first commit

ext/crow/ci_map.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <boost/algorithm/string/predicate.hpp>
+#include <boost/functional/hash.hpp>
+#include <unordered_map>
+
+namespace crow
+{
+    struct ci_hash
+    {
+        size_t operator()(const std::string& key) const
+        {
+            std::size_t seed = 0;
+            std::locale locale;
+
+            for(auto c : key)
+            {
+                boost::hash_combine(seed, std::toupper(c, locale));
+            }
+
+            return seed;
+        }
+    };
+
+    struct ci_key_eq
+    {
+        bool operator()(const std::string& l, const std::string& r) const
+        {
+            return boost::iequals(l, r);
+        }
+    };
+
+    using ci_map = std::unordered_multimap<std::string, std::string, ci_hash, ci_key_eq>;
+}

ext/crow/common.h

@@ -0,0 +1,126 @@
+#pragma once
+
+#include <vector>
+#include <string>
+#include <stdexcept>
+#include <iostream>
+#include "utility.h"
+
+namespace crow
+{
+    enum class HTTPMethod
+    {
+        DELETE,
+        GET,
+        HEAD,
+        POST,
+        PUT,
+        CONNECT,
+        OPTIONS,
+        TRACE,
+    };
+
+    inline std::string method_name(HTTPMethod method)
+    {
+        switch(method)
+        {
+            case HTTPMethod::DELETE:
+                return "DELETE";
+            case HTTPMethod::GET:
+                return "GET";
+            case HTTPMethod::HEAD:
+                return "HEAD";
+            case HTTPMethod::POST:
+                return "POST";
+            case HTTPMethod::PUT:
+                return "PUT";
+            case HTTPMethod::CONNECT:
+                return "CONNECT";
+            case HTTPMethod::OPTIONS:
+                return "OPTIONS";
+            case HTTPMethod::TRACE:
+                return "TRACE";
+        }
+        return "invalid";
+    }
+
+    enum class ParamType
+    {
+        INT,
+        UINT,
+        DOUBLE,
+        STRING,
+        PATH,
+
+        MAX
+    };
+
+    struct routing_params
+    {
+        std::vector<int64_t> int_params;
+        std::vector<uint64_t> uint_params;
+        std::vector<double> double_params;
+        std::vector<std::string> string_params;
+
+        void debug_print() const
+        {
+            std::cerr << "routing_params" << std::endl;
+            for(auto i:int_params)
+                std::cerr<<i <<", " ;
+            std::cerr<<std::endl;
+            for(auto i:uint_params)
+                std::cerr<<i <<", " ;
+            std::cerr<<std::endl;
+            for(auto i:double_params)
+                std::cerr<<i <<", " ;
+            std::cerr<<std::endl;
+            for(auto& i:string_params)
+                std::cerr<<i <<", " ;
+            std::cerr<<std::endl;
+        }
+
+        template <typename T>
+        T get(unsigned) const;
+
+    };
+
+    template<>
+    inline int64_t routing_params::get<int64_t>(unsigned index) const
+    {
+        return int_params[index];
+    }
+
+    template<>
+    inline uint64_t routing_params::get<uint64_t>(unsigned index) const
+    {
+        return uint_params[index];
+    }
+
+    template<>
+    inline double routing_params::get<double>(unsigned index) const
+    {
+        return double_params[index];
+    }
+
+    template<>
+    inline std::string routing_params::get<std::string>(unsigned index) const
+    {
+        return string_params[index];
+    }
+}
+
+#ifndef CROW_MSVC_WORKAROUND
+constexpr crow::HTTPMethod operator "" _method(const char* str, size_t len)
+{
+    return
+        crow::black_magic::is_equ_p(str, "GET", 3) ? crow::HTTPMethod::GET :
+        crow::black_magic::is_equ_p(str, "DELETE", 6) ? crow::HTTPMethod::DELETE :
+        crow::black_magic::is_equ_p(str, "HEAD", 4) ? crow::HTTPMethod::HEAD :
+        crow::black_magic::is_equ_p(str, "POST", 4) ? crow::HTTPMethod::POST :
+        crow::black_magic::is_equ_p(str, "PUT", 3) ? crow::HTTPMethod::PUT :
+        crow::black_magic::is_equ_p(str, "OPTIONS", 7) ? crow::HTTPMethod::OPTIONS :
+        crow::black_magic::is_equ_p(str, "CONNECT", 7) ? crow::HTTPMethod::CONNECT :
+        crow::black_magic::is_equ_p(str, "TRACE", 5) ? crow::HTTPMethod::TRACE :
+        throw std::runtime_error("invalid http method");
+};
+#endif

ext/crow/crow.h

@@ -0,0 +1,199 @@
+#pragma once
+
+#include <string>
+#include <functional>
+#include <memory>
+#include <future>
+#include <cstdint>
+#include <type_traits>
+#include <thread>
+
+#include "settings.h"
+#include "logging.h" 
+#include "utility.h"
+#include "routing.h"
+#include "middleware_context.h"
+#include "http_request.h"
+#include "http_server.h"
+
+
+#ifdef CROW_MSVC_WORKAROUND
+#define CROW_ROUTE(app, url) app.route_dynamic(url)
+#else
+#define CROW_ROUTE(app, url) app.route<crow::black_magic::get_parameter_tag(url)>(url)
+#endif
+
+namespace crow
+{
+#ifdef CROW_ENABLE_SSL
+    using ssl_context_t = boost::asio::ssl::context;
+#endif
+    template <typename ... Middlewares>
+    class Crow
+    {
+    public:
+        using self_t = Crow;
+        using server_t = Server<Crow, SocketAdaptor, Middlewares...>;
+#ifdef CROW_ENABLE_SSL
+        using ssl_server_t = Server<Crow, SSLAdaptor, Middlewares...>;
+#endif
+        Crow()
+        {
+        }
+
+        void handle(const request& req, response& res)
+        {
+            router_.handle(req, res);
+        }
+
+        DynamicRule& route_dynamic(std::string&& rule)
+        {
+            return router_.new_rule_dynamic(std::move(rule));
+        }
+
+        template <uint64_t Tag>
+        auto route(std::string&& rule)
+            -> typename std::result_of<decltype(&Router::new_rule_tagged<Tag>)(Router, std::string&&)>::type
+        {
+            return router_.new_rule_tagged<Tag>(std::move(rule));
+        }
+
+        self_t& port(std::uint16_t port)
+        {
+            port_ = port;
+            return *this;
+        }
+
+        self_t& multithreaded()
+        {
+            return concurrency(std::thread::hardware_concurrency());
+        }
+
+        self_t& concurrency(std::uint16_t concurrency)
+        {
+            if (concurrency < 1)
+                concurrency = 1;
+            concurrency_ = concurrency;
+            return *this;
+        }
+
+        void validate()
+        {
+            router_.validate();
+        }
+
+        void run()
+        {
+            validate();
+#ifdef CROW_ENABLE_SSL
+            if (use_ssl_)
+            {
+                ssl_server_t server(this, port_, &middlewares_, concurrency_, &ssl_context_);
+                server.run();
+            }
+            else
+#endif
+            {
+                server_t server(this, port_, &middlewares_, concurrency_, nullptr);
+                server.run();
+            }
+        }
+
+        void debug_print()
+        {
+            CROW_LOG_DEBUG << "Routing:";
+            router_.debug_print();
+        }
+
+#ifdef CROW_ENABLE_SSL
+        self_t& ssl_file(const std::string& crt_filename, const std::string& key_filename)
+        {
+            use_ssl_ = true;
+            ssl_context_.set_verify_mode(boost::asio::ssl::verify_peer);
+            ssl_context_.use_certificate_file(crt_filename, ssl_context_t::pem);
+            ssl_context_.use_private_key_file(key_filename, ssl_context_t::pem);
+            ssl_context_.set_options(
+                    boost::asio::ssl::context::default_workarounds
+                          | boost::asio::ssl::context::no_sslv2
+                          | boost::asio::ssl::context::no_sslv3
+                    );
+            return *this;
+        }
+
+        self_t& ssl_file(const std::string& pem_filename)
+        {
+            use_ssl_ = true;
+            ssl_context_.set_verify_mode(boost::asio::ssl::verify_peer);
+            ssl_context_.load_verify_file(pem_filename);
+            ssl_context_.set_options(
+                    boost::asio::ssl::context::default_workarounds
+                          | boost::asio::ssl::context::no_sslv2
+                          | boost::asio::ssl::context::no_sslv3
+                    );
+            return *this;
+        }
+
+        self_t& ssl(boost::asio::ssl::context&& ctx)
+        {
+            use_ssl_ = true;
+            ssl_context_ = std::move(ctx);
+            return *this;
+        }
+
+
+        bool use_ssl_{false};
+        ssl_context_t ssl_context_{boost::asio::ssl::context::sslv23};
+
+#else
+        template <typename T, typename ... Remain>
+        self_t& ssl_file(T&& t, Remain&&...)
+        {
+            // We can't call .ssl() member function unless CROW_ENABLE_SSL is defined.
+            static_assert(
+                    // make static_assert dependent to T; always false
+                    std::is_base_of<T, void>::value, 
+                    "Define CROW_ENABLE_SSL to enable ssl support.");
+            return *this;
+        }
+
+        template <typename T>
+        self_t& ssl(T&& ctx)
+        {
+            // We can't call .ssl() member function unless CROW_ENABLE_SSL is defined.
+            static_assert(
+                    // make static_assert dependent to T; always false
+                    std::is_base_of<T, void>::value, 
+                    "Define CROW_ENABLE_SSL to enable ssl support.");
+            return *this;
+        }
+#endif
+
+        // middleware
+        using context_t = detail::context<Middlewares...>;
+        template <typename T>
+        typename T::context& get_context(const request& req)
+        {
+            static_assert(black_magic::contains<T, Middlewares...>::value, "App doesn't have the specified middleware type.");
+            auto& ctx = *reinterpret_cast<context_t*>(req.middleware_context);
+            return ctx.template get<T>();
+        }
+
+        template <typename T>
+        T& get_middleware()
+        {
+            return utility::get_element_by_type<T, Middlewares...>(middlewares_);
+        }
+
+    private:
+        uint16_t port_ = 80;
+        uint16_t concurrency_ = 1;
+
+        Router router_;
+
+        std::tuple<Middlewares...> middlewares_;
+    };
+    template <typename ... Middlewares>
+    using App = Crow<Middlewares...>;
+    using SimpleApp = Crow<>;
+};
+

ext/crow/dumb_timer_queue.h

@@ -0,0 +1,81 @@
+#pragma once
+
+#include <boost/asio.hpp>
+#include <deque>
+#include <functional>
+#include <chrono>
+#include <thread>
+
+#include "logging.h"
+
+namespace crow
+{
+    namespace detail 
+    {
+        // fast timer queue for fixed tick value.
+        class dumb_timer_queue
+        {
+        public:
+            using key = std::pair<dumb_timer_queue*, int>;
+
+            void cancel(key& k)
+            {
+                auto self = k.first;
+                k.first = nullptr;
+                if (!self)
+                    return;
+
+                unsigned int index = (unsigned int)(k.second - self->step_);
+                if (index < self->dq_.size())
+                    self->dq_[index].second = nullptr;
+            }
+
+            key add(std::function<void()> f)
+            {
+                dq_.emplace_back(std::chrono::steady_clock::now(), std::move(f));
+                int ret = step_+dq_.size()-1;
+
+                CROW_LOG_DEBUG << "timer add inside: " << this << ' ' << ret ;
+                return {this, ret};
+            }
+
+            void process()
+            {
+                if (!io_service_)
+                    return;
+
+                auto now = std::chrono::steady_clock::now();
+                while(!dq_.empty())
+                {
+                    auto& x = dq_.front();
+                    if (now - x.first < std::chrono::seconds(tick))
+                        break;
+                    if (x.second)
+                    {
+                        CROW_LOG_DEBUG << "timer call: " << this << ' ' << step_;
+                        // we know that timer handlers are very simple currenty; call here
+                        x.second();
+                    }
+                    dq_.pop_front();
+                    step_++;
+                }
+            }
+
+            void set_io_service(boost::asio::io_service& io_service)
+            {
+                io_service_ = &io_service;
+            }
+
+            dumb_timer_queue() noexcept
+            {
+            }
+
+        private:
+
+            int tick{5};
+            boost::asio::io_service* io_service_{};
+            std::deque<std::pair<decltype(std::chrono::steady_clock::now()), std::function<void()>>> dq_;
+            int step_{};
+        };
+    }
+}

