/**
* Repositions this stream to the position at the time the mark() method was
* last called on this input stream. If mark() has not been called this
* method repositions the stream to its beginning.
*/
public override void Reset()
{
// Special case for Reset to the start
if (_marked_offset == 0 && _marked_offset_count == 0)
{
_current_block_count = _marked_offset_count;
_current_offset = _marked_offset;
_data = _document.GetBlockIterator();
_buffer = null;
return;
}
// Start again, then wind on to the required block
_data = _document.GetBlockIterator();
_current_offset = 0;
for (int i = 0; i < _marked_offset_count; i++)
{
_data.MoveNext();
_buffer = _data.Current;
_current_offset += _buffer.Remain;
}
_current_block_count = _marked_offset_count;
// Do we need to position within it?
if (_current_offset != _marked_offset)
{
// Grab the right block
_data.MoveNext();
_buffer = _data.Current;
_current_block_count++;
// Skip to the right place in it
// (It should be positioned already at the start of the block,
// we need to Move further inside the block)
int skipBy = _marked_offset - _current_offset;
_buffer.Position = (_buffer.Position + skipBy);
}
// All done
_current_offset = _marked_offset;
}
/**
* Create an InputStream from the specified Document
*
* @param document the Document to be read
*/
public NDocumentInputStream(NPOIFSDocument document)
{
_current_offset = 0;
_current_block_count = 0;
_marked_offset = 0;
_marked_offset_count = 0;
_document_size = document.Size;
_closed = false;
_document = document;
_data = _document.GetBlockIterator();
}
/**
* Create an InputStream from the specified DocumentEntry
*
* @param document the DocumentEntry to be read
*
* @exception IOException if the DocumentEntry cannot be opened (like, maybe it has
* been deleted?)
*/
public NDocumentInputStream(DocumentEntry document)
{
if (!(document is DocumentNode))
{
throw new IOException("Cannot open internal document storage, " + document + " not a Document Node");
}
_current_offset = 0;
_current_block_count = 0;
_marked_offset = 0;
_marked_offset_count = 0;
_document_size = document.Size;
_closed = false;
DocumentNode doc = (DocumentNode)document;
DocumentProperty property = (DocumentProperty)doc.Property;
_document = new NPOIFSDocument(
property,
((DirectoryNode)doc.Parent).NFileSystem
);
_data = _document.GetBlockIterator();
}