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CSHARP-1715: Added support for $facet aggregation stage.
1 parent b07f674 commit 4e06ffa

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+1156
-25
lines changed

‎src/MongoDB.Driver.Core/Core/Misc/Feature.cs‎

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@@ -29,6 +29,7 @@ public class Feature
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private static readonly Feature __aggregateCountStage = new Feature("AggregateCountStage", new SemanticVersion(3, 3, 11));
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private static readonly Feature __aggregateCursorResult = new Feature("AggregateCursorResult", new SemanticVersion(2, 6, 0));
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private static readonly Feature __aggregateExplain = new Feature("AggregateExplain", new SemanticVersion(2, 6, 0));
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private static readonly Feature __aggregateFacetStage = new Feature("AggregateFacetStage", new SemanticVersion(3, 4, 0, "rc0"));
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private static readonly Feature __aggregateOut = new Feature("Aggregate", new SemanticVersion(2, 6, 0));
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private static readonly Feature __bypassDocumentValidation = new Feature("BypassDocumentValidation", new SemanticVersion(3, 2, 0));
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private static readonly CollationFeature __collation = new CollationFeature("Collation", new SemanticVersion(3, 3, 11));
@@ -82,6 +83,11 @@ public class Feature
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/// </summary>
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public static Feature AggregateExplain => __aggregateExplain;
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/// <summary>
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/// Gets the aggregate $facet stage feature.
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/// </summary>
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public static Feature AggregateFacetStage => __aggregateFacetStage;
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/// <summary>
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/// Gets the aggregate out feature.
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/// </summary>

‎src/MongoDB.Driver/AggregateFacet.cs‎

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/* Copyright 2016 MongoDB Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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using System;
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using MongoDB.Bson;
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using MongoDB.Bson.Serialization;
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using MongoDB.Driver.Core.Misc;
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namespace MongoDB.Driver
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{
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/// <summary>
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/// Represents static methods for creating facets.
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/// </summary>
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public static class AggregateFacet
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{
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/// <summary>
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/// Creates a new instance of the <see cref="AggregateFacet{TInput, TOutput}" /> class.
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/// </summary>
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/// <typeparam name="TInput">The type of the input documents.</typeparam>
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/// <typeparam name="TOutput">The type of the output documents.</typeparam>
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/// <param name="name">The facet name.</param>
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/// <param name="pipeline">The facet pipeline.</param>
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/// <returns>
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/// A new instance of the <see cref="AggregateFacet{TInput, TOutput}" /> class
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/// </returns>
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public static AggregateFacet<TInput, TOutput> Create<TInput, TOutput>(string name, PipelineDefinition<TInput, TOutput> pipeline)
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{
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return new AggregateFacet<TInput, TOutput>(name, pipeline);
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}
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}
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/// <summary>
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/// Represents a facet to be passed to the Facet method.
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/// </summary>
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/// <typeparam name="TInput">The type of the input documents.</typeparam>
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public abstract class AggregateFacet<TInput>
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{
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/// <summary>
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/// Initializes a new instance of the <see cref="AggregateFacet{TInput}"/> class.
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/// </summary>
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/// <param name="name">The facet name.</param>
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protected AggregateFacet(string name)
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{
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Name = Ensure.IsNotNull(name, nameof(name));
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}
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/// <summary>
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/// Gets the facet name.
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/// </summary>
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public string Name { get; private set; }
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/// <summary>
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/// Gets the output serializer.
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/// </summary>
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public abstract IBsonSerializer OutputSerializer { get; }
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/// <summary>
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/// Gets the type of the output documents.
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/// </summary>
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public abstract Type OutputType { get; }
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/// <summary>
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/// Renders the facet pipeline.
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/// </summary>
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/// <param name="inputSerializer">The input serializer.</param>
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/// <param name="serializerRegistry">The serializer registry.</param>
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/// <returns>The rendered pipeline.</returns>
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public abstract BsonArray RenderPipeline(IBsonSerializer<TInput> inputSerializer, IBsonSerializerRegistry serializerRegistry);
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}
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/// <summary>
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/// Represents a facet to be passed to the Facet method.
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/// </summary>
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/// <typeparam name="TInput">The type of the input documents.</typeparam>
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/// <typeparam name="TOutput">The type of the otuput documents.</typeparam>
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public class AggregateFacet<TInput, TOutput> : AggregateFacet<TInput>
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{
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/// <summary>
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/// Initializes a new instance of the <see cref="AggregateFacet{TInput, TOutput}"/> class.
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/// </summary>
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/// <param name="name">The facet name.</param>
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/// <param name="pipeline">The facet pipeline.</param>
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public AggregateFacet(string name, PipelineDefinition<TInput, TOutput> pipeline)
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: base(name)
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{
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Pipeline = Ensure.IsNotNull(pipeline, nameof(pipeline));
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}
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/// <inheritdoc/>
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public override IBsonSerializer OutputSerializer => Pipeline.OutputSerializer;
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/// <inheritdoc/>
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public override Type OutputType => typeof(TOutput);
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/// <summary>
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/// Gets the facet pipeline.
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/// </summary>
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public PipelineDefinition<TInput, TOutput> Pipeline { get; private set; }
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/// <inheritdoc/>
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public override BsonArray RenderPipeline(IBsonSerializer<TInput> inputSerializer, IBsonSerializerRegistry serializerRegistry)
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{
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var renderedPipeline = Pipeline.Render(inputSerializer, serializerRegistry);
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return new BsonArray(renderedPipeline.Documents);
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}
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}
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}

