Initial checkin of gRPC to third_party/

third_party/grpc/include/grpc++/impl/codegen/call.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_CALL_H
+#define GRPCXX_IMPL_CODEGEN_CALL_H
+
+#include <functional>
+#include <memory>
+#include <map>
+#include <cstring>
+
+#include <grpc/impl/codegen/alloc.h>
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc++/impl/codegen/client_context.h>
+#include <grpc++/impl/codegen/call_hook.h>
+#include <grpc++/impl/codegen/completion_queue_tag.h>
+#include <grpc++/impl/codegen/serialization_traits.h>
+#include <grpc++/impl/codegen/config.h>
+#include <grpc++/impl/codegen/status.h>
+
+struct grpc_byte_buffer;
+
+namespace grpc {
+
+class ByteBuffer;
+class Call;
+class CallHook;
+class CompletionQueue;
+
+void FillMetadataMap(
+    grpc_metadata_array* arr,
+    std::multimap<grpc::string_ref, grpc::string_ref>* metadata);
+grpc_metadata* FillMetadataArray(
+    const std::multimap<grpc::string, grpc::string>& metadata);
+
+/// Per-message write options.
+class WriteOptions {
+ public:
+  WriteOptions() : flags_(0) {}
+  WriteOptions(const WriteOptions& other) : flags_(other.flags_) {}
+
+  /// Clear all flags.
+  inline void Clear() { flags_ = 0; }
+
+  /// Returns raw flags bitset.
+  inline uint32_t flags() const { return flags_; }
+
+  /// Sets flag for the disabling of compression for the next message write.
+  ///
+  /// \sa GRPC_WRITE_NO_COMPRESS
+  inline WriteOptions& set_no_compression() {
+    SetBit(GRPC_WRITE_NO_COMPRESS);
+    return *this;
+  }
+
+  /// Clears flag for the disabling of compression for the next message write.
+  ///
+  /// \sa GRPC_WRITE_NO_COMPRESS
+  inline WriteOptions& clear_no_compression() {
+    ClearBit(GRPC_WRITE_NO_COMPRESS);
+    return *this;
+  }
+
+  /// Get value for the flag indicating whether compression for the next
+  /// message write is forcefully disabled.
+  ///
+  /// \sa GRPC_WRITE_NO_COMPRESS
+  inline bool get_no_compression() const {
+    return GetBit(GRPC_WRITE_NO_COMPRESS);
+  }
+
+  /// Sets flag indicating that the write may be buffered and need not go out on
+  /// the wire immediately.
+  ///
+  /// \sa GRPC_WRITE_BUFFER_HINT
+  inline WriteOptions& set_buffer_hint() {
+    SetBit(GRPC_WRITE_BUFFER_HINT);
+    return *this;
+  }
+
+  /// Clears flag indicating that the write may be buffered and need not go out
+  /// on the wire immediately.
+  ///
+  /// \sa GRPC_WRITE_BUFFER_HINT
+  inline WriteOptions& clear_buffer_hint() {
+    ClearBit(GRPC_WRITE_BUFFER_HINT);
+    return *this;
+  }
+
+  /// Get value for the flag indicating that the write may be buffered and need
+  /// not go out on the wire immediately.
+  ///
+  /// \sa GRPC_WRITE_BUFFER_HINT
+  inline bool get_buffer_hint() const { return GetBit(GRPC_WRITE_BUFFER_HINT); }
+
+  WriteOptions& operator=(const WriteOptions& rhs) {
+    flags_ = rhs.flags_;
+    return *this;
+  }
+
+ private:
+  void SetBit(const uint32_t mask) { flags_ |= mask; }
+
+  void ClearBit(const uint32_t mask) { flags_ &= ~mask; }
+
+  bool GetBit(const uint32_t mask) const { return (flags_ & mask) != 0; }
+
+  uint32_t flags_;
+};
+
+/// Default argument for CallOpSet. I is unused by the class, but can be
+/// used for generating multiple names for the same thing.