ext/crow/http_connection.h

@@ -0,0 +1,575 @@
+#pragma once
+#include <boost/asio.hpp>
+#include <boost/algorithm/string/predicate.hpp>
+#include <boost/lexical_cast.hpp>
+#include <boost/array.hpp>
+#include <atomic>
+#include <chrono>
+#include <vector>
+
+#include "http_parser_merged.h"
+
+#include "parser.h"
+#include "http_response.h"
+#include "logging.h"
+#include "settings.h"
+#include "dumb_timer_queue.h"
+#include "middleware_context.h"
+#include "socket_adaptors.h"
+
+namespace crow
+{
+    using namespace boost;
+    using tcp = asio::ip::tcp;
+
+    namespace detail
+    {
+        template <typename MW>
+        struct check_before_handle_arity_3_const
+        {
+            template <typename T,
+                void (T::*)(request&, response&, typename MW::context&) const = &T::before_handle
+            >
+            struct get
+            { };
+        };
+
+        template <typename MW>
+        struct check_before_handle_arity_3
+        {
+            template <typename T,
+                void (T::*)(request&, response&, typename MW::context&) = &T::before_handle
+            >
+            struct get
+            { };
+        };
+
+        template <typename MW>
+        struct check_after_handle_arity_3_const
+        {
+            template <typename T,
+                void (T::*)(request&, response&, typename MW::context&) const = &T::after_handle
+            >
+            struct get
+            { };
+        };
+
+        template <typename MW>
+        struct check_after_handle_arity_3
+        {
+            template <typename T,
+                void (T::*)(request&, response&, typename MW::context&) = &T::after_handle
+            >
+            struct get
+            { };
+        };
+
+        template <typename T>
+        struct is_before_handle_arity_3_impl
+        {
+            template <typename C>
+            static std::true_type f(typename check_before_handle_arity_3_const<T>::template get<C>*);
+
+            template <typename C>
+            static std::true_type f(typename check_before_handle_arity_3<T>::template get<C>*);
+
+            template <typename C>
+            static std::false_type f(...);
+
+        public:
+            static const bool value = decltype(f<T>(nullptr))::value;
+        };
+
+        template <typename T>
+        struct is_after_handle_arity_3_impl
+        {
+            template <typename C>
+            static std::true_type f(typename check_after_handle_arity_3_const<T>::template get<C>*);
+
+            template <typename C>
+            static std::true_type f(typename check_after_handle_arity_3<T>::template get<C>*);
+
+            template <typename C>
+            static std::false_type f(...);
+
+        public:
+            static const bool value = decltype(f<T>(nullptr))::value;
+        };
+
+        template <typename MW, typename Context, typename ParentContext>
+        typename std::enable_if<!is_before_handle_arity_3_impl<MW>::value>::type
+        before_handler_call(MW& mw, request& req, response& res, Context& ctx, ParentContext& parent_ctx)
+        {
+            mw.before_handle(req, res, ctx.template get<MW>(), ctx);
+        }
+
+        template <typename MW, typename Context, typename ParentContext>
+        typename std::enable_if<is_before_handle_arity_3_impl<MW>::value>::type
+        before_handler_call(MW& mw, request& req, response& res, Context& ctx, ParentContext& parent_ctx)
+        {
+            mw.before_handle(req, res, ctx.template get<MW>());
+        }
+
+        template <typename MW, typename Context, typename ParentContext>
+        typename std::enable_if<!is_after_handle_arity_3_impl<MW>::value>::type
+        after_handler_call(MW& mw, request& req, response& res, Context& ctx, ParentContext& parent_ctx)
+        {
+            mw.after_handle(req, res, ctx.template get<MW>(), ctx);
+        }
+
+        template <typename MW, typename Context, typename ParentContext>
+        typename std::enable_if<is_after_handle_arity_3_impl<MW>::value>::type
+        after_handler_call(MW& mw, request& req, response& res, Context& ctx, ParentContext& parent_ctx)
+        {
+            mw.after_handle(req, res, ctx.template get<MW>());
+        }
+
+        template <int N, typename Context, typename Container, typename CurrentMW, typename ... Middlewares>
+        bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx)
+        {
+            using parent_context_t = typename Context::template partial<N-1>;
+            before_handler_call<CurrentMW, Context, parent_context_t>(std::get<N>(middlewares), req, res, ctx, static_cast<parent_context_t&>(ctx));
+
+            if (res.is_completed())
+            {
+                after_handler_call<CurrentMW, Context, parent_context_t>(std::get<N>(middlewares), req, res, ctx, static_cast<parent_context_t&>(ctx));
+                return true;
+            }
+
+            if (middleware_call_helper<N+1, Context, Container, Middlewares...>(middlewares, req, res, ctx))
+            {
+                after_handler_call<CurrentMW, Context, parent_context_t>(std::get<N>(middlewares), req, res, ctx, static_cast<parent_context_t&>(ctx));
+                return true;
+            }
+
+            return false;
+        }
+
+        template <int N, typename Context, typename Container>
+        bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx)
+        {
+            return false;
+        }
+
+        template <int N, typename Context, typename Container>
+        typename std::enable_if<(N<0)>::type 
+        after_handlers_call_helper(Container& middlewares, Context& context, request& req, response& res)
+        {
+        }
+
+        template <int N, typename Context, typename Container>
+        typename std::enable_if<(N==0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res)
+        {
+            using parent_context_t = typename Context::template partial<N-1>;
+            using CurrentMW = typename std::tuple_element<N, typename std::remove_reference<Container>::type>::type;
+            after_handler_call<CurrentMW, Context, parent_context_t>(std::get<N>(middlewares), req, res, ctx, static_cast<parent_context_t&>(ctx));
+        }
+
+        template <int N, typename Context, typename Container>
+        typename std::enable_if<(N>0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res)
+        {
+            using parent_context_t = typename Context::template partial<N-1>;
+            using CurrentMW = typename std::tuple_element<N, typename std::remove_reference<Container>::type>::type;
+            after_handler_call<CurrentMW, Context, parent_context_t>(std::get<N>(middlewares), req, res, ctx, static_cast<parent_context_t&>(ctx));
+            after_handlers_call_helper<N-1, Context, Container>(middlewares, ctx, req, res);
+        }
+    }
+
+#ifdef CROW_ENABLE_DEBUG
+    static int connectionCount;
+#endif
+    template <typename Adaptor, typename Handler, typename ... Middlewares>
+    class Connection
+    {
+    public:
+        Connection(
+            boost::asio::io_service& io_service, 
+            Handler* handler, 
+            const std::string& server_name,
+            std::tuple<Middlewares...>* middlewares,
+            std::function<std::string()>& get_cached_date_str_f,
+            detail::dumb_timer_queue& timer_queue,
+            typename Adaptor::context* adaptor_ctx_
+            ) 
+            : adaptor_(io_service, adaptor_ctx_), 
+            handler_(handler), 
+            parser_(this), 
+            server_name_(server_name),
+            middlewares_(middlewares),
+            get_cached_date_str(get_cached_date_str_f),
+            timer_queue(timer_queue)
+        {
+#ifdef CROW_ENABLE_DEBUG
+            connectionCount ++;
+            CROW_LOG_DEBUG << "Connection open, total " << connectionCount << ", " << this;
+#endif
+        }
+        
+        ~Connection()
+        {
+            res.complete_request_handler_ = nullptr;
+            cancel_deadline_timer();
+#ifdef CROW_ENABLE_DEBUG
+            connectionCount --;
+            CROW_LOG_DEBUG << "Connection closed, total " << connectionCount << ", " << this;
+#endif
+        }
+
+        decltype(std::declval<Adaptor>().raw_socket())& socket()
+        {
+            return adaptor_.raw_socket();
+        }
+
+        void start()
+        {
+            adaptor_.start([this](const boost::system::error_code& ec) {
+                if (!ec)
+                {
+                    start_deadline();
+
+                    do_read();
+                }
+                else
+                {
+                    check_destroy();
+                }
+            });
+        }
+
+        void handle_header()
+        {
+            // HTTP 1.1 Expect: 100-continue
+            if (parser_.check_version(1, 1) && parser_.headers.count("expect") && get_header_value(parser_.headers, "expect") == "100-continue")
+            {
+                buffers_.clear();
+                static std::string expect_100_continue = "HTTP/1.1 100 Continue\r\n\r\n";
+                buffers_.emplace_back(expect_100_continue.data(), expect_100_continue.size());
+                do_write();
+            }
+        }
+
+        void handle()
+        {
+            cancel_deadline_timer();
+            bool is_invalid_request = false;
+            add_keep_alive_ = false;
+
+            req_ = std::move(parser_.to_request());
+            request& req = req_;
+            if (parser_.check_version(1, 0))
+            {
+                // HTTP/1.0
+                if (req.headers.count("connection"))
+                {
+                    if (boost::iequals(req.get_header_value("connection"),"Keep-Alive"))
+                        add_keep_alive_ = true;
+                }
+                else
+                    close_connection_ = true;
+            }
+            else if (parser_.check_version(1, 1))
+            {
+                // HTTP/1.1
+                if (req.headers.count("connection"))
+                {
+                    if (req.get_header_value("connection") == "close")
+                        close_connection_ = true;
+                    else if (boost::iequals(req.get_header_value("connection"),"Keep-Alive"))
+                        add_keep_alive_ = true;
+                }
+                if (!req.headers.count("host"))
+                {
+                    is_invalid_request = true;
+                    res = response(400);
+                }
+            }
+
+            CROW_LOG_INFO << "Request: " << boost::lexical_cast<std::string>(adaptor_.remote_endpoint()) << " " << this << " HTTP/" << parser_.http_major << "." << parser_.http_minor << ' '
+             << method_name(req.method) << " " << req.url;
+
+
+            need_to_call_after_handlers_ = false;
+            if (!is_invalid_request)
+            {
+                res.complete_request_handler_ = []{};
+                res.is_alive_helper_ = [this]()->bool{ return adaptor_.is_open(); };
+
+                ctx_ = detail::context<Middlewares...>();
+                req.middleware_context = (void*)&ctx_;
+                detail::middleware_call_helper<0, decltype(ctx_), decltype(*middlewares_), Middlewares...>(*middlewares_, req, res, ctx_);
+
+                if (!res.completed_)
+                {
+                    res.complete_request_handler_ = [this]{ this->complete_request(); };
+                    need_to_call_after_handlers_ = true;
+                    handler_->handle(req, res);
+                    if (add_keep_alive_)
+                        res.set_header("connection", "Keep-Alive");
+                }
+                else
+                {
+                    complete_request();
+                }
+            }
+            else
+            {
+                complete_request();
+            }
+        }
+
+        void complete_request()
+        {
+            CROW_LOG_INFO << "Response: " << this << ' ' << req_.raw_url << ' ' << res.code << ' ' << close_connection_;
+
+            if (need_to_call_after_handlers_)
+            {
+                need_to_call_after_handlers_ = false;
+
+                // call all after_handler of middlewares
+                detail::after_handlers_call_helper<
+                    ((int)sizeof...(Middlewares)-1),
+                    decltype(ctx_),
+                    decltype(*middlewares_)> 
+                (*middlewares_, ctx_, req_, res);
+            }
+
+            //auto self = this->shared_from_this();
+            res.complete_request_handler_ = nullptr;
+            
+            if (!adaptor_.is_open())
+            {
+                //CROW_LOG_DEBUG << this << " delete (socket is closed) " << is_reading << ' ' << is_writing;
+                //delete this;
+                return;
+            }
+
+            static std::unordered_map<int, std::string> statusCodes = {
+                {200, "HTTP/1.1 200 OK\r\n"},
+                {201, "HTTP/1.1 201 Created\r\n"},
+                {202, "HTTP/1.1 202 Accepted\r\n"},
+                {204, "HTTP/1.1 204 No Content\r\n"},
+
+                {300, "HTTP/1.1 300 Multiple Choices\r\n"},
+                {301, "HTTP/1.1 301 Moved Permanently\r\n"},
+                {302, "HTTP/1.1 302 Moved Temporarily\r\n"},
+                {304, "HTTP/1.1 304 Not Modified\r\n"},
+
+                {400, "HTTP/1.1 400 Bad Request\r\n"},
+                {401, "HTTP/1.1 401 Unauthorized\r\n"},
+                {403, "HTTP/1.1 403 Forbidden\r\n"},
+                {404, "HTTP/1.1 404 Not Found\r\n"},
+
+                {500, "HTTP/1.1 500 Internal Server Error\r\n"},
+                {501, "HTTP/1.1 501 Not Implemented\r\n"},
+                {502, "HTTP/1.1 502 Bad Gateway\r\n"},
+                {503, "HTTP/1.1 503 Service Unavailable\r\n"},
+            };
+
+            static std::string seperator = ": ";
+            static std::string crlf = "\r\n";
+
+            buffers_.clear();
+            buffers_.reserve(4*(res.headers.size()+5)+3);
+
+            if (res.body.empty() && res.json_value.t() == json::type::Object)
+            {
+                res.body = json::dump(res.json_value);
+            }
+
+            if (!statusCodes.count(res.code))
+                res.code = 500;
+            {
+                auto& status = statusCodes.find(res.code)->second;
+                buffers_.emplace_back(status.data(), status.size());
+            }
+
+            if (res.code >= 400 && res.body.empty())
+                res.body = statusCodes[res.code].substr(9);
+
+            for(auto& kv : res.headers)
+            {
+                buffers_.emplace_back(kv.first.data(), kv.first.size());
+                buffers_.emplace_back(seperator.data(), seperator.size());
+                buffers_.emplace_back(kv.second.data(), kv.second.size());
+                buffers_.emplace_back(crlf.data(), crlf.size());
+
+            }
+
+            if (!res.headers.count("content-length"))
+            {
+                content_length_ = std::to_string(res.body.size());
+                static std::string content_length_tag = "Content-Length: ";
+                buffers_.emplace_back(content_length_tag.data(), content_length_tag.size());
+                buffers_.emplace_back(content_length_.data(), content_length_.size());
+                buffers_.emplace_back(crlf.data(), crlf.size());
+            }
+            if (!res.headers.count("server"))
+            {
+                static std::string server_tag = "Server: ";
+                buffers_.emplace_back(server_tag.data(), server_tag.size());
+                buffers_.emplace_back(server_name_.data(), server_name_.size());
+                buffers_.emplace_back(crlf.data(), crlf.size());
+            }
+            if (!res.headers.count("date"))
+            {
+                static std::string date_tag = "Date: ";
+                date_str_ = get_cached_date_str();
+                buffers_.emplace_back(date_tag.data(), date_tag.size());
+                buffers_.emplace_back(date_str_.data(), date_str_.size());
+                buffers_.emplace_back(crlf.data(), crlf.size());
+            }
+            if (add_keep_alive_)
+            {
+                static std::string keep_alive_tag = "Connection: Keep-Alive";
+                buffers_.emplace_back(keep_alive_tag.data(), keep_alive_tag.size());
+                buffers_.emplace_back(crlf.data(), crlf.size());
+            }
+
+            buffers_.emplace_back(crlf.data(), crlf.size());
+            res_body_copy_.swap(res.body);
+            buffers_.emplace_back(res_body_copy_.data(), res_body_copy_.size());
+
+            do_write();
+
+            if (need_to_start_read_after_complete_)
+            {
+                need_to_start_read_after_complete_ = false;
+                start_deadline();
+                do_read();
+            }
+        }
+
+    private:
+        void do_read()
+        {
+            //auto self = this->shared_from_this();
+            is_reading = true;
+            adaptor_.socket().async_read_some(boost::asio::buffer(buffer_), 
+                [this](const boost::system::error_code& ec, std::size_t bytes_transferred)
+                {
+                    bool error_while_reading = true;
+                    if (!ec)
+                    {
+                        bool ret = parser_.feed(buffer_.data(), bytes_transferred);
+                        if (ret && adaptor_.is_open() && !close_connection_)
+                        {
+                            error_while_reading = false;
+                        }
+                    }
+
+                    if (error_while_reading)
+                    {
+                        cancel_deadline_timer();
+                        parser_.done();
+                        adaptor_.close();
+                        is_reading = false;
+                        CROW_LOG_DEBUG << this << " from read(1)";
+                        check_destroy();
+                    }
+                    else if (!need_to_call_after_handlers_)
+                    {
+                        start_deadline();
+                        do_read();
+                    }
+                    else
+                    {
+                        // res will be completed later by user
+                        need_to_start_read_after_complete_ = true;
+                    }
+                });
+        }
+
+        void do_write()
+        {
+            //auto self = this->shared_from_this();
+            is_writing = true;
+            boost::asio::async_write(adaptor_.socket(), buffers_, 
+                [&](const boost::system::error_code& ec, std::size_t bytes_transferred)
+                {
+                    is_writing = false;
+                    res.clear();
+                    res_body_copy_.clear();
+                    if (!ec)
+                    {
+                        if (close_connection_)
+                        {
+                            adaptor_.close();
+                            CROW_LOG_DEBUG << this << " from write(1)";
+                            check_destroy();
+                        }
+                    }
+                    else
+                    {
+                        CROW_LOG_DEBUG << this << " from write(2)";
+                        check_destroy();
+                    }
+                });
+        }
+
+        void check_destroy()
+        {
+            CROW_LOG_DEBUG << this << " is_reading " << is_reading << " is_writing " << is_writing;
+            if (!is_reading && !is_writing)
+            {
+                CROW_LOG_DEBUG << this << " delete (idle) ";
+                delete this;
+            }
+        }
+
+        void cancel_deadline_timer()
+        {
+            CROW_LOG_DEBUG << this << " timer cancelled: " << timer_cancel_key_.first << ' ' << timer_cancel_key_.second;
+            timer_queue.cancel(timer_cancel_key_);
+        }
+
+        void start_deadline(int timeout = 5)
+        {
+            cancel_deadline_timer();
+            
+            timer_cancel_key_ = timer_queue.add([this]
+            {
+                if (!adaptor_.is_open())
+                {
+                    return;
+                }
+                adaptor_.close();
+            });
+            CROW_LOG_DEBUG << this << " timer added: " << timer_cancel_key_.first << ' ' << timer_cancel_key_.second;
+        }
+
+    private:
+        Adaptor adaptor_;
+        Handler* handler_;
+
+        boost::array<char, 4096> buffer_;
+
+        HTTPParser<Connection> parser_;
+        request req_;
+        response res;
+
+        bool close_connection_ = false;
+
+        const std::string& server_name_;
+        std::vector<boost::asio::const_buffer> buffers_;
+
+        std::string content_length_;
+        std::string date_str_;
+        std::string res_body_copy_;
+
+        //boost::asio::deadline_timer deadline_;
+        detail::dumb_timer_queue::key timer_cancel_key_;
+
+        bool is_reading{};
+        bool is_writing{};
+        bool need_to_call_after_handlers_{};
+        bool need_to_start_read_after_complete_{};
+        bool add_keep_alive_{};
+
+        std::tuple<Middlewares...>* middlewares_;
+        detail::context<Middlewares...> ctx_;
+
+        std::function<std::string()>& get_cached_date_str;
+        detail::dumb_timer_queue& timer_queue;
+    };
+
+}

ext/crow/http_request.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include "common.h"
+#include "ci_map.h"
+#include "query_string.h"
+
+namespace crow
+{
+    template <typename T>
+    inline const std::string& get_header_value(const T& headers, const std::string& key)
+    {
+        if (headers.count(key))
+        {
+            return headers.find(key)->second;
+        }
+        static std::string empty;
+        return empty;
+    }
+
+    struct request
+    {
+        HTTPMethod method;
+        std::string raw_url;
+        std::string url;
+        query_string url_params;
+        ci_map headers;
+        std::string body;
+
+        void* middleware_context{};
+
+        request()
+            : method(HTTPMethod::GET)
+        {
+        }
+
+        request(HTTPMethod method, std::string raw_url, std::string url, query_string url_params, ci_map headers, std::string body)
+            : method(method), raw_url(std::move(raw_url)), url(std::move(url)), url_params(std::move(url_params)), headers(std::move(headers)), body(std::move(body))
+        {
+        }
+
+        void add_header(std::string key, std::string value)
+        {
+            headers.emplace(std::move(key), std::move(value));
+        }
+
+        const std::string& get_header_value(const std::string& key) const
+        {
+            return crow::get_header_value(headers, key);
+        }
+
+    };
+}

