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

119 lines
3.7 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 "llvm/Support/YAMLParser.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 {
public:
JSONOutput(llvm::raw_ostream &Outs, llvm::raw_ostream &Logs,
llvm::raw_ostream *InputMirror = nullptr, bool Pretty = false)
: Outs(Outs), Logs(Logs), InputMirror(InputMirror), Pretty(Pretty) {}
/// Emit a JSONRPC message.
void writeMessage(const json::Expr &Result);
/// Write to the logging stream.
/// No newline is implicitly added. (TODO: we should fix this!)
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);
private:
llvm::raw_ostream &Outs;
llvm::raw_ostream &Logs;
llvm::raw_ostream *InputMirror;
bool Pretty;
std::mutex StreamMutex;
};
/// Context object passed to handlers to allow replies.
class RequestContext {
public:
RequestContext(JSONOutput &Out, StringRef Method,
llvm::Optional<json::Expr> ID)
: Out(Out), ID(std::move(ID)),
Tracer(llvm::make_unique<trace::Span>(Method)) {
if (this->ID)
SPAN_ATTACH(tracer(), "ID", *this->ID);
}
/// Sends a successful reply.
void reply(json::Expr &&Result);
/// Sends an error response to the client, and logs it.
void replyError(ErrorCode code, const llvm::StringRef &Message);
/// Sends a request to the client.
void call(llvm::StringRef Method, json::Expr &&Params);
trace::Span &tracer() { return *Tracer; }
private:
JSONOutput &Out;
llvm::Optional<json::Expr> ID;
std::unique_ptr<trace::Span> Tracer;
};
/// 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(RequestContext, llvm::yaml::MappingNode *)>;
/// 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(StringRef Content, JSONOutput &Out) const;
private:
llvm::StringMap<Handler> Handlers;
Handler UnknownHandler;
};
/// 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,
JSONRPCDispatcher &Dispatcher, bool &IsDone);
} // namespace clangd
} // namespace clang
#endif