private static long GetCountAtIndex(int idx, IRecordedData data)
{
return data.Counts[idx];
//var normalizedIdx = NormalizeIndex(idx, data.NormalizingIndexOffset, data.Counts.Length);
//return data.Counts[idx];
}
/// <summary>
/// Encodes the supplied <see cref="IRecordedData"/> into the supplied <see cref="ByteBuffer"/>.
/// </summary>
/// <param name="data">The data to encode.</param>
/// <param name="buffer">The target <see cref="ByteBuffer"/> to write to.</param>
/// <returns>The number of bytes written.</returns>
public int Encode(IRecordedData data, ByteBuffer buffer)
{
int initialPosition = buffer.Position;
buffer.PutInt(data.Cookie);
int payloadLengthPosition = buffer.Position;
buffer.PutInt(0); // Placeholder for payload length in bytes.
buffer.PutInt(data.NormalizingIndexOffset);
buffer.PutInt(data.NumberOfSignificantValueDigits);
buffer.PutLong(data.LowestDiscernibleValue);
buffer.PutLong(data.HighestTrackableValue);
buffer.PutDouble(data.IntegerToDoubleValueConversionRatio);
var payloadLength = FillBufferFromCountsArray(buffer, data);
buffer.PutInt(payloadLengthPosition, payloadLength);
var bytesWritten = buffer.Position - initialPosition;
return bytesWritten;
}
/// <summary>
/// Encodes the supplied <see cref="IRecordedData"/> into the supplied <see cref="ByteBuffer"/>.
/// </summary>
/// <param name="data">The data to encode.</param>
/// <param name="buffer">The target <see cref="ByteBuffer"/> to write to.</param>
/// <returns>The number of bytes written.</returns>
public int Encode(IRecordedData data, ByteBuffer buffer)
{
int initialPosition = buffer.Position;
buffer.PutInt(data.Cookie);
int payloadLengthPosition = buffer.Position;
buffer.PutInt(0); // Placeholder for payload length in bytes.
buffer.PutInt(data.NormalizingIndexOffset);
buffer.PutInt(data.NumberOfSignificantValueDigits);
buffer.PutLong(data.LowestDiscernibleValue);
buffer.PutLong(data.HighestTrackableValue);
buffer.PutDouble(data.IntegerToDoubleValueConversionRatio);
var payloadLength = FillBufferFromCountsArray(buffer, data);
buffer.PutInt(payloadLengthPosition, payloadLength);
var bytesWritten = buffer.Position - initialPosition;
return(bytesWritten);
}
private static int FillBufferFromCountsArray(ByteBuffer buffer, IRecordedData data)
{
int startPosition = buffer.Position;
int srcIndex = 0;
while (srcIndex < data.Counts.Length)
{
// V2 encoding format uses a ZigZag LEB128-64b9B encoded long.
// Positive values are counts, while negative values indicate a repeat zero counts. i.e. -4 indicates 4 sequential buckets with 0 counts.
long count = GetCountAtIndex(srcIndex++, data);
if (count < 0)
{
throw new InvalidOperationException($"Cannot encode histogram containing negative counts ({count}) at index {srcIndex}");
}
// Count trailing 0s (which follow this count):
long zerosCount = 0;
if (count == 0)
{
zerosCount = 1;
while ((srcIndex < data.Counts.Length) && (GetCountAtIndex(srcIndex, data) == 0))
{
zerosCount++;
srcIndex++;
}
}
if (zerosCount > 1)
{
ZigZagEncoding.PutLong(buffer, -zerosCount);
}
else
{
ZigZagEncoding.PutLong(buffer, count);
}
}
return(buffer.Position - startPosition);
}
private static int FillBufferFromCountsArray(ByteBuffer buffer, IRecordedData data)
{
int startPosition = buffer.Position;
int srcIndex = 0;
while (srcIndex < data.Counts.Length)
{
// V2 encoding format uses a ZigZag LEB128-64b9B encoded long.
// Positive values are counts, while negative values indicate a repeat zero counts. i.e. -4 indicates 4 sequential buckets with 0 counts.
long count = GetCountAtIndex(srcIndex++, data);
if (count < 0)
{
throw new InvalidOperationException($"Cannot encode histogram containing negative counts ({count}) at index {srcIndex}");
}
// Count trailing 0s (which follow this count):
long zerosCount = 0;
if (count == 0)
{
zerosCount = 1;
while ((srcIndex < data.Counts.Length) && (GetCountAtIndex(srcIndex, data) == 0))
{
zerosCount++;
srcIndex++;
}
}
if (zerosCount > 1)
{
ZigZagEncoding.PutLong(buffer, -zerosCount);
}
else
{
ZigZagEncoding.PutLong(buffer, count);
}
}
return buffer.Position - startPosition;
}
private static long GetCountAtIndex(int idx, IRecordedData data)
{
return(data.Counts[idx]);
//var normalizedIdx = NormalizeIndex(idx, data.NormalizingIndexOffset, data.Counts.Length);
//return data.Counts[idx];
}
