Purpose: Improvement for HDFFV-10004

Description:
    When adding wrappers for H5Lexists, a new class, LinkAccPropList, was
    added to the C++ API, triggered complicated circular dependencies.  Thus,
    some improvement was made to resolve the problems.
    - Replaced existing functions openXxxType with individual type constructors
      + Added individual XxxType constructors to replace the existing functions
        openXxxType because it's rather awkward to use these functions.
      + Moved openXxxType from H5Location back to CommonFG
      + Put back CommonFG as a baseclass of Group for openXxxType functions.
      + This replacement should improve usability and prevent the problem of
        circular dependencies.
    - Removed overloaded constructor that takes an Attribute when there is
        already one that takes H5Location because Attribute inherits from
        H5Location now.
Platforms tested:
    Linux/32 2.6 (jam)
    Darwin (osx1010test)
    Linux/64 (platypus)

1 files changed, 61 insertions, 5 deletions

diff --git a/c++/src/H5DataType.cpp b/c++/src/H5DataType.cpp
index 7dcd343..3955ebf 100644
--- a/c++/src/H5DataType.cpp
+++ b/c++/src/H5DataType.cpp
@@ -23,13 +23,13 @@
 #include "H5Include.h"
 #include "H5Exception.h"
 #include "H5IdComponent.h"
+#include "H5DataSpace.h"
 #include "H5PropList.h"
 #include "H5FaccProp.h"
 #include "H5FcreatProp.h"
 #include "H5OcreatProp.h"
 #include "H5DcreatProp.h"
 #include "H5DxferProp.h"
-#include "H5DataSpace.h"
 #include "H5Location.h"
 #include "H5Object.h"
 #include "H5DataType.h"
@@ -38,8 +38,6 @@
 #include "H5private.h"
 #include "H5AbstractDs.h"
 #include "H5DataSet.h"
-#include "H5Group.h"
-#include "H5File.h"
 #include "H5Attribute.h"
 
 namespace H5 {
@@ -122,10 +120,11 @@ DataType::DataType(const H5Location& loc, const void* ref, H5R_type_t ref_type,
 //	Jul, 2008
 //		Added for application convenience.
 //--------------------------------------------------------------------------
-DataType::DataType(const Attribute& attr, const void* ref, H5R_type_t ref_type, const PropList& plist) : H5Object(), id(H5I_INVALID_HID)
+ /* DataType::DataType(const Attribute& attr, const void* ref, H5R_type_t ref_type, const PropList& plist) : H5Object(), id(H5I_INVALID_HID)
 {
     id = H5Location::p_dereference(attr.getId(), ref, ref_type, plist, "constructor - by dereference");
 }
+ */ 
 
 //--------------------------------------------------------------------------
 // Function:	DataType copy constructor
@@ -152,13 +151,49 @@ DataType::DataType(const DataType& original) : H5Object(), id(original.id)
 //--------------------------------------------------------------------------
 DataType::DataType(const PredType& pred_type) : H5Object()
 {
-    // call C routine to copy the datatype
+    // Call C routine to copy the datatype
     id = H5Tcopy( pred_type.getId() );
     if (id < 0)
 	throw DataTypeIException("DataType constructor", "H5Tcopy failed");
 }
 
 //--------------------------------------------------------------------------
+// Function:    DataType overloaded constructor
+///\brief       Creates a DataType instance by opening an HDF5 datatype given
+///		its name as a char*.
+///\param       dtype_name - IN: Datatype name
+///\exception   H5::DataTypeIException
+// Programmer   Binh-Minh Ribler - Dec 2016
+// Description
+//		In 1.10.1, this constructor was introduced and will replace the
+//		existing function CommonFG::openDataType(const char*) to
+//		improve usability.
+//		-BMR, Dec 2016
+//--------------------------------------------------------------------------
+DataType::DataType(const H5Location& loc, const char *dtype_name) : H5Object()
+{
+    id = p_opentype(loc, dtype_name);
+}
+
+//--------------------------------------------------------------------------
+// Function:    DataType overloaded constructor
+///\brief	Creates a DataType instance by opening an HDF5 datatype given
+///		its name as an \c H5std_string.
+///\param       dtype_name - IN: Datatype name
+///\exception   H5::DataTypeIException
+// Programmer   Binh-Minh Ribler - Dec 2016
+// Description
+//		In 1.10.1, this constructor was introduced and will replace the
+//		existing function CommonFG::openDataType(const H5std_string&) to
+//		improve usability.
+//		-BMR, Dec 2016
+//--------------------------------------------------------------------------
+DataType::DataType(const H5Location& loc, const H5std_string& dtype_name) : H5Object()
+{
+    id = p_opentype(loc, dtype_name.c_str());
+}
+
+//--------------------------------------------------------------------------
 // Function:	DataType::copy
 ///\brief	Copies an existing datatype to this datatype object
 ///\param	like_type - IN: Datatype to be copied
@@ -264,6 +299,27 @@ bool DataType::operator==(const DataType& compared_type ) const
 }
 
 //--------------------------------------------------------------------------
+// Function:    DataType::p_opentype (private)
+///\brief       Opens an HDF5 datatype given its name
+///\param       dtype_name - IN: Datatype name
+///\exception   H5::DataTypeIException
+// Programmer   Binh-Minh Ribler - Dec 2016
+// Description
+//		This function was introduced in 1.10.1 to be used by the new
+//		XxxType constructors that were introduced to replace the
+//		existing functions CommonFG::openXxxType(), which is awkward
+//		to use.  -BMR, Dec 2016
+//--------------------------------------------------------------------------
+hid_t DataType::p_opentype(const H5Location& loc, const char *dtype_name) const
+{
+    // Call C function to open the named datatype at this location
+    hid_t ret_value = H5Topen2(loc.getId(), dtype_name, H5P_DEFAULT);
+    if (ret_value < 0)
+	throw DataTypeIException("DataType constructor", "H5Topen2 failed");
+    return(ret_value);
+}
+
+//--------------------------------------------------------------------------
 // Function:	DataType::p_commit (private)
 //\brief	Commits a transient datatype to a file, creating a new
 //		named datatype