From 98cef5e9a772602d42acfcf233838c760424db9a Mon Sep 17 00:00:00 2001
From: Nicolas James <Eele1Ephe7uZahRie@tutanota.com>
Date: Thu, 13 Feb 2025 18:00:17 +1100
Subject: initial commit

---
 comp3331/server/src/shared/connection.cc | 54 ++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 comp3331/server/src/shared/connection.cc

(limited to 'comp3331/server/src/shared/connection.cc')

diff --git a/comp3331/server/src/shared/connection.cc b/comp3331/server/src/shared/connection.cc
new file mode 100644
index 0000000..1063823
--- /dev/null
+++ b/comp3331/server/src/shared/connection.cc
@@ -0,0 +1,54 @@
+#include "shared/connection.hh"
+
+namespace shared {
+
+void connection::send_packet(packet&& packet) noexcept {
+    packet.header.sequence = this->seq_num;
+    shared::send_packet(packet, this->sock, this->info);
+    ++this->seq_num;
+
+    std::lock_guard<std::mutex> guard{*this->lock};
+    this->sent.push_back(packet);
+}
+
+bool connection::should_discard_packet(const packet& packet) noexcept {
+    std::lock_guard<std::mutex> guard{*this->lock};
+
+    // ack case
+    if (packet.header.command[0] == '\0') {
+        this->sent.erase(std::remove_if(std::begin(this->sent),
+                                        std::end(this->sent),
+                                        [&](const auto& p) {
+                                            return p.header.sequence <=
+                                                   packet.header.sequence;
+                                        }),
+                         std::end(this->sent));
+        return true;
+    }
+
+    // Send an ack for the packet if it's not an ack itself
+    auto ack_pkt = shared::contents_to_packet({}, "\0\0\0");
+    ack_pkt.header.sequence = packet.header.sequence;
+    shared::send_packet(ack_pkt, this->sock, this->info);
+
+    if (packet.header.sequence != this->ack_num) {
+        return true;
+    }
+    ++this->ack_num;
+    return false;
+}
+
+// Reliable transport reads our packets on a different thread and resends if
+// necessary.
+void connection::do_reliable_transport() noexcept {
+    while (!*this->should_thread_exit) {
+        std::this_thread::sleep_for(std::chrono::milliseconds(500));
+
+        std::lock_guard<std::mutex> guard{*this->lock};
+        for (const auto& packet : this->sent) {
+            shared::send_packet(packet, this->sock, this->info);
+        }
+    }
+}
+
+} // namespace shared
-- 
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