public ArchiveFetch(TimeInfo timeInfo, List<PointPair> valueList)
{
this.TimeInfo = timeInfo;
this.ValueList = valueList;
}
public ArchiveFetch(TimeInfo timeInfo, List <PointPair> valueList)
{
this.TimeInfo = timeInfo;
this.ValueList = valueList;
}
/// <summary>
/// Fetch data from a single archive. Note that checks for validity of the time
/// period requested happen above this level so it's possible to wrap around the
/// archive on a read and request data older than the archive's retention
/// </summary>
private static ArchiveFetch ArchiveFetch(FileStream fh, ArchiveInfo archive, long fromTime, long untilTime)
{
Debug.WriteLine(string.Format("ArchiveFetch from {0} to {1} in archive [{2},{3}]", fromTime, untilTime, archive.SecondsPerPoint, archive.Points));
var fromInterval = (fromTime - (fromTime.Mod(archive.SecondsPerPoint))) + (int)archive.SecondsPerPoint;
var untilInterval = (untilTime - (untilTime.Mod(archive.SecondsPerPoint))) + (int)archive.SecondsPerPoint;
fh.Seek(archive.Offset, SeekOrigin.Begin);
using (var reader = new EndianBinaryReader(EndianBitConverter.Big, new NonClosingStreamWrapper(fh)))
{
var baseInterval = reader.ReadInt64(); // timestamp
var baseValue = reader.ReadDouble(); // value
if (baseInterval == 0)
{
var step = archive.SecondsPerPoint;
var points = (int)((untilInterval - fromInterval) / step);
var _timeInfo = new TimeInfo(fromInterval, untilInterval, archive.SecondsPerPoint);
var _valueList = Enumerable.Repeat(new PointPair(0, 0), points).ToList();
return(new ArchiveFetch(_timeInfo, _valueList));
}
// Determine fromOffset
var timeDistance = fromInterval - baseInterval;
var pointDistance = timeDistance / archive.SecondsPerPoint;
var byteDistance = pointDistance * PointSize;
var fromOffset = (int)(archive.Offset + (byteDistance.Mod(archive.Size)));
// Determine untilOffset
timeDistance = untilInterval - baseInterval;
pointDistance = timeDistance / archive.SecondsPerPoint;
byteDistance = pointDistance * PointSize;
var untilOffset = (int)(archive.Offset + (byteDistance.Mod(archive.Size)));
// read all the points in the interval
fh.Seek(fromOffset, SeekOrigin.Begin);
byte[] seriesBuffer;
int bytesRead = 0;
if (fromOffset < untilOffset)
{
// If we don't wrap around the archive
seriesBuffer = new byte[(int)(untilOffset - fromOffset)];
bytesRead += fh.Read(seriesBuffer, 0, seriesBuffer.Length);
if (bytesRead != seriesBuffer.Length)
{
throw new CorruptWhisperFileException(string.Format("read: {0} != {1}", bytesRead, seriesBuffer.Length));
}
Debug.WriteLine(string.Format("read {0} points starting at offset {1}", (bytesRead / PointSize), fromOffset));
}
else
{
// We do wrap around the archive, so we need two reads
var archiveEnd = archive.Offset + archive.Size;
var firstPart = (int)(archiveEnd - fromOffset);
var secondPart = (int)(untilOffset - archive.Offset);
seriesBuffer = new byte[firstPart + secondPart];
bytesRead += fh.Read(seriesBuffer, 0, firstPart);
Debug.WriteLine(string.Format("read {0} points starting at offset {1}", (firstPart / PointSize), fromOffset));
fh.Seek(archive.Offset, SeekOrigin.Begin);
bytesRead += fh.Read(seriesBuffer, firstPart, secondPart);
Debug.WriteLine(string.Format("read {0} points starting at offset {1}", (secondPart / PointSize), archive.Offset));
}
var valueList = UnpackSeriesBuffer(seriesBuffer, bytesRead);
var timeInfo = new TimeInfo(fromInterval, untilInterval, archive.SecondsPerPoint);
