asio HTTP implementation (#23)

asio-based HTTP implementation

21 files changed, 1375 insertions, 164 deletions

diff --git a/vcpkg.json b/vcpkg.json
index 45910556a..4a0c41d3b 100644
--- a/vcpkg.json
+++ b/vcpkg.json
@@ -21,7 +21,6 @@
       "features": [ "lz4", "zstd" ]
     },
     "sol2",
-    "sentry-native",
-    "uwebsockets"
+    "sentry-native"
   ]
 }
diff --git a/xmake.lua b/xmake.lua
index 9d44ec8d0..ced2b55ce 100644
--- a/xmake.lua
+++ b/xmake.lua
@@ -17,10 +17,7 @@ add_requires(
     "vcpkg::curl", 
     "vcpkg::zlib", 
     "vcpkg::zstd", 
-    "vcpkg::http-parser", 
-    "vcpkg::uwebsockets", 
-    "vcpkg::usockets",
-    "vcpkg::libuv")
+    "vcpkg::http-parser")
 
 add_rules("mode.debug", "mode.release")
 
diff --git a/zencore/include/zencore/iobuffer.h b/zencore/include/zencore/iobuffer.h
index 5fbeaeaeb..db462e238 100644
--- a/zencore/include/zencore/iobuffer.h
+++ b/zencore/include/zencore/iobuffer.h
@@ -374,6 +374,7 @@ public:
 	ZENCORE_API static IoBuffer MakeFromFile(const path_char_t* FileName, uint64_t Offset = 0, uint64_t Size = ~0ull);
 	ZENCORE_API static IoBuffer MakeFromTemporaryFile(const std::filesystem::path& FileName);
 	ZENCORE_API static IoBuffer MakeFromFileHandle(void* FileHandle, uint64_t Offset = 0, uint64_t Size = ~0ull);
+	ZENCORE_API static IoBuffer ReadFromFileMaybe(IoBuffer& InBuffer);
 	inline static IoBuffer		MakeCloneFromMemory(const void* Ptr, size_t Sz) { return IoBuffer(IoBuffer::Clone, Ptr, Sz); }
 };
 
diff --git a/zencore/include/zencore/string.h b/zencore/include/zencore/string.h
index c205b199d..a94e063a4 100644
--- a/zencore/include/zencore/string.h
+++ b/zencore/include/zencore/string.h
@@ -619,9 +619,23 @@ HashStringDjb2(const std::string_view& InString)
 {
 	uint32_t HashValue = 5381;
 
-	for (int c : InString)
+	for (int CurChar : InString)
 	{
-		HashValue = HashValue * 33 + c;
+		HashValue = HashValue * 33 + CurChar;
+	}
+
+	return HashValue;
+}
+
+constexpr uint32_t
+HashStringAsLowerDjb2(const std::string_view& InString)
+{
+	uint32_t HashValue = 5381;
+
+	for (int CurChar : InString)
+	{
+		CurChar -= ((CurChar - 'A') <= ('Z' - 'A')) * ('A' - 'a');	// this should be compiled into branchless logic
+		HashValue = HashValue * 33 + CurChar;
 	}
 
 	return HashValue;
@@ -634,9 +648,9 @@ ToLower(const std::string_view& InString)
 {
 	std::string Out(InString);
 
-	for (char& C : Out)
+	for (char& CurChar : Out)
 	{
-		C = static_cast<char>(std::tolower(C));
+		CurChar -= ((CurChar - 'A') <= ('Z' - 'A')) * ('A' - 'a');	// this should be compiled into branchless logic
 	}
 
 	return Out;
diff --git a/zencore/include/zencore/thread.h b/zencore/include/zencore/thread.h
index 410ffbd1e..9fc4c87a2 100644
--- a/zencore/include/zencore/thread.h
+++ b/zencore/include/zencore/thread.h
@@ -6,10 +6,13 @@
 
 #include <shared_mutex>
 
+#include <string_view>
 #include <vector>
 
 namespace zen {
 
+void SetCurrentThreadName(std::string_view ThreadName);
+
 /**
  * Reader-writer lock
  *
diff --git a/zencore/iobuffer.cpp b/zencore/iobuffer.cpp
index 922c14f83..119e37d0b 100644
--- a/zencore/iobuffer.cpp
+++ b/zencore/iobuffer.cpp
@@ -144,7 +144,7 @@ IoBufferCore::MakeOwned(bool Immutable)
 {
 	if (!IsOwned())
 	{
-		const void* OldDataPtr	 = m_DataPtr;
+		const void* OldDataPtr = m_DataPtr;
 		AllocateBuffer(m_DataBytes, sizeof(void*));
 		memcpy(const_cast<void*>(m_DataPtr), OldDataPtr, m_DataBytes);
 		SetIsOwnedByThis(true);
@@ -188,29 +188,29 @@ IoBufferExtendedCore::~IoBufferExtendedCore()
 {
 	if (m_MappedPointer)
 	{
-#	if ZEN_PLATFORM_WINDOWS
+#if ZEN_PLATFORM_WINDOWS
 		UnmapViewOfFile(m_MappedPointer);
-#	else
+#else
 		uint64_t MapSize = ~uint64_t(uintptr_t(m_MmapHandle));
 		munmap(m_MappedPointer, MapSize);
-#	endif
+#endif
 	}
 
-#	if ZEN_PLATFORM_WINDOWS
+#if ZEN_PLATFORM_WINDOWS
 	if (m_Flags & kOwnsMmap)
 	{
 		CloseHandle(m_MmapHandle);
 	}
-#	endif
+#endif
 
 	if (m_Flags & kOwnsFile)
 	{
-#	if ZEN_PLATFORM_WINDOWS
+#if ZEN_PLATFORM_WINDOWS
 		BOOL Success = CloseHandle(m_FileHandle);
-#	else
+#else
 		int	 Fd		 = int(uintptr_t(m_FileHandle));
 		bool Success = (close(Fd) == 0);
-#	endif
+#endif
 
 		if (!Success)
 		{
@@ -244,7 +244,7 @@ IoBufferExtendedCore::Materialize() const
 	const uint64_t MappedOffsetDisplacement = m_FileOffset - MapOffset;
 	const uint64_t MapSize					= m_DataBytes + MappedOffsetDisplacement;
 
-#	if ZEN_PLATFORM_WINDOWS
+#if ZEN_PLATFORM_WINDOWS
 	m_MmapHandle = CreateFileMapping(m_FileHandle,
 									 /* lpFileMappingAttributes */ nullptr,
 									 /* flProtect */ PAGE_READONLY,
@@ -265,7 +265,7 @@ IoBufferExtendedCore::Materialize() const
 									 /* FileOffsetHigh */ uint32_t(MapOffset >> 32),
 									 /* FileOffsetLow */ uint32_t(MapOffset & 0xffFFffFFu),
 									 /* dwNumberOfBytesToMap */ MapSize);
-#	else
+#else
 	m_MmapHandle = (void*)uintptr_t(~MapSize);	// ~ so it's never null (assuming MapSize >= 0)
 	m_Flags |= kOwnsMmap;
 
@@ -276,7 +276,7 @@ IoBufferExtendedCore::Materialize() const
 		/* flags */ MAP_SHARED | MAP_NORESERVE,
 		/* fd */ int(uintptr_t(m_FileHandle)),
 		/* offset */ MapOffset);
-#	endif	// ZEN_PLATFORM_WINDOWS
+#endif	// ZEN_PLATFORM_WINDOWS
 
 	if (MappedBase == nullptr)
 	{
@@ -371,6 +371,41 @@ IoBuffer::GetFileReference(IoBufferFileReference& OutRef) const
 //////////////////////////////////////////////////////////////////////////
 
 IoBuffer
+IoBufferBuilder::ReadFromFileMaybe(IoBuffer& InBuffer)
+{
+	IoBufferFileReference FileRef;
+	if (InBuffer.GetFileReference(/* out */ FileRef))
+	{
+		IoBuffer OutBuffer(FileRef.FileChunkSize);
+
+#if ZEN_PLATFORM_WINDOWS
+		OVERLAPPED Ovl{};
+
+		const uint64_t	NumberOfBytesToRead = FileRef.FileChunkSize;
+		const uint64_t& FileOffset			= FileRef.FileChunkOffset;
+
+		Ovl.Offset	   = DWORD(FileOffset & 0xffff'ffffu);
+		Ovl.OffsetHigh = DWORD(FileOffset >> 32);
+
+		DWORD dwNumberOfBytesRead = 0;
+		BOOL  Success = ::ReadFile(FileRef.FileHandle, OutBuffer.MutableData(), DWORD(NumberOfBytesToRead), &dwNumberOfBytesRead, &Ovl);
+
+		ZEN_ASSERT(dwNumberOfBytesRead == NumberOfBytesToRead);
+
+		// TODO: error handling
+
+		return OutBuffer;
+#else
+#	error Needs implementation
+#endif
+	}
+	else
+	{
+		return InBuffer;
+	}
+}
+
+IoBuffer
 IoBufferBuilder::MakeFromFileHandle(void* FileHandle, uint64_t Offset, uint64_t Size)
 {
 	return IoBuffer(IoBuffer::BorrowedFile, FileHandle, Offset, Size);
@@ -381,7 +416,7 @@ IoBufferBuilder::MakeFromFile(const path_char_t* FileName, uint64_t Offset, uint
 {
 	uint64_t FileSize;
 
