From ec3b9533840712f41918c85c91cdfc05a1609ca1 Mon Sep 17 00:00:00 2001
From: Kurt Sassenrath <ksassenrath@roku.com>
Date: Tue, 5 Sep 2023 16:25:57 -0700
Subject: [PATCH] Various updates to initial server code.

Need to create user sessions and handle msgpack-encoded packets. The
plan is to use a branch of oh::msgpack with tl::expected.
---
 source/common/include/logging.h            |   1 +
 source/common/include/logging/formatters.h |  14 ++-
 source/common/include/logging/theme.h      |   6 ++
 source/server.cpp                          | 106 +++++++++++++++++++--
 4 files changed, 116 insertions(+), 11 deletions(-)

diff --git a/source/common/include/logging.h b/source/common/include/logging.h
index 66452f9..a2e3771 100644
--- a/source/common/include/logging.h
+++ b/source/common/include/logging.h
@@ -21,6 +21,7 @@
 
 #include <chrono>
 #include <memory>
+#include <span>
 #include <string_view>
 #include <vector>
 
diff --git a/source/common/include/logging/formatters.h b/source/common/include/logging/formatters.h
index a6dcf40..886530c 100644
--- a/source/common/include/logging/formatters.h
+++ b/source/common/include/logging/formatters.h
@@ -77,14 +77,22 @@ struct fmt::formatter<parselink::logging::enum_name_only<E>>
     }
 };
 
+template <>
+struct fmt::formatter<std::error_code> : fmt::formatter<std::string_view> {
+    template<typename FormatContext>
+    auto format(auto const& v, FormatContext& ctx) const {
+        return fmt::formatter<std::string_view>::format(v.message(), ctx);
+    }
+};
+
 // Support conversion of typical standard error codes into a human-readable
 // string.
 template <>
-struct fmt::formatter<std::errc> : fmt::formatter<std::string_view> {
+struct fmt::formatter<std::errc> : fmt::formatter<std::error_code> {
     template<typename FormatContext>
     auto format(std::errc const& v, FormatContext& ctx) const {
-        return fmt::formatter<std::string_view>::format(
-                std::make_error_code(v).message(), ctx);
+        return fmt::formatter<std::error_code>::format(
+                std::make_error_code(v), ctx);
     }
 };
 
diff --git a/source/common/include/logging/theme.h b/source/common/include/logging/theme.h
index 8084dd7..cfac7f6 100644
--- a/source/common/include/logging/theme.h
+++ b/source/common/include/logging/theme.h
@@ -84,12 +84,18 @@ template <typename E>
 requires std::is_enum_v<E>
 struct theme<E> : static_theme<fmt::color::gray> {};
 
+
+// Errors
+template <>
+struct theme<std::error_code> : static_theme<fmt::color::fire_brick> {};
+
 template <>
 struct theme<std::errc> : static_theme<fmt::color::fire_brick> {};
 
 template <>
 struct theme<error_str> : static_theme<fmt::color::fire_brick> {};
 
+
 template <>
 struct theme<enum_name_only<logging::level>> {
     constexpr static fmt::color colors[] = {
diff --git a/source/server.cpp b/source/server.cpp
index 1148cee..47c8f85 100644
--- a/source/server.cpp
+++ b/source/server.cpp
@@ -22,18 +22,75 @@
 #include <server.h>
 
 #include <boost/asio/io_context.hpp>
+#include <boost/asio/signal_set.hpp>
+#include <boost/asio/redirect_error.hpp>
+#include <boost/asio/write.hpp>
+
 #include <boost/asio/ip/address.hpp>
 #include <boost/asio/ip/tcp.hpp>
-#include <boost/asio/signal_set.hpp>
+
+#include <boost/asio/co_spawn.hpp>
+#include <boost/asio/deferred.hpp>
+#include <boost/asio/detached.hpp>
+#include <boost/asio/as_tuple.hpp>
+
+using namespace parselink;
 
