Initial checkin of gRPC to third_party/

third_party/grpc/include/grpc++/impl/codegen/sync_stream.h

+/*
+ *
+ * Copyright 2015-2016, 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_SYNC_STREAM_H
+#define GRPCXX_IMPL_CODEGEN_SYNC_STREAM_H
+
+#include <grpc++/impl/codegen/call.h>
+#include <grpc++/impl/codegen/channel_interface.h>
+#include <grpc++/impl/codegen/client_context.h>
+#include <grpc++/impl/codegen/completion_queue.h>
+#include <grpc++/impl/codegen/server_context.h>
+#include <grpc++/impl/codegen/service_type.h>
+#include <grpc++/impl/codegen/status.h>
+#include <grpc/impl/codegen/log.h>
+
+namespace grpc {
+
+/// Common interface for all synchronous client side streaming.
+class ClientStreamingInterface {
+ public:
+  virtual ~ClientStreamingInterface() {}
+
+  /// 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 \a 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 \a Read().
+  ///
+  /// This function will return either:
+  /// - when all incoming messages have been read and the server has returned
+  ///   status.
+  /// - OR when the server has returned a non-OK status.
+  virtual Status Finish() = 0;
+};
+
+/// An interface that yields a sequence of messages of type \a R.
+template <class R>
+class ReaderInterface {
+ public:
+  virtual ~ReaderInterface() {}
+
+  /// Blocking read a message and parse to \a msg. Returns \a true on success.
+  ///
+  /// \param[out] msg The read message.
+  ///
+  /// \return \a false when there will be no more incoming messages, either
+  /// because the other side has called \a WritesDone() or the stream has failed
+  /// (or been cancelled).
+  virtual bool Read(R* msg) = 0;
+};
+
+/// An interface that can be fed a sequence of messages of type \a W.
+template <class W>
+class WriterInterface {
+ public:
+  virtual ~WriterInterface() {}
+
+  /// Blocking write \a msg to the stream with options.
+  ///
+  /// \param msg The message to be written to the stream.
+  /// \param options Options affecting the write operation.
+  ///
+  /// \return \a true on success, \a false when the stream has been closed.
+  virtual bool Write(const W& msg, const WriteOptions& options) = 0;
+
+  /// Blocking write \a msg to the stream with default options.
+  ///
+  /// \param msg The message to be written to the stream.
+  ///
+  /// \return \a true on success, \a false when the stream has been closed.
+  inline bool Write(const W& msg) { return Write(msg, WriteOptions()); }
+};
+
+/// Client-side interface for streaming reads of message of type \a R.
+template <class R>
+class ClientReaderInterface : public ClientStreamingInterface,
+                              public ReaderInterface<R> {
+ public:
+  /// Blocking wait for initial metadata from server. The received metadata
+  /// can only be accessed after this call returns. Should only be called before
+  /// the first read. Calling this method is optional, and if it is not called
+  /// the metadata will be available in ClientContext after the first read.
+  virtual void WaitForInitialMetadata() = 0;
+};
+
+template <class R>
+class ClientReader GRPC_FINAL : public ClientReaderInterface<R> {
+ public:
+  /// Blocking create a stream and write the first request out.
+  template <class W>
+  ClientReader(ChannelInterface* channel, const RpcMethod& method,
+               ClientContext* context, const W& request)
+      : context_(context), call_(channel->CreateCall(method, context, &cq_)) {
+    CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage,
+              CallOpClientSendClose> ops;
+    ops.SendInitialMetadata(context->send_initial_metadata_);
+    // TODO(ctiller): don't assert
+    GPR_ASSERT(ops.SendMessage(request).ok());
+    ops.ClientSendClose();
+    call_.PerformOps(&ops);
+    cq_.Pluck(&ops);
+  }
+
+  void WaitForInitialMetadata() GRPC_OVERRIDE {
+    GPR_ASSERT(!context_->initial_metadata_received_);
+
+    CallOpSet<CallOpRecvInitialMetadata> ops;
+    ops.RecvInitialMetadata(context_);
+    call_.PerformOps(&ops);
+    cq_.Pluck(&ops);  /// status ignored
+  }
+
+  bool Read(R* msg) GRPC_OVERRIDE {
+    CallOpSet<CallOpRecvInitialMetadata, CallOpRecvMessage<R>> ops;
+    if (!context_->initial_metadata_received_) {
+      ops.RecvInitialMetadata(context_);
+    }
+    ops.RecvMessage(msg);
+    call_.PerformOps(&ops);
+    return cq_.Pluck(&ops) && ops.got_message;
+  }
+
+  Status Finish() GRPC_OVERRIDE {
+    CallOpSet<CallOpClientRecvStatus> ops;
+    Status status;
+    ops.ClientRecvStatus(context_, &status);
+    call_.PerformOps(&ops);
+    GPR_ASSERT(cq_.Pluck(&ops));
+    return status;
+  }
+
+ private:
+  ClientContext* context_;
+  CompletionQueue cq_;
+  Call call_;
+};
+
+/// Client-side interface for streaming writes of message of type \a W.
