Netstream: Use a std::variant

FEX-Emu · Jan 10, 2025 · 95ee828 · 95ee828
1 parent de5cdae
commit 95ee828
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Showing 3 changed files with 30 additions and 22 deletions.
diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/GdbServer.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/GdbServer.cpp
@@ -190,9 +190,9 @@ fextl::string GdbServer::ReadPacket() {
   // where any $ or # in the packet body are escaped ('}' followed by the char XORed with 0x20)
   // The checksum is a single unsigned byte sum of the data, hex encoded.
 
-  std::optional<Utils::NetStream::ReturnGet> c;
-  while ((c = CommsStream.get()).has_value() && !c->Hangup) {
-    switch (c->data) {
+  Utils::NetStream::ReturnGet c;
+  while ((c = CommsStream.get()).HasData()) {
+    switch (c.GetData()) {
     case '$': // start of packet
       if (packet.size() != 0) {
         LogMan::Msg::EFmt("Dropping unexpected data: \"{}\"", packet);
@@ -204,8 +204,8 @@ fextl::string GdbServer::ReadPacket() {
     case '}': // escape char
     {
       auto escaped = CommsStream.get();
-      if (escaped.has_value() && !escaped->Hangup) {
-        packet.push_back(escaped->data ^ 0x20);
+      if (escaped.HasData()) {
+        packet.push_back(escaped.GetData() ^ 0x20);
       } else {
         LogMan::Msg::EFmt("Received Invalid escape char: ${}", packet);
       }
@@ -224,7 +224,7 @@ fextl::string GdbServer::ReadPacket() {
       }
       break;
     }
-    default: packet.push_back(c->data); break;
+    default: packet.push_back(c.GetData()); break;
     }
   }
 
@@ -1396,9 +1396,9 @@ void GdbServer::GdbServerLoop() {
     HandledPacketType response {};
 
     // Outer server loop. Handles packet start, ACK/NAK and break
-    std::optional<Utils::NetStream::ReturnGet> c;
-    while (!CoreShuttingDown.load() && (c = CommsStream.get()).has_value() && !c->Hangup) {
-      switch (c->data) {
+    Utils::NetStream::ReturnGet c;
+    while (!CoreShuttingDown.load() && (c = CommsStream.get()).HasData()) {
+      switch (c.GetData()) {
       case '$': {
         auto packet = ReadPacket();
         response = ProcessPacket(packet);
@@ -1428,11 +1428,11 @@ void GdbServer::GdbServerLoop() {
         SendPacketPair({std::move(str), HandledPacketType::TYPE_ACK});
         break;
       }
-      default: LogMan::Msg::DFmt("GdbServer: Unexpected byte {} ({:02x})", c->data, c->data);
+      default: LogMan::Msg::DFmt("GdbServer: Unexpected byte {} ({:02x})", c.GetData(), c.GetData());
       }
     }
 
-    if (c.has_value() && c->Hangup) {
+    if (c.HasHangup()) {
       break;
     }
 

diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/NetStream.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/NetStream.cpp
@@ -10,11 +10,11 @@
 #include <unistd.h>
 
 namespace FEX::Utils {
-std::optional<NetStream::ReturnGet> NetStream::get() {
+NetStream::ReturnGet NetStream::get() {
   if (read_offset != receive_buffer.size() && read_offset != receive_offset) {
     auto Result = receive_buffer.at(read_offset);
     ++read_offset;
-    return ReturnGet {Result, false};
+    return NetStream::ReturnGet {Result};
   }
 
   if (read_offset == receive_buffer.size()) {
@@ -29,7 +29,7 @@ std::optional<NetStream::ReturnGet> NetStream::get() {
   auto Result = ppoll(&pfd, 1, nullptr, nullptr);
   if (Result > 0) {
     if (pfd.revents & POLLHUP) {
-      return ReturnGet {'\0', true};
+      return NetStream::ReturnGet {true};
     }
 
     const auto remaining_size = receive_buffer.size() - receive_offset;
@@ -38,19 +38,19 @@ std::optional<NetStream::ReturnGet> NetStream::get() {
       receive_offset += Result;
       auto Result = receive_buffer.at(read_offset);
       ++read_offset;
-      return ReturnGet {Result, false};
+      return NetStream::ReturnGet {Result};
     }
   }
 
-  return std::nullopt;
+  return NetStream::ReturnGet {false};
 }
 
 size_t NetStream::read(char* buf, size_t size) {
   size_t Read {};
   while (Read < size) {
     auto Result = get();
-    if (Result.has_value() && !Result->Hangup) {
-      buf[Read] = Result->data;
+    if (Result.HasData()) {
+      buf[Read] = Result.GetData();
       ++Read;
     } else {
       return Read;

diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/NetStream.h b/Source/Tools/LinuxEmulation/LinuxSyscalls/NetStream.h
@@ -6,6 +6,7 @@
 #include <FEXCore/fextl/vector.h>
 
 #include <optional>
+#include <variant>
 
 namespace FEX::Utils {
 class NetStream final {
@@ -25,11 +26,18 @@ class NetStream final {
     return socketfd != -1;
   }
 
-  struct ReturnGet {
-    char data;
-    bool Hangup;
+  struct ReturnGet final : public std::variant<char, bool> {
+    bool HasHangup() const {
+      return std::holds_alternative<bool>(*this) && std::get<bool>(*this);
+    }
+    bool HasData() const {
+      return std::holds_alternative<char>(*this);
+    }
+    char GetData() const {
+      return std::get<char>(*this);
+    }
   };
-  std::optional<ReturnGet> get();
+  ReturnGet get();
   size_t read(char* buf, size_t size);
 
   bool SendPacket(const fextl::string& packet);