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

86 lines
2.6 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 "clang/Basic/LLVM.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/YAMLParser.h"
#include <mutex>
namespace clang {
namespace clangd {
/// Encapsulates output and logs streams and provides thread-safe access to
/// them.
class JSONOutput {
public:
JSONOutput(llvm::raw_ostream &Outs, llvm::raw_ostream &Logs)
: Outs(Outs), Logs(Logs) {}
/// Emit a JSONRPC message.
void writeMessage(const Twine &Message);
/// Write to the logging stream.
void log(const Twine &Message);
private:
llvm::raw_ostream &Outs;
llvm::raw_ostream &Logs;
std::mutex StreamMutex;
};
/// Callback for messages sent to the server, called by the JSONRPCDispatcher.
class Handler {
public:
Handler(JSONOutput &Output) : Output(Output) {}
virtual ~Handler() = default;
/// Called when the server receives a method call. This is supposed to return
/// a result on Outs. The default implementation returns an "unknown method"
/// error to the client and logs a warning.
virtual void handleMethod(llvm::yaml::MappingNode *Params, StringRef ID);
/// Called when the server receives a notification. No result should be
/// written to Outs. The default implemetation logs a warning.
virtual void handleNotification(llvm::yaml::MappingNode *Params);
protected:
JSONOutput &Output;
/// Helper to write a JSONRPC result to Output.
void writeMessage(const Twine &Message) { Output.writeMessage(Message); }
};
/// Main JSONRPC entry point. This parses the JSONRPC "header" and calls the
/// registered Handler for the method received.
class JSONRPCDispatcher {
public:
/// Create a new JSONRPCDispatcher. UnknownHandler is called when an unknown
/// method is received.
JSONRPCDispatcher(std::unique_ptr<Handler> UnknownHandler)
: UnknownHandler(std::move(UnknownHandler)) {}
/// Registers a Handler for the specified Method.
void registerHandler(StringRef Method, std::unique_ptr<Handler> H);
/// Parses a JSONRPC message and calls the Handler for it.
bool call(StringRef Content) const;
private:
llvm::StringMap<std::unique_ptr<Handler>> Handlers;
std::unique_ptr<Handler> UnknownHandler;
};
} // namespace clangd
} // namespace clang
#endif