public void BitArrayFactory_Constructor_Validation()
{
try
{
_ = new BitArraySlim <ByteArray1>(-1);
Assert.Fail();
}
catch (ArgumentOutOfRangeException)
{
}
try
{
_ = new BitArraySlim <ByteArray1>(9);
Assert.Fail();
}
catch (ArgumentOutOfRangeException)
{
}
_ = new BitArraySlim <ByteArrayGinormous>(255);
try
{
// Small bit array restricts the max size of the underlying
// byte array so it can save space by only using a byte for
// the field it uses to store the size
_ = new BitArraySlim <ByteArrayGinormous>(256);
Assert.Fail();
}
catch (ArgumentOutOfRangeException)
{
}
}
private static PreSumsData FinishCreateSumsData(int number, BitArraySlim currSums, int currSumsCount, PartialSumsData data)
{
if (data.SumsCount != -1)
{
int uniqueSums = data.SumsCount - currSumsCount;
return(new PreSumsData(currSums, uniqueSums));
}
if (data.SumsCount == -1)
{
CreateAllSums(number, currSums, data);
data.SumsCount = BoolArrayTrueCount(data.Sums);
}
int uniques = 0;
for (int i = 0; i < currSums.Length; i++)
{
if (currSums[i] == 1)
{
int newSum = i + number;
if (newSum >= currSums.Length)
{
uniques++;
}
else if (currSums[newSum] == 0)
{
uniques++;
}
}
}
return(new PreSumsData(currSums, uniques));
}
internal void CopyToAndClearRest(BitArraySlim copyTo)
{
int copyLength = GetCurrentArrayLength();
int fillLength = copyTo.GetCurrentArrayLength() - copyLength;
Array.Copy(Bytes, copyTo.Bytes, copyLength);
Array.Fill(copyTo.Bytes, 0ul, copyLength, fillLength + GetSizeDiff <Vector256 <byte>, ulong>());
}
internal PartialSumsData(int maxSum)
{
FoundData = new HashSet <int>();
Datas = new BestSumsData();
Minuniques = int.MaxValue;
SumsCount = -1;
Created = 0;
Sums = null;
Storage = new BitArrayStorage(maxSum);
}
private static int BoolArrayTrueCount(BitArraySlim array)
{
int trueCount = 0;
int elementCount = array.GetCurrentArrayLength();
for (int i = 0; i < elementCount; i++)
{
trueCount += BitOperations.PopCount(array.Bytes[i]);
}
return(trueCount);
}
private static bool CreateAllSumsDatas(Span <int> numbers, BitArraySlim currSums, PartialSumsData data)
{
if (numbers.Length > 1)
{
int midPoint = numbers.Length / 2;
Span <int> firstPart = numbers.Slice(0, midPoint);
Span <int> secondPart = numbers.Slice(midPoint);
BitArraySlim secondPartSums = CreatePartialSums(secondPart, currSums, data);
if (!CreateAllSumsDatas(firstPart, secondPartSums, data))
{
data.Storage.Push(secondPartSums);
}
BitArraySlim firstPartSums = CreatePartialSums(firstPart, currSums, data);
if (!CreateAllSumsDatas(secondPart, firstPartSums, data))
{
data.Storage.Push(firstPartSums);
}
}
else
{
data.Created++;
int actualSumCount = BoolArrayTrueCount(currSums);
if (data.SumsCount - actualSumCount > data.Minuniques)
{
return(false);
}
int number = numbers[0];
if (!data.FoundData.Contains(number))
{
BestSumsData newData = new BestSumsData(number, FinishCreateSumsData(number, currSums, actualSumCount, data));
data.Minuniques = Math.Min(data.Minuniques, data.Datas.Data.Uniques);
if (newData.Data.Uniques < data.Datas.Data.Uniques ||
(newData.Data.Uniques == data.Datas.Data.Uniques &&
newData.Number < data.Datas.Number))
{
if (data.Datas.Data.BitArray != null)
{
data.Storage.Push(data.Datas.Data.BitArray);
}
data.Datas = newData;
return(true);
}
}
}
return(false);
}
// http://imysql.com/mysql-internal-manual/com-stmt-execute.html
public static void WriteExecuteStatement(ref PacketWriter writer, int statementId, object[] parameters) // Can I avoid boxing? array allocation?
