ctlseqs/src/ctlseqs.hh

/**
 * ctlseqs.hh - C++ wrapper for the ctlseqs library
 * 
 * Copyright (C) 2020  CismonX <admin@cismon.net>
 * 
 * This file is part of the ctlseqs library.
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this library.  If not, see <https://www.gnu.org/licenses/>.
 */

#ifndef CTLSEQS_HH_
#define CTLSEQS_HH_

#include "ctlseqs.h"

#include <chrono>
#include <new>
#include <stdexcept>
#include <vector>

namespace ctlseqs {

    // Control sequence matcher
    class matcher final {

        ctlseqs_matcher *const matcher_;

        friend class reader;

    public:

        matcher(matcher const &matcher) = delete;

        matcher() : matcher_(ctlseqs_matcher_init()) {
            if (matcher_ == nullptr) {
                throw std::bad_alloc();
            }
        }

        void patterns(std::vector<char const *> const &patterns) {
            ctlseqs_matcher_opts opts { patterns.data(), patterns.size() };
            switch (ctlseqs_matcher_setopt(matcher_, &opts)) {
                case CTLSEQS_NOMEM:
                    throw std::bad_alloc();
            }
        }

        ~matcher() {
            ctlseqs_matcher_free(matcher_);
        }
    };

    // Buffer for parsed sequence
    template <std::size_t N>
    class buffer final {

        ctlseqs_value buffer_[N];

    public:

        // Get string value
        char const *str(std::size_t idx) const {
            return buffer_[idx].str;
        }

        // Get integer value by index
        unsigned long num(std::size_t idx) const {
            return buffer_[idx].num;
        }
    };

    // Control sequence reader
    class reader final {

        ctlseqs_reader *const reader_;

        ctlseqs_value *buffer_;
        size_t         maxlen_;
        int            fd_;
        bool           no_poll_;
        bool           retain_partial_;
        bool           options_modified_;

        ssize_t setopt_and_read(matcher const &matcher, int timeout) {
            if (options_modified_) {
                unsigned flags = retain_partial_ * CTLSEQS_READER_RETAIN_PARTIAL | no_poll_ * CTLSEQS_READER_NO_POLL;
                ctlseqs_reader_opts opts { buffer_, maxlen_, fd_, flags };
                switch (ctlseqs_reader_setopt(reader_, &opts)) {
                    case CTLSEQS_NOMEM:
                        throw std::bad_alloc();
                }
                options_modified_ = false;
            }
            ssize_t retval = ctlseqs_read(reader_, matcher.matcher_, timeout);
            switch (retval) {
                case CTLSEQS_ERROR:
                    throw std::runtime_error("read failed");
            }
            return retval;
        }

    public:

        reader(reader const &reader) = delete;

        reader() : reader_(ctlseqs_reader_init()) {
            if (reader_ == nullptr) {
                throw std::bad_alloc();
            }
        }

        // Set buffer for parsed message
        template <std::size_t N>
        void buffer(buffer<N> const &buffer) {
            buffer_ = reinterpret_cast<ctlseqs_value *>(&buffer);
            options_modified_ = true;
        }

        // Set file descriptor to read from
        void fd(int fd) {
            fd_ = fd;
            options_modified_ = true;
        }

        // Set maximum read size
        void maxlen(std::size_t maxlen) {
            maxlen_ = maxlen;
            options_modified_ = true;
        }

        // Do not poll() before read()
        void no_poll(bool enabled = true) {
            no_poll_ = enabled;
            options_modified_ = true;
        }

        // Retain data after a partial match
        void retain_partial(bool enabled = true) {
            retain_partial_ = enabled;
            options_modified_ = true;
        }

        // Read without timemout
        ssize_t read(matcher const &matcher) {
            return setopt_and_read(matcher, -1);
        }

        // Read with timeout
        template <typename R, typename P>
        ssize_t read(matcher const &matcher, std::chrono::duration<R, P> timeout) {
            int timeout_millis = std::chrono::duration_cast<std::chrono::milliseconds>(timeout).count();
            return setopt_and_read(matcher.matcher_, timeout_millis);
        }

        ~reader() {
            ctlseqs_reader_free(reader_);
        }
    };
}

#endif  // !CTLSEQS_HH_