public CrossPartitionRangePageAsyncEnumerable(
IFeedRangeProvider feedRangeProvider,
CreatePartitionRangePageAsyncEnumerator <TPage, TState> createPartitionRangeEnumerator,
IComparer <PartitionRangePageAsyncEnumerator <TPage, TState> > comparer,
int maxConcurrency,
CrossFeedRangeState <TState> state = default)
{
this.feedRangeProvider = feedRangeProvider ?? throw new ArgumentNullException(nameof(comparer));
this.createPartitionRangeEnumerator = createPartitionRangeEnumerator ?? throw new ArgumentNullException(nameof(createPartitionRangeEnumerator));
this.comparer = comparer ?? throw new ArgumentNullException(nameof(comparer));
this.state = state;
this.maxConcurrency = maxConcurrency < 0 ? throw new ArgumentOutOfRangeException(nameof(maxConcurrency)) : maxConcurrency;
}
public CrossPartitionRangePageAsyncEnumerator(
IFeedRangeProvider feedRangeProvider,
CreatePartitionRangePageAsyncEnumerator <TPage, TState> createPartitionRangeEnumerator,
IComparer <PartitionRangePageAsyncEnumerator <TPage, TState> > comparer,
int?maxConcurrency,
PrefetchPolicy prefetchPolicy,
CancellationToken cancellationToken,
CrossFeedRangeState <TState> state = default)
{
this.feedRangeProvider = feedRangeProvider ?? throw new ArgumentNullException(nameof(feedRangeProvider));
this.createPartitionRangeEnumerator = createPartitionRangeEnumerator ?? throw new ArgumentNullException(nameof(createPartitionRangeEnumerator));
this.cancellationToken = cancellationToken;
this.lazyEnumerators = new AsyncLazy <IQueue <PartitionRangePageAsyncEnumerator <TPage, TState> > >((ITrace trace, CancellationToken token) =>
InitializeEnumeratorsAsync(
feedRangeProvider,
createPartitionRangeEnumerator,
comparer,
maxConcurrency,
prefetchPolicy,
state,
trace,
token));
}
public CrossPartitionRangePageAsyncEnumerator(
IFeedRangeProvider feedRangeProvider,
CreatePartitionRangePageAsyncEnumerator <TPage, TState> createPartitionRangeEnumerator,
IComparer <PartitionRangePageAsyncEnumerator <TPage, TState> > comparer,
int?maxConcurrency,
CancellationToken cancellationToken,
CrossFeedRangeState <TState> state = default)
{
this.feedRangeProvider = feedRangeProvider ?? throw new ArgumentNullException(nameof(feedRangeProvider));
this.createPartitionRangeEnumerator = createPartitionRangeEnumerator ?? throw new ArgumentNullException(nameof(createPartitionRangeEnumerator));
this.cancellationToken = cancellationToken;
this.lazyEnumerators = new AsyncLazy <IQueue <PartitionRangePageAsyncEnumerator <TPage, TState> > >(async(ITrace trace, CancellationToken token) =>
{
ReadOnlyMemory <FeedRangeState <TState> > rangeAndStates;
if (state != default)
{
rangeAndStates = state.Value;
}
else
{
// Fan out to all partitions with default state
List <FeedRangeEpk> ranges = await feedRangeProvider.GetFeedRangesAsync(trace, token);
List <FeedRangeState <TState> > rangesAndStatesBuilder = new List <FeedRangeState <TState> >(ranges.Count);
foreach (FeedRangeInternal range in ranges)
{
rangesAndStatesBuilder.Add(new FeedRangeState <TState>(range, default));
}
rangeAndStates = rangesAndStatesBuilder.ToArray();
}
List <BufferedPartitionRangePageAsyncEnumerator <TPage, TState> > bufferedEnumerators = new List <BufferedPartitionRangePageAsyncEnumerator <TPage, TState> >(rangeAndStates.Length);
for (int i = 0; i < rangeAndStates.Length; i++)
{
FeedRangeState <TState> feedRangeState = rangeAndStates.Span[i];
PartitionRangePageAsyncEnumerator <TPage, TState> enumerator = createPartitionRangeEnumerator(feedRangeState);
BufferedPartitionRangePageAsyncEnumerator <TPage, TState> bufferedEnumerator = new BufferedPartitionRangePageAsyncEnumerator <TPage, TState>(enumerator, cancellationToken);
bufferedEnumerators.Add(bufferedEnumerator);