ext/crow/http_response.h

@@ -0,0 +1,128 @@
+#pragma once
+#include <string>
+#include <unordered_map>
+#include "json.h"
+#include "http_request.h"
+#include "ci_map.h"
+
+namespace crow
+{
+    template <typename Adaptor, typename Handler, typename ... Middlewares>
+    class Connection;
+    struct response
+    {
+        template <typename Adaptor, typename Handler, typename ... Middlewares>
+        friend class crow::Connection;
+
+        std::string body;
+        json::wvalue json_value;
+        int code{200};
+
+        // `headers' stores HTTP headers.
+        ci_map headers;
+
+        void set_header(std::string key, std::string value)
+        {
+            headers.erase(key);
+            headers.emplace(std::move(key), std::move(value));
+        }
+        void add_header(std::string key, std::string value)
+        {
+            headers.emplace(std::move(key), std::move(value));
+        }
+
+        const std::string& get_header_value(const std::string& key)
+        {
+            return crow::get_header_value(headers, key);
+        }
+
+
+        response() {}
+        explicit response(int code) : code(code) {}
+        response(std::string body) : body(std::move(body)) {}
+        response(json::wvalue&& json_value) : json_value(std::move(json_value)) 
+        {
+            json_mode();    
+        }
+        response(int code, std::string body) : body(std::move(body)), code(code) {}
+        response(const json::wvalue& json_value) : body(json::dump(json_value)) 
+        {
+            json_mode();
+        }
+        response(int code, const json::wvalue& json_value) : code(code), body(json::dump(json_value))
+        {
+            json_mode();
+        }
+
+        response(response&& r)
+        {
+            *this = std::move(r);
+        }
+
+        response& operator = (const response& r) = delete;
+
+        response& operator = (response&& r) noexcept
+        {
+            body = std::move(r.body);
+            json_value = std::move(r.json_value);
+            code = r.code;
+            headers = std::move(r.headers);
+            completed_ = r.completed_;
+            return *this;
+        }
+
+        bool is_completed() const noexcept
+        {
+            return completed_;
+        }
+
+        void clear()
+        {
+            body.clear();
+            json_value.clear();
+            code = 200;
+            headers.clear();
+            completed_ = false;
+        }
+
+        void write(const std::string& body_part)
+        {
+            body += body_part;
+        }
+
+        void end()
+        {
+            if (!completed_)
+            {
+                completed_ = true;
+                
+                if (complete_request_handler_)
+                {
+                    complete_request_handler_();
+                }
+            }
+        }
+
+        void end(const std::string& body_part)
+        {
+            body += body_part;
+            end();
+        }
+
+        bool is_alive()
+        {
+            return is_alive_helper_ && is_alive_helper_();
+        }
+
+        private:
+            bool completed_{};
+            std::function<void()> complete_request_handler_;
+            std::function<bool()> is_alive_helper_;
+            
+            //In case of a JSON object, set the Content-Type header
+            void json_mode()
+            {
+                set_header("Content-Type", "application/json");
+            }
+    };
+}

ext/crow/http_server.h

@@ -0,0 +1,184 @@
+#pragma once
+
+#include <boost/date_time/posix_time/posix_time.hpp>
+#include <boost/asio.hpp>
+#ifdef CROW_ENABLE_SSL
+#include <boost/asio/ssl.hpp>
+#endif
+#include <cstdint>
+#include <atomic>
+#include <future>
+#include <vector>
+
+#include <memory>
+
+#include "http_connection.h"
+#include "logging.h"
+#include "dumb_timer_queue.h"
+
+namespace crow
+{
+    using namespace boost;
+    using tcp = asio::ip::tcp;
+    
+    template <typename Handler, typename Adaptor = SocketAdaptor, typename ... Middlewares>
+    class Server
+    {
+    public:
+        Server(Handler* handler, uint16_t port, std::tuple<Middlewares...>* middlewares = nullptr, uint16_t concurrency = 1, typename Adaptor::context* adaptor_ctx = nullptr)
+            : acceptor_(io_service_, tcp::endpoint(asio::ip::address(), port)), 
+            signals_(io_service_, SIGINT, SIGTERM),
+            handler_(handler), 
+            concurrency_(concurrency),
+            port_(port),
+            middlewares_(middlewares),
+            adaptor_ctx_(adaptor_ctx)
+        {
+        }
+
+        void run()
+        {
+            if (concurrency_ < 0)
+                concurrency_ = 1;
+
+            for(int i = 0; i < concurrency_;  i++)
+                io_service_pool_.emplace_back(new boost::asio::io_service());
+            get_cached_date_str_pool_.resize(concurrency_);
+            timer_queue_pool_.resize(concurrency_);
+
+            std::vector<std::future<void>> v;
+            for(uint16_t i = 0; i < concurrency_; i ++)
+                v.push_back(
+                        std::async(std::launch::async, [this, i]{
+
+                            // thread local date string get function
+                            auto last = std::chrono::steady_clock::now();
+
+                            std::string date_str;
+                            auto update_date_str = [&]
+                            {
+                                auto last_time_t = time(0);
+                                tm my_tm;
+
+#ifdef _MSC_VER
+                                gmtime_s(&my_tm, &last_time_t);
+#else
+                                gmtime_r(&last_time_t, &my_tm);
+#endif
+                                date_str.resize(100);
+                                size_t date_str_sz = strftime(&date_str[0], 99, "%a, %d %b %Y %H:%M:%S GMT", &my_tm);
+                                date_str.resize(date_str_sz);
+                            };
+                            update_date_str();
+                            get_cached_date_str_pool_[i] = [&]()->std::string
+                            {
+                                if (std::chrono::steady_clock::now() - last >= std::chrono::seconds(1))
+                                {
+                                    last = std::chrono::steady_clock::now();
+                                    update_date_str();
+                                }
+                                return date_str;
+                            };
+
+                            // initializing timer queue
+                            detail::dumb_timer_queue timer_queue;
+                            timer_queue_pool_[i] = &timer_queue;
+
+                            timer_queue.set_io_service(*io_service_pool_[i]);
+                            boost::asio::deadline_timer timer(*io_service_pool_[i]);
+                            timer.expires_from_now(boost::posix_time::seconds(1));
+
+                            std::function<void(const boost::system::error_code& ec)> handler;
+                            handler = [&](const boost::system::error_code& ec){
+                                if (ec)
+                                    return;
+                                timer_queue.process();
+                                timer.expires_from_now(boost::posix_time::seconds(1));
+                                timer.async_wait(handler);
+                            };
+                            timer.async_wait(handler);
+
+                            io_service_pool_[i]->run();
+                        }));
+            CROW_LOG_INFO << server_name_ << " server is running, local port " << port_;
+
+            signals_.async_wait(
+                [&](const boost::system::error_code& error, int signal_number){
+                    stop();
+                });
+
+            for (int i = 0; i < concurrency_; i++)
+            {
+                while (timer_queue_pool_[i] == nullptr)
+                    std::this_thread::yield();
+            }
+
+            do_accept();
+
+            std::thread([this]{
+                io_service_.run();
+                CROW_LOG_INFO << "Exiting.";
+            }).join();
+        }
+
+        void stop()
+        {
+            io_service_.stop();
+            for(auto& io_service:io_service_pool_)
+                io_service->stop();
+        }
+
+    private:
+        asio::io_service& pick_io_service()
+        {
+            // TODO load balancing
+            roundrobin_index_++;
+            if (roundrobin_index_ >= io_service_pool_.size())
+                roundrobin_index_ = 0;
+            return *io_service_pool_[roundrobin_index_];
+        }
+
+        void do_accept()
+        {
+            asio::io_service& is = pick_io_service();
+            auto p = new Connection<Adaptor, Handler, Middlewares...>(
+                is, handler_, server_name_, middlewares_,
+                get_cached_date_str_pool_[roundrobin_index_], *timer_queue_pool_[roundrobin_index_],
+                adaptor_ctx_);
+            acceptor_.async_accept(p->socket(), 
+                [this, p, &is](boost::system::error_code ec)
+                {
+                    if (!ec)
+                    {
+                        is.post([p]
+                        {
+                            p->start();
+                        });
+                    }
+                    do_accept();
+                });
+        }
+
+    private:
+        asio::io_service io_service_;
+        std::vector<std::unique_ptr<asio::io_service>> io_service_pool_;
+        std::vector<detail::dumb_timer_queue*> timer_queue_pool_;
+        std::vector<std::function<std::string()>> get_cached_date_str_pool_;
+        tcp::acceptor acceptor_;
+        boost::asio::signal_set signals_;
+
+        Handler* handler_;
+        uint16_t concurrency_{1};
+        std::string server_name_ = "Crow/0.1";
+        uint16_t port_;
+        unsigned int roundrobin_index_{};
+
+        std::tuple<Middlewares...>* middlewares_;
+
+#ifdef CROW_ENABLE_SSL
+        bool use_ssl_{false};
+        boost::asio::ssl::context ssl_context_{boost::asio::ssl::context::sslv23};
+#endif
+        typename Adaptor::context* adaptor_ctx_;
+    };
+}

ext/crow/logging.h

@@ -0,0 +1,134 @@
+#pragma once
+
+#include <string>
+#include <cstdio>
+#include <cstdlib>
+#include <ctime>
+#include <iostream>
+#include <sstream>
+
+#include "settings.h"
+
+namespace crow
+{
+    enum class LogLevel
+    {
+        DEBUG,
+        INFO,
+        WARNING,
+        ERROR,
+        CRITICAL,
+    };
+
+    class ILogHandler {
+        public:
+            virtual void log(std::string message, LogLevel level) = 0;
+    };
+
+    class CerrLogHandler : public ILogHandler {
+        public:
+            void log(std::string message, LogLevel level) override {
+                std::cerr << message;
+            }
+    };
+
+    class logger {
+
+        private:
+            //
+            static std::string timestamp()
+            {
+                char date[32];
+                time_t t = time(0);
+
+                tm my_tm;
+
+#ifdef _MSC_VER
+                gmtime_s(&my_tm, &t);
+#else
+                gmtime_r(&t, &my_tm);
+#endif
+
+                size_t sz = strftime(date, sizeof(date), "%Y-%m-%d %H:%M:%S", &my_tm);
+                return std::string(date, date+sz);
+            }
+
+        public:
+
+
+            logger(std::string prefix, LogLevel level) : level_(level) {
+    #ifdef CROW_ENABLE_LOGGING
+                    stringstream_ << "(" << timestamp() << ") [" << prefix << "] ";
+    #endif
+
+            }
+            ~logger() {
+    #ifdef CROW_ENABLE_LOGGING
+                if(level_ >= get_current_log_level()) {
+                    stringstream_ << std::endl;
+                    get_handler_ref()->log(stringstream_.str(), level_);
+                }
+    #endif
+            }
+
+            //
+            template <typename T>
+            logger& operator<<(T const &value) {
+
+    #ifdef CROW_ENABLE_LOGGING
+                if(level_ >= get_current_log_level()) {
+                    stringstream_ << value;
+                }
+    #endif
+                return *this;
+            }
+
+            //
+            static void setLogLevel(LogLevel level) {
+                get_log_level_ref() = level;
+            }
+
+            static void setHandler(ILogHandler* handler) {
+                get_handler_ref() = handler;
+            }
+
+            static LogLevel get_current_log_level() {
+                return get_log_level_ref();
+            }
+
+        private:
+            //
+            static LogLevel& get_log_level_ref()
+            {
+                static LogLevel current_level = (LogLevel)CROW_LOG_LEVEL;
+                return current_level;
+            }
+            static ILogHandler*& get_handler_ref()
+            {
+                static CerrLogHandler default_handler;
+                static ILogHandler* current_handler = &default_handler;
+                return current_handler;
+            }
+
+            //
+            std::ostringstream stringstream_;
+            LogLevel level_;
+    };
+}
+
+#define CROW_LOG_CRITICAL   \
+        if (crow::logger::get_current_log_level() <= crow::LogLevel::CRITICAL) \
+            crow::logger("CRITICAL", crow::LogLevel::CRITICAL)
+#define CROW_LOG_ERROR      \
+        if (crow::logger::get_current_log_level() <= crow::LogLevel::ERROR) \
+            crow::logger("ERROR   ", crow::LogLevel::ERROR)
+#define CROW_LOG_WARNING    \
+        if (crow::logger::get_current_log_level() <= crow::LogLevel::WARNING) \
+            crow::logger("WARNING ", crow::LogLevel::WARNING)
+#define CROW_LOG_INFO       \
+        if (crow::logger::get_current_log_level() <= crow::LogLevel::INFO) \
+            crow::logger("INFO    ", crow::LogLevel::INFO)
+#define CROW_LOG_DEBUG      \
+        if (crow::logger::get_current_log_level() <= crow::LogLevel::DEBUG) \
+            crow::logger("DEBUG   ", crow::LogLevel::DEBUG)
+

ext/crow/middleware.h

@@ -0,0 +1,174 @@
+#pragma once
+#include <boost/algorithm/string/trim.hpp>
+#include "http_request.h"
+#include "http_response.h"
+
+namespace crow
+{
+    // Any middleware requires following 3 members:
+
+    // struct context;
+    //      storing data for the middleware; can be read from another middleware or handlers
+
+    // before_handle
+    //      called before handling the request.
+    //      if res.end() is called, the operation is halted. 
+    //      (still call after_handle of this middleware)
+    //      2 signatures:
+    //      void before_handle(request& req, response& res, context& ctx)
+    //          if you only need to access this middlewares context.
+    //      template <typename AllContext>
+    //      void before_handle(request& req, response& res, context& ctx, AllContext& all_ctx)
+    //          you can access another middlewares' context by calling `all_ctx.template get<MW>()'
+    //          ctx == all_ctx.template get<CurrentMiddleware>()
+
+    // after_handle
+    //      called after handling the request.
+    //      void after_handle(request& req, response& res, context& ctx)
+    //      template <typename AllContext>
+    //      void after_handle(request& req, response& res, context& ctx, AllContext& all_ctx)
+
+    struct CookieParser
+    {
+        struct context
+        {
+            std::unordered_map<std::string, std::string> jar;
+            std::unordered_map<std::string, std::string> cookies_to_add;
+
+            std::string get_cookie(const std::string& key)
+            {
+                if (jar.count(key))
+                    return jar[key];
+                return {};
+            }
+
+            void set_cookie(const std::string& key, const std::string& value)
+            {
+                cookies_to_add.emplace(key, value);
+            }
+        };
+
+        void before_handle(request& req, response& res, context& ctx)
+        {
+            int count = req.headers.count("Cookie");
+            if (!count)
+                return;
+            if (count > 1)
+            {
+                res.code = 400;
+                res.end();
+                return;
+            }
+            std::string cookies = req.get_header_value("Cookie");
+            size_t pos = 0;
+            while(pos < cookies.size())
+            {
+                size_t pos_equal = cookies.find('=', pos);
+                if (pos_equal == cookies.npos)
+                    break;
+                std::string name = cookies.substr(pos, pos_equal-pos);
+                boost::trim(name);
+                pos = pos_equal+1;
+                while(pos < cookies.size() && cookies[pos] == ' ') pos++;
+                if (pos == cookies.size())
+                    break;
+
+                std::string value;
+
+                if (cookies[pos] == '"')
+                {
+                    int dquote_meet_count = 0;
+                    pos ++;
+                    size_t pos_dquote = pos-1;
+                    do
+                    {
+                        pos_dquote = cookies.find('"', pos_dquote+1);
+                        dquote_meet_count ++;
+                    } while(pos_dquote < cookies.size() && cookies[pos_dquote-1] == '\\');
+                    if (pos_dquote == cookies.npos)
+                        break;
+
+                    if (dquote_meet_count == 1)
+                        value = cookies.substr(pos, pos_dquote - pos);
+                    else
+                    {
+                        value.clear();
+                        value.reserve(pos_dquote-pos);
+                        for(size_t p = pos; p < pos_dquote; p++)
+                        {
+                            // FIXME minimal escaping
+                            if (cookies[p] == '\\' && p + 1 < pos_dquote)
+                            {
+                                p++;
+                                if (cookies[p] == '\\' || cookies[p] == '"')
+                                    value += cookies[p];
+                                else
+                                {
+                                    value += '\\';
+                                    value += cookies[p];
+                                }
+                            }
+                            else
+                                value += cookies[p];
+                        }
+                    }
+
+                    ctx.jar.emplace(std::move(name), std::move(value));
+                    pos = cookies.find(";", pos_dquote+1);
+                    if (pos == cookies.npos)
+                        break;
+                    pos++;
+                    while(pos < cookies.size() && cookies[pos] == ' ') pos++;
+                    if (pos == cookies.size())
+                        break;
+                }
+                else
+                {
+                    size_t pos_semicolon = cookies.find(';', pos);
+                    value = cookies.substr(pos, pos_semicolon - pos);
+                    boost::trim(value);
+                    ctx.jar.emplace(std::move(name), std::move(value));
+                    pos = pos_semicolon;
+                    if (pos == cookies.npos)
+                        break;
+                    pos ++;
+                    while(pos < cookies.size() && cookies[pos] == ' ') pos++;
+                    if (pos == cookies.size())
+                        break;
+                }
+            }
+        }
+
+        void after_handle(request& req, response& res, context& ctx)
+        {
+            for(auto& cookie:ctx.cookies_to_add)
+            {
+                res.add_header("Set-Cookie", cookie.first + "=" + cookie.second);
+            }
+        }
+    };
+
+    /*
+    App<CookieParser, AnotherJarMW> app;
+    A B C
+    A::context
+        int aa;
+
+    ctx1 : public A::context
+    ctx2 : public ctx1, public B::context
+    ctx3 : public ctx2, public C::context
+
+    C depends on A
+
+    C::handle
+        context.aaa
+
+    App::context : private CookieParser::contetx, ... 
+    {
+        jar
+
+    }
+
+    SimpleApp
+    */
+}

