public override async Task <ResponseMessage> ReadNextAsync(CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
TryCatch <CrossPartitionChangeFeedAsyncEnumerator> monadicEnumerator = await this.lazyMonadicEnumerator.GetValueAsync(cancellationToken);
if (monadicEnumerator.Failed)
{
Exception createException = monadicEnumerator.Exception;
CosmosException cosmosException = ExceptionToCosmosException.CreateFromException(createException);
return(new ResponseMessage(
cosmosException.StatusCode,
requestMessage: null,
headers: cosmosException.Headers,
cosmosException: cosmosException,
diagnostics: new CosmosDiagnosticsContextCore()));
}
CrossPartitionChangeFeedAsyncEnumerator enumerator = monadicEnumerator.Result;
if (!await enumerator.MoveNextAsync())
{
throw new InvalidOperationException("ChangeFeed enumerator should always have a next continuation");
}
if (enumerator.Current.Failed)
{
CosmosException cosmosException = ExceptionToCosmosException.CreateFromException(enumerator.Current.Exception);
if (!IsRetriableException(cosmosException))
{
this.hasMoreResults = false;
}
return(new ResponseMessage(
cosmosException.StatusCode,
requestMessage: null,
headers: cosmosException.Headers,
cosmosException: cosmosException,
diagnostics: new CosmosDiagnosticsContextCore()));
}
CrossFeedRangePage <Pagination.ChangeFeedPage, ChangeFeedState> crossFeedRangePage = enumerator.Current.Result;
Pagination.ChangeFeedPage changeFeedPage = crossFeedRangePage.Page;
ResponseMessage responseMessage;
if (changeFeedPage is Pagination.ChangeFeedSuccessPage changeFeedSuccessPage)
{
responseMessage = new ResponseMessage(statusCode: System.Net.HttpStatusCode.OK)
{
Content = changeFeedSuccessPage.Content
};
}
else
{
responseMessage = new ResponseMessage(statusCode: System.Net.HttpStatusCode.NotModified);
}
CrossFeedRangeState <ChangeFeedState> crossFeedRangeState = crossFeedRangePage.State;
string continuationToken;
if (this.changeFeedRequestOptions.EmitOldContinuationToken)
{
List <CompositeContinuationToken> compositeContinuationTokens = new List <CompositeContinuationToken>();
for (int i = 0; i < crossFeedRangeState.Value.Length; i++)
{
FeedRangeState <ChangeFeedState> changeFeedFeedRangeState = crossFeedRangeState.Value.Span[i];
string token = changeFeedFeedRangeState.State is ChangeFeedStateContinuation changeFeedStateContinuation ? ((CosmosString)changeFeedStateContinuation.ContinuationToken).Value : null;
Documents.Routing.Range <string> range = ((FeedRangeEpk)changeFeedFeedRangeState.FeedRange).Range;
CompositeContinuationToken compositeContinuationToken = new CompositeContinuationToken()
{
Range = range,
Token = token,
};
compositeContinuationTokens.Add(compositeContinuationToken);
}
FeedRangeCompositeContinuation feedRangeCompositeContinuationToken = new FeedRangeCompositeContinuation(
await this.documentContainer.GetResourceIdentifierAsync(cancellationToken),
FeedRangeEpk.FullRange,
compositeContinuationTokens);
continuationToken = feedRangeCompositeContinuationToken.ToString();
}
else
{
ChangeFeedCrossFeedRangeState changeFeedCrossFeedRangeState = new ChangeFeedCrossFeedRangeState(crossFeedRangeState.Value);
continuationToken = VersionedAndRidCheckedCompositeToken.ToCosmosElement(
new VersionedAndRidCheckedCompositeToken(
VersionedAndRidCheckedCompositeToken.Version.V2,
changeFeedCrossFeedRangeState.ToCosmosElement(),
await this.documentContainer.GetResourceIdentifierAsync(cancellationToken))).ToString();
}
responseMessage.Headers.ContinuationToken = continuationToken;
responseMessage.Headers.RequestCharge = changeFeedPage.RequestCharge;
responseMessage.Headers.ActivityId = changeFeedPage.ActivityId;
return(responseMessage);
}
private async Task <ResponseMessage> ReadNextInternalAsync(ITrace trace, CancellationToken cancellationToken = default)
{
if (trace == null)
{
throw new ArgumentNullException(nameof(trace));
}
TryCatch <CrossPartitionChangeFeedAsyncEnumerator> monadicEnumerator = await this.lazyMonadicEnumerator.GetValueAsync(trace, cancellationToken);
if (monadicEnumerator.Failed)
{
Exception createException = monadicEnumerator.Exception;
if (!ExceptionToCosmosException.TryCreateFromException(
createException,
trace,
out CosmosException cosmosException))
{
// Initialization issue, there are no enumerators to invoke
this.hasMoreResults = false;
throw createException;
}
return(new ResponseMessage(
cosmosException.StatusCode,
requestMessage: null,
headers: cosmosException.Headers,
cosmosException: cosmosException,
trace: trace));
}
CrossPartitionChangeFeedAsyncEnumerator enumerator = monadicEnumerator.Result;
enumerator.SetCancellationToken(cancellationToken);
try
{
if (!await enumerator.MoveNextAsync(trace))
{
throw new InvalidOperationException("ChangeFeed enumerator should always have a next continuation");
}
}
catch (OperationCanceledException ex) when(!(ex is CosmosOperationCanceledException))
{
throw new CosmosOperationCanceledException(ex, trace);
}
if (enumerator.Current.Failed)
{
if (!ExceptionToCosmosException.TryCreateFromException(
enumerator.Current.Exception,
trace,
out CosmosException cosmosException))
{
throw ExceptionWithStackTraceException.UnWrapMonadExcepion(enumerator.Current.Exception, trace);
}
if (!IsRetriableException(cosmosException))
{
this.hasMoreResults = false;
}
return(new ResponseMessage(
cosmosException.StatusCode,
requestMessage: null,
headers: cosmosException.Headers,
cosmosException: cosmosException,
trace: trace));
}
CrossFeedRangePage <Pagination.ChangeFeedPage, ChangeFeedState> crossFeedRangePage = enumerator.Current.Result;
Pagination.ChangeFeedPage changeFeedPage = crossFeedRangePage.Page;
ResponseMessage responseMessage;
if (changeFeedPage is Pagination.ChangeFeedSuccessPage changeFeedSuccessPage)
{
responseMessage = new ResponseMessage(statusCode: System.Net.HttpStatusCode.OK)
{
Content = changeFeedSuccessPage.Content
};
}
else
{
responseMessage = new ResponseMessage(statusCode: System.Net.HttpStatusCode.NotModified);
}
CrossFeedRangeState <ChangeFeedState> crossFeedRangeState = crossFeedRangePage.State;
ChangeFeedCrossFeedRangeState changeFeedCrossFeedRangeState = new ChangeFeedCrossFeedRangeState(crossFeedRangeState.Value);
string continuationToken = VersionedAndRidCheckedCompositeToken.ToCosmosElement(
new VersionedAndRidCheckedCompositeToken(
VersionedAndRidCheckedCompositeToken.Version.V2,
changeFeedCrossFeedRangeState.ToCosmosElement(),
await this.documentContainer.GetResourceIdentifierAsync(trace, cancellationToken))).ToString();
responseMessage.Headers.ContinuationToken = continuationToken;
responseMessage.Headers.RequestCharge = changeFeedPage.RequestCharge;
responseMessage.Headers.ActivityId = changeFeedPage.ActivityId;
responseMessage.Trace = trace;
return(responseMessage);
}