/// <inheritdoc/>
public static Protobuf.TimeSeriesFrame Compress(this Protobuf.TimeSeriesFrame frame)
{
ByteString payload;
switch (frame.PayloadCase)
{
case Protobuf.TimeSeriesFrame.PayloadOneofCase.UncompressedPayload:
payload = ByteString.CopyFrom(Ionic.Zlib.ZlibStream.CompressBuffer(frame.UncompressedPayload.ToByteArray()));
break;
case Protobuf.TimeSeriesFrame.PayloadOneofCase.CompressedPayload:
payload = frame.CompressedPayload;
break;
case Protobuf.TimeSeriesFrame.PayloadOneofCase.None:
payload = null;
break;
default:
throw new Exception();
}
return(new Protobuf.TimeSeriesFrame(frame)
{
CompressedPayload = payload
});
}
/// <summary>
///
/// </summary>
/// <param name="dataPoints"></param>
/// <returns></returns>
public static IEnumerable <byte> Compress(IEnumerable <DataPoint <dynamic> > dataPoints)
{
if (dataPoints.Select(_ => _.TimeSeries).Distinct().Count() > 1)
{
throw new Exception("Unable to compress data points: All data points must come from the same time series.");
}
var timeSeries = ByteString.CopyFrom(dataPoints.First().TimeSeries.Value.ToByteArray());
var firstTimestamp = dataPoints.First().Timestamp.Value;
var protobufDataPoints = dataPoints.Select(_ => _.ToProtobuf()).ToArray();
var frame = new Protobuf.TimeSeriesFrame {
TimeSeries = timeSeries, Timestamp = (ulong)firstTimestamp
};
var payload = new Protobuf.TimeSeriesPayload();
payload = payload.Append(protobufDataPoints);
frame.UncompressedPayload = payload;
frame = frame.Compress();
var encoded = frame.ToByteArray();
byte[] length = BitConverter.GetBytes((int)encoded.Length);
return(length.Concat(encoded));
}
/// <inheritdoc/>
public static IEnumerable <DataPoint <dynamic> > DataPoints(this Protobuf.TimeSeriesFrame frame)
{
var timeSeriesId = new Guid(frame.TimeSeries.ToByteArray());
frame = frame.Uncompress();
var timestamps = frame.UncompressedPayload.Timestep
.Aggregate((IEnumerable <long>) new List <long> {
(long)frame.Timestamp
}, (offsets, step) => offsets.Append(offsets.Last() + (long)step))
.Skip(1);
var values = frame.UncompressedPayload.Values?.Value;
var longitudes = frame.UncompressedPayload.Coordinates?.Longitudes;
var latitudes = frame.UncompressedPayload.Coordinates?.Latitudes;
var coordinates = longitudes?.Zip(latitudes, (longitude, latitude) => new Coordinate {
Longitude = new Measurement <float> {
Value = longitude
}, Latitude = new Measurement <float> {
Value = latitude
}
});
IEnumerable <DataPoint <dynamic> > dataPoints;
switch (frame.UncompressedPayload.PayloadCase)
{
case Protobuf.TimeSeriesPayload.PayloadOneofCase.Values:
dataPoints = timestamps.Zip(values, (timestamp, value) => new DataPoint <dynamic> {
TimeSeries = timeSeriesId, Timestamp = timestamp, Value = value
});
break;
case Protobuf.TimeSeriesPayload.PayloadOneofCase.Coordinates:
dataPoints = timestamps.Zip(coordinates, (timestamp, coordinate) => new DataPoint <dynamic> {
TimeSeries = timeSeriesId, Timestamp = timestamp, Value = coordinate
});
break;
default:
throw new Exception();
}
return(dataPoints);
}
