Fix: Added more tests, fixed some bugs

.gitignore

@@ -33,4 +33,6 @@
 
 build
 CMakeUserPresets.json
-.vscode
+.vscode
+tests/functional/__pycache__
+Testing

configs/config.yaml

@@ -26,17 +26,7 @@ load_balancing:
 
 
   # Example config of least connections
-  algorithm: least_connections
-  endpoints:
-    - ip: "127.0.0.1"
-      port: 8081
-    - ip: "127.0.0.2"
-      port: 8082
-    - ip: "127.0.0.3"
-      port: 8083
-
-  # Example config of least response time
-  # algorithm: least_response_time
+  # algorithm: least_connections
   # endpoints:
   #   - ip: "127.0.0.1"
   #     port: 8081
@@ -45,6 +35,16 @@ load_balancing:
   #   - ip: "127.0.0.3"
   #     port: 8083
 
+  # Example config of least response time
+  algorithm: least_response_time
+  endpoints:
+    - ip: "127.0.0.1"
+      port: 8081
+    - ip: "127.0.0.2"
+      port: 8082
+    - ip: "127.0.0.3"
+      port: 8083
+
   # Example config of round robin
   # algorithm: round_robin
   # endpoints:

lbbuild.sh

@@ -9,7 +9,7 @@ function BuildApp() {
     conan install . --output-folder=build --build=missing --settings=build_type=$BUILD_TYPE
     cd build
     cmake .. -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DCMAKE_TOOLCHAIN_FILE=conan_toolchain.cmake
-    cmake --build . -j 4
+    cmake --build . -j 3
 }
 
 if ! command -v conan &> /dev/null

src/lb/formatters.hpp

@@ -10,4 +10,5 @@ namespace YAML {class Node;}
 template <> struct fmt::formatter<boost::stacktrace::stacktrace> : ostream_formatter{};
 template <> struct fmt::formatter<YAML::Node> : ostream_formatter{};
 template <> struct fmt::formatter<lb::tcp::Backend> : ostream_formatter{};
-template <> struct fmt::formatter<boost::beast::http::request<boost::beast::http::string_body>> : ostream_formatter{};
+template <> struct fmt::formatter<boost::beast::http::request<boost::beast::http::string_body>> : ostream_formatter{};
+template <> struct fmt::formatter<boost::beast::http::response<boost::beast::http::string_body>> : ostream_formatter{};

src/lb/tcp/connector.cpp

@@ -2,6 +2,8 @@
 #include <lb/tcp/connector.hpp>
 #include <lb/tcp/session.hpp>
 
+using SocketType = lb::tcp::HttpSession::SocketType;
+
 namespace lb::tcp {
 
 Connector::Connector(boost::asio::io_context& ctx, SelectorPtr selector)
@@ -10,38 +12,100 @@ Connector::Connector(boost::asio::io_context& ctx, SelectorPtr selector)
     , selector(selector)
 {}
 
-SessionPtr MakeSession(SelectorPtr& selector, boost::asio::ip::tcp::socket client_socket, boost::asio::ip::tcp::socket server_socket, Backend backend)
+
+class LeastConnectionsCallbacks : public StateNotifier
+{
+public:
+    LeastConnectionsCallbacks(Backend backend, SelectorPtr selector)
+        : StateNotifier()
+        , backend(std::move(backend))
+        , selector(std::dynamic_pointer_cast<LeastConnectionsSelector>(selector))
+    {}
+
+    void OnConnect() override
+    {
+        selector->IncreaseConnectionCount(backend);
+    }
+
+    void OnDisconnect() override
+    {
+        selector->DecreaseConnectionCount(backend);
+    }
+
+    using StateNotifier::StateNotifier;
+private:
+    Backend backend;
+    std::shared_ptr<LeastConnectionsSelector> selector;
+};
+
+
+class LeastResponseTimeCallbacks : public StateNotifier
 {
+public:
+    using TimeType = decltype(std::chrono::high_resolution_clock::now());
+public:
+    LeastResponseTimeCallbacks(Backend backend, SelectorPtr selector)
+        : StateNotifier()
+        , backend(std::move(backend))
+        , selector(std::dynamic_pointer_cast<LeastResponseTimeSelector>(selector))
+    {}
+
+    void OnRequestSent() override
+    {
+        response_begin = std::chrono::high_resolution_clock::now();
+    }
 