-#	if ZEN_PLATFORM_WINDOWS
+#if ZEN_PLATFORM_WINDOWS
 	CAtlFile DataFile;
 
 	HRESULT hRes = DataFile.Create(FileName, GENERIC_READ, FILE_SHARE_READ, OPEN_EXISTING);
@@ -392,7 +427,7 @@ IoBufferBuilder::MakeFromFile(const path_char_t* FileName, uint64_t Offset, uint
 	}
 
 	DataFile.GetSize((ULONGLONG&)FileSize);
-#	else
+#else
 	int Fd = open(FileName, O_RDONLY);
 	if (Fd < 0)
 	{
@@ -403,7 +438,7 @@ IoBufferBuilder::MakeFromFile(const path_char_t* FileName, uint64_t Offset, uint
 	struct stat Stat;
 	fstat(Fd, &Stat);
 	FileSize = Stat.st_size;
-#	endif	// ZEN_PLATFORM_WINDOWS
+#endif	// ZEN_PLATFORM_WINDOWS
 
 	// TODO: should validate that offset is in range
 
@@ -422,15 +457,15 @@ IoBufferBuilder::MakeFromFile(const path_char_t* FileName, uint64_t Offset, uint
 
 	if (Size)
 	{
-#	if ZEN_PLATFORM_WINDOWS
+#if ZEN_PLATFORM_WINDOWS
 		void* Fd = DataFile.Detach();
-#	endif
+#endif
 		return IoBuffer(IoBuffer::File, (void*)uintptr_t(Fd), Offset, Size);
 	}
 
-#	if !ZEN_PLATFORM_WINDOWS
+#if !ZEN_PLATFORM_WINDOWS
 	close(Fd);
-#	endif
+#endif
 
 	// For an empty file, we may as well just return an empty memory IoBuffer
 	return IoBuffer(IoBuffer::Wrap, "", 0);
@@ -442,7 +477,7 @@ IoBufferBuilder::MakeFromTemporaryFile(const std::filesystem::path& FileName)
 	uint64_t FileSize;
 	void*	 Handle;
 
-#	if ZEN_PLATFORM_WINDOWS
+#if ZEN_PLATFORM_WINDOWS
 	CAtlFile DataFile;
 
 	// We need to open with DELETE since this is used for the case
@@ -459,7 +494,7 @@ IoBufferBuilder::MakeFromTemporaryFile(const std::filesystem::path& FileName)
 	DataFile.GetSize((ULONGLONG&)FileSize);
 
 	Handle = DataFile.Detach();
-#	else
+#else
 	int Fd = open(FileName.native().c_str(), O_RDONLY);
 	if (Fd < 0)
 	{
@@ -472,7 +507,7 @@ IoBufferBuilder::MakeFromTemporaryFile(const std::filesystem::path& FileName)
 	FileSize = Stat.st_size;
 
 	Handle = (void*)uintptr_t(Fd);
-#	endif	// ZEN_PLATFORM_WINDOWS
+#endif	// ZEN_PLATFORM_WINDOWS
 
 	IoBuffer Iob(IoBuffer::File, Handle, 0, FileSize);
 	Iob.m_Core->SetIsWholeFile(true);
@@ -489,7 +524,7 @@ HashBuffer(IoBuffer& Buffer)
 
 //////////////////////////////////////////////////////////////////////////
 
-#	if ZEN_WITH_TESTS
+#if ZEN_WITH_TESTS
 
 void
 iobuffer_forcelink()
@@ -503,6 +538,6 @@ TEST_CASE("IoBuffer")
 	zen::IoBuffer buffer3(buffer2, 0, buffer2.Size());
 }
 
-#	endif
+#endif
 
 }  // namespace zen
diff --git a/zencore/string.cpp b/zencore/string.cpp
index 49824a910..8e7921bb6 100644
--- a/zencore/string.cpp
+++ b/zencore/string.cpp
@@ -929,6 +929,13 @@ TEST_CASE("string")
 {
 	using namespace std::literals;
 
+	SUBCASE("hash_djb2")
+	{
+		CHECK(HashStringAsLowerDjb2("AbcdZ"sv) == HashStringDjb2("abcdz"sv));
+		CHECK(HashStringAsLowerDjb2("aBCd"sv) == HashStringDjb2("abcd"sv));
+		CHECK(HashStringAsLowerDjb2("aBCd"sv) == HashStringDjb2(ToLower("aBCd"sv)));
+	}
+
 	SUBCASE("ForEachStrTok")
 	{
 		const auto		   Tokens			  = "here,is,my,different,tokens"sv;
diff --git a/zencore/thread.cpp b/zencore/thread.cpp
index 20ab19f56..6f27ee528 100644
--- a/zencore/thread.cpp
+++ b/zencore/thread.cpp
@@ -14,6 +14,61 @@
 
