Files
AzSuicideDataVisualization/.venv/Lib/site-packages/pyarrow/include/arrow/flight/client_middleware.h
2022-05-23 00:16:32 +04:00

74 lines
2.6 KiB
C++

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
// Interfaces for defining middleware for Flight clients. Currently
// experimental.
#pragma once
#include <memory>
#include "arrow/flight/middleware.h"
#include "arrow/flight/visibility.h" // IWYU pragma: keep
#include "arrow/status.h"
namespace arrow {
namespace flight {
/// \brief Client-side middleware for a call, instantiated per RPC.
///
/// Middleware should be fast and must be infallible: there is no way
/// to reject the call or report errors from the middleware instance.
class ARROW_FLIGHT_EXPORT ClientMiddleware {
public:
virtual ~ClientMiddleware() = default;
/// \brief A callback before headers are sent. Extra headers can be
/// added, but existing ones cannot be read.
virtual void SendingHeaders(AddCallHeaders* outgoing_headers) = 0;
/// \brief A callback when headers are received from the server.
virtual void ReceivedHeaders(const CallHeaders& incoming_headers) = 0;
/// \brief A callback after the call has completed.
virtual void CallCompleted(const Status& status) = 0;
};
/// \brief A factory for new middleware instances.
///
/// If added to a client, this will be called for each RPC (including
/// Handshake) to give the opportunity to intercept the call.
///
/// It is guaranteed that all client middleware methods are called
/// from the same thread that calls the RPC method implementation.
class ARROW_FLIGHT_EXPORT ClientMiddlewareFactory {
public:
virtual ~ClientMiddlewareFactory() = default;
/// \brief A callback for the start of a new call.
///
/// \param info Information about the call.
/// \param[out] middleware The middleware instance for this call. If
/// unset, will not add middleware to this call instance from
/// this factory.
virtual void StartCall(const CallInfo& info,
std::unique_ptr<ClientMiddleware>* middleware) = 0;
};
} // namespace flight
} // namespace arrow