/// <summary>
/// This reads input file and transfers bytes to Huffman code.
/// </summary>
/// <param name="nodes">Prepared hash table with codes for every type of byte.</param>
/// <param name="fileIn">Input stream.</param>
/// <param name="fileOut">Output stream.</param>
/// <exception cref="System.OutOfMemoryException">BEWARE OF OUT OF MEMORY EXCEPTION</exception>
internal static void EncodeFileBytes(BitArray[] nodes, BinaryReader fileIn, BinaryWriter fileOut)
{
int maxBufferSize = 100000; //Maximum for Huffman I => 1000000
int bufferPos = 0;
BitArray writeBuffer = new BitArray(maxBufferSize * 8);
while (fileIn.BaseStream.Position != fileIn.BaseStream.Length)
{
long diff = fileIn.BaseStream.Length - fileIn.BaseStream.Position;
int maxSize = diff < maxBufferSize ? (int)(diff) : maxBufferSize;
byte[] bytesBuffer = fileIn.ReadBytes(maxSize);
for (int i = 0; i < bytesBuffer.Length; i++)
{
BitArray keyStream = nodes[bytesBuffer[i]];
BitArray tmp = BitArrayExtender.TryAppend(writeBuffer, bufferPos, keyStream);
if (tmp != null)
{
fileOut.Write(BitArrayExtender.ToByteArray(writeBuffer));
BitArrayExtender.TryAppend(writeBuffer, 0, tmp);
bufferPos = tmp.Length;
}
else
{
bufferPos += keyStream.Length;
}
}
}
writeBuffer.Length = bufferPos;
fileOut.Write(BitArrayExtender.ToByteArray(writeBuffer));
}
/// <summary>
/// Creates 64bit representation of Huffman Tree Node as:
/// list: 0bit = 1
/// 1-55bit = node.sum
/// 56-64 = node.code
/// inner: 0bit = 0
/// 1-55bit = node.sum
/// 56-64 = 0
/// </summary>
/// <param name="tree">Current node.</param>
/// <param name="fileOut">Output stream.</param>
private void PrintNodeBinary(Node tree, BinaryWriter fileOut)
{
BitArray sumBits = new BitArray(BitConverter.GetBytes(tree.Sum));
BitArray node = new BitArray(64, false);
BitArrayExtender.CopyToFromBitArray(1, 0, 55, sumBits, node);
//List
if (tree.Order == 0)
{
BitArray codeByte = new BitArray(new[] { tree.Code });
node.Set(0, true);
BitArrayExtender.CopyToFromBitArray(56, 0, 8, codeByte, node);
}
//Inner
else
{
node.Set(0, false);
}
byte[] nodeBytes = BitArrayExtender.ToByteArray(node);
fileOut.Write(nodeBytes);
}
