1 // Copyright 2016 gRPC authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef GRPC_SRC_CORE_LIB_CHANNEL_CHANNEL_STACK_BUILDER_IMPL_H 16 #define GRPC_SRC_CORE_LIB_CHANNEL_CHANNEL_STACK_BUILDER_IMPL_H 17 18 #include <grpc/support/port_platform.h> 19 20 #include "absl/status/statusor.h" 21 #include "src/core/lib/channel/channel_fwd.h" 22 #include "src/core/lib/channel/channel_stack_builder.h" 23 #include "src/core/util/ref_counted_ptr.h" 24 25 namespace grpc_core { 26 27 class Blackboard; 28 29 // Build a channel stack. 30 // Allows interested parties to add filters to the stack, and to query an 31 // in-progress build. 32 // Carries some useful context for the channel stack, such as a target string 33 // and a transport. 34 class ChannelStackBuilderImpl final : public ChannelStackBuilder { 35 public: 36 using ChannelStackBuilder::ChannelStackBuilder; 37 SetBlackboards(const Blackboard * old_blackboard,Blackboard * new_blackboard)38 void SetBlackboards(const Blackboard* old_blackboard, 39 Blackboard* new_blackboard) { 40 old_blackboard_ = old_blackboard; 41 new_blackboard_ = new_blackboard; 42 } 43 44 // Build the channel stack. 45 // After success, *result holds the new channel stack, 46 // prefix_bytes are allocated before the channel stack, 47 // initial_refs, destroy, destroy_arg are as per grpc_channel_stack_init 48 // On failure, *result is nullptr. 49 absl::StatusOr<RefCountedPtr<grpc_channel_stack>> Build() override; 50 51 private: 52 const Blackboard* old_blackboard_ = nullptr; 53 Blackboard* new_blackboard_ = nullptr; 54 }; 55 56 } // namespace grpc_core 57 58 #endif // GRPC_SRC_CORE_LIB_CHANNEL_CHANNEL_STACK_BUILDER_IMPL_H 59