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#include "dvlnet/frame_queue.h"
#include <cstring>
#include "appfat.h"
#include "dvlnet/packet.h"
#include "utils/attributes.h"
#include "utils/endian_read.hpp"
#include "utils/endian_write.hpp"
namespace devilution {
namespace net {
namespace {
PacketError FrameQueueError()
{
return PacketError("Incorrect frame size");
}
} // namespace
framesize_t frame_queue::Size() const
{
return current_size;
}
tl::expected<buffer_t, PacketError> frame_queue::Read(framesize_t s)
{
if (current_size < s)
return tl::make_unexpected(FrameQueueError());
buffer_t ret;
while (s > 0 && s >= buffer_deque.front().size()) {
const framesize_t bufferSize = static_cast<framesize_t>(buffer_deque.front().size());
s -= bufferSize;
current_size -= bufferSize;
ret.insert(ret.end(),
buffer_deque.front().begin(),
buffer_deque.front().end());
buffer_deque.pop_front();
}
if (s > 0) {
ret.insert(ret.end(),
buffer_deque.front().begin(),
buffer_deque.front().begin() + s);
buffer_deque.front().erase(buffer_deque.front().begin(),
buffer_deque.front().begin() + s);
current_size -= s;
}
return ret;
}
void frame_queue::Write(buffer_t buf)
{
current_size += static_cast<framesize_t>(buf.size());
buffer_deque.push_back(std::move(buf));
}
tl::expected<bool, PacketError> frame_queue::PacketReady()
{
if (nextsize == 0) {
if (Size() < sizeof(framesize_t))
return false;
tl::expected<buffer_t, PacketError> szbuf = Read(sizeof(framesize_t));
if (!szbuf.has_value())
return tl::make_unexpected(szbuf.error());
nextsize = LoadLE32(szbuf->data());
if (nextsize == 0)
return tl::make_unexpected(FrameQueueError());
}
return Size() >= (nextsize & frame_size_mask);
}
uint16_t frame_queue::ReadPacketFlags()
{
static_assert(sizeof(nextsize) == 4, "framesize_t is not 4 bytes");
return static_cast<uint16_t>(nextsize >> 16);
}
tl::expected<buffer_t, PacketError> frame_queue::ReadPacket()
{
const framesize_t packetSize = nextsize & frame_size_mask;
if (nextsize == 0 || Size() < packetSize)
return tl::make_unexpected(FrameQueueError());
tl::expected<buffer_t, PacketError> ret = Read(packetSize);
nextsize = 0;
return ret;
}
tl::expected<buffer_t, PacketError> frame_queue::MakeFrame(buffer_t packetbuf, uint16_t flags)
{
buffer_t ret;
const framesize_t size = static_cast<framesize_t>(packetbuf.size());
if (size > max_frame_size)
return tl::make_unexpected("Buffer exceeds maximum frame size");
static_assert(sizeof(size) == 4, "framesize_t is not 4 bytes");
unsigned char sizeBuf[4];
WriteLE32(sizeBuf, size | (static_cast<framesize_t>(flags) << 16));
ret.insert(ret.end(), sizeBuf, sizeBuf + 4);
ret.insert(ret.end(), packetbuf.begin(), packetbuf.end());
return ret;
}
} // namespace net
} // namespace devilution