-    switch(selector->Type()) {
-        case SelectorType::LEAST_CONNECTIONS: {
-            std::shared_ptr<LeastConnectionsSelector>  lc_selector = std::dynamic_pointer_cast<LeastConnectionsSelector>(selector);
-            return std::make_shared<LeastConnectionsHttpSession>(std::move(client_socket), std::move(server_socket), lc_selector, backend);
-        } break;
-        case SelectorType::LEAST_RESPONSE_TIME: {
-            std::shared_ptr<LeastResponseTimeSelector> lrt_selector = std::dynamic_pointer_cast<LeastResponseTimeSelector>(selector);
-            return std::make_shared<LeastResponseTimeHttpSession>(std::move(client_socket), std::move(server_socket), lrt_selector, backend);
-        } break;
-        default: {
-            return std::make_shared<HttpSession>(std::move(client_socket), std::move(server_socket));
-        }
+    void OnResponseReceive() override
+    {
+        response_end = std::chrono::high_resolution_clock::now();
+        std::chrono::duration<long, std::nano> duration = response_end - response_begin;
+        selector->AddResponseTime(backend, duration.count());
+    }
+
+    using StateNotifier::StateNotifier;
+private:
+    Backend backend;
+    std::shared_ptr<LeastResponseTimeSelector> selector;
+    TimeType response_begin;
+    TimeType response_end;
+};
+
+SessionPtr MakeSession(SelectorPtr& selector,
+                       SocketType client_socket,
+                       SocketType server_socket,
+                       Backend backend)
+{
+    switch (selector->Type()) {
+    case SelectorType::LEAST_CONNECTIONS:
+    {
+        return std::make_shared<HttpSession>(std::move(client_socket), std::move(server_socket),
+                                             std::make_unique<LeastConnectionsCallbacks>(std::move(backend), selector));
+    } break;
+
+    case SelectorType::LEAST_RESPONSE_TIME:
+    {
+        return std::make_shared<HttpSession>(std::move(client_socket), std::move(server_socket),
+                                             std::make_unique<LeastResponseTimeCallbacks>(std::move(backend), selector));
+    } break;
+    default:
+        return std::make_shared<HttpSession>(std::move(client_socket), std::move(server_socket));
     }
 }
 
 
-void Connector::MakeAndRunSession(boost::asio::ip::tcp::socket client_socket)
+void Connector::MakeAndRunSession(SocketType client_socket)
 {
-    // TODO: selection of backend
     DEBUG("In connector");
     Backend backend = selector->SelectBackend(client_socket.remote_endpoint());
 
     if (backend.IsIpEndpoint()) {
         DEBUG("Is ip endpoint");
-        auto server_socket = std::make_shared<boost::asio::ip::tcp::socket>(client_socket.get_executor());
+        auto server_socket = std::make_shared<SocketType>(client_socket.get_executor());
 
         server_socket->async_connect(
             backend.AsEndpoint(),
-            [this, server_socket, client_socket=std::move(client_socket), backend=std::move(backend)] (const boost::system::error_code& error) mutable
+            [this, server_socket, client_socket=std::move(client_socket), backend=std::move(backend)]
+            (const boost::system::error_code& error) mutable
             {
                 if (error) {
                     ERROR("{}", error.message());
@@ -56,7 +120,7 @@ void Connector::MakeAndRunSession(boost::asio::ip::tcp::socket client_socket)
             });
     } else if (backend.IsUrl()) {
         DEBUG("Is url");
-        auto server_socket = std::make_shared<boost::asio::ip::tcp::socket>(client_socket.get_executor());
+        auto server_socket = std::make_shared<SocketType>(client_socket.get_executor());
 
         const auto& url = backend.AsUrl();
         DEBUG("URL: hostname: {}, port: {}", url.Hostname(), url.Port());