+template <int I>
+class CallNoOp {
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {}
+  void FinishOp(bool* status, int max_message_size) {}
+};
+
+class CallOpSendInitialMetadata {
+ public:
+  CallOpSendInitialMetadata() : send_(false) {}
+
+  void SendInitialMetadata(
+      const std::multimap<grpc::string, grpc::string>& metadata) {
+    send_ = true;
+    initial_metadata_count_ = metadata.size();
+    initial_metadata_ = FillMetadataArray(metadata);
+  }
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (!send_) return;
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_SEND_INITIAL_METADATA;
+    op->flags = 0;
+    op->reserved = NULL;
+    op->data.send_initial_metadata.count = initial_metadata_count_;
+    op->data.send_initial_metadata.metadata = initial_metadata_;
+  }
+  void FinishOp(bool* status, int max_message_size) {
+    if (!send_) return;
+    gpr_free(initial_metadata_);
+    send_ = false;
+  }
+
+  bool send_;
+  size_t initial_metadata_count_;
+  grpc_metadata* initial_metadata_;
+};
+
+class CallOpSendMessage {
+ public:
+  CallOpSendMessage() : send_buf_(nullptr), own_buf_(false) {}
+
+  /// Send \a message using \a options for the write. The \a options are cleared
+  /// after use.
+  template <class M>
+  Status SendMessage(const M& message,
+                     const WriteOptions& options) GRPC_MUST_USE_RESULT;
+
+  template <class M>
+  Status SendMessage(const M& message) GRPC_MUST_USE_RESULT;
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (send_buf_ == nullptr) return;
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_SEND_MESSAGE;
+    op->flags = write_options_.flags();
+    op->reserved = NULL;
+    op->data.send_message = send_buf_;
+    // Flags are per-message: clear them after use.
+    write_options_.Clear();
+  }
+  void FinishOp(bool* status, int max_message_size) {
+    if (own_buf_) grpc_byte_buffer_destroy(send_buf_);
+    send_buf_ = nullptr;
+  }
+
+ private:
+  grpc_byte_buffer* send_buf_;
+  WriteOptions write_options_;
+  bool own_buf_;
+};
+
+template <class M>
+Status CallOpSendMessage::SendMessage(const M& message,
+                                      const WriteOptions& options) {
+  write_options_ = options;
+  return SerializationTraits<M>::Serialize(message, &send_buf_, &own_buf_);
+}
+
+template <class M>
+Status CallOpSendMessage::SendMessage(const M& message) {
+  return SendMessage(message, WriteOptions());
+}
+
+template <class R>
+class CallOpRecvMessage {
+ public:
+  CallOpRecvMessage() : got_message(false), message_(nullptr) {}
+
+  void RecvMessage(R* message) { message_ = message; }
+
+  bool got_message;
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (message_ == nullptr) return;
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_RECV_MESSAGE;
+    op->flags = 0;
+    op->reserved = NULL;
+    op->data.recv_message = &recv_buf_;
+  }
+
+  void FinishOp(bool* status, int max_message_size) {
+    if (message_ == nullptr) return;
+    if (recv_buf_) {
+      if (*status) {
+        got_message = true;
+        *status = SerializationTraits<R>::Deserialize(recv_buf_, message_,
+                                                      max_message_size).ok();
+      } else {
+        got_message = false;
+        grpc_byte_buffer_destroy(recv_buf_);
+      }
+    } else {
+      got_message = false;
+      *status = false;
+    }
+    message_ = nullptr;
+  }
+
+ private:
+  R* message_;
+  grpc_byte_buffer* recv_buf_;
+};
+
+namespace CallOpGenericRecvMessageHelper {
+class DeserializeFunc {
+ public:
+  virtual Status Deserialize(grpc_byte_buffer* buf, int max_message_size) = 0;
+  virtual ~DeserializeFunc() {}