‎src/MongoDB.Driver/AggregateFacetOptions.cs‎

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/* Copyright 2016 MongoDB Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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using MongoDB.Bson.Serialization;
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namespace MongoDB.Driver
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{
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/// <summary>
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/// Options for the aggregate $facet stage.
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/// </summary>
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/// <typeparam name="TNewResult">The type of the new result.</typeparam>
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public sealed class AggregateFacetOptions<TNewResult>
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{
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private IBsonSerializer<TNewResult> _newResultSerializer;
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/// <summary>
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/// Gets or sets the new result serializer.
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/// </summary>
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public IBsonSerializer<TNewResult> NewResultSerializer
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{
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get { return _newResultSerializer; }
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set { _newResultSerializer = value; }
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}
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}
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}

‎src/MongoDB.Driver/AggregateFacetResult.cs‎

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1+
/* Copyright 2016 MongoDB Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
5+
* You may obtain a copy of the License at
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*
7+
* http://www.apache.org/licenses/LICENSE-2.0
8+
*
9+
* Unless required by applicable law or agreed to in writing, software
10+
* distributed under the License is distributed on an "AS IS" BASIS,
11+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12+
* See the License for the specific language governing permissions and
13+
* limitations under the License.
14+
*/
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16+
using System.Collections.Generic;
17+
using System.Linq;
18+
using MongoDB.Driver.Core.Misc;
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20+
namespace MongoDB.Driver
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{
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/// <summary>
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/// Represents an abstract AggregateFacetResult with an arbitrary TOutput type.
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/// </summary>
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public abstract class AggregateFacetResult
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{
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/// <summary>
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/// Initializes a new instance of the <see cref="AggregateFacetResult" /> class.
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/// </summary>
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/// <param name="name">The name of the facet.</param>
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internal AggregateFacetResult(string name)
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{
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Name = Ensure.IsNotNull(name, nameof(name));
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}
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/// <summary>
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/// Gets the name of the facet.
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/// </summary>
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public string Name { get; private set; }
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/// <summary>
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/// Gets the output of the facet.
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/// </summary>
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public IReadOnlyList<TOutput> Output<TOutput>()
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{
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return ((AggregateFacetResult<TOutput>)this).Output;
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}
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}
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/// <summary>
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/// Represents the result of a single facet.
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/// </summary>
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/// <typeparam name="TOutput">The type of the output.</typeparam>
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public sealed class AggregateFacetResult<TOutput> : AggregateFacetResult
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{
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/// <summary>
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/// Initializes a new instance of the <see cref="AggregateFacetResult{TOutput}"/> class.
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/// </summary>
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/// <param name="name">The name.</param>
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/// <param name="output">The output.</param>
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public AggregateFacetResult(string name, IEnumerable<TOutput> output)
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: base(name)
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{
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Ensure.IsNotNull(output, nameof(output));
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var readOnlyList = output as IReadOnlyList<TOutput>;
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if (readOnlyList != null)
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{
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Output = readOnlyList;
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}
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else
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{
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Output = output.ToArray();
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}
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}
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/// <summary>
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/// Gets or sets the output.
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/// </summary>
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/// <value>
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/// The output.
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/// </value>
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public IReadOnlyList<TOutput> Output { get; set; }
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}
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}

