From 21b388f0d0e694d7cfa36a0ffb3f072f456e4f6e Mon Sep 17 00:00:00 2001
From: Kurt Sassenrath <kurt@sassenrath.me>
Date: Sun, 8 Oct 2023 08:20:23 -0700
Subject: [PATCH] WIP: Message definitions.

---
 include/parselink/msgpack/token/reader.h |  4 ++
 include/parselink/proto/message.h        | 63 ++++++++++++++++++++----
 tests/msgpack/test_speed.cpp             | 43 +++++++++++++++-
 3 files changed, 100 insertions(+), 10 deletions(-)

diff --git a/include/parselink/msgpack/token/reader.h b/include/parselink/msgpack/token/reader.h
index 5e5e395..7edd8d0 100644
--- a/include/parselink/msgpack/token/reader.h
+++ b/include/parselink/msgpack/token/reader.h
@@ -273,6 +273,10 @@ public:
         return token_buffer.subspan(0, parsed);
     }
 
+    template <typename T>
+    constexpr tl::expected<T, error> read() {
+    }
+
 private:
 
     std::span<std::byte const> data_;
diff --git a/include/parselink/proto/message.h b/include/parselink/proto/message.h
index 61bb25b..93e4b75 100644
--- a/include/parselink/proto/message.h
+++ b/include/parselink/proto/message.h
@@ -7,9 +7,9 @@
 //
 //----------------------------------------------------------------------------- 
 // Author: Kurt Sassenrath
-// Module: Message
+// Module: Proto
 //
-// Message types.
+// Message type definitions for the parselink protocol.
 //
 // Copyright (c) 2023 Kurt Sassenrath.
 //
@@ -19,18 +19,14 @@
 #define message_0c61530748b9f966
 
 #include <span>
+#include <string_view>
 #include <cstdint>
 
 #include <tl/expected.hpp>
+#include <variant>
 
 namespace parselink {
-namespace message {
-
-enum class error {
-    bad_magic,      // Did not get the message magic expected
-    too_large,      // The message size was too large.
-    unknown_type,   // The message type is not known
-};
+namespace proto {
 
 // Parselink messages are encoded with MessagePack and take the form of:
 // | magic | size | content |
@@ -38,6 +34,55 @@ enum class error {
 //      - [size] is the size of the message, not including this header.
 //      - [content] is [size] bytes of MessagePack data, including the
 //        specific type of message presented.
+// This may be revised in the future. The header could remain as msgpack, or
+// switch to something hand-crafted for saving bits.
+
+struct error_message {
+    std::uint32_t code;                 // An error code
+    std::string_view what;              // A string
+};
+
+// C->S: Request to (re)connect.
+struct connect_message {
+    std::uint32_t user_id;              // The user id.
+    std::uint32_t version;              // The version of the client.
+    std::span<std::byte> session_token; // An optional existing session token.
+};
+
+// S->C: Challenge to authenticate client as user_id
+struct challenge_message {
+    std::uint32_t version;
+    std::span<std::byte> challenge;
+};
+
+// C->S: Calculated response to a challenge.
+struct response_message {
+    std::span<std::byte> response;
+};
+
+// S->C: Session token.
+struct session_established_message {
+    std::span<std::byte> session_token;
+};
+
+struct parser_data_message {
+    std::string_view opts;
+    std::span<std::byte> payload;
+};
+
+using message = std::variant<
+    error_message,
+    connect_message,
+    challenge_message,
+    response_message,
+    session_established_message,
+    parser_data_message>;
+
+enum class error {
+    bad_magic,      // Did not get the message magic expected
+    too_large,      // The message size was too large.
+    unknown_type,   // The message type is not known
+};
 
 // This class is responsible for consuming buffer data and yielding a message
 // instance when complete. Will throw an error if data is incorrect.
diff --git a/tests/msgpack/test_speed.cpp b/tests/msgpack/test_speed.cpp
index b8efc28..44fdf17 100644
--- a/tests/msgpack/test_speed.cpp
+++ b/tests/msgpack/test_speed.cpp
@@ -1,6 +1,9 @@
 #include "parselink/msgpack/token.h"
+//#include "parselink/proto/message.h"
 
 #include <fmt/format.h>
+#include <fmt/ranges.h>
+#include <magic_enum.hpp>
 
 #include <chrono>
 #include <cstdlib>
@@ -9,6 +12,11 @@
 
 using namespace std::chrono_literals;
 
+struct any {
+    template <typename T>
+    operator T() {}
+};
+
 auto read_file(char const* filename) {
     std::vector<std::byte> data;
     auto fd = open(filename, O_RDONLY);
@@ -30,7 +38,7 @@ auto read_file(char const* filename) {
 
 int main(int argc, char** argv) {
 
-    std::array<msgpack::token, 4096> buf;
+    std::array<msgpack::token, 20> buf;
 
     auto data = read_file(argc < 2 ? "output.bin" : argv[1]);
 
@@ -41,6 +49,39 @@ int main(int argc, char** argv) {
     auto after = std::chrono::steady_clock::now();
     test.map([&](auto sp){
         fmt::print("Read {} tokens\n", sp.size());
+        for (auto token : sp) {
+            fmt::print("token type: {} value: ", magic_enum::enum_name(token.type()));
+            switch (token.type()) {
+                case msgpack::format::type::unsigned_int:
+                    fmt::print("{}", *(token.template get<std::uint64_t>()));
+                    break;
+                case msgpack::format::type::signed_int:
+                    fmt::print("{}", *(token.template get<std::int64_t>()));
+                    break;
+                case msgpack::format::type::boolean:
+                    fmt::print("{}", *(token.template get<bool>()));
+                    break;
+                case msgpack::format::type::string:
+                    fmt::print("{}", *(token.template get<std::string_view>()));
+                    break;
+                case msgpack::format::type::binary:
+                    fmt::print("{}", *(token.template get<std::span<std::byte const>>()));
+                    break;
+                case msgpack::format::type::map:
+                    fmt::print("map ({} entries)", token.template get<msgpack::map_desc>()->count);
+                    break;
+                case msgpack::format::type::array:
+                    fmt::print("array ({} entries)", token.template get<msgpack::array_desc>()->count);
+                    break;
+                case msgpack::format::type::nil:
+                    fmt::print("(nil)");
+                    break;
+                case msgpack::format::type::invalid:
+                    fmt::print("(invalid)");
+                    break;
+            }
+            fmt::print("\n");
+        }
     }).map_error([&](auto err){
         fmt::print("Failed to read tokens: {}\n", (int)err);
     });