+};
+
+template <class R>
+class DeserializeFuncType GRPC_FINAL : public DeserializeFunc {
+ public:
+  DeserializeFuncType(R* message) : message_(message) {}
+  Status Deserialize(grpc_byte_buffer* buf,
+                     int max_message_size) GRPC_OVERRIDE {
+    return SerializationTraits<R>::Deserialize(buf, message_, max_message_size);
+  }
+
+  ~DeserializeFuncType() override {}
+
+ private:
+  R* message_;  // Not a managed pointer because management is external to this
+};
+}  // namespace CallOpGenericRecvMessageHelper
+
+class CallOpGenericRecvMessage {
+ public:
+  CallOpGenericRecvMessage() : got_message(false) {}
+
+  template <class R>
+  void RecvMessage(R* message) {
+    deserialize_.reset(
+        new CallOpGenericRecvMessageHelper::DeserializeFuncType<R>(message));
+  }
+
+  bool got_message;
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (!deserialize_) return;
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_RECV_MESSAGE;
+    op->flags = 0;
+    op->reserved = NULL;
+    op->data.recv_message = &recv_buf_;
+  }
+
+  void FinishOp(bool* status, int max_message_size) {
+    if (!deserialize_) return;
+    if (recv_buf_) {
+      if (*status) {
+        got_message = true;
+        *status = deserialize_->Deserialize(recv_buf_, max_message_size).ok();
+      } else {
+        got_message = false;
+        grpc_byte_buffer_destroy(recv_buf_);
+      }
+    } else {
+      got_message = false;
+      *status = false;
+    }
+    deserialize_.reset();
+  }
+
+ private:
+  std::unique_ptr<CallOpGenericRecvMessageHelper::DeserializeFunc> deserialize_;
+  grpc_byte_buffer* recv_buf_;
+};
+
+class CallOpClientSendClose {
+ public:
+  CallOpClientSendClose() : send_(false) {}
+
+  void ClientSendClose() { send_ = true; }
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (!send_) return;
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
+    op->flags = 0;
+    op->reserved = NULL;
+  }
+  void FinishOp(bool* status, int max_message_size) { send_ = false; }
+
+ private:
+  bool send_;
+};
+
+class CallOpServerSendStatus {
+ public:
+  CallOpServerSendStatus() : send_status_available_(false) {}
+
+  void ServerSendStatus(
+      const std::multimap<grpc::string, grpc::string>& trailing_metadata,
+      const Status& status) {
+    trailing_metadata_count_ = trailing_metadata.size();
+    trailing_metadata_ = FillMetadataArray(trailing_metadata);
+    send_status_available_ = true;
+    send_status_code_ = static_cast<grpc_status_code>(status.error_code());
+    send_status_details_ = status.error_message();
+  }
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (!send_status_available_) return;
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
+    op->data.send_status_from_server.trailing_metadata_count =
+        trailing_metadata_count_;
+    op->data.send_status_from_server.trailing_metadata = trailing_metadata_;
+    op->data.send_status_from_server.status = send_status_code_;
+    op->data.send_status_from_server.status_details =
+        send_status_details_.empty() ? nullptr : send_status_details_.c_str();
+    op->flags = 0;
+    op->reserved = NULL;
+  }
+
+  void FinishOp(bool* status, int max_message_size) {
+    if (!send_status_available_) return;
+    gpr_free(trailing_metadata_);
+    send_status_available_ = false;
+  }
+
+ private:
+  bool send_status_available_;
+  grpc_status_code send_status_code_;
+  grpc::string send_status_details_;
+  size_t trailing_metadata_count_;
+  grpc_metadata* trailing_metadata_;
+};
+
+class CallOpRecvInitialMetadata {
+ public:
+  CallOpRecvInitialMetadata() : recv_initial_metadata_(nullptr) {}
