Binary String Types

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XSD defines the following types that are mapped to a C binary type structure:

hexBinary

base64Binary

The type of structure used depends on whether or not a length facet is applied to the type. If a length facet is not used, or the length is a very large value (> 32K), a built-in type containing a pointer to a dynamic memory buffer is used to hold the binary data. The definition of this type in rtxSysTypes.h is as follows:

typedef struct OSDynOctStr {
 
   OSUINT32     numocts;
 
   const OSOCTET* data;
 
} OSDynOctStr;
 

The numocts member holds the length of the binary string and the data member holds the actual data.

For C++, a built-in class definition is used that extends this structure:

	class OSDynOctStrClass : public OSDynOctStr, public OSBaseType {
 
	 public:
 
	   ...
 
	} ;
 

This class allows the base members to be accessed just as they were in the C case, but provides initialization through constructors and other utility methods as well.

If a length facet is used that restricts the size of the binary string to a value less than 32K, a custom type is generated that contains a static array to hold the data. The general form of this type is as follows:

      typedef struct TypeName {
 
         OSUINT32     numocts;
 
         OSOCTET      data[length];
 
      } TypeName;
 

In this case, TypeName would be the name of the type defined in the XSD specification and length would be the value of the length facet.

In the case of C++, a class is generated:

      class TypeName : public OSBaseType {
 
         OSUINT32     numocts;
 
         OSOCTET      data[length];
 
	   ...
 
      } ;
 

The general mappings for each case are as follows: