[xsd-users] Calculating progress on "xsd-parser" parsed files

[Boris Kolpackov]

Hi David,

David White <dawhite32 at gmail.com> writes:

> Is it possible to get an indication of conversion process with 
> xsd / xerces?

There is no built-in support for this though it is relatively
easy to do. There are also several ways you can do it. You can
use the underlying SAX2 parser's (SAX2XMLReader) getSrcOffset()
function along with the total file length to determine the
progress. Or you can use the file stream position to get the
same information. In either case the overall structure of the
code will be the same. You probably have a top-level parser
with one of its callbacks being called periodically as parsing
progresses. Something along these lines:

<complexType name="root">
  <sequence>
    <element name="record" maxOccurs="unbounded">

      ...

    </element>
  </sequence>
</complexType>

<element name="root" type="root"/>

You can pass the file stream or SAX2 parser reference to the
parser for this top-level type and then calculate the progress
each time the callback is called, something along these lines:

struct root_pimpl: root_pskel
{
  root_pimpl (std::ifstream& is, size_t size)
    : is_ (is), size_ (size)
  {
  }
  
  virtual void 
  record (...)
  {
    // Callculate the progress.
    //
    size_t cur = is_.tellg ();
    ...
  }

private:
  std::ifstream& is_;
  size size_;
};

int 
main ()
{
  ifstream ifs;
  ifs.exceptions (ios_base::failbit);
  ifs.open (file, ios::in | ios::ate);
  size_t size (ifs.tellg ());
  ifs.seekg (0, ios::beg);

  root_pimpl root_p (ifs, size);
 
  ...

  xml_schema::document doc (root_p, "root");

  ...
}

Boris