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/*
*
* Copyright 2016, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. 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 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef GRPCXX_IMPL_CODEGEN_FC_UNARY_H
#define GRPCXX_IMPL_CODEGEN_FC_UNARY_H
#include <grpc++/impl/codegen/call.h>
#include <grpc++/impl/codegen/completion_queue.h>
#include <grpc++/impl/codegen/core_codegen_interface.h>
#include <grpc++/impl/codegen/method_handler_impl.h>
#include <grpc++/impl/codegen/server_context.h>
namespace grpc {
/// A class to represent a flow-controlled unary call. This is something
/// of a hybrid between conventional unary and streaming. This is invoked
/// through a unary call on the client side, but the server responds to it
/// as though it were a single-ping-pong streaming call. The server can use
/// the \a NextMessageSize method to determine an upper-bound on the size of
/// the message.
/// A key difference relative to streaming: an FCUnary must have exactly 1 Read
/// and exactly 1 Write, in that order, to function correctly.
/// Otherwise, the RPC is in error.
template <class RequestType, class ResponseType>
class FCUnary GRPC_FINAL {
public:
FCUnary(Call* call, ServerContext* ctx): call_(call), ctx_(ctx), read_done_(false), write_done_(false) {}
~FCUnary() {}
bool NextMessageSize(uint32_t *sz) {
*sz = call_->max_message_size();
return true;
}
bool Read(RequestType *request) {
if (read_done_) {
return false;
}
read_done_ = true;
CallOpSet<CallOpRecvMessage<RequestType>> ops;
ops.RecvMessage(request);
call_->PerformOps(&ops);
return call_->cq()->Pluck(&ops) && ops.got_message;
}
bool Write(const ResponseType& response) {return Write(response, WriteOptions());}
bool Write(const ResponseType& response, const WriteOptions& options) {
if (write_done_ || !read_done_) {
return false;
}
write_done_ = true;
CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage> ops;
if (!ops.SendMessage(response, options).ok()) {
return false;
}
if (!ctx_->sent_initial_metadata_) {
ops.SendInitialMetadata(ctx_->initial_metadata_,
ctx_->initial_metadata_flags());
ctx_->sent_initial_metadata_ = true;
} else {
return false;
}
call_->PerformOps(&ops);
return call_->cq()->Pluck(&ops);
}
private:
Call* const call_;
ServerContext* const ctx_;
bool read_done_;
bool write_done_;
};
} // namespace grpc
#endif // GRPCXX_IMPL_CODEGEN_FC_UNARY_H
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