/** * Load the block at the given offset. */ public override ByteBuffer GetBlockAt(int offset) { // Which big block is this? int byteOffset = offset * POIFSConstants.SMALL_BLOCK_SIZE; int bigBlockNumber = byteOffset / _filesystem.GetBigBlockSize(); int bigBlockOffset = byteOffset % _filesystem.GetBigBlockSize(); // Now locate the data block for it NPOIFSStream.StreamBlockByteBufferIterator it = _mini_stream.GetBlockIterator() as NPOIFSStream.StreamBlockByteBufferIterator; for (int i = 0; i < bigBlockNumber; i++) { it.Next(); } ByteBuffer dataBlock = it.Next(); if (dataBlock == null) { throw new IndexOutOfRangeException("Big block " + bigBlockNumber + " outside stream"); } // Position ourselves, and take a slice dataBlock.Position = dataBlock.Position + bigBlockOffset; ByteBuffer miniBuffer = dataBlock.Slice(); miniBuffer.Limit = POIFSConstants.SMALL_BLOCK_SIZE; return(miniBuffer); }
protected static void assertBATCount(NPOIFSFileSystem fs, int expectedBAT, int expectedXBAT) { int foundBAT = 0; int foundXBAT = 0; int sz = (int)(fs.Size / fs.GetBigBlockSize()); for (int i = 0; i < sz; i++) { if (fs.GetNextBlock(i) == POIFSConstants.FAT_SECTOR_BLOCK) { foundBAT++; } if (fs.GetNextBlock(i) == POIFSConstants.DIFAT_SECTOR_BLOCK) { foundXBAT++; } } Assert.AreEqual(expectedBAT, foundBAT, "Wrong number of BATs"); Assert.AreEqual(expectedXBAT, foundXBAT, "Wrong number of XBATs with " + expectedBAT + " BATs"); }