private static byte[][] ReadLeafs(HashAlgorithm tg, string filePath, long start, long end)
{
using (ThreadUtility.EnterBackgroundProcessingMode())
using (var threadFilePtr = FileStreamFactory.CreateFileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read, 128 * 1024))
{
var threadFileBlock = new FileBlock(start, end);
var LeafSize = 1024;
var DataBlockSize = LeafSize * 1024;
var data = new byte[LeafSize + 1];
var totalLeafs = threadFileBlock.Length / LeafSize + threadFileBlock.Length % LeafSize > 0 ? 1 : 0;
var result = new byte[totalLeafs][];
threadFilePtr.Position = threadFileBlock.Start;
while (threadFilePtr.Position < threadFileBlock.End)
{
var leafIndex = (int)((threadFilePtr.Position - start) / 1024);
var dataBlock = new byte[Math.Min(threadFileBlock.End - threadFilePtr.Position, DataBlockSize)];
threadFilePtr.Read(dataBlock, 0, dataBlock.Length); //read block
var blockLeafs = dataBlock.Length / LeafSize;
int i;
for (i = 0; i < blockLeafs; i++)
{
Buffer.BlockCopy(dataBlock, i * LeafSize, data, 1, LeafSize);
tg.Initialize();
result[leafIndex++] = tg.ComputeHash(data);
}
if (i * LeafSize < dataBlock.Length)
{
data = new byte[dataBlock.Length - blockLeafs * LeafSize + 1];
data[0] = LeafHash;
Buffer.BlockCopy(dataBlock, blockLeafs * LeafSize, data, 1, (data.Length - 1));
tg.Initialize();
result[leafIndex] = tg.ComputeHash(data);
data = new byte[LeafSize + 1];
data[0] = LeafHash;
}
}
return(result);
}
}
void SplitFile()
{
long leafsInPart = _leafCount / ThreadCount;
// check if file is bigger than 1 MB or don't use threads
if (_filePtr.Length > 1024 * 1024)
{
for (int i = 0; i < ThreadCount; i++)
{
_fileParts[i] = new FileBlock(leafsInPart * LeafSize * i,
leafsInPart * LeafSize * (i + 1));
}
}
_fileParts[ThreadCount - 1].End = _filePtr.Length;
}