 namespace net = boost::asio;
-using namespace parselink;
+using net::co_spawn;
+using net::awaitable;
+using net::use_awaitable;
+using net::deferred;
+using net::detached;
+
+//-----------------------------------------------------------------------------
+// TODO(ksassenrath): These are logging formatters for various boost/asio types.
+// Not all code is exposed to them, so they cannot be defined inside the
+// generic logging/formatters.h header. They should go somewhere else.
+//-----------------------------------------------------------------------------
+template <>
+struct parselink::logging::theme<boost::system::error_code>
+        : parselink::logging::static_theme<fmt::color::fire_brick> {};
+
+template <>
+struct fmt::formatter<boost::system::error_code>
+        : fmt::formatter<std::string_view> {
+    template<typename FormatContext>
+    constexpr auto format(auto const& v, FormatContext& ctx) const {
+        return fmt::formatter<std::string_view>::format(v.message(), ctx);
+    }
+};
+
+template <typename T>
+concept endpoint = requires(T const& t) {
+    {t.address()};
+    {t.port()};
+};
+
+template <endpoint T>
+struct parselink::logging::theme<T>
+        : parselink::logging::static_theme<fmt::color::coral> {};
+
+template <endpoint T>
+struct fmt::formatter<T>
+        : fmt::formatter<std::string_view> {
+    template<typename FormatContext>
+    constexpr auto format(auto const& v, FormatContext& ctx) const {
+        return fmt::format_to(ctx.out(), "{}:{}", v.address().to_string(),
+                v.port());
+    }
+};
+
+//-----------------------------------------------------------------------------
+// End formatters
+//-----------------------------------------------------------------------------
 
 namespace {
     logging::logger logger("server");
+    constexpr auto no_ex_coro = net::as_tuple(use_awaitable);
+    constexpr auto no_ex_defer = net::as_tuple(deferred);
 }
 
-
 class monolithic_server : public server {
 public:
     monolithic_server(std::string_view address, std::uint16_t user_port,
@@ -42,9 +99,14 @@ public:
     std::error_code run() noexcept override;
 
 private:
+
+    awaitable<void> echo(net::ip::tcp::socket socket);
+    awaitable<void> user_listen();
+
     net::io_context io_context_;
     net::ip::address addr_;
-    net::ip::tcp::acceptor user_acceptor_;
+    std::uint16_t user_port_;
+    std::uint16_t websocket_port_;
 };
 
 
@@ -52,10 +114,36 @@ monolithic_server::monolithic_server(std::string_view address,
         std::uint16_t user_port, std::uint16_t websocket_port)
         : io_context_{1}
         , addr_(net::ip::address::from_string(std::string{address}))
-        , user_acceptor_{io_context_, {addr_, user_port}} {
-    logger.debug("Creating monolithic_server with"
-            "\n\taddress {},\n\tuser_port {},\n\twebsocket_port {}",
-            address, user_port, websocket_port);
+        , user_port_{user_port}
+        , websocket_port_{websocket_port} {
+    logger.debug("Creating monolithic_server(address = {}, user_port = {}, "
+            "websocket_port = {})", address, user_port_, websocket_port_);
+}
+
+awaitable<void> monolithic_server::echo(net::ip::tcp::socket socket) {
+    std::array<std::byte, 4096> buffer;
+    while (true) {
+        auto [ec, n] = co_await socket.async_read_some(net::buffer(buffer), no_ex_coro);
+        if (ec) {
+            logger.error("Read from socket failed: {}", ec);
+            co_return;
+        }
+        auto [ec2, x] = co_await net::async_write(socket, net::buffer(buffer, n), no_ex_coro);
+        if (ec2) {
+            logger.error("Write to socket failed: {}", ec);
+            co_return;
+        }
+    }
+}
+
+awaitable<void> monolithic_server::user_listen() {
+    auto exec = co_await net::this_coro::executor;
+    net::ip::tcp::acceptor acceptor{exec, {addr_, user_port_}};
+    while (true) {
+        auto socket = co_await acceptor.async_accept(use_awaitable);
+        logger.debug("Accepted new connection from {}", socket.remote_endpoint());
+        co_spawn(exec, echo(std::move(socket)), detached);
+    }
 }
 
 std::error_code monolithic_server::run() noexcept {
@@ -67,6 +155,8 @@ std::error_code monolithic_server::run() noexcept {
         io_context_.stop();
     });
 
+    co_spawn(io_context_, user_listen(), detached);
+
     io_context_.run();
 
     return {};