Simple-Web-Server/client_http.hpp

587 lines
23 KiB
C++

#ifndef CLIENT_HTTP_HPP
#define CLIENT_HTTP_HPP
#include "utility.hpp"
#include <mutex>
#include <random>
#include <vector>
#ifdef USE_STANDALONE_ASIO
#include <asio.hpp>
namespace SimpleWeb {
namespace asio = asio;
using error_code = std::error_code;
using errc = std::errc;
using system_error = std::system_error;
namespace make_error_code = std;
using string_view = const std::string &; // TODO c++17: use std::string_view
} // namespace SimpleWeb
#else
#include <boost/asio.hpp>
#include <boost/utility/string_ref.hpp>
namespace SimpleWeb {
namespace asio = boost::asio;
using error_code = boost::system::error_code;
namespace errc = boost::system::errc;
using system_error = boost::system::system_error;
namespace make_error_code = boost::system::errc;
using string_view = boost::string_ref;
} // namespace SimpleWeb
#endif
namespace SimpleWeb {
template <class socket_type>
class Client;
template <class socket_type>
class ClientBase {
public:
class Content : public std::istream {
friend class ClientBase<socket_type>;
public:
size_t size() {
return streambuf.size();
}
/// Convenience function to return std::string. Note that the stream buffer is emptied when this functions is used.
std::string string() {
std::stringstream ss;
ss << rdbuf();
return ss.str();
}
private:
asio::streambuf &streambuf;
Content(asio::streambuf &streambuf) : std::istream(&streambuf), streambuf(streambuf) {}
};
class Response {
friend class ClientBase<socket_type>;
friend class Client<socket_type>;
public:
std::string http_version, status_code;
Content content;
CaseInsensitiveMultimap header;
private:
asio::streambuf content_buffer;
Response() : content(content_buffer) {}
};
class Config {
friend class ClientBase<socket_type>;
private:
Config() {}
public:
/// Set timeout on requests in seconds. Default value: 0 (no timeout).
size_t timeout = 0;
/// Set connect timeout in seconds. Default value: 0 (Config::timeout is then used instead).
size_t timeout_connect = 0;
/// Set proxy server (server:port)
std::string proxy_server;
};
protected:
class Connection {
public:
Connection(const std::string &host, unsigned short port, const Config &config, std::unique_ptr<socket_type> &&socket)
: host(host), port(port), config(config), socket(std::move(socket)) {
if(config.proxy_server.empty())
query = std::unique_ptr<asio::ip::tcp::resolver::query>(new asio::ip::tcp::resolver::query(host, std::to_string(port)));
else {
auto proxy_host_port = parse_host_port(config.proxy_server, 8080);
query = std::unique_ptr<asio::ip::tcp::resolver::query>(new asio::ip::tcp::resolver::query(proxy_host_port.first, std::to_string(proxy_host_port.second)));
}
}
std::string host;
unsigned short port;
Config config;
std::unique_ptr<socket_type> socket;
bool in_use = false;
bool reconnecting = false;
std::unique_ptr<asio::ip::tcp::resolver::query> query;
};
class Session {
public:
Session(const std::shared_ptr<asio::io_service> &io_service, const std::shared_ptr<Connection> &connection, std::unique_ptr<asio::streambuf> &&request_buffer)
: io_service(io_service), connection(connection), request_buffer(std::move(request_buffer)), response(new Response()) {}
std::shared_ptr<asio::io_service> io_service;
std::shared_ptr<Connection> connection;
std::unique_ptr<asio::streambuf> request_buffer;
std::shared_ptr<Response> response;
std::function<void(const error_code &)> callback;
};
public:
/// Set before calling request
Config config;
/// If you have your own asio::io_service, store its pointer here before calling request().
/// When using asynchronous requests, running the io_service is up to the programmer.
std::shared_ptr<asio::io_service> io_service;
virtual ~ClientBase() {}
/// Convenience function to perform synchronous request. The io_service is run within this function.
/// If reusing the io_service for other tasks, please use the asynchronous request functions instead.
std::shared_ptr<Response> request(const std::string &method, const std::string &path = std::string("/"),
string_view content = "", const CaseInsensitiveMultimap &header = CaseInsensitiveMultimap()) {
std::shared_ptr<Response> response;
request(method, path, content, header, [&response](std::shared_ptr<Response> response_, const error_code &ec) {
response = response_;
if(ec)
throw system_error(ec);
});
io_service->reset();
io_service->run();
return response;
}
/// Convenience function to perform synchronous request. The io_service is run within this function.
