Add max_children to Nested Sort (#4596)

russcam · russcam · commit 48919091c00d · 2020-04-17T16:26:21.000+10:00
This commit adds max_children to nested sort. Closes #4595 (cherry picked from commit 7aa05d9)
diff --git a/docs/search/request/sort-usage.asciidoc b/docs/search/request/sort-usage.asciidoc
@@ -35,8 +35,10 @@ s => s
         .MissingLast()
         .UnmappedType(FieldType.Date)
         .Mode(SortMode.Average)
-        .NestedPath(p => p.Tags)
-        .NestedFilter(q => q.MatchAll())
+        .Nested(n => n
+            .Path(p => p.Tags)
+            .Filter(q => q.MatchAll())
+        )
     )
     .Field(f => f
         .Field(p => p.NumberOfCommits)
@@ -51,6 +53,10 @@ s => s
         .Mode(SortMode.Min)
         .Points(new GeoLocation(70, -70), new GeoLocation(-12, 12))
     )
+    .GeoDistance(g => g
+        .Field(p => p.LocationPoint)
+        .Points(new GeoLocation(70, -70), new GeoLocation(-12, 12))
+    )
     .Script(sc => sc
         .Type("number")
         .Ascending()
@@ -82,8 +88,11 @@ new SearchRequest<Project>
             Missing = "_last",
             UnmappedType = FieldType.Date,
             Mode = SortMode.Average,
-            NestedPath = Field<Project>(p => p.Tags),
-            NestedFilter = new MatchAllQuery(),
+            Nested = new NestedSort
+            {
+                Path = Field<Project>(p => p.Tags),
+                Filter = new MatchAllQuery()
+            }
         },
         new SortField
         {
@@ -100,6 +109,11 @@ new SearchRequest<Project>
             Mode = SortMode.Min,
             Points = new[] { new GeoLocation(70, -70), new GeoLocation(-12, 12) }
         },
+        new GeoDistanceSort
+        {
+            Field = "locationPoint",
+            Points = new[] { new GeoLocation(70, -70), new GeoLocation(-12, 12) }
+        },
         new ScriptSort
         {
             Type = "number",
@@ -146,9 +160,11 @@ new SearchRequest<Project>
         "missing": "_last",
         "order": "desc",
         "mode": "avg",
-        "nested_path": "tags",
-        "nested_filter": {
-          "match_all": {}
+        "nested": {
+          "path": "tags",
+          "filter": {
+            "match_all": {}
+          }
         },
         "unmapped_type": "date"
       }
@@ -177,6 +193,20 @@ new SearchRequest<Project>
         "unit": "cm"
       }
     },
+    {
+      "_geo_distance": {
+        "locationPoint": [
+          {
+            "lat": 70.0,
+            "lon": -70.0
+          },
+          {
+            "lat": -12.0,
+            "lon": 12.0
+          }
+        ]
+      }
+    },
     {
       "_script": {
         "order": "asc",
@@ -214,6 +244,7 @@ s => s
             .Filter(ff => ff
                 .MatchAll()
             )
+            .MaxChildren(50)
         )
     )
 )
@@ -238,7 +269,8 @@ new SearchRequest<Project>
             Nested = new NestedSort
             {
                 Path = Field<Project>(p => p.Tags),
-                Filter = new MatchAllQuery()
+                Filter = new MatchAllQuery(),
+                MaxChildren = 50
             }
         }
     }
@@ -259,7 +291,8 @@ new SearchRequest<Project>
           "path": "tags",
           "filter": {
             "match_all": {}
-          }
+          },
+          "max_children": 50
         },
         "unmapped_type": "date"
       }
diff --git a/src/Nest/Search/Search/Sort/NestedSort.cs b/src/Nest/Search/Search/Sort/NestedSort.cs
@@ -4,42 +4,80 @@
 
