Crow/include/crow/http_response.h

331 lines
10 KiB
C++

#pragma once
#include <string>
#include <unordered_map>
#include <ios>
#include <fstream>
#include <sstream>
#include <sys/stat.h>
#include "crow/http_request.h"
#include "crow/ci_map.h"
#include "crow/socket_adaptors.h"
#include "crow/logging.h"
#include "crow/mime_types.h"
#include "crow/returnable.h"
namespace crow
{
template<typename Adaptor, typename Handler, typename... Middlewares>
class Connection;
/// HTTP response
struct response
{
template<typename Adaptor, typename Handler, typename... Middlewares>
friend class crow::Connection;
int code{200}; ///< The Status code for the response.
std::string body; ///< The actual payload containing the response data.
ci_map headers; ///< HTTP headers.
#ifdef CROW_ENABLE_COMPRESSION
bool compressed = true; ///< If compression is enabled and this is false, the individual response will not be compressed.
#endif
bool is_head_response = false; ///< Whether this is a response to a HEAD request.
bool manual_length_header = false; ///< Whether Crow should automatically add a "Content-Length" header.
/// Set the value of an existing header in the response.
void set_header(std::string key, std::string value)
{
headers.erase(key);
headers.emplace(std::move(key), std::move(value));
}
/// Add a new header to the response.
void add_header(std::string key, std::string value)
{
headers.emplace(std::move(key), std::move(value));
}
const std::string& get_header_value(const std::string& key)
{
return crow::get_header_value(headers, key);
}
// TODO find a better way to format this so that stuff aren't moved down a line
// clang-format off
response() {}
explicit response(int code) : code(code) {}
response(std::string body) : body(std::move(body)) {}
response(int code, std::string body) : code(code), body(std::move(body)) {}
// clang-format on
response(returnable&& value)
{
body = value.dump();
set_header("Content-Type", value.content_type);
}
response(returnable& value)
{
body = value.dump();
set_header("Content-Type", value.content_type);
}
response(int code, returnable& value):
code(code)
{
body = value.dump();
set_header("Content-Type", value.content_type);
}
response(response&& r)
{
*this = std::move(r);
}
response(std::string contentType, std::string body):
body(std::move(body))
{
set_header("Content-Type", mime_types.at(contentType));
}
response(int code, std::string contentType, std::string body):
code(code), body(std::move(body))
{
set_header("Content-Type", mime_types.at(contentType));
}
response& operator=(const response& r) = delete;
response& operator=(response&& r) noexcept
{
body = std::move(r.body);
code = r.code;
headers = std::move(r.headers);
completed_ = r.completed_;
file_info = std::move(r.file_info);
return *this;
}
/// Check if the response has completed (whether response.end() has been called)
bool is_completed() const noexcept
{
return completed_;
}
void clear()
{
body.clear();
code = 200;
headers.clear();
completed_ = false;
file_info = static_file_info{};
}
/// Return a "Temporary Redirect" response.
///
/// Location can either be a route or a full URL.
void redirect(const std::string& location)
{
code = 307;
set_header("Location", location);
}
/// Return a "Permanent Redirect" response.
///
/// Location can either be a route or a full URL.
void redirect_perm(const std::string& location)
{
code = 308;
set_header("Location", location);
}
/// Return a "Found (Moved Temporarily)" response.
///
/// Location can either be a route or a full URL.
void moved(const std::string& location)
{
code = 302;
set_header("Location", location);
}
/// Return a "Moved Permanently" response.
///
/// Location can either be a route or a full URL.
void moved_perm(const std::string& location)
{
code = 301;
set_header("Location", location);
}
void write(const std::string& body_part)
{
body += body_part;
}
/// Set the response completion flag and call the handler (to send the response).
void end()
{
if (!completed_)
{
completed_ = true;
if (is_head_response)
{
set_header("Content-Length", std::to_string(body.size()));
body = "";
manual_length_header = true;
}
if (complete_request_handler_)
{
complete_request_handler_();
}
}
}
/// Same as end() except it adds a body part right before ending.
void end(const std::string& body_part)
{
body += body_part;
end();
}
/// Check if the connection is still alive (usually by checking the socket status).
bool is_alive()
{
return is_alive_helper_ && is_alive_helper_();
}
/// Check whether the response has a static file defined.
bool is_static_type()
{
return file_info.path.size();
}
/// This constains metadata (coming from the `stat` command) related to any static files associated with this response.
///
/// Either a static file or a string body can be returned as 1 response.
struct static_file_info
{
std::string path = "";
struct stat statbuf;
int statResult;
};
///Return a static file as the response body
void set_static_file_info(std::string path)
{
file_info.path = path;
file_info.statResult = stat(file_info.path.c_str(), &file_info.statbuf);
#ifdef CROW_ENABLE_COMPRESSION
compressed = false;
#endif
if (file_info.statResult == 0)
{
std::size_t last_dot = path.find_last_of(".");
std::string extension = path.substr(last_dot + 1);
std::string mimeType = "";
code = 200;
this->add_header("Content-length", std::to_string(file_info.statbuf.st_size));
if (extension != "")
{
mimeType = mime_types.at(extension);
if (mimeType != "")
this->add_header("Content-Type", mimeType);
else
this->add_header("content-Type", "text/plain");
}
}
else
{
code = 404;
this->end();
}
}
/// Stream a static file.
template<typename Adaptor>
void do_stream_file(Adaptor& adaptor)
{
if (file_info.statResult == 0)
{
std::ifstream is(file_info.path.c_str(), std::ios::in | std::ios::binary);
write_streamed(is, adaptor);
}
}
/// Stream the response body (send the body in chunks).
template<typename Adaptor>
void do_stream_body(Adaptor& adaptor)
{
if (body.length() > 0)
{
write_streamed_string(body, adaptor);
}
}
private:
bool completed_{};
std::function<void()> complete_request_handler_;
std::function<bool()> is_alive_helper_;
static_file_info file_info;
template<typename Stream, typename Adaptor>
void write_streamed(Stream& is, Adaptor& adaptor)
{
char buf[16384];
while (is.read(buf, sizeof(buf)).gcount() > 0)
{
std::vector<asio::const_buffer> buffers;
buffers.push_back(boost::asio::buffer(buf));
write_buffer_list(buffers, adaptor);
}
}
// THIS METHOD DOES MODIFY THE BODY, AS IN IT EMPTIES IT
template<typename Adaptor>
void write_streamed_string(std::string& is, Adaptor& adaptor)
{
std::string buf;
std::vector<asio::const_buffer> buffers;
while (is.length() > 16384)
{
//buf.reserve(16385);
buf = is.substr(0, 16384);
is = is.substr(16384);
push_and_write(buffers, buf, adaptor);
}
// Collect whatever is left (less than 16KB) and send it down the socket
// buf.reserve(is.length());
buf = is;
is.clear();
push_and_write(buffers, buf, adaptor);
}
template<typename Adaptor>
inline void push_and_write(std::vector<asio::const_buffer>& buffers, std::string& buf, Adaptor& adaptor)
{
buffers.clear();
buffers.push_back(boost::asio::buffer(buf));
write_buffer_list(buffers, adaptor);
}
template<typename Adaptor>
inline void write_buffer_list(std::vector<asio::const_buffer>& buffers, Adaptor& adaptor)
{
boost::asio::write(adaptor.socket(), buffers, [this](std::error_code ec, std::size_t)
{
if (!ec)
{
return false;
}
else
{
CROW_LOG_ERROR << ec << " - happened while sending buffers";
this->end();
return true;
} });
}
};
} // namespace crow