+template <class W>
+class ClientWriterInterface : public ClientStreamingInterface,
+                              public WriterInterface<W> {
+ public:
+  /// Half close writing from the client.
+  /// Block until writes are completed.
+  ///
+  /// \return Whether the writes were successful.
+  virtual bool WritesDone() = 0;
+};
+
+template <class W>
+class ClientWriter : public ClientWriterInterface<W> {
+ public:
+  /// Blocking create a stream.
+  template <class R>
+  ClientWriter(ChannelInterface* channel, const RpcMethod& method,
+               ClientContext* context, R* response)
+      : context_(context), call_(channel->CreateCall(method, context, &cq_)) {
+    finish_ops_.RecvMessage(response);
+
+    CallOpSet<CallOpSendInitialMetadata> ops;
+    ops.SendInitialMetadata(context->send_initial_metadata_);
+    call_.PerformOps(&ops);
+    cq_.Pluck(&ops);
+  }
+
+  void WaitForInitialMetadata() {
+    GPR_ASSERT(!context_->initial_metadata_received_);
+
+    CallOpSet<CallOpRecvInitialMetadata> ops;
+    ops.RecvInitialMetadata(context_);
+    call_.PerformOps(&ops);
+    cq_.Pluck(&ops);  // status ignored
+  }
+
+  using WriterInterface<W>::Write;
+  bool Write(const W& msg, const WriteOptions& options) GRPC_OVERRIDE {
+    CallOpSet<CallOpSendMessage> ops;
+    if (!ops.SendMessage(msg, options).ok()) {
+      return false;
+    }
+    call_.PerformOps(&ops);
+    return cq_.Pluck(&ops);
+  }
+
+  bool WritesDone() GRPC_OVERRIDE {
+    CallOpSet<CallOpClientSendClose> ops;
+    ops.ClientSendClose();
+    call_.PerformOps(&ops);
+    return cq_.Pluck(&ops);
+  }
+
+  /// Read the final response and wait for the final status.
+  Status Finish() GRPC_OVERRIDE {
+    Status status;
+    if (!context_->initial_metadata_received_) {
+      finish_ops_.RecvInitialMetadata(context_);
+    }
+    finish_ops_.ClientRecvStatus(context_, &status);
+    call_.PerformOps(&finish_ops_);
+    GPR_ASSERT(cq_.Pluck(&finish_ops_));
+    return status;
+  }
+
+ private:
+  ClientContext* context_;
+  CallOpSet<CallOpRecvInitialMetadata, CallOpGenericRecvMessage,
+            CallOpClientRecvStatus> finish_ops_;
+  CompletionQueue cq_;
+  Call call_;
+};
+
+/// Client-side interface for bi-directional streaming.
+template <class W, class R>
+class ClientReaderWriterInterface : public ClientStreamingInterface,
+                                    public WriterInterface<W>,
+                                    public ReaderInterface<R> {
+ public:
+  /// Blocking wait for initial metadata from server. The received metadata
+  /// can only be accessed after this call returns. Should only be called before
+  /// the first read. Calling this method is optional, and if it is not called
+  /// the metadata will be available in ClientContext after the first read.
+  virtual void WaitForInitialMetadata() = 0;
+
+  /// Block until writes are completed.
+  ///
+  /// \return Whether the writes were successful.
+  virtual bool WritesDone() = 0;
+};
+
+template <class W, class R>
+class ClientReaderWriter GRPC_FINAL : public ClientReaderWriterInterface<W, R> {
+ public:
+  /// Blocking create a stream.