/// If reusing the io_service for other tasks, please use the asynchronous request functions instead.
std::shared_ptr<Response> request(const std::string &method, const std::string &path, std::istream &content,
const CaseInsensitiveMultimap &header = CaseInsensitiveMultimap()) {
std::shared_ptr<Response> response;
request(method, path, content, header, [&response](std::shared_ptr<Response> response_, const error_code &ec) {
response = response_;
if(ec)
throw system_error(ec);
});
io_service->reset();
io_service->run();
return response;
}
/// Asynchronous request where setting and/or running Client's io_service is required.
void request(const std::string &method, const std::string &path, string_view content, const CaseInsensitiveMultimap &header,
std::function<void(std::shared_ptr<Response>, const error_code &)> &&request_callback_) {
auto session = std::make_shared<Session>(io_service, get_connection(), create_request_header(method, path, header));
auto connection = session->connection;
auto response = session->response;
auto request_callback = std::make_shared<std::function<void(std::shared_ptr<Response>, const error_code &)>>(std::move(request_callback_));
auto connections = this->connections;
auto connections_mutex = this->connections_mutex;
session->callback = [connection, response, request_callback, connections, connections_mutex](const error_code &ec) {
{
std::lock_guard<std::mutex> lock(*connections_mutex);
connection->in_use = false;
// Remove unused connections, but keep one open for HTTP persistent connection:
size_t unused_connections = 0;
for(auto it = connections->begin(); it != connections->end();) {
if((*it)->in_use)
++it;
else {
++unused_connections;
if(unused_connections > 1)
it = connections->erase(it);
else
++it;
}
}
}
if(*request_callback)
(*request_callback)(response, ec);
};
std::ostream write_stream(session->request_buffer.get());
if(content.size() > 0)
write_stream << "Content-Length: " << content.size() << "\r\n";
write_stream << "\r\n"
<< content;
Client<socket_type>::connect(session);
}
/// Asynchronous request where setting and/or running Client's io_service is required.
void request(const std::string &method, const std::string &path, string_view content,
std::function<void(std::shared_ptr<Response>, const error_code &)> &&request_callback) {
request(method, path, content, CaseInsensitiveMultimap(), std::move(request_callback));
}
/// Asynchronous request where setting and/or running Client's io_service is required.
void request(const std::string &method, const std::string &path,
std::function<void(std::shared_ptr<Response>, const error_code &)> &&request_callback) {
request(method, path, std::string(), CaseInsensitiveMultimap(), std::move(request_callback));
}
/// Asynchronous request where setting and/or running Client's io_service is required.
void request(const std::string &method, std::function<void(std::shared_ptr<Response>, const error_code &)> &&request_callback) {
request(method, std::string("/"), std::string(), CaseInsensitiveMultimap(), std::move(request_callback));
}
/// Asynchronous request where setting and/or running Client's io_service is required.
void request(const std::string &method, const std::string &path, std::istream &content, const CaseInsensitiveMultimap &header,
std::function<void(std::shared_ptr<Response>, const error_code &)> &&request_callback_) {
auto session = std::make_shared<Session>(io_service, get_connection(), create_request_header(method, path, header));
auto connection = session->connection;
auto response = session->response;
auto request_callback = std::make_shared<std::function<void(std::shared_ptr<Response>, const error_code &)>>(std::move(request_callback_));
auto connections = this->connections;
auto connections_mutex = this->connections_mutex;
session->callback = [connection, response, request_callback, connections, connections_mutex](const error_code &ec) {
{
std::lock_guard<std::mutex> lock(*connections_mutex);
connection->in_use = false;
// Remove unused connections, but keep one open for HTTP persistent connection:
size_t unused_connections = 0;
for(auto it = connections->begin(); it != connections->end();) {
if((*it)->in_use)
++it;
else {
++unused_connections;
if(unused_connections > 1)
it = connections->erase(it);
else
++it;
}
}
}
if(*request_callback)
(*request_callback)(response, ec);
};
content.seekg(0, std::ios::end);
auto content_length = content.tellg();
content.seekg(0, std::ios::beg);
std::ostream write_stream(session->request_buffer.get());
if(content_length > 0)
write_stream << "Content-Length: " << content_length << "\r\n";
write_stream << "\r\n";
if(content_length > 0)
write_stream << content.rdbuf();
Client<socket_type>::connect(session);
}
/// Asynchronous request where setting and/or running Client's io_service is required.