 namespace zen {
 
+#if ZEN_PLATFORM_WINDOWS
+// The information on how to set the thread name comes from
+// a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
+const DWORD kVCThreadNameException = 0x406D1388;
+typedef struct tagTHREADNAME_INFO
+{
+	DWORD  dwType;		// Must be 0x1000.
+	LPCSTR szName;		// Pointer to name (in user addr space).
+	DWORD  dwThreadID;	// Thread ID (-1=caller thread).
+	DWORD  dwFlags;		// Reserved for future use, must be zero.
+} THREADNAME_INFO;
+// The SetThreadDescription API was brought in version 1607 of Windows 10.
+typedef HRESULT(WINAPI* SetThreadDescription)(HANDLE hThread, PCWSTR lpThreadDescription);
+// This function has try handling, so it is separated out of its caller.
+void
+SetNameInternal(DWORD thread_id, const char* name)
+{
+	THREADNAME_INFO info;
+	info.dwType		= 0x1000;
+	info.szName		= name;
+	info.dwThreadID = thread_id;
+	info.dwFlags	= 0;
+	__try
+	{
+		RaiseException(kVCThreadNameException, 0, sizeof(info) / sizeof(DWORD), reinterpret_cast<DWORD_PTR*>(&info));
+	}
+	__except (EXCEPTION_CONTINUE_EXECUTION)
+	{
+	}
+}
+#endif
+
+void
+SetCurrentThreadName([[maybe_unused]] std::string_view ThreadName)
+{
+#if ZEN_PLATFORM_WINDOWS
+	// The SetThreadDescription API works even if no debugger is attached.
+	static auto SetThreadDescriptionFunc =
+		reinterpret_cast<SetThreadDescription>(::GetProcAddress(::GetModuleHandle(L"Kernel32.dll"), "SetThreadDescription"));
+
+	if (SetThreadDescriptionFunc)
+	{
+		SetThreadDescriptionFunc(::GetCurrentThread(), Utf8ToWide(ThreadName).c_str());
+	}
+	// The debugger needs to be around to catch the name in the exception.  If
+	// there isn't a debugger, we are just needlessly throwing an exception.
+	if (!::IsDebuggerPresent())
+		return;
+
+	std::string ThreadNameZ{ThreadName};
+	SetNameInternal(GetCurrentThreadId(), ThreadNameZ.c_str());
+#else
+#endif
+}  // namespace zen
+
 void
 RwLock::AcquireShared()
 {
diff --git a/zenhttp/httpasio.cpp b/zenhttp/httpasio.cpp
new file mode 100644
index 000000000..015d32633
--- /dev/null
+++ b/zenhttp/httpasio.cpp
@@ -0,0 +1,1125 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include "httpasio.h"
+
+#include <zenhttp/httpserver.h>
+
+#include <conio.h>
+#include <zencore/logging.h>
+
+#include <http_parser.h>
+#include <asio.hpp>
+#include <deque>
+
+namespace zen::asio_http {
+
+using namespace std::literals;
+using namespace fmt::literals;
+
+struct HttpAcceptor;
+struct HttpRequest;
+struct HttpResponse;
+struct HttpServerConnection;
+
+static constinit uint32_t HashContentLength = HashStringAsLowerDjb2("Content-Length"sv);
+static constinit uint32_t HashContentType	= HashStringAsLowerDjb2("Content-Type"sv);
+static constinit uint32_t HashAccept		= HashStringAsLowerDjb2("Accept"sv);
+static constinit uint32_t HashSession		= HashStringAsLowerDjb2("UE-Session"sv);
+static constinit uint32_t HashRequest		= HashStringAsLowerDjb2("UE-Request"sv);
+
+inline spdlog::logger&
+InitLogger()
+{
+	spdlog::logger& Logger = logging::Get("asio");
+//	Logger.set_level(spdlog::level::trace);
+	return Logger;
+}
+
+inline spdlog::logger&
+Log()
+{
+	static spdlog::logger& g_Logger = InitLogger();
+	return g_Logger;
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+struct HttpAsioServerImpl
+{
+public:
+	HttpAsioServerImpl();
+	~HttpAsioServerImpl();
+
+	void		 Start(uint16_t Port, int ThreadCount);
+	void		 Stop();
+	void		 RegisterService(const char* UrlPath, HttpService& Service);
+	HttpService* RouteRequest(std::string_view Url);
+
+	asio::io_service						 m_IoService;
+	asio::io_service::work					 m_Work{m_IoService};
+	std::unique_ptr<asio_http::HttpAcceptor> m_Acceptor;
+	std::vector<std::thread>				 m_ThreadPool;
+
+	struct ServiceEntry
+	{
+		std::string	 ServiceUrlPath;
+		HttpService* Service;
+	};
+
+	RwLock					  m_Lock;
+	std::vector<ServiceEntry> m_UriHandlers;
+};
+
+/**
+ * This is the class which request handlers use to interact with the server instance
+ */
+
+class HttpAsioServerRequest : public HttpServerRequest
+{
+public:
+	HttpAsioServerRequest(asio_http::HttpRequest& Request, HttpService& Service, IoBuffer PayloadBuffer);
+	~HttpAsioServerRequest();
+
+	virtual Oid		 ParseSessionId() const override;
+	virtual uint32_t ParseRequestId() const override;
+
+	virtual IoBuffer ReadPayload() override;
+	virtual void	 WriteResponse(HttpResponseCode ResponseCode) override;
+	virtual void	 WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::span<IoBuffer> Blobs) override;
+	virtual void	 WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::u8string_view ResponseString) override;
+	virtual void	 WriteResponseAsync(std::function<void(HttpServerRequest&)>&& ContinuationHandler) override;
+
+	using HttpServerRequest::WriteResponse;
+
+	HttpAsioServerRequest(const HttpAsioServerRequest&) = delete;
+	HttpAsioServerRequest& operator=(const HttpAsioServerRequest&) = delete;
+
+	asio_http::HttpRequest&		  m_Request;
+	IoBuffer					  m_PayloadBuffer;
+	std::string_view			  m_QueryString;
+	std::unique_ptr<HttpResponse> m_Response;
+};
+
+struct HttpRequest
+{
+	explicit HttpRequest(HttpServerConnection& Connection) : m_Connection(Connection) {}
+
+	void   Initialize();
+	size_t ConsumeData(const char* InputData, size_t DataSize);
+
+	void ResetState();
+
+	HttpVerb		 RequestVerb() const { return m_RequestVerb; }
+	bool			 IsKeepAlive() const { return m_KeepAlive; }
+	std::string_view Url() const { return std::string_view(m_Url, m_UrlLength); }
+	IoBuffer		 Body() { return m_BodyBuffer; }
+
+	inline HttpContentType ContentType()
+	{
+		if (m_ContentTypeHeaderIndex < 0)
+		{
+			return HttpContentType::kUnknownContentType;
+		}
+
+		return ParseContentType(m_Headers[m_ContentTypeHeaderIndex].Value);
+	}
+
+	inline HttpContentType AcceptType()
+	{
+		if (m_AcceptHeaderIndex < 0)
+		{
+			return HttpContentType::kUnknownContentType;
+		}
+
+		return ParseContentType(m_Headers[m_AcceptHeaderIndex].Value);
+	}
+
+	Oid SessionId() const { return m_SessionId; }
+	int RequestId() const { return m_RequestId; }
+
+private:
+	struct HeaderEntry
+	{
+		std::string_view Name;
+		std::string_view Value;
+	};
+
+	HttpServerConnection&	 m_Connection;
+	char					 m_HeaderBuffer[512];
+	char*					 m_HeaderCursor				= m_HeaderBuffer;
+	char*					 m_Url						= nullptr;
+	size_t					 m_UrlLength				= 0;
+	char*					 m_CurrentHeaderName		= nullptr;	// Used while parsing headers
+	size_t					 m_CurrentHeaderNameLength	= 0;
+	char*					 m_CurrentHeaderValue		= nullptr;	// Used while parsing headers
+	size_t					 m_CurrentHeaderValueLength = 0;
+	std::vector<HeaderEntry> m_Headers;
+	int8_t					 m_ContentLengthHeaderIndex;
+	int8_t					 m_AcceptHeaderIndex;
+	int8_t					 m_ContentTypeHeaderIndex;
+	int						 m_RequestId = -1;
+	Oid						 m_SessionId{};
+	IoBuffer				 m_BodyBuffer;
+	uint64_t				 m_BodyPosition;
+	http_parser				 m_Parser;
+	HttpVerb				 m_RequestVerb;
+	bool					 m_KeepAlive = false;
+
+	void AppendInputBytes(const char* Data, size_t Bytes);
+	void AppendCurrentHeader();
+
+	int OnMessageBegin();
+	int OnUrl(const char* Data, size_t Bytes);
+	int OnHeader(const char* Data, size_t Bytes);
+	int OnHeaderValue(const char* Data, size_t Bytes);
+	int OnHeadersComplete();
+	int OnBody(const char* Data, size_t Bytes);
+	int OnMessageComplete();
+
+	static HttpRequest*			GetThis(http_parser* Parser) { return reinterpret_cast<HttpRequest*>(Parser->data); }
+	static http_parser_settings s_ParserSettings;
+
