internal async Task <Tuple <string, ResponseMessage> > ReadNextInternalAsync(ITrace trace, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
if (trace == null)
{
throw new ArgumentNullException(nameof(trace));
}
if (this.compositeContinuationToken == null)
{
PartitionKeyRangeCache pkRangeCache = await this.clientContext.DocumentClient.GetPartitionKeyRangeCacheAsync();
this.containerRid = await this.container.GetCachedRIDAsync(
forceRefresh : false,
trace,
cancellationToken : cancellationToken);
this.compositeContinuationToken = await StandByFeedContinuationToken.CreateAsync(
this.containerRid,
this.continuationToken,
pkRangeCache.TryGetOverlappingRangesAsync);
}
(CompositeContinuationToken currentRangeToken, string rangeId) = await this.compositeContinuationToken.GetCurrentTokenAsync();
string partitionKeyRangeId = rangeId;
this.continuationToken = currentRangeToken.Token;
ResponseMessage response = await this.NextResultSetDelegateAsync(this.continuationToken, partitionKeyRangeId, this.maxItemCount, this.changeFeedOptions, trace, cancellationToken);
if (await this.ShouldRetryFailureAsync(response, cancellationToken))
{
return(await this.ReadNextInternalAsync(trace, cancellationToken));
}
if (response.IsSuccessStatusCode ||
response.StatusCode == HttpStatusCode.NotModified)
{
// Change Feed read uses Etag for continuation
currentRangeToken.Token = response.Headers.ETag;
}
return(new Tuple <string, ResponseMessage>(partitionKeyRangeId, response));
}
public static string CreateForRange(
string containerRid,
string minInclusive,
string maxExclusive)
{
if (string.IsNullOrWhiteSpace(containerRid))
{
throw new ArgumentNullException(nameof(containerRid));
}
// MinInclusive can be an empty string
if (minInclusive == null)
{
throw new ArgumentNullException(nameof(minInclusive));
}
if (string.IsNullOrWhiteSpace(maxExclusive))
{
throw new ArgumentNullException(nameof(maxExclusive));
}
return(StandByFeedContinuationToken.SerializeTokens(new CompositeContinuationToken[1] {
StandByFeedContinuationToken.CreateCompositeContinuationTokenForRange(minInclusive, maxExclusive, null)
}));
}
internal async Task <(string, ResponseMessage)> ReadNextInternalAsync(CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
if (this.compositeContinuationToken == null)
{
PartitionKeyRangeCache pkRangeCache = await this.clientContext.DocumentClient.GetPartitionKeyRangeCacheAsync();
this.containerRid = await this.container.GetRIDAsync(cancellationToken);
if (this.changeFeedStartFrom is ChangeFeedStartFromContinuation startFromContinuation)
{
this.compositeContinuationToken = await StandByFeedContinuationToken.CreateAsync(
this.containerRid,
startFromContinuation.Continuation,
pkRangeCache.TryGetOverlappingRangesAsync);
(CompositeContinuationToken token, string id) = await this.compositeContinuationToken.GetCurrentTokenAsync();
if (token.Token != null)
{
this.changeFeedStartFrom = ChangeFeedStartFrom.ContinuationToken(token.Token);
}
else
{
this.changeFeedStartFrom = ChangeFeedStartFrom.Beginning();
}
}
else
{
this.compositeContinuationToken = await StandByFeedContinuationToken.CreateAsync(
this.containerRid,
initialStandByFeedContinuationToken : null,
pkRangeCache.TryGetOverlappingRangesAsync);
}
}
(CompositeContinuationToken currentRangeToken, string rangeId) = await this.compositeContinuationToken.GetCurrentTokenAsync();
FeedRange feedRange = new FeedRangePartitionKeyRange(rangeId);
if (currentRangeToken.Token != null)
{
this.changeFeedStartFrom = new ChangeFeedStartFromContinuationAndFeedRange(currentRangeToken.Token, (FeedRangeInternal)feedRange);
}
else
{
this.changeFeedStartFrom = ChangeFeedStartFrom.Beginning(feedRange);
}
ResponseMessage response = await this.NextResultSetDelegateAsync(this.changeFeedOptions, cancellationToken);
if (await this.ShouldRetryFailureAsync(response, cancellationToken))
{
return(await this.ReadNextInternalAsync(cancellationToken));
}
if (response.IsSuccessStatusCode ||
response.StatusCode == HttpStatusCode.NotModified)
{
// Change Feed read uses Etag for continuation
currentRangeToken.Token = response.Headers.ETag;
}
return(rangeId, response);
}
