public double ReadNextValue()
{
var nonZeroValue = _buffer.ReadValue(1);
if (nonZeroValue == 0)
{
return(BitConverter.Int64BitsToDouble(_previousValue));
}
var usePreviousBlockInfo = _buffer.ReadValue(1);
long xorValue;
if (usePreviousBlockInfo == 1)
{
xorValue = ( long )_buffer.ReadValue(_previousBlockInfo.BlockSize);
xorValue <<= _previousBlockInfo.TrailingZeros;
}
else
{
int leadingZeros = (int)_buffer.ReadValue(Constants.LeadingZerosLengthBits);
int blockSize = (int)_buffer.ReadValue(Constants.BlockSizeLengthBits) + Constants.BlockSizeAdjustment;
int trailingZeros = 64 - blockSize - leadingZeros;
xorValue = ( long )_buffer.ReadValue(blockSize);
xorValue <<= trailingZeros;
_previousBlockInfo = new BlockInfo(leadingZeros, trailingZeros);
}
long value = xorValue ^ _previousValue;
_previousValue = value;
return(BitConverter.Int64BitsToDouble(value));
}
public DateTime ReadNextDateTime()
{
if (_hasReadFirstValue == false)
{
var unixTime = (int)_buffer.ReadValue(Constants.BitsForFirstTimestamp);
_previousTimestamp = unixTime;
_previousTimestampDelta = Constants.DefaultDelta;
_hasReadFirstValue = true;
return(FromUnixTime(unixTime));
}
var type = _buffer.FindTheFirstZeroBit(TimestampEncodingDetails.MaxControlBitLength);
if (type > 0)
{
// Delta of delta is non zero. Calculate the new delta. "index" will
// be used to find the right encoding.
int index = type - 1;
var encoding = TimestampEncodingDetails.Encodings[index];
long decodedValue = (long)_buffer.ReadValue(encoding.BitsForValue);
// [0, 255] becomes [-128, 127]
decodedValue -= encoding.MaxValueForEncoding;
if (decodedValue >= 0)
{
// [-128, 127] becomes [-128, 128] without the zero in the middle
decodedValue++;
}
_previousTimestampDelta += ( int )decodedValue;
}
_previousTimestamp += _previousTimestampDelta;
return(FromUnixTime(_previousTimestamp));
}