llvm-project/clang-tools-extra/clangd/JSONRPCDispatcher.h

113 lines
3.8 KiB
C++

//===--- 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 "JSONExpr.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 <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,
llvm::raw_ostream *InputMirror = nullptr, bool Pretty = false)
: Pretty(Pretty), Outs(Outs), Logs(Logs), InputMirror(InputMirror) {}
/// Emit a JSONRPC message.
void writeMessage(const json::Expr &Result);
/// Write a line to the logging stream.
void log(const Twine &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:
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(json::Expr &&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);
/// Sends a request to the client.
/// Current context must derive from JSONRPCDispatcher::Handler.
void call(llvm::StringRef Method, json::Expr &&Params);
/// Main JSONRPC entry point. This parses the JSONRPC "header" and calls the
/// registered Handler for the method received.
class JSONRPCDispatcher {
public:
// A handler responds to requests for a particular method name.
using Handler = std::function<void(const json::Expr &)>;
/// Create a new JSONRPCDispatcher. UnknownHandler is called when an unknown
/// method is received.
JSONRPCDispatcher(Handler UnknownHandler)
: UnknownHandler(std::move(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 json::Expr &Message, JSONOutput &Out) const;
private:
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.
void runLanguageServerLoop(std::istream &In, JSONOutput &Out,
JSONStreamStyle InputStyle,
JSONRPCDispatcher &Dispatcher, bool &IsDone);
} // namespace clangd
} // namespace clang
#endif