private void InitializeTraceHandle()
{
if (this.traceHandle.id < 0)
{
// initializing for reading traces with iterator at oldest trace event so we can query the total number of events lost in the session.
StringBuilder sbPath = new StringBuilder();
sbPath.Append(this.path);
// trace is always initialized with first and last events since
// the timerange is always reset for each ReadEvents call
LttngReaderStatusCode res = LttngReaderBindings.initialize_trace_processing(
sbPath,
(ulong)LTTngTraceTimestampFlag.FIRST_TRACE_TIMESTAMP,
(ulong)LTTngTraceTimestampFlag.LAST_TRACE_TIMESTAMP,
out this.traceHandle);
if (res != LttngReaderStatusCode.SUCCESS)
{
string errorMessage = LttngReaderStatusMessage.GetMessage(res);
throw new InvalidDataException($"{errorMessage}. Occured while trying to initialize processing of LTTng traces for folder {this.path}");
}
this.EventsLost = (uint)this.traceHandle.trace_info.events_lost;
}
}
public void ReadEvents(DateTime startTime, DateTime endTime)
{
if (startTime > endTime)
{
throw new ArgumentException(StringResources.ETLReaderError_StartTimeGreaterThanEndTime, "startTime");
}
if (this.EventRead == null)
{
throw new InvalidOperationException(StringResources.ETLReaderError_NoSubscribersForEventRead);
}
// initialize trace handle
InitializeTraceHandle();
ulong eventReadFailureCount;
LttngReaderStatusCode res = ProcessTrace(startTime, endTime, ref this.traceHandle, out eventReadFailureCount);
if (res != LttngReaderStatusCode.SUCCESS && res != LttngReaderStatusCode.END_OF_TRACE)
{
string errorMessage = LttngReaderStatusMessage.GetMessage(res);
throw new InvalidDataException(
$"{errorMessage}. When processing traces at folder: {this.path}.\n" +
$"Last event successfully read has timestamp: {LttngTraceFolderEventReader.ConvertFromUnixEpoch(this.lastEventReadTimestamp).ToString("o")}\n" +
$"Total events events skipped due to failure before exception : {eventReadFailureCount}");
}
if (eventReadFailureCount != 0)
{
throw new InvalidDataException(
$"Failed to read {eventReadFailureCount} events from trace at {this.path}" +
$"StartTime: {startTime}, EndTime: {endTime}");
}
}