public void ProcessStream(Stream stream, BlockingCollectionDataChunk<int> positions,
BlockingCollectionDataChunk<uint> partitionHashValues, BlockingCollectionDataChunk<FileChunkInfo> fileChunkInfo)
{
var prevPos = 0;
var neededBytes = 0;
foreach (var posChunk in positions.BlockingCollection.GetConsumingEnumerable())
{
for (var i = 0; i < posChunk.DataSize; ++i )
{
var pos = posChunk.Data[i];
neededBytes = pos - prevPos + 1;
var hv = CalcStreamPortion(stream, neededBytes);
partitionHashValues.Add(hv);
fileChunkInfo.Add(new FileChunkInfo() { Pos = prevPos, Length = neededBytes });
// Prepare for next block.
prevPos = pos + 1;
}
}
// Handle the last partition
neededBytes = (int)stream.Length - prevPos;
if (neededBytes != 0)
{
var lastHv = CalcStreamPortion(stream, neededBytes);
partitionHashValues.Add(lastHv);
fileChunkInfo.Add(new FileChunkInfo() { Pos = prevPos, Length = neededBytes });
}
partitionHashValues.CompleteAdding();
fileChunkInfo.CompleteAdding();
}
public void StreamToHashValues(Stream inputStream, BlockingCollectionDataChunk<uint> hashValues)
{
// Read the source file into a byte array.
var prevBuffer = new byte[BufferSize];
var buffer = new byte[BufferSize];
var starting = true;
var prevHashValue = 0U;
var byteRead = 0;
var currHashEndIdx = -1;
var hEndIdx = -1;
while ((byteRead = inputStream.Read(buffer, 0, BufferSize)) != 0)
{
if (starting)
{
var hv = Adler32Checksum.Calculate(buffer, 0, HashBlock);
hashValues.Add(hv);
prevHashValue = hv;
starting = false;
currHashEndIdx = HashBlock - 1;
}
if (byteRead < BufferSize)
{
Array.Clear(buffer, byteRead, BufferSize - byteRead);
}
hEndIdx = byteRead + HashBlock - 2;
while (currHashEndIdx < BufferSize - 1 && currHashEndIdx != hEndIdx)
{
CalcAdlerHashEndIdx(ref currHashEndIdx, prevBuffer, buffer, ref prevHashValue, hashValues);
}
currHashEndIdx -= BufferSize;
hEndIdx -= BufferSize;
// Swap 2 buffers
var temp = buffer;
buffer = prevBuffer;
prevBuffer = temp;
}
if (currHashEndIdx != hEndIdx)
{
// Need an empty final block.
Array.Clear(buffer, 0, BufferSize);
while (currHashEndIdx != hEndIdx)
{
CalcAdlerHashEndIdx(ref currHashEndIdx, prevBuffer, buffer, ref prevHashValue, hashValues);
}
}
hashValues.CompleteAdding();
}
public void CalcNew(BlockingCollectionDataChunk<uint> inputList, BlockingCollectionDataChunk<int> outputPos)
{
var currBlockPos = 0;
foreach (var item in inputList.BlockingCollection.GetConsumingEnumerable())
{
for (var i = 0; i < item.DataSize; ++i)
{
var currHash = item.Data[i];
if (currHash % (2 * 512) == 0)
{
outputPos.Add(currBlockPos + i);
}
}
currBlockPos += item.DataSize;
}
outputPos.CompleteAdding();
}
static void ProcessFileNaive(string filename, List<int> partitionHash)
{
var rollingHash = new List<uint>();
var localMaximaPos = new List<int>();
var fciBC = new BlockingCollectionDataChunk<FileChunkInfo>();
var fileBytes = File.ReadAllBytes(filename);
using (var ms = new MemoryStream(fileBytes, 0, fileBytes.Length, true, true))
{
var fh = new FileHash(1024);
fh.StreamToHashValuesNaive(ms, rollingHash);
}
var lm = new LocalMaxima(4 * 1024);
lm.CalcUsingNaive(rollingHash, localMaximaPos);
var localMaximaPosBC = new BlockingCollectionDataChunk<int>();
foreach (var pos in localMaximaPos)
{
localMaximaPosBC.Add(pos);
}
localMaximaPosBC.CompleteAdding();
var ph = new BlockingCollectionDataChunk<uint>();
var mmh = new MurmurHash3_x86_32();
var fph = new FileParitionHash(mmh);
using (var fs = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read))
{
fph.ProcessStream(fs, localMaximaPosBC, ph, fciBC);
}
foreach (var items in ph.BlockingCollection.GetConsumingEnumerable())
{
for (var i = 0; i < items.DataSize; ++i)
{
partitionHash.Add((int)items.Data[i]);
}
}
}
public void CalcUsingBlockAlgo(BlockingCollectionDataChunk<uint> inputList, BlockingCollectionDataChunk<int> outputPos)
{
var currPos = 0;
var liveCanPrevBlockIdx = -1;
var liveCanPrevBlockVal = 0U;
var currBlockGreedySeq = new List<KeyValuePair<int, uint>>();
var prevBlockGreedySeq = new List<KeyValuePair<int, uint>>();
var currBlock = new uint[BlockSize];
var prevBlock = new uint[BlockSize];
var currWritingIdx = 0;
foreach (var item in inputList.BlockingCollection.GetConsumingEnumerable())
{
var nItemLeft = item.DataSize;
while (nItemLeft != 0)
{
// Constructing current block.
