Removes run_op from runner and renames runner to resp3_handshaker.

Author: mzimbres

include/boost/redis/detail/connection_base.hpp

@@ -8,39 +8,42 @@
 #define BOOST_REDIS_CONNECTION_BASE_HPP
 
 #include <boost/redis/adapter/adapt.hpp>
+#include <boost/redis/config.hpp>
+#include <boost/redis/detail/connector.hpp>
+#include <boost/redis/detail/health_checker.hpp>
 #include <boost/redis/detail/helper.hpp>
+#include <boost/redis/detail/resolver.hpp>
+#include <boost/redis/detail/resp3_handshaker.hpp>
 #include <boost/redis/error.hpp>
 #include <boost/redis/operation.hpp>
 #include <boost/redis/request.hpp>
 #include <boost/redis/resp3/type.hpp>
-#include <boost/redis/config.hpp>
-#include <boost/redis/detail/resolver.hpp>
-#include <boost/redis/detail/connector.hpp>
-#include <boost/redis/detail/health_checker.hpp>
-#include <boost/redis/detail/runner.hpp>
 #include <boost/redis/usage.hpp>
 
-#include <boost/system.hpp>
 #include <boost/asio/basic_stream_socket.hpp>
 #include <boost/asio/bind_executor.hpp>
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/cancel_after.hpp>
+#include <boost/asio/experimental/channel.hpp>
+#include <boost/asio/experimental/parallel_group.hpp>
 #include <boost/asio/ip/tcp.hpp>
+#include <boost/asio/prepend.hpp>
+#include <boost/asio/read_until.hpp>
+#include <boost/asio/ssl/stream.hpp>
 #include <boost/asio/steady_timer.hpp>
 #include <boost/asio/write.hpp>
 #include <boost/assert.hpp>
 #include <boost/core/ignore_unused.hpp>
-#include <boost/asio/ssl/stream.hpp>
-#include <boost/asio/read_until.hpp>
-#include <boost/asio/buffer.hpp>
-#include <boost/asio/experimental/channel.hpp>
+#include <boost/system.hpp>
 
 #include <algorithm>
 #include <array>
 #include <chrono>
 #include <deque>
+#include <functional>
 #include <memory>
 #include <string_view>
 #include <type_traits>
-#include <functional>
 
 namespace boost::redis::detail
 {
@@ -318,6 +321,135 @@ struct reader_op {
    }
 };
 
