/// <summary>
/// Starts observing commits and dispatching them..
/// </summary>
/// <returns></returns>
public async Task Start()
{
if (_isStarted.EnsureCalledOnce())
{
return;
}
string checkpointToken = await _checkpointRepository.Get();
/* string checkpointToken = null;
* await _retryPolicy.Retry(async () => checkpointToken = await _checkpointRepository.Get(), _disposed.Token); //TODO should have different retry policy? */
_subscription = _eventStoreClient.Subscribe(checkpointToken, async commit =>
{
try
{
await _retryPolicy.Retry(() => _dispatchCommit(commit, _disposed.Token), _disposed.Token);
await _retryPolicy.Retry(() => _checkpointRepository.Put(commit.CheckpointToken), _disposed.Token);
}
catch (Exception ex)
{
Logger.ErrorException(
Messages.ExceptionHasOccuredWhenDispatchingACommit.FormatWith(commit.ToString()),
ex);
_projectedCommits.OnError(ex);
throw;
}
_projectedCommits.OnNext(commit);
});
}
public void When_non_transient_exception_thrown_then_should_retry()
{
var sut = new TransientExceptionRetryPolicy(TimeSpan.FromMilliseconds(1), TimeSpan.FromMilliseconds(10));
Func <Task> act = () => sut.Retry(() => { throw new Exception(); }, CancellationToken.None);
act.ShouldThrow <Exception>();
}
public void When_non_transient_exception_thrown_then_should_retry()
{
var sut = new TransientExceptionRetryPolicy(TimeSpan.FromMilliseconds(1), TimeSpan.FromMilliseconds(10));
Func<Task> act = () => sut.Retry(() => { throw new Exception(); }, CancellationToken.None);
act.ShouldThrow<Exception>();
}
public void When_transient_exception_thrown_indefinitely_then_should_repeatedly_retry_until_duration_and_then_throw()
{
var duration = TimeSpan.FromSeconds(1);
var stopwatch = Stopwatch.StartNew();
var sut = new TransientExceptionRetryPolicy(TimeSpan.FromMilliseconds(1), duration);
int count = 0;
Func <Task> act = () => sut.Retry(() =>
{
count++;
throw new TransientException();
}, CancellationToken.None);
act.ShouldThrow <TransientException>();
count.Should().BeGreaterThan(1);
stopwatch.Elapsed.Should().BeGreaterThan(duration);
}
public void When_transient_exception_thrown_indefinitely_then_should_repeatedly_retry_until_duration_and_then_throw()
{
var duration = TimeSpan.FromSeconds(1);
var stopwatch = Stopwatch.StartNew();
var sut = new TransientExceptionRetryPolicy(TimeSpan.FromMilliseconds(1), duration);
int count = 0;
Func<Task> act = () => sut.Retry(() =>
{
count++;
throw new TransientException();
}, CancellationToken.None);
act.ShouldThrow<TransientException>();
count.Should().BeGreaterThan(1);
stopwatch.Elapsed.Should().BeGreaterThan(duration);
}
public async Task When_transient_exception_thrown_once_then_should_retry()
{
var sut = new TransientExceptionRetryPolicy(TimeSpan.FromMilliseconds(1), TimeSpan.FromSeconds(1));
int count = 0;
var tcs = new TaskCompletionSource <bool>();
await sut.Retry(() =>
{
count++;
if (count == 2)
{
tcs.SetResult(true);
return(Task.FromResult(0));
}
throw new TransientException();
}, CancellationToken.None);
await tcs.Task;
count.Should().Be(2);
}
public async Task When_transient_exception_thrown_once_then_should_retry()
{
var sut = new TransientExceptionRetryPolicy(TimeSpan.FromMilliseconds(1), TimeSpan.FromSeconds(1));
int count = 0;
var tcs = new TaskCompletionSource<bool>();
await sut.Retry(() =>
{
count++;
if (count == 2)
{
tcs.SetResult(true);
return Task.FromResult(0);
}
throw new TransientException();
}, CancellationToken.None);
await tcs.Task;
count.Should().Be(2);
}