var copyLength = Math.Min(nItemLeft, BlockSize - currWritingIdx);
Array.Copy(item.Data, item.DataSize - nItemLeft, currBlock, currWritingIdx, copyLength);
nItemLeft -= copyLength;
currWritingIdx += copyLength;
if (currWritingIdx == BlockSize)
{
var currLiveCanIdx = ProcessOneBlock(currBlock, currPos, currBlockGreedySeq,
prevBlock, liveCanPrevBlockIdx, liveCanPrevBlockVal, prevBlockGreedySeq,
outputPos);
// Move on to the next block.
prevBlockGreedySeq = currBlockGreedySeq;
currBlockGreedySeq = new List<KeyValuePair<int, uint>>();
liveCanPrevBlockIdx = currLiveCanIdx;
if (liveCanPrevBlockIdx != -1)
{
liveCanPrevBlockVal = currBlock[liveCanPrevBlockIdx];
}
var temp = currBlock;
currBlock = prevBlock;
prevBlock = temp;
currWritingIdx = 0;
currPos += BlockSize;
}
}
}
if (currWritingIdx != 0)
{
// Handle non-full last block.
// Zero the remaining array.
Array.Clear(currBlock, currWritingIdx, currBlock.Length - currWritingIdx);
var currLiveCanIdx = ProcessOneBlock(currBlock, currPos, currBlockGreedySeq,
prevBlock, liveCanPrevBlockIdx, liveCanPrevBlockVal, prevBlockGreedySeq,
outputPos);
liveCanPrevBlockIdx = currLiveCanIdx;
if (liveCanPrevBlockIdx != -1)
{
liveCanPrevBlockVal = currBlock[liveCanPrevBlockIdx];
}
currPos += BlockSize;
}
if (liveCanPrevBlockIdx != -1)
{
outputPos.Add(currPos - prevBlock.Length + liveCanPrevBlockIdx);
}
outputPos.CompleteAdding();
}
private int ProcessOneBlock(IList<uint> currBlock, int currBlockStartPos, List<KeyValuePair<int, uint>> currGreedySeq,
IList<uint> prevBlock, int liveCanPrevBlockIdx, uint liveCanPrevBlockVal, List<KeyValuePair<int, uint>> prevGreddySeq,
BlockingCollectionDataChunk<int> localMaximaPos)
{
var currBlockStart = 0;
var currBlockEnd = currBlock.Count - 1;
currGreedySeq.Clear();
currGreedySeq.Add(new KeyValuePair<int, uint>(currBlockEnd, currBlock[currBlockEnd]));
var currLiveCanIdx = currBlockEnd;
if (liveCanPrevBlockIdx == -1)
{
// No live candidate in the previous block, do the ordinary run.
OrdinaryRun(currBlock, currBlockStart, currBlockEnd - 1, currGreedySeq, ref currLiveCanIdx);
}
else
{
// Live candidate in the prev block, do modified run on this block
// Ordinary until m + h (exclusive)
OrdinaryRun(currBlock, liveCanPrevBlockIdx, currBlockEnd - 1, currGreedySeq, ref currLiveCanIdx);
var lastInCurrGreedySeq = currGreedySeq[currGreedySeq.Count - 1].Value;
var modIdx = liveCanPrevBlockIdx - 1;
if (lastInCurrGreedySeq >= liveCanPrevBlockVal)
{
// F(g) >= F(m)
while (modIdx >= currBlockStart)
{
if (currBlock[modIdx] >= liveCanPrevBlockVal)
{
// Kill m
liveCanPrevBlockIdx = -1;
break;
}
--modIdx;
}
OrdinaryRun(currBlock, currBlockStart, modIdx, currGreedySeq, ref currLiveCanIdx);
}
else
{
// F(g) < F(m)
var lastValue = currGreedySeq[currGreedySeq.Count - 1].Value;
while (modIdx >= currBlockStart)
{
if (currBlock[modIdx] > lastValue)
{
// Strictly greater than, add to the greedy sequence.