src/lb/tcp/connector.hpp

@@ -21,8 +21,7 @@ class Connector {
     Connector& operator=(Connector&&) = delete;
 
     void MakeAndRunSession(boost::asio::ip::tcp::socket client);
-private:
-    void HandleAsyncResolve(const boost::system::error_code& ec, ResolverResults results, boost::asio::ip::tcp::socket client_socket);
+
 private:
     boost::asio::io_context& ioc;
     boost::asio::ip::tcp::resolver resolver;

src/lb/tcp/selectors.cpp

@@ -152,6 +152,7 @@ SelectorPtr DetectSelector(const YAML::Node& node)
 // ============================ RoundRobinSelector ============================
 void RoundRobinSelector::Configure(const YAML::Node &balancing_node)
 {
+    INFO("Configuring RoundRobinSelector");
     if (!balancing_node["endpoints"].IsDefined()) {
         STACKTRACE("Round-robin endpoints node is missed");
     }
@@ -219,6 +220,7 @@ std::size_t ReadWeight(const YAML::Node& ep)
 
 void WeightedRoundRobinSelector::Configure(const YAML::Node &balancing_node)
 {
+    INFO("Configuring WeightedRoundRobinSelector");
     if (!balancing_node["endpoints"].IsDefined()) {
         STACKTRACE("Weighted-round-robin endpoints node is missed");
     }
@@ -314,6 +316,7 @@ void WeightedRoundRobinSelector::AdvanceCounter()
 
 void IpHashSelector::Configure(const YAML::Node& balancing_node)
 {
+    INFO("Configuring IpHashSelector");
     if (!balancing_node["endpoints"].IsDefined()) {
         STACKTRACE("Ip-hash endpoints node is missed");
     }
@@ -375,7 +378,10 @@ SelectorType IpHashSelector::Type() const
 
 BackendCHTraits::HashType BackendCHTraits::GetHash(const Backend& backend)
 {
-    return std::hash<std::string>{}(backend.ToString());
+
+    static std::hash<std::string> hash{};
+    std::size_t res = hash(backend.ToString());
+    return res;
 }
 
 std::vector<BackendCHTraits::HashType>
@@ -398,6 +404,7 @@ ConsistentHashSelector::ConsistentHashSelector(std::size_t spawn_replicas)
 
 void ConsistentHashSelector::Configure(const YAML::Node &balancing_node)
 {
+    INFO("Configuring ConsistentHashSelector");
     if (!balancing_node["endpoints"].IsDefined()) {
         STACKTRACE("Consistent hash endpoints node is missed");
     }
@@ -429,13 +436,15 @@ Backend ConsistentHashSelector::SelectBackend(const boost::asio::ip::tcp::endpoi
 {
     boost::mutex::scoped_lock lock(mutex_);
     Backend result = ring_.SelectNode(client);
+    DEBUG("Selected: {}", result);
     return result;
 }
 
 void ConsistentHashSelector::ExcludeBackend(const Backend& backend)
 {
     boost::mutex::scoped_lock lock(mutex_);
     ring_.EraseNode(backend);
+    DEBUG("Excluded: {}", backend);
     if (ring_.Empty()) {
         EXCEPTION("All backends are excluded!");
     }
@@ -449,6 +458,7 @@ SelectorType ConsistentHashSelector::Type() const
 // ============================ LeastConnectionsSelector ============================
 
 void LeastConnectionsSelector::Configure(const YAML::Node& config) {
+    INFO("Configuring LeastConnectionsSelector");
     if (!config["endpoints"].IsDefined()) {
         STACKTRACE("Least connections endpoints node is missed");
     }
@@ -546,6 +556,7 @@ void LeastConnectionsSelector::DecreaseConnectionCount(const Backend& backend)
 
 void LeastResponseTimeSelector::Configure(const YAML::Node& config)
 {
+    INFO("Configuring LeastResponseTimeSelector");
     if (!config["endpoints"].IsDefined()) {
         STACKTRACE("Least response time endpoints node is missed");
     }