public override void GetStreamValuesHandler(GetStreamValuesArgsReader request, StreamValueCollectionsDTOWriter response)
{
TimestampPointerDTO?exclusiveUpperBoundCell = GetTimestampCellAfterTime(request.StreamCellId, request.EndTime);
TimestampPointerDTO?inclusiveUpperBoundCellNullable;
if (exclusiveUpperBoundCell.HasValue)
{
inclusiveUpperBoundCellNullable = GetImmediatePredecessorTimestampCell(exclusiveUpperBoundCell.Value.Id);
}
else
{
inclusiveUpperBoundCellNullable = GetSnapshotTimestamp(request.StreamCellId);
}
if (!inclusiveUpperBoundCellNullable.HasValue)
{
return;
}
TimestampPointerDTO inclusiveUpperBoundCell = inclusiveUpperBoundCellNullable.Value;
foreach (var valueCollection in GetValuesAfterTimestamp(request.StreamCellId, request.StartTime, inclusiveUpperBoundCell))
{
response.ValueCollections.Add(valueCollection);
}
}
private TimestampPointerDTO GetTimestampCellAfterTimeRecursive(TimestampPointerDTO currentTimeCellDTO, long timestamp)
{
TimestampPointerDTO previousTimeCellDTO = GetPreviousTimestampCellId(currentTimeCellDTO, timestamp);
if (previousTimeCellDTO.Id == currentTimeCellDTO.Id)
{
return(currentTimeCellDTO);
}
else
{
return(GetTimestampCellAfterTime(previousTimeCellDTO, timestamp)); // logN
}
}
private TimestampPointerDTO GetTimestampCellAfterTime(TimestampPointerDTO currentTimeCellDTO, long timestamp)
{
TimestampPointerDTO previousTimeCellDTO;
while (true)
{
previousTimeCellDTO = GetPreviousTimestampCellId(currentTimeCellDTO, timestamp);
if (previousTimeCellDTO.Id == currentTimeCellDTO.Id)
{
break;
}
currentTimeCellDTO = previousTimeCellDTO;
}
return(currentTimeCellDTO);
}
private TimestampPointerDTO?GetTimestampCellAfterTime(long streamCellId, long timestamp)
{
TimestampPointerDTO?snapshotNullable = GetSnapshotTimestamp(streamCellId);
//Empty stream, return empty
if (!snapshotNullable.HasValue)
{
return(null);
}
//Requested time is after Snapshot time; return Snapshot value
TimestampPointerDTO snapshot = snapshotNullable.Value;
if (timestamp >= snapshot.Ticks)
{
return(snapshot);
}
//Request time is historical; search through history
return(GetTimestampCellAfterTime(snapshot, timestamp));
}
public static void Apply(this StreamValueCollectionDTOWriter response, TimestampPointerDTO timestamp, long streamCellId)
{
response.Timestamp = timestamp.Ticks;
response.StreamCellId = streamCellId;
List <long> valueCellIds;
using (var valuesCollection = Global.LocalStorage.UseStreamValueCollection(timestamp.Values))
{
valueCellIds = valuesCollection.Values;
}
foreach (var valueCellId in valueCellIds)
{
using (var value = Global.LocalStorage.UseStreamValue(valueCellId))
{
StreamValueDTO valueDTO = value.ToStreamValueDTO();
response.Values.Add(valueDTO);
}
}
}
private TimestampPointerDTO GetPreviousTimestampCellId(TimestampPointerDTO currentCell, long referenceTicks)
{
List <long> previousTimeCellIds = currentCell.Previous;
long previousTimeCellId = previousTimeCellIds[0];
for (int i = previousTimeCellIds.Count - 1; i >= 0; i--)
{
previousTimeCellId = previousTimeCellIds[i];
using (var previousTimeCell = Storage.UseTimestamp(previousTimeCellId, CellAccessOptions.ReturnNullOnCellNotFound))
{
if (previousTimeCell == null)
{
continue;
}
if (previousTimeCell.Ticks > referenceTicks)
{
return(previousTimeCell.ToTimestampPointerDTO());
}
}
}
return(currentCell);
}
private IEnumerable <StreamValueCollectionDTO> GetValuesAfterTimestamp(long streamCellId, long inclusiveLowerBoundTimestamp, TimestampPointerDTO inclusiveUpperBoundCell)
{
TimestampPointerDTO?currentCell = inclusiveUpperBoundCell;
while (currentCell.HasValue && currentCell.Value.Ticks >= inclusiveLowerBoundTimestamp)
{
List <StreamValueDTO> valuesDTO = DTOFactory.GetValues(currentCell.Value.Values);
StreamValueCollectionDTO valuesCollectionDTO = new StreamValueCollectionDTO(valuesDTO, currentCell.Value.Ticks, streamCellId);
yield return(valuesCollectionDTO);
currentCell = GetImmediatePredecessorTimestampCell(currentCell.Value.Id);
}
}
