lnav/src/command_executor.hh

/**
 * Copyright (c) 2015, 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.
 */

#ifndef LNAV_COMMAND_EXECUTOR_H
#define LNAV_COMMAND_EXECUTOR_H

#include <future>
#include <stack>
#include <string>

#include <sqlite3.h>

#include "auto_fd.hh"
#include "bookmarks.hh"
#include "fmt/format.h"
#include "ghc/filesystem.hpp"
#include "optional.hpp"
#include "shlex.resolver.hh"
#include "vis_line.hh"

struct exec_context;
class attr_line_t;
class logline_value;

typedef int (*sql_callback_t)(exec_context& ec, sqlite3_stmt* stmt);
int sql_callback(exec_context& ec, sqlite3_stmt* stmt);

typedef std::future<std::string> (*pipe_callback_t)(exec_context& ec,
                                                    const std::string& cmdline,
                                                    auto_fd& fd);

struct exec_context {
    enum class perm_t {
        READ_WRITE,
        READ_ONLY,
    };

    using output_t = std::pair<FILE*, int (*)(FILE*)>;

    exec_context(std::vector<logline_value>* line_values = nullptr,
                 sql_callback_t sql_callback = ::sql_callback,
                 pipe_callback_t pipe_callback = nullptr);

    bool is_read_write() const
    {
        return this->ec_perms == perm_t::READ_WRITE;
    }

    bool is_read_only() const
    {
        return this->ec_perms == perm_t::READ_ONLY;
    }

    exec_context& with_perms(perm_t perms)
    {
        this->ec_perms = perms;
        return *this;
    }

    std::string get_error_prefix();

    template<typename... Args>
    Result<std::string, std::string> make_error(fmt::string_view format_str,
                                                const Args&... args)
    {
        return Err(this->get_error_prefix()
                   + fmt::vformat(format_str, fmt::make_format_args(args...)));
    }

    nonstd::optional<FILE*> get_output()
    {
        for (auto iter = this->ec_output_stack.rbegin();
             iter != this->ec_output_stack.rend();
             ++iter)
        {
            if (iter->second && (*iter->second).first) {
                return (*iter->second).first;
            }
        }

        return nonstd::nullopt;
    }

    void set_output(const std::string& name, FILE* file, int (*closer)(FILE*));

    void clear_output();

    struct source_guard {
        source_guard(exec_context& context) : sg_context(context) {}

        ~source_guard()
        {
            this->sg_context.ec_source.pop();
        }

        exec_context& sg_context;
    };

    struct output_guard {
        explicit output_guard(exec_context& context,
                              std::string name = "default",
                              const nonstd::optional<output_t>& file
                              = nonstd::nullopt);

        ~output_guard();

        exec_context& sg_context;
    };

    source_guard enter_source(const std::string& path, int line_number)
    {
        this->ec_source.emplace(path, line_number);
        return {*this};
    }

    scoped_resolver create_resolver()
    {
        return {
            &this->ec_local_vars.top(),
            &this->ec_global_vars,
        };
    }

    vis_line_t ec_top_line{0_vl};
    bool ec_dry_run{false};
    perm_t ec_perms{perm_t::READ_WRITE};

    std::map<std::string, std::string> ec_override;
    std::vector<logline_value>* ec_line_values;
    std::stack<std::map<std::string, std::string>> ec_local_vars;
    std::map<std::string, std::string> ec_global_vars;
    std::vector<ghc::filesystem::path> ec_path_stack;
    std::stack<std::pair<std::string, int>> ec_source;

    std::vector<std::pair<std::string, nonstd::optional<output_t>>>
        ec_output_stack;

    std::unique_ptr<attr_line_t> ec_accumulator;

    sql_callback_t ec_sql_callback;
    pipe_callback_t ec_pipe_callback;
};

Result<std::string, std::string> execute_command(exec_context& ec,
                                                 const std::string& cmdline);

Result<std::string, std::string> execute_sql(exec_context& ec,
                                             const std::string& sql,
                                             std::string& alt_msg);
Result<std::string, std::string> execute_file(exec_context& ec,
                                              const std::string& path_and_args,
                                              bool multiline = true);
Result<std::string, std::string> execute_any(exec_context& ec,
                                             const std::string& cmdline);
void execute_init_commands(
    exec_context& ec,
    std::vector<std::pair<Result<std::string, std::string>, std::string>>&
        msgs);

std::future<std::string> pipe_callback(exec_context& ec,
                                       const std::string& cmdline,
                                       auto_fd& fd);

int sql_progress(const struct log_cursor& lc);
void sql_progress_finished();

void add_global_vars(exec_context& ec);

#endif  // LNAV_COMMAND_EXECUTOR_H