ext/crow/middleware_context.h

@@ -0,0 +1,59 @@
+#pragma once
+
+#include "utility.h"
+#include "http_request.h"
+#include "http_response.h"
+
+namespace crow
+{
+    namespace detail
+    {
+        template <typename ... Middlewares>
+        struct partial_context
+            : public black_magic::pop_back<Middlewares...>::template rebind<partial_context>
+            , public black_magic::last_element_type<Middlewares...>::type::context
+        {
+            using parent_context = typename black_magic::pop_back<Middlewares...>::template rebind<::crow::detail::partial_context>;
+            template <int N>
+            using partial = typename std::conditional<N == sizeof...(Middlewares)-1, partial_context, typename parent_context::template partial<N>>::type;
+
+            template <typename T> 
+            typename T::context& get()
+            {
+                return static_cast<typename T::context&>(*this);
+            }
+        };
+
+        template <>
+        struct partial_context<>
+        {
+            template <int>
+            using partial = partial_context;
+        };
+
+        template <int N, typename Context, typename Container, typename CurrentMW, typename ... Middlewares>
+        bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx);
+
+        template <typename ... Middlewares>
+        struct context : private partial_context<Middlewares...>
+        //struct context : private Middlewares::context... // simple but less type-safe
+        {
+            template <int N, typename Context, typename Container>
+            friend typename std::enable_if<(N==0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res);
+            template <int N, typename Context, typename Container>
+            friend typename std::enable_if<(N>0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res);
+
+            template <int N, typename Context, typename Container, typename CurrentMW, typename ... Middlewares2>
+            friend bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx);
+
+            template <typename T> 
+            typename T::context& get()
+            {
+                return static_cast<typename T::context&>(*this);
+            }
+
+            template <int N>
+            using partial = typename partial_context<Middlewares...>::template partial<N>;
+        };
+    }
+}

ext/crow/mustache.h

@@ -0,0 +1,559 @@
+#pragma once
+#include <string>
+#include <vector>
+#include <fstream>
+#include <iterator>
+#include <functional>
+#include "json.h"
+namespace crow
+{
+    namespace mustache
+    {
+        using context = json::wvalue;
+
+        template_t load(const std::string& filename);
+
+        class invalid_template_exception : public std::exception
+        {
+            public:
+            invalid_template_exception(const std::string& msg)
+                : msg("crow::mustache error: " + msg)
+            {
+            }
+            virtual const char* what() const throw()
+            {
+                return msg.c_str();
+            }
+            std::string msg;
+        };
+
+        enum class ActionType
+        {
+            Ignore,
+            Tag,
+            UnescapeTag,
+            OpenBlock,
+            CloseBlock,
+            ElseBlock,
+            Partial,
+        };
+
+        struct Action
+        {
+            int start;
+            int end;
+            int pos;
+            ActionType t;
+            Action(ActionType t, int start, int end, int pos = 0) 
+                : start(start), end(end), pos(pos), t(t)
+            {}
+        };
+
+        class template_t 
+        {
+        public:
+            template_t(std::string body)
+                : body_(std::move(body))
+            {
+                // {{ {{# {{/ {{^ {{! {{> {{=
+                parse();
+            }
+
+        private:
+            std::string tag_name(const Action& action)
+            {
+                return body_.substr(action.start, action.end - action.start);
+            }
+            auto find_context(const std::string& name, const std::vector<context*>& stack)->std::pair<bool, context&>
+            {
+                if (name == ".")
+                {
+                    return {true, *stack.back()};
+                }
+                int dotPosition = name.find(".");
+                if (dotPosition == (int)name.npos)
+                {
+                    for(auto it = stack.rbegin(); it != stack.rend(); ++it)
+                    {
+                        if ((*it)->t() == json::type::Object)
+                        {
+                            if ((*it)->count(name))
+                                return {true, (**it)[name]};
+                        }
+                    }
+                }
+                else
+                {
+                    std::vector<int> dotPositions;
+                    dotPositions.push_back(-1);
+                    while(dotPosition != (int)name.npos)
+                    {
+                        dotPositions.push_back(dotPosition);
+                        dotPosition = name.find(".", dotPosition+1);
+                    }
+                    dotPositions.push_back(name.size());
+                    std::vector<std::string> names;
+                    names.reserve(dotPositions.size()-1);
+                    for(int i = 1; i < (int)dotPositions.size(); i ++)
+                        names.emplace_back(name.substr(dotPositions[i-1]+1, dotPositions[i]-dotPositions[i-1]-1));
+
+                    for(auto it = stack.rbegin(); it != stack.rend(); ++it)
+                    {
+                        context* view = *it;
+                        bool found = true;
+                        for(auto jt = names.begin(); jt != names.end(); ++jt)
+                        {
+                            if (view->t() == json::type::Object &&
+                                view->count(*jt))
+                            {
+                                view = &(*view)[*jt];
+                            }
+                            else
+                            {
+                                found = false;
+                                break;
+                            }
+                        }
+                        if (found)
+                            return {true, *view};
+                    }
+
+                }
+
+                static json::wvalue empty_str;
+                empty_str = "";
+                return {false, empty_str};
+            }
+
+            void escape(const std::string& in, std::string& out)
+            {
+                out.reserve(out.size() + in.size());
+                for(auto it = in.begin(); it != in.end(); ++it)
+                {
+                    switch(*it)
+                    {
+                        case '&': out += "&amp;"; break;
+                        case '<': out += "&lt;"; break;
+                        case '>': out += "&gt;"; break;
+                        case '"': out += "&quot;"; break;
+                        case '\'': out += "&#39;"; break;
+                        case '/': out += "&#x2F;"; break;
+                        default: out += *it; break;
+                    }
+                }
+            }
+
+            void render_internal(int actionBegin, int actionEnd, std::vector<context*>& stack, std::string& out, int indent)
+            {
+                int current = actionBegin;
+
+                if (indent)
+                    out.insert(out.size(), indent, ' ');
+
+                while(current < actionEnd)
+                {
+                    auto& fragment = fragments_[current];
+                    auto& action = actions_[current];
+                    render_fragment(fragment, indent, out);
+                    switch(action.t)
+                    {
+                        case ActionType::Ignore:
+                            // do nothing
+                            break;
+                        case ActionType::Partial:
+                            {
+                                std::string partial_name = tag_name(action);
+                                auto partial_templ = load(partial_name);
+                                int partial_indent = action.pos;
+                                partial_templ.render_internal(0, partial_templ.fragments_.size()-1, stack, out, partial_indent?indent+partial_indent:0);
+                            }
+                            break;
+                        case ActionType::UnescapeTag:
+                        case ActionType::Tag:
+                            {
+                                auto optional_ctx = find_context(tag_name(action), stack);
+                                auto& ctx = optional_ctx.second;
+                                switch(ctx.t())
+                                {
+                                    case json::type::Number:
+                                        out += json::dump(ctx);
+                                        break;
+                                    case json::type::String:
+                                        if (action.t == ActionType::Tag)
+                                            escape(ctx.s, out);
+                                        else
+                                            out += ctx.s;
+                                        break;
+                                    default:
+                                        throw std::runtime_error("not implemented tag type" + boost::lexical_cast<std::string>((int)ctx.t()));
+                                }
+                            }
+                            break;
+                        case ActionType::ElseBlock:
+                            {
+                                static context nullContext;
+                                auto optional_ctx = find_context(tag_name(action), stack);
+                                if (!optional_ctx.first)
+                                {
+                                    stack.emplace_back(&nullContext);
+                                    break;
+                                }
+
+                                auto& ctx = optional_ctx.second;
+                                switch(ctx.t())
+                                {
+                                    case json::type::List:
+                                        if (ctx.l && !ctx.l->empty())
+                                            current = action.pos;
+                                        else
+                                            stack.emplace_back(&nullContext);
+                                        break;
+                                    case json::type::False:
+                                    case json::type::Null:
+                                        stack.emplace_back(&nullContext);
+                                        break;
+                                    default:
+                                        current = action.pos;
+                                        break;
+                                }
+                                break;
+                            }
+                        case ActionType::OpenBlock:
+                            {
+                                auto optional_ctx = find_context(tag_name(action), stack);
+                                if (!optional_ctx.first)
+                                {
+                                    current = action.pos;
+                                    break;
+                                }
+
+                                auto& ctx = optional_ctx.second;
+                                switch(ctx.t())
+                                {
+                                    case json::type::List:
+                                        if (ctx.l)
+                                            for(auto it = ctx.l->begin(); it != ctx.l->end(); ++it)
+                                            {
+                                                stack.push_back(&*it);
+                                                render_internal(current+1, action.pos, stack, out, indent);
+                                                stack.pop_back();
+                                            }
+                                        current = action.pos;
+                                        break;
+                                    case json::type::Number:
+                                    case json::type::String:
+                                    case json::type::Object:
+                                    case json::type::True:
+                                        stack.push_back(&ctx);
+                                        break;
+                                    case json::type::False:
+                                    case json::type::Null:
+                                        current = action.pos;
+                                        break;
+                                    default:
+                                        throw std::runtime_error("{{#: not implemented context type: " + boost::lexical_cast<std::string>((int)ctx.t()));
+                                        break;
+                                }
+                                break;
+                            }
+                        case ActionType::CloseBlock:
+                            stack.pop_back();
+                            break;
+                        default:
+                            throw std::runtime_error("not implemented " + boost::lexical_cast<std::string>((int)action.t));
+                    }
+                    current++;
+                }
+                auto& fragment = fragments_[actionEnd];
+                render_fragment(fragment, indent, out);
+            }
+            void render_fragment(const std::pair<int, int> fragment, int indent, std::string& out)
+            {
+                if (indent)
+                {
+                    for(int i = fragment.first; i < fragment.second; i ++)
+                    {
+                        out += body_[i];
+                        if (body_[i] == '\n' && i+1 != (int)body_.size())
+                            out.insert(out.size(), indent, ' ');
+                    }
+                }
+                else
+                    out.insert(out.size(), body_, fragment.first, fragment.second-fragment.first);
+            }
+        public:
+            std::string render()
+            {
+                context empty_ctx;
+                std::vector<context*> stack;
+                stack.emplace_back(&empty_ctx);
+
+                std::string ret;
+                render_internal(0, fragments_.size()-1, stack, ret, 0);
+                return ret;
+            }
+            std::string render(context& ctx)
+            {
+                std::vector<context*> stack;
+                stack.emplace_back(&ctx);
+
+                std::string ret;
+                render_internal(0, fragments_.size()-1, stack, ret, 0);
+                return ret;
+            }
+
+        private:
+
+            void parse()
+            {
+                std::string tag_open = "{{";
+                std::string tag_close = "}}";
+
+                std::vector<int> blockPositions;
+                
+                size_t current = 0;
+                while(1)
+                {
+                    size_t idx = body_.find(tag_open, current);
+                    if (idx == body_.npos)
+                    {
+                        fragments_.emplace_back(current, body_.size());
+                        actions_.emplace_back(ActionType::Ignore, 0, 0);
+                        break;
+                    }
+                    fragments_.emplace_back(current, idx);
+
+                    idx += tag_open.size();
+                    size_t endIdx = body_.find(tag_close, idx);
+                    if (endIdx == idx)
+                    {
+                        throw invalid_template_exception("empty tag is not allowed");
+                    }
+                    if (endIdx == body_.npos)
+                    {
+                        // error, no matching tag
+                        throw invalid_template_exception("not matched opening tag");
+                    }
+                    current = endIdx + tag_close.size();
+                    switch(body_[idx])
+                    {
+                        case '#':
+                            idx++;
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx-1] == ' ') endIdx--;
+                            blockPositions.emplace_back(actions_.size());
+                            actions_.emplace_back(ActionType::OpenBlock, idx, endIdx);
+                            break;
+                        case '/':
+                            idx++;
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx-1] == ' ') endIdx--;
+                            {
+                                auto& matched = actions_[blockPositions.back()];
+                                if (body_.compare(idx, endIdx-idx, 
+                                        body_, matched.start, matched.end - matched.start) != 0)
+                                {
+                                    throw invalid_template_exception("not matched {{# {{/ pair: " + 
+                                        body_.substr(matched.start, matched.end - matched.start) + ", " + 
+                                        body_.substr(idx, endIdx-idx));
+                                }
+                                matched.pos = actions_.size();
+                            }
+                            actions_.emplace_back(ActionType::CloseBlock, idx, endIdx, blockPositions.back());
+                            blockPositions.pop_back();
+                            break;
+                        case '^':
+                            idx++;
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx-1] == ' ') endIdx--;
+                            blockPositions.emplace_back(actions_.size());
+                            actions_.emplace_back(ActionType::ElseBlock, idx, endIdx);
+                            break;
+                        case '!':
+                            // do nothing action
+                            actions_.emplace_back(ActionType::Ignore, idx+1, endIdx);
+                            break;
+                        case '>': // partial
+                            idx++;
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx-1] == ' ') endIdx--;
+                            actions_.emplace_back(ActionType::Partial, idx, endIdx);
+                            break;
+                        case '{':
+                            if (tag_open != "{{" || tag_close != "}}")
+                                throw invalid_template_exception("cannot use triple mustache when delimiter changed");
+
+                            idx ++;
+                            if (body_[endIdx+2] != '}')
+                            {
+                                throw invalid_template_exception("{{{: }}} not matched");
+                            }
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx-1] == ' ') endIdx--;
+                            actions_.emplace_back(ActionType::UnescapeTag, idx, endIdx);
+                            current++;
+                            break;
+                        case '&':
+                            idx ++;
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx-1] == ' ') endIdx--;
+                            actions_.emplace_back(ActionType::UnescapeTag, idx, endIdx);
+                            break;
+                        case '=':
+                            // tag itself is no-op
+                            idx ++;
+                            actions_.emplace_back(ActionType::Ignore, idx, endIdx);
+                            endIdx --;
+                            if (body_[endIdx] != '=')
+                                throw invalid_template_exception("{{=: not matching = tag: "+body_.substr(idx, endIdx-idx));
+                            endIdx --;
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx] == ' ') endIdx--;
+                            endIdx++;
+                            {
+                                bool succeeded = false;
+                                for(size_t i = idx; i < endIdx; i++)
+                                {
+                                    if (body_[i] == ' ')
+                                    {
+                                        tag_open = body_.substr(idx, i-idx);
+                                        while(body_[i] == ' ') i++;
+                                        tag_close = body_.substr(i, endIdx-i);
+                                        if (tag_open.empty())
+                                            throw invalid_template_exception("{{=: empty open tag");
+                                        if (tag_close.empty())
+                                            throw invalid_template_exception("{{=: empty close tag");
+
+                                        if (tag_close.find(" ") != tag_close.npos)
+                                            throw invalid_template_exception("{{=: invalid open/close tag: "+tag_open+" " + tag_close);
+                                        succeeded = true;
+                                        break;
+                                    }
+                                }
+                                if (!succeeded)
+                                    throw invalid_template_exception("{{=: cannot find space between new open/close tags");
+                            }
+                            break;
+                        default:
+                            // normal tag case;
+                            while(body_[idx] == ' ') idx++;
+                            while(body_[endIdx-1] == ' ') endIdx--;
+                            actions_.emplace_back(ActionType::Tag, idx, endIdx);
+                            break;
+                    }
+                }
+
+                // removing standalones
+                for(int i = actions_.size()-2; i >= 0; i --)
+                {
+                    if (actions_[i].t == ActionType::Tag || actions_[i].t == ActionType::UnescapeTag)
+                        continue;
+                    auto& fragment_before = fragments_[i];
+                    auto& fragment_after = fragments_[i+1];
+                    bool is_last_action = i == (int)actions_.size()-2;
+                    bool all_space_before = true;
+                    int j, k;
+                    for(j = fragment_before.second-1;j >= fragment_before.first;j--)
+                    {
+                        if (body_[j] != ' ')
+                        {
+                            all_space_before = false;
+                            break;
+                        }
+                    }
+                    if (all_space_before && i > 0)
+                        continue;
+                    if (!all_space_before && body_[j] != '\n')
+                        continue;
+                    bool all_space_after = true;
+                    for(k = fragment_after.first; k < (int)body_.size() && k < fragment_after.second; k ++)
+                    {
+                        if (body_[k] != ' ')
+                        {
+                            all_space_after = false;
+                            break;
+                        }
+                    }
+                    if (all_space_after && !is_last_action)
+                        continue;
+                    if (!all_space_after && 
+                            !(
+                                body_[k] == '\n' 
+                            || 
+                                (body_[k] == '\r' && 
+                                k + 1 < (int)body_.size() && 
+                                body_[k+1] == '\n')))
+                        continue;
+                    if (actions_[i].t == ActionType::Partial)
+                    {
+                        actions_[i].pos = fragment_before.second - j - 1;
+                    }
+                    fragment_before.second = j+1;
+                    if (!all_space_after)
+                    {
+                        if (body_[k] == '\n')
+                            k++;
+                        else 
+                            k += 2;
+                        fragment_after.first = k;
+                    }
+                }
+            }
+            
+            std::vector<std::pair<int,int>> fragments_;
+            std::vector<Action> actions_;
+            std::string body_;
+        };
+
+        inline template_t compile(const std::string& body)
+        {
+            return template_t(body);
+        }
+        namespace detail
+        {
+            inline std::string& get_template_base_directory_ref()
+            {
+                static std::string template_base_directory = "templates";
+                return template_base_directory;
+            }
+        }
+
+        inline std::string default_loader(const std::string& filename)
+        {
+            std::ifstream inf(detail::get_template_base_directory_ref() + filename);
+            if (!inf)
+                return {};
+            return {std::istreambuf_iterator<char>(inf), std::istreambuf_iterator<char>()};
+        }
+
+        namespace detail
+        {
+            inline std::function<std::string (std::string)>& get_loader_ref()
+            {
+                static std::function<std::string (std::string)> loader = default_loader;
+                return loader;
+            }
+        }
+
+        inline void set_base(const std::string& path)
+        {
+            auto& base = detail::get_template_base_directory_ref();
+            base = path;
+            if (base.back() != '\\' && 
+                base.back() != '/')
+            {
+                base += '/';
+            }
+        }
+
+        inline void set_loader(std::function<std::string(std::string)> loader)
+        {
+            detail::get_loader_ref() = std::move(loader);
+        }
+
+        inline template_t load(const std::string& filename)
+        {
+            return compile(detail::get_loader_ref()(filename));
+        }
+    }
+}