void request(const std::string &method, const std::string &path, std::istream &content,
std::function<void(std::shared_ptr<Response>, const error_code &)> &&request_callback) {
request(method, path, content, CaseInsensitiveMultimap(), std::move(request_callback));
}
protected:
std::string host;
unsigned short port;
std::shared_ptr<std::vector<std::shared_ptr<Connection>>> connections;
std::shared_ptr<std::mutex> connections_mutex;
ClientBase(const std::string &host_port, unsigned short default_port)
: io_service(new asio::io_service()), connections(new std::vector<std::shared_ptr<Connection>>()), connections_mutex(new std::mutex()) {
auto parsed_host_port = parse_host_port(host_port, default_port);
host = parsed_host_port.first;
port = parsed_host_port.second;
}
std::shared_ptr<Connection> get_connection() {
std::shared_ptr<Connection> connection;
std::lock_guard<std::mutex> lock(*connections_mutex);
for(auto it = connections->begin(); it != connections->end(); ++it) {
if(!(*it)->in_use && !connection) {
connection = *it;
break;
}
}
if(!connection) {
connection = create_connection();
connections->emplace_back(connection);
}
connection->reconnecting = false;
connection->in_use = true;
return connection;
}
virtual std::shared_ptr<Connection> create_connection() = 0;
std::unique_ptr<asio::streambuf> create_request_header(const std::string &method, const std::string &path, const CaseInsensitiveMultimap &header) const {
auto corrected_path = path;
if(corrected_path == "")
corrected_path = "/";
if(!config.proxy_server.empty() && std::is_same<socket_type, asio::ip::tcp::socket>::value)
corrected_path = "http://" + host + ':' + std::to_string(port) + corrected_path;
std::unique_ptr<asio::streambuf> request_buffer(new asio::streambuf());
std::ostream write_stream(request_buffer.get());
write_stream << method << " " << corrected_path << " HTTP/1.1\r\n";
write_stream << "Host: " << host << "\r\n";
for(auto &h : header)
write_stream << h.first << ": " << h.second << "\r\n";
return request_buffer;
}
static std::pair<std::string, unsigned short> parse_host_port(const std::string &host_port, unsigned short default_port) {
std::pair<std::string, unsigned short> parsed_host_port;
size_t host_end = host_port.find(':');
if(host_end == std::string::npos) {
parsed_host_port.first = host_port;
parsed_host_port.second = default_port;
}
else {
parsed_host_port.first = host_port.substr(0, host_end);
parsed_host_port.second = static_cast<unsigned short>(stoul(host_port.substr(host_end + 1)));
}
return parsed_host_port;
}
static std::shared_ptr<asio::deadline_timer> get_timeout_timer(const std::shared_ptr<Session> &session, size_t timeout = 0) {
if(timeout == 0)
timeout = session->connection->config.timeout;
if(timeout == 0)
return nullptr;
auto timer = std::make_shared<asio::deadline_timer>(*session->io_service);
timer->expires_from_now(boost::posix_time::seconds(timeout));
timer->async_wait([session](const error_code &ec) {
if(!ec)
close(session);
});
return timer;
}
static void parse_response_header(const std::shared_ptr<Response> &response) {
std::string line;
getline(response->content, line);
size_t version_end = line.find(' ');
if(version_end != std::string::npos) {
if(5 < line.size())
response->http_version = line.substr(5, version_end - 5);
if((version_end + 1) < line.size())
response->status_code = line.substr(version_end + 1, line.size() - (version_end + 1) - 1);
getline(response->content, line);
size_t param_end;
while((param_end = line.find(':')) != std::string::npos) {
size_t value_start = param_end + 1;
if((value_start) < line.size()) {
if(line[value_start] == ' ')
value_start++;
if(value_start < line.size())
response->header.insert(std::make_pair(line.substr(0, param_end), line.substr(value_start, line.size() - value_start - 1)));
}
getline(response->content, line);
}
}
}
static void write(const std::shared_ptr<Session> &session) {
auto timer = get_timeout_timer(session);
asio::async_write(*session->connection->socket, session->request_buffer->data(), [session, timer](const error_code &ec, size_t /*bytes_transferred*/) {
if(timer)
timer->cancel();
if(!ec)
read(session);
else {
close(session);
session->callback(ec);
}
});
}
static void read(const std::shared_ptr<Session> &session) {
auto timer = get_timeout_timer(session);
asio::async_read_until(*session->connection->socket, session->response->content_buffer, "\r\n\r\n", [session, timer](const error_code &ec, size_t bytes_transferred) {
if(timer)
timer->cancel();
if(!ec) {
session->connection->reconnecting = false;
size_t num_additional_bytes = session->response->content_buffer.size() - bytes_transferred;
parse_response_header(session->response);
auto header_it = session->response->header.find("Content-Length");
if(header_it != session->response->header.end()) {
auto content_length = stoull(header_it->second);
if(content_length > num_additional_bytes) {
