private bool IncrementBuffer()
{
// increment the buffer we use....
int bufIndex = (curBufIndex+1) % bufferCount;
while (bufIndex != curBufIndex)
{
if (buffers[bufIndex].Available == true)
{
curBufIndex = bufIndex;
currentBuffer = buffers[curBufIndex];
return true;
}
bufIndex = ( bufIndex+1 ) % bufferCount;
}
// no buffers available so grow...
if (bufferCount < buffers.Length)
{
eventLog.WriteEntry("Growing buffers for stream " + streamID + " to " + (bufferCount+1), EventLogEntryType.Warning,
ArchiveServiceEventLog.ID.GrowingBuffers );
bufIndex = bufferCount;
bufferCount++;
buffers[bufIndex] = new BufferManager (bufIndex, streamID);
buffers[bufIndex].Overflowed += new EventHandler(this.OnOverflowException);
perfCounter.AddInstanceForCollection( buffers[bufIndex] );
curBufIndex = bufIndex;
currentBuffer = buffers[curBufIndex];
return true;
}
else
{
// Uut of buffers logged in return. Also, we return w/o having changed which buffer is the current
// one b/c we expect the next buffer to be the first one to become available.
return false;
}
}
/// <summary>
/// setup the initial buffers and write the basic stream data to the db
/// </summary>
/// <param name="participant">for this participant</param>
/// <param name="stream">using this rtp stream</param>
public StreamManager( int participantID, RtpStream stream, ConferenceRecorderPC conferencePerfCounter )
{
this.rtpStream = stream;
this.perfCounter = conferencePerfCounter;
this.partID = participantID;
// We do *not* re-use existing streams if a stream goes away and comes back. This decision was made
// becuase it causes the client not to see the Rtcp data die & come back during playback, though it
// did during recording. This inconsistency was viewed to cause problems, and was removed.
InitStream();
buffers = new BufferManager[Constants.MaxBuffers];
bufferCount = Constants.InitialBuffers;
for ( int i = 0; i < bufferCount; i++)
{
buffers[i] = new BufferManager( i, streamID );
buffers[i].Overflowed += new EventHandler(this.OnOverflowException);
perfCounter.AddInstanceForCollection(buffers[i]);
}
curBufIndex = 0;
currentBuffer = buffers[curBufIndex];
rtpStream.FrameReceived += new MSR.LST.Net.Rtp.RtpStream.FrameReceivedEventHandler(FrameReceived);
}
private void ProcessFrame(object argument)
{
lock (this)
{
FrameWithTicks frame = (FrameWithTicks)argument;
this.receivedBytes = this.receivedBytes + (long)frame.frame.Length;
++receivedFrames;
// Verify the frame fits in a buffer. If not, write it to the database directly.
if (frame.frame.Length < Constants.BufferSize)
{
// if there is no room in the current buffer
if (!currentBuffer.HasRoom(frame.frame.Length))
{
// With bufferAvailable we try to prevent writing the dropped frame event to the EventLog too often
// Incidentally, that means we'll be writing once per every time we use up the buffer pool. If we
// have a sudden flood of data, that means it'll only get written once or twice, which helps perf.
bool bufferAvailable = false;
if (currentBuffer.Available)
{
currentBuffer.EnableWrite();
++writtenBuffers;
bufferAvailable = true;
}
if (!IncrementBuffer())
{
// Discard the packet by doing nothing with it
if (bufferAvailable)
{
// Warn the user
eventLog.WriteEntry("Dropping a frame in StreamManager::OnFrameReceived due to no buffers being available.",
EventLogEntryType.Error, ArchiveServiceEventLog.ID.FrameDropped);
}
++droppedFrames;
return;
}
}
currentBuffer.AddFrame(frame);
}
else
{
Trace.WriteLine("Writing frame directly to disk. Frame size: " + frame.frame.Length);
// Force pending data to be written to disk
if (currentBuffer.Available)
{
currentBuffer.EnableWrite();
++writtenBuffers;
}
// Get our new buffer
IncrementBuffer();
// And write this frame directly to disk
BufferManager.DirectWrite(frame, this.streamID);
}
++writtenFrames;
}
}