+
+  void RecvInitialMetadata(ClientContext* context) {
+    context->initial_metadata_received_ = true;
+    recv_initial_metadata_ = &context->recv_initial_metadata_;
+  }
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (!recv_initial_metadata_) return;
+    memset(&recv_initial_metadata_arr_, 0, sizeof(recv_initial_metadata_arr_));
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_RECV_INITIAL_METADATA;
+    op->data.recv_initial_metadata = &recv_initial_metadata_arr_;
+    op->flags = 0;
+    op->reserved = NULL;
+  }
+  void FinishOp(bool* status, int max_message_size) {
+    if (recv_initial_metadata_ == nullptr) return;
+    FillMetadataMap(&recv_initial_metadata_arr_, recv_initial_metadata_);
+    recv_initial_metadata_ = nullptr;
+  }
+
+ private:
+  std::multimap<grpc::string_ref, grpc::string_ref>* recv_initial_metadata_;
+  grpc_metadata_array recv_initial_metadata_arr_;
+};
+
+class CallOpClientRecvStatus {
+ public:
+  CallOpClientRecvStatus() : recv_status_(nullptr) {}
+
+  void ClientRecvStatus(ClientContext* context, Status* status) {
+    recv_trailing_metadata_ = &context->trailing_metadata_;
+    recv_status_ = status;
+  }
+
+ protected:
+  void AddOp(grpc_op* ops, size_t* nops) {
+    if (recv_status_ == nullptr) return;
+    memset(&recv_trailing_metadata_arr_, 0,
+           sizeof(recv_trailing_metadata_arr_));
+    status_details_ = nullptr;
+    status_details_capacity_ = 0;
+    grpc_op* op = &ops[(*nops)++];
+    op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
+    op->data.recv_status_on_client.trailing_metadata =
+        &recv_trailing_metadata_arr_;
+    op->data.recv_status_on_client.status = &status_code_;
+    op->data.recv_status_on_client.status_details = &status_details_;
+    op->data.recv_status_on_client.status_details_capacity =
+        &status_details_capacity_;
+    op->flags = 0;
+    op->reserved = NULL;
+  }
+
+  void FinishOp(bool* status, int max_message_size) {
+    if (recv_status_ == nullptr) return;
+    FillMetadataMap(&recv_trailing_metadata_arr_, recv_trailing_metadata_);
+    *recv_status_ = Status(
+        static_cast<StatusCode>(status_code_),
+        status_details_ ? grpc::string(status_details_) : grpc::string());
+    gpr_free(status_details_);
+    recv_status_ = nullptr;
+  }
+
+ private:
+  std::multimap<grpc::string_ref, grpc::string_ref>* recv_trailing_metadata_;
+  Status* recv_status_;
+  grpc_metadata_array recv_trailing_metadata_arr_;
+  grpc_status_code status_code_;
+  char* status_details_;
+  size_t status_details_capacity_;
+};
+
+/// An abstract collection of CallOpSet's, to be used whenever
+/// CallOpSet objects must be thought of as a group. Each member
+/// of the group should have a shared_ptr back to the collection,
+/// as will the object that instantiates the collection, allowing
+/// for automatic ref-counting. In practice, any actual use should
+/// derive from this base class. This is specifically necessary if
+/// some of the CallOpSet's in the collection are "Sneaky" and don't
+/// report back to the C++ layer CQ operations
+class CallOpSetCollectionInterface
+    : public std::enable_shared_from_this<CallOpSetCollectionInterface> {};
+
+/// An abstract collection of call ops, used to generate the
+/// grpc_call_op structure to pass down to the lower layers,
+/// and as it is-a CompletionQueueTag, also massages the final
+/// completion into the correct form for consumption in the C++
+/// API.
+class CallOpSetInterface : public CompletionQueueTag {
+ public:
+  CallOpSetInterface() : max_message_size_(0) {}
+  /// Fills in grpc_op, starting from ops[*nops] and moving
+  /// upwards.