+template <class Conn, class Logger>
+class run_op {
+private:
+   Conn* conn_ = nullptr;
+   Logger logger_;
+   asio::coroutine coro_{};
+
+   using order_t = std::array<std::size_t, 5>;
+
+public:
+   run_op(Conn* conn, Logger l)
+   : conn_{conn}
+   , logger_{l}
+   {}
+
+   template <class Self>
+   void operator()( Self& self
+                  , order_t order = {}
+                  , system::error_code ec0 = {}
+                  , system::error_code ec1 = {}
+                  , system::error_code ec2 = {}
+                  , system::error_code ec3 = {}
+                  , system::error_code ec4 = {})
+   {
+      BOOST_ASIO_CORO_REENTER (coro_) for (;;)
+      {
+         BOOST_ASIO_CORO_YIELD
+         conn_->resv_.async_resolve(asio::prepend(std::move(self), order_t {}));
+
+         logger_.on_resolve(ec0, conn_->resv_.results());
+
+         if (ec0) {
+            self.complete(ec0);
+            return;
+         }
+
+         BOOST_ASIO_CORO_YIELD
+         conn_->ctor_.async_connect(
+            conn_->next_layer().next_layer(),
+            conn_->resv_.results(),
+            asio::prepend(std::move(self), order_t {}));
+
+         logger_.on_connect(ec0, conn_->ctor_.endpoint());
+
+         if (ec0) {
+            self.complete(ec0);
+            return;
+         }
+
+         if (conn_->use_ssl()) {
+            BOOST_ASIO_CORO_YIELD
+            conn_->next_layer().async_handshake(
+               asio::ssl::stream_base::client,
+               asio::prepend(
+                  asio::cancel_after(
+                     conn_->cfg_.ssl_handshake_timeout,
+                     std::move(self)
+                  ),
+                  order_t {}
+               )
+            );
+
+            logger_.on_ssl_handshake(ec0);
+
+            if (ec0) {
+               self.complete(ec0);
+               return;
+            }
+         }
+
+         conn_->reset();
+
+         // Note: Oder is important here because the writer might
+         // trigger an async_write before the async_hello thereby
+         // causing an authentication problem.
+         BOOST_ASIO_CORO_YIELD
+         asio::experimental::make_parallel_group(
+            [this](auto token) { return conn_->handshaker_.async_hello(*conn_, logger_, token); },
+            [this](auto token) { return conn_->health_checker_.async_ping(*conn_, logger_, token); },
+            [this](auto token) { return conn_->health_checker_.async_check_timeout(*conn_, logger_, token);},
+            [this](auto token) { return conn_->reader(logger_, token);},
+            [this](auto token) { return conn_->writer(logger_, token);}
+         ).async_wait(
+            asio::experimental::wait_for_one_error(),
+            std::move(self));
+
+         if (order[0] == 0 && !!ec0) {
+            self.complete(ec0);
+            return;
+         }
+
+         if (order[0] == 2 && ec2 == error::pong_timeout) {
+            self.complete(ec1);
+            return;
+         }
+
+         // The receive operation must be cancelled because channel
+         // subscription does not survive a reconnection but requires
+         // re-subscription.
+         conn_->cancel(operation::receive);
+
+         if (!conn_->will_reconnect()) {
+            conn_->cancel(operation::reconnection);
+            self.complete(ec3);
+            return;
+         }
+
+         // It is safe to use the writer timer here because we are not
+         // connected.
+         conn_->writer_timer_.expires_after(conn_->cfg_.reconnect_wait_interval);
+
+         BOOST_ASIO_CORO_YIELD
+         conn_->writer_timer_.async_wait(asio::prepend(std::move(self), order_t {}));
+         if (ec0) {
+            self.complete(ec0);
+            return;
+         }
+
+         if (!conn_->will_reconnect()) {
+            self.complete(asio::error::operation_aborted);
+            return;
+         }
+
+         conn_->reset_stream();
+      }
+   }
+};
+
+
 /** @brief Base class for high level Redis asynchronous connections.
  *  @ingroup high-level-api
  *
@@ -350,7 +482,6 @@ class connection_base {
    , receive_channel_{ex, 256}
    , resv_{ex}
    , health_checker_{ex}
-   , runner_{ex, {}}
    , dbuf_{read_buffer_, max_read_size}
    {
       set_receive_response(ignore);
@@ -464,9 +595,13 @@ class connection_base {
       resv_.set_config(cfg);
       ctor_.set_config(cfg);
       health_checker_.set_config(cfg);
-      runner_.set_config(cfg);
+      handshaker_.set_config(cfg);
       l.set_prefix(cfg.log_prefix);
-      return runner_.async_run(*this, l, std::move(token));
+
+      return asio::async_compose
+         < CompletionToken
+         , void(system::error_code)
+         >(run_op<this_type, Logger>{this, l}, token, writer_timer_);
    }
 
    template <class Response>
@@ -490,7 +625,7 @@ class connection_base {
    using receive_channel_type = asio::experimental::channel<executor_type, void(system::error_code, std::size_t)>;
    using resolver_type = resolver<Executor>;
    using health_checker_type = health_checker<Executor>;
-   using runner_type = runner<executor_type>;
+   using resp3_handshaker_type = resp3_handshaker<executor_type>;
    using adapter_type = std::function<void(std::size_t, resp3::basic_node<std::string_view> const&, system::error_code&)>;
    using receiver_adapter_type = std::function<void(resp3::basic_node<std::string_view> const&, system::error_code&)>;
    using exec_notifier_type = receive_channel_type;
@@ -669,7 +804,7 @@ class connection_base {
    template <class, class> friend struct reader_op;
    template <class, class> friend struct writer_op;
    template <class> friend struct exec_op;
-   template <class, class, class> friend struct runner_op;
+   template <class, class> friend class run_op;
 
    void cancel_push_requests()
    {
@@ -899,7 +1034,7 @@ class connection_base {
    resolver_type resv_;
    connector ctor_;
    health_checker_type health_checker_;
-   runner_type runner_;
+   resp3_handshaker_type handshaker_;
    receiver_adapter_type receive_adapter_;
 