+	void TerminateConnection();
+};
+
+struct HttpResponse
+{
+public:
+	HttpResponse() = default;
+	explicit HttpResponse(HttpContentType ContentType) : m_ContentType(ContentType) {}
+
+	void InitializeForPayload(uint16_t ResponseCode, std::span<IoBuffer> BlobList)
+	{
+		m_ResponseCode			  = ResponseCode;
+		const uint32_t ChunkCount = gsl::narrow<uint32_t>(BlobList.size());
+
+		m_DataBuffers.reserve(ChunkCount);
+
+		for (IoBuffer& Buffer : BlobList)
+		{
+#if 1
+			m_DataBuffers.emplace_back(std::move(Buffer)).MakeOwned();
+#else
+			IoBuffer TempBuffer = std::move(Buffer);
+			TempBuffer.MakeOwned();
+			m_DataBuffers.emplace_back(IoBufferBuilder::ReadFromFileMaybe(TempBuffer));
+#endif
+		}
+
+		uint64_t LocalDataSize = 0;
+
+		m_AsioBuffers.push_back({});  // Placeholder for header
+
+		for (IoBuffer& Buffer : m_DataBuffers)
+		{
+			uint64_t BufferDataSize = Buffer.Size();
+
+			ZEN_ASSERT(BufferDataSize);
+
+			LocalDataSize += BufferDataSize;
+
+			IoBufferFileReference FileRef;
+			if (Buffer.GetFileReference(/* out */ FileRef))
+			{
+				// TODO: Use direct file transfer, via TransmitFile/sendfile
+				//
+				// this looks like it requires some custom asio plumbing however
+
+				m_AsioBuffers.push_back({Buffer.Data(), Buffer.Size()});
+			}
+			else
+			{
+				// Send from memory
+
+				m_AsioBuffers.push_back({Buffer.Data(), Buffer.Size()});
+			}
+		}
+		m_ContentLength = LocalDataSize;
+
+		auto Headers	 = GetHeaders();
+		m_AsioBuffers[0] = asio::const_buffer(Headers.data(), Headers.size());
+	}
+
+	uint16_t ResponseCode() const { return m_ResponseCode; }
+	uint64_t ContentLength() const { return m_ContentLength; }
+
+	const std::vector<asio::const_buffer>& AsioBuffers() const { return m_AsioBuffers; }
+
+	std::string_view GetHeaders()
+	{
+		m_Headers << "HTTP/1.1 " << ResponseCode() << " " << ReasonStringForHttpResultCode(ResponseCode()) << "\r\n"
+				  << "Content-Type: " << MapContentTypeToString(m_ContentType) << "\r\n"
+				  << "Content-Length: " << ContentLength() << "\r\n";
+
+		if (!m_IsKeepAlive)
+		{
+			m_Headers << "Connection: close\r\n";
+		}
+
+		m_Headers << "Date: Mon, 11 Oct 2021 15:06:32 GMT\r\n\r\n";	 // TODO: produce more believable data
+
+		return m_Headers;
+	}
+
+	void SuppressPayload() { m_AsioBuffers.resize(1); }
+
+private:
+	uint16_t						m_ResponseCode	= 0;
+	bool							m_IsKeepAlive	= true;
+	HttpContentType					m_ContentType	= HttpContentType::kBinary;
+	uint64_t						m_ContentLength = 0;
+	std::vector<IoBuffer>			m_DataBuffers;
+	std::vector<asio::const_buffer> m_AsioBuffers;
+	ExtendableStringBuilder<160>	m_Headers;
+};
+
+//////////////////////////////////////////////////////////////////////////
+
+struct HttpServerConnection
+{
+	HttpServerConnection(HttpAsioServerImpl& Server, std::unique_ptr<asio::ip::tcp::socket>&& Socket);
+	~HttpServerConnection();
+
+	void HandleNewRequest();
+	void TerminateConnection();
+	void HandleRequest();
+
+private:
+	enum class RequestState
+	{
+		kInitialState,
+		kInitialRead,
+		kReadingMore,
+		kWriting,
+		kWritingFinal,
+		kDone,
+		kTerminated
+	};
+
+	RequestState m_RequestState = RequestState::kInitialState;
+	HttpRequest	 m_RequestData{*this};
+
+	void EnqueueRead();
+	void OnDataReceived(const asio::error_code& Ec, std::size_t ByteCount);
+	void OnResponseDataSent(const asio::error_code& Ec, std::size_t ByteCount, bool Pop = false);
+	void OnError();
+
+	HttpAsioServerImpl&					   m_Server;
+	asio::streambuf						   m_RequestBuffer;
+	std::unique_ptr<asio::ip::tcp::socket> m_Socket;
+	std::atomic<uint32_t>				   m_RequestCounter{0};
+	uint32_t							   m_ConnectionId = 0;
+
+	RwLock									  m_ResponsesLock;
+	std::deque<std::unique_ptr<HttpResponse>> m_Responses;
+};
+
+std::atomic<uint32_t> g_ConnectionIdCounter{0};
+
+HttpServerConnection::HttpServerConnection(HttpAsioServerImpl& Server, std::unique_ptr<asio::ip::tcp::socket>&& Socket)
+: m_Server(Server)
+, m_Socket(std::move(Socket))
+, m_ConnectionId(g_ConnectionIdCounter.fetch_add(1))
+{
+	ZEN_TRACE("new connection #{}", m_ConnectionId);
+}
+
+HttpServerConnection::~HttpServerConnection()
+{
+}
+
+void
+HttpServerConnection::HandleNewRequest()
+{
+	m_RequestData.Initialize();
+
+	EnqueueRead();
+}
+
+void
+HttpServerConnection::TerminateConnection()
+{
+	m_RequestState = RequestState::kTerminated;
+
+	std::error_code Ec;
+	m_Socket->close(Ec);
+}
+
+void
+HttpServerConnection::EnqueueRead()
+{
+	if (m_RequestState == RequestState::kInitialRead)
+	{
+		m_RequestState = RequestState::kReadingMore;
+	}
+	else
+	{
+		m_RequestState = RequestState::kInitialRead;
+	}
+
+	m_RequestBuffer.prepare(64 * 1024);
+
+	asio::async_read(*m_Socket.get(),
+					 m_RequestBuffer,
+					 asio::transfer_at_least(16),
+					 [this](const asio::error_code& Ec, std::size_t ByteCount) {
+						 if (Ec)
+						 {
+							 if (m_RequestState == RequestState::kDone || m_RequestState == RequestState::kInitialRead)
+							 {
+								 // Expected, just silently handle the condition
+								 //
+								 // if we get an I/O error on the boundary between two messages
+								 // it should be fine to just not say anything
+
+								 ZEN_TRACE("(expected) socket read error: conn#{} '{}'", m_ConnectionId, Ec.message());
+							 }
+							 else
+							 {
+								 ZEN_WARN("unexpected socket read error: conn#{} {}", m_ConnectionId, Ec.message());
+							 }
+
+							 delete this;
+						 }
+						 else
+						 {
+							 ZEN_TRACE("read: conn#:{} seq#:{} t:{} bytes:{}",
+									   m_ConnectionId,
+									   m_RequestCounter.load(std::memory_order_relaxed),
+									   GetCurrentThreadId(),
+									   ByteCount);
+
+							 OnDataReceived(Ec, ByteCount);
+						 }
+					 });
+}
+
+void
+HttpServerConnection::OnDataReceived(const asio::error_code& Ec, std::size_t ByteCount)
+{
+	ZEN_UNUSED(ByteCount);
+
+	if (Ec)
+	{
+		ZEN_ERROR("OnDataReceived Error: {}", Ec.message());
+
+		return OnError();
+	}
+
+	while (m_RequestBuffer.size())
+	{
+		const asio::const_buffer& InputBuffer = m_RequestBuffer.data();
+
+		size_t Result = m_RequestData.ConsumeData((const char*)InputBuffer.data(), InputBuffer.size());
+
+		m_RequestBuffer.consume(Result);
+	}
+
+	switch (m_RequestState)
+	{
+		case RequestState::kDone:
+		case RequestState::kWritingFinal:
+		case RequestState::kTerminated:
+			break;
+
+		default:
+			EnqueueRead();
+			break;
+	}
+}
+
+void
+HttpServerConnection::OnResponseDataSent(const asio::error_code& Ec, std::size_t ByteCount, bool Pop)
+{
+	ZEN_UNUSED(ByteCount);
+	if (Ec)
+	{
+		ZEN_ERROR("OnResponseDataSent Error: {}", Ec.message());
+		return OnError();
+	}
+	else
+	{
+		if (!m_RequestData.IsKeepAlive())
+		{
+			m_RequestState = RequestState::kDone;
+
+			m_Socket->close();
+		}
+		else if (Pop)
+		{
+			RwLock::ExclusiveLockScope _(m_ResponsesLock);
+			m_Responses.pop_front();
+		}
+	}
+}
+
+void
+HttpServerConnection::OnError()
+{
+	m_Socket->close();
+}
+
+void
+HttpServerConnection::HandleRequest()
+{
+	if (!m_RequestData.IsKeepAlive())
+	{
+		m_RequestState = RequestState::kWritingFinal;
+
+		std::error_code Ec;
+		m_Socket->shutdown(asio::socket_base::shutdown_receive, Ec);
+
+		if (Ec)
+		{
+			ZEN_WARN("socket shutdown reported error: {}", Ec.message());
+		}
+	}
+	else
+	{
+		m_RequestState = RequestState::kWriting;
+	}
+
+	const uint32_t RequestNum = m_RequestCounter.load(std::memory_order_relaxed);
+	m_RequestCounter.fetch_add(1);
+
+	if (HttpService* Service = m_Server.RouteRequest(m_RequestData.Url()))