 namespace Nest
 {
+	/// <summary>
+	/// Sort on a field inside one or more nested objects.
+	/// </summary>
 	[JsonObject(MemberSerialization = MemberSerialization.OptIn)]
 	[JsonConverter(typeof(ReadAsTypeJsonConverter<NestedSort>))]
 	public interface INestedSort
 	{
+		/// <summary>
+		/// A filter that the inner objects inside the nested path should match with in order for its field values to be taken into account
+		/// by sorting. A common pattern is to repeat the query/filter inside the nested filter or query.
+		/// By default no nested filter is active.
+		/// </summary>
 		[JsonProperty("filter")]
 		QueryContainer Filter { get; set; }
 
+		/// <summary>
+		/// Same as top-level nested, but applies to another nested path within the current nested object.
+		/// </summary>
 		[JsonProperty("nested")]
 		INestedSort Nested { get; set; }
 
+		/// <summary>
+		/// Defines on which nested object to sort. The actual sort field must be a direct field inside this nested object.
+		/// When sorting by nested field, this field is mandatory.
+		/// </summary>
 		[JsonProperty("path")]
 		Field Path { get; set; }
+
+		/// <summary>
+		/// The maximum number of children to consider per root document when picking the sort value. Defaults to unlimited.
+		/// <para />
+		/// Available in Elasticsearch 6.5.0+
+		/// </summary>
+		[JsonProperty("max_children")]
+		int? MaxChildren { get; set; }
 	}
 
+	/// <inheritdoc />
 	public class NestedSort : INestedSort
 	{
+		/// <inheritdoc />
 		public QueryContainer Filter { get; set; }
+		/// <inheritdoc />
 		public INestedSort Nested { get; set; }
+		/// <inheritdoc />
 		public Field Path { get; set; }
+		/// <inheritdoc />
+		public int? MaxChildren { get; set; }
 	}
 
+	/// <inheritdoc cref="INestedSort"/>
 	public class NestedSortDescriptor<T>
 		: DescriptorBase<NestedSortDescriptor<T>, INestedSort>, INestedSort where T : class
 	{
 		QueryContainer INestedSort.Filter { get; set; }
 		INestedSort INestedSort.Nested { get; set; }
 		Field INestedSort.Path { get; set; }
+		int? INestedSort.MaxChildren { get; set; }
 
+		/// <inheritdoc cref="INestedSort.Path"/>
 		public NestedSortDescriptor<T> Path(Field path) => Assign(path, (a, v) => a.Path = v);
 
+		/// <inheritdoc cref="INestedSort.Path"/>
 		public NestedSortDescriptor<T> Path(Expression<Func<T, object>> objectPath) => Assign(objectPath, (a, v) => a.Path = v);
 
+		/// <inheritdoc cref="INestedSort.Filter"/>
 		public NestedSortDescriptor<T> Filter(Func<QueryContainerDescriptor<T>, QueryContainer> filterSelector) =>
 			Assign(filterSelector, (a, v) => a.Filter = v?.Invoke(new QueryContainerDescriptor<T>()));
 
