ENH: Add GetNumberOf function to MetadataSupplierInterface

Data/Baseline/OTB/Files/ioTuotbXMLMetadataSupplierTest.txt

 OrthoRectification
 Output Cartographic Map Projection
-
+12

Modules/Core/Metadata/include/otbGeomMetadataSupplier.h

@@ -69,6 +69,12 @@ public:
    */
   bool FetchRPC(ImageMetadata & imd);
 
+  /** Get the number of keys starting with path */
+  unsigned int GetNumberOf(std::string const&) const override
+  {
+    otbLogMacro(Error, << "GetNumberOf() not yet implemented in otbGeomMetadataSupplier");
+  }
+
   /**
    * @brief Writes the content of the Geom file into a string
    *

Modules/Core/Metadata/include/otbMetadataSupplierInterface.h

@@ -75,6 +75,9 @@ public:
    *  If size>=0, then the final std::vector size is checked and an exception
    *  is raised if it doesn't match the given size.*/
   template < typename T> std::vector<T> GetAsVector(std::string const& path, char sep=' ', int size=-1, int band=-1) const;
+
+  /** Get the number of keys starting with path */
+  virtual unsigned int GetNumberOf(std::string const& path) const = 0;
 };
 
 // TODO : for complex types ...

Modules/Core/Metadata/include/otbXMLMetadataSupplier.h

@@ -102,6 +102,9 @@ public:
 
   int GetNbBands() const override;
 
+  /** Get the number of keys starting with path */
+  unsigned int GetNumberOf(std::string const& path) const override;
+
   /**
    * @brief Writes the content of the XML file into a string
    *
@@ -145,7 +148,16 @@ protected:
    *         contain Name
    */
   std::vector<std::string> FetchPartialNameValueMultiple(const std::vector<std::string> &StringVector,
-		                                                 const std::string &Name) const;
+                                                     const std::string &Name) const;
+
+  /**
+   * @brief In a StringList of “Name=Value” pairs, look for the keys equal to the specified string
+   * @param papszStrList A StringList that will be searched
+   * @param pszName A string that will be looked for at the begining of the keys
+   * @return A StringList containing only the pairs from papszStrList whose key
+   *         start with pszName
+   */
+  std::vector<std::string> GetAllStartWith(char** papszStrList, const char *pszName) const;
 
 private:
   /** List of resource files */

Modules/Core/Metadata/src/otbGeomMetadataSupplier.cxx

@@ -36,7 +36,7 @@ GeomMetadataSupplier::GeomMetadataSupplier(std::string const& fileName)
   this->ReadGeomFile();
 }
 
-std::string GeomMetadataSupplier::GetMetadataValue(std::string const& path, bool& hasValue, int band) const
+std::string GeomMetadataSupplier::GetMetadataValue(std::string const& path, bool& hasValue, int) const
 {
   auto value = this->m_MetadataDic.find(path);
   if(value != this->m_MetadataDic.end())
@@ -48,7 +48,7 @@ std::string GeomMetadataSupplier::GetMetadataValue(std::string const& path, bool
   return "";
 }
 
-std::string GeomMetadataSupplier::GetResourceFile(std::string const& s) const
+std::string GeomMetadataSupplier::GetResourceFile(std::string const&) const
 {
   return this->m_FileName;
 }

Modules/Core/Metadata/src/otbXMLMetadataSupplier.cxx

@@ -19,6 +19,7 @@
  */
 
 #include "otbXMLMetadataSupplier.h"
+#include <unordered_set>
 
 namespace otb
 {
@@ -220,11 +221,39 @@ std::vector<std::string> XMLMetadataSupplier::FetchPartialNameValueMultiple(cons
   return retStringVector;
 }
 
+std::vector<std::string> XMLMetadataSupplier::GetAllStartWith(char** papszStrList,
+                                                                  const char *pszName) const
+{
+  std::vector<std::string> retStringVector;
+  if( papszStrList == nullptr || pszName == nullptr )
+    return retStringVector;
+
+  for( ; *papszStrList != nullptr ; ++papszStrList )
+    if( strstr(*papszStrList, pszName) == *papszStrList)
+      retStringVector.push_back(*papszStrList);
+  return retStringVector;
+}
+
 int XMLMetadataSupplier::GetNbBands() const
 {
   return 0;
 }
 
+unsigned int XMLMetadataSupplier::GetNumberOf(std::string const & path) const
+{
+  std::unordered_set<int> idx;
+  for(auto const& key : GetAllStartWith(m_MetadataDic, path.c_str()))
+  {
+    auto after = key.substr(path.size());
+    if(after.size() > 0 && after.compare(0, 1, "_") == 0)
+    {
+      auto sub = after.substr(1, after.find("."));
+      idx.insert(std::stoi(sub));
+    }
+  }
+  return idx.size();
+}
+
 std::string XMLMetadataSupplier::PrintSelf()
 {
   std::ostringstream oss;

Modules/Core/Metadata/test/otbXMLMetadataSupplierTest.cxx

@@ -32,6 +32,7 @@ int otbXMLMetadataSupplierTest(int itkNotUsed(argc), char* argv[])
   file.open(outputFilename);
   file << mds.GetMetadataValue("OTB.application.name", hasValue) << "\n";
   file << mds.GetMetadataValue("OTB.application.parameter_3.name", hasValue) << "\n";
+  file << mds.GetNumberOf("OTB.application.parameter") << "\n";
   file.close();
 
   return EXIT_SUCCESS;

Modules/IO/IOGDAL/include/otbGDALImageIO.h

@@ -219,6 +219,13 @@ public:
   /** Set the projection system from EPSG code */
   void SetEpsgCode(const unsigned int wellKnownCRS);
 
+  /** Get the number of keys starting with path */
+  unsigned int GetNumberOf(std::string const&) const override
+  {
+    itkExceptionMacro(
+        "GetNumberOf() not yet implemented in otbGDALImageIO");
+  }
+
 protected:
   /**
    * Constructor.