FEX-Emu--FEX/Source/Tools/LinuxEmulation/LinuxSyscalls/NetStream.cpp

// SPDX-License-Identifier: MIT
#include "LinuxSyscalls/NetStream.h"

#include <FEXCore/Utils/Allocator.h>
#include <FEXCore/Utils/LogManager.h>

#include <cstring>
#include <sys/socket.h>
#include <poll.h>
#include <unistd.h>

namespace FEX::Utils {
std::optional<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};
  }

  if (read_offset == receive_buffer.size()) {
    read_offset = 0;
    receive_offset = 0;
  }

  struct pollfd pfd {
    .fd = socketfd, .events = POLLIN, .revents = 0,
  };

  auto Result = ppoll(&pfd, 1, nullptr, nullptr);
  if (Result > 0) {
    if (pfd.revents & POLLHUP) {
      return ReturnGet {'\0', true};
    }

    const auto remaining_size = receive_buffer.size() - receive_offset;
    Result = ::recv(socketfd, &receive_buffer.at(receive_offset), remaining_size, 0);
    if (Result > 0) {
      receive_offset += Result;
      auto Result = receive_buffer.at(read_offset);
      ++read_offset;
      return ReturnGet {Result, false};
    }
  }

  return std::nullopt;
}

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;
      ++Read;
    } else {
      return Read;
    }
  }
  return Read;
}

bool NetStream::SendPacket(const fextl::string& packet) {
  size_t Total {};
  while (Total < packet.size()) {
    size_t Remaining = packet.size() - Total;
    size_t sent = ::send(socketfd, &packet.at(Total), Remaining, MSG_NOSIGNAL);
    if (sent == -1) {
      return false;
    }
    Total += sent;
  }

  return Total == packet.size();
}

} // namespace FEX::Utils