+		/// <inheritdoc cref="INestedSort.Nested"/>
 		public NestedSortDescriptor<T> Nested(Func<NestedSortDescriptor<T>, INestedSort> filterSelector) =>
 			Assign(filterSelector, (a, v) => a.Nested = v?.Invoke(new NestedSortDescriptor<T>()));
+
+		/// <inheritdoc cref="INestedSort.MaxChildren"/>
+		public NestedSortDescriptor<T> MaxChildren(int? maxChildren) => Assign(maxChildren, (a, v) => a.MaxChildren = v);
 	}
 }
diff --git a/src/Tests/Tests/Search/Request/SortUsageTests.cs b/src/Tests/Tests/Search/Request/SortUsageTests.cs
@@ -35,10 +35,13 @@ public SortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(clust
 								missing = "_last",
 								order = "desc",
 								mode = "avg",
-								nested_path = "tags",
-								nested_filter = new
+								nested = new
 								{
-									match_all = new { }
+									path = "tags",
+									filter = new
+									{
+										match_all = new { }
+									}
 								},
 								unmapped_type = "date"
 							}
@@ -76,6 +79,25 @@ public SortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(clust
 						}
 					},
 					new
+					{
+						_geo_distance = new
+						{
+							locationPoint = new[]
+							{
+								new
+								{
+									lat = 70.0,
+									lon = -70.0
+								},
+								new
+								{
+									lat = -12.0,
+									lon = 12.0
+								}
+							}
+						}
+					},
+					new
 					{
 						_script = new
 						{
@@ -106,8 +128,10 @@ public SortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(clust
 					.MissingLast()
 					.UnmappedType(FieldType.Date)
 					.Mode(SortMode.Average)
-					.NestedPath(p => p.Tags)
-					.NestedFilter(q => q.MatchAll())
+					.Nested(n => n
+						.Path(p => p.Tags)
+						.Filter(q => q.MatchAll())
+					)
 				)
 				.Field(f => f
 					.Field(p => p.NumberOfCommits)
@@ -122,6 +146,10 @@ public SortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(clust
 					.Mode(SortMode.Min)
 					.Points(new GeoLocation(70, -70), new GeoLocation(-12, 12))
 				)
+				.GeoDistance(g => g
+					.Field(p => p.LocationPoint)
+					.Points(new GeoLocation(70, -70), new GeoLocation(-12, 12))
+				)
 				.Script(sc => sc
 					.Type("number")
 					.Ascending()
@@ -149,10 +177,11 @@ public SortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(clust
 						Missing = "_last",
 						UnmappedType = FieldType.Date,
 						Mode = SortMode.Average,
-#pragma warning disable 618
-						NestedPath = Field<Project>(p => p.Tags),
-						NestedFilter = new MatchAllQuery(),
-#pragma warning restore 618
+						Nested = new NestedSort
+						{
+							Path = Field<Project>(p => p.Tags),
+							Filter = new MatchAllQuery()
+						}
 					},
 					new SortField
 					{
@@ -169,6 +198,11 @@ public SortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(clust
 						Mode = SortMode.Min,
 						Points = new[] { new GeoLocation(70, -70), new GeoLocation(-12, 12) }
 					},
+					new GeoDistanceSort
+					{
+						Field = "locationPoint",
+						Points = new[] { new GeoLocation(70, -70), new GeoLocation(-12, 12) }
+					},
 					new ScriptSort
 					{
 						Type = "number",
@@ -192,7 +226,7 @@ public SortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(clust
 	 * In Elasticsearch 6.1.0+, using `nested_path` and `nested_filter` for sorting on fields mapped as
 	 * `nested` types is deprecated. Instead, you should use the `nested` sort instead.
 	 */
-	[SkipVersion("<6.1.0", "Only available in Elasticsearch 6.1.0+")]
+	[SkipVersion("<6.5.0", "max_children added in Elasticsearch 6.5.0+")]
 	public class NestedSortUsageTests : SearchUsageTestBase
 	{
 		public NestedSortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(cluster, usage) { }
@@ -216,7 +250,8 @@ public NestedSortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base
 									filter = new
 									{
 										match_all = new { }
-									}
+									},
+									max_children = 50
 								},
 								unmapped_type = "date"
 							}
@@ -238,6 +273,7 @@ public NestedSortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base
 						.Filter(ff => ff
 							.MatchAll()
 						)
+						.MaxChildren(50)
 					)
 				)
 			);
@@ -257,7 +293,8 @@ public NestedSortUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base
 						Nested = new NestedSort
 						{
 							Path = Field<Project>(p => p.Tags),
-							Filter = new MatchAllQuery()
+							Filter = new MatchAllQuery(),
+							MaxChildren = 50
 						}
 					}
 				}
