Files
scylladb/exceptions/coordinator_result.hh
Piotr Dulikowski efc3953c0a transport: add rate_limit_error
Adds a CQL protocol extension which introduces the rate_limit_error. The
new error code will be used to indicate that the operation failed due to
it exceeding the allowed per-partition rate limit.

The error code is supposed to be returned only if the corresponding CQL
extension is enabled by the client - if it's not enabled, then
Config_error will be returned in its stead.
2022-06-22 20:07:58 +02:00

45 lines
1.3 KiB
C++

/*
* Copyright (C) 2022-present ScyllaDB
*/
/*
* SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0)
*/
#pragma once
#include "exceptions.hh"
#include <boost/outcome/result.hpp>
#include "utils/exception_container.hh"
#include "utils/result.hh"
namespace exceptions {
// Allows to pass a coordinator exception as a value. With coordinator_result,
// it is possible to handle exceptions and inspect their type/value without
// resorting to costly rethrows. On the other hand, using them is more
// cumbersome than just using exceptions and exception futures.
//
// Not all exceptions are passed in this way, therefore the container
// does not allow all types of coordinator exceptions. On the other hand,
// an exception being listed here does not mean it is _always_ passed
// in an exception_container - it can be thrown in a regular fashion
// as well.
//
// It is advised to use this mechanism mainly for exceptions which can
// happen frequently, e.g. signalling timeouts, overloads or rate limits.
using coordinator_exception_container = utils::exception_container<
mutation_write_timeout_exception,
read_timeout_exception,
read_failure_exception,
rate_limit_exception
>;
template<typename T = void>
using coordinator_result = bo::result<T,
coordinator_exception_container,
utils::exception_container_throw_policy
>;
}