return(new ArchiveFetch(timeInfo, valueList.Where(x => !x.Equals(default(PointPair)) && x.Timestamp != default(long)).ToList()));
}
}
/// <summary>
/// Fetch data from a single archive. Note that checks for validity of the time
/// period requested happen above this level so it's possible to wrap around the
/// archive on a read and request data older than the archive's retention
/// </summary>
private static ArchiveFetch ArchiveFetch(FileStream fh, ArchiveInfo archive, long fromTime, long untilTime)
{
Debug.WriteLine(string.Format("ArchiveFetch from {0} to {1} in archive [{2},{3}]", fromTime, untilTime, archive.SecondsPerPoint, archive.Points));
var fromInterval = (fromTime - (fromTime.Mod(archive.SecondsPerPoint))) + (int)archive.SecondsPerPoint;
var untilInterval = (untilTime - (untilTime.Mod(archive.SecondsPerPoint))) + (int)archive.SecondsPerPoint;
fh.Seek(archive.Offset, SeekOrigin.Begin);
using (var reader = new EndianBinaryReader(EndianBitConverter.Big, new NonClosingStreamWrapper(fh)))
{
var baseInterval = reader.ReadInt64(); // timestamp
var baseValue = reader.ReadDouble(); // value
if (baseInterval == 0)
{
var step = archive.SecondsPerPoint;
var points = (int)((untilInterval - fromInterval) / step);
var _timeInfo = new TimeInfo(fromInterval, untilInterval, archive.SecondsPerPoint);
var _valueList = Enumerable.Repeat(new PointPair(0, 0), points).ToList();
return new ArchiveFetch(_timeInfo, _valueList);
}
// Determine fromOffset
var timeDistance = fromInterval - baseInterval;
var pointDistance = timeDistance / archive.SecondsPerPoint;
var byteDistance = pointDistance * PointSize;
var fromOffset = (int)(archive.Offset + (byteDistance.Mod(archive.Size)));
// Determine untilOffset
timeDistance = untilInterval - baseInterval;
pointDistance = timeDistance / archive.SecondsPerPoint;
byteDistance = pointDistance * PointSize;
var untilOffset = (int)(archive.Offset + (byteDistance.Mod(archive.Size)));
// read all the points in the interval
fh.Seek(fromOffset, SeekOrigin.Begin);
byte[] seriesBuffer;
int bytesRead = 0;
if (fromOffset < untilOffset)
{
// If we don't wrap around the archive
seriesBuffer = new byte[(int)(untilOffset - fromOffset)];
bytesRead += fh.Read(seriesBuffer, 0, seriesBuffer.Length);
if (bytesRead != seriesBuffer.Length)
{
throw new CorruptWhisperFileException(string.Format("read: {0} != {1}", bytesRead, seriesBuffer.Length));
}
Debug.WriteLine(string.Format("read {0} points starting at offset {1}", (bytesRead / PointSize), fromOffset));
}
else
{
// We do wrap around the archive, so we need two reads
var archiveEnd = archive.Offset + archive.Size;
var firstPart = (int)(archiveEnd - fromOffset);
var secondPart = (int)(untilOffset - archive.Offset);
seriesBuffer = new byte[firstPart + secondPart];
bytesRead += fh.Read(seriesBuffer, 0, firstPart);
Debug.WriteLine(string.Format("read {0} points starting at offset {1}", (firstPart / PointSize), fromOffset));
fh.Seek(archive.Offset, SeekOrigin.Begin);
bytesRead += fh.Read(seriesBuffer, firstPart, secondPart);
Debug.WriteLine(string.Format("read {0} points starting at offset {1}", (secondPart / PointSize), archive.Offset));
}
var valueList = UnpackSeriesBuffer(seriesBuffer, bytesRead);
var timeInfo = new TimeInfo(fromInterval, untilInterval, archive.SecondsPerPoint);
return new ArchiveFetch(timeInfo, valueList.Where(x => !x.Equals(default(PointPair)) && x.Timestamp != default(long)).ToList());
}
}
