source: tools/langserver/src/main.cpp@ ef1da0e2

#include <cstdio>

#include <iostream>
#include <string>
#include <vector>

#include <unistd.h>

#include "json.hpp"
#include "log.hpp"
#include "server.hpp"

static void request(std::vector<char> & buf);
static void reply(const json::obj & );

json::obj noop( const json::obj & ) {
        return {};
}

std::unordered_map<std::string, json::obj (*)( const json::obj & )> actions {
        { "initialize", server::init },
        { "initialized", noop }
};

int main(int argc, char * argv[]) {
        g_argc = argc;
        g_argv = argv;

        log() << "Language Server called with args:" << std::endl;
        for(int i = 0; i < argc; i++) {
                log() << "\t- " << argv[i] << std::endl;
        }

        // std::cout.setf(std::ios::unitbuf);

        // char buff[1000];
        // int r = 0;
        // while(0 != (r = read(STDIN_FILENO, buff, 1000))) {
        //      for(int i = 0; i < r; i++) {
        //              log() << buff[i];
        //      }
        // }
        // log() << std::endl;

        // return 0;

        std::vector<char> buffer;
        while(true) {
                request(buffer);
                if(buffer.size() == 0) break;

                auto top = json::parse(buffer);

                auto action = actions.find( top["method"] );
                if(action != actions.end()) {
                        log() << "Executing request '" << action->first << "'" << std::endl;
                        json::obj response = {
                                {"id", top["id"] }
                        };

                        try{
                                response["result"] = action->second( top["params"] );
                        } catch( const json::obj & error ) {
                                response["result"] = "";
                                response["error"] = error;
                        }

                        reply(response);
                }
                else {
                        log() << "WARNING no action for method '" << top["method"].dump(4) << "'" << std::endl;
                }
        }

        log() << "Language Server closing after end of file" << std::endl;

        return 0;
}

static void request(std::vector<char> & buffer) {
        std::string lenstr;
        std::getline( std::cin, lenstr );
        if(std::cin.eof()) { buffer.clear(); return; };

        if (lenstr.rfind("Content-Length: ", 0) != 0) {
                log() << "Expected content length bug got '" << lenstr << "' instead " << std::endl;
                std::exit(EXIT_FAILURE);
        }

        size_t idx = sizeof("Content-Length:");
        size_t end;
        size_t len = std::stoul(lenstr.substr(idx), &end);
        if(lenstr.length() != (idx + end + 1)) {
                log() << "Inconsistent size of integer in content length: " << lenstr.length() << " vs " << (idx + end) << std::endl;
        }

        log() << "New request of " << len << " bytes" << std::endl;
        buffer.resize( len + 2 );
        std::cin.read(buffer.data(), buffer.size());

        for(char c : buffer) {
                log() << c;
        }
        log() << std::endl;
        return;
}

static void reply( const json::obj & response) {
        if(response["result"].is_null()) {
                log() << "No response needed" << std::endl;
                return;
        }

        log() << "Responding with : " << response.dump(4) << std::endl;
        const std::string & r = response.dump();
        std::cout << "Content-Length: " << r.length() << "\r\n\r\n";
        std::cout.flush();
        std::cout  << r << "\r\n";
        std::cout.flush();
}