ext/crow/parser.h

@@ -0,0 +1,163 @@
+#pragma once
+
+#include <string>
+#include <unordered_map>
+#include <boost/algorithm/string.hpp>
+#include <boost/tokenizer.hpp>
+#include <algorithm>
+
+#include "http_parser_merged.h"
+#include "http_request.h"
+
+namespace crow
+{
+    template <typename Handler>
+    struct HTTPParser : public http_parser
+    {
+        static int on_message_begin(http_parser* self_)
+        {
+            HTTPParser* self = static_cast<HTTPParser*>(self_);
+            self->clear();
+            return 0;
+        }
+        static int on_url(http_parser* self_, const char* at, size_t length)
+        {
+            HTTPParser* self = static_cast<HTTPParser*>(self_);
+            self->raw_url.insert(self->raw_url.end(), at, at+length);
+            return 0;
+        }
+        static int on_header_field(http_parser* self_, const char* at, size_t length)
+        {
+            HTTPParser* self = static_cast<HTTPParser*>(self_);
+            switch (self->header_building_state)
+            {
+                case 0:
+                    if (!self->header_value.empty())
+                    {
+                        self->headers.emplace(std::move(self->header_field), std::move(self->header_value));
+                    }
+                    self->header_field.assign(at, at+length);
+                    self->header_building_state = 1;
+                    break;
+                case 1:
+                    self->header_field.insert(self->header_field.end(), at, at+length);
+                    break;
+            }
+            return 0;
+        }
+        static int on_header_value(http_parser* self_, const char* at, size_t length)
+        {
+            HTTPParser* self = static_cast<HTTPParser*>(self_);
+            switch (self->header_building_state)
+            {
+                case 0:
+                    self->header_value.insert(self->header_value.end(), at, at+length);
+                    break;
+                case 1:
+                    self->header_building_state = 0;
+                    self->header_value.assign(at, at+length);
+                    break;
+            }
+            return 0;
+        }
+        static int on_headers_complete(http_parser* self_)
+        {
+            HTTPParser* self = static_cast<HTTPParser*>(self_);
+            if (!self->header_field.empty())
+            {
+                self->headers.emplace(std::move(self->header_field), std::move(self->header_value));
+            }
+            self->process_header();
+            return 0;
+        }
+        static int on_body(http_parser* self_, const char* at, size_t length)
+        {
+            HTTPParser* self = static_cast<HTTPParser*>(self_);
+            self->body.insert(self->body.end(), at, at+length);
+            return 0;
+        }
+        static int on_message_complete(http_parser* self_)
+        {
+            HTTPParser* self = static_cast<HTTPParser*>(self_);
+
+            // url params
+            self->url = self->raw_url.substr(0, self->raw_url.find("?"));
+            self->url_params = query_string(self->raw_url);
+
+            self->process_message();
+            return 0;
+        }
+        HTTPParser(Handler* handler) :
+            handler_(handler)
+        {
+            http_parser_init(this, HTTP_REQUEST);
+        }
+
+        // return false on error
+        bool feed(const char* buffer, int length)
+        {
+            const static http_parser_settings settings_{
+                on_message_begin,
+                on_url,
+                nullptr,
+                on_header_field,
+                on_header_value,
+                on_headers_complete,
+                on_body,
+                on_message_complete,
+            };
+
+            int nparsed = http_parser_execute(this, &settings_, buffer, length);
+            return nparsed == length;
+        }
+
+        bool done()
+        {
+            return feed(nullptr, 0);
+        }
+
+        void clear()
+        {
+            url.clear();
+            raw_url.clear();
+            header_building_state = 0;
+            header_field.clear();
+            header_value.clear();
+            headers.clear();
+            url_params.clear();
+            body.clear();
+        }
+
+        void process_header()
+        {
+            handler_->handle_header();
+        }
+
+        void process_message()
+        {
+            handler_->handle();
+        }
+
+        request to_request() const
+        {
+            return request{(HTTPMethod)method, std::move(raw_url), std::move(url), std::move(url_params), std::move(headers), std::move(body)};
+        }
+
+        bool check_version(int major, int minor) const
+        {
+            return http_major == major && http_minor == minor;
+        }
+
+        std::string raw_url;
+        std::string url;
+
+        int header_building_state = 0;
+        std::string header_field;
+        std::string header_value;
+        ci_map headers;
+        query_string url_params;
+        std::string body;
+
+        Handler* handler_;
+    };
+}

ext/crow/query_string.h

@@ -0,0 +1,342 @@
+#pragma once
+
+#include <stdio.h>
+#include <string.h>
+#include <string>
+#include <vector>
+#include <iostream>
+
+// ----------------------------------------------------------------------------
+// qs_parse (modified)
+// https://github.com/bartgrantham/qs_parse
+// ----------------------------------------------------------------------------
+/*  Similar to strncmp, but handles URL-encoding for either string  */
+int qs_strncmp(const char * s, const char * qs, size_t n);
+
+
+/*  Finds the beginning of each key/value pair and stores a pointer in qs_kv.
+ *  Also decodes the value portion of the k/v pair *in-place*.  In a future
+ *  enhancement it will also have a compile-time option of sorting qs_kv
+ *  alphabetically by key.  */
+int qs_parse(char * qs, char * qs_kv[], int qs_kv_size);
+
+
+/*  Used by qs_parse to decode the value portion of a k/v pair  */
+int qs_decode(char * qs);
+
+
+/*  Looks up the value according to the key on a pre-processed query string
+ *  A future enhancement will be a compile-time option to look up the key
+ *  in a pre-sorted qs_kv array via a binary search.  */
+//char * qs_k2v(const char * key, char * qs_kv[], int qs_kv_size);
+ char * qs_k2v(const char * key, char * const * qs_kv, int qs_kv_size, int nth);
+
+
+/*  Non-destructive lookup of value, based on key.  User provides the
+ *  destinaton string and length.  */
+char * qs_scanvalue(const char * key, const char * qs, char * val, size_t val_len);
+
+// TODO: implement sorting of the qs_kv array; for now ensure it's not compiled
+#undef _qsSORTING
+
+// isxdigit _is_ available in <ctype.h>, but let's avoid another header instead
+#define CROW_QS_ISHEX(x)    ((((x)>='0'&&(x)<='9') || ((x)>='A'&&(x)<='F') || ((x)>='a'&&(x)<='f')) ? 1 : 0)
+#define CROW_QS_HEX2DEC(x)  (((x)>='0'&&(x)<='9') ? (x)-48 : ((x)>='A'&&(x)<='F') ? (x)-55 : ((x)>='a'&&(x)<='f') ? (x)-87 : 0)
+#define CROW_QS_ISQSCHR(x) ((((x)=='=')||((x)=='#')||((x)=='&')||((x)=='\0')) ? 0 : 1)
+
+inline int qs_strncmp(const char * s, const char * qs, size_t n)
+{
+    int i=0;
+    unsigned char u1, u2, unyb, lnyb;
+
+    while(n-- > 0)
+    {
+        u1 = (unsigned char) *s++;
+        u2 = (unsigned char) *qs++;
+
+        if ( ! CROW_QS_ISQSCHR(u1) ) {  u1 = '\0';  }
+        if ( ! CROW_QS_ISQSCHR(u2) ) {  u2 = '\0';  }
+
+        if ( u1 == '+' ) {  u1 = ' ';  }
+        if ( u1 == '%' ) // easier/safer than scanf
+        {
+            unyb = (unsigned char) *s++;
+            lnyb = (unsigned char) *s++;
+            if ( CROW_QS_ISHEX(unyb) && CROW_QS_ISHEX(lnyb) )
+                u1 = (CROW_QS_HEX2DEC(unyb) * 16) + CROW_QS_HEX2DEC(lnyb);
+            else
+                u1 = '\0';
+        }
+
+        if ( u2 == '+' ) {  u2 = ' ';  }
+        if ( u2 == '%' ) // easier/safer than scanf
+        {
+            unyb = (unsigned char) *qs++;
+            lnyb = (unsigned char) *qs++;
+            if ( CROW_QS_ISHEX(unyb) && CROW_QS_ISHEX(lnyb) )
+                u2 = (CROW_QS_HEX2DEC(unyb) * 16) + CROW_QS_HEX2DEC(lnyb);
+            else
+                u2 = '\0';
+        }
+
+        if ( u1 != u2 )
+            return u1 - u2;
+        if ( u1 == '\0' )
+            return 0;
+        i++;
+    }
+    if ( CROW_QS_ISQSCHR(*qs) )
+        return -1;
+    else
+        return 0;
+}
+
+
+inline int qs_parse(char * qs, char * qs_kv[], int qs_kv_size)
+{
+    int i, j;
+    char * substr_ptr;
+
+    for(i=0; i<qs_kv_size; i++)  qs_kv[i] = NULL;
+
+    // find the beginning of the k/v substrings or the fragment
+    substr_ptr = qs + strcspn(qs, "?#");
+    if (substr_ptr[0] != '\0')
+        substr_ptr++;
+    else
+        return 0; // no query or fragment
+
+    i=0;
+    while(i<qs_kv_size)
+    {
+        qs_kv[i] = substr_ptr;
+        j = strcspn(substr_ptr, "&");
+        if ( substr_ptr[j] == '\0' ) {  break;  }
+        substr_ptr += j + 1;
+        i++;
+    }
+    i++;  // x &'s -> means x iterations of this loop -> means *x+1* k/v pairs
+
+    // we only decode the values in place, the keys could have '='s in them
+    // which will hose our ability to distinguish keys from values later
+    for(j=0; j<i; j++)
+    {
+        substr_ptr = qs_kv[j] + strcspn(qs_kv[j], "=&#");
+        if ( substr_ptr[0] == '&' || substr_ptr[0] == '\0')  // blank value: skip decoding
+            substr_ptr[0] = '\0';
+        else
+            qs_decode(++substr_ptr);
+    }
+
+#ifdef _qsSORTING
+// TODO: qsort qs_kv, using qs_strncmp() for the comparison
+#endif
+
+    return i;
+}
+
+
+inline int qs_decode(char * qs)
+{
+    int i=0, j=0;
+
+    while( CROW_QS_ISQSCHR(qs[j]) )
+    {
+        if ( qs[j] == '+' ) {  qs[i] = ' ';  }
+        else if ( qs[j] == '%' ) // easier/safer than scanf
+        {
+            if ( ! CROW_QS_ISHEX(qs[j+1]) || ! CROW_QS_ISHEX(qs[j+2]) )
+            {
+                qs[i] = '\0';
+                return i;
+            }
+            qs[i] = (CROW_QS_HEX2DEC(qs[j+1]) * 16) + CROW_QS_HEX2DEC(qs[j+2]);
+            j+=2;
+        }
+        else
+        {
+            qs[i] = qs[j];
+        }
+        i++;  j++;
+    }
+    qs[i] = '\0';
+
+    return i;
+}
+
+
+inline char * qs_k2v(const char * key, char * const * qs_kv, int qs_kv_size, int nth = 0)
+{
+    int i;
+    size_t key_len, skip;
+
+    key_len = strlen(key);
+
+#ifdef _qsSORTING
+// TODO: binary search for key in the sorted qs_kv
+#else  // _qsSORTING
+    for(i=0; i<qs_kv_size; i++)
+    {
+        // we rely on the unambiguous '=' to find the value in our k/v pair
+        if ( qs_strncmp(key, qs_kv[i], key_len) == 0 )
+        {
+            skip = strcspn(qs_kv[i], "=");
+            if ( qs_kv[i][skip] == '=' )
+                skip++;
+            // return (zero-char value) ? ptr to trailing '\0' : ptr to value
+            if(nth == 0)
+                return qs_kv[i] + skip;
+            else 
+                --nth;
+        }
+    }
+#endif  // _qsSORTING
+
+    return NULL;
+}
+
+
+inline char * qs_scanvalue(const char * key, const char * qs, char * val, size_t val_len)
+{
+    size_t i, key_len;
+    const char * tmp;
+
+    // find the beginning of the k/v substrings
+    if ( (tmp = strchr(qs, '?')) != NULL )
+        qs = tmp + 1;
+
+    key_len = strlen(key);
+    while(qs[0] != '#' && qs[0] != '\0')
+    {
+        if ( qs_strncmp(key, qs, key_len) == 0 )
+            break;
+        qs += strcspn(qs, "&") + 1;
+    }
+
+    if ( qs[0] == '\0' ) return NULL;
+
+    qs += strcspn(qs, "=&#");
+    if ( qs[0] == '=' )
+    {
+        qs++;
+        i = strcspn(qs, "&=#");
+        strncpy(val, qs, (val_len-1)<(i+1) ? (val_len-1) : (i+1));
+        qs_decode(val);
+    }
+    else
+    {
+        if ( val_len > 0 )
+            val[0] = '\0';
+    }
+
+    return val;
+}
+// ----------------------------------------------------------------------------
+
+
+namespace crow 
+{
+    class query_string
+    {
+    public:
+        static const int MAX_KEY_VALUE_PAIRS_COUNT = 256;
+
+        query_string()
+        {
+
+        }
+
+        query_string(const query_string& qs)
+            : url_(qs.url_)
+        {
+            for(auto p:qs.key_value_pairs_)
+            {
+                key_value_pairs_.push_back((char*)(p-qs.url_.c_str()+url_.c_str()));
+            }
+        }
+
+        query_string& operator = (const query_string& qs)
+        {
+            url_ = qs.url_;
+            key_value_pairs_.clear();
+            for(auto p:qs.key_value_pairs_)
+            {
+                key_value_pairs_.push_back((char*)(p-qs.url_.c_str()+url_.c_str()));
+            }
+            return *this;
+        }
+
+        query_string& operator = (query_string&& qs)
+        {
+            key_value_pairs_ = std::move(qs.key_value_pairs_);
+            char* old_data = (char*)qs.url_.c_str();
+            url_ = std::move(qs.url_);
+            for(auto& p:key_value_pairs_)
+            {
+                p += (char*)url_.c_str() - old_data;
+            }
+            return *this;
+        }
+
+
+        query_string(std::string url)
+            : url_(std::move(url))
+        {
+            if (url_.empty())
+                return;
+
+            key_value_pairs_.resize(MAX_KEY_VALUE_PAIRS_COUNT);
+
+            int count = qs_parse(&url_[0], &key_value_pairs_[0], MAX_KEY_VALUE_PAIRS_COUNT);
+            key_value_pairs_.resize(count);
+        }
+
+        void clear() 
+        {
+            key_value_pairs_.clear();
+            url_.clear();
+        }
+
+        friend std::ostream& operator<<(std::ostream& os, const query_string& qs)
+        {
+            os << "[ ";
+            for(size_t i = 0; i < qs.key_value_pairs_.size(); ++i) {
+                if (i)
+                    os << ", ";
+                os << qs.key_value_pairs_[i];
+            }
+            os << " ]";
+            return os;
+
+        }
+
+        char* get (const std::string& name) const
+        {
+            char* ret = qs_k2v(name.c_str(), key_value_pairs_.data(), key_value_pairs_.size());
+            return ret;
+        }
+
+        std::vector<char*> get_list (const std::string& name) const
+        {
+            std::vector<char*> ret;
+            std::string plus = name + "[]";            
+            char* element = nullptr;
+
+            int count = 0;
+            while(1)
+            {
+                element = qs_k2v(plus.c_str(), key_value_pairs_.data(), key_value_pairs_.size(), count++);
+                if (!element)
+                    break;
+                ret.push_back(element);
+            }
+            return ret;
+        }
+
+
+    private:
+        std::string url_;
+        std::vector<char*> key_value_pairs_;
+    };
+
+} // end namespace

