/**
* Constructor for a new Document
*
* @param name the name of the POIFSDocument
* @param stream the InputStream we read data from
*/
public NPOIFSDocument(String name, NPOIFSFileSystem filesystem, Stream stream)
{
this._filesystem = filesystem;
// sotre it
int length = Store(stream);
// Build the property for it
this._property = new DocumentProperty(name, length);
_property.StartBlock = _stream.GetStartBlock();
}
/**
* Load the block, extending the underlying stream if needed
*/
public override ByteBuffer CreateBlockIfNeeded(int offset)
{
bool firstInStore = false;
// If we are the first block to be allocated, initialise the stream
if (_mini_stream.GetStartBlock() == POIFSConstants.END_OF_CHAIN)
{
firstInStore = true;
}
// Try to Get it without extending the stream
if (!firstInStore)
{
try
{
return(GetBlockAt(offset));
}catch (IndexOutOfRangeException) {}
}
// Need to extend the stream
// TODO Replace this with proper append support
// For now, do the extending by hand...
// Ask for another block
int newBigBlock = _filesystem.GetFreeBlock();
_filesystem.CreateBlockIfNeeded(newBigBlock);
// If we are the first block to be allocated, initialise the stream
if (firstInStore)
{
_filesystem.PropertyTable.Root.StartBlock = (newBigBlock);
_mini_stream = new NPOIFSStream(_filesystem, newBigBlock);
}
else
{
// Tack it onto the end of our chain
ChainLoopDetector loopDetector = _filesystem.GetChainLoopDetector();
int block = _mini_stream.GetStartBlock();
while (true)
{
loopDetector.Claim(block);
int next = _filesystem.GetNextBlock(block);
if (next == POIFSConstants.END_OF_CHAIN)
{
break;
}
block = next;
}
_filesystem.SetNextBlock(block, newBigBlock);
}
_filesystem.SetNextBlock(newBigBlock, POIFSConstants.END_OF_CHAIN);
// Now try again, to get the real small block
return(CreateBlockIfNeeded(offset));
}
public override void Close()
{
base.Close();
// Do we have a pending buffer for the mini stream?
if (_buffer != null)
{
// It's not much data, so ask NPOIFSDocument to do it for us
_document.ReplaceContents(new MemoryStream(_buffer.ToArray()));
}
else
{
// We've been writing to the stream as we've gone along
// Update the details on the property now
_stream_output.Close();
_property.UpdateSize(_document_size);
_property.StartBlock = (_stream.GetStartBlock());
}
// No more!
_closed = true;
}
