From e0938690c7314ebc195e2a38f597d1c8da95f908 Mon Sep 17 00:00:00 2001
From: Green Sky <green@g-s.xyz>
Date: Mon, 19 Dec 2022 17:23:45 +0100
Subject: [PATCH] main thread com

---
 vim_research/test2.cpp | 68 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 59 insertions(+), 9 deletions(-)

diff --git a/vim_research/test2.cpp b/vim_research/test2.cpp
index b74b33a..bda49be 100644
--- a/vim_research/test2.cpp
+++ b/vim_research/test2.cpp
@@ -10,6 +10,7 @@ extern "C" {
 #include <optional>
 #include <memory>
 #include <unordered_map>
+#include <unordered_set>
 #include <string_view>
 #include <variant>
 #include <thread>
@@ -282,14 +283,21 @@ struct SharedContext {
 	ToxPubKey agent;
 	std::promise<void> agent_set;
 
-	// TODO: this is inefficent
-	std::mutex command_lists_mutex;
-	std::unordered_map<ToxPubKey, std::vector<Command>> command_lists;
-	// remote op queue for receive
-	// local op list for remote lookups
+	std::mutex command_lists_mutex; // for list and frontier!!
+	std::unordered_map<ToxPubKey, std::unordered_map<uint64_t, Command>> command_lists;
+	std::unordered_map<ToxPubKey, uint64_t> command_frontier; // last applied seq
 
-	// last seq for all known agents
-	// bool dirty
+	// contains remote changes we can apply in the main thread
+	std::mutex staging_mutex;
+	std::unordered_map<ToxPubKey, uint64_t> staging_frontier; // last seq we have in command_lists, via tox
+	// (can be lower then command_frontier for local agent
+
+	// contains remote changes with missing parent seq
+	// could merge into comamnd_lists
+	std::unordered_map<ToxPubKey, std::unordered_map<uint64_t, Command>> buffer;
+
+	std::atomic_bool should_gossip_local; // local changes (set by main thread, reset by tox thread)
+	std::unordered_set<ToxPubKey> should_gossip_remote; // list of ids we have new seq for (only modified by tox thread)
 
 	Tox* tox {nullptr};
 	bool tox_dht_online {false};
@@ -627,9 +635,31 @@ int main(void) {
 				// apply changes (some) and gen vim inserts
 				std::cout << "got fetch changes\n";
 
-				auto j_res_line_list = nlohmann::json::array();
+				bool changes {false};
+				{ // apply changes
+					// TODO: make less locky, we dont need to hold both at the same time etc
+					//std::lock_guard lg {ctx.staging_mutex};
+					std::scoped_lock sl {ctx.staging_mutex, ctx.command_lists_mutex};
 
-				if (true) { // external changes
+					// TODO: limit number of ops for responsiveness
+					for (const auto& [agent, staging_seq] : ctx.staging_frontier) {
+						// check if remote newer
+						if (!ctx.command_frontier.count(agent) || ctx.command_frontier.at(agent) < staging_seq) {
+							for (uint64_t seq = ctx.command_frontier[agent]; seq <= staging_seq; seq++) {
+
+								// !! this can get expensive, while we are holding locks :/
+								bool r = doc.apply(ctx.command_lists.at(agent).at(seq).ops);
+								assert(r && "this should not happen");
+							}
+
+							ctx.command_frontier[agent] = staging_seq;
+							changes = true;
+						}
+					}
+				}
+
+				auto j_res_line_list = nlohmann::json::array();
+				if (changes) { // external changes
 					const auto crdt_text = doc.getText();
 					std::string_view text_view {crdt_text};
 					for (int64_t i = 1; ; i++) {
@@ -692,6 +722,26 @@ int main(void) {
 					std::cout << "\n";
 				}
 				assert(doc.getText() == new_text);
+
+				// TODO: make something less locky
+				// TODO: make method
+				{
+					std::lock_guard mg{ctx.command_lists_mutex};
+					assert(ctx.command_lists.size() == ctx.command_frontier.size());
+
+					auto& local_command_list = ctx.command_lists[ctx.agent];
+					uint64_t seq {0};
+					if (ctx.command_frontier.count(ctx.agent)) { // get last own seq
+						seq = ctx.command_frontier[ctx.agent]++;
+					}
+					local_command_list.emplace(seq, Command{
+						ctx.agent,
+						seq,
+						ops
+					});
+					ctx.command_frontier[ctx.agent] = seq;
+				}
+				ctx.should_gossip_local.store(true);
 			} else {
 				std::cout << "unknown command '" << command << "'\n";
 			}