lnav/src/readline_curses.hh

/**
 * Copyright (c) 2007-2012, Timothy Stack
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @file readline_curses.hh
 */

#ifndef readline_curses_hh
#define readline_curses_hh

#include <cstdio>
#include <exception>
#include <functional>
#include <map>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>

#include <errno.h>
#include <poll.h>
#include <readline/history.h>
#include <readline/readline.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>

#include "base/auto_fd.hh"
#include "base/func_util.hh"
#include "base/result.h"
#include "help_text_formatter.hh"
#include "log_format.hh"
#include "readline_context.hh"
#include "vt52_curses.hh"

extern exec_context INIT_EXEC_CONTEXT;

/**
 * Adapter between readline and curses.  The curses and readline libraries
 * normally do not get along.  So, we need to put readline in another process
 * and present it with a vt52 interface that we then translate to curses.  The
 * vt52 translation is done by the parent class, vt52_curses, while this class
 * takes care of the communication between the two processes.
 */
class readline_curses : public vt52_curses {
public:
    using action = std::function<void(readline_curses*)>;

    class error : public std::exception {
    public:
        error(int err) : e_err(err){};

        int e_err;
    };

    static const int KEY_TIMEOUT = 750 * 1000;

    static const int VALUE_EXPIRATION = 20;

    readline_curses();
    ~readline_curses() override;

    void add_context(int id, readline_context& rc)
    {
        this->rc_contexts[id] = &rc;
    }

    void set_focus_action(const action& va)
    {
        this->rc_focus = va;
    }

    void set_change_action(const action& va)
    {
        this->rc_change = va;
    }

    void set_perform_action(const action& va)
    {
        this->rc_perform = va;
    }

    void set_alt_perform_action(const action& va)
    {
        this->rc_alt_perform = va;
    }

    void set_timeout_action(const action& va)
    {
        this->rc_timeout = va;
    }

    void set_abort_action(const action& va)
    {
        this->rc_abort = va;
    }

    void set_display_match_action(const action& va)
    {
        this->rc_display_match = va;
    }

    void set_display_next_action(const action& va)
    {
        this->rc_display_next = va;
    }

    void set_blur_action(const action& va)
    {
        this->rc_blur = va;
    }

    void set_completion_request_action(const action& va)
    {
        this->rc_completion_request = va;
    }

    void set_value(const std::string& value)
    {
        this->rc_value = value;
        if (this->rc_value.length() > 1024) {
            this->rc_value = this->rc_value.substr(0, 1024);
        }
        this->rc_value_expiration = time(nullptr) + VALUE_EXPIRATION;
        this->set_needs_update();
    }

    std::string get_value() const
    {
        return this->rc_value;
    }

    std::string get_line_buffer() const
    {
        return this->rc_line_buffer;
    }

    void set_alt_value(const std::string& value)
    {
        this->rc_alt_value = value;
    }

    std::string get_alt_value() const
    {
        return this->rc_alt_value;
    }

    void update_poll_set(std::vector<struct pollfd>& pollfds)
    {
        pollfds.push_back((struct pollfd){this->rc_pty[RCF_MASTER], POLLIN, 0});
        pollfds.push_back(
            (struct pollfd){this->rc_command_pipe[RCF_MASTER], POLLIN, 0});
    }

    void handle_key(int ch);

    void check_poll_set(const std::vector<struct pollfd>& pollfds);

    void focus(int context,
               const std::string& prompt,
               const std::string& initial = "");

    void set_alt_focus(bool alt_focus)
    {
        this->rc_is_alt_focus = alt_focus;
    }

    void rewrite_line(int pos, const std::string& value);

    readline_context* get_active_context() const
    {
        require(this->rc_active_context != -1);

        std::map<int, readline_context*>::const_iterator iter;
        iter = this->rc_contexts.find(this->rc_active_context);
        return iter->second;
    }

    void abort();

    void start();

    void do_update() override;

    void window_change()
    {
        struct winsize ws;

        if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1) {
            throw error(errno);
        }
        if (ioctl(this->rc_pty[RCF_MASTER], TIOCSWINSZ, &ws) == -1) {
            throw error(errno);
        }
    }

    void line_ready(const char* line);

    void add_prefix(int context,
                    const std::vector<std::string>& prefix,
                    const std::string& value);

    void clear_prefixes(int context);

    void add_possibility(int context,
                         const std::string& type,
                         const std::string& value);

    void add_possibility(int context,
                         const std::string& type,
                         const char* values[])
    {
        for (int lpc = 0; values[lpc]; lpc++) {
            this->add_possibility(context, type, values[lpc]);
        }
    }

    void add_possibility(int context,
                         const std::string& type,
                         const char** first,
                         const char** last)
    {
        for (; first < last; first++) {
            this->add_possibility(context, type, *first);
        }
    }

    template<template<typename...> class Container>
    void add_possibility(int context,
                         const std::string& type,
                         const Container<std::string>& values)
    {
        for (const auto& str : values) {
            this->add_possibility(context, type, str);
        }
    }

    void rem_possibility(int context,
                         const std::string& type,
                         const std::string& value);
    void clear_possibilities(int context, std::string type);

    const std::vector<std::string>& get_matches() const
    {
        return this->rc_matches;
    }

    int get_match_start() const
    {
        return this->rc_match_start;
    }

    std::string get_match_string() const;

    int get_max_match_length() const
    {
        return this->rc_max_match_length;
    }

    bool consume_ready_for_input()
    {
        auto retval = this->rc_ready_for_input;

        this->rc_ready_for_input = false;
        return retval;
    }

    std::string get_remote_complete_path() const
    {
        return this->rc_remote_complete_path;
    }

private:
    enum {
        RCF_MASTER,
        RCF_SLAVE,

        RCF_MAX_VALUE,
    };

    static void store_matches(char** matches, int num_matches, int max_len);

    friend class readline_context;

    int rc_active_context{-1};
    pid_t rc_child{-1};
    auto_fd rc_pty[2];
    auto_fd rc_command_pipe[2];
    std::map<int, readline_context*> rc_contexts;
    std::string rc_value;
    std::string rc_line_buffer;
    time_t rc_value_expiration{0};
    std::string rc_alt_value;
    int rc_match_start{0};
    int rc_matches_remaining{0};
    int rc_max_match_length{0};
    int rc_match_index{0};
    std::vector<std::string> rc_matches;
    bool rc_is_alt_focus{false};
    bool rc_ready_for_input{false};
    std::string rc_remote_complete_path;

    action rc_focus;
    action rc_change;
    action rc_perform;
    action rc_alt_perform;
    action rc_timeout;
    action rc_abort;
    action rc_display_match;
    action rc_display_next;
    action rc_blur;
    action rc_completion_request;
};

#endif