| //===--- JSONRPCDispatcher.h - Main JSON parser entry point -----*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_JSONRPCDISPATCHER_H |
| #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_JSONRPCDISPATCHER_H |
| |
| #include "Cancellation.h" |
| #include "Logger.h" |
| #include "Protocol.h" |
| #include "Trace.h" |
| #include "clang/Basic/LLVM.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringMap.h" |
| #include "llvm/Support/JSON.h" |
| #include <iosfwd> |
| #include <mutex> |
| |
| namespace clang { |
| namespace clangd { |
| |
| /// 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 &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; |
| }; |
| |
| /// Sends a successful reply. |
| /// Current context must derive from JSONRPCDispatcher::Handler. |
| void reply(llvm::json::Value &&Result); |
| /// Sends an error response to the client, and logs it. |
| /// Current context must derive from JSONRPCDispatcher::Handler. |
| void replyError(ErrorCode Code, const llvm::StringRef &Message); |
| /// Implements ErrorCode and message extraction from a given llvm::Error. It |
| /// fetches the related message from error's message method. If error doesn't |
| /// match any known errors, uses ErrorCode::InvalidParams for the error. |
| void replyError(llvm::Error E); |
| /// Returns the request-id of the current request. Should not be used directly |
| /// for replying to requests, use the above mentioned methods for that case. |
| const llvm::json::Value *getRequestId(); |
| /// Sends a request to the client. |
| /// Current context must derive from JSONRPCDispatcher::Handler. |
| void call(llvm::StringRef Method, llvm::json::Value &&Params); |
| |
| /// Main JSONRPC entry point. This parses the JSONRPC "header" and calls the |
| /// registered Handler for the method received. |
| /// |
| /// The `$/cancelRequest` notification is handled by the dispatcher itself. |
| /// It marks the matching request as cancelled, if it's still running. |
| class JSONRPCDispatcher { |
| public: |
| /// A handler responds to requests for a particular method name. |
| /// |
| /// 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<void(const llvm::json::Value &)>; |
| |
| /// Create a new JSONRPCDispatcher. UnknownHandler is called when an unknown |
| /// method is received. |
| JSONRPCDispatcher(Handler UnknownHandler); |
| |
| /// Registers a Handler for the specified Method. |
| void registerHandler(StringRef Method, Handler H); |
| |
| /// Parses a JSONRPC message and calls the Handler for it. |
| bool call(const llvm::json::Value &Message, JSONOutput &Out); |
| |
| private: |
| // 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; |
| llvm::StringMap<std::pair<Canceler, unsigned>> RequestCancelers; |
| unsigned NextRequestCookie = 0; |
| Context cancelableRequestContext(const llvm::json::Value &ID); |
| void cancelRequest(const llvm::json::Value &ID); |
| |
| llvm::StringMap<Handler> Handlers; |
| 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 |
| |
| #endif |