currGreedySeq.Add(new KeyValuePair<int, uint>(modIdx, currBlock[modIdx]));
lastValue = currBlock[modIdx];
currLiveCanIdx = modIdx;
if (currBlock[modIdx] >= liveCanPrevBlockVal)
{
// Kill m
liveCanPrevBlockIdx = -1;
--modIdx;
break;
}
}
else if (currBlock[modIdx] == lastValue)
{
// Equal: kill the current candidate but don't add to the greedy sequence.
currLiveCanIdx = -1;
}
--modIdx;
}
OrdinaryRun(currBlock, currBlockStart, modIdx, currGreedySeq, ref currLiveCanIdx);
}
// After the modified run, if the candidate in the previous block is still alive => add to output.
if (liveCanPrevBlockIdx != -1)
{
localMaximaPos.Add(currBlockStartPos - prevBlock.Count + liveCanPrevBlockIdx);
}
}
// Check if current candidate satisfies all applicable items in the previous block.
if (currLiveCanIdx != -1)
{
for (var i = 0; i < prevGreddySeq.Count; ++i)
{
if (prevGreddySeq[i].Key < currLiveCanIdx + 1)
{
break;
}
if (prevGreddySeq[i].Value >= currBlock[currLiveCanIdx])
{
currLiveCanIdx = -1;
break;
}
}
}
return currLiveCanIdx;
}
List<KeyValuePair<int, int>> CalcUsingBlockAlgo(List<int> list)
{
var retPos = new BlockingCollectionDataChunk<int>();
var inList = new BlockingCollectionDataChunk<uint>();
foreach (var i in list)
{
inList.Add((uint)i);
}
inList.CompleteAdding();
CalcUsingBlockAlgo(inList, retPos);
return retPos.ToList().Select(pos => new KeyValuePair<int, int>(pos, list[pos])).ToList();
}
private void CalcHashEndIdxUInt32(ref int currHashEndIdx, byte[] buffer, ref uint prevHashValue, BlockingCollectionDataChunk<uint> hashValues)
{
currHashEndIdx += 1;
var inByte = buffer[currHashEndIdx];
var bitMask = (uint)(inByte << 24);
var hv = (prevHashValue >> 8) | bitMask;
hashValues.Add(hv);
prevHashValue = hv;
}
private void CalcAdlerHashEndIdx(ref int currHashEndIdx, byte[] prevBuffer, byte[] buffer, ref uint prevHashValue, BlockingCollectionDataChunk<uint> hashValues)
{
currHashEndIdx += 1;
var hashStartIdx = currHashEndIdx - HashBlock;
var outByte = hashStartIdx < 0 ? prevBuffer[BufferSize + hashStartIdx] : buffer[hashStartIdx];
var hv = Adler32Checksum.Roll(outByte, buffer[currHashEndIdx], prevHashValue, HashBlock);
hashValues.Add(hv);
prevHashValue = hv;
}
public void StreamToUInt32HashValues(Stream inputStream, BlockingCollectionDataChunk<uint> hashValues)
{
// Read the source file into a byte array.
var buffer = new byte[BufferSize];
var starting = true;
var prevHashValue = 0U;
var byteRead = 0;
var currHashEndIdx = -1;
var hEndIdx = -1;
while ((byteRead = inputStream.Read(buffer, 0, BufferSize)) != 0)
{
if (starting)
{
var hv = BitConverter.ToUInt32(buffer, 0);
hashValues.Add(hv);
prevHashValue = hv;
starting = false;
currHashEndIdx = 4 - 1;
}
if (byteRead < BufferSize)
{
Array.Clear(buffer, byteRead, BufferSize - byteRead);
}
hEndIdx = byteRead + 4 - 2;
while (currHashEndIdx < BufferSize - 1 && currHashEndIdx != hEndIdx)
{
CalcHashEndIdxUInt32(ref currHashEndIdx, buffer, ref prevHashValue, hashValues);
}
currHashEndIdx -= BufferSize;
hEndIdx -= BufferSize;
}
if (currHashEndIdx != hEndIdx)
{
// Need an empty final block.
Array.Clear(buffer, 0, BufferSize);
while (currHashEndIdx != hEndIdx)
{
CalcHashEndIdxUInt32(ref currHashEndIdx, buffer, ref prevHashValue, hashValues);
}
}
hashValues.CompleteAdding();
}