gossip p1 works, command 2 buffer works if not too large

vim_research/test2.cpp

@@ -1,3 +1,4 @@
+#include "toxcore/tox.h"
 #include <crdt/text_document.hpp>
 #include <nlohmann/json.hpp>
 
@@ -61,7 +62,7 @@ using Doc = GreenCRDT::TextDocument<Agent>;
 using ListType = Doc::ListType;
 
 struct Command {
-	Agent actor;
+	Agent agent;
 	uint64_t seq {0}; // independed of the ops inside, theoretically
 	//...
 	std::vector<Doc::Op> ops;
@@ -129,7 +130,7 @@ namespace std {
 } // namespace std
 
 NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(Command,
-	actor,
+	agent,
 	seq,
 	ops
 )
@@ -296,8 +297,9 @@ struct SharedContext {
 	// 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::atomic_bool should_gossip_local{false}; // 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)
+	std::unordered_map<ToxPubKey, uint64_t> heard_gossip; // seq frontiers we have heard about
 
 	Tox* tox {nullptr};
 	bool tox_dht_online {false};
@@ -307,6 +309,51 @@ struct SharedContext {
 
 namespace tox {
 
+namespace pkg {
+
+	enum PKGID : uint8_t {
+		FRONTIER = 32,
+		REQUEST_FRONTIER,
+
+		COMMAND,
+		REQUEST_COMMANDS,
+	};
+
+	// send the currently last known seq you have (excluding buffer)
+	struct Frontier {
+		Agent agent;
+		uint64_t seq{0};
+	};
+
+	NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(Frontier,
+		agent,
+		seq
+	)
+
+	// request the last known seq another peer has for agent
+	struct RequestFrontier {
+		Agent agent;
+	};
+
+	NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(RequestFrontier,
+		agent
+	)
+
+	using Command = ::Command;
+
+	// request every command for agent after seq (inclusive)
+	struct RequestCommands {
+		Agent agent;
+		uint64_t seq{0};
+	};
+
+	NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(RequestCommands,
+		agent,
+		seq
+	)
+
+} // namespace pkg
+
 static std::vector<uint8_t> hex2bin(const std::string& str) {
 	std::vector<uint8_t> bin{};
 	bin.resize(str.size()/2, 0);
@@ -390,6 +437,9 @@ void toxThread(SharedContext* ctx) {
 		}
 	}
 
+	// "thread local"
+	Agent agent_local;
+
 	//tox_group_self_get_public_key()
 	//tox_group_send_custom_packet()
 	//tox_group_send_custom_private_packet()
@@ -416,6 +466,7 @@ void toxThread(SharedContext* ctx) {
 					ctx->agent_set.set_value();
 					return; // fuck everything
 				}
+				agent_local = ctx->agent;
 				ctx->agent_set.set_value();
 			}
 		} else if (!ctx->tox_group_online) { // then wait for group to connect
@@ -424,9 +475,66 @@ void toxThread(SharedContext* ctx) {
 				std::cout << "tox connected to group\n";
 			}
 		} else { // do the thing
-			// staging?
+			// pump from buffer to staging
+
+			// request missing in buffer
+
+			// request frontier (implicit list of agents)
+			// only every couple of second, can get large
+			// OR get back random agent and do it often
+
 			// handle requests
-			// send tip (prio self)
+
+			{ // gossip frontier
+				// for mutex locking simplicity this is an either-or
+				if (ctx->should_gossip_local.exchange(false)) {
+					pkg::Frontier f_pkg{
+						agent_local,
+						0u
+					};
+
+					pkg::Command c_pkg{
+						agent_local,
+						0u,
+						{}
+					};
+
+					{ // lock
+						std::lock_guard lg{ctx->command_lists_mutex};
+						assert(ctx->command_frontier.count(agent_local));
+
+						f_pkg.seq = ctx->command_frontier.at(agent_local);
+
+						c_pkg = ctx->command_lists[agent_local][f_pkg.seq];
+					}
+
+					{ // gossip
+						std::vector<uint8_t> data = nlohmann::json::to_msgpack(f_pkg);
+						// prepend pkgid
+						data.emplace(data.begin(), static_cast<uint8_t>(pkg::PKGID::FRONTIER));
+
+						if (!tox_group_send_custom_packet(ctx->tox, 0, true, data.data(), data.size(), nullptr)) {
+							std::cerr << "failed to send gossip packet of local agent\n";
+							// TODO: set should_gossip_local back to true?
+						} else {
+							std::cout << "sent gossip of local agent\n";
+						}
+					}
+					{ // command
+						std::vector<uint8_t> data = nlohmann::json::to_msgpack(c_pkg);
+						// prepend pkgid
+						data.emplace(data.begin(), static_cast<uint8_t>(pkg::PKGID::COMMAND));
+
+						if (!tox_group_send_custom_packet(ctx->tox, 0, true, data.data(), data.size(), nullptr)) {
+							std::cerr << "failed to send command packet of local agent\n";
+						} else {
+							std::cout << "sent command of local agent\n";
+						}
+					}
+				} else if (!ctx->should_gossip_remote.empty()) {
+					std::lock_guard lg{ctx->command_lists_mutex};
+				}
+			}
 		}
 
