1 // 2 // 3 // Copyright 2021 gRPC authors. 4 // 5 // Licensed under the Apache License, Version 2.0 (the "License"); 6 // you may not use this file except in compliance with the License. 7 // You may obtain a copy of the License at 8 // 9 // http://www.apache.org/licenses/LICENSE-2.0 10 // 11 // Unless required by applicable law or agreed to in writing, software 12 // distributed under the License is distributed on an "AS IS" BASIS, 13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 // See the License for the specific language governing permissions and 15 // limitations under the License. 16 // 17 // 18 19 #ifndef GRPC_SRC_CORE_EXT_XDS_XDS_CHANNEL_STACK_MODIFIER_H 20 #define GRPC_SRC_CORE_EXT_XDS_XDS_CHANNEL_STACK_MODIFIER_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include <utility> 25 #include <vector> 26 27 #include "absl/strings/string_view.h" 28 29 #include <grpc/grpc.h> 30 31 #include "src/core/lib/channel/channel_fwd.h" 32 #include "src/core/lib/channel/channel_stack_builder.h" 33 #include "src/core/lib/gpr/useful.h" 34 #include "src/core/lib/gprpp/ref_counted.h" 35 #include "src/core/lib/gprpp/ref_counted_ptr.h" 36 37 namespace grpc_core { 38 39 // XdsChannelStackModifier allows for inserting xDS HTTP filters into the 40 // channel stack. It is registered to mutate the 41 // `ChannelStackBuilder` object via 42 // ChannelInit::Builder::RegisterStage. 43 class XdsChannelStackModifier : public RefCounted<XdsChannelStackModifier> { 44 public: XdsChannelStackModifier(std::vector<const grpc_channel_filter * > filters)45 explicit XdsChannelStackModifier( 46 std::vector<const grpc_channel_filter*> filters) 47 : filters_(std::move(filters)) {} 48 // Returns true on success, false otherwise. 49 bool ModifyChannelStack(ChannelStackBuilder* builder); 50 grpc_arg MakeChannelArg() const; 51 static RefCountedPtr<XdsChannelStackModifier> GetFromChannelArgs( 52 const grpc_channel_args& args); 53 static absl::string_view ChannelArgName(); ChannelArgsCompare(const XdsChannelStackModifier * a,const XdsChannelStackModifier * b)54 static int ChannelArgsCompare(const XdsChannelStackModifier* a, 55 const XdsChannelStackModifier* b) { 56 return QsortCompare(a, b); 57 } 58 59 private: 60 std::vector<const grpc_channel_filter*> filters_; 61 }; 62 63 } // namespace grpc_core 64 65 #endif // GRPC_SRC_CORE_EXT_XDS_XDS_CHANNEL_STACK_MODIFIER_H 66