zmq_socket(out.ctx->comm.get(), ZMQ_REQ));
-    if (out.daemon.get() == nullptr)
-      return net::zmq::get_error_code();
-    MONERO_CHECK(do_set_option(out.daemon.get(), ZMQ_LINGER, daemon_zmq_linger));
-    if (out.ctx->untrusted_daemon)
-      MONERO_CHECK(do_set_option(out.daemon.get(), ZMQ_MAXMSGSIZE, max_msg_req));
-    MONERO_ZMQ_CHECK(zmq_connect(out.daemon.get(), out.ctx->daemon_addr.c_str()));
+    expect<net::zmq::socket> daemon = make_daemon(out.ctx);
+    if (!daemon)
+      return daemon.error();
+    out.daemon = std::move(*daemon);
 
     if (!out.ctx->sub_addr.empty())
     {
@@ -381,6 +399,16 @@ namespace rpc
     return {lws::error::bad_daemon_response};
   }
 
+  expect<net::zmq::async_client> client::make_async_client(boost::asio::io_service& io) const
+  {
+    MONERO_PRECOND(ctx != nullptr);
+
+    expect<net::zmq::socket> daemon = make_daemon(ctx);
+    if (!daemon)
+      return daemon.error();
+    return net::zmq::async_client::make(io, std::move(*daemon));
+  }
+
   expect<void> client::send(epee::byte_slice message, std::chrono::seconds timeout) noexcept
   {
     MONERO_PRECOND(ctx != nullptr);
@@ -399,7 +427,7 @@ namespace rpc
     return success();
   }
 
-  expect<void> client::publish(epee::byte_slice payload)
+  expect<void> client::publish(epee::byte_slice payload) const
   {
     MONERO_PRECOND(ctx != nullptr);
     assert(daemon != nullptr);
@@ -451,16 +479,16 @@ namespace rpc
     if (comm == nullptr)
       MONERO_THROW(net::zmq::get_error_code(), "zmq_init");
 
-    detail::socket pub{zmq_socket(comm.get(), ZMQ_PUB)};
+    net::zmq::socket pub{zmq_socket(comm.get(), ZMQ_PUB)};
     if (pub == nullptr)
       MONERO_THROW(net::zmq::get_error_code(), "zmq_socket");
     if (zmq_bind(pub.get(), signal_endpoint) < 0)
       MONERO_THROW(net::zmq::get_error_code(), "zmq_bind");
 
-    detail::socket external_pub = nullptr;
+    net::zmq::socket external_pub = nullptr;
     if (!pub_addr.empty())
     {
-      external_pub = detail::socket{zmq_socket(comm.get(), ZMQ_PUB)};
+      external_pub = net::zmq::socket{zmq_socket(comm.get(), ZMQ_PUB)};
       if (external_pub == nullptr)
         MONERO_THROW(net::zmq::get_error_code(), "zmq_socket");
       if (zmq_bind(external_pub.get(), pub_addr.c_str()) < 0)

src/rpc/client.h

@@ -26,6 +26,7 @@
 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #pragma once
 
+#include <boost/asio/io_service.hpp>
 #include <boost/optional/optional.hpp>
 #include <chrono>
 #include <memory>
@@ -36,27 +37,19 @@
 #include "byte_slice.h"    // monero/contrib/epee/include
 #include "db/fwd.h"
 #include "common/expect.h" // monero/src
+#include "net/zmq.h"       // monero/src
 #include "rpc/message.h"   // monero/src
 #include "rpc/daemon_pub.h"
 #include "rpc/rates.h"
 #include "util/source_location.h"
 
+namespace net { namespace zmq { struct async_client; }}
 namespace lws
 {
 namespace rpc
 {
   namespace detail
   {
-    struct close
-    {
-      void operator()(void* ptr) const noexcept
-      {
-        if (ptr)
-          zmq_close(ptr);
-      }
-    };
-    using socket = std::unique_ptr<void, close>;
-
     struct context;
   }
 
@@ -68,18 +61,23 @@ namespace rpc
     std::string routing;
   };
 