 		std::this_thread::sleep_for(20ms);
@@ -751,7 +859,7 @@ int main(void) {
 					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]++;
+						seq = ctx.command_frontier[ctx.agent] + 1;
 					}
 					local_command_list.emplace(seq, Command{
 						ctx.agent,
@@ -789,14 +897,66 @@ static void self_connection_status_cb(Tox*, TOX_CONNECTION connection_status, vo
 	std::cout << "self_connection_status_cb " << connection_status << "\n";
 }
 
+static void handle_pkg(SharedContext& ctx, const uint8_t* data, size_t length) {
+	if (length < 2) {
+		std::cerr << "got too short pkg " << length << "\n";
+		return;
+	}
+
+	pkg::PKGID pkg_id = static_cast<pkg::PKGID>(data[0]);
+	const auto p_j = nlohmann::json::from_msgpack(data+1, data+1 + (length-1), true, false);
+	if (p_j.is_discarded()) {
+		std::cerr << "got invalid msgpack for " << pkg_id << "\n";
+		return;
+	}
+
+	std::cout << "pkg " << pkg_id << " j:" << p_j.dump() << "\n";
+
+	switch (pkg_id) {
+		case pkg::PKGID::FRONTIER: {
+			pkg::Frontier pkg = p_j;
+
+			if (!ctx.heard_gossip.count(pkg.agent) || ctx.heard_gossip[pkg.agent] < pkg.seq) {
+				ctx.heard_gossip[pkg.agent] = pkg.seq;
+				std::cout << "new seq " << pkg.seq << " from " << pkg.agent << "\n";
+			}
+			break;
+		}
+		case pkg::PKGID::REQUEST_FRONTIER: {
+			pkg::RequestFrontier pkg = p_j;
+			break;
+		}
+		case pkg::PKGID::COMMAND: {
+			pkg::Command pkg = p_j;
+
+			// push to buffer, if not in buffer
+			if (!ctx.buffer[pkg.agent].count(pkg.seq)) {
+				ctx.buffer[pkg.agent].emplace(pkg.seq, pkg);
+				std::cout << "pushed to buffer " << pkg.seq << " from " << pkg.agent << "\n";
+			}
+			// TODO: notify something?
+			break;
+		}
+		case pkg::PKGID::REQUEST_COMMANDS: {
+			pkg::RequestCommands pkg = p_j;
+			break;
+		}
+		default:
+			std::cerr << "unknown pkg id " << pkg_id << "\n";
+			break;
+	}
+}
+
 static void group_custom_packet_cb(Tox*, uint32_t group_number, uint32_t peer_id, const uint8_t* data, size_t length, void* user_data) {
 	std::cout << "group_custom_packet_cb\n";
 	SharedContext& ctx = *static_cast<SharedContext*>(user_data);
+	handle_pkg(ctx, data, length);
 }
 
 static void group_custom_private_packet_cb(Tox*, uint32_t group_number, uint32_t peer_id, const uint8_t* data, size_t length, void* user_data) {
 	std::cout << "group_custom_private_packet_cb\n";
 	SharedContext& ctx = *static_cast<SharedContext*>(user_data);
+	handle_pkg(ctx, data, length);
 }
 
 }