ext/crow/routing.h

@@ -0,0 +1,892 @@
+#pragma once
+
+#include <cstdint>
+#include <utility>
+#include <tuple>
+#include <unordered_map>
+#include <memory>
+#include <boost/lexical_cast.hpp>
+#include <vector>
+
+#include "common.h"
+#include "http_response.h"
+#include "http_request.h"
+#include "utility.h"
+#include "logging.h"
+
+namespace crow
+{
+    class BaseRule
+    {
+    public:
+        BaseRule(std::string rule)
+            : rule_(std::move(rule))
+        {
+        }
+
+        virtual ~BaseRule()
+        {
+        }
+        
+        virtual void validate() = 0;
+
+        virtual void handle(const request&, response&, const routing_params&) = 0;
+
+        uint32_t get_methods()
+        {
+            return methods_;
+        }
+
+    protected:
+        uint32_t methods_{1<<(int)HTTPMethod::GET};
+
+        std::string rule_;
+        std::string name_;
+        friend class Router;
+        template <typename T>
+        friend struct RuleParameterTraits;
+    };
+
+
+    namespace detail
+    {
+        namespace routing_handler_call_helper
+        {
+            template <typename T, int Pos>
+            struct call_pair
+            {
+                using type = T;
+                static const int pos = Pos;
+            };
+
+            template <typename H1>
+            struct call_params
+            {
+                H1& handler;
+                const routing_params& params;
+                const request& req;
+                response& res;
+            };
+
+            template <typename F, int NInt, int NUint, int NDouble, int NString, typename S1, typename S2> 
+            struct call
+            {
+            };
+
+            template <typename F, int NInt, int NUint, int NDouble, int NString, typename ... Args1, typename ... Args2> 
+            struct call<F, NInt, NUint, NDouble, NString, black_magic::S<int64_t, Args1...>, black_magic::S<Args2...>>
+            {
+                void operator()(F cparams)
+                {
+                    using pushed = typename black_magic::S<Args2...>::template push_back<call_pair<int64_t, NInt>>;
+                    call<F, NInt+1, NUint, NDouble, NString,
+                        black_magic::S<Args1...>, pushed>()(cparams);
+                }
+            };
+
+            template <typename F, int NInt, int NUint, int NDouble, int NString, typename ... Args1, typename ... Args2> 
+            struct call<F, NInt, NUint, NDouble, NString, black_magic::S<uint64_t, Args1...>, black_magic::S<Args2...>>
+            {
+                void operator()(F cparams)
+                {
+                    using pushed = typename black_magic::S<Args2...>::template push_back<call_pair<uint64_t, NUint>>;
+                    call<F, NInt, NUint+1, NDouble, NString,
+                        black_magic::S<Args1...>, pushed>()(cparams);
+                }
+            };
+
+            template <typename F, int NInt, int NUint, int NDouble, int NString, typename ... Args1, typename ... Args2> 
+            struct call<F, NInt, NUint, NDouble, NString, black_magic::S<double, Args1...>, black_magic::S<Args2...>>
+            {
+                void operator()(F cparams)
+                {
+                    using pushed = typename black_magic::S<Args2...>::template push_back<call_pair<double, NDouble>>;
+                    call<F, NInt, NUint, NDouble+1, NString,
+                        black_magic::S<Args1...>, pushed>()(cparams);
+                }
+            };
+
+            template <typename F, int NInt, int NUint, int NDouble, int NString, typename ... Args1, typename ... Args2> 
+            struct call<F, NInt, NUint, NDouble, NString, black_magic::S<std::string, Args1...>, black_magic::S<Args2...>>
+            {
+                void operator()(F cparams)
+                {
+                    using pushed = typename black_magic::S<Args2...>::template push_back<call_pair<std::string, NString>>;
+                    call<F, NInt, NUint, NDouble, NString+1,
+                        black_magic::S<Args1...>, pushed>()(cparams);
+                }
+            };
+
+            template <typename F, int NInt, int NUint, int NDouble, int NString, typename ... Args1> 
+            struct call<F, NInt, NUint, NDouble, NString, black_magic::S<>, black_magic::S<Args1...>>
+            {
+                void operator()(F cparams)
+                {
+                    cparams.handler(
+                        cparams.req,
+                        cparams.res,
+                        cparams.params.template get<typename Args1::type>(Args1::pos)... 
+                    );
+                }
+            };
+
+            template <typename Func, typename ... ArgsWrapped>
+            struct Wrapped
+            {
+                template <typename ... Args>
+                void set(Func f, typename std::enable_if<
+                    !std::is_same<typename std::tuple_element<0, std::tuple<Args..., void>>::type, const request&>::value
+                , int>::type = 0)
+                {
+                    handler_ = (
+#ifdef CROW_CAN_USE_CPP14
+                        [f = std::move(f)]
+#else
+                        [f]
+#endif
+                        (const request&, response& res, Args... args){
+                            res = response(f(args...));
+                            res.end();
+                        });
+                }
+
+                template <typename Req, typename ... Args>
+                struct req_handler_wrapper
+                {
+                    req_handler_wrapper(Func f)
+                        : f(std::move(f))
+                    {
+                    }
+
+                    void operator()(const request& req, response& res, Args... args)
+                    {
+                        res = response(f(req, args...));
+                        res.end();
+                    }
+
+                    Func f;
+                };
+
+                template <typename ... Args>
+                void set(Func f, typename std::enable_if<
+                        std::is_same<typename std::tuple_element<0, std::tuple<Args..., void>>::type, const request&>::value &&
+                        !std::is_same<typename std::tuple_element<1, std::tuple<Args..., void, void>>::type, response&>::value
+                        , int>::type = 0)
+                {
+                    handler_ = req_handler_wrapper<Args...>(std::move(f));
+                    /*handler_ = (
+                        [f = std::move(f)]
+                        (const request& req, response& res, Args... args){
+                             res = response(f(req, args...));
+                             res.end();
+                        });*/
+                }
+
+                template <typename ... Args>
+                void set(Func f, typename std::enable_if<
+                        std::is_same<typename std::tuple_element<0, std::tuple<Args..., void>>::type, const request&>::value &&
+                        std::is_same<typename std::tuple_element<1, std::tuple<Args..., void, void>>::type, response&>::value
+                        , int>::type = 0)
+                {
+                    handler_ = std::move(f);
+                }
+
+                template <typename ... Args>
+                struct handler_type_helper
+                {
+                    using type = std::function<void(const crow::request&, crow::response&, Args...)>;
+                    using args_type = black_magic::S<typename black_magic::promote_t<Args>...>; 
+                };
+
+                template <typename ... Args>
+                struct handler_type_helper<const request&, Args...>
+                {
+                    using type = std::function<void(const crow::request&, crow::response&, Args...)>;
+                    using args_type = black_magic::S<typename black_magic::promote_t<Args>...>; 
+                };
+
+                template <typename ... Args>
+                struct handler_type_helper<const request&, response&, Args...>
+                {
+                    using type = std::function<void(const crow::request&, crow::response&, Args...)>;
+                    using args_type = black_magic::S<typename black_magic::promote_t<Args>...>; 
+                };
+
+                typename handler_type_helper<ArgsWrapped...>::type handler_;
+
+                void operator()(const request& req, response& res, const routing_params& params)
+                {
+                    detail::routing_handler_call_helper::call<
+                        detail::routing_handler_call_helper::call_params<
+                            decltype(handler_)>,
+                        0, 0, 0, 0, 
+                        typename handler_type_helper<ArgsWrapped...>::args_type,
+                        black_magic::S<>
+                    >()(
+                        detail::routing_handler_call_helper::call_params<
+                            decltype(handler_)>
+                        {handler_, params, req, res}
+                   );
+                }
+            };
+
+        }
+    }
+
+    template <typename T>
+    struct RuleParameterTraits
+    {
+        using self_t = T;
+        self_t& name(std::string name) noexcept
+        {
+            ((self_t*)this)->name_ = std::move(name);
+            return (self_t&)*this;
+        }
+
+        self_t& methods(HTTPMethod method)
+        {
+            ((self_t*)this)->methods_ = 1 << (int)method;
+            return (self_t&)*this;
+        }
+
+        template <typename ... MethodArgs>
+        self_t& methods(HTTPMethod method, MethodArgs ... args_method)
+        {
+            methods(args_method...);
+            ((self_t*)this)->methods_ |= 1 << (int)method;
+            return (self_t&)*this;
+        }
+    };
+
+    class DynamicRule : public BaseRule, public RuleParameterTraits<DynamicRule>
+    {
+    public:
+
+        DynamicRule(std::string rule)
+            : BaseRule(std::move(rule))
+        {
+        }
+
+        void validate() override
+        {
+            if (!erased_handler_)
+            {
+                throw std::runtime_error(name_ + (!name_.empty() ? ": " : "") + "no handler for url " + rule_);
+            }
+        }
+
+        void handle(const request& req, response& res, const routing_params& params) override
+        {
+            erased_handler_(req, res, params);
+        }
+
+        template <typename Func>
+        void operator()(Func f)
+        {
+#ifdef CROW_MSVC_WORKAROUND
+            using function_t = utility::function_traits<decltype(&Func::operator())>;
+#else
+            using function_t = utility::function_traits<Func>;
+#endif
+            erased_handler_ = wrap(std::move(f), black_magic::gen_seq<function_t::arity>());
+        }
+
+        // enable_if Arg1 == request && Arg2 == response
+        // enable_if Arg1 == request && Arg2 != resposne
+        // enable_if Arg1 != request
+#ifdef CROW_MSVC_WORKAROUND
+        template <typename Func, size_t ... Indices>
+#else
+        template <typename Func, unsigned ... Indices>
+#endif
+        std::function<void(const request&, response&, const routing_params&)> 
+        wrap(Func f, black_magic::seq<Indices...>)
+        {
+#ifdef CROW_MSVC_WORKAROUND
+            using function_t = utility::function_traits<decltype(&Func::operator())>;
+#else
+            using function_t = utility::function_traits<Func>;
+#endif
+            if (!black_magic::is_parameter_tag_compatible(
+                black_magic::get_parameter_tag_runtime(rule_.c_str()), 
+                black_magic::compute_parameter_tag_from_args_list<
+                    typename function_t::template arg<Indices>...>::value))
+            {
+                throw std::runtime_error("route_dynamic: Handler type is mismatched with URL parameters: " + rule_);
+            }
+            auto ret = detail::routing_handler_call_helper::Wrapped<Func, typename function_t::template arg<Indices>...>();
+            ret.template set<
+                typename function_t::template arg<Indices>...
+            >(std::move(f));
+            return ret;
+        }
+
+        template <typename Func>
+        void operator()(std::string name, Func&& f)
+        {
+            name_ = std::move(name);
+            (*this).template operator()<Func>(std::forward(f));
+        }
+    private:
+        std::function<void(const request&, response&, const routing_params&)> erased_handler_;
+
+    };
+
+    template <typename ... Args>
+    class TaggedRule : public BaseRule, public RuleParameterTraits<TaggedRule<Args...>>
+    {
+    public:
+        using self_t = TaggedRule<Args...>;
+
+        TaggedRule(std::string rule)
+            : BaseRule(std::move(rule))
+        {
+        }
+
+        void validate()
+        {
+            if (!handler_)
+            {
+                throw std::runtime_error(name_ + (!name_.empty() ? ": " : "") + "no handler for url " + rule_);
+            }
+        }
+
+        template <typename Func>
+        typename std::enable_if<black_magic::CallHelper<Func, black_magic::S<Args...>>::value, void>::type
+        operator()(Func&& f)
+        {
+            static_assert(black_magic::CallHelper<Func, black_magic::S<Args...>>::value ||
+                black_magic::CallHelper<Func, black_magic::S<crow::request, Args...>>::value , 
+                "Handler type is mismatched with URL parameters");
+            static_assert(!std::is_same<void, decltype(f(std::declval<Args>()...))>::value, 
+                "Handler function cannot have void return type; valid return types: string, int, crow::resposne, crow::json::wvalue");
+
+                handler_ = [f = std::move(f)](const request&, response& res, Args ... args){
+                    res = response(f(args...));
+                    res.end();
+                };
+        }
+
+        template <typename Func>
+        typename std::enable_if<
+            !black_magic::CallHelper<Func, black_magic::S<Args...>>::value &&
+            black_magic::CallHelper<Func, black_magic::S<crow::request, Args...>>::value, 
+            void>::type
+        operator()(Func&& f)
+        {
+            static_assert(black_magic::CallHelper<Func, black_magic::S<Args...>>::value ||
+                black_magic::CallHelper<Func, black_magic::S<crow::request, Args...>>::value, 
+                "Handler type is mismatched with URL parameters");
+            static_assert(!std::is_same<void, decltype(f(std::declval<crow::request>(), std::declval<Args>()...))>::value, 
+                "Handler function cannot have void return type; valid return types: string, int, crow::resposne, crow::json::wvalue");
+
+                handler_ = [f = std::move(f)](const crow::request& req, crow::response& res, Args ... args){
+                    res = response(f(req, args...));
+                    res.end();
+                };
+        }
+
+        template <typename Func>
+        typename std::enable_if<
+            !black_magic::CallHelper<Func, black_magic::S<Args...>>::value &&
+            !black_magic::CallHelper<Func, black_magic::S<crow::request, Args...>>::value, 
+            void>::type
+        operator()(Func&& f)
+        {
+            static_assert(black_magic::CallHelper<Func, black_magic::S<Args...>>::value ||
+                black_magic::CallHelper<Func, black_magic::S<crow::request, Args...>>::value ||
+                black_magic::CallHelper<Func, black_magic::S<crow::request, crow::response&, Args...>>::value
+                , 
+                "Handler type is mismatched with URL parameters");
+            static_assert(std::is_same<void, decltype(f(std::declval<crow::request>(), std::declval<crow::response&>(), std::declval<Args>()...))>::value, 
+                "Handler function with response argument should have void return type");
+
+                handler_ = std::move(f);
+        }
+
+        template <typename Func>
+        void operator()(std::string name, Func&& f)
+        {
+            name_ = std::move(name);
+            (*this).template operator()<Func>(std::forward(f));
+        }
+
+        void handle(const request& req, response& res, const routing_params& params) override
+        {
+            detail::routing_handler_call_helper::call<
+                detail::routing_handler_call_helper::call_params<
+                    decltype(handler_)>, 
+                0, 0, 0, 0, 
+                black_magic::S<Args...>, 
+                black_magic::S<>
+            >()(
+                detail::routing_handler_call_helper::call_params<
+                    decltype(handler_)>
+                {handler_, params, req, res}
+            );
+        }
+
+    private:
+        std::function<void(const crow::request&, crow::response&, Args...)> handler_;
+
+    };
+
+    const int RULE_SPECIAL_REDIRECT_SLASH = 1;
+
+    class Trie
+    {
+    public:
+        struct Node
+        {
+            unsigned rule_index{};
+            std::array<unsigned, (int)ParamType::MAX> param_childrens{};
+            std::unordered_map<std::string, unsigned> children;
+
+            bool IsSimpleNode() const
+            {
+                return 
+                    !rule_index &&
+                    std::all_of(
+                        std::begin(param_childrens), 
+                        std::end(param_childrens), 
+                        [](unsigned x){ return !x; });
+            }
+        };
+
+        Trie() : nodes_(1)
+        {
+        }
+
+private:
+        void optimizeNode(Node* node)
+        {
+            for(auto x : node->param_childrens)
+            {
+                if (!x)
+                    continue;
+                Node* child = &nodes_[x];
+                optimizeNode(child);
+            }
+            if (node->children.empty())
+                return;
+            bool mergeWithChild = true;
+            for(auto& kv : node->children)
+            {
+                Node* child = &nodes_[kv.second];
+                if (!child->IsSimpleNode())
+                {
+                    mergeWithChild = false;
+                    break;
+                }
+            }
+            if (mergeWithChild)
+            {
+                decltype(node->children) merged;
+                for(auto& kv : node->children)
+                {
+                    Node* child = &nodes_[kv.second];
+                    for(auto& child_kv : child->children)
+                    {
+                        merged[kv.first + child_kv.first] = child_kv.second;
+                    }
+                }
+                node->children = std::move(merged);
+                optimizeNode(node);
+            }
+            else
+            {
+                for(auto& kv : node->children)
+                {
+                    Node* child = &nodes_[kv.second];
+                    optimizeNode(child);
+                }
+            }
+        }
+
+        void optimize()
+        {
+            optimizeNode(head());
+        }
+
+public:
+        void validate()
+        {
+            if (!head()->IsSimpleNode())
+                throw std::runtime_error("Internal error: Trie header should be simple!");
+            optimize();
+        }
+
+        std::pair<unsigned, routing_params> find(const std::string& req_url, const Node* node = nullptr, unsigned pos = 0, routing_params* params = nullptr) const
+        {
+            routing_params empty;
+            if (params == nullptr)
+                params = &empty;
+
+            unsigned found{};
+            routing_params match_params;
+
+            if (node == nullptr)
+                node = head();
+            if (pos == req_url.size())
+                return {node->rule_index, *params};
+
+            auto update_found = [&found, &match_params](std::pair<unsigned, routing_params>& ret)
+            {
+                if (ret.first && (!found || found > ret.first))
+                {
+                    found = ret.first;
+                    match_params = std::move(ret.second);
+                }
+            };
+
+            if (node->param_childrens[(int)ParamType::INT])
+            {
+                char c = req_url[pos];
+                if ((c >= '0' && c <= '9') || c == '+' || c == '-')
+                {
+                    char* eptr;
+                    errno = 0;
+                    long long int value = strtoll(req_url.data()+pos, &eptr, 10);
+                    if (errno != ERANGE && eptr != req_url.data()+pos)
+                    {
+                        params->int_params.push_back(value);
+                        auto ret = find(req_url, &nodes_[node->param_childrens[(int)ParamType::INT]], eptr - req_url.data(), params);
+                        update_found(ret);
+                        params->int_params.pop_back();
+                    }
+                }
+            }
+
+            if (node->param_childrens[(int)ParamType::UINT])
+            {
+                char c = req_url[pos];
+                if ((c >= '0' && c <= '9') || c == '+')
+                {
+                    char* eptr;
+                    errno = 0;
+                    unsigned long long int value = strtoull(req_url.data()+pos, &eptr, 10);
+                    if (errno != ERANGE && eptr != req_url.data()+pos)
+                    {
+                        params->uint_params.push_back(value);
+                        auto ret = find(req_url, &nodes_[node->param_childrens[(int)ParamType::UINT]], eptr - req_url.data(), params);
+                        update_found(ret);
+                        params->uint_params.pop_back();
+                    }
+                }
+            }
+
+            if (node->param_childrens[(int)ParamType::DOUBLE])
+            {
+                char c = req_url[pos];
+                if ((c >= '0' && c <= '9') || c == '+' || c == '-' || c == '.')
+                {
+                    char* eptr;
+                    errno = 0;
+                    double value = strtod(req_url.data()+pos, &eptr);
+                    if (errno != ERANGE && eptr != req_url.data()+pos)
+                    {
+                        params->double_params.push_back(value);
+                        auto ret = find(req_url, &nodes_[node->param_childrens[(int)ParamType::DOUBLE]], eptr - req_url.data(), params);
+                        update_found(ret);
+                        params->double_params.pop_back();
+                    }
+                }
+            }
+
+            if (node->param_childrens[(int)ParamType::STRING])
+            {
+                size_t epos = pos;
+                for(; epos < req_url.size(); epos ++)
+                {
+                    if (req_url[epos] == '/')
+                        break;
+                }
+
+                if (epos != pos)
+                {
+                    params->string_params.push_back(req_url.substr(pos, epos-pos));
+                    auto ret = find(req_url, &nodes_[node->param_childrens[(int)ParamType::STRING]], epos, params);
+                    update_found(ret);
+                    params->string_params.pop_back();
+                }
+            }
+
+            if (node->param_childrens[(int)ParamType::PATH])
+            {
+                size_t epos = req_url.size();
+
+                if (epos != pos)
+                {
+                    params->string_params.push_back(req_url.substr(pos, epos-pos));
+                    auto ret = find(req_url, &nodes_[node->param_childrens[(int)ParamType::PATH]], epos, params);
+                    update_found(ret);
+                    params->string_params.pop_back();
+                }
+            }
+
+            for(auto& kv : node->children)
+            {
+                const std::string& fragment = kv.first;
+                const Node* child = &nodes_[kv.second];
+
+                if (req_url.compare(pos, fragment.size(), fragment) == 0)
+                {
+                    auto ret = find(req_url, child, pos + fragment.size(), params);
+                    update_found(ret);
+                }
+            }
+
+            return {found, match_params};
+        }
+
+        void add(const std::string& url, unsigned rule_index)
+        {
+            unsigned idx{0};
+
+            for(unsigned i = 0; i < url.size(); i ++)
+            {
+                char c = url[i];
+                if (c == '<')
+                {
+                    static struct ParamTraits
+                    {
+                        ParamType type;
+                        std::string name;
+                    } paramTraits[] =
+                    {
+                        { ParamType::INT, "<int>" },
+                        { ParamType::UINT, "<uint>" },
+                        { ParamType::DOUBLE, "<float>" },
+                        { ParamType::DOUBLE, "<double>" },
+                        { ParamType::STRING, "<str>" },
+                        { ParamType::STRING, "<string>" },
+                        { ParamType::PATH, "<path>" },
+                    };
+
+                    for(auto& x:paramTraits)
+                    {
+                        if (url.compare(i, x.name.size(), x.name) == 0)
+                        {
+                            if (!nodes_[idx].param_childrens[(int)x.type])
+                            {
+                                auto new_node_idx = new_node();
+                                nodes_[idx].param_childrens[(int)x.type] = new_node_idx;
+                            }
+                            idx = nodes_[idx].param_childrens[(int)x.type];
+                            i += x.name.size();
+                            break;
+                        }
+                    }
+
+                    i --;
+                }
+                else
+                {
+                    std::string piece(&c, 1);
+                    if (!nodes_[idx].children.count(piece))
+                    {
+                        auto new_node_idx = new_node();
+                        nodes_[idx].children.emplace(piece, new_node_idx);
+                    }
+                    idx = nodes_[idx].children[piece];
+                }
+            }
+            if (nodes_[idx].rule_index)
+                throw std::runtime_error("handler already exists for " + url);
+            nodes_[idx].rule_index = rule_index;
+        }
+    private:
+        void debug_node_print(Node* n, int level)
+        {
+            for(int i = 0; i < (int)ParamType::MAX; i ++)
+            {
+                if (n->param_childrens[i])
+                {
+                    CROW_LOG_DEBUG << std::string(2*level, ' ') /*<< "("<<n->param_childrens[i]<<") "*/;
+                    switch((ParamType)i)
+                    {
+                        case ParamType::INT:
+                            CROW_LOG_DEBUG << "<int>";
+                            break;
+                        case ParamType::UINT:
+                            CROW_LOG_DEBUG << "<uint>";
+                            break;
+                        case ParamType::DOUBLE:
+                            CROW_LOG_DEBUG << "<float>";
+                            break;
+                        case ParamType::STRING:
+                            CROW_LOG_DEBUG << "<str>";
+                            break;
+                        case ParamType::PATH:
+                            CROW_LOG_DEBUG << "<path>";
+                            break;
+                        default:
+                            CROW_LOG_DEBUG << "<ERROR>";
+                            break;
+                    }
+
+                    debug_node_print(&nodes_[n->param_childrens[i]], level+1);
+                }
+            }
+            for(auto& kv : n->children)
+            {
+                CROW_LOG_DEBUG << std::string(2*level, ' ') /*<< "(" << kv.second << ") "*/ << kv.first;
+                debug_node_print(&nodes_[kv.second], level+1);
+            }
+        }
+
+    public:
+        void debug_print()
+        {
+            debug_node_print(head(), 0);
+        }
+
+    private:
+        const Node* head() const
+        {
+            return &nodes_.front();
+        }
+
+        Node* head()
+        {
+            return &nodes_.front();
+        }
+
+        unsigned new_node()
+        {
+            nodes_.resize(nodes_.size()+1);
+            return nodes_.size() - 1;
+        }
+
+        std::vector<Node> nodes_;
+    };
+
+    class Router
+    {
+    public:
+        Router() : rules_(2) 
+        {
+        }
+
+        DynamicRule& new_rule_dynamic(const std::string& rule)
+        {
+            auto ruleObject = new DynamicRule(rule);
+
+            internal_add_rule_object(rule, ruleObject);
+
+            return *ruleObject;
+        }
+
+        template <uint64_t N>
+        typename black_magic::arguments<N>::type::template rebind<TaggedRule>& new_rule_tagged(const std::string& rule)
+        {
+            using RuleT = typename black_magic::arguments<N>::type::template rebind<TaggedRule>;
+            auto ruleObject = new RuleT(rule);
+
+            internal_add_rule_object(rule, ruleObject);
+
+            return *ruleObject;
+        }
+
+        void internal_add_rule_object(const std::string& rule, BaseRule* ruleObject)
+        {
+            rules_.emplace_back(ruleObject);
+            trie_.add(rule, rules_.size() - 1);
+
+            // directory case: 
+            //   request to `/about' url matches `/about/' rule 
+            if (rule.size() > 1 && rule.back() == '/')
+            {
+                std::string rule_without_trailing_slash = rule;
+                rule_without_trailing_slash.pop_back();
+                trie_.add(rule_without_trailing_slash, RULE_SPECIAL_REDIRECT_SLASH);
+            }
+        }
+
+        void validate()
+        {
+            trie_.validate();
+            for(auto& rule:rules_)
+            {
+                if (rule)
+                    rule->validate();
+            }
+        }
+
+        void handle(const request& req, response& res)
+        {
+            auto found = trie_.find(req.url);
+
+            unsigned rule_index = found.first;
+            CROW_LOG_DEBUG << "???" << rule_index;
+
+            if (!rule_index)
+            {
+                CROW_LOG_DEBUG << "Cannot match rules " << req.url;
+                res = response(404);
+                res.end();
+                return;
+            }
+
+            if (rule_index >= rules_.size())
+                throw std::runtime_error("Trie internal structure corrupted!");
+
+            if (rule_index == RULE_SPECIAL_REDIRECT_SLASH)
+            {
+                CROW_LOG_INFO << "Redirecting to a url with trailing slash: " << req.url;
+                res = response(301);
+
+                // TODO absolute url building
+                if (req.get_header_value("Host").empty())
+                {
+                    res.add_header("Location", req.url + "/");
+                }
+                else
+                {
+                    res.add_header("Location", "http://" + req.get_header_value("Host") + req.url + "/");
+                }
+                res.end();
+                return;
+            }
+
+            if ((rules_[rule_index]->get_methods() & (1<<(uint32_t)req.method)) == 0)
+            {
+                CROW_LOG_DEBUG << "Rule found but method mismatch: " << req.url << " with " << method_name(req.method) << "(" << (uint32_t)req.method << ") / " << rules_[rule_index]->get_methods();
+                res = response(404);
+                res.end();
+                return;
+            }
+
+            CROW_LOG_DEBUG << "Matched rule '" << rules_[rule_index]->rule_ << "' " << (uint32_t)req.method << " / " << rules_[rule_index]->get_methods();
+
+            // any uncaught exceptions become 500s
+            try
+            {
+                rules_[rule_index]->handle(req, res, found.second);
+            }
+            catch(std::exception& e)
+            {
+                CROW_LOG_ERROR << "An uncaught exception occurred: " << e.what();
+                res = response(500);
+                res.end();
+                return;   
+            }
+            catch(...)
+            {
+                CROW_LOG_ERROR << "An uncaught exception occurred. The type was unknown so no information was available.";
+                res = response(500);
+                res.end();
+                return;   
+            }
+        }
+
+        void debug_print()
+        {
+            trie_.debug_print();
+        }
+
+    private:
+        std::vector<std::unique_ptr<BaseRule>> rules_;
+        Trie trie_;
+    };
+}