+	{
+		HttpAsioServerRequest Request(m_RequestData, *Service, m_RequestData.Body());
+
+		ZEN_TRACE("Handling request: Conn#{} Req#{}", m_ConnectionId, RequestNum);
+
+		Service->HandleRequest(Request);
+
+		if (std::unique_ptr<HttpResponse> Response = std::move(Request.m_Response))
+		{
+			// Transmit the response
+
+			if (m_RequestData.RequestVerb() == HttpVerb::kHead)
+			{
+				Response->SuppressPayload();
+			}
+
+			auto ResponseBuffers = Response->AsioBuffers();
+
+			uint64_t ResponseLength = 0;
+
+			for (auto& Buffer : ResponseBuffers)
+			{
+				ResponseLength += Buffer.size();
+			}
+
+			{
+				RwLock::ExclusiveLockScope _(m_ResponsesLock);
+				m_Responses.push_back(std::move(Response));
+			}
+
+			// TODO: should cork/uncork for Linux?
+
+			asio::async_write(*m_Socket.get(),
+							  ResponseBuffers,
+							  asio::transfer_exactly(ResponseLength),
+							  [this, RequestNum](const asio::error_code& Ec, std::size_t ByteCount) {
+								  ZEN_TRACE("Response sent: Conn#{} Req#{} ({})", m_ConnectionId, RequestNum, NiceBytes(ByteCount));
+								  OnResponseDataSent(Ec, ByteCount, true);
+							  });
+
+			return;
+		}
+	}
+
+	if (m_RequestData.RequestVerb() == HttpVerb::kHead)
+	{
+		std::string_view Response =
+			"HTTP/1.1 404 NOT FOUND\r\n"
+			"Date: Mon, 11 Oct 2021 15:06:32 GMT\r\n\r\n"sv;
+
+		if (!m_RequestData.IsKeepAlive())
+		{
+			Response =
+				"HTTP/1.1 404 NOT FOUND\r\n"
+				"Date: Mon, 11 Oct 2021 15:06:32 GMT\r\nConnection: close\r\n\r\n"sv;
+		}
+
+		asio::async_write(*m_Socket.get(), asio::buffer(Response), [this](const asio::error_code& Ec, std::size_t ByteCount) {
+			OnResponseDataSent(Ec, ByteCount);
+		});
+	}
+	else
+	{
+		std::string_view Response =
+			"HTTP/1.1 404 NOT FOUND\r\n"
+			"Content-Length: 23\r\nContent-Type: text/plain\r\nDate: Mon, 11 Oct 2021 15:06:32 GMT\r\n\r\nNo suitable route found"sv;
+
+		if (!m_RequestData.IsKeepAlive())
+		{
+			Response =
+				"HTTP/1.1 404 NOT FOUND\r\n"
+				"Content-Length: 23\r\nContent-Type: text/plain\r\nDate: Mon, 11 Oct 2021 15:06:32 GMT\r\nConnection: close\r\n\r\nNo suitable route found"sv;
+		}
+
+		asio::async_write(*m_Socket.get(), asio::buffer(Response), [this](const asio::error_code& Ec, std::size_t ByteCount) {
+			OnResponseDataSent(Ec, ByteCount);
+		});
+	}
+}
+
+//////////////////////////////////////////////////////////////////////////
+//
+// HttpRequest
+//
+
+http_parser_settings HttpRequest::s_ParserSettings{
+	.on_message_begin = [](http_parser* p) { return GetThis(p)->OnMessageBegin(); },
+	.on_url			  = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnUrl(Data, ByteCount); },
+	.on_status =
+		[](http_parser* p, const char* Data, size_t ByteCount) {
+			ZEN_UNUSED(p, Data, ByteCount);
+			return 0;
+		},
+	.on_header_field	 = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnHeader(Data, ByteCount); },
+	.on_header_value	 = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnHeaderValue(Data, ByteCount); },
+	.on_headers_complete = [](http_parser* p) { return GetThis(p)->OnHeadersComplete(); },
+	.on_body			 = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnBody(Data, ByteCount); },
+	.on_message_complete = [](http_parser* p) { return GetThis(p)->OnMessageComplete(); },
+	.on_chunk_header{},
+	.on_chunk_complete{}};
+
+void
+HttpRequest::Initialize()
+{
+	http_parser_init(&m_Parser, HTTP_REQUEST);
+	m_Parser.data = this;
+
+	ResetState();
+}
+
+size_t
+HttpRequest::ConsumeData(const char* InputData, size_t DataSize)
+{
+	const size_t ConsumedBytes = http_parser_execute(&m_Parser, &s_ParserSettings, InputData, DataSize);
+
+	if (m_Parser.http_errno)
+	{
+		ZEN_WARN("HTTP parser error {}", (uint32_t)m_Parser.http_errno);
+
+		// TODO: we need to kill the connection since we're most likely 
+		// out of sync and can't make progress
+	}
+
+	return ConsumedBytes;
+}
+
+void
+HttpRequest::AppendInputBytes(const char* Data, size_t Bytes)
+{
+	const size_t RemainingBufferSpace = sizeof m_HeaderBuffer + m_HeaderBuffer - m_HeaderCursor;
+
+	if (RemainingBufferSpace >= Bytes)
+	{
+		memcpy(m_HeaderCursor, Data, Bytes);
+		m_HeaderCursor += Bytes;
+
+		return;
+	}
+
+	// Terribad, but better than buffer overflow
+	TerminateConnection();
+}
+
+int
+HttpRequest::OnUrl(const char* Data, size_t Bytes)
+{
+	if (!m_Url)
+	{
+		ZEN_ASSERT_SLOW(m_UrlLength == 0);
+		m_Url = m_HeaderCursor;
+	}
+
+	AppendInputBytes(Data, Bytes);
+	m_UrlLength += Bytes;
+
+	return 0;
+}
+
+int
+HttpRequest::OnHeader(const char* Data, size_t Bytes)
+{
+	if (m_CurrentHeaderValueLength)
+	{
+		AppendCurrentHeader();
+
+		m_CurrentHeaderNameLength  = 0;
+		m_CurrentHeaderValueLength = 0;
+		m_CurrentHeaderName		   = m_HeaderCursor;
+	}
+	else if (m_CurrentHeaderName == nullptr)
+	{
+		m_CurrentHeaderName = m_HeaderCursor;
+	}
+
+	memcpy(m_HeaderCursor, Data, Bytes);
+	m_HeaderCursor += Bytes;
+	m_CurrentHeaderNameLength += Bytes;
+
+	return 0;
+}
+
+void
+HttpRequest::AppendCurrentHeader()
+{
+	std::string_view HeaderName(m_CurrentHeaderName, m_CurrentHeaderNameLength);
+	std::string_view HeaderValue(m_CurrentHeaderValue, m_CurrentHeaderValueLength);
+
+	const uint32_t HeaderHash = HashStringAsLowerDjb2(HeaderName);
+
+	if (HeaderHash == HashContentLength)
+	{
+		m_ContentLengthHeaderIndex = (int8_t)m_Headers.size();
+	}
+	else if (HeaderHash == HashAccept)
+	{
+		m_AcceptHeaderIndex = (int8_t)m_Headers.size();
+	}
+	else if (HeaderHash == HashContentType)
+	{
+		m_ContentTypeHeaderIndex = (int8_t)m_Headers.size();
+	}
+	else if (HeaderHash == HashSession)
+	{
+		m_SessionId = Oid::FromHexString(HeaderValue);
+	}
+	else if (HeaderHash == HashRequest)
+	{
+		std::from_chars(HeaderValue.data(), HeaderValue.data() + HeaderValue.size(), m_RequestId);
+	}
+
+	m_Headers.emplace_back(HeaderName, HeaderValue);
+}
+
+int
+HttpRequest::OnHeaderValue(const char* Data, size_t Bytes)
+{
+	if (m_CurrentHeaderValueLength == 0)
+	{
+		m_CurrentHeaderValue = m_HeaderCursor;
+	}
+
+	memcpy(m_HeaderCursor, Data, Bytes);
+	m_HeaderCursor += Bytes;
+	m_CurrentHeaderValueLength += Bytes;
+
+	return 0;
+}
+
+void
+HttpRequest::TerminateConnection()
+{
+	m_Connection.TerminateConnection();
+}
+
+int
+HttpRequest::OnHeadersComplete()
+{
+	if (m_CurrentHeaderValueLength)
+	{
+		AppendCurrentHeader();
+	}
+
+	if (m_ContentLengthHeaderIndex >= 0)
+	{
+		std::string_view& Value			= m_Headers[m_ContentLengthHeaderIndex].Value;
+		uint64_t		  ContentLength = 0;
+		std::from_chars(Value.data(), Value.data() + Value.size(), ContentLength);
+
+		if (ContentLength)
+		{
+			m_BodyBuffer = IoBuffer(ContentLength);
+		}
+		else
+		{
+			m_BodyBuffer = {};
+		}
+
+		m_BodyBuffer.SetContentType(ContentType());
+
+		m_BodyPosition = 0;
+	}
+
+	m_KeepAlive = !!http_should_keep_alive(&m_Parser);
+
+	return 0;
+}
+
+int
+HttpRequest::OnBody(const char* Data, size_t Bytes)
+{
+	memcpy(reinterpret_cast<uint8_t*>(m_BodyBuffer.MutableData()) + m_BodyPosition, Data, Bytes);
+	m_BodyPosition += Bytes;
+
+	if (http_body_is_final(&m_Parser))
+	{
+		if (m_BodyPosition != m_BodyBuffer.Size())
+		{
+			ZEN_WARN("Body mismatch! {} != {}", m_BodyPosition, m_BodyBuffer.Size());
+		}
+	}
+
+	return 0;
+}
+
+void
+HttpRequest::ResetState()
+{
+	m_HeaderCursor			   = m_HeaderBuffer;
+	m_CurrentHeaderName		   = nullptr;
+	m_CurrentHeaderNameLength  = 0;
+	m_CurrentHeaderValue	   = nullptr;
+	m_CurrentHeaderValueLength = 0;
+	m_CurrentHeaderName		   = nullptr;
+	m_Url					   = nullptr;
