string_view no copy and no serialize

include/rest_rpc/client.hpp

@@ -6,8 +6,10 @@
 #include "logger.hpp"
 #include "meta_util.hpp"
 #include "rest_rpc_protocol.hpp"
+#include "string_resize.hpp"
 #include "traits.h"
 #include "use_asio.hpp"
+#include "util.hpp"
 #include <asio/experimental/awaitable_operators.hpp>
 #include <asio/steady_timer.hpp>
 using namespace asio::experimental::awaitable_operators;
@@ -18,6 +20,10 @@ template <typename R> struct call_result {
   R value;
 };
 
+template <> struct call_result<void> {
+  rpc_errc ec;
+};
+
 class client {
 public:
   client() : socket_(get_global_executor()) {}
@@ -121,7 +127,9 @@ private:
     std::vector<asio::const_buffer> buffers;
     buffers.reserve(2);
     buffers.push_back(asio::buffer(&header, sizeof(rest_rpc_header)));
-    buffers.push_back(asio::buffer(buf.data(), buf.size()));
+    if constexpr (sizeof...(Args) > 0) {
+      buffers.push_back(asio::buffer(buf.data(), buf.size()));
+    }
 
     using R = typename function_traits<decltype(func)>::return_type;
     call_result<R> result{};
@@ -150,14 +158,19 @@ private:
 
     detail::resize(body_, resp_header.body_len);
     std::tie(ec, size) = co_await asio::async_read(
-        socket_, asio::buffer(body_), asio::as_tuple(asio::use_awaitable));
+        socket_, asio::buffer(body_.data(), body_.size()),
+        asio::as_tuple(asio::use_awaitable));
     if (ec) {
       REST_LOG_WARNING << "read body error: " << ec.message();
       result.ec = rpc_errc::read_error;
       co_return result;
     }
     result.ec = (rpc_errc)body_[0];
-    result.value = codec.unpack<R>(body_.data() + 1, resp_header.body_len - 1);
+    if constexpr (!std::is_void_v<R>) {
+      result.value = codec.unpack<R>(
+          std::string_view(body_.data() + 1, resp_header.body_len - 1));
+    }
+
     co_return result;
   }
 

include/rest_rpc/codec.h

@@ -1,19 +1,36 @@
 #ifndef REST_RPC_CODEC_H_
 #define REST_RPC_CODEC_H_
 
+#include "traits.h"
+#include <charconv>
 #include <msgpack.hpp>
 
 namespace rest_rpc {
 namespace rpc_service {
 
+template <typename Arg> auto pack_one(Arg &&arg) {
+  if constexpr (util::CharArrayRef<Arg> || util::CharArray<Arg> ||
+                util::string<Arg>) {
+    return std::string_view(std::forward<Arg>(arg));
+  } else {
+    return std::to_string(arg);
+  }
+}
+
 using buffer_type = msgpack::sbuffer;
 struct msgpack_codec {
   const static size_t init_size = 2 * 1024;
 
-  template <typename... Args> static buffer_type pack_args(Args &&...args) {
-    buffer_type buffer(init_size);
-    msgpack::pack(buffer, std::forward_as_tuple(std::forward<Args>(args)...));
-    return buffer;
+  template <typename... Args> static auto pack_args(Args &&...args) {
+    if constexpr (sizeof...(Args) == 0) {
+      return std::string_view{};
+    } else if constexpr (sizeof...(Args) == 1 && util::is_basic_v<Args...>) {
+      return pack_one(std::forward<Args>(args)...);
+    } else {
+      buffer_type buffer(init_size);
+      msgpack::pack(buffer, std::forward_as_tuple(std::forward<Args>(args)...));
+      return buffer;
+    }
   }
 
   template <typename Arg> static std::string pack_to_string(Arg &arg) {
@@ -46,6 +63,23 @@ struct msgpack_codec {
     }
   }
 
