mirror of https://github.com/grpc/grpc.git
The C based gRPC (C++, Python, Ruby, Objective-C, PHP, C#)
https://grpc.io/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
179 lines
5.7 KiB
179 lines
5.7 KiB
10 years ago
|
/*
|
||
|
*
|
||
|
* Copyright 2014, 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 __GRPCPP_STREAM_H__
|
||
|
#define __GRPCPP_STREAM_H__
|
||
|
|
||
|
#include <grpc++/stream_context_interface.h>
|
||
|
#include <grpc++/status.h>
|
||
|
#include <grpc/support/log.h>
|
||
|
|
||
|
namespace grpc {
|
||
|
|
||
|
// Common interface for all client side streaming.
|
||
|
class ClientStreamingInterface {
|
||
|
public:
|
||
|
virtual ~ClientStreamingInterface() {}
|
||
|
|
||
|
// Try to cancel the stream. Wait() still needs to be called to get the final
|
||
|
// status. Cancelling after the stream has finished has no effects.
|
||
|
virtual void Cancel() = 0;
|
||
|
|
||
|
// Wait until the stream finishes, and return the final status. When the
|
||
|
// client side declares it has no more message to send, either implicitly or
|
||
|
// by calling WritesDone, it needs to make sure there is no more message to
|
||
|
// be received from the server, either implicitly or by getting a false from
|
||
|
// a Read(). Otherwise, this implicitly cancels the stream.
|
||
|
virtual const Status& Wait() = 0;
|
||
|
};
|
||
|
|
||
|
// An interface that yields a sequence of R messages.
|
||
|
template <class R>
|
||
|
class ReaderInterface {
|
||
|
public:
|
||
|
virtual ~ReaderInterface() {}
|
||
|
|
||
|
// Blocking read a message and parse to msg. Returns true on success.
|
||
|
// The method returns false when there will be no more incoming messages,
|
||
|
// either because the other side has called WritesDone or the stream has
|
||
|
// failed (or been cancelled).
|
||
|
virtual bool Read(R* msg) = 0;
|
||
|
};
|
||
|
|
||
|
// An interface that can be fed a sequence of W messages.
|
||
|
template <class W>
|
||
|
class WriterInterface {
|
||
|
public:
|
||
|
virtual ~WriterInterface() {}
|
||
|
|
||
|
// Blocking write msg to the stream. Returns true on success.
|
||
|
// Returns false when the stream has been closed.
|
||
|
virtual bool Write(const W& msg) = 0;
|
||
|
};
|
||
|
|
||
|
template <class R>
|
||
|
class ClientReader : public ClientStreamingInterface,
|
||
|
public ReaderInterface<R> {
|
||
|
public:
|
||
|
// Blocking create a stream and write the first request out.
|
||
|
explicit ClientReader(StreamContextInterface* context) : context_(context) {
|
||
|
GPR_ASSERT(context_);
|
||
|
context_->Start(true);
|
||
|
context_->Write(context_->request(), true);
|
||
|
}
|
||
|
|
||
|
~ClientReader() { delete context_; }
|
||
|
|
||
|
virtual bool Read(R* msg) { return context_->Read(msg); }
|
||
|
|
||
|
virtual void Cancel() { context_->FinishStream(Status::Cancelled, true); }
|
||
|
|
||
|
virtual const Status& Wait() { return context_->Wait(); }
|
||
|
|
||
|
private:
|
||
|
StreamContextInterface* const context_;
|
||
|
};
|
||
|
|
||
|
template <class W>
|
||
|
class ClientWriter : public ClientStreamingInterface,
|
||
|
public WriterInterface<W> {
|
||
|
public:
|
||
|
// Blocking create a stream.
|
||
|
explicit ClientWriter(StreamContextInterface* context) : context_(context) {
|
||
|
GPR_ASSERT(context_);
|
||
|
context_->Start(false);
|
||
|
}
|
||
|
|
||
|
~ClientWriter() { delete context_; }
|
||
|
|
||
|
virtual bool Write(const W& msg) {
|
||
|
return context_->Write(const_cast<W*>(&msg), false);
|
||
|
}
|
||
|
|
||
|
virtual void WritesDone() { context_->Write(nullptr, true); }
|
||
|
|
||
|
virtual void Cancel() { context_->FinishStream(Status::Cancelled, true); }
|
||
|
|
||
|
// Read the final response and wait for the final status.
|
||
|
virtual const Status& Wait() {
|
||
|
bool success = context_->Read(context_->response());
|
||
|
if (!success) {
|
||
|
Cancel();
|
||
|
} else {
|
||
|
success = context_->Read(nullptr);
|
||
|
if (success) {
|
||
|
Cancel();
|
||
|
}
|
||
|
}
|
||
|
return context_->Wait();
|
||
|
}
|
||
|
|
||
|
private:
|
||
|
StreamContextInterface* const context_;
|
||
|
};
|
||
|
|
||
|
// Client-side interface for bi-directional streaming.
|
||
|
template <class W, class R>
|
||
|
class ClientReaderWriter : public ClientStreamingInterface,
|
||
|
public WriterInterface<W>,
|
||
|
public ReaderInterface<R> {
|
||
|
public:
|
||
|
// Blocking create a stream.
|
||
|
explicit ClientReaderWriter(StreamContextInterface* context)
|
||
|
: context_(context) {
|
||
|
GPR_ASSERT(context_);
|
||
|
context_->Start(false);
|
||
|
}
|
||
|
|
||
|
~ClientReaderWriter() { delete context_; }
|
||
|
|
||
|
virtual bool Read(R* msg) { return context_->Read(msg); }
|
||
|
|
||
|
virtual bool Write(const W& msg) {
|
||
|
return context_->Write(const_cast<W*>(&msg), false);
|
||
|
}
|
||
|
|
||
|
virtual void WritesDone() { context_->Write(nullptr, true); }
|
||
|
|
||
|
virtual void Cancel() { context_->FinishStream(Status::Cancelled, true); }
|
||
|
|
||
|
virtual const Status& Wait() { return context_->Wait(); }
|
||
|
|
||
|
private:
|
||
|
StreamContextInterface* const context_;
|
||
|
};
|
||
|
|
||
|
} // namespace grpc
|
||
|
|
||
|
#endif // __GRPCPP_STREAM_H__
|