mastodonpp/include/curl_wrapper.hpp

269 lines
6.8 KiB
C++

/* 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 <variant>
#include <vector>
namespace mastodonpp
{
using std::map;
using std::mutex;
using std::string;
using std::string_view;
using std::variant;
using std::vector;
/*!
* @brief The HTTP method.
*
* @since 0.1.0
*/
enum class http_method
{
GET,
POST,
PATCH,
PUT,
DELETE
};
/*!
* @brief std::map of parameters for %API calls.
*
* Example:
* @code
* parametermap parameters
* {
* {"id", "12"},
* {"poll[options]", vector<string_view>{"Yes", "No", "Maybe"}}
* };
* @endcode
*
* @since 0.1.0
*/
using parametermap = map<string_view, variant<string_view, vector<string_view>>>;
/*!
* @brief Handles the details of network connections.
*
* You don't need to use this.
*
* @since 0.1.0
*
* @headerfile curl_wrapper.hpp mastodonpp/curl_wrapper.hpp
*/
class CURLWrapper
{
public:
/*!
* @brief Initializes curl and sets up connection.
*
* The first time an instance of CURLWrapper is created, it calls
* `curl_global_init`, which is not thread-safe. For more information
* consult [curl_global_init(3)]
* (https://curl.haxx.se/libcurl/c/curl_global_init.html).
*
* @since 0.1.0
*/
CURLWrapper();
//! Copy constructor
CURLWrapper(const CURLWrapper &other) = delete;
//! Move constructor
CURLWrapper(CURLWrapper &&other) noexcept = delete;
/*!
* @brief Cleans up curl and connection.
*
* Calls `curl_global_cleanup`, which is not thread-safe. For more
* information consult [curl_global_cleanup(3)]
* (https://curl.haxx.se/libcurl/c/curl_global_cleanup.html).
*
* @since 0.1.0
*/
virtual ~CURLWrapper() noexcept;
//! Copy assignment operator
CURLWrapper& operator=(const CURLWrapper &other) = delete;
//! Move assignment operator
CURLWrapper& operator=(CURLWrapper &&other) noexcept = delete;
/*!
* @brief Returns pointer to the CURL easy handle.
*
* You can use this handle to set or modify curl options. For more
* information consult [curl_easy_setopt(3)]
* (https://curl.haxx.se/libcurl/c/curl_easy_setopt.html).
*
* @since 0.1.0
*/
inline CURL *get_curl_easy_handle()
{
return _connection;
}
/*!
* @brief Set the proxy to use.
*
* See [CURLOPT_PROXY(3)]
* (https://curl.haxx.se/libcurl/c/CURLOPT_PROXY.html).
*
* @param proxy Examples: "socks4a://127.0.0.1:9050", "http://[::1]:3128".
*
* @since 0.1.0
*/
void set_proxy(string_view proxy);
/*!
* @brief Cancel the stream.
*
* The stream will be cancelled, usually whithin a second. The @link
* answer_type::curl_error_code curl_error_code @endlink of the answer will
* be set to 42 (`CURLE_ABORTED_BY_CALLBACK`).
*
* @since 0.1.0
*/
void cancel_stream();
protected:
/*!
* @brief Mutex for #get_buffer a.k.a. _curl_buffer_body.
*
* This mutex is locked in `writer_body()` and
* Connection::get_new_stream_contents before anything is read or written
* from/to _curl_buffer_body.
*
* @since 0.1.0
*/
mutex buffer_mutex;
/*!
* @brief Make a HTTP request.
*
* @param method The HTTP method.
* @param uri The full URI.
* @param parameters A map of parameters.
*
* @since 0.1.0
*/
[[nodiscard]]
answer_type make_request(const http_method &method, string uri,
const parametermap &parameters);
/*!
* @brief Returns a reference to the buffer libcurl writes into.
*
* @since 0.1.0
*/
[[nodiscard]]
string &get_buffer()
{
return _curl_buffer_body;
}
private:
CURL *_connection;
char _curl_buffer_error[CURL_ERROR_SIZE];
string _curl_buffer_headers;
string _curl_buffer_body;
bool _stream_cancelled;
/*!
* @brief libcurl write callback function.
*
* @since 0.1.0
*/
size_t writer_body(char *data, size_t size, size_t nmemb);
/*!
* @brief Wrapper for curl, because it can only call static member
* functions.
*
* <https://curl.haxx.se/docs/faq.html#Using_C_non_static_functions_f>
*
* @since 0.1.0
*/
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);
}
//! @copydoc writer_body
size_t writer_header(char *data, size_t size, size_t nmemb);
//! @copydoc writer_body_wrapper
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);
}
/*!
* @brief libcurl transfer info function.
*
* Used to cancel streams.
*
* @since 0.1.0
*/
int progress(void *clientp, curl_off_t dltotal, curl_off_t dlnow,
curl_off_t ultotal, curl_off_t ulnow);
//! @copydoc writer_body_wrapper
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);
}
/*!
* @brief Setup libcurl connection.
*
* @since 0.1.0
*/
void setup_curl();
/*!
* @brief Add parameters to URI.
*
* @param uri Reference to the URI.
* @param parameters The parametermap.
*
* @since 0.1.0
*/
void add_parameters_to_uri(string &uri, const parametermap &parameters);
};
} // namespace mastodonpp
#endif // MASTODONPP_CURL_WRAPPER_HPP