ext/crow/settings.h

@@ -0,0 +1,38 @@
+#pragma once
+// settings for crow
+// TODO - replace with runtime config. libucl?
+
+/* #ifdef - enables debug mode */
+#define CROW_ENABLE_DEBUG
+
+/* #ifdef - enables logging */
+#define CROW_ENABLE_LOGGING
+
+/* #ifdef - enables SSL */
+//#define CROW_ENABLE_SSL
+
+/* #define - specifies log level */
+/*
+    DEBUG       = 0
+    INFO        = 1
+    WARNING     = 2
+    ERROR       = 3
+    CRITICAL    = 4
+
+    default to INFO
+*/
+#define CROW_LOG_LEVEL 1
+
+
+// compiler flags
+#if __cplusplus >= 201402L
+#define CROW_CAN_USE_CPP14
+#endif
+
+#if defined(_MSC_VER)
+#if _MSC_VER < 1900
+#define CROW_MSVC_WORKAROUND
+#define constexpr const
+#define noexcept throw()
+#endif
+#endif

ext/crow/socket_adaptors.h

@@ -0,0 +1,98 @@
+#pragma once
+#include <boost/asio.hpp>
+#include "settings.h"
+namespace crow
+{
+    using namespace boost;
+    using tcp = asio::ip::tcp;
+
+    struct SocketAdaptor
+    {
+        using context = void;
+        SocketAdaptor(boost::asio::io_service& io_service, context*)
+            : socket_(io_service)
+        {
+        }
+
+        tcp::socket& raw_socket()
+        {
+            return socket_;
+        }
+
+        tcp::socket& socket()
+        {
+            return socket_;
+        }
+
+        tcp::endpoint remote_endpoint()
+        {
+            return socket_.remote_endpoint();
+        }
+
+        bool is_open()
+        {
+            return socket_.is_open();
+        }
+
+        void close()
+        {
+            socket_.close();
+        }
+
+        template <typename F> 
+        void start(F f)
+        {
+            f(boost::system::error_code());
+        }
+
+        tcp::socket socket_;
+    };
+
+#ifdef CROW_ENABLE_SSL
+    struct SSLAdaptor
+    {
+        using context = boost::asio::ssl::context;
+        SSLAdaptor(boost::asio::io_service& io_service, context* ctx)
+            : ssl_socket_(io_service, *ctx)
+        {
+        }
+
+        boost::asio::ssl::stream<tcp::socket>& socket()
+        {
+            return ssl_socket_;
+        }
+
+        tcp::socket::lowest_layer_type&
+        raw_socket()
+        {
+            return ssl_socket_.lowest_layer();
+        }
+
+        tcp::endpoint remote_endpoint()
+        {
+            return raw_socket().remote_endpoint();
+        }
+
+        bool is_open()
+        {
+            return raw_socket().is_open();
+        }
+
+        void close()
+        {
+            raw_socket().close();
+        }
+
+        template <typename F> 
+        void start(F f)
+        {
+            ssl_socket_.async_handshake(boost::asio::ssl::stream_base::server,
+                    [f](const boost::system::error_code& ec) {
+                        f(ec);
+                    });
+        }
+
+        boost::asio::ssl::stream<tcp::socket> ssl_socket_;
+    };
+#endif
+}

