cmake-server: Bare-bones server implementation

Adds a bare-bones cmake-server implementation and makes it possible
to start that with "cmake -E server".

Communication happens via stdin/stdout for now.

Protocol is based on Json objects surrounded by magic strings
("[== CMake Server ==[" and "]== CMake Server ==]"), which simplifies
Json parsing significantly.

This patch also defines an interface used to implement different
versions of the protocol spoken by the server, but does not include
any protocol implementaiton.

1 files changed, 85 insertions, 0 deletions

diff --git a/Source/cmServer.h b/Source/cmServer.h
new file mode 100644
index 0000000000..0ef1e17e51
--- /dev/null
+++ b/Source/cmServer.h
@@ -0,0 +1,85 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2015 Stephen Kelly <steveire@gmail.com>
+  Copyright 2016 Tobias Hunger <tobias.hunger@qt.io>
+
+  Distributed under the OSI-approved BSD License (the "License");
+  see accompanying file Copyright.txt for details.
+
+  This software is distributed WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the License for more information.
+============================================================================*/
+
+#pragma once
+
+#include "cmListFileCache.h"
+#include "cmState.h"
+
+#if defined(CMAKE_BUILD_WITH_CMAKE)
+#include "cm_jsoncpp_value.h"
+#include "cm_uv.h"
+#endif
+
+#include <string>
+#include <vector>
+
+class cmServerProtocol;
+class cmServerRequest;
+class cmServerResponse;
+
+class cmServer
+{
+public:
+  cmServer();
+  ~cmServer();
+
+  void Serve();
+
+  // for callbacks:
+  void PopOne();
+  void handleData(std::string const& data);
+
+private:
+  void RegisterProtocol(cmServerProtocol* protocol);
+
+  // Handle requests:
+  cmServerResponse SetProtocolVersion(const cmServerRequest& request);
+
+  void PrintHello() const;
+
+  // Write responses:
+  void WriteProgress(const cmServerRequest& request, int min, int current,
+                     int max, const std::string& message) const;
+  void WriteResponse(const cmServerResponse& response) const;
+  void WriteParseError(const std::string& message) const;
+
+  void WriteJsonObject(Json::Value const& jsonValue) const;
+
+  static cmServerProtocol* FindMatchingProtocol(
+    const std::vector<cmServerProtocol*>& protocols, int major, int minor);
+
+  cmServerProtocol* Protocol = nullptr;
+  std::vector<cmServerProtocol*> SupportedProtocols;
+  std::vector<std::string> Queue;
+
+  std::string DataBuffer;
+  std::string JsonData;
+
+  uv_loop_t* Loop = nullptr;
+
+  typedef union
+  {
+    uv_tty_t tty;
+    uv_pipe_t pipe;
+  } InOutUnion;
+
+  InOutUnion Input;
+  InOutUnion Output;
+  uv_stream_t* InputStream = nullptr;
+  uv_stream_t* OutputStream = nullptr;
+
+  mutable bool Writing = false;
+
+  friend class cmServerRequest;
+};