1 files changed, 45 insertions, 22 deletions

diff --git a/clang-tools-extra/clangd/JSONRPCDispatcher.h b/clang-tools-extra/clangd/JSONRPCDispatcher.h
index 43c466f7014..b223ceb5f45 100644
--- a/clang-tools-extra/clangd/JSONRPCDispatcher.h
+++ b/clang-tools-extra/clangd/JSONRPCDispatcher.h
@@ -14,7 +14,6 @@
 #include "Logger.h"
 #include "Protocol.h"
 #include "Trace.h"
-#include "Transport.h"
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
@@ -25,19 +24,37 @@
 namespace clang {
 namespace clangd {
 
-// Logs to an output stream, such as stderr.
-// FIXME: Rename to StreamLogger or such, and move to Logger.h.
+/// Encapsulates output and logs streams and provides thread-safe access to
+/// them.
 class JSONOutput : public Logger {
+  // FIXME(ibiryukov): figure out if we can shrink the public interface of
+  // JSONOutput now that we pass Context everywhere.
 public:
-  JSONOutput(llvm::raw_ostream &Logs, Logger::Level MinLevel)
-      : MinLevel(MinLevel), Logs(Logs) {}
+  JSONOutput(llvm::raw_ostream &Outs, llvm::raw_ostream &Logs,
+             Logger::Level MinLevel, llvm::raw_ostream *InputMirror = nullptr,
+             bool Pretty = false)
+      : Pretty(Pretty), MinLevel(MinLevel), Outs(Outs), Logs(Logs),
+        InputMirror(InputMirror) {}
+
+  /// Emit a JSONRPC message.
+  void writeMessage(const llvm::json::Value &Result);
 
   /// Write a line to the logging stream.
   void log(Level, const llvm::formatv_object_base &Message) override;
 
+  /// Mirror \p Message into InputMirror stream. Does nothing if InputMirror is
+  /// null.
+  /// Unlike other methods of JSONOutput, mirrorInput is not thread-safe.
+  void mirrorInput(const Twine &Message);
+
+  // Whether output should be pretty-printed.
+  const bool Pretty;
+
 private:
   Logger::Level MinLevel;
+  llvm::raw_ostream &Outs;
   llvm::raw_ostream &Logs;
+  llvm::raw_ostream *InputMirror;
 
   std::mutex StreamMutex;
 };
@@ -64,15 +81,14 @@ void call(llvm::StringRef Method, llvm::json::Value &&Params);
 ///
 /// The `$/cancelRequest` notification is handled by the dispatcher itself.
 /// It marks the matching request as cancelled, if it's still running.
-class JSONRPCDispatcher : private Transport::MessageHandler {
+class JSONRPCDispatcher {
 public:
   /// A handler responds to requests for a particular method name.
-  /// It returns false if the server should now shut down.
   ///
   /// JSONRPCDispatcher will mark the handler's context as cancelled if a
   /// matching cancellation request is received. Handlers are encouraged to
   /// check for cancellation and fail quickly in this case.
-  using Handler = std::function<bool(const llvm::json::Value &)>;
+  using Handler = std::function<void(const llvm::json::Value &)>;
 
   /// Create a new JSONRPCDispatcher. UnknownHandler is called when an unknown
   /// method is received.
@@ -81,22 +97,10 @@ public:
   /// Registers a Handler for the specified Method.
   void registerHandler(StringRef Method, Handler H);
 
-  /// Parses input queries from LSP client (coming from \p In) and runs call
-  /// method for each query.
-  ///
-  /// Input stream(\p In) must be opened in binary mode to avoid
-  /// preliminary replacements of \r\n with \n. We use C-style FILE* for reading
-  /// as std::istream has unclear interaction with signals, which are sent by
-  /// debuggers on some OSs.
-  llvm::Error runLanguageServerLoop(Transport &);
+  /// Parses a JSONRPC message and calls the Handler for it.
+  bool call(const llvm::json::Value &Message, JSONOutput &Out);
 
 private:
-  bool onReply(llvm::json::Value ID,
-               llvm::Expected<llvm::json::Value> Result) override;
-  bool onNotify(llvm::StringRef Method, llvm::json::Value Message) override;
-  bool onCall(llvm::StringRef Method, llvm::json::Value Message,
-              llvm::json::Value ID) override;
-
   // Tracking cancellations needs a mutex: handlers may finish on a different
   // thread, and that's when we clean up entries in the map.
   mutable std::mutex RequestCancelersMutex;
@@ -109,6 +113,25 @@ private:
   Handler UnknownHandler;
 };
 
+/// Controls the way JSON-RPC messages are encoded (both input and output).
+enum JSONStreamStyle {
+  /// Encoding per the LSP specification, with mandatory Content-Length header.
+  Standard,
+  /// Messages are delimited by a '---' line. Comment lines start with #.
+  Delimited
+};
+
+/// Parses input queries from LSP client (coming from \p In) and runs call
+/// method of \p Dispatcher for each query.
+/// After handling each query checks if \p IsDone is set true and exits the loop
+/// if it is.
+/// Input stream(\p In) must be opened in binary mode to avoid preliminary
+/// replacements of \r\n with \n.
+/// We use C-style FILE* for reading as std::istream has unclear interaction
+/// with signals, which are sent by debuggers on some OSs.
+void runLanguageServerLoop(std::FILE *In, JSONOutput &Out,
+                           JSONStreamStyle InputStyle,
+                           JSONRPCDispatcher &Dispatcher, bool &IsDone);
 } // namespace clangd
 } // namespace clang