+  template <typename T> T unpack(std::string_view data) {
+    if constexpr (std::is_fundamental_v<T>) {
+      T t;
+      auto r = std::from_chars(data.data(), data.data() + data.size(), t);
+      if (r.ec != std::errc()) {
+        throw std::invalid_argument("unpack failed: Args not match!");
+      }
+      return t;
+    } else if constexpr (std::is_same_v<std::string, T>) {
+      return std::string(data);
+    } else if constexpr (std::is_same_v<std::string_view, T>) {
+      return data;
+    } else {
+      return unpack<T>(data.data(), data.size());
+    }
+  }
+
 private:
   msgpack::unpacked msg_;
 };

include/rest_rpc/cplusplus_14.h

@@ -79,9 +79,10 @@ auto apply_helper(F &&f, Tuple &&tp, nonstd::index_sequence<Idx...>)
 }
 
 template <typename F, typename Tuple>
-auto apply(F &&f, Tuple &&tp) -> decltype(apply_helper(
-    std::forward<F>(f), std::forward<Tuple>(tp),
-    make_index_sequence<std::tuple_size<decay_t<Tuple>>::value>{})) {
+auto apply(F &&f, Tuple &&tp)
+    -> decltype(apply_helper(
+        std::forward<F>(f), std::forward<Tuple>(tp),
+        make_index_sequence<std::tuple_size<decay_t<Tuple>>::value>{})) {
   return apply_helper(
       std::forward<F>(f), std::forward<Tuple>(tp),
       make_index_sequence<std::tuple_size<decay_t<Tuple>>::value>{});

include/rest_rpc/meta_util.hpp

@@ -28,7 +28,7 @@ struct function_traits<Ret(Arg, Args...)> {
 public:
   enum { arity = sizeof...(Args) + 1 };
   typedef Ret function_type(Arg, Args...);
-  typedef Ret return_type;
+  typedef std::remove_cvref_t<Ret> return_type;
   using stl_function_type = std::function<function_type>;
   typedef Ret (*pointer)(Arg, Args...);
 
@@ -51,7 +51,7 @@ template <typename Ret> struct function_traits<Ret()> {
 public:
   enum { arity = 0 };
   typedef Ret function_type();
-  typedef Ret return_type;
+  typedef std::remove_cvref_t<Ret> return_type;
   using stl_function_type = std::function<function_type>;
   typedef Ret (*pointer)();
 
@@ -123,7 +123,9 @@ using nth_type_of = nonstd::tuple_element_t<N, std::tuple<Args...>>;
 template <typename... Args>
 using last_type_of = nth_type_of<sizeof...(Args) - 1, Args...>;
 
-template <typename T> struct remove_first { using type = T; };
+template <typename T> struct remove_first {
+  using type = T;
+};
 
 template <class First, class... Second>
 struct remove_first<std::tuple<First, Second...>> {

include/rest_rpc/nonstd_any.hpp

@@ -38,7 +38,7 @@
 #define any_HAVE_TWEAK_HEADER 1
 #else
 #define any_HAVE_TWEAK_HEADER 0
-//# pragma message("any.hpp: Note: Tweak header not supported.")
+// # pragma message("any.hpp: Note: Tweak header not supported.")
 #endif
 
 // any selection and configuration:
@@ -251,7 +251,7 @@ using std::swap;
 #endif
 
 // half-open range [lo..hi):
-//#define any_BETWEEN( v, lo, hi ) ( (lo) <= (v) && (v) < (hi) )
+// #define any_BETWEEN( v, lo, hi ) ( (lo) <= (v) && (v) < (hi) )
 
 // Presence of language and library features:
 
@@ -387,7 +387,9 @@ using std::tr1::add_const;
 
 #else
 
-template <class T> struct add_const { typedef const T type; };
+template <class T> struct add_const {
+  typedef const T type;
+};
 
 #endif // any_HAVE_ADD_CONST
 
@@ -401,8 +403,12 @@ using std::tr1::remove_reference;
 
 #else
 
-template <class T> struct remove_reference { typedef T type; };
-template <class T> struct remove_reference<T &> { typedef T type; };
+template <class T> struct remove_reference {
+  typedef T type;
+};
+template <class T> struct remove_reference<T &> {
+  typedef T type;
+};
 