}
if (maxConcurrency.HasValue)
{
await ParallelPrefetch.PrefetchInParallelAsync(bufferedEnumerators, maxConcurrency.Value, trace, token);
}
IQueue <PartitionRangePageAsyncEnumerator <TPage, TState> > queue;
if (comparer == null)
{
queue = new QueueWrapper <PartitionRangePageAsyncEnumerator <TPage, TState> >(
new Queue <PartitionRangePageAsyncEnumerator <TPage, TState> >(bufferedEnumerators));
}
else
{
queue = new PriorityQueueWrapper <PartitionRangePageAsyncEnumerator <TPage, TState> >(
new PriorityQueue <PartitionRangePageAsyncEnumerator <TPage, TState> >(
bufferedEnumerators,
comparer));
}
return(queue);
});
}
public async ValueTask <bool> MoveNextAsync(ITrace trace)
{
if (trace == null)
{
throw new ArgumentNullException(nameof(trace));
}
using (ITrace childTrace = trace.StartChild(name: nameof(MoveNextAsync), component: TraceComponent.Pagination, level: TraceLevel.Info))
{
IQueue <PartitionRangePageAsyncEnumerator <TPage, TState> > enumerators = await this.lazyEnumerators.GetValueAsync(
childTrace,
cancellationToken : this.cancellationToken);
if (enumerators.Count == 0)
{
this.Current = default;
this.CurrentRange = default;
this.nextState = default;
return(false);
}
PartitionRangePageAsyncEnumerator <TPage, TState> currentPaginator = enumerators.Dequeue();
currentPaginator.SetCancellationToken(this.cancellationToken);
bool moveNextResult = false;
try
{
moveNextResult = await currentPaginator.MoveNextAsync(childTrace);
}
catch
{
// Re-queue the enumerator to avoid emptying the queue
enumerators.Enqueue(currentPaginator);
throw;
}
if (!moveNextResult)
{
// Current enumerator is empty,
// so recursively retry on the next enumerator.
return(await this.MoveNextAsync(childTrace));
}
if (currentPaginator.Current.Failed)
{
// Check if it's a retryable exception.
Exception exception = currentPaginator.Current.Exception;
while (exception.InnerException != null)
{
exception = exception.InnerException;
}
if (IsSplitException(exception))
{
// Handle split
List <FeedRangeEpk> childRanges = await this.feedRangeProvider.GetChildRangeAsync(
currentPaginator.FeedRangeState.FeedRange,
childTrace,
this.cancellationToken);
if (childRanges.Count <= 1)
{
// We optimistically assumed that the cache is not stale.
// In the event that it is (where we only get back one child / the partition that we think got split)
// Then we need to refresh the cache
await this.feedRangeProvider.RefreshProviderAsync(childTrace, this.cancellationToken);
childRanges = await this.feedRangeProvider.GetChildRangeAsync(
currentPaginator.FeedRangeState.FeedRange,
childTrace,
this.cancellationToken);
}
if (childRanges.Count < 1)
{
string errorMessage = "SDK invariant violated 4795CC37: Must have at least one EPK range in a cross partition enumerator";
throw Resource.CosmosExceptions.CosmosExceptionFactory.CreateInternalServerErrorException(
message: errorMessage,
headers: null,
stackTrace: null,
trace: childTrace,
error: new Microsoft.Azure.Documents.Error {
Code = "SDK_invariant_violated_4795CC37", Message = errorMessage
});
}
if (childRanges.Count == 1)
{
// On a merge, the 410/1002 results in a single parent
// We maintain the current enumerator's range and let the RequestInvokerHandler logic kick in
enumerators.Enqueue(currentPaginator);
}
else
{
// Split
foreach (FeedRangeInternal childRange in childRanges)
{
PartitionRangePageAsyncEnumerator <TPage, TState> childPaginator = this.createPartitionRangeEnumerator(
new FeedRangeState <TState>(childRange, currentPaginator.FeedRangeState.State));
enumerators.Enqueue(childPaginator);
}
}
// Recursively retry
return(await this.MoveNextAsync(childTrace));
}
// Just enqueue the paginator and the user can decide if they want to retry.