{
/*
* 1 [17] COM_STMT_EXECUTE
* 4 stmt-id
* 1 flags
* 4 iteration-count
* if num-params > 0:
* n NULL-bitmap, length: (num-params+7)/8
* 1 new-params-bound-flag
* if new-params-bound-flag == 1:
* n type of each parameter, length: num-params * 2
* n value of each parameter
*/
writer.WriteByte((byte)CommandId.ExecuteStatement);
writer.WriteInt32(statementId);
writer.WriteByte((byte)ExecuteStatementFlags.ReadOnly); // flags
writer.WriteInt32(1); // The iteration-count is always 1
if (parameters.Length > 0)
{
var nullMap = new BitArraySlim(parameters.Length);
var nullMapLength = (parameters.Length + 7) / 8;
var nullBitMapOffset = writer.CurrentOffset; // save and after use
writer.Skip(nullMapLength);
for (int i = 0; i < parameters.Length; i++)
{
if (parameters[i] == null)
{
nullMap[i] = true;
continue;
}
nullMap[i] = false;
// TODO:write parameter type
MySqlParameterWriter.Write(ref writer, parameters[i]);
}
var offset = writer.CurrentOffset;
writer.Seek(nullBitMapOffset); // ready for null-map position
nullMap.WriteTo(ref writer);
writer.Seek(offset); // return to end
}
}
internal BitArraySlim Pop(int length)
{
if (Arrays.Count == 0)
{
return(new BitArraySlim(length, MaxSum + 1));
}
else
{
BitArraySlim arr = Arrays.Pop();
arr.Reuse(length);
return(arr);
}
}
public static (int number, int newNumber) Solve(int[] numbers)
{
Array.Sort(numbers);
int maxSum = 0;
for (int i = 0; i < numbers.Length; i++)
{
maxSum += numbers[i];
}
PartialSumsData data = new PartialSumsData(maxSum);
BitArraySlim currSums = new BitArraySlim(1);
currSums.ForceSet(0, 1);
CreateAllSumsDatas(numbers, currSums, data);
return(CreateCollisionAvoidanceArray(data.Sums, data.Datas, data));
}
private static (int number, int newNumber) CreateCollisionAvoidanceArray(BitArraySlim sums, BestSumsData bestData, PartialSumsData data)
{
SumsData sumData = bestData.Data.ToSumsData(bestData.Number, data.SumsCount);
foreach (var unique in sumData.Uniques)
{
sums.ForceSet(unique, 0);
}
for (int i = 1; i <= sums.Length;)
{
bool foundObstacle = false;
foreach (var newSum in sumData.NewSums)
{
int overlapIndex = newSum - (bestData.Number - i);
int offset = 0;
while (overlapIndex + offset < sums.Length && sums[overlapIndex + offset] == 1)
{
offset++;
}
i += offset;
if (offset > 0)
{
foundObstacle = true;
break;
}
}
if (!foundObstacle)
{
return(bestData.Number, i);
}
}
throw new Exception("impossible!.... i thought");
}
private static BitArraySlim CreatePartialSums(Span <int> numbers, BitArraySlim currSums, PartialSumsData data)
{
int maxSum = currSums.Length;
for (int i = 0; i < numbers.Length; i++)
{
maxSum += numbers[i];
}
BitArraySlim newSums = data.Storage.Pop(maxSum);
currSums.CopyToAndClearRest(newSums);
int prevMaxSum = currSums.Length - 1;
for (int i = 0; i < numbers.Length; i++)
{
CreateSumsVectorized(prevMaxSum, numbers[i], newSums);
prevMaxSum += numbers[i];
}
return(newSums);
}
internal PreSumsData(bool _)
{
BitArray = null;
Uniques = int.MaxValue;
}
internal PreSumsData(BitArraySlim bits, int uniqs)
{
BitArray = bits;
Uniques = uniqs;
}
private static unsafe void CreateSumsVectorized(int z, int number, BitArraySlim newSums)
{
BitArrayIndices numberOffset = new BitArrayIndices(number);
int length = ((z + number) / BitCount <ulong>());
fixed(ulong *arr = newSums.Bytes)
{
ulong *lastPtr = arr + length;
ulong *currPtr = lastPtr - numberOffset.ByteIndex;
int sizeFromUint;
if (Avx2.IsSupported)
{
sizeFromUint = GetSizeDiff <Vector256 <ulong>, ulong>();
}
else if (Sse2.IsSupported)
{
sizeFromUint = GetSizeDiff <Vector128 <ulong>, ulong>();
}
else
{
sizeFromUint = GetSizeDiff <ulong, ulong>();
}
int iterations = length - numberOffset.ByteIndex;
int rest = (sizeFromUint - (iterations % sizeFromUint)) % sizeFromUint;
iterations += rest;
lastPtr += rest;
currPtr += rest;
if (numberOffset.BitIndex % BitCount <byte>() == 0)
{
int offset = numberOffset.BitIndex / BitCount <byte>();
lastPtr = (ulong *)(((byte *)lastPtr) + offset);
for (int i = 0; i <= iterations; i += sizeFromUint)
{
if (Avx2.IsSupported)
{
moveSumsNoShift256bit(lastPtr - i, currPtr - i);
}
else if (Sse2.IsSupported)
{
moveSumsNoShift128bit(lastPtr - i, currPtr - i);
}
else
{
moveSumsNoShift64bit(lastPtr - i, currPtr - i);
}
}
}
else
{
for (int i = -1; i <= iterations - 1; i += sizeFromUint)
{
if (Avx2.IsSupported)
{
moveSumsWithShift256bit(lastPtr - i, currPtr - i, numberOffset.BitIndex);
}
else if (Sse2.IsSupported)
{
moveSumsWithShift128bit(lastPtr - i, currPtr - i, numberOffset.BitIndex);
}
else
{
moveSumsWithShift64bit(lastPtr - i, currPtr - i, numberOffset.BitIndex);
}
}
ulong affter = currPtr[-iterations] << numberOffset.BitIndex;
lastPtr[-iterations] |= affter;
}
}
}
private static void CreateAllSums(int number, BitArraySlim currSums, PartialSumsData data)
{
data.Sums = CreatePartialSums(new int[] { number }, currSums, data);
data.SumsCount = BoolArrayTrueCount(data.Sums);
}
internal void Push(BitArraySlim arr)
{
Arrays.Push(arr);
}