// Copyright (c) 2019-2024, The Monero Project
//
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//
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// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
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#pragma once
#include <memory>
#include <string>
#include <system_error>
#include <zmq.h>
#include "common/expect.h"
#include "span.h"
//! If the expression is less than 0, return the current ZMQ error code.
#define MONERO_ZMQ_CHECK(...) \
do \
{ \
if (( __VA_ARGS__ ) < 0) \
return {::net::zmq::get_error_code()}; \
} while (0)
//! Print a message followed by the current ZMQ error message.
#define MONERO_LOG_ZMQ_ERROR(...) \
do \
{ \
MERROR( __VA_ARGS__ << ": " << ::net::zmq::get_error_code().message()); \
} while (0)
//! Throw an exception with a custom `msg`, current ZMQ error code, filename, and line number.
#define MONERO_ZMQ_THROW(msg) \
MONERO_THROW( ::net::zmq::get_error_code(), msg )
namespace epee
{
class byte_slice;
}
namespace net
{
namespace zmq
{
//! \return Category for ZMQ errors.
const std::error_category& error_category() noexcept;
//! \return `code` (usally from zmq_errno()`) using `net::zmq::error_category()`.
inline std::error_code make_error_code(int code) noexcept
{
return std::error_code{code, error_category()};
}
//! \return Error from `zmq_errno()` using `net::zmq::error_category()`.
inline std::error_code get_error_code() noexcept
{
return make_error_code(zmq_errno());
}
//! Calls `zmq_term`
class terminate
{
static void call(void* ptr) noexcept;
public:
void operator()(void* ptr) const noexcept
{
if (ptr)
call(ptr);
}
};
//! Calls `zmq_close`
struct close
{
void operator()(void* ptr) const noexcept
{
if (ptr)
zmq_close(ptr);
}
};
//! Unique ZMQ context handle, calls `zmq_term` on destruction.
using context = std::unique_ptr<void, terminate>;
//! Unique ZMQ socket handle, calls `zmq_close` on destruction.
using socket = std::unique_ptr<void, close>;
/*! Retry a ZMQ function on `EINTR` errors. `F` must return an int with
values less than 0 on error.
\param op The ZMQ function to execute + retry
\param args Forwarded to `op`. Must be resuable in case of retry.
\return All errors except for `EINTR`. */
template<typename F, typename... T>
expect<void> retry_op(F op, T&&... args) noexcept(noexcept(op(args...)))
{
for (;;)
{
if (0 <= op(args...))
return success();
const int error = zmq_errno();
if (error != EINTR)
return make_error_code(error);
}
}
/*! Read all parts of the next message on `socket`. Blocks until the entire
next message (all parts) are read, or until `zmq_term` is called on the
`zmq_context` associated with `socket`. If the context is terminated,
`make_error_code(ETERM)` is returned.
\note This will automatically retry on `EINTR`, so exiting on
interrupts requires context termination.
\note If non-blocking behavior is requested on `socket` or by `flags`,
then `net::zmq::make_error_code(EAGAIN)` will be returned if this
would block.
\param socket Handle created with `zmq_socket`.
\param flags See `zmq_msg_read` for possible flags.
\return Message payload read from `socket` or ZMQ error. */
expect<std::string> receive(void* socket, int flags = 0);
/*! Sends `payload` on `socket`. Blocks until the entire message is queued
for sending, or until `zmq_term` is called on the `zmq_context`
associated with `socket`. If the context is terminated,
`make_error_code(ETERM)` is returned.
\note This will automatically retry on `EINTR`, so exiting on
interrupts requires context termination.
\note If non-blocking behavior is requested on `socket` or by `flags`,
then `net::zmq::make_error_code(EAGAIN)` will be returned if this
would block.
\param payload sent as one message on `socket`.
\param socket Handle created with `zmq_socket`.
\param flags See `zmq_send` for possible flags.
\return `success()` if sent, otherwise ZMQ error. */
expect<void> send(epee::span<const std::uint8_t> payload, void* socket, int flags = 0) noexcept;
/*! Sends `payload` on `socket`. Blocks until the entire message is queued
for sending, or until `zmq_term` is called on the `zmq_context`
associated with `socket`. If the context is terminated,
`make_error_code(ETERM)` is returned.
\note This will automatically retry on `EINTR`, so exiting on
interrupts requires context termination.
\note If non-blocking behavior is requested on `socket` or by `flags`,
then `net::zmq::make_error_code(EAGAIN)` will be returned if this
would block.
\param payload sent as one message on `socket`.
\param socket Handle created with `zmq_socket`.
\param flags See `zmq_msg_send` for possible flags.
\post `payload.emtpy()` - ownership is transferred to zmq.
\return `success()` if sent, otherwise ZMQ error. */
expect<void> send(epee::byte_slice&& payload, void* socket, int flags = 0) noexcept;
} // zmq
} // net