‎src/MongoDB.Driver/AggregateFacetResults.cs‎

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/* Copyright 2016 MongoDB Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
11+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12+
* See the License for the specific language governing permissions and
13+
* limitations under the License.
14+
*/
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16+
using System;
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using System.Collections.Generic;
18+
using System.Linq;
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using System.Reflection;
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using MongoDB.Bson;
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using MongoDB.Bson.IO;
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using MongoDB.Bson.Serialization;
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using MongoDB.Bson.Serialization.Serializers;
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using MongoDB.Driver.Core.Misc;
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namespace MongoDB.Driver
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{
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/// <summary>
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/// Represents the results of a $facet stage with an arbitrary number of facets.
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/// </summary>
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public class AggregateFacetResults
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{
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/// <summary>
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/// Initializes a new instance of the <see cref="AggregateFacetResults"/> class.
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/// </summary>
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/// <param name="facets">The facets.</param>
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public AggregateFacetResults(AggregateFacetResult[] facets)
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{
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Facets = Ensure.IsNotNull(facets, nameof(facets));
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}
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/// <summary>
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/// Gets the facets.
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/// </summary>
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public IReadOnlyList<AggregateFacetResult> Facets { get; private set; }
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}
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internal class AggregateFacetResultsSerializer : SerializerBase<AggregateFacetResults>
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{
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private readonly string[] _names;
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private readonly IBsonSerializer[] _serializers;
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public AggregateFacetResultsSerializer(IEnumerable<string> names, IEnumerable<IBsonSerializer> serializers)
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{
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_names = names.ToArray();
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_serializers = serializers.ToArray();
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}
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public override AggregateFacetResults Deserialize(BsonDeserializationContext context, BsonDeserializationArgs args)
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{
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var facets = new AggregateFacetResult[_names.Length];
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var reader = context.Reader;
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reader.ReadStartDocument();
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while (reader.ReadBsonType() != 0)
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{
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var name = reader.ReadName();
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var index = Array.IndexOf(_names, name);
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if (index != -1)
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{
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var itemSerializer = _serializers[index];
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var itemType = itemSerializer.ValueType;
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var itemSerializerType = typeof(IBsonSerializer<>).MakeGenericType(itemType);
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var arraySerializerType = typeof(ArraySerializer<>).MakeGenericType(itemType);
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var arraySerializerConstructor = arraySerializerType.GetTypeInfo().GetConstructor(new[] { itemSerializerType });
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var arraySerializer = (IBsonSerializer)arraySerializerConstructor.Invoke(new object[] { itemSerializer });
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var output = (Array)arraySerializer.Deserialize(context);
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var facetType = typeof(AggregateFacetResult<>).MakeGenericType(itemType);
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var ienumerableItemType = typeof(IEnumerable<>).MakeGenericType(itemType);
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var facetConstructor = facetType.GetTypeInfo().GetConstructor(new[] { typeof(string), ienumerableItemType });
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var facet = (AggregateFacetResult)facetConstructor.Invoke(new object[] { name, output });
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facets[index] = facet;
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}
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else
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{
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throw new BsonSerializationException($"Unexpected field name '{name}' in $facet result.");
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}
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}
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reader.ReadEndDocument();
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var missingIndex = Array.IndexOf(facets, null);
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if (missingIndex != -1)
93+
{
94+
var missingName = _names[missingIndex];
95+
throw new BsonSerializationException($"Field name '{missingName}' in $facet result.");
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}
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return new AggregateFacetResults(facets);
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}
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}
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}

‎src/MongoDB.Driver/AggregateFluent.cs‎

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@@ -231,6 +231,30 @@ public override IAggregateFluent<AggregateCountResult> Count()
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return AppendStage<AggregateCountResult>(stage);
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}
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public override IAggregateFluent<TNewResult> Facet<TNewResult>(
235+
IEnumerable<AggregateFacet<TResult>> facets,
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AggregateFacetOptions<TNewResult> options = null)
237+
{
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const string operatorName = "$facet";
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var materializedFacets = facets.ToArray();
240+
var stage = new DelegatedPipelineStageDefinition<TResult, TNewResult>(
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operatorName,
242+
(s, sr) =>
243+
{
244+
var facetsDocument = new BsonDocument();
245+
foreach (var facet in materializedFacets)
246+
{
247+
var renderedPipeline = facet.RenderPipeline(s, sr);
248+
facetsDocument.Add(facet.Name, renderedPipeline);
249+
}
250+
var document = new BsonDocument("$facet", facetsDocument);
251+
var resultSerializer = options?.NewResultSerializer ?? sr.GetSerializer<TNewResult>();
252+
return new RenderedPipelineStageDefinition<TNewResult>(operatorName, document, resultSerializer);
253+
});
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255+
return AppendStage<TNewResult>(stage);
256+
}
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public override IAggregateFluent<TNewResult> Group<TNewResult>(ProjectionDefinition<TResult, TNewResult> group)
235259
{
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const string operatorName = "$group";

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