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}" +
$"StartTime: {startTime}, EndTime: {endTime}");
}
}
public LttngTraceFolderEventReader(string path)
{
if (!Directory.Exists(path))
{
throw new DirectoryNotFoundException($"LTTng trace folder not found at: {path}");
}
this.path = path;
LttngTraceFolderEventReader.clearLTTngTraceHandle(ref this.traceHandle);
}
public TraceSessionMetadata ReadTraceSessionMetadata()
{
// initialize trace handle
InitializeTraceHandle();
// This is an approximation based on the naming of the file.
var traceSessionName = Path.GetFileName(this.path).Split('_')[0];
var eventsLost = (this.TestEventsLost > 0) ? (this.TestEventsLost) : (this.EventsLost);
var sessionStartTime = LttngTraceFolderEventReader.ConvertFromUnixEpoch(this.traceHandle.trace_info.start_time);
var sessionEndTime = LttngTraceFolderEventReader.ConvertFromUnixEpoch(this.traceHandle.trace_info.end_time);
var traceSessionMetadata = new TraceSessionMetadata(traceSessionName, eventsLost, sessionStartTime, sessionEndTime);
return(traceSessionMetadata);
}
private LttngReaderStatusCode ProcessTrace(DateTime startTime, DateTime endTime, ref LTTngTraceHandle traceHandle, out ulong eventReadFailureCount)
{
EventRecord eventRecord = new EventRecord();
ulong lastReadTimestamp = 0;
// needed for processing unstructured events in Linux
bool isUnstructured = false;
StringBuilder unstructuredRecord = new StringBuilder(LttngReaderBindings.MAX_LTTNG_UNSTRUCTURED_EVENT_LEN + 1);
StringBuilder taskNameEventName = new StringBuilder(LttngReaderBindings.MAX_LTTNG_TASK_EVENT_NAME_LEN + 1);
ulong startTimeEpochNanoS = LttngTraceFolderEventReader.ConvertToUnixEpoch(startTime);
ulong endTimeEpochNanoS = LttngTraceFolderEventReader.ConvertToUnixEpoch(endTime);
// set start and end time for reading traces
LttngReaderStatusCode res = LttngReaderBindings.set_start_end_time(ref traceHandle, startTimeEpochNanoS, endTimeEpochNanoS);
eventReadFailureCount = 0;
if (res != LttngReaderStatusCode.SUCCESS)
{
return(res);
}
res = LttngReaderBindings.read_next_event(ref traceHandle, ref eventRecord, unstructuredRecord, taskNameEventName, ref lastReadTimestamp, ref isUnstructured);
while (res == LttngReaderStatusCode.SUCCESS || res == LttngReaderStatusCode.FAILED_TO_READ_EVENT)
{
if (res == LttngReaderStatusCode.FAILED_TO_READ_EVENT)
{
eventReadFailureCount++;
continue;
}
EventRecordEventArgs eventRecordEventArgs;
this.lastEventReadTimestamp = lastReadTimestamp;
if (isUnstructured)
{
try
{
eventRecord.EventHeader.TimeStamp = LttngTraceFolderEventReader.ConvertFromUnixEpoch(lastReadTimestamp).ToFileTimeUtc();
}
catch (Exception)
{
// Flagging error with minimum timestamp so we can continue processing other events.
eventRecord.EventHeader.TimeStamp = 0;
}
eventRecordEventArgs = new EventRecordEventArgs(eventRecord);
eventRecordEventArgs.IsUnstructured = isUnstructured;
eventRecordEventArgs.TaskNameEventName = taskNameEventName.ToString();
eventRecordEventArgs.UnstructuredRecord = unstructuredRecord.ToString();
}
else
{
eventRecordEventArgs = new EventRecordEventArgs(eventRecord);
}
this.EventRead(this, eventRecordEventArgs);
if (eventRecordEventArgs.Cancel)
{
return(LttngReaderStatusCode.SUCCESS);
}
res = LttngReaderBindings.read_next_event(ref traceHandle, ref eventRecord, unstructuredRecord, taskNameEventName, ref lastReadTimestamp, ref isUnstructured);
}
return(res);
}
