/// <summary>
/// Encode this histogram in compressed form into a <see cref="ByteBuffer"/>.
/// </summary>
/// <param name="source">The histogram to encode</param>
/// <param name="targetBuffer">The buffer to write to</param>
/// <returns>The number of bytes written to the buffer</returns>
public static int EncodeIntoCompressedByteBuffer(this HistogramBase source, ByteBuffer targetBuffer)
{
int neededCapacity = source.GetNeededByteBufferCapacity();
var intermediateUncompressedByteBuffer = ByteBuffer.Allocate(neededCapacity);
source.Encode(intermediateUncompressedByteBuffer, HistogramEncoderV2.Instance);
int initialTargetPosition = targetBuffer.Position;
targetBuffer.PutInt(source.GetCompressedEncodingCookie());
int compressedContentsHeaderPosition = targetBuffer.Position;
targetBuffer.PutInt(0); // Placeholder for compressed contents length
var compressedDataLength = targetBuffer.CompressedCopy(intermediateUncompressedByteBuffer, targetBuffer.Position);
targetBuffer.PutInt(compressedContentsHeaderPosition, compressedDataLength); // Record the compressed length
int bytesWritten = compressedDataLength + 8;
targetBuffer.Position = (initialTargetPosition + bytesWritten);
return(bytesWritten);
}