+	m_UrlLength				   = 0;
+	m_ContentLengthHeaderIndex = -1;
+	m_AcceptHeaderIndex		   = -1;
+	m_ContentTypeHeaderIndex   = -1;
+
+	m_BodyBuffer   = {};
+	m_BodyPosition = 0;
+
+	m_Headers.clear();
+}
+
+int
+HttpRequest::OnMessageBegin()
+{
+	return 0;
+}
+
+int
+HttpRequest::OnMessageComplete()
+{
+	switch (m_Parser.method)
+	{
+		case HTTP_GET:
+			m_RequestVerb = HttpVerb::kGet;
+			break;
+
+		case HTTP_POST:
+			m_RequestVerb = HttpVerb::kPost;
+			break;
+
+		case HTTP_PUT:
+			m_RequestVerb = HttpVerb::kPut;
+			break;
+
+		case HTTP_DELETE:
+			m_RequestVerb = HttpVerb::kDelete;
+			break;
+
+		case HTTP_HEAD:
+			m_RequestVerb = HttpVerb::kHead;
+			break;
+
+		case HTTP_COPY:
+			m_RequestVerb = HttpVerb::kCopy;
+			break;
+
+		case HTTP_OPTIONS:
+			m_RequestVerb = HttpVerb::kOptions;
+			break;
+	}
+
+	m_Connection.HandleRequest();
+
+	ResetState();
+
+	return 0;
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+struct HttpAcceptor
+{
+	HttpAcceptor(HttpAsioServerImpl& Server, asio::io_service& IoService, uint16_t Port)
+	: m_Server(Server)
+	, m_IoService(IoService)
+	, m_Acceptor(m_IoService, asio::ip::tcp::endpoint(asio::ip::address_v4::any(), Port))
+	{
+	}
+
+	void Start()
+	{
+		m_Acceptor.listen();
+		InitAccept();
+	}
+
+	void Stop() { m_IsStopped = true; }
+
+	void InitAccept()
+	{
+		auto				   SocketPtr = std::make_unique<asio::ip::tcp::socket>(m_IoService);
+		asio::ip::tcp::socket& SocketRef = *SocketPtr.get();
+
+		m_Acceptor.async_accept(SocketRef, [this, Socket = std::move(SocketPtr)](const asio::error_code& Ec) mutable {
+			if (Ec)
+			{
+				// TODO: Error condition - please handle and report properly
+			}
+			else
+			{
+				// New connection established, pass socket ownership into connection object
+				// and initiate request handling loop
+
+				Socket->set_option(asio::ip::tcp::no_delay(true));
+
+				HttpServerConnection* Conn = new HttpServerConnection(m_Server, std::move(Socket));
+				Conn->HandleNewRequest();
+
+				// note: the connection object is responsible for deleting itself
+			}
+
+			if (!m_IsStopped.load())
+			{
+				InitAccept();
+			}
+			else
+			{
+				m_Acceptor.close();
+			}
+		});
+	}
+
+private:
+	HttpAsioServerImpl&		m_Server;
+	asio::io_service&		m_IoService;
+	asio::ip::tcp::acceptor m_Acceptor;
+	std::atomic<bool>		m_IsStopped{false};
+};
+
+//////////////////////////////////////////////////////////////////////////
+
+HttpAsioServerRequest::HttpAsioServerRequest(asio_http::HttpRequest& Request, HttpService& Service, IoBuffer PayloadBuffer)
+: m_Request(Request)
+, m_PayloadBuffer(std::move(PayloadBuffer))
+{
+	const int PrefixLength = Service.UriPrefixLength();
+
+	std::string_view Uri = Request.Url();
+	Uri.remove_prefix(PrefixLength);
+	m_Uri = Uri;
+
+	m_Verb			= Request.RequestVerb();
+	m_ContentLength = Request.Body().Size();
+	m_ContentType	= Request.ContentType();
+
+	// It an explicit content type extension was specified then we'll use that over any
+	// Accept: header value that may be present
+	//
+	// TODO!
+
+	m_AcceptType = Request.AcceptType();
+}
+
+HttpAsioServerRequest::~HttpAsioServerRequest()
+{
+}
+
+Oid
+HttpAsioServerRequest::ParseSessionId() const
+{
+	return m_Request.SessionId();
+}
+
+uint32_t
+HttpAsioServerRequest::ParseRequestId() const
+{
+	return m_Request.RequestId();
+}
+
+IoBuffer
+HttpAsioServerRequest::ReadPayload()
+{
+	return m_PayloadBuffer;
+}
+
+void
+HttpAsioServerRequest::WriteResponse(HttpResponseCode ResponseCode)
+{
+	ZEN_ASSERT(!m_Response);
+
+	m_Response.reset(new HttpResponse(HttpContentType::kBinary));
+	std::array<IoBuffer, 0> Empty;
+
+	m_Response->InitializeForPayload((UINT16)ResponseCode, Empty);
+}
+
+void
+HttpAsioServerRequest::WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::span<IoBuffer> Blobs)
+{
+	ZEN_ASSERT(!m_Response);
+
+	m_Response.reset(new HttpResponse(ContentType));
+	m_Response->InitializeForPayload((UINT16)ResponseCode, Blobs);
+}
+
+void
+HttpAsioServerRequest::WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::u8string_view ResponseString)
+{
+	ZEN_ASSERT(!m_Response);
+	m_Response.reset(new HttpResponse(ContentType));
+
+	IoBuffer				MessageBuffer(IoBuffer::Wrap, ResponseString.data(), ResponseString.size());
+	std::array<IoBuffer, 1> SingleBufferList({MessageBuffer});
+
+	m_Response->InitializeForPayload((uint16_t)ResponseCode, SingleBufferList);
+}
+
+void
+HttpAsioServerRequest::WriteResponseAsync(std::function<void(HttpServerRequest&)>&& ContinuationHandler)
+{
+	ZEN_ASSERT(!m_Response);
+
+	// Not one bit async, innit
+	ContinuationHandler(*this);
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+HttpAsioServerImpl::HttpAsioServerImpl()
+{
+}
+
+HttpAsioServerImpl::~HttpAsioServerImpl()
+{
+}
+
+void
+HttpAsioServerImpl::Start(uint16_t Port, int ThreadCount)
+{
+	ZEN_ASSERT(ThreadCount > 0);
+
+	m_Acceptor.reset(new asio_http::HttpAcceptor(*this, m_IoService, Port));
+	m_Acceptor->Start();
+
+	for (int i = 0; i < ThreadCount; ++i)
+	{
+		m_ThreadPool.emplace_back([this, Index = i + 1] {
+			SetCurrentThreadName("asio worker {}"_format(Index));
+
+			try
+			{
+				m_IoService.run();
+			}
+			catch (std::exception& e)
+			{
+				ZEN_ERROR("Exception caught in asio event loop: '{}'", e.what());
+			}
+		});
+	}
+}
+
+void
+HttpAsioServerImpl::Stop()
+{
+	m_Acceptor->Stop();
+	m_IoService.stop();
+	for (auto& Thread : m_ThreadPool)
+	{
+		Thread.join();
+	}
+}
+
+void
+HttpAsioServerImpl::RegisterService(const char* InUrlPath, HttpService& Service)
+{
+	std::string_view UrlPath(InUrlPath);
+	Service.SetUriPrefixLength(UrlPath.size());
+
+	RwLock::ExclusiveLockScope _(m_Lock);
+	m_UriHandlers.push_back({std::string(UrlPath), &Service});
+}
+
+HttpService*
+HttpAsioServerImpl::RouteRequest(std::string_view Url)
+{
+	RwLock::SharedLockScope _(m_Lock);
+
+	for (const ServiceEntry& SvcEntry : m_UriHandlers)
+	{
+		const std::string& SvcUrl = SvcEntry.ServiceUrlPath;
+		if (Url.compare(0, SvcUrl.size(), SvcUrl) == 0)
+		{
+			return SvcEntry.Service;
+		}
+	}
+
+	return nullptr;
+}
+
+}  // namespace zen::asio_http
+
+//////////////////////////////////////////////////////////////////////////
+
+namespace zen {
+HttpAsioServer::HttpAsioServer() : m_Impl(std::make_unique<asio_http::HttpAsioServerImpl>())
+{
+}
+
+HttpAsioServer::~HttpAsioServer()
+{
+	m_Impl->Stop();
+}
+
+void
+HttpAsioServer::RegisterService(HttpService& Service)
+{
+	m_Impl->RegisterService(Service.BaseUri(), Service);
+}
+
+void
+HttpAsioServer::Initialize(int BasePort)
+{
+	m_BasePort = BasePort;
+
+	m_Impl->Start(gsl::narrow<uint16_t>(m_BasePort), Max(std::thread::hardware_concurrency(), 8u));
+}
+
+void
+HttpAsioServer::Run(bool IsInteractive)
+{
+	const bool TestMode = !IsInteractive;
+
+	if (TestMode == false)
+	{
+		zen::logging::ConsoleLog().info("Zen Server running (asio HTTP). Press ESC or Q to quit");
+	}
+
+	do
+	{
+		int WaitTimeout = -1;
+
+		if (!TestMode)
+		{
+			WaitTimeout = 1000;
+		}
+
+		if (!TestMode && _kbhit() != 0)
+		{
+			char c = (char)_getch();
+
+			if (c == 27 || c == 'Q' || c == 'q')
+			{
+				RequestApplicationExit(0);
+			}
+		}
+
+		m_ShutdownEvent.Wait(WaitTimeout);
+	} while (!IsApplicationExitRequested());
+}
+
+void
+HttpAsioServer::RequestExit()
+{
+	m_ShutdownEvent.Set();
+}
+
+}  // namespace zen
diff --git a/zenhttp/httpuws.h b/zenhttp/httpasio.h
index 5e300202f..08834ba21 100644
--- a/zenhttp/httpuws.h
+++ b/zenhttp/httpasio.h
@@ -2,17 +2,24 @@
 