    using dyn_buffer_type = asio::dynamic_string_buffer<char, std::char_traits<char>, std::allocator<char>>;

include/boost/redis/detail/health_checker.hpp

@@ -10,6 +10,7 @@
 #include <boost/redis/request.hpp>
 #include <boost/redis/response.hpp>
 #include <boost/redis/config.hpp>
+#include <boost/redis/operation.hpp>
 #include <boost/asio/steady_timer.hpp>
 #include <boost/asio/compose.hpp>
 #include <boost/asio/consign.hpp>

include/boost/redis/detail/resp3_handshaker.hpp

@@ -0,0 +1,116 @@
+/* Copyright (c) 2018-2024 Marcelo Zimbres Silva ([email protected])
+ *
+ * Distributed under the Boost Software License, Version 1.0. (See
+ * accompanying file LICENSE.txt)
+ */
+
+#ifndef BOOST_REDIS_RUNNER_HPP
+#define BOOST_REDIS_RUNNER_HPP
+
+#include <boost/redis/config.hpp>
+#include <boost/redis/request.hpp>
+#include <boost/redis/response.hpp>
+#include <boost/redis/error.hpp>
+#include <boost/redis/logger.hpp>
+#include <boost/redis/operation.hpp>
+#include <boost/asio/compose.hpp>
+#include <boost/asio/coroutine.hpp>
+//#include <boost/asio/ip/tcp.hpp>
+#include <string>
+#include <memory>
+#include <chrono>
+
+namespace boost::redis::detail
+{
+
+void push_hello(config const& cfg, request& req);
+
+// TODO: Can we avoid this whole function whose only purpose is to
+// check for an error in the hello response and complete with an error
+// so that the parallel group that starts it can exit?
+template <class Handshaker, class Connection, class Logger>
+struct hello_op {
+   Handshaker* handshaker_ = nullptr;
+   Connection* conn_ = nullptr;
+   Logger logger_;
+   asio::coroutine coro_{};
+
+   template <class Self>
+   void operator()(Self& self, system::error_code ec = {}, std::size_t = 0)
+   {
+      BOOST_ASIO_CORO_REENTER (coro_)
+      {
+         handshaker_->add_hello();
+
+         BOOST_ASIO_CORO_YIELD
+         conn_->async_exec(handshaker_->hello_req_, handshaker_->hello_resp_, std::move(self));
+         logger_.on_hello(ec, handshaker_->hello_resp_);
+
+         if (ec) {
+            conn_->cancel(operation::run);
+            self.complete(ec);
+            return;
+         }
+
+         if (handshaker_->has_error_in_response()) {
+            conn_->cancel(operation::run);
+            self.complete(error::resp3_hello);
+            return;
+         }
+
+         self.complete({});
+      }
+   }
+};
+
+template <class Executor>
+class resp3_handshaker {
+public:
+   void set_config(config const& cfg)
+      { cfg_ = cfg; }
+
+   template <class Connection, class Logger, class CompletionToken>
+   auto async_hello(Connection& conn, Logger l, CompletionToken token)
+   {
+      return asio::async_compose
+         < CompletionToken
+         , void(system::error_code)
+         >(hello_op<resp3_handshaker, Connection, Logger>{this, &conn, l}, token, conn);
+   }
+
+private:
+   template <class, class, class> friend struct hello_op;
+
+   void add_hello()
+   {
+      hello_req_.clear();
+      if (hello_resp_.has_value())
+         hello_resp_.value().clear();
+      push_hello(cfg_, hello_req_);
+   }
+
+   bool has_error_in_response() const noexcept
+   {
+      if (!hello_resp_.has_value())
+         return true;
+
+      auto f = [](auto const& e)
+      {
+         switch (e.data_type) {
+            case resp3::type::simple_error:
+            case resp3::type::blob_error: return true;
+            default: return false;
+         }
+      };
+
+      return std::any_of(std::cbegin(hello_resp_.value()), std::cend(hello_resp_.value()), f);
+   }
+
+   request hello_req_;
+   generic_response hello_resp_;
+   config cfg_;
+};
+
+} // boost::redis::detail
+
+#endif // BOOST_REDIS_RUNNER_HPP