 #endif // any_HAVE_REMOVE_REFERENCE
 

include/rest_rpc/rest_rpc_protocol.hpp

@@ -6,6 +6,14 @@
 #include <arpa/inet.h>
 #endif
 
+inline uint64_t htonll(uint64_t value) {
+  return ((uint64_t)htonl(value & 0xFFFFFFFF) << 32) | htonl(value >> 32);
+}
+
+inline uint64_t ntohll(uint64_t value) {
+  return ((uint64_t)ntohl(value & 0xFFFFFFFF) << 32) | ntohl(value >> 32);
+}
+
 namespace rest_rpc {
 inline constexpr uint8_t REST_MAGIC_NUM = 39;
 struct rest_rpc_header {

include/rest_rpc/rpc_connection.hpp

@@ -32,24 +32,29 @@ public:
       }
 
       detail::resize(body_, header.body_len);
-      std::tie(ec, size) = co_await asio::async_read(
-          socket_, asio::buffer(body_), asio::as_tuple(asio::use_awaitable));
-      if (ec) {
-        REST_LOG_WARNING << "read body error: " << ec.message();
-        break;
+
+      if (header.body_len > 0) {
+        std::tie(ec, size) = co_await asio::async_read(
+            socket_, asio::buffer(body_), asio::as_tuple(asio::use_awaitable));
+        if (ec) {
+          REST_LOG_WARNING << "read body error: " << ec.message();
+          break;
+        }
       }
 
       // route
       auto result = router_.route(header.function_id, body_);
       rest_rpc_header resp_header{};
       resp_header.magic = 39;
-      resp_header.body_len = result.result.size() + 1;
+      resp_header.body_len = result.size() + 1;
       prepare_for_send(resp_header);
       std::vector<asio::const_buffer> buffers;
       buffers.reserve(3);
       buffers.push_back(asio::buffer(&resp_header, sizeof(rest_rpc_header)));
       buffers.push_back(asio::buffer(&result.ec, 1));
-      buffers.push_back(asio::buffer(result.result));
+      if (!result.empty())
+        buffers.push_back(asio::buffer(result.data()));
+
       std::tie(ec, size) = co_await asio::async_write(
           socket_, buffers, asio::as_tuple(asio::use_awaitable));
       if (ec) {

include/rest_rpc/rpc_router.hpp

@@ -1,9 +1,9 @@
 #pragma once
 #include "codec.h"
 #include "error_code.h"
-#include "function_name.h"
-#include "md5.hpp"
+
 #include "meta_util.hpp"
+#include "util.hpp"
 #include <cstdint>
 #include <functional>
 #include <string>
@@ -13,13 +13,12 @@ namespace rest_rpc {
 struct rpc_result {
   rpc_errc ec = rpc_errc::ok;
   std::string result;
-};
+  std::string_view view;
+  bool empty() { return result.empty() && view.empty(); }
+  size_t size() { return result.empty() ? view.size() : result.size(); }
 
-template <auto func> constexpr uint32_t get_key() {
-  constexpr auto name = get_func_name<func>();
-  constexpr uint32_t key = MD5::MD5Hash32(name.data(), name.length());
-  return key;
-}
+  std::string_view data() { return result.empty() ? view : result; }
+};
 
 class rpc_router {
 public:
@@ -57,30 +56,28 @@ public:
 
   rpc_result route(uint32_t key, std::string_view data) {
     rpc_result route_result{};
-    std::string result;
     try {
       rpc_service::msgpack_codec codec;
       auto it = map_invokers_.find(key);
       if (it == map_invokers_.end()) {
-        result = "unknown function: " + get_name_by_key(key);
+        route_result.result = "unknown function: " + get_name_by_key(key);
         route_result.ec = rpc_errc::no_such_function;
       } else {
-        it->second(data, route_result.ec, result);
+        it->second(data, route_result);
         route_result.ec = rpc_errc::ok;
       }
     } catch (const std::exception &ex) {
       rpc_service::msgpack_codec codec;
-      result = std::string("exception occur when call").append(ex.what());
+      route_result.result =
+          std::string("exception occur when call").append(ex.what());
       route_result.ec = rpc_errc::function_exception;
     } catch (...) {
       rpc_service::msgpack_codec codec;
-      result = std::string("unknown exception occur when call ")
-                   .append(get_name_by_key(key));
+      route_result.result = std::string("unknown exception occur when call ")
+                                .append(get_name_by_key(key));
       route_result.ec = rpc_errc::function_unknown_exception;
     }
 
