/// <summary>
/// Interprets a byte buffer as a set of lines and enqueues them as events.
/// </summary>
/// <param name="data">The buffer.</param>
/// <param name="bytesRead">Size of the data in the buffer.</param>
private void ProduceEvents(byte[] data, int bytesRead)
{
TEvent currentEvent = default(TEvent);
// generate new lines from a buffer's worth of asynchronously read data
IEnumerator <string> lines = this.ByteArrayToLines(data, bytesRead).GetEnumerator();
// move to the first line, if there is one at all
if (!lines.MoveNext())
{
return;
}
// each line corresponds to an event - enqueue them
do
{
// account for empty lines (owing to possible \n as starting character)
if (0 == lines.Current.Length)
{
continue;
}
currentEvent = this.CreateEventFromLine(lines.Current);
if (currentEvent == null)
{
// something went wrong there
this.Cleanup();
return;
}
EnqueueOperationResult result = this.inputAdapter.Enqueue(ref currentEvent);
if (EnqueueOperationResult.Full == result)
{
this.inputAdapter.ReleaseEvent(ref currentEvent);
this.inputAdapter.Ready();
// wait to be resumed
this.readyToEnqueue.WaitOne();
return;
}
} while (lines.MoveNext());
// kick off the next reading cycle
this.AsyncReadEventData();
}
/// <summary>
/// Reads rows from the SQL source, and enqueues each row as an event into StreamInsight
/// </summary>
private void ProduceEvents()
{
while (true)
{
// if the engine asked the adapter to stop
if (this.inputAdapter.AdapterState == AdapterState.Stopping)
{
// cleanup state
this.Cleanup();
// inform the engine that the adapter has stopped
this.inputAdapter.Stopped();
// exit the worker thread
return;
}
// prepare the event - either saved from previous iteration, or a new one from the input
if (this.currentEvent == null)
{
// read a row
// IMPORTANT: If a runtime exception during Read inhibits a call to Cleanup(),
// resources will be released by Dispose() during adapter shutdown.
if (!this.dataReader.Read())
{
this.Cleanup();
// inform the engine that the adapter has stopped
this.inputAdapter.Stopped();
return;
}
// create an event from the row
this.currentEvent = this.CreateEventFromRow(this.dataReader);
if (this.currentEvent == null)
{
this.Cleanup();
// inform the engine that the adapter has stopped
this.inputAdapter.Stopped();
return;
}
}
// Enqueue the created event into the engine
EnqueueOperationResult result = this.inputAdapter.Enqueue(ref this.currentEvent);
// If the engine pushes back, the adapter is Suspended; so do this ..
if (result == EnqueueOperationResult.Full)
{
// retain the currentEvent to be handled in the next iteration
// inform the engine that the adapter is Ready to be Resumed
this.inputAdapter.Ready();
// exit the worker thread
return;
}
}
}