 #pragma once
 
+#include <zencore/thread.h>
 #include <zenhttp/httpserver.h>
 
-#include <zencore/thread.h>
+#include <memory>
 
 namespace zen {
 
-class HttpUwsServer : public HttpServer
+namespace asio_http {
+	struct HttpServerConnection;
+	struct HttpAcceptor;
+	struct HttpAsioServerImpl;
+}  // namespace asio_http
+
+class HttpAsioServer : public HttpServer
 {
 public:
-	HttpUwsServer();
-	~HttpUwsServer();
+	HttpAsioServer();
+	~HttpAsioServer();
 
 	virtual void RegisterService(HttpService& Service) override;
 	virtual void Initialize(int BasePort) override;
@@ -22,6 +29,8 @@ public:
 private:
 	Event m_ShutdownEvent;
 	int	  m_BasePort = 0;
+
+	std::unique_ptr<asio_http::HttpAsioServerImpl> m_Impl;
 };
 
-}  // namespace zen
\ No newline at end of file
+}  // namespace zen
diff --git a/zenhttp/httpserver.cpp b/zenhttp/httpserver.cpp
index 69974ca06..150054c30 100644
--- a/zenhttp/httpserver.cpp
+++ b/zenhttp/httpserver.cpp
@@ -2,9 +2,9 @@
 
 #include <zenhttp/httpserver.h>
 
+#include "httpasio.h"
 #include "httpnull.h"
 #include "httpsys.h"
-#include "httpuws.h"
 
 #include <zencore/compactbinary.h>
 #include <zencore/compactbinarypackage.h>
@@ -565,16 +565,56 @@ HttpRequestRouter::HandleRequest(zen::HttpServerRequest& Request)
 
 //////////////////////////////////////////////////////////////////////////
 
+enum class HttpServerClass
+{
+	kHttpAsio,
+	kHttpSys,
+	kHttpNull
+};
+
 Ref<HttpServer>
-CreateHttpServer()
+CreateHttpServer(std::string_view ServerClass)
 {
-#if 0
-	return new HttpUwsServer;
+	using namespace std::literals;
+
+#if 1
+	HttpServerClass Class = HttpServerClass::kHttpAsio;
 #elif ZEN_WITH_HTTPSYS
-	return new HttpSysServer(std::thread::hardware_concurrency(), /* background worker threads */ 16);
+	HttpServerClass Class = HttpServerClass::kHttpSys;
 #else
-	return new HttpNullServer;
+	HttpServerClass Class = HttpServerClass::kHttpNull;
+#endif
+
+	if (ServerClass == "asio"sv)
+	{
+		Class = HttpServerClass::kHttpAsio;
+	}
+	else if (ServerClass == "httpsys"sv)
+	{
+		Class = HttpServerClass::kHttpSys;
+	}
+	else if (ServerClass == "null"sv)
+	{
+		Class = HttpServerClass::kHttpNull;
+	}
+
+	switch (Class)
+	{
+		default:
+		case HttpServerClass::kHttpAsio:
+			ZEN_INFO("using asio HTTP server implementation");
+			return new HttpAsioServer();
+
+#if ZEN_WITH_HTTPSYS
+		case HttpServerClass::kHttpSys:
+			ZEN_INFO("using http.sys server implementation");
+			return new HttpSysServer(std::thread::hardware_concurrency(), /* background worker threads */ 16);
 #endif
+
+		case HttpServerClass::kHttpNull:
+			ZEN_INFO("using null HTTP server implementation");
+			return new HttpNullServer;
+	}
 }
 
 //////////////////////////////////////////////////////////////////////////
diff --git a/zenhttp/httpsys.cpp b/zenhttp/httpsys.cpp
index f550f1f4c..0a9341d0c 100644
--- a/zenhttp/httpsys.cpp
+++ b/zenhttp/httpsys.cpp
@@ -194,9 +194,11 @@ public:
 	HttpSysServerRequest(const HttpSysServerRequest&) = delete;
 	HttpSysServerRequest& operator=(const HttpSysServerRequest&) = delete;
 
-	HttpSysTransaction&	   m_HttpTx;
-	HttpSysRequestHandler* m_NextCompletionHandler = nullptr;
-	IoBuffer			   m_PayloadBuffer;
+	HttpSysTransaction&			 m_HttpTx;
+	HttpSysRequestHandler*		 m_NextCompletionHandler = nullptr;
+	IoBuffer					 m_PayloadBuffer;
+	ExtendableStringBuilder<128> m_UriUtf8;
+	ExtendableStringBuilder<128> m_QueryStringUtf8;
 };
 
 /** HTTP transaction
@@ -1252,6 +1254,8 @@ HttpSysServerRequest::HttpSysServerRequest(HttpSysTransaction& Tx, HttpService&
 		m_UriUtf8.Reset();
 	}
 
+	m_Uri = std::string_view(m_UriUtf8);
+
 	if (uint16_t QueryStringLength = HttpRequestPtr->CookedUrl.QueryStringLength)
 	{
 		--QueryStringLength;  // We skip the leading question mark
@@ -1263,6 +1267,8 @@ HttpSysServerRequest::HttpSysServerRequest(HttpSysTransaction& Tx, HttpService&
 		m_QueryStringUtf8.Reset();
 	}
 
+	m_QueryString = std::string_view(m_QueryStringUtf8);
+
 	m_Verb			= TranslateHttpVerb(HttpRequestPtr->Verb);
 	m_ContentLength = GetContentLength(HttpRequestPtr);
 	m_ContentType	= GetContentType(HttpRequestPtr);
diff --git a/zenhttp/httpuws.cpp b/zenhttp/httpuws.cpp
deleted file mode 100644
index 2a6950532..000000000
--- a/zenhttp/httpuws.cpp
+++ /dev/null
@@ -1,94 +0,0 @@
-// Copyright Epic Games, Inc. All Rights Reserved.
-
-#include "httpuws.h"
-
-#pragma warning(push)
-#pragma warning(disable : 4244 4324 4267 4458 4706)
-#include <uwebsockets/App.h>
-#pragma warning(pop)
-
-#include <conio.h>
-#include <zencore/logging.h>
-
-#if ZEN_PLATFORM_WINDOWS
-#	pragma comment(lib, "Iphlpapi.lib")
-#	pragma comment(lib, "userenv.lib")
-#endif
-
-namespace zen {
-
-HttpUwsServer::HttpUwsServer()
-{
-}
-
-HttpUwsServer::~HttpUwsServer()
-{
-}
-
-void
-HttpUwsServer::RegisterService(HttpService& Service)
-{
-	ZEN_UNUSED(Service);
-}
-
-void
-HttpUwsServer::Initialize(int BasePort)
-{
-	m_BasePort = BasePort;
-}
-
-void
-HttpUwsServer::Run(bool IsInteractive)
-{
-	const bool TestMode = !IsInteractive;
-
-	if (TestMode == false)
-	{
-		zen::logging::ConsoleLog().info("Zen Server running (uWS HTTP). Press ESC or Q to quit");
-	}
-
-	::uWS::App()
-		.any("/*",
-			 [](uWS::HttpResponse<false>* res, uWS::HttpRequest* req) {
-				 res->onData([=](std::string_view Data, bool fin) {
-					 ZEN_UNUSED(Data);
-					 if (fin)
-						 res->end("Hello world!");
-				 });
-
-				 res->onAborted([&] {});
-				 ZEN_UNUSED(req);
-			 })
-		.listen(m_BasePort, [](auto* listen_socket) { ZEN_UNUSED(listen_socket); })
-		.run();
-
-	do
-	{
-		int WaitTimeout = -1;
-
-		if (!TestMode)
-		{
-			WaitTimeout = 1000;
-		}
-
-		if (!TestMode && _kbhit() != 0)
-		{
-			char c = (char)_getch();
-
-			if (c == 27 || c == 'Q' || c == 'q')
-			{
-				RequestApplicationExit(0);
-			}
-		}
-
-		m_ShutdownEvent.Wait(WaitTimeout);
-	} while (!IsApplicationExitRequested());
-}
-
-void
-HttpUwsServer::RequestExit()
-{
-	m_ShutdownEvent.Set();
-}
-
-}  // namespace zen
diff --git a/zenhttp/include/zenhttp/httpserver.h b/zenhttp/include/zenhttp/httpserver.h
index 3e6608f11..55bd08a8e 100644
--- a/zenhttp/include/zenhttp/httpserver.h
+++ b/zenhttp/include/zenhttp/httpserver.h
@@ -32,8 +32,8 @@ public:
 
 	// Synchronous operations
 
-	[[nodiscard]] inline std::string_view RelativeUri() const { return m_UriUtf8; }	 // Returns URI without service prefix
-	[[nodiscard]] inline std::string_view QueryString() const { return m_QueryStringUtf8; }
+	[[nodiscard]] inline std::string_view RelativeUri() const { return m_Uri; }	 // Returns URI without service prefix
+	[[nodiscard]] inline std::string_view QueryString() const { return m_QueryString; }
 
 	struct QueryParams
 	{
@@ -108,15 +108,15 @@ protected:
 		kHaveSessionId = 1 << 3,
 	};
 
