public VideoCaptureByJPEGInstance(VideoCaptureByJPEGDefinition theDefinition, TestExecution testExecution)
: base(theDefinition, testExecution)
{
mCamera = theDefinition.Camera;
mFrameTimeout = theDefinition.FrameTimeout;
mStopConditionTimeout = theDefinition.StopConditionTimeout;
mCapturedVideo = new GeneratedVideoInstance(theDefinition.ResultantVideo, testExecution);
}
protected override void OnDoWork(DoWorkEventArgs e)
{
mHttpCameraUser.mWorkerLogMessage = "snapshot worker kicked off"; mHttpCameraUser.mWorkerLogMessageAvailable = true;
VideoCaptureByJPEGDefinition defObject = (VideoCaptureByJPEGDefinition)mHttpCameraUser.Definition();
int readSize = 1024;
int bufferSize = defObject.bufferSize;
byte[] buffer = defObject.bufferForWorker;
HttpWebRequest request = null;
WebResponse response = null;
Stream stream = null;
Random randomNumberGenerator = new Random((int)DateTime.Now.Ticks);
HttpRequestCachePolicy bypassCachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.BypassCache);
try
{
while (true) // loop "indefinitely" grabbing frames until whomever started this worker(thread) cancels it
{
string uri = mHttpCameraUser.Camera.CompleteImageRequestURL();
if (mHttpCameraUser.Camera.ProxyCacheProtection)
{
uri += ((uri.IndexOf('?') == -1) ? '?' : '&') + "proxyprevention=" + randomNumberGenerator.Next().ToString();
}
request = (HttpWebRequest)WebRequest.Create(uri);
request.CachePolicy = bypassCachePolicy;
request.Timeout = mHttpCameraUser.FrameTimeout;
if (mHttpCameraUser.Camera.Login != null && mHttpCameraUser.Camera.Login.Length > 0)
{
if (mHttpCameraUser.Camera.Password == null)
{
mHttpCameraUser.Camera.Password = String.Empty;
}
request.Credentials = new NetworkCredential(mHttpCameraUser.Camera.Login, mHttpCameraUser.Camera.Password);
}
// setting ConnectionGroupName to make sure we don't run out of connections amongst all the cameras (see http://msdn2.microsoft.com/en-us/library/ms998562.aspx section: "Connections")
request.ConnectionGroupName = mHttpCameraUser.TestSequence().Name + " : " + mHttpCameraUser.Name; // a unique group for each HTTP user within each TestSequence. We don't want to create unique groups every request because that would be inefficient
// TODO: check maxconnection attribute in Machine.config (limits the number of concurrent outbound calls)
///////////
response = request.GetResponse();
stream = response.GetResponseStream();
long contentLength = response.ContentLength;
int bytesRead = 0;
int totalBytesRead = 0;
//ReportProgress(0, "Requesting image");
bool done = false;
while (!done)
{
if (CancellationPending)
{
e.Cancel = true;
return;
}
if (totalBytesRead > bufferSize - readSize)
{
e.Result = ResultCodes.BufferTooSmall;
return;
}
bytesRead = stream.Read(buffer, totalBytesRead, readSize);
if (bytesRead == 0)
{
done = true;
}
else
{
totalBytesRead += bytesRead;
//ReportProgress((int)(bytesRead * 100 / contentLength), "Downloading...");
}
}
mImage = (Bitmap)Bitmap.FromStream(new MemoryStream(buffer, 0, totalBytesRead));
mHttpCameraUser.ProcessNewImage(mImage);
}
// we never get here since the while loop never terminates...we exit the loop on worker cancellation (above) or an exception (below)
}
catch (WebException exception)
{
switch (exception.Status)
{
// http://msdn2.microsoft.com/en-us/library/system.net.webexceptionstatus(vs.80).aspx
case WebExceptionStatus.Timeout:
e.Result = ResultCodes.Timeout;
break;
default:
e.Result = ResultCodes.Unspecified;
break;
}
}
catch (Exception exception)
{
e.Result = ResultCodes.NonWebException;
}
finally
{
if (request != null)
{
request.Abort();
request = null;
}
if (stream != null)
{
stream.Close();
stream = null;
}
if (response != null)
{
response.Close();
response = null;
}
}
}