-    route_result.result = std::move(result);
-
     return route_result;
   }
 
@@ -103,65 +100,116 @@ private:
   template <typename Function>
   void register_nonmember_func(uint32_t key, Function f) {
     this->map_invokers_[key] = [f = std::move(f)](std::string_view str,
-                                                  rpc_errc &ec,
-                                                  std::string &result) mutable {
+                                                  rpc_result &ret) mutable {
       using args_tuple = typename function_traits<Function>::tuple_type;
       using R = typename function_traits<Function>::return_type;
-      rpc_service::msgpack_codec codec;
+
       try {
-        auto tp = codec.unpack<args_tuple>(str.data(), str.size());
-        if constexpr (std::is_void_v<R>) {
-          std::apply(f, tp);
+        if constexpr (std::tuple_size_v<args_tuple> == 0) {
+          if constexpr (std::is_void_v<R>) {
+            f();
+          } else {
+            auto r = f();
+            ret.result = rpc_service::msgpack_codec::pack_to_string(r);
+          }
         } else {
-          auto r = std::apply(f, tp);
-          result = rpc_service::msgpack_codec::pack_to_string(r);
+          rpc_service::msgpack_codec codec;
+          using first_t = std::tuple_element_t<0, args_tuple>;
+          if constexpr (std::tuple_size_v<args_tuple> == 1 &&
+                        util::is_basic_v<first_t>) {
+            if constexpr (std::is_void_v<R>) {
+              f(codec.unpack<first_t>(str));
+            } else {
+              if constexpr (std::is_same_v<std::string_view, R>) {
+                ret.view = rpc_service::msgpack_codec::pack_args(
+                    f(codec.unpack<first_t>(str)));
+              } else {
+                ret.result = rpc_service::msgpack_codec::pack_args(
+                    f(codec.unpack<first_t>(str)));
+              }
+            }
+          } else {
+            auto tp = codec.unpack<args_tuple>(str);
+            if constexpr (std::is_void_v<R>) {
+              std::apply(f, tp);
+            } else {
+              auto r = std::apply(f, tp);
+              ret.result = rpc_service::msgpack_codec::pack_to_string(r);
+            }
+          }
         }
       } catch (std::invalid_argument &e) {
-        ec = rpc_errc::invalid_argument;
-        result = e.what();
+        ret.ec = rpc_errc::invalid_argument;
+        ret.result = e.what();
       } catch (const std::exception &e) {
-        ec = rpc_errc::function_exception;
-        result = e.what();
+        ret.ec = rpc_errc::function_exception;
+        ret.result = e.what();
       }
     };
   }
 
   template <typename Function, typename Self>
   void register_member_func(uint32_t key, const Function &f, Self *self) {
-    this->map_invokers_[key] = [f, self](std::string_view str, rpc_errc &ec,
-                                         std::string &result) {
+    this->map_invokers_[key] = [f, self](std::string_view str,
+                                         rpc_result &ret) {
       using args_tuple = typename function_traits<Function>::tuple_type;
       using R = typename function_traits<Function>::return_type;
       rpc_service::msgpack_codec codec;
       try {
-        auto tp = codec.unpack<args_tuple>(str.data(), str.size());
-
-        if constexpr (std::is_void_v<R>) {
-          std::apply(
-              [self, &f](auto &&...args) {
-                return (*self.*f)(std::forward<decltype(args)>(args)...);
-              },
-              tp);
+        if constexpr (std::tuple_size_v<args_tuple> == 0) {
+          if constexpr (std::is_void_v<R>) {
+            (*self.*f)();
+          } else {
+            auto r = (*self.*f)();
+            ret.result = rpc_service::msgpack_codec::pack_to_string(r);
+          }
         } else {
-          auto r = std::apply(
-              [self, &f](auto &&...args) {
-                return (*self.*f)(std::forward<decltype(args)>(args)...);
-              },
-              tp);
-          result = rpc_service::msgpack_codec::pack_to_string(r);
+          using first_t = std::tuple_element_t<0, args_tuple>;
+          if constexpr (std::tuple_size_v<args_tuple> == 1 &&
+                        util::is_basic_v<first_t>) {
+            if constexpr (std::is_void_v<R>) {
+              (*self.*f)(codec.unpack<first_t>(str));
+            } else {
+              if constexpr (std::is_same_v<std::string_view, R>) {
+                ret.view = rpc_service::msgpack_codec::pack_args(
+                    (*self.*f)(codec.unpack<first_t>(str)));
+              } else {
+                ret.result = rpc_service::msgpack_codec::pack_args(
+                    (*self.*f)(codec.unpack<first_t>(str)));
+              }
+            }
+          } else {
+            auto tp = codec.unpack<args_tuple>(str);
+
+            if constexpr (std::is_void_v<R>) {
+              std::apply(
+                  [self, &f](auto &&...args) {
+                    return (*self.*f)(std::forward<decltype(args)>(args)...);
+                  },
+                  tp);
+            } else {
+              auto r = std::apply(
+                  [self, &f](auto &&...args) {
+                    return (*self.*f)(std::forward<decltype(args)>(args)...);
+                  },
+                  tp);
+              ret.result = rpc_service::msgpack_codec::pack_to_string(r);
+            }
+          }
         }
+
       } catch (std::invalid_argument &e) {
-        ec = rpc_errc::invalid_argument;
-        result = e.what();
+        ret.ec = rpc_errc::invalid_argument;
+        ret.result = e.what();
       } catch (const std::exception &e) {
-        ec = rpc_errc::function_exception;
-        result = e.what();
+        ret.ec = rpc_errc::function_exception;
+        ret.result = e.what();
       }
     };
   }
 
