/// <summary>
/// Waits for a condition to be satisfied.
/// </summary>
/// <typeparam name="T">
/// The changeType of object that will be operated on.
/// </typeparam>
/// <param name="client">
/// The client instance this is extending.
/// </param>
/// <param name="poll">
/// The function to poll the client for state.
/// </param>
/// <param name="continuePolling">
/// A function to evaluate the state to see if it matches the condition.
/// </param>
/// <param name="notifyHandler">
/// A notification handler used to rais events when the status changes.
/// </param>
/// <param name="interval">
/// A time frame to wait between polls.
/// </param>
/// <param name="timeout">
/// The amount of time to wait for the condition to be satisfied.
/// </param>
/// <param name="cancellationToken">
/// A Cancelation Token that can be used to cancel the request.
/// </param>
/// <returns>
/// An awaitable task.
/// </returns>
public static async Task WaitForCondition <T>(this IHDInsightManagementPocoClient client, Func <Task <T> > poll, Func <T, PollResult> continuePolling, Action <T> notifyHandler, TimeSpan interval, TimeSpan timeout, CancellationToken cancellationToken)
{
client.ArgumentNotNull("client");
poll.ArgumentNotNull("poll");
continuePolling.ArgumentNotNull("continuePolling");
var start = DateTime.Now;
int pollingFailures = 0;
const int MaxPollingFailuresCount = 10;
T pollingResult = default(T);
PollResult result = PollResult.Continue;
do
{
try
{
pollingResult = await poll();
result = continuePolling(pollingResult);
if (notifyHandler.IsNotNull() && pollingResult.IsNotNull())
{
notifyHandler(pollingResult);
}
if (result == PollResult.Unknown || result == PollResult.Null)
{
pollingFailures++;
if (result == PollResult.Null)
{
client.LogMessage("Poll for cluster returned no cluster. Current error weight (out of 10): " + pollingFailures.ToString(CultureInfo.InvariantCulture),
Severity.Informational,
Verbosity.Diagnostic);
}
cancellationToken.WaitForInterval(interval);
}
else if (result == PollResult.Continue)
{
pollingFailures = 0;
cancellationToken.WaitForInterval(interval);
}
}
catch (Exception ex)
{
ex = ex.GetFirstException();
var hlex = ex as HttpLayerException;
var httpEx = ex as HttpRequestException;
var webex = ex as WebException;
var timeOut = ex as TimeoutException;
var taskCancled = ex as TaskCanceledException;
var operationCanceled = ex as OperationCanceledException;
if (taskCancled.IsNotNull() && taskCancled.CancellationToken.IsNotNull() && taskCancled.CancellationToken.IsCancellationRequested)
{
throw;
}
if (operationCanceled.IsNotNull() && operationCanceled.CancellationToken.IsNotNull() && operationCanceled.CancellationToken.IsCancellationRequested)
{
throw;
}
if (hlex.IsNotNull() || httpEx.IsNotNull() || webex.IsNotNull() || taskCancled.IsNotNull() || timeOut.IsNotNull() || operationCanceled.IsNotNull())
{
pollingFailures += 5;
client.LogMessage("Poll for cluster a manageable exception. Current error weight (out of 10): " + pollingFailures.ToString(CultureInfo.InvariantCulture),
Severity.Informational,
Verbosity.Diagnostic);
client.LogMessage(ex.ToString(), Severity.Informational, Verbosity.Diagnostic);
if (pollingFailures >= MaxPollingFailuresCount)
{
client.LogMessage("Polling error weight exceeded maximum allowed. Aborting operation.", Severity.Error, Verbosity.Normal);
throw;
}
}
else
{
client.LogMessage("Poll for cluster returned an unmanageable exception. Aborting operation.", Severity.Error, Verbosity.Normal);
client.LogException(ex);
throw;
}
}
}while ((result == PollResult.Continue || result == PollResult.Null || result == PollResult.Unknown) &&
DateTime.Now - start < timeout &&
pollingFailures <= MaxPollingFailuresCount);
if (pollingFailures > MaxPollingFailuresCount)
{
client.LogMessage("Polling error weight exceeded maximum allowed. Aborting operation.", Severity.Error, Verbosity.Normal);
}
if (notifyHandler.IsNotNull() && pollingResult.IsNotNull())
{
notifyHandler(pollingResult);
}
}