1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_FILTER_CHAIN_H_ 6 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_FILTER_CHAIN_H_ 7 8 #include <vector> 9 10 #include "mojo/public/cpp/bindings/message.h" 11 #include "mojo/public/cpp/bindings/message_filter.h" 12 #include "mojo/public/cpp/system/macros.h" 13 14 namespace mojo { 15 namespace internal { 16 17 class FilterChain { 18 MOJO_MOVE_ONLY_TYPE_FOR_CPP_03(FilterChain, RValue) 19 20 public: 21 // Doesn't take ownership of |sink|. Therefore |sink| has to stay alive while 22 // this object is alive. 23 explicit FilterChain(MessageReceiver* sink = NULL); 24 25 // Move-only constructor and operator=. 26 FilterChain(RValue other); 27 FilterChain& operator=(RValue other); 28 29 ~FilterChain(); 30 31 template <typename FilterType> 32 inline void Append(); 33 34 // Doesn't take ownership of |sink|. Therefore |sink| has to stay alive while 35 // this object is alive. 36 void SetSink(MessageReceiver* sink); 37 38 // Returns a receiver to accept messages. Messages flow through all filters in 39 // the same order as they were appended to the chain. If all filters allow a 40 // message to pass, it will be forwarded to |sink_|. 41 // The returned value is invalidated when this object goes away. 42 MessageReceiver* GetHead(); 43 44 private: 45 // Owned by this object. 46 std::vector<MessageFilter*> filters_; 47 48 MessageReceiver* sink_; 49 }; 50 51 template <typename FilterType> 52 inline void FilterChain::Append() { 53 FilterType* filter = new FilterType(sink_); 54 if (!filters_.empty()) 55 filters_.back()->set_sink(filter); 56 filters_.push_back(filter); 57 } 58 59 template <> 60 inline void FilterChain::Append<PassThroughFilter>() { 61 } 62 63 } // namespace internal 64 } // namespace mojo 65 66 #endif // MOJO_PUBLIC_CPP_BINDINGS_LIB_FILTER_CHAIN_H_ 67
