// Copyright Pan Yue 2021.

// Distributed under the Boost Software License, Version 1.0. (See

// accompanying file LICENSE_1_0.txt or copy at

// http://www.boost.org/LICENSE_1_0.txt)

// TODO:

// 1. posix::stream_descriptor need windows version

// 2. call_* need return async.Handle

# ifndef EVENT_LOOP_PY2021_HPP

# define EVENT_LOOP_PY2021_HPP

#include <unordered_map>

#include <boost/asio.hpp>

#include <boost/python.hpp>

#include <boost/mpl/vector.hpp>

namespace boost { namespace python { namespace asio {

class event_loop

{

public:

event_loop(const boost::asio::io_context::strand& strand): _strand{strand}

{

try

{

_pymod_ssl = import("ssl");

}

catch (const error_already_set& e)

{

if (PyErr_ExceptionMatches(PyExc_ImportError))

{

PyErr_Clear();

}

}

}

// TODO: An instance of asyncio.Handle is returned, which can be used later to cancel the callback.

inline void call_soon(object f)

{

_strand.post([f]{

PyEval_AcquireLock();

f();

PyEval_ReleaseLock();

});

}

// TODO: implement this

inline void call_soon_thread_safe(object f) {};

// Schedule callback to be called after the given delay number of seconds

// TODO: An instance of asyncio.Handle is returned, which can be used later to cancel the callback.

void call_later(double delay, object f);

void call_at(double when, object f);

inline double time()

{

return std::chrono::steady_clock::now().time_since_epoch().count();

}

inline void add_reader(int fd, object f)

{

_async_wait_fd(fd, f, _read_key(fd));

}

inline void remove_reader(int fd)

{

_descriptor_map.erase(_read_key(fd));

}

inline void add_writer(int fd, object f)

{

_async_wait_fd(fd, f, _write_key(fd));

}

inline void remove_writer(int fd)

{

_descriptor_map.erase(_write_key(fd));

}

object sock_recv(object sock, size_t nbytes);

object sock_recv_into(object sock, object buffer);

object sock_sendall(object sock, object data);

object sock_connect(object sock, object address);

object sock_accept(object sock);

object sock_sendfile(object sock, object file, int offset = 0, int count = 0, bool fallback = true);

object start_tls(object transport, object protocol, object sslcontext,

bool server_side = false,

object server_hostname = object(),

object ssl_handshake_timeout = object());

object getaddrinfo(object host, int port, int family = 0, int type = 0, int proto = 0, int flags = 0);

object getnameinfo(object sockaddr, int flags = 0);

void set_exception_handler(object handler)

{

if (handler != object() && !PyObject_HasAttrString(handler.ptr(), "__call__")) {

PyErr_SetString(PyExc_TypeError, "A callable object or None is expected");

throw_error_already_set();

}

_exception_handler = handler;

}

object get_exception_handler()

{

return _exception_handler;

}

void default_exception_handler(object context);

void call_exception_handler(object context);

object create_future();

// TODO

inline bool get_debug()

{

return false;

}

private:

object _pymod_ssl = object();

object _pymod_socket = import("socket");

object _pymod_traceback = import("traceback");

object _pymod_asyncio_futures = import("asyncio").attr("futures");

object _py_logger = import("asyncio.log").attr("logger");

object _pymod_concurrent_futures = import("concurrent").attr("futures");

object _exception_handler = object();

boost::asio::io_context::strand _strand;

// read: key = fd * 2 + 0, write: key = fd * 2 + 1

std::unordered_map<int, std::unique_ptr<boost::asio::posix::stream_descriptor>> _descriptor_map;

inline int _read_key(int fd)

{

return fd * 2;

}

inline int _write_key(int fd)

{

return fd * 2 + 1;

}

template<typename F>

void _async_wait_fd(int fd, F f, int key)

{

// add descriptor

if (_descriptor_map.find(key) == _descriptor_map.end())

{

_descriptor_map.emplace(key,

std::move(std::make_unique<boost::asio::posix::stream_descriptor>(_strand.context(), fd))

);

}

_descriptor_map.find(key)->second->async_wait(boost::asio::posix::descriptor::wait_type::wait_read,

boost::asio::bind_executor(_strand, [this, key, f] (const boost::system::error_code& ec)

{

_descriptor_map.erase(key);

f();

}));

return;

}

static void _sock_connect_cb(object pymod_socket, object fut, object sock, object addr);

static void _sock_accept(event_loop& loop, object fut, object sock);

};

void set_default_event_loop(const boost::asio::io_context::strand& strand);

}}} // namespace boost::python::asio

# endif