dnn: added "hidden" experimental namespace

Main purpose of this namespace is to avoid using of incompatible
binaries that will cause applications crashes.

This additional namespace will not impact "Source code API".
This change allows to maintain ABI checks (with easy filtering out).

modules/dnn/src/caffe/caffe_importer.cpp

@@ -40,8 +40,6 @@
 //M*/
 
 #include "../precomp.hpp"
-using namespace cv;
-using namespace cv::dnn;
 
 #if HAVE_PROTOBUF
 #include "caffe.pb.h"
@@ -54,7 +52,13 @@ using namespace cv::dnn;
 #include <google/protobuf/text_format.h>
 #include <google/protobuf/io/zero_copy_stream_impl.h>
 #include "caffe_io.hpp"
+#endif
 
+namespace cv {
+namespace dnn {
+CV__DNN_EXPERIMENTAL_NS_BEGIN
+
+#ifdef HAVE_PROTOBUF
 using ::google::protobuf::RepeatedField;
 using ::google::protobuf::RepeatedPtrField;
 using ::google::protobuf::Message;
@@ -357,14 +361,14 @@ public:
 
 }
 
-Ptr<Importer> cv::dnn::createCaffeImporter(const String &prototxt, const String &caffeModel)
+Ptr<Importer> createCaffeImporter(const String &prototxt, const String &caffeModel)
 {
     return Ptr<Importer>(new CaffeImporter(prototxt.c_str(), caffeModel.c_str()));
 }
 
 #else //HAVE_PROTOBUF
 
-Ptr<Importer> cv::dnn::createCaffeImporter(const String&, const String&)
+Ptr<Importer> createCaffeImporter(const String&, const String&)
 {
     CV_Error(cv::Error::StsNotImplemented, "libprotobuf required to import data from Caffe models");
     return Ptr<Importer>();
@@ -372,7 +376,7 @@ Ptr<Importer> cv::dnn::createCaffeImporter(const String&, const String&)
 
 #endif //HAVE_PROTOBUF
 
-Net cv::dnn::readNetFromCaffe(const String &prototxt, const String &caffeModel /*= String()*/)
+Net readNetFromCaffe(const String &prototxt, const String &caffeModel /*= String()*/)
 {
     Ptr<Importer> caffeImporter = createCaffeImporter(prototxt, caffeModel);
     Net net;
@@ -380,3 +384,6 @@ Net cv::dnn::readNetFromCaffe(const String &prototxt, const String &caffeModel /
         caffeImporter->populateNet(net);
     return net;
 }
+
+CV__DNN_EXPERIMENTAL_NS_END
+}} // namespace

modules/dnn/src/dnn.cpp

@@ -50,8 +50,9 @@
 #include <opencv2/dnn/shape_utils.hpp>
 #include <opencv2/imgproc.hpp>
 
-using namespace cv;
-using namespace cv::dnn;
+namespace cv {
+namespace dnn {
+CV__DNN_EXPERIMENTAL_NS_BEGIN
 
 using std::vector;
 using std::map;
@@ -74,11 +75,6 @@ namespace
     };
 }
 
-namespace cv
-{
-namespace dnn
-{
-
 template<typename T>
 static String toString(const T &v)
 {
@@ -2030,5 +2026,5 @@ BackendWrapper::BackendWrapper(const Ptr<BackendWrapper>& base, const MatShape&
 
 BackendWrapper::~BackendWrapper() {}
 
-}
-}
+CV__DNN_EXPERIMENTAL_NS_END
+}} // namespace

modules/dnn/src/init.cpp

@@ -42,10 +42,9 @@
 #include "precomp.hpp"
 #include <opencv2/dnn/layer.details.hpp>
 
-namespace cv
-{
-namespace dnn
-{
+namespace cv {
+namespace dnn {
+CV__DNN_EXPERIMENTAL_NS_BEGIN
 
 static Mutex* __initialization_mutex = NULL;
 Mutex& getInitializationMutex()
@@ -98,4 +97,5 @@ void initializeLayerFactory()
     CV_DNN_REGISTER_LAYER_CLASS(Scale,          ScaleLayer);
 }
 
-}} //namespace
+CV__DNN_EXPERIMENTAL_NS_END
+}} // namespace

modules/dnn/src/precomp.hpp

@@ -45,6 +45,8 @@
 #include <opencv2/dnn/all_layers.hpp>
 
 namespace cv { namespace dnn {
+CV__DNN_EXPERIMENTAL_NS_BEGIN
 Mutex& getInitializationMutex();
 void initializeLayerFactory();
+CV__DNN_EXPERIMENTAL_NS_END
 }} // namespace

modules/dnn/src/tensorflow/tf_importer.cpp

@@ -10,8 +10,6 @@ Implementation of Tensorflow models parser
 */
 
 #include "../precomp.hpp"
-using namespace cv;
-using namespace cv::dnn;
 
 #if HAVE_PROTOBUF
 #include "graph.pb.h"
@@ -24,6 +22,13 @@ using namespace cv::dnn;
 #include <google/protobuf/text_format.h>
 #include <google/protobuf/io/zero_copy_stream_impl.h>
 #include "tf_io.hpp"
+#endif
+
+namespace cv {
+namespace dnn {
+CV__DNN_EXPERIMENTAL_NS_BEGIN
+
+#if HAVE_PROTOBUF
 
 using ::google::protobuf::RepeatedField;
 using ::google::protobuf::RepeatedPtrField;
@@ -734,14 +739,14 @@ void TFImporter::populateNet(Net dstNet)
 
 } // namespace
 
-Ptr<Importer> cv::dnn::createTensorflowImporter(const String &model)
+Ptr<Importer> createTensorflowImporter(const String &model)
 {
     return Ptr<Importer>(new TFImporter(model.c_str()));
 }
 
 #else //HAVE_PROTOBUF
 
-Ptr<Importer> cv::dnn::createTensorflowImporter(const String&)
+Ptr<Importer> createTensorflowImporter(const String&)
 {
     CV_Error(cv::Error::StsNotImplemented, "libprotobuf required to import data from TensorFlow models");
     return Ptr<Importer>();
@@ -749,7 +754,7 @@ Ptr<Importer> cv::dnn::createTensorflowImporter(const String&)
 
 #endif //HAVE_PROTOBUF
 
-Net cv::dnn::readNetFromTensorflow(const String &model)
+Net readNetFromTensorflow(const String &model)
 {
     Ptr<Importer> importer = createTensorflowImporter(model);
     Net net;
@@ -757,3 +762,6 @@ Net cv::dnn::readNetFromTensorflow(const String &model)
         importer->populateNet(net);
     return net;
 }
+
+CV__DNN_EXPERIMENTAL_NS_END
+}} // namespace

modules/dnn/src/torch/torch_importer.cpp

@@ -49,6 +49,8 @@
 
 namespace cv {
 namespace dnn {
+CV__DNN_EXPERIMENTAL_NS_BEGIN
+
 #if defined(ENABLE_TORCH_IMPORTER) && ENABLE_TORCH_IMPORTER
 #include "THDiskFile.h"
 
@@ -1021,5 +1023,5 @@ Net readNetFromTorch(const String &model, bool isBinary)
     return net;
 }
 
-}
-}
+CV__DNN_EXPERIMENTAL_NS_END
+}} // namespace