enumerators.Enqueue(currentPaginator);
this.Current = TryCatch <CrossFeedRangePage <TPage, TState> > .FromException(currentPaginator.Current.Exception);
this.CurrentRange = currentPaginator.FeedRangeState.FeedRange;
this.nextState = CrossPartitionRangePageAsyncEnumerator <TPage, TState> .GetNextRange(enumerators);
return(true);
}
if (currentPaginator.FeedRangeState.State != default)
{
// Don't enqueue the paginator otherwise it's an infinite loop.
enumerators.Enqueue(currentPaginator);
}
CrossFeedRangeState <TState> crossPartitionState;
if (enumerators.Count == 0)
{
crossPartitionState = null;
}
else
{
FeedRangeState <TState>[] feedRangeAndStates = new FeedRangeState <TState> [enumerators.Count];
int i = 0;
foreach (PartitionRangePageAsyncEnumerator <TPage, TState> enumerator in enumerators)
{
feedRangeAndStates[i++] = enumerator.FeedRangeState;
}
crossPartitionState = new CrossFeedRangeState <TState>(feedRangeAndStates);
}
this.Current = TryCatch <CrossFeedRangePage <TPage, TState> > .FromResult(
new CrossFeedRangePage <TPage, TState>(currentPaginator.Current.Result, crossPartitionState));
this.CurrentRange = currentPaginator.FeedRangeState.FeedRange;
this.nextState = CrossPartitionRangePageAsyncEnumerator <TPage, TState> .GetNextRange(enumerators);
return(true);
}
}
public CrossFeedRangePage(TBackendPage backendEndPage, CrossFeedRangeState <TBackendState> state)
: base(backendEndPage.RequestCharge, backendEndPage.ActivityId, backendEndPage.AdditionalHeaders, state)
{
this.Page = backendEndPage;
}
public async ValueTask <bool> MoveNextAsync(ITrace trace)
{
if (trace == null)
{
throw new ArgumentNullException(nameof(trace));
}
this.cancellationToken.ThrowIfCancellationRequested();
using (ITrace childTrace = trace.StartChild(name: nameof(MoveNextAsync), component: TraceComponent.Pagination, level: TraceLevel.Info))
{
IQueue <PartitionRangePageAsyncEnumerator <TPage, TState> > enumerators = await this.lazyEnumerators.GetValueAsync(
childTrace,
cancellationToken : this.cancellationToken);
if (enumerators.Count == 0)
{
this.Current = default;
this.CurrentRange = default;
return(false);
}
PartitionRangePageAsyncEnumerator <TPage, TState> currentPaginator = enumerators.Dequeue();
if (!await currentPaginator.MoveNextAsync(childTrace))
{
// Current enumerator is empty,
// so recursively retry on the next enumerator.
return(await this.MoveNextAsync(childTrace));
}
if (currentPaginator.Current.Failed)
{
// Check if it's a retryable exception.
Exception exception = currentPaginator.Current.Exception;
while (exception.InnerException != null)
{
exception = exception.InnerException;
}
if (IsSplitException(exception))
{
// Handle split
List <FeedRangeEpk> childRanges = await this.feedRangeProvider.GetChildRangeAsync(
currentPaginator.FeedRangeState.FeedRange,
childTrace,
this.cancellationToken);
if (childRanges.Count == 0)
{
throw new InvalidOperationException("Got back no children");
}
if (childRanges.Count == 1)
{
// We optimistically assumed that the cache is not stale.
// In the event that it is (where we only get back one child / the partition that we think got split)
// Then we need to refresh the cache
await this.feedRangeProvider.RefreshProviderAsync(childTrace, this.cancellationToken);
childRanges = await this.feedRangeProvider.GetChildRangeAsync(
currentPaginator.FeedRangeState.FeedRange,
childTrace,
this.cancellationToken);
}
if (childRanges.Count() <= 1)
{
throw new InvalidOperationException("Expected more than 1 child");
}
foreach (FeedRangeInternal childRange in childRanges)
{
PartitionRangePageAsyncEnumerator <TPage, TState> childPaginator = this.createPartitionRangeEnumerator(
new FeedRangeState <TState>(childRange, currentPaginator.FeedRangeState.State));
enumerators.Enqueue(childPaginator);
}
// Recursively retry
return(await this.MoveNextAsync(childTrace));
}
// Just enqueue the paginator and the user can decide if they want to retry.
