From 09b734344f31e18d0fa31c39acba6d012aa2cc56 Mon Sep 17 00:00:00 2001
From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Wed, 2 Sep 2015 23:40:21 +0200
Subject: [PATCH] tag packets withsequence numbers
acks are already transmitted to the other side,
but they're not used yet
---
src/net/Connection.hpp | 13 +++++++----
src/net/Packet.hpp | 7 ++++++
src/net/net.cpp | 52 +++++++++++++++++++++++++++++++++++++-----
3 files changed, 62 insertions(+), 10 deletions(-)
diff --git a/src/net/Connection.hpp b/src/net/Connection.hpp
index 49e9cda..ade65eb 100644
--- a/src/net/Connection.hpp
+++ b/src/net/Connection.hpp
@@ -1,8 +1,10 @@
#ifndef BLANK_NET_CONNECTION_HPP_
#define BLANK_NET_CONNECTION_HPP_
+#include "Packet.hpp"
#include "../app/IntervalTimer.hpp"
+#include <cstdint>
#include <SDL_net.h>
@@ -17,24 +19,27 @@ public:
bool Matches(const IPaddress &) const noexcept;
- void FlagSend() noexcept;
- void FlagRecv() noexcept;
-
bool ShouldPing() const noexcept;
bool TimedOut() const noexcept;
void Update(int dt);
-
void SendPing(UDPpacket &, UDPsocket);
void Send(UDPpacket &, UDPsocket);
+ void Received(const UDPpacket &);
+
+private:
+ void FlagSend() noexcept;
+ void FlagRecv() noexcept;
private:
IPaddress addr;
IntervalTimer send_timer;
IntervalTimer recv_timer;
+ Packet::TControl ctrl;
+
};
}
diff --git a/src/net/Packet.hpp b/src/net/Packet.hpp
index d547990..b7c8a5f 100644
--- a/src/net/Packet.hpp
+++ b/src/net/Packet.hpp
@@ -16,8 +16,15 @@ struct Packet {
LOGIN = 1,
};
+ struct TControl {
+ std::uint16_t seq;
+ std::uint16_t ack;
+ std::uint32_t hist;
+ };
+
struct Header {
std::uint32_t tag;
+ TControl ctrl;
std::uint8_t type;
} header;
diff --git a/src/net/net.cpp b/src/net/net.cpp
index 20b6f5c..314410e 100644
--- a/src/net/net.cpp
+++ b/src/net/net.cpp
@@ -75,7 +75,7 @@ void Client::HandlePacket(const UDPpacket &udp_pack) {
return;
}
- conn.FlagRecv();
+ conn.Received(udp_pack);
cout << "I got something!" << endl;
}
@@ -102,7 +102,8 @@ void Client::SendLogin(const string &name) {
Connection::Connection(const IPaddress &addr)
: addr(addr)
, send_timer(5000)
-, recv_timer(10000) {
+, recv_timer(10000)
+, ctrl{ 0, 0xFFFF, 0xFFFF } {
send_timer.Start();
recv_timer.Start();
}
@@ -133,14 +134,53 @@ void Connection::Update(int dt) {
}
-void Connection::Send(UDPpacket &pack, UDPsocket sock) {
- pack.address = addr;
- if (SDLNet_UDP_Send(sock, -1, &pack) == 0) {
+void Connection::Send(UDPpacket &udp_pack, UDPsocket sock) {
+ Packet &pack = *reinterpret_cast<Packet *>(udp_pack.data);
+ pack.header.ctrl = ctrl;
+
+ udp_pack.address = addr;
+ if (SDLNet_UDP_Send(sock, -1, &udp_pack) == 0) {
throw NetError("SDLNet_UDP_Send");
}
+
FlagSend();
}
+void Connection::Received(const UDPpacket &udp_pack) {
+ Packet &pack = *reinterpret_cast<Packet *>(udp_pack.data);
+
+ int diff = std::int16_t(pack.header.ctrl.seq) - std::int16_t(ctrl.ack);
+
+ if (diff > 0) {
+ // incoming more recent than last acked
+
+ // TODO: packets considered lost are detected here
+ // this should have ones for all of them:
+ // ~hist & ((1 << dist) - 1) if dist is < 32
+
+ if (diff >= 32) {
+ // missed more than the last 32 oO
+ ctrl.hist = 0;
+ } else {
+ ctrl.hist >>= diff;
+ ctrl.hist |= 1 << (32 - diff);
+ }
+ } else if (diff < 0) {
+ // incoming older than acked
+ if (diff > -32) {
+ // too late :/
+ } else {
+ ctrl.hist |= 1 << (32 + diff);
+ }
+ } else {
+ // incoming the same as last acked oO
+ }
+
+ ctrl.ack = pack.header.ctrl.seq;
+
+ FlagRecv();
+}
+
void Connection::SendPing(UDPpacket &udp_pack, UDPsocket sock) {
Packet &pack = *reinterpret_cast<Packet *>(udp_pack.data);
udp_pack.len = pack.Ping();
@@ -230,7 +270,7 @@ void Server::HandlePacket(const UDPpacket &udp_pack) {
}
Connection &client = GetClient(udp_pack.address);
- client.FlagRecv();
+ client.Received(udp_pack);
switch (pack.header.type) {
case Packet::PING:
--
2.39.5