+  virtual void FillOps(grpc_op* ops, size_t* nops) = 0;
+
+  void set_max_message_size(int max_message_size) {
+    max_message_size_ = max_message_size;
+  }
+
+  /// Mark this as belonging to a collection if needed
+  void SetCollection(std::shared_ptr<CallOpSetCollectionInterface> collection) {
+    collection_ = collection;
+  }
+
+ protected:
+  int max_message_size_;
+  std::shared_ptr<CallOpSetCollectionInterface> collection_;
+};
+
+/// Primary implementaiton of CallOpSetInterface.
+/// Since we cannot use variadic templates, we declare slots up to
+/// the maximum count of ops we'll need in a set. We leverage the
+/// empty base class optimization to slim this class (especially
+/// when there are many unused slots used). To avoid duplicate base classes,
+/// the template parmeter for CallNoOp is varied by argument position.
+template <class Op1 = CallNoOp<1>, class Op2 = CallNoOp<2>,
+          class Op3 = CallNoOp<3>, class Op4 = CallNoOp<4>,
+          class Op5 = CallNoOp<5>, class Op6 = CallNoOp<6>>
+class CallOpSet : public CallOpSetInterface,
+                  public Op1,
+                  public Op2,
+                  public Op3,
+                  public Op4,
+                  public Op5,
+                  public Op6 {
+ public:
+  CallOpSet() : return_tag_(this) {}
+  void FillOps(grpc_op* ops, size_t* nops) GRPC_OVERRIDE {
+    this->Op1::AddOp(ops, nops);
+    this->Op2::AddOp(ops, nops);
+    this->Op3::AddOp(ops, nops);
+    this->Op4::AddOp(ops, nops);
+    this->Op5::AddOp(ops, nops);
+    this->Op6::AddOp(ops, nops);
+  }
+
+  bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE {
+    this->Op1::FinishOp(status, max_message_size_);
+    this->Op2::FinishOp(status, max_message_size_);
+    this->Op3::FinishOp(status, max_message_size_);
+    this->Op4::FinishOp(status, max_message_size_);
+    this->Op5::FinishOp(status, max_message_size_);
+    this->Op6::FinishOp(status, max_message_size_);
+    *tag = return_tag_;
+    collection_.reset();  // drop the ref at this point
+    return true;
+  }
+
+  void set_output_tag(void* return_tag) { return_tag_ = return_tag; }
+
+ private:
+  void* return_tag_;
+};
+
+/// A CallOpSet that does not post completions to the completion queue.
+///
+/// Allows hiding some completions that the C core must generate from
+/// C++ users.
+template <class Op1 = CallNoOp<1>, class Op2 = CallNoOp<2>,
+          class Op3 = CallNoOp<3>, class Op4 = CallNoOp<4>,
+          class Op5 = CallNoOp<5>, class Op6 = CallNoOp<6>>
+class SneakyCallOpSet : public CallOpSet<Op1, Op2, Op3, Op4, Op5, Op6> {
+ public:
+  bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE {
+    typedef CallOpSet<Op1, Op2, Op3, Op4, Op5, Op6> Base;
+    return Base::FinalizeResult(tag, status) && false;
+  }
+};
+
+// Straightforward wrapping of the C call object
+class Call GRPC_FINAL {
+ public:
+  /* call is owned by the caller */
+  Call(grpc_call* call, CallHook* call_hook_, CompletionQueue* cq);
+  Call(grpc_call* call, CallHook* call_hook_, CompletionQueue* cq,
+       int max_message_size);
+
+  void PerformOps(CallOpSetInterface* ops);
+
+  grpc_call* call() { return call_; }
+  CompletionQueue* cq() { return cq_; }
+
+  int max_message_size() { return max_message_size_; }
+
+ private:
+  CallHook* call_hook_;
+  CompletionQueue* cq_;
+  grpc_call* call_;
+  int max_message_size_;
+};
+
+}  // namespace grpc
+
+#endif  // GRPCXX_IMPL_CODEGEN_CALL_H