/// <summary>
/// Creates a new empty TimeSeriesStreamCollection object. It initializes an underlying MemoryStream and
/// inits it with default values for all TimeSeries (one for each given key is created). Every write access
/// to any TimeSeries will then be in-place on the already allocated buffer with the fixed size of
/// keys.Count * bucketCount.
/// </summary>
public TimeSeriesStreamCollection(IEnumerable <TKey> keys, int keySize, Action <TKey, Stream> writeKeyAction, TimeSeriesSpan span, int decimalPlaces = 1) : base()
{
var keyList = keys.ToList();
Metrics = new BinaryStreamMetrics(keySize, span.Count, decimalPlaces);
_stream = new CompressableMemoryStream(Metrics.StreamSize(keyList.Count));
_stream.SetLength(Metrics.StreamSize(keyList.Count));
using (var writer = new BinaryWriter(_stream, System.Text.Encoding.UTF8, true))
writer.Write(keyList.Count);
foreach (var i in Enumerable.Range(0, keyList.Count))
{
writeKeyAction(keyList[i], _stream);
var timeseries = new TimeSeriesStream <T>(_stream, Metrics.TimeseriesPosition(i), span, decimalPlaces);
foreach (var item in timeseries)
{
timeseries[item.Key] = null;
}
_dict.Add(keyList[i], timeseries);
}
}
/// <summary>
/// Initializes a CompressableMemoryStream from a GZipped byte array.
/// </summary>
public static CompressableMemoryStream FromCompressedByteArray(byte[] byteArray)
{
var stream = new CompressableMemoryStream((int)(byteArray.Length / _compressionEstimate));
using var compressedStream = new MemoryStream(byteArray, 0, byteArray.Length, false)
{
Position = 0
};
using var decompressionStream = new GZipStream(compressedStream, CompressionMode.Decompress);
decompressionStream.CopyTo(stream);
stream.Position = 0;
return(stream);
}
/// <summary>
/// Restores a TimeSeriesStreamCollection from a compressed byte array.
/// </summary>
public TimeSeriesStreamCollection(byte[] compressedByteArray, int keySize, Func <Stream, TKey> readKeyFunc, TimeSeriesSpan span, int decimalPlaces = 1) : base()
{
Metrics = new BinaryStreamMetrics(keySize, span.Count, decimalPlaces);
_stream = CompressableMemoryStream.FromCompressedByteArray(compressedByteArray);
int count = 0;
using (var reader = new BinaryReader(_stream, System.Text.Encoding.UTF8, true))
count = reader.ReadInt32();
foreach (var i in Enumerable.Range(0, count))
{
_stream.Seek(Metrics.KeyPosition(i), SeekOrigin.Begin);
var key = readKeyFunc(_stream);
_dict.Add(key, new TimeSeriesStream <T>(_stream, Metrics.TimeseriesPosition(i), span, decimalPlaces));
}
}
