/** * 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; // Buffer the contents into memory. This is a bit icky... // TODO Replace with a buffer up to the mini stream size, then streaming write byte[] contents; if (stream is MemoryStream) { MemoryStream bais = (MemoryStream)stream; contents = new byte[bais.Length]; bais.Read(contents, 0, contents.Length); } else { MemoryStream baos = new MemoryStream(); IOUtils.Copy(stream, baos); contents = baos.ToArray(); } // Do we need to store as a mini stream or a full one? if (contents.Length <= POIFSConstants.BIG_BLOCK_MINIMUM_DOCUMENT_SIZE) { _stream = new NPOIFSStream(filesystem.GetMiniStore()); _block_size = _filesystem.GetMiniStore().GetBlockStoreBlockSize(); } else { _stream = new NPOIFSStream(filesystem); _block_size = _filesystem.GetBlockStoreBlockSize(); } // Store it _stream.UpdateContents(contents); // And build the property for it this._property = new DocumentProperty(name, contents.Length); _property.StartBlock = _stream.GetStartBlock(); }
/** * Load the block, extending the underlying stream if needed */ public override ByteBuffer CreateBlockIfNeeded(int offset) { // Try to Get it without extending the stream 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); // 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 it return(CreateBlockIfNeeded(offset)); } }