auto timer = get_timeout_timer(session);
asio::async_read(*session->connection->socket, session->response->content_buffer, asio::transfer_exactly(content_length - num_additional_bytes), [session, timer](const error_code &ec, size_t /*bytes_transferred*/) {
if(timer)
timer->cancel();
if(!ec)
session->callback(ec);
else {
close(session);
session->callback(ec);
}
});
}
else
session->callback(ec);
}
else if((header_it = session->response->header.find("Transfer-Encoding")) != session->response->header.end() && header_it->second == "chunked") {
auto tmp_streambuf = std::make_shared<asio::streambuf>();
read_chunked(session, tmp_streambuf);
}
else if(session->response->http_version < "1.1" || ((header_it = session->response->header.find("Session")) != session->response->header.end() && header_it->second == "close")) {
auto timer = get_timeout_timer(session);
asio::async_read(*session->connection->socket, session->response->content_buffer, [session, timer](const error_code &ec, size_t /*bytes_transferred*/) {
if(timer)
timer->cancel();
if(!ec)
session->callback(ec);
else {
close(session);
if(ec == asio::error::eof) {
error_code ec;
session->callback(ec);
}
else
session->callback(ec);
}
});
}
else
session->callback(ec);
}
else {
if(!session->connection->reconnecting) {
session->connection->reconnecting = true;
close(session);
Client<socket_type>::connect(session);
}
else {
close(session);
session->callback(ec);
}
}
});
}
static void read_chunked(const std::shared_ptr<Session> &session, const std::shared_ptr<asio::streambuf> &tmp_streambuf) {
auto timer = get_timeout_timer(session);
asio::async_read_until(*session->connection->socket, session->response->content_buffer, "\r\n", [session, tmp_streambuf, timer](const error_code &ec, size_t bytes_transferred) {
if(timer)
timer->cancel();
if(!ec) {
std::string line;
getline(session->response->content, line);
bytes_transferred -= line.size() + 1;
line.pop_back();
std::streamsize length = stol(line, 0, 16);
auto num_additional_bytes = static_cast<std::streamsize>(session->response->content_buffer.size() - bytes_transferred);
auto post_process = [session, tmp_streambuf, length] {
std::ostream tmp_stream(tmp_streambuf.get());
if(length > 0) {
std::vector<char> buffer(static_cast<size_t>(length));
session->response->content.read(&buffer[0], length);
tmp_stream.write(&buffer[0], length);
}
//Remove "\r\n"
session->response->content.get();
session->response->content.get();
if(length > 0)
read_chunked(session, tmp_streambuf);
else {
std::ostream response_stream(&session->response->content_buffer);
response_stream << tmp_stream.rdbuf();
error_code ec;
session->callback(ec);
}
};
if((2 + length) > num_additional_bytes) {
auto timer = get_timeout_timer(session);
asio::async_read(*session->connection->socket, session->response->content_buffer, asio::transfer_exactly(2 + length - num_additional_bytes), [session, post_process, timer](const error_code &ec, size_t /*bytes_transferred*/) {
if(timer)
timer->cancel();
if(!ec)
post_process();
else {
close(session);
session->callback(ec);
}
});
}
else
post_process();
}
else {
close(session);
session->callback(ec);
}
});
}
static void close(const std::shared_ptr<Session> &session) {
error_code ec;
session->connection->socket->lowest_layer().shutdown(asio::ip::tcp::socket::shutdown_both, ec);
session->connection->socket->lowest_layer().close(ec);
}
};
template <class socket_type>
class Client : public ClientBase<socket_type> {};
typedef asio::ip::tcp::socket HTTP;
template <>
class Client<HTTP> : public ClientBase<HTTP> {
public:
friend ClientBase<HTTP>;
Client(const std::string &server_port_path) : ClientBase<HTTP>::ClientBase(server_port_path, 80) {}
protected:
std::shared_ptr<Connection> create_connection() override {
return std::make_shared<Connection>(host, port, config, std::unique_ptr<HTTP>(new HTTP(*io_service)));
}
static void connect(const std::shared_ptr<Session> &session) {
if(!session->connection->socket->lowest_layer().is_open()) {
auto resolver = std::make_shared<asio::ip::tcp::resolver>(*session->io_service);
auto timer = get_timeout_timer(session, session->connection->config.timeout_connect);
resolver->async_resolve(*session->connection->query, [session, timer, resolver](const error_code &ec, asio::ip::tcp::resolver::iterator it) {
if(timer)
timer->cancel();
if(!ec) {
auto timer = get_timeout_timer(session, session->connection->config.timeout_connect);
asio::async_connect(*session->connection->socket, it, [session, timer, resolver](const error_code &ec, asio::ip::tcp::resolver::iterator /*it*/) {
if(timer)
timer->cancel();
if(!ec) {
asio::ip::tcp::no_delay option(true);
session->connection->socket->set_option(option);
write(session);
}
else {
close(session);
session->callback(ec);
}
});
}
else {
close(session);
session->callback(ec);
}
});
}
else
write(session);
}
};
} // namespace SimpleWeb
#endif /* CLIENT_HTTP_HPP */