curl_wrapper.hpp

/*  This file is part of mastodonpp.
 *  Copyright © 2020 tastytea <tastytea@tastytea.de>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, version 3.
 *
 *  This program 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef MASTODONPP_CURL_WRAPPER_HPP
#define MASTODONPP_CURL_WRAPPER_HPP
 
#include "answer.hpp"
 
#include "curl/curl.h"
 
#include <map>
#include <mutex>
#include <string>
#include <string_view>
#include <utility>
#include <variant>
#include <vector>
 
namespace mastodonpp
{
 
using std::map;
using std::mutex;
using std::string;
using std::string_view;
using std::pair;
using std::variant;
using std::vector;
 
enum class http_method
{
    GET,
    POST,
    PATCH,
    PUT,
    DELETE
};
 
using parametermap =
    map<string_view, variant<string_view, vector<string_view>>>;
 
using parameterpair =
    pair<string_view, variant<string_view, vector<string_view>>>;
 
class CURLWrapper
{
public:
    CURLWrapper();
 
    CURLWrapper(const CURLWrapper &other) = delete;
 
    CURLWrapper(CURLWrapper &&other) noexcept = delete;
 
    virtual ~CURLWrapper() noexcept;
 
    CURLWrapper& operator=(const CURLWrapper &other) = delete;
 
    CURLWrapper& operator=(CURLWrapper &&other) noexcept = delete;
 
    inline CURL *get_curl_easy_handle()
    {
        return _connection;
    }
 
    void set_proxy(string_view proxy);
 
protected:
    mutex buffer_mutex;
 
    [[nodiscard]]
    answer_type make_request(const http_method &method, string uri,
                             const parametermap &parameters);
 
    [[nodiscard]]
    string &get_buffer()
    {
        return _curl_buffer_body;
    }
 
    inline void cancel_stream()
    {
        _stream_cancelled = true;
    }
 
    void set_access_token(const string_view access_token);
 
private:
    CURL *_connection;
    char _curl_buffer_error[CURL_ERROR_SIZE];
    string _curl_buffer_headers;
    string _curl_buffer_body;
    bool _stream_cancelled;
 
    size_t writer_body(char *data, size_t size, size_t nmemb);
 
    static inline size_t writer_body_wrapper(char *data, size_t sz,
                                             size_t nmemb, void *f)
    {
        return static_cast<CURLWrapper*>(f)->writer_body(data, sz, nmemb);
    }
 
    size_t writer_header(char *data, size_t size, size_t nmemb);
 
    static inline size_t writer_header_wrapper(char *data, size_t sz,
                                               size_t nmemb, void *f)
    {
        return static_cast<CURLWrapper*>(f)->writer_header(data, sz, nmemb);
    }
 
    int progress(void *clientp, curl_off_t dltotal, curl_off_t dlnow,
                 curl_off_t ultotal, curl_off_t ulnow);
 
    static inline int progress_wrapper(void *f, void *clientp,
                                       curl_off_t dltotal, curl_off_t dlnow,
                                       curl_off_t ultotal, curl_off_t ulnow)
    {
        return static_cast<CURLWrapper*>(f)->progress(clientp, dltotal, dlnow,
                                                      ultotal, ulnow);
    }
 
    void setup_curl();
 
    bool replace_parameter_in_uri(string &uri, const parameterpair &parameter);
 
    void add_parameters_to_uri(string &uri, const parametermap &parameters);
 
    void add_mime_part(curl_mime *mime,
                       string_view name, string_view data) const;
 
    curl_mime *parameters_to_curl_mime(string &uri,
                                       const parametermap &parameters);
};
 
} // namespace mastodonpp
 
#endif  // MASTODONPP_CURL_WRAPPER_HPP