-  //! Abstraction for ZMQ RPC client. Only `get_rates()` thread-safe; use `clone()`.
+  expect<void> parse_response(cryptonote::rpc::Message& parser, std::string msg, source_location loc = {});
+
+  //! Abstraction for ZMQ RPC client. All `const` and `static` methods are thread-safe.
   class client
   {
     std::shared_ptr<detail::context> ctx;
-    detail::socket daemon;
-    detail::socket daemon_sub;
-    detail::socket signal_sub;
+    net::zmq::socket daemon;
+    net::zmq::socket daemon_sub;
+    net::zmq::socket signal_sub;
 
     explicit client(std::shared_ptr<detail::context> ctx) noexcept
       : ctx(std::move(ctx)), daemon(), daemon_sub(), signal_sub()
     {}
 
+    //! \return Connection to daemon REQ/REP.
+    static expect<net::zmq::socket> make_daemon(const std::shared_ptr<detail::context>& ctx) noexcept;
+
     //! Expect `response` as the next message payload unless error.
     expect<void> get_response(cryptonote::rpc::Message& response, std::chrono::seconds timeout, source_location loc);
 
@@ -140,6 +138,9 @@ namespace rpc
       return cryptonote::rpc::FullMessage::getRequest(name, message, 0);
     }
 
+    //! \return `async_client` to daemon. Thread safe.
+    expect<net::zmq::async_client> make_async_client(boost::asio::io_service& io) const;
+
     /*!
       Queue `message` for sending to daemon. If the queue is full, wait a
       maximum of `timeout` seconds or until `context::raise_abort_scan` or
@@ -148,11 +149,11 @@ namespace rpc
     expect<void> send(epee::byte_slice message, std::chrono::seconds timeout) noexcept;
 
     //! Publish `payload` to ZMQ external pub socket.
-    expect<void> publish(epee::byte_slice payload);
+    expect<void> publish(epee::byte_slice payload) const;
 
     //! Publish `data` after `topic` to ZMQ external pub socket.
     template<typename F, typename T>
-    expect<void> publish(const boost::string_ref topic, const T& data)
+    expect<void> publish(const boost::string_ref topic, const T& data) const
     {
       epee::byte_stream bytes{};
       bytes.write(topic.data(), topic.size());
@@ -174,15 +175,8 @@ namespace rpc
       return response;
     }
 
-    //! Retrieve new accounts to be scanned on this thread.
-    expect<std::vector<lws::account>> pull_accounts();
-
-    /*!
-      \note This is the one function that IS thread-safe. Multiple threads can
-        call this function with the same `this` argument.
-
-        \return Recent exchange rates.
-    */
+    /*! Never blocks for I/O - that is performed on another thread.
+      \return Recent exchange rates. */
     expect<rates> get_rates() const;
   };
 

src/rpc/light_wallet.cpp

@@ -34,6 +34,7 @@
 #include <stdexcept>
 #include <type_traits>
 
+#include "config.h"
 #include "db/string.h"
 #include "error.h"
 #include "time_helper.h"       // monero/contrib/epee/include
@@ -198,6 +199,14 @@ namespace lws
 
   namespace rpc
   {
+    daemon_status_response::daemon_status_response()
+      : outgoing_connections_count(0),
+        incoming_connections_count(0),
+        height(0),
+        network(lws::rpc::network_type(lws::config::network)),
+        state(daemon_state::unavailable)
+    {}
+
     namespace
     {
       constexpr const char* map_daemon_state[] = {"ok", "no_connections", "synchronizing", "unavailable"};

src/rpc/light_wallet.h

@@ -94,7 +94,9 @@ namespace rpc
 
   struct daemon_status_response
   {
-    daemon_status_response() = delete;
+    //! Defaults to current network in unavailable state
+    daemon_status_response();
+
     std::uint64_t outgoing_connections_count;
     std::uint64_t incoming_connections_count;
     std::uint64_t height;

src/rpc/webhook.h

@@ -138,7 +138,7 @@ namespace lws { namespace rpc
   }
 
   template<typename T>
-  void zmq_send(rpc::client& client, const epee::span<const T> events, const boost::string_ref json_topic, const boost::string_ref msgpack_topic)
+  void zmq_send(const rpc::client& client, const epee::span<const T> events, const boost::string_ref json_topic, const boost::string_ref msgpack_topic)
   {
     // Each `T` should have a unique count. This is desired.
     struct zmq_order
@@ -174,7 +174,7 @@ namespace lws { namespace rpc
 
   template<typename T>
   void send_webhook(
-    rpc::client& client,
+    const rpc::client& client,
     const epee::span<const T> events,
     const boost::string_ref json_topic,
     const boost::string_ref msgpack_topic,

