/// <summary>
/// Parses provided string representation of <see cref="IntX" /> object.
/// </summary>
/// <param name="value">Number as string.</param>
/// <param name="startIndex">Index inside string from which to start.</param>
/// <param name="endIndex">Index inside string on which to end.</param>
/// <param name="numberBase">Number base.</param>
/// <param name="charToDigits">Char->digit dictionary.</param>
/// <param name="digitsRes">Resulting digits.</param>
/// <returns>Parsed integer length.</returns>
public uint Parse(string value, int startIndex, int endIndex, uint numberBase, IDictionary <char, uint> charToDigits, uint[] digitsRes)
{
// Calculate length of input string
int bitsInChar = Bits.Msb(numberBase);
uint valueLength = (uint)(endIndex - startIndex + 1);
ulong valueBitLength = (ulong)valueLength * (ulong)bitsInChar;
// Calculate needed digits length and first shift
uint digitsLength = (uint)(valueBitLength / Constants.DigitBitCount) + 1;
uint digitIndex = digitsLength - 1;
int initialShift = (int)(valueBitLength % Constants.DigitBitCount);
// Probably correct digits length
if (initialShift == 0)
{
--digitsLength;
}
// Do parsing in big cycle
uint digit;
for (int i = startIndex; i <= endIndex; ++i)
{
digit = StrRepHelper.GetDigit(charToDigits, value[i], numberBase);
// Correct initial digit shift
if (initialShift == 0)
{
// If shift is equals to zero then char is not on digit elemtns bounds,
// so just go to the previous digit
initialShift = Constants.DigitBitCount - bitsInChar;
--digitIndex;
}
else
{
// Here shift might be negative, but it's okay
initialShift -= bitsInChar;
}
// Insert new digit in correct place
digitsRes[digitIndex] |= initialShift < 0 ? digit >> -initialShift : digit << initialShift;
// In case if shift was negative we also must modify previous digit
if (initialShift < 0)
{
initialShift += Constants.DigitBitCount;
digitsRes[--digitIndex] |= digit << initialShift;
}
}
if (digitsRes[digitsLength - 1] == 0)
{
--digitsLength;
}
return(digitsLength);
}
/// <summary>
/// Parses provided string representation of <see cref="IntX" /> object.
/// </summary>
/// <param name="value">Number as string.</param>
/// <param name="startIndex">Index inside string from which to start.</param>
/// <param name="endIndex">Index inside string on which to end.</param>
/// <param name="numberBase">Number base.</param>
/// <param name="charToDigits">Char->digit dictionary.</param>
/// <param name="digitsRes">Resulting digits.</param>
/// <returns>Parsed integer length.</returns>
override public uint Parse(string value, int startIndex, int endIndex, uint numberBase, IDictionary <char, uint> charToDigits, uint[] digitsRes)
{
uint newLength = base.Parse(value, startIndex, endIndex, numberBase, charToDigits, digitsRes);
// Maybe base method already parsed this number
if (newLength != 0)
{
return(newLength);
}
// Do parsing in big cycle
ulong numberBaseLong = numberBase;
ulong digit;
for (int i = startIndex; i <= endIndex; ++i)
{
digit = StrRepHelper.GetDigit(charToDigits, value[i], numberBase);
// Next multiply existing values by base and add this value to them
if (newLength == 0)
{
if (digit != 0)
{
digitsRes[0] = (uint)digit;
newLength = 1;
}
}
else
{
for (uint j = 0; j < newLength; ++j)
{
digit += digitsRes[j] * numberBaseLong;
digitsRes[j] = (uint)digit;
digit >>= 32;
}
if (digit != 0)
{
digitsRes[newLength++] = (uint)digit;
}
}
}
return(newLength);
}
/// <summary>
/// Parses provided string representation of <see cref="IntX" /> object.