ext/crow/utility.h

@@ -0,0 +1,503 @@
+#pragma once
+
+#include <cstdint>
+#include <stdexcept>
+#include <tuple>
+#include <type_traits>
+#include <cstring>
+#include <functional>
+
+namespace crow
+{
+    namespace black_magic
+    {
+#ifndef CROW_MSVC_WORKAROUND
+        struct OutOfRange
+        {
+            OutOfRange(unsigned pos, unsigned length) {}
+        };
+        constexpr unsigned requires_in_range( unsigned i, unsigned len )
+        {
+            return i >= len ? throw OutOfRange(i, len) : i;
+        }
+
+        class const_str
+        {
+            const char * const begin_;
+            unsigned size_;
+
+            public:
+            template< unsigned N >
+                constexpr const_str( const char(&arr)[N] ) : begin_(arr), size_(N - 1) {
+                    static_assert( N >= 1, "not a string literal");
+                }
+            constexpr char operator[]( unsigned i ) const { 
+                return requires_in_range(i, size_), begin_[i]; 
+            }
+
+            constexpr operator const char *() const { 
+                return begin_; 
+            }
+
+            constexpr const char* begin() const { return begin_; }
+            constexpr const char* end() const { return begin_ + size_; }
+
+            constexpr unsigned size() const { 
+                return size_; 
+            }
+        };
+
+        constexpr unsigned find_closing_tag(const_str s, unsigned p)
+        {
+            return s[p] == '>' ? p : find_closing_tag(s, p+1);
+        }
+
+        constexpr bool is_valid(const_str s, unsigned i = 0, int f = 0)
+        {
+            return 
+                i == s.size()
+                    ? f == 0 :
+                f < 0 || f >= 2
+                    ? false :
+                s[i] == '<'
+                    ? is_valid(s, i+1, f+1) :
+                s[i] == '>'
+                    ? is_valid(s, i+1, f-1) :
+                is_valid(s, i+1, f);
+        }
+
+        constexpr bool is_equ_p(const char* a, const char* b, unsigned n)
+        {
+            return
+                *a == 0 && *b == 0 && n == 0 
+                    ? true :
+                (*a == 0 || *b == 0)
+                    ? false :
+                n == 0
+                    ? true :
+                *a != *b
+                    ? false :
+                is_equ_p(a+1, b+1, n-1);
+        }
+
+        constexpr bool is_equ_n(const_str a, unsigned ai, const_str b, unsigned bi, unsigned n)
+        {
+            return 
+                ai + n > a.size() || bi + n > b.size() 
+                    ? false :
+                n == 0 
+                    ? true : 
+                a[ai] != b[bi] 
+                    ? false : 
+                is_equ_n(a,ai+1,b,bi+1,n-1);
+        }
+
+        constexpr bool is_int(const_str s, unsigned i)
+        {
+            return is_equ_n(s, i, "<int>", 0, 5);
+        }
+
+        constexpr bool is_uint(const_str s, unsigned i)
+        {
+            return is_equ_n(s, i, "<uint>", 0, 6);
+        }
+
+        constexpr bool is_float(const_str s, unsigned i)
+        {
+            return is_equ_n(s, i, "<float>", 0, 7) ||
+                is_equ_n(s, i, "<double>", 0, 8);
+        }
+
+        constexpr bool is_str(const_str s, unsigned i)
+        {
+            return is_equ_n(s, i, "<str>", 0, 5) ||
+                is_equ_n(s, i, "<string>", 0, 8);
+        }
+
+        constexpr bool is_path(const_str s, unsigned i)
+        {
+            return is_equ_n(s, i, "<path>", 0, 6);
+        }
+#endif
+        template <typename T> 
+        struct parameter_tag
+        {
+            static const int value = 0;
+        };
+#define CROW_INTERNAL_PARAMETER_TAG(t, i) \
+template <> \
+struct parameter_tag<t> \
+{ \
+    static const int value = i; \
+};
+        CROW_INTERNAL_PARAMETER_TAG(int, 1);
+        CROW_INTERNAL_PARAMETER_TAG(char, 1);
+        CROW_INTERNAL_PARAMETER_TAG(short, 1);
+        CROW_INTERNAL_PARAMETER_TAG(long, 1);
+        CROW_INTERNAL_PARAMETER_TAG(long long, 1);
+        CROW_INTERNAL_PARAMETER_TAG(unsigned int, 2);
+        CROW_INTERNAL_PARAMETER_TAG(unsigned char, 2);
+        CROW_INTERNAL_PARAMETER_TAG(unsigned short, 2);
+        CROW_INTERNAL_PARAMETER_TAG(unsigned long, 2);
+        CROW_INTERNAL_PARAMETER_TAG(unsigned long long, 2);
+        CROW_INTERNAL_PARAMETER_TAG(double, 3);
+        CROW_INTERNAL_PARAMETER_TAG(std::string, 4);
+#undef CROW_INTERNAL_PARAMETER_TAG
+        template <typename ... Args>
+        struct compute_parameter_tag_from_args_list;
+
+        template <>
+        struct compute_parameter_tag_from_args_list<>
+        {
+            static const int value = 0;
+        };
+
+        template <typename Arg, typename ... Args>
+        struct compute_parameter_tag_from_args_list<Arg, Args...>
+        {
+            static const int sub_value = 
+                compute_parameter_tag_from_args_list<Args...>::value;
+            static const int value = 
+                parameter_tag<typename std::decay<Arg>::type>::value
+                ? sub_value* 6 + parameter_tag<typename std::decay<Arg>::type>::value
+                : sub_value;
+        };
+
+        static inline bool is_parameter_tag_compatible(uint64_t a, uint64_t b)
+        {
+            if (a == 0)
+                return b == 0;
+            if (b == 0)
+                return a == 0;
+            int sa = a%6;
+            int sb = a%6;
+            if (sa == 5) sa = 4;
+            if (sb == 5) sb = 4;
+            if (sa != sb)
+                return false;
+            return is_parameter_tag_compatible(a/6, b/6);
+        }
+
+        static inline unsigned find_closing_tag_runtime(const char* s, unsigned p)
+        {
+            return
+                s[p] == 0
+                ? throw std::runtime_error("unmatched tag <") :
+                s[p] == '>'
+                ? p : find_closing_tag_runtime(s, p + 1);
+        }
+        
+        static inline uint64_t get_parameter_tag_runtime(const char* s, unsigned p = 0)
+        {
+            return
+                s[p] == 0
+                    ?  0 :
+                s[p] == '<' ? (
+                    std::strncmp(s+p, "<int>", 5) == 0
+                        ? get_parameter_tag_runtime(s, find_closing_tag_runtime(s, p)) * 6 + 1 :
+                    std::strncmp(s+p, "<uint>", 6) == 0
+                        ? get_parameter_tag_runtime(s, find_closing_tag_runtime(s, p)) * 6 + 2 :
+                    (std::strncmp(s+p, "<float>", 7) == 0 ||
+                    std::strncmp(s+p, "<double>", 8) == 0)
+                        ? get_parameter_tag_runtime(s, find_closing_tag_runtime(s, p)) * 6 + 3 :
+                    (std::strncmp(s+p, "<str>", 5) == 0 ||
+                    std::strncmp(s+p, "<string>", 8) == 0)
+                        ? get_parameter_tag_runtime(s, find_closing_tag_runtime(s, p)) * 6 + 4 :
+                    std::strncmp(s+p, "<path>", 6) == 0
+                        ? get_parameter_tag_runtime(s, find_closing_tag_runtime(s, p)) * 6 + 5 :
+                    throw std::runtime_error("invalid parameter type")
+                    ) :
+                get_parameter_tag_runtime(s, p+1);
+        }
+#ifndef CROW_MSVC_WORKAROUND
+        constexpr uint64_t get_parameter_tag(const_str s, unsigned p = 0)
+        {
+            return
+                p == s.size() 
+                    ?  0 :
+                s[p] == '<' ? ( 
+                    is_int(s, p)
+                        ? get_parameter_tag(s, find_closing_tag(s, p)) * 6 + 1 :
+                    is_uint(s, p)
+                        ? get_parameter_tag(s, find_closing_tag(s, p)) * 6 + 2 :
+                    is_float(s, p)
+                        ? get_parameter_tag(s, find_closing_tag(s, p)) * 6 + 3 :
+                    is_str(s, p)
+                        ? get_parameter_tag(s, find_closing_tag(s, p)) * 6 + 4 :
+                    is_path(s, p)
+                        ? get_parameter_tag(s, find_closing_tag(s, p)) * 6 + 5 :
+                    throw std::runtime_error("invalid parameter type")
+                    ) : 
+                get_parameter_tag(s, p+1);
+        }
+#endif
+
+        template <typename ... T>
+        struct S
+        {
+            template <typename U>
+            using push = S<U, T...>;
+            template <typename U>
+            using push_back = S<T..., U>;
+            template <template<typename ... Args> class U>
+            using rebind = U<T...>;
+        };
+template <typename F, typename Set>
+        struct CallHelper;
+        template <typename F, typename ...Args>
+        struct CallHelper<F, S<Args...>>
+        {
+            template <typename F1, typename ...Args1, typename = 
+                decltype(std::declval<F1>()(std::declval<Args1>()...))
+                >
+            static char __test(int);
+
+            template <typename ...>
+            static int __test(...);
+
+            static constexpr bool value = sizeof(__test<F, Args...>(0)) == sizeof(char);
+        };
+
+
+        template <int N>
+        struct single_tag_to_type
+        {
+        };
+
+        template <>
+        struct single_tag_to_type<1>
+        {
+            using type = int64_t;
+        };
+
+        template <>
+        struct single_tag_to_type<2>
+        {
+            using type = uint64_t;
+        };
+
+        template <>
+        struct single_tag_to_type<3>
+        {
+            using type = double;
+        };
+
+        template <>
+        struct single_tag_to_type<4>
+        {
+            using type = std::string;
+        };
+
+        template <>
+        struct single_tag_to_type<5>
+        {
+            using type = std::string;
+        };
+
+
+        template <uint64_t Tag> 
+        struct arguments
+        {
+            using subarguments = typename arguments<Tag/6>::type;
+            using type = 
+                typename subarguments::template push<typename single_tag_to_type<Tag%6>::type>;
+        };
+
+        template <> 
+        struct arguments<0>
+        {
+            using type = S<>;
+        };
+
+        template <typename ... T>
+        struct last_element_type
+        {
+            using type = typename std::tuple_element<sizeof...(T)-1, std::tuple<T...>>::type;
+        };
+
+
+        template <>
+        struct last_element_type<>
+        {
+        };
+
+
+        // from http://stackoverflow.com/questions/13072359/c11-compile-time-array-with-logarithmic-evaluation-depth
+        template<class T> using Invoke = typename T::type;
+
+        template<unsigned...> struct seq{ using type = seq; };
+
+        template<class S1, class S2> struct concat;
+
+        template<unsigned... I1, unsigned... I2>
+        struct concat<seq<I1...>, seq<I2...>>
+          : seq<I1..., (sizeof...(I1)+I2)...>{};
+
+        template<class S1, class S2>
+        using Concat = Invoke<concat<S1, S2>>;
+
+        template<unsigned N> struct gen_seq;
+        template<unsigned N> using GenSeq = Invoke<gen_seq<N>>;
+
+        template<unsigned N>
+        struct gen_seq : Concat<GenSeq<N/2>, GenSeq<N - N/2>>{};
+
+        template<> struct gen_seq<0> : seq<>{};
+        template<> struct gen_seq<1> : seq<0>{};
+
+        template <typename Seq, typename Tuple> 
+        struct pop_back_helper;
+
+        template <unsigned ... N, typename Tuple>
+        struct pop_back_helper<seq<N...>, Tuple>
+        {
+            template <template <typename ... Args> class U>
+            using rebind = U<typename std::tuple_element<N, Tuple>::type...>;
+        };
+
+        template <typename ... T>
+        struct pop_back //: public pop_back_helper<typename gen_seq<sizeof...(T)-1>::type, std::tuple<T...>>
+        {
+            template <template <typename ... Args> class U>
+            using rebind = typename pop_back_helper<typename gen_seq<sizeof...(T)-1>::type, std::tuple<T...>>::template rebind<U>;
+        };
+
+        template <>
+        struct pop_back<>
+        {
+            template <template <typename ... Args> class U>
+            using rebind = U<>;
+        };
+
+        // from http://stackoverflow.com/questions/2118541/check-if-c0x-parameter-pack-contains-a-type
+        template < typename Tp, typename... List >
+        struct contains : std::true_type {};
+
+        template < typename Tp, typename Head, typename... Rest >
+        struct contains<Tp, Head, Rest...>
+        : std::conditional< std::is_same<Tp, Head>::value,
+            std::true_type,
+            contains<Tp, Rest...>
+        >::type {};
+
+        template < typename Tp >
+        struct contains<Tp> : std::false_type {};
+
+        template <typename T>
+        struct empty_context
+        {
+        };
+
+        template <typename T>
+        struct promote
+        {
+            using type = T;
+        };
+
+#define CROW_INTERNAL_PROMOTE_TYPE(t1, t2) \
+        template<> \
+        struct promote<t1> \
+        {  \
+            using type = t2; \
+        }
+
+        CROW_INTERNAL_PROMOTE_TYPE(char, int64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(short, int64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(int, int64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(long, int64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(long long, int64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(unsigned char, uint64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(unsigned short, uint64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(unsigned int, uint64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(unsigned long, uint64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(unsigned long long, uint64_t);
+        CROW_INTERNAL_PROMOTE_TYPE(float, double);
+#undef CROW_INTERNAL_PROMOTE_TYPE
+
+        template <typename T>
+        using promote_t = typename promote<T>::type;
+
+    } // namespace black_magic
+
+    namespace detail
+    {
+
+        template <class T, std::size_t N, class... Args>
+        struct get_index_of_element_from_tuple_by_type_impl
+        {
+            static constexpr auto value = N;
+        };
+
+        template <class T, std::size_t N, class... Args>
+        struct get_index_of_element_from_tuple_by_type_impl<T, N, T, Args...>
+        {
+            static constexpr auto value = N;
+        };
+
+        template <class T, std::size_t N, class U, class... Args>
+        struct get_index_of_element_from_tuple_by_type_impl<T, N, U, Args...>
+        {
+            static constexpr auto value = get_index_of_element_from_tuple_by_type_impl<T, N + 1, Args...>::value;
+        };
+
+    } // namespace detail
+
+    namespace utility
+    {
+        template <class T, class... Args>
+        T& get_element_by_type(std::tuple<Args...>& t)
+        {
+            return std::get<detail::get_index_of_element_from_tuple_by_type_impl<T, 0, Args...>::value>(t);
+        }
+
+        template<typename T> 
+        struct function_traits;  
+
+#ifndef CROW_MSVC_WORKAROUND
+        template<typename T> 
+        struct function_traits : public function_traits<decltype(&T::operator())>
+        {
+            using parent_t = function_traits<decltype(&T::operator())>;
+            static const size_t arity = parent_t::arity;
+            using result_type = typename parent_t::result_type;
+            template <size_t i>
+            using arg = typename parent_t::template arg<i>;
+        
+        };  
+#endif
+
+        template<typename ClassType, typename R, typename ...Args> 
+        struct function_traits<R(ClassType::*)(Args...) const>
+        {
+            static const size_t arity = sizeof...(Args);
+
+            typedef R result_type;
+
+            template <size_t i>
+            using arg = typename std::tuple_element<i, std::tuple<Args...>>::type;
+        };
+
+        template<typename ClassType, typename R, typename ...Args> 
+        struct function_traits<R(ClassType::*)(Args...)>
+        {
+            static const size_t arity = sizeof...(Args);
+
+            typedef R result_type;
+
+            template <size_t i>
+            using arg = typename std::tuple_element<i, std::tuple<Args...>>::type;
+        };
+
+        template<typename R, typename ...Args> 
+        struct function_traits<std::function<R(Args...)>>
+        {
+            static const size_t arity = sizeof...(Args);
+
+            typedef R result_type;
+
+            template <size_t i>
+            using arg = typename std::tuple_element<i, std::tuple<Args...>>::type;
+        };
+
+    } // namespace utility
+}