FlowLineNoise.actor.cpp

/*
 * FlowLineNoise.actor.cpp
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "flow/actorcompiler.h"
#include "FlowLineNoise.h"
#include "flow/IThreadPool.h"

#define BOOST_SYSTEM_NO_LIB
#define BOOST_DATE_TIME_NO_LIB
#define BOOST_REGEX_NO_LIB
#include "boost/asio.hpp"

#include "flow/ThreadHelper.actor.h"

#if __unixish__
    #define HAVE_LINENOISE 1
    #include "linenoise/linenoise.h"
#else
    #define HAVE_LINENOISE 0
#endif

struct LineNoiseReader : IThreadPoolReceiver {
    virtual void init() {}

    struct Read : TypedAction<LineNoiseReader, Read> {
        std::string prompt;
        ThreadReturnPromise<Optional<std::string>> result;

        virtual double getTimeEstimate() { return 0.0; }
        explicit Read(std::string const& prompt) : prompt(prompt) {}
    };

    void action(Read& r) {
        try {
            r.result.send( read(r.prompt) );
        } catch (Error& e) {
            r.result.sendError(e);
        } catch (...) {
            r.result.sendError(unknown_error());
        }
    }

private:
    Optional<std::string> read(std::string const& prompt) {
        #if HAVE_LINENOISE
            errno = 0;
            char* line = linenoise(prompt.c_str());
            if (line) {
                std::string s(line);
                free(line);
                return s;
            } else {
                if (errno == EAGAIN) // Ctrl-C
                    return std::string();
                return Optional<std::string>();
            }
        #else
            std::string line;
            std::fputs( prompt.c_str(), stdout );
            if (!std::getline( std::cin, line ).eof()) {
                return line;
            } else
                return Optional<std::string>();
        #endif
    }
};

LineNoise::LineNoise(
        std::function< void(std::string const&, std::vector<std::string>&) > _completion_callback,
        std::function< Hint(std::string const&) > _hint_callback,
        int maxHistoryLines,
        bool multiline )
 : threadPool( createGenericThreadPool() )
{
    reader = new LineNoiseReader();

    #if HAVE_LINENOISE
        // It should be OK to call these functions from this thread, since read() can't be called yet
        // The callbacks passed to linenoise*() will be invoked from the thread pool, and use onMainThread() to safely invoke the callbacks we've been given

        // linenoise doesn't provide any form of data parameter to callbacks, so we have to use static variables
        static std::function< void(std::string const&, std::vector<std::string>&) > completion_callback;
        static std::function< Hint(std::string const&) > hint_callback;
        completion_callback = _completion_callback;
        hint_callback = _hint_callback;

        linenoiseHistorySetMaxLen( maxHistoryLines );
        linenoiseSetMultiLine( multiline );
        linenoiseSetCompletionCallback( [](const char* line, linenoiseCompletions* lc) {
            // This code will run in the thread pool
            std::vector<std::string> completions;
            onMainThread( [line, &completions]() -> Future<Void> {
                completion_callback(line, completions);
                return Void();
            }).getBlocking();
            for( auto const& c : completions )
                linenoiseAddCompletion( lc, c.c_str() );
        });
        /*linenoiseSetHintsCallback( [](const char* line, int* color, int*bold) -> const char* {
            Hint h = onMainThread( [line]() -> Future<Hint> {
                return hint_callback(line);
            }).getBlocking();
            if (!h.valid) return NULL;
            *color = h.color;
            *bold = h.bold;
            return strdup( h.text.c_str() );
        });
        linenoiseSetFreeHintsCallback( free );*/
    #endif

    threadPool->addThread(reader);
}

LineNoise::~LineNoise() {
    threadPool.clear();
}

Future<Optional<std::string>> LineNoise::read( std::string const& prompt ) {
    auto r = new LineNoiseReader::Read(prompt);
    auto f = r->result.getFuture();
    threadPool->post(r);
    return f;
}

ACTOR Future<Void> waitKeyboardInterrupt(boost::asio::io_service* ios) {
    state boost::asio::signal_set signals(*ios, SIGINT);
    Promise<Void> result;
    signals.async_wait([result](const boost::system::error_code& error, int signal_number) {
        if (error) {
            result.sendError(io_error());
        } else {
            result.send(Void());
        }
    });

    Void _ = wait(result.getFuture());
    return Void();
}

Future<Void> LineNoise::onKeyboardInterrupt() {
    boost::asio::io_service* ios = (boost::asio::io_service*)g_network->global(INetwork::enASIOService);
    if (!ios) return Never();
    return waitKeyboardInterrupt(ios);
}

void LineNoise::historyAdd( std::string const& line ) {
    #if HAVE_LINENOISE
        linenoiseHistoryAdd( line.c_str() );
    #endif
}
void LineNoise::historyLoad( std::string const& filename ) {
    #if HAVE_LINENOISE
        if(linenoiseHistoryLoad(filename.c_str()) != 0) {
            throw io_error();
        }
    #endif
}
void LineNoise::historySave( std::string const& filename ) {
    #if HAVE_LINENOISE
        if(linenoiseHistorySave(filename.c_str()) != 0) {
            throw io_error();
        }
    #endif
}