src/util/CMakeLists.txt

@@ -27,7 +27,7 @@
 # THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 set(monero-lws-util_sources blocks.cpp gamma_picker.cpp random_outputs.cpp source_location.cpp transactions.cpp)
-set(monero-lws-util_headers blocks.h fwd.h gamma_picker.h http_server.h random_outputs.h source_location.h transactions.h)
+set(monero-lws-util_headers blocks.h fwd.h gamma_picker.h random_outputs.h source_location.h transactions.h)
 
 add_library(monero-lws-util ${monero-lws-util_sources} ${monero-lws-util_headers})
 target_link_libraries(monero-lws-util monero::libraries monero-lws-db)

src/util/http_server.h

@@ -1,124 +0,0 @@
-// Copyright (c) 2020, The Monero Project
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without modification, are
-// permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this list of
-//    conditions and the following disclaimer.
-//
-// 2. Redistributions in binary form must reproduce the above copyright notice, this list
-//    of conditions and the following disclaimer in the documentation and/or other
-//    materials provided with the distribution.
-//
-// 3. Neither the name of the copyright holder nor the names of its contributors may be
-//    used to endorse or promote products derived from this software without specific
-//    prior written permission.
-//
-// 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 <boost/bind/bind.hpp>
-#include <boost/thread.hpp>
-#include <boost/optional/optional.hpp>
-
-#include "misc_log_ex.h"
-#include "net/abstract_tcp_server2.h"      // monero/contrib/epee/include
-#include "net/http_protocol_handler.h"     // monero/contrib/epee/include
-#include "net/http_server_handlers_map2.h" // monero/contrib/epee/include
-
-#undef MONERO_DEFAULT_LOG_CATEGORY
-#define MONERO_DEFAULT_LOG_CATEGORY "net.http"
-
-
-namespace lws
-{
-  template<class t_child_class, class t_connection_context = epee::net_utils::connection_context_base>
-  class http_server_impl_base: public epee::net_utils::http::i_http_server_handler<t_connection_context>
-  {
-
-  public:
-    http_server_impl_base()
-        : m_net_server(epee::net_utils::e_connection_type_RPC)
-    {}
-
-    explicit http_server_impl_base(boost::asio::io_service& external_io_service)
-      : m_net_server(external_io_service, epee::net_utils::e_connection_type_RPC)
-    {}
-
-    bool init(const std::string& bind_port, const std::string& bind_ip,
-      std::vector<std::string> access_control_origins, epee::net_utils::ssl_options_t ssl_options)
-    {
-
-      //set self as callback handler
-      m_net_server.get_config_object().m_phandler = static_cast<t_child_class*>(this);
-  
-      //here set folder for hosting reqests
-      m_net_server.get_config_object().m_folder = "";
-
-      //set access control allow origins if configured
-      std::sort(access_control_origins.begin(), access_control_origins.end());
-      m_net_server.get_config_object().m_access_control_origins = std::move(access_control_origins);
-
-  
-      MGINFO("Binding on " << bind_ip << " (IPv4):" << bind_port);
-      bool res = m_net_server.init_server(bind_port, bind_ip, bind_port, std::string{}, false, true, std::move(ssl_options));
-      if(!res)
-      {
-        LOG_ERROR("Failed to bind server");
-        return false;
-      }
-      return true;
-    }
-
-    bool run(size_t threads_count, bool wait = true)
-    {
-      //go to loop
-      MINFO("Run net_service loop( " << threads_count << " threads)...");
-      if(!m_net_server.run_server(threads_count, wait))
-      {
-        LOG_ERROR("Failed to run net tcp server!");
-      }
-
-      if(wait)
-        MINFO("net_service loop stopped.");
-      return true;
-    }
-
-    bool deinit()
-    {
-      return m_net_server.deinit_server();
-    }
-
-    bool timed_wait_server_stop(uint64_t ms)
-    {
-      return m_net_server.timed_wait_server_stop(ms);
-    }
-
-    bool send_stop_signal()
-    {
-      m_net_server.send_stop_signal();
-      return true;
-    }
-
-    int get_binded_port()
-    {
-      return m_net_server.get_binded_port();
-    }
-
-    long get_connections_count() const
-    {
-      return m_net_server.get_connections_count();
-    }
-
-  protected: 
-    epee::net_utils::boosted_tcp_server<epee::net_utils::http::http_custom_handler<t_connection_context> > m_net_server;
-  };
-} // lws