/// <summary>
/// Read data from an array of DocumentBlocks
/// </summary>
/// <param name="blocks">the blocks to Read from</param>
/// <param name="buffer">the buffer to Write the data into</param>
/// <param name="offset">the offset into the array of blocks to Read from</param>
public static void Read(DocumentBlock[] blocks,
byte[] buffer, int offset)
{
int firstBlockIndex = offset / POIFSConstants.BIG_BLOCK_SIZE;
int firstBlockOffSet = offset % POIFSConstants.BIG_BLOCK_SIZE;
int lastBlockIndex = (offset + buffer.Length - 1)
/ POIFSConstants.BIG_BLOCK_SIZE;
if (firstBlockIndex == lastBlockIndex)
{
Array.Copy(blocks[firstBlockIndex]._data,
firstBlockOffSet, buffer, 0, buffer.Length);
}
else
{
int buffer_offset = 0;
Array.Copy(blocks[firstBlockIndex]._data,
firstBlockOffSet, buffer, buffer_offset,
POIFSConstants.BIG_BLOCK_SIZE
- firstBlockOffSet);
buffer_offset += POIFSConstants.BIG_BLOCK_SIZE - firstBlockOffSet;
for (int j = firstBlockIndex + 1; j < lastBlockIndex; j++)
{
Array.Copy(blocks[j]._data, 0, buffer, buffer_offset,
POIFSConstants.BIG_BLOCK_SIZE);
buffer_offset += POIFSConstants.BIG_BLOCK_SIZE;
}
Array.Copy(blocks[lastBlockIndex]._data, 0, buffer,
buffer_offset, buffer.Length - buffer_offset);
}
}
public static DataInputBlock GetDataInputBlock(DocumentBlock[] blocks, int offset)
{
if (blocks == null || blocks.Length == 0)
return null;
POIFSBigBlockSize bigBlockSize = blocks[0].bigBlockSize;
int BLOCK_SHIFT = bigBlockSize.GetHeaderValue();
int BLOCK_SIZE = bigBlockSize.GetBigBlockSize();
int BLOCK_MASK = BLOCK_SIZE - 1;
int firstBlockIndex = offset >> BLOCK_SHIFT;
int firstBlockOffset = offset & BLOCK_MASK;
return new DataInputBlock(blocks[firstBlockIndex]._data, firstBlockOffset);
}
/// <summary>
/// convert a single long array into an array of DocumentBlock
/// instances
/// </summary>
/// <param name="array">the byte array to be converted</param>
/// <param name="size">the intended size of the array (which may be smaller)</param>
/// <returns>an array of DocumentBlock instances, filled from the
/// input array</returns>
public static DocumentBlock[] Convert(POIFSBigBlockSize bigBlockSize,
byte[] array,
int size)
{
DocumentBlock[] rval =
new DocumentBlock[(size + POIFSConstants.BIG_BLOCK_SIZE - 1) / POIFSConstants.BIG_BLOCK_SIZE];
int offset = 0;
for (int k = 0; k < rval.Length; k++)
{
rval[k] = new DocumentBlock(bigBlockSize);
if (offset < array.Length)
{
int length = Math.Min(POIFSConstants.BIG_BLOCK_SIZE,
array.Length - offset);
Array.Copy(array, offset, rval[k]._data, 0, length);
if (length != POIFSConstants.BIG_BLOCK_SIZE)
{
for (int j = (length > 0) ? (length - 1) : length; j < POIFSConstants.BIG_BLOCK_SIZE; j++)
{
rval[k]._data[j] = _default_value;
}
}
}
else
{
for (int j = 0; j < rval[k]._data.Length; j++)
{
rval[k]._data[j] = _default_value;
}
}
offset += POIFSConstants.BIG_BLOCK_SIZE;
}
return rval;
}