public static async Task <TryCatch <IDocumentQueryExecutionComponent> > TryCreateAsync(
CosmosQueryContext queryContext,
CosmosCrossPartitionQueryExecutionContext.CrossPartitionInitParams initParams,
CosmosElement requestContinuationToken,
CancellationToken cancellationToken)
{
Debug.Assert(
initParams.PartitionedQueryExecutionInfo.QueryInfo.HasOrderBy,
"OrderBy~Context must have order by query info.");
if (queryContext == null)
{
throw new ArgumentNullException(nameof(queryContext));
}
cancellationToken.ThrowIfCancellationRequested();
// TODO (brchon): For now we are not honoring non deterministic ORDER BY queries, since there is a bug in the continuation logic.
// We can turn it back on once the bug is fixed.
// This shouldn't hurt any query results.
OrderByItemProducerTreeComparer orderByItemProducerTreeComparer = new OrderByItemProducerTreeComparer(initParams.PartitionedQueryExecutionInfo.QueryInfo.OrderBy.ToArray());
CosmosOrderByItemQueryExecutionContext context = new CosmosOrderByItemQueryExecutionContext(
initPararms: queryContext,
maxConcurrency: initParams.MaxConcurrency,
maxItemCount: initParams.MaxItemCount,
maxBufferedItemCount: initParams.MaxBufferedItemCount,
consumeComparer: orderByItemProducerTreeComparer,
testSettings: initParams.TestSettings);
IReadOnlyList <string> orderByExpressions = initParams.PartitionedQueryExecutionInfo.QueryInfo.OrderByExpressions;
IReadOnlyList <SortOrder> sortOrders = initParams.PartitionedQueryExecutionInfo.QueryInfo.OrderBy;
if (orderByExpressions.Count != sortOrders.Count)
{
throw new ArgumentException("order by expressions count does not match sort order");
}
IReadOnlyList <OrderByColumn> columns = orderByExpressions
.Zip(sortOrders, (expression, order) => new OrderByColumn(expression, order))
.ToList();
return((await context.TryInitializeAsync(
sqlQuerySpec: initParams.SqlQuerySpec,
requestContinuation: requestContinuationToken,
collectionRid: initParams.CollectionRid,
partitionKeyRanges: initParams.PartitionKeyRanges,
initialPageSize: initParams.InitialPageSize,
orderByColumns: columns,
cancellationToken: cancellationToken))
.Try <IDocumentQueryExecutionComponent>(() => context));
}
/// <summary>
/// Initializes a new instance of the CosmosOrderByItemQueryExecutionContext class.
/// </summary>
/// <param name="initPararms">The params used to construct the base class.</param>
/// For cross partition order by queries a query like "SELECT c.id, c.field_0 ORDER BY r.field_7 gets rewritten as:
/// <![CDATA[
/// SELECT r._rid, [{"item": r.field_7}] AS orderByItems, {"id": r.id, "field_0": r.field_0} AS payload
/// FROM r
/// WHERE({ document db - formattable order by query - filter})
/// ORDER BY r.field_7]]>
/// This is needed because we need to add additional filters to the query when we resume from a continuation,
/// and it lets us easily parse out the _rid orderByItems, and payload without parsing the entire document (and having to remember the order by field).
/// <param name="maxConcurrency">The max concurrency</param>
/// <param name="maxBufferedItemCount">The max buffered item count</param>
/// <param name="maxItemCount">Max item count</param>
/// <param name="consumeComparer">Comparer used to internally compare documents from different sorted partitions.</param>
/// <param name="testSettings">Test settings.</param>
private CosmosOrderByItemQueryExecutionContext(
CosmosQueryContext initPararms,
int?maxConcurrency,
int?maxItemCount,
int?maxBufferedItemCount,
OrderByItemProducerTreeComparer consumeComparer,
TestInjections testSettings)
: base(
queryContext: initPararms,
maxConcurrency: maxConcurrency,
maxItemCount: maxItemCount,
maxBufferedItemCount: maxBufferedItemCount,
moveNextComparer: consumeComparer,
fetchPrioirtyFunction: CosmosOrderByItemQueryExecutionContext.FetchPriorityFunction,
equalityComparer: new OrderByEqualityComparer(consumeComparer),
returnResultsInDeterministicOrder: true,
testSettings: testSettings)
{
}