caffe源码分析-layer_factory

浅浅的花香味﹌ 2022-05-09 11:28 172阅读 0赞

`caffe`中有许多的`layer`,在net中创建连接`layer`是通过工厂模式的方式创建，而不是每一个`new`然后连接。在net.cpp中创建layer方式如下：

`layers_.push_back(LayerRegistry<Dtype>::CreateLayer(layer_param));`

下面简要分析下`layer_factory`

template<typename Dtype>
    class LayerRegistry{
        
    public:
        // 函数指针Creator，返回Layer<Dtype>指针
        typedef shared_ptr<Layer<Dtype>> (*Creator)(const LayerParameter&);
        typedef std::map<string, Creator> CreatorRegistry;
    
        static CreatorRegistry& Registry() {
        
            static CreatorRegistry* g_registry_ = new CreatorRegistry();
            return *g_registry_;
        }
    
        // Adds a creator.
        static void AddCreator(const string& type, Creator creator) {
        
            CreatorRegistry& registry = Registry();
            LOG(INFO) << "AddCreator: " << type;
            registry[type] = creator;
        }
    
        // Get a layer using a LayerParameter.
        static shared_ptr<Layer<Dtype> > CreateLayer(const LayerParameter& param) {
        
    
            const string& type = param.type();
            CreatorRegistry& registry = Registry();
    
            CHECK_EQ(registry.count(type), 1) << "Unknown layer type: ";
            return registry[type](param);
        }
    private:
        // Layer registry should never be instantiated
        // everything is done with its static variables.
        LayerRegistry() {
        }
    };

结合宏定义以及模板特化创建的对应的注册类：

template <typename Dtype>
    class LayerRegisterer {
        
    public:
        LayerRegisterer(const string& type,
                      shared_ptr<Layer<Dtype>>(*creator)(const LayerParameter&))
        {
        
            LayerRegistry<Dtype>::AddCreator(type, creator);
        }
    };
    
    #define REGISTER_LAYER_CREATOR(type, creator)                                       \
      static LayerRegisterer<float> g_creator_f_##type(#type, creator<float>);     \
      static LayerRegisterer<double> g_creator_d_##type(#type, creator<double>)    \
    
    #define REGISTER_LAYER_CLASS(type)                                                     \
      template <typename Dtype>                                                              \
      shared_ptr<Layer<Dtype> > Creator_##type##Layer(const LayerParameter& param) \
      {                                                                                            \
        return shared_ptr<Layer<Dtype> >(new type##Layer<Dtype>(param));              \
      }                                                                                            \
      REGISTER_LAYER_CREATOR(type, Creator_##type##Layer)
        
    }

使用如下,例如输入层：

INSTANTIATE_CLASS(InputLayer);
    REGISTER_LAYER_CLASS(Input);