-	mutable uint32_t			 m_Flags		 = 0;
-	HttpVerb					 m_Verb			 = HttpVerb::kGet;
-	HttpContentType				 m_ContentType	 = HttpContentType::kBinary;
-	HttpContentType				 m_AcceptType	 = HttpContentType::kUnknownContentType;
-	uint64_t					 m_ContentLength = ~0ull;
-	ExtendableStringBuilder<128> m_UriUtf8;
-	ExtendableStringBuilder<128> m_QueryStringUtf8;
-	mutable uint32_t			 m_RequestId = ~uint32_t(0);
-	mutable Oid					 m_SessionId = Oid::Zero;
+	mutable uint32_t m_Flags		 = 0;
+	HttpVerb		 m_Verb			 = HttpVerb::kGet;
+	HttpContentType	 m_ContentType	 = HttpContentType::kBinary;
+	HttpContentType	 m_AcceptType	 = HttpContentType::kUnknownContentType;
+	uint64_t		 m_ContentLength = ~0ull;
+	std::string_view m_Uri;
+	std::string_view m_QueryString;
+	mutable uint32_t m_RequestId = ~uint32_t(0);
+	mutable Oid		 m_SessionId = Oid::Zero;
 
 	inline void SetIsHandled() { m_Flags |= kIsHandled; }
 
@@ -173,7 +173,7 @@ public:
 	virtual void RequestExit()						   = 0;
 };
 
-Ref<HttpServer> CreateHttpServer();
+Ref<HttpServer> CreateHttpServer(std::string_view ServerClass);
 
 //////////////////////////////////////////////////////////////////////////
 
diff --git a/zenhttp/xmake.lua b/zenhttp/xmake.lua
index 65d5f08ea..fff4fb526 100644
--- a/zenhttp/xmake.lua
+++ b/zenhttp/xmake.lua
@@ -3,5 +3,5 @@ target('zenhttp')
     add_files("**.cpp")
     add_includedirs("include", {public=true})
     add_deps("zencore")
-    add_packages("vcpkg::gsl-lite", "vcpkg::uwebsockets", "vcpkg::usockets", "vcpkg::libuv")
+    add_packages("vcpkg::gsl-lite")
     add_options("httpsys")
\ No newline at end of file
diff --git a/zenhttp/zenhttp.vcxproj b/zenhttp/zenhttp.vcxproj
index 1fc64bfc2..c86a41283 100644
--- a/zenhttp/zenhttp.vcxproj
+++ b/zenhttp/zenhttp.vcxproj
@@ -93,20 +93,20 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="httpasio.cpp" />
     <ClCompile Include="httpclient.cpp" />
     <ClCompile Include="httpnull.cpp" />
     <ClCompile Include="httpserver.cpp" />
     <ClCompile Include="httpshared.cpp" />
     <ClCompile Include="httpsys.cpp" />
-    <ClCompile Include="httpuws.cpp" />
     <ClCompile Include="iothreadpool.cpp" />
     <ClCompile Include="workthreadpool.cpp" />
     <ClCompile Include="zenhttp.cpp" />
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="httpasio.h" />
     <ClInclude Include="httpnull.h" />
     <ClInclude Include="httpsys.h" />
-    <ClInclude Include="httpuws.h" />
     <ClInclude Include="include\zenhttp\httpclient.h" />
     <ClInclude Include="include\zenhttp\httpcommon.h" />
     <ClInclude Include="include\zenhttp\httpserver.h" />
diff --git a/zenhttp/zenhttp.vcxproj.filters b/zenhttp/zenhttp.vcxproj.filters
index e57e7a712..ffc98b1c6 100644
--- a/zenhttp/zenhttp.vcxproj.filters
+++ b/zenhttp/zenhttp.vcxproj.filters
@@ -6,10 +6,10 @@
     <ClCompile Include="httpsys.cpp" />
     <ClCompile Include="iothreadpool.cpp" />
     <ClCompile Include="httpnull.cpp" />
-    <ClCompile Include="httpuws.cpp" />
     <ClCompile Include="httpshared.cpp" />
     <ClCompile Include="zenhttp.cpp" />
     <ClCompile Include="workthreadpool.cpp" />
+    <ClCompile Include="httpasio.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="include\zenhttp\httpclient.h" />
@@ -18,10 +18,10 @@
     <ClInclude Include="iothreadpool.h" />
     <ClInclude Include="include\zenhttp\zenhttp.h" />
     <ClInclude Include="httpnull.h" />
-    <ClInclude Include="httpuws.h" />
     <ClInclude Include="include\zenhttp\httpcommon.h" />
     <ClInclude Include="include\zenhttp\httpshared.h" />
     <ClInclude Include="workthreadpool.h" />
+    <ClInclude Include="httpasio.h" />
   </ItemGroup>
   <ItemGroup>
     <None Include="xmake.lua" />
diff --git a/zenserver/config.cpp b/zenserver/config.cpp
index df3259542..8d7254ae1 100644
--- a/zenserver/config.cpp
+++ b/zenserver/config.cpp
@@ -81,6 +81,12 @@ ParseUpstreamCachePolicy(std::string_view Options)
 void
 ParseGlobalCliOptions(int argc, char* argv[], ZenServerOptions& GlobalOptions, ZenServiceConfig& ServiceConfig)
 {
+#if ZEN_WITH_HTTPSYS
+	const char* DefaultHttp = "httpsys";
+#else
+	const char* DefaultHttp = "asio";
+#endif
+
 	cxxopts::Options options("zenserver", "Zen Server");
 	options.add_options()("dedicated",
 						  "Enable dedicated server mode",
@@ -118,6 +124,13 @@ ParseGlobalCliOptions(int argc, char* argv[], ZenServerOptions& GlobalOptions, Z
 #endif
 
 	options.add_option("network",
+					   "",
+					   "http",
+					   "Select HTTP server implementation (asio|httpsys|null)",
+					   cxxopts::value<std::string>(GlobalOptions.HttpServerClass)->default_value(DefaultHttp),
+					   "<http class>");
+
+	options.add_option("network",
 					   "p",
 					   "port",
 					   "Select HTTP port",
diff --git a/zenserver/config.h b/zenserver/config.h
index 405e22739..eaafc31bb 100644
--- a/zenserver/config.h
+++ b/zenserver/config.h
@@ -18,7 +18,8 @@ struct ZenServerOptions
 	std::string			  LogId;					 // Id for tagging log output
 	std::filesystem::path DataDir;					 // Root directory for state (used for testing)
 	std::filesystem::path ContentDir;				 // Root directory for serving frontend content (experimental)
-	std::filesystem::path AbsLogFile;
+	std::string			  HttpServerClass;			 // Choice of HTTP server implementation
+	std::filesystem::path AbsLogFile;				 // Absolute path to main log file
 };
 
 struct ZenUpstreamJupiterConfig
diff --git a/zenserver/xmake.lua b/zenserver/xmake.lua
index fb1ba651d..bba9b6ba5 100644
--- a/zenserver/xmake.lua
+++ b/zenserver/xmake.lua
@@ -26,7 +26,7 @@ target("zenserver")
         "vcpkg::lua",
         "vcpkg::asio",
         "vcpkg::json11",
-        "vcpkg::uwebsockets", "vcpkg::usockets", "vcpkg::libuv"
+        "vcpkg::http-parser"
     )
 
     add_packages(
diff --git a/zenserver/zenserver.cpp b/zenserver/zenserver.cpp
index 18c59636d..1fddec437 100644
--- a/zenserver/zenserver.cpp
+++ b/zenserver/zenserver.cpp
@@ -108,7 +108,7 @@ using namespace std::literals;
 class ZenServer : public IHttpStatusProvider
 {
 public:
-	void Initialize(ZenServiceConfig& ServiceConfig, int BasePort, int ParentPid, ZenServerState::ZenServerEntry* ServerEntry)
+	void Initialize(ZenServiceConfig& ServiceConfig, std::string_view HttpServerClass, int BasePort, int ParentPid, ZenServerState::ZenServerEntry* ServerEntry)
 	{
 		using namespace fmt::literals;
 
@@ -146,7 +146,7 @@ public:
 
 		// Ok so now we're configured, let's kick things off
 
-		m_Http = zen::CreateHttpServer();
+		m_Http = zen::CreateHttpServer(HttpServerClass);
 		m_Http->Initialize(BasePort);
 		m_Http->RegisterService(m_HealthService);
 		m_Http->RegisterService(m_StatsService);
@@ -636,7 +636,7 @@ ZenWindowsService::Run()
 		Server.SetContentRoot(GlobalOptions.ContentDir);
 		Server.SetTestMode(GlobalOptions.IsTest);
 		Server.SetDedicatedMode(GlobalOptions.IsDedicated);
-		Server.Initialize(ServiceConfig, GlobalOptions.BasePort, GlobalOptions.OwnerPid, Entry);
+		Server.Initialize(ServiceConfig, GlobalOptions.HttpServerClass, GlobalOptions.BasePort, GlobalOptions.OwnerPid, Entry);
 
 		// Monitor shutdown signals