/// <summary>
/// Starts a task that is responsible for deserializing all non-path events as fed to it through the specified queue
/// </summary>
/// <param name="nonPathEventsToDeserialize">The queue where non-path events (as file positions) to deserialize will be fed</param>
/// <returns>A task that will finish when the queue that it consumes from is both marked completed and empty</returns>
private Task CreateNonPathEventConsumerTask(BlockingCollection <long> nonPathEventsToDeserialize)
{
return(Task.Run(() =>
{
using (FileStream fileStream = File.Open(m_logFilename, FileMode.Open, FileAccess.Read, FileShare.Read))
{
ParallelEventReader parallelEventReader = new ParallelEventReader(this, fileStream);
while (!nonPathEventsToDeserialize.IsCompleted)
{
// Get next event file position
long positionToDeserialize;
try
{
positionToDeserialize = nonPathEventsToDeserialize.Take();
}
catch (InvalidOperationException)
{
// This exception is thrown when CompleteAdding is called while we are blocked on the call to Take
// If we see this exception, we know we are done processing events and the task can exit
return;
}
// Seek to the start of the next event to deserialize
fileStream.Seek(positionToDeserialize, SeekOrigin.Begin);
EventHeader header = EventHeader.ReadFrom(parallelEventReader);
// Ensure that event id is NOT an AddPath event
Contract.Assert((BinaryLogger.LogSupportEventId)header.EventId != BinaryLogger.LogSupportEventId.AddPath);
var startOfNextEvent = fileStream.Position + header.EventPayloadSize;
// Handle the internal events
if (header.EventId < (uint)BinaryLogger.LogSupportEventId.Max)
{
switch ((BinaryLogger.LogSupportEventId)header.EventId)
{
case BinaryLogger.LogSupportEventId.StartTime:
ReadStartTimeEvent(parallelEventReader);
break;
case BinaryLogger.LogSupportEventId.AddStringId:
ReadStringIdEvent(parallelEventReader);
break;
}
Contract.Assert(fileStream.Position == startOfNextEvent);
continue;
}
else
{
header.EventId -= (uint)BinaryLogger.LogSupportEventId.Max;
}
EventHandler handler;
if ((m_handlers.Length > header.EventId) &&
((handler = m_handlers[header.EventId]) != null))
{
handler(header.EventId, header.WorkerId, header.Timestamp, parallelEventReader);
Contract.Assert(fileStream.Position <= startOfNextEvent, "Event handler read beyond the event payload");
}
}
}
}));
}