-  std::unordered_map<uint32_t, std::function<void(std::string_view, rpc_errc &,
-                                                  std::string &)>>
+  std::unordered_map<uint32_t,
+                     std::function<void(std::string_view, rpc_result &)>>
       map_invokers_;
   std::unordered_map<uint32_t, std::string> key2func_name_;
 };

include/rest_rpc/traits.h

@@ -145,7 +145,9 @@ struct is_invocable
 template <typename F, typename... Args>
 inline constexpr bool is_invocable_v = is_invocable<F, Args...>::value;
 
-template <typename T> struct remove_first { using type = T; };
+template <typename T> struct remove_first {
+  using type = T;
+};
 
 template <class First, class... Second>
 struct remove_first<std::tuple<First, Second...>> {
@@ -171,4 +173,44 @@ struct is_specialization<Ref<Args...>, Ref> : std::true_type {};
 
 template <typename Test, template <typename...> class Ref>
 inline constexpr bool is_specialization_v = is_specialization<Test, Ref>::value;
+
+template <typename Type>
+concept container = requires(Type container) {
+  typename std::remove_cvref_t<Type>::value_type;
+  container.size();
+  container.begin();
+  container.end();
+};
+
+template <typename Type>
+constexpr bool is_char_t =
+    std::is_same_v<Type, signed char> || std::is_same_v<Type, char> ||
+    std::is_same_v<Type, unsigned char> || std::is_same_v<Type, wchar_t> ||
+    std::is_same_v<Type, char16_t> || std::is_same_v<Type, char32_t>
+#ifdef __cpp_lib_char8_t
+    || std::is_same_v<Type, char8_t>
+#endif
+    ;
+
+template <typename Type>
+concept string = container<Type> && requires(Type container) {
+  requires is_char_t<typename std::remove_cvref_t<Type>::value_type>;
+  container.length();
+  container.data();
+};
+
+template <typename T>
+concept CharArrayRef = requires {
+  requires std::is_array_v<std::remove_reference_t<T>> &&
+               std::same_as<std::remove_extent_t<std::remove_cvref_t<T>>, char>;
+};
+
+template <typename T>
+concept CharArray =
+    std::is_array_v<std::remove_reference_t<T>> &&
+    std::same_as<std::remove_extent_t<std::remove_cvref_t<T>>, char>;
+
+template <typename T, typename...>
+inline constexpr bool is_basic_v =
+    std::is_fundamental_v<T> || string<T> || CharArray<T> || CharArrayRef<T>;
 } // namespace rest_rpc::util

include/rest_rpc/util.hpp

@@ -0,0 +1,11 @@
+#pragma once
+#include "function_name.h"
+#include "md5.hpp"
+
+namespace rest_rpc {
+template <auto func> constexpr uint32_t get_key() {
+  constexpr auto name = get_func_name<func>();
+  constexpr uint32_t key = MD5::MD5Hash32(name.data(), name.length());
+  return key;
+}
+} // namespace rest_rpc