/// <summary>
/// Get the next set of results from the cosmos service
/// </summary>
/// <param name="cancellationToken">(Optional) <see cref="CancellationToken"/> representing request cancellation.</param>
/// <returns>A query response from cosmos service</returns>
public override async Task <ResponseMessage> ReadNextAsync(CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
if (!this.hasMoreResults)
{
throw new InvalidOperationException("Should not be calling FeedIterator that does not have any more results");
}
if (this.monadicEnumerator.Failed)
{
this.hasMoreResults = false;
CosmosException cosmosException = ExceptionToCosmosException.CreateFromException(this.monadicEnumerator.Exception);
return(new ResponseMessage(
statusCode: System.Net.HttpStatusCode.BadRequest,
requestMessage: null,
headers: cosmosException.Headers,
cosmosException: cosmosException,
diagnostics: cosmosException.DiagnosticsContext));
}
CrossPartitionReadFeedAsyncEnumerator enumerator = this.monadicEnumerator.Result;
TryCatch <ReadFeedPage> monadicPage;
try
{
if (!await enumerator.MoveNextAsync())
{
throw new InvalidOperationException("Should not be calling enumerator that does not have any more results");
}
monadicPage = enumerator.Current;
}
catch (Exception ex)
{
monadicPage = TryCatch <ReadFeedPage> .FromException(ex);
}
if (monadicPage.Failed)
{
CosmosException cosmosException = ExceptionToCosmosException.CreateFromException(monadicPage.Exception);
if (!IsRetriableException(cosmosException))
{
this.hasMoreResults = false;
}
return(new ResponseMessage(
statusCode: cosmosException.StatusCode,
requestMessage: null,
headers: cosmosException.Headers,
cosmosException: cosmosException,
diagnostics: cosmosException.DiagnosticsContext));
}
ReadFeedPage readFeedPage = monadicPage.Result;
if (readFeedPage.State == default)
{
this.hasMoreResults = false;
}
// Make the continuation token match the older format:
string continuationToken;
if (readFeedPage.State != null)
{
List <CompositeContinuationToken> compositeContinuationTokens = new List <CompositeContinuationToken>();
CosmosArray compositeContinuationTokensCosmosArray = (CosmosArray)readFeedPage.State.ContinuationToken;
foreach (CosmosElement arrayItem in compositeContinuationTokensCosmosArray)
{
ReadFeedContinuationToken readFeedContinuationToken = ReadFeedContinuationToken.MonadicConvertFromCosmosElement(arrayItem).Result;
FeedRangeEpk feedRangeEpk = (FeedRangeEpk)readFeedContinuationToken.Range;
ReadFeedState readFeedState = readFeedContinuationToken.State;
CompositeContinuationToken compositeContinuationToken = new CompositeContinuationToken()
{
Range = feedRangeEpk.Range,
Token = readFeedState.ContinuationToken.ToString(),
};
compositeContinuationTokens.Add(compositeContinuationToken);
}
FeedRangeCompositeContinuation feedRangeCompositeContinuation = new FeedRangeCompositeContinuation(
containerRid: string.Empty,
feedRange: FeedRangeEpk.FullRange,
compositeContinuationTokens);
continuationToken = feedRangeCompositeContinuation.ToString();
}
else
{
continuationToken = null;
}
return(new ResponseMessage(
statusCode: System.Net.HttpStatusCode.OK,
requestMessage: default,
public ReadFeedIteratorCore(
IDocumentContainer documentContainer,
QueryRequestOptions queryRequestOptions,
string continuationToken,
int pageSize,
CancellationToken cancellationToken)
{
if (!string.IsNullOrEmpty(continuationToken))
{
bool isNewArrayFormat = (continuationToken.Length >= 2) && (continuationToken[0] == '[') && (continuationToken[continuationToken.Length - 1] == ']');
if (!isNewArrayFormat)
{
// One of the two older formats
if (!FeedRangeContinuation.TryParse(continuationToken, out FeedRangeContinuation feedRangeContinuation))
{
// Backward compatible with old format
feedRangeContinuation = new FeedRangeCompositeContinuation(
containerRid: string.Empty,
FeedRangeEpk.FullRange,
new List <Documents.Routing.Range <string> >()
{
new Documents.Routing.Range <string>(
Documents.Routing.PartitionKeyInternal.MinimumInclusiveEffectivePartitionKey,
Documents.Routing.PartitionKeyInternal.MaximumExclusiveEffectivePartitionKey,
isMinInclusive: true,
isMaxInclusive: false)
},
continuationToken);
}
// need to massage it a little
string oldContinuationFormat = feedRangeContinuation.ToString();
CosmosObject cosmosObject = CosmosObject.Parse(oldContinuationFormat);
CosmosArray continuations = (CosmosArray)cosmosObject["Continuation"];
List <CosmosElement> readFeedContinuationTokens = new List <CosmosElement>();
foreach (CosmosElement continuation in continuations)
{
CosmosObject continuationObject = (CosmosObject)continuation;
CosmosObject rangeObject = (CosmosObject)continuationObject["range"];
string min = ((CosmosString)rangeObject["min"]).Value;
string max = ((CosmosString)rangeObject["max"]).Value;
CosmosElement token = CosmosElement.Parse(((CosmosString)continuationObject["token"]).Value);
FeedRangeInternal feedRange = new FeedRangeEpk(new Documents.Routing.Range <string>(min, max, isMinInclusive: true, isMaxInclusive: false));
ReadFeedState state = new ReadFeedState(token);
ReadFeedContinuationToken readFeedContinuationToken = new ReadFeedContinuationToken(feedRange, state);
readFeedContinuationTokens.Add(ReadFeedContinuationToken.ToCosmosElement(readFeedContinuationToken));
}
CosmosArray cosmosArrayContinuationTokens = CosmosArray.Create(readFeedContinuationTokens);
continuationToken = cosmosArrayContinuationTokens.ToString();
}
}
this.monadicEnumerator = CrossPartitionReadFeedAsyncEnumerator.MonadicCreate(
documentContainer,
queryRequestOptions,
continuationToken: continuationToken,
pageSize,
cancellationToken);
this.hasMoreResults = true;
}