enumerators.Enqueue(currentPaginator);
this.Current = TryCatch <CrossFeedRangePage <TPage, TState> > .FromException(currentPaginator.Current.Exception);
this.CurrentRange = currentPaginator.FeedRangeState.FeedRange;
return(true);
}
if (currentPaginator.FeedRangeState.State != default)
{
// Don't enqueue the paginator otherwise it's an infinite loop.
enumerators.Enqueue(currentPaginator);
}
CrossFeedRangeState <TState> crossPartitionState;
if (enumerators.Count == 0)
{
crossPartitionState = null;
}
else
{
FeedRangeState <TState>[] feedRangeAndStates = new FeedRangeState <TState> [enumerators.Count];
int i = 0;
foreach (PartitionRangePageAsyncEnumerator <TPage, TState> enumerator in enumerators)
{
feedRangeAndStates[i++] = enumerator.FeedRangeState;
}
crossPartitionState = new CrossFeedRangeState <TState>(feedRangeAndStates);
}
this.Current = TryCatch <CrossFeedRangePage <TPage, TState> > .FromResult(
new CrossFeedRangePage <TPage, TState>(currentPaginator.Current.Result, crossPartitionState));
this.CurrentRange = currentPaginator.FeedRangeState.FeedRange;
return(true);
}
}
public async ValueTask <bool> MoveNextAsync()
{
this.cancellationToken.ThrowIfCancellationRequested();
IQueue <PartitionRangePageAsyncEnumerator <TPage, TState> > enumerators = await this.lazyEnumerators.GetValueAsync(cancellationToken : this.cancellationToken);
if (enumerators.Count == 0)
{
this.Current = default;
this.CurrentRange = default;
return(false);
}
PartitionRangePageAsyncEnumerator <TPage, TState> currentPaginator = enumerators.Dequeue();
if (!await currentPaginator.MoveNextAsync())
{
// Current enumerator is empty,
// so recursively retry on the next enumerator.
return(await this.MoveNextAsync());
}
if (currentPaginator.Current.Failed)
{
// Check if it's a retryable exception.
Exception exception = currentPaginator.Current.Exception;
while (exception.InnerException != null)
{
exception = exception.InnerException;
}
if (IsSplitException(exception))
{
// Handle split
IEnumerable <FeedRangeInternal> childRanges = await this.feedRangeProvider.GetChildRangeAsync(
currentPaginator.Range,
cancellationToken : this.cancellationToken);
foreach (FeedRangeInternal childRange in childRanges)
{
PartitionRangePageAsyncEnumerator <TPage, TState> childPaginator = this.createPartitionRangeEnumerator(
childRange,
currentPaginator.State);
enumerators.Enqueue(childPaginator);
}
// Recursively retry
return(await this.MoveNextAsync());
}
if (IsMergeException(exception))
{
throw new NotImplementedException();
}
// Just enqueue the paginator and the user can decide if they want to retry.
enumerators.Enqueue(currentPaginator);
this.Current = TryCatch <CrossFeedRangePage <TPage, TState> > .FromException(currentPaginator.Current.Exception);
this.CurrentRange = currentPaginator.Range;
return(true);
}
if (currentPaginator.State != default)
{
// Don't enqueue the paginator otherwise it's an infinite loop.
enumerators.Enqueue(currentPaginator);
}
CrossFeedRangeState <TState> crossPartitionState;
if (enumerators.Count == 0)
{
crossPartitionState = null;
}
else
{
FeedRangeState <TState>[] feedRangeAndStates = new FeedRangeState <TState> [enumerators.Count];
int i = 0;
foreach (PartitionRangePageAsyncEnumerator <TPage, TState> enumerator in enumerators)
{
feedRangeAndStates[i++] = new FeedRangeState <TState>(enumerator.Range, enumerator.State);
}
crossPartitionState = new CrossFeedRangeState <TState>(feedRangeAndStates);
}
this.Current = TryCatch <CrossFeedRangePage <TPage, TState> > .FromResult(
new CrossFeedRangePage <TPage, TState>(currentPaginator.Current.Result, crossPartitionState));
this.CurrentRange = currentPaginator.Range;
return(true);
}