/// </summary>
/// <param name="value">Number as string.</param>
/// <param name="startIndex">Index inside string from which to start.</param>
/// <param name="endIndex">Index inside string on which to end.</param>
/// <param name="numberBase">Number base.</param>
/// <param name="charToDigits">Char->digit dictionary.</param>
/// <param name="digitsRes">Resulting digits.</param>
/// <returns>Parsed integer length.</returns>
override unsafe public uint Parse(string value, int startIndex, int endIndex, uint numberBase, IDictionary <char, uint> charToDigits, uint[] digitsRes)
{
uint newLength = base.Parse(value, startIndex, endIndex, numberBase, charToDigits, digitsRes);
// Maybe base method already parsed this number
if (newLength != 0)
{
return(newLength);
}
// Check length - maybe use classic parser instead
uint initialLength = (uint)digitsRes.LongLength;
if (initialLength < Constants.FastParseLengthLowerBound || initialLength > Constants.FastParseLengthUpperBound)
{
return(_classicParser.Parse(value, startIndex, endIndex, numberBase, charToDigits, digitsRes));
}
uint valueLength = (uint)(endIndex - startIndex + 1);
uint digitsLength = 1U << Bits.CeilLog2(valueLength);
// Prepare array for digits in other base
uint[] valueDigits = ArrayPool <uint> .Instance.GetArray(digitsLength);
// This second array will store integer lengths initially
uint[] valueDigits2 = ArrayPool <uint> .Instance.GetArray(digitsLength);
fixed(uint *valueDigitsStartPtr = valueDigits, valueDigitsStartPtr2 = valueDigits2)
{
// In the string first digit means last in digits array
uint *valueDigitsPtr = valueDigitsStartPtr + valueLength - 1;
uint *valueDigitsPtr2 = valueDigitsStartPtr2 + valueLength - 1;
// Reverse copy characters into digits
fixed(char *valueStartPtr = value)
{
char *valuePtr = valueStartPtr + startIndex;
char *valueEndPtr = valuePtr + valueLength;
for (; valuePtr < valueEndPtr; ++valuePtr, --valueDigitsPtr, --valueDigitsPtr2)
{
// Get digit itself - this call will throw an exception if char is invalid
*valueDigitsPtr = StrRepHelper.GetDigit(charToDigits, *valuePtr, numberBase);
// Set length of this digit (zero for zero)
*valueDigitsPtr2 = *valueDigitsPtr == 0U ? 0U : 1U;
}
}
// We have retrieved lengths array from pool - it needs to be cleared before using
DigitHelper.SetBlockDigits(valueDigitsStartPtr2 + valueLength, digitsLength - valueLength, 0);
// Now start from the digit arrays beginning
valueDigitsPtr = valueDigitsStartPtr;
valueDigitsPtr2 = valueDigitsStartPtr2;
// Current multiplier (classic or fast) will be used
IMultiplier multiplier = MultiplyManager.GetCurrentMultiplier();
// Here base in needed power will be stored
IntX baseInt = null;
// Temporary variables used on swapping
uint[] tempDigits;
uint * tempPtr;
// Variables used in cycle
uint *ptr1, ptr2, valueDigitsPtrEnd;
uint loLength, hiLength;
// Outer cycle instead of recursion
for (uint innerStep = 1, outerStep = 2; innerStep < digitsLength; innerStep <<= 1, outerStep <<= 1)
{
// Maybe baseInt must be multiplied by itself
baseInt = baseInt == null ? numberBase : baseInt * baseInt;
// Using unsafe here
fixed(uint *baseDigitsPtr = baseInt._digits)
{
// Start from arrays beginning
ptr1 = valueDigitsPtr;
ptr2 = valueDigitsPtr2;
// vauleDigits array end
valueDigitsPtrEnd = valueDigitsPtr + digitsLength;
// Cycle thru all digits and their lengths
for (; ptr1 < valueDigitsPtrEnd; ptr1 += outerStep, ptr2 += outerStep)
{
// Get lengths of "lower" and "higher" value parts
loLength = *ptr2;
hiLength = *(ptr2 + innerStep);
if (hiLength != 0)
{
// We always must clear an array before multiply
DigitHelper.SetBlockDigits(ptr2, outerStep, 0U);
// Multiply per baseInt
hiLength = multiplier.Multiply(
baseDigitsPtr,
baseInt._length,
ptr1 + innerStep,
hiLength,
ptr2);
}
// Sum results
if (hiLength != 0 || loLength != 0)
{
*ptr1 = DigitOpHelper.Add(
ptr2,
hiLength,
ptr1,
loLength,
ptr2);
}
else
{
*ptr1 = 0U;
}
}
}
// After inner cycle valueDigits will contain lengths and valueDigits2 will contain actual values
// so we need to swap them here
tempDigits = valueDigits;
valueDigits = valueDigits2;
valueDigits2 = tempDigits;
tempPtr = valueDigitsPtr;
valueDigitsPtr = valueDigitsPtr2;
valueDigitsPtr2 = tempPtr;
}
}
// Determine real length of converted number
uint realLength = valueDigits2[0];
// Copy to result
Array.Copy(valueDigits, digitsRes, realLength);
// Return arrays to pool
ArrayPool <uint> .Instance.AddArray(valueDigits);
ArrayPool <uint> .Instance.AddArray(valueDigits2);
return(realLength);
}