/**
* 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");
}