+  ClientReaderWriter(ChannelInterface* channel, const RpcMethod& method,
+                     ClientContext* context)
+      : context_(context), call_(channel->CreateCall(method, context, &cq_)) {
+    CallOpSet<CallOpSendInitialMetadata> ops;
+    ops.SendInitialMetadata(context->send_initial_metadata_);
+    call_.PerformOps(&ops);
+    cq_.Pluck(&ops);
+  }
+
+  void WaitForInitialMetadata() GRPC_OVERRIDE {
+    GPR_ASSERT(!context_->initial_metadata_received_);
+
+    CallOpSet<CallOpRecvInitialMetadata> ops;
+    ops.RecvInitialMetadata(context_);
+    call_.PerformOps(&ops);
+    cq_.Pluck(&ops);  // status ignored
+  }
+
+  bool Read(R* msg) GRPC_OVERRIDE {
+    CallOpSet<CallOpRecvInitialMetadata, CallOpRecvMessage<R>> ops;
+    if (!context_->initial_metadata_received_) {
+      ops.RecvInitialMetadata(context_);
+    }
+    ops.RecvMessage(msg);
+    call_.PerformOps(&ops);
+    return cq_.Pluck(&ops) && ops.got_message;
+  }
+
+  using WriterInterface<W>::Write;
+  bool Write(const W& msg, const WriteOptions& options) GRPC_OVERRIDE {
+    CallOpSet<CallOpSendMessage> ops;
+    if (!ops.SendMessage(msg, options).ok()) return false;
+    call_.PerformOps(&ops);
+    return cq_.Pluck(&ops);
+  }
+
+  bool WritesDone() GRPC_OVERRIDE {
+    CallOpSet<CallOpClientSendClose> ops;
+    ops.ClientSendClose();
+    call_.PerformOps(&ops);
+    return cq_.Pluck(&ops);
+  }
+
+  Status Finish() GRPC_OVERRIDE {
+    CallOpSet<CallOpRecvInitialMetadata, CallOpClientRecvStatus> ops;
+    if (!context_->initial_metadata_received_) {
+      ops.RecvInitialMetadata(context_);
+    }
+    Status status;
+    ops.ClientRecvStatus(context_, &status);
+    call_.PerformOps(&ops);
+    GPR_ASSERT(cq_.Pluck(&ops));
+    return status;
+  }
+
+ private:
+  ClientContext* context_;
+  CompletionQueue cq_;
+  Call call_;
+};
+
+template <class R>
+class ServerReader GRPC_FINAL : public ReaderInterface<R> {
+ public:
+  ServerReader(Call* call, ServerContext* ctx) : call_(call), ctx_(ctx) {}
+
+  void SendInitialMetadata() {
+    GPR_ASSERT(!ctx_->sent_initial_metadata_);
+
+    CallOpSet<CallOpSendInitialMetadata> ops;
+    ops.SendInitialMetadata(ctx_->initial_metadata_);
+    ctx_->sent_initial_metadata_ = true;
+    call_->PerformOps(&ops);
+    call_->cq()->Pluck(&ops);
+  }
+
+  bool Read(R* msg) GRPC_OVERRIDE {
+    CallOpSet<CallOpRecvMessage<R>> ops;
+    ops.RecvMessage(msg);
+    call_->PerformOps(&ops);
+    return call_->cq()->Pluck(&ops) && ops.got_message;
+  }
+
+ private:
+  Call* const call_;
+  ServerContext* const ctx_;
+};
+
+template <class W>
+class ServerWriter GRPC_FINAL : public WriterInterface<W> {
+ public:
+  ServerWriter(Call* call, ServerContext* ctx) : call_(call), ctx_(ctx) {}
+
+  void SendInitialMetadata() {
+    GPR_ASSERT(!ctx_->sent_initial_metadata_);
+
+    CallOpSet<CallOpSendInitialMetadata> ops;
+    ops.SendInitialMetadata(ctx_->initial_metadata_);
+    ctx_->sent_initial_metadata_ = true;
+    call_->PerformOps(&ops);
+    call_->cq()->Pluck(&ops);
+  }
+
+  using WriterInterface<W>::Write;
+  bool Write(const W& msg, const WriteOptions& options) GRPC_OVERRIDE {
+    CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage> ops;
+    if (!ops.SendMessage(msg, options).ok()) {
+      return false;
+    }
+    if (!ctx_->sent_initial_metadata_) {
+      ops.SendInitialMetadata(ctx_->initial_metadata_);
+      ctx_->sent_initial_metadata_ = true;
+    }
+    call_->PerformOps(&ops);
+    return call_->cq()->Pluck(&ops);
+  }
+
+ private:
+  Call* const call_;
+  ServerContext* const ctx_;
+};
+
+/// Server-side interface for bi-directional streaming.
+template <class W, class R>
+class ServerReaderWriter GRPC_FINAL : public WriterInterface<W>,
+                                      public ReaderInterface<R> {
+ public:
+  ServerReaderWriter(Call* call, ServerContext* ctx) : call_(call), ctx_(ctx) {}
+
+  void SendInitialMetadata() {
+    GPR_ASSERT(!ctx_->sent_initial_metadata_);
+
+    CallOpSet<CallOpSendInitialMetadata> ops;
+    ops.SendInitialMetadata(ctx_->initial_metadata_);
+    ctx_->sent_initial_metadata_ = true;
+    call_->PerformOps(&ops);
+    call_->cq()->Pluck(&ops);
+  }
+
+  bool Read(R* msg) GRPC_OVERRIDE {
+    CallOpSet<CallOpRecvMessage<R>> ops;
+    ops.RecvMessage(msg);
+    call_->PerformOps(&ops);
+    return call_->cq()->Pluck(&ops) && ops.got_message;
+  }
+
+  using WriterInterface<W>::Write;
+  bool Write(const W& msg, const WriteOptions& options) GRPC_OVERRIDE {
+    CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage> ops;
+    if (!ops.SendMessage(msg, options).ok()) {
+      return false;
+    }
+    if (!ctx_->sent_initial_metadata_) {
+      ops.SendInitialMetadata(ctx_->initial_metadata_);
+      ctx_->sent_initial_metadata_ = true;
+    }
+    call_->PerformOps(&ops);
+    return call_->cq()->Pluck(&ops);
+  }
+
+ private:
+  Call* const call_;
+  ServerContext* const ctx_;
+};
+
+}  // namespace grpc
+
+#endif  // GRPCXX_IMPL_CODEGEN_SYNC_STREAM_H