IndexInfo ctor: Use IEnumerable<IndexInfo> instead of instance + array

Prevents usage of temp collections when Union or Join indexes are built

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClassTable.cs

@@ -120,7 +120,7 @@ private void BuildClassTableIndexes(TypeInfo type)
             var filteredIndex = BuildFilterIndex(type, ancestorIndex, filterByTypes);
             baseIndexes.Push(filteredIndex);
           }
-          var virtualPrimaryIndex = baseIndexes.Count == 1 
+          var virtualPrimaryIndex = baseIndexes.Count == 1
             ? baseIndexes.Pop()
             : BuildJoinIndex(type, baseIndexes);
           type.Indexes.Add(virtualPrimaryIndex);

Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ConcreteTable.cs

@@ -92,11 +92,9 @@ private void BuildConcreteTableIndexes(TypeInfo type)
 
       // Build primary virtual union index
       if (descendants.Count > 0) {
-        var indexesToUnion = new List<IndexInfo>(descendants.Count + 1) { type.Indexes.PrimaryIndex };
-        foreach (var index in descendants.Select(static t => t.Indexes.PrimaryIndex)) {
-          var indexView = BuildViewIndex(type, index);
-          indexesToUnion.Add(indexView);
-        }
+        var indexesToUnion = descendants.Select(t => BuildViewIndex(type, t.Indexes.PrimaryIndex))
+          .Prepend(type.Indexes.PrimaryIndex);
+
         var virtualPrimaryIndex = BuildUnionIndex(type, indexesToUnion);
         type.Indexes.Add(virtualPrimaryIndex);
 

Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.cs

@@ -165,13 +165,10 @@ private void BuildInterfaceIndexes()
                   var filterIndex = BuildFilterIndex(implementor,
                     typedIndex ?? typeIndexes.Dequeue(),
                     NonAbstractTypeWithDescendants(implementor, hierarchyImplementors));
-                  var indexesToJoin = new List<IndexInfo>(1 + typeIndexes.Count);
-                  indexesToJoin.Add(filterIndex);
-                  indexesToJoin.AddRange(typeIndexes);
 
-                  var indexToApplyView = indexesToJoin.Count > 1 
-                    ? BuildJoinIndex(implementor, indexesToJoin) 
-                    : indexesToJoin[0];
+                  var indexToApplyView = typeIndexes.Count > 0
+                    ? BuildJoinIndex(implementor, typeIndexes.Prepend(filterIndex))
+                    : filterIndex;
                   var indexView = BuildViewIndex(@interface, indexToApplyView);
                   underlyingIndex.UnderlyingIndexes.Add(indexView);
                 }
@@ -496,7 +493,7 @@ private IndexInfo BuildTypedIndex(TypeInfo reflectedType, IndexInfo realIndex)
       var attributes = realIndex.Attributes
         & (IndexAttributes.Primary | IndexAttributes.Secondary | IndexAttributes.Unique | IndexAttributes.Abstract)
         | IndexAttributes.Typed | IndexAttributes.Virtual;
-      var result = new IndexInfo(reflectedType, attributes, realIndex, Array.Empty<IndexInfo>());
+      var result = new IndexInfo(reflectedType, attributes, realIndex, addAncestorToUnderlyings: true);
 
       // Adding key columns
       foreach (KeyValuePair<ColumnInfo, Direction> pair in realIndex.KeyColumns) {
@@ -531,7 +528,7 @@ private IndexInfo BuildFilterIndex(TypeInfo reflectedType, IndexInfo indexToFilt
       var attributes = indexToFilter.Attributes
         & (IndexAttributes.Primary | IndexAttributes.Secondary | IndexAttributes.Unique | IndexAttributes.Abstract)
         | IndexAttributes.Filtered | IndexAttributes.Virtual;
-      var result = new IndexInfo(reflectedType, attributes, indexToFilter, Array.Empty<IndexInfo>()) {
+      var result = new IndexInfo(reflectedType, attributes, indexToFilter, addAncestorToUnderlyings: true) {
         FilterByTypes = filterByTypes
       };
 
@@ -560,11 +557,10 @@ private IndexInfo BuildJoinIndex(TypeInfo reflectedType, IEnumerable<IndexInfo>
     {
       var nameBuilder = context.NameBuilder;
       var firstIndex = indexesToJoin.First();
-      var otherIndexes = indexesToJoin.Skip(1).ToArray();
       var attributes = firstIndex.Attributes
         & (IndexAttributes.Primary | IndexAttributes.Secondary | IndexAttributes.Unique)
         | IndexAttributes.Join | IndexAttributes.Virtual;
-      var result = new IndexInfo(reflectedType, attributes, firstIndex, otherIndexes);
+      var result = new IndexInfo(reflectedType, attributes, indexesToJoin);
 
       // Adding key columns
       foreach (KeyValuePair<ColumnInfo, Direction> pair in firstIndex.KeyColumns) {
@@ -645,11 +641,10 @@ private IndexInfo BuildUnionIndex(TypeInfo reflectedType, IEnumerable<IndexInfo>
     {
       var nameBuilder = context.NameBuilder;
       var firstIndex = indexesToUnion.First();
-      var otherIndexes = indexesToUnion.Skip(1).ToArray();
       var attributes = firstIndex.Attributes
         & (IndexAttributes.Primary | IndexAttributes.Secondary | IndexAttributes.Unique)
         | IndexAttributes.Union | IndexAttributes.Virtual;
-      var result = new IndexInfo(reflectedType, attributes, firstIndex, otherIndexes);
+      var result = new IndexInfo(reflectedType, attributes, indexesToUnion);
 
       // Adding key columns
       foreach (KeyValuePair<ColumnInfo, Direction> pair in firstIndex.KeyColumns) {
@@ -682,7 +677,7 @@ private IndexInfo BuildViewIndex(TypeInfo reflectedType, IndexInfo indexToApplyV
       var attributes = indexToApplyView.Attributes
         & (IndexAttributes.Primary | IndexAttributes.Secondary | IndexAttributes.Unique | IndexAttributes.Abstract)
         | IndexAttributes.View | IndexAttributes.Virtual;
-      var result = new IndexInfo(reflectedType, attributes, indexToApplyView, Array.Empty<IndexInfo>());
+      var result = new IndexInfo(reflectedType, attributes, indexToApplyView, addAncestorToUnderlyings: true);
 
       // Adding key columns
       foreach (KeyValuePair<ColumnInfo, Direction> pair in indexToApplyView.KeyColumns) {

Orm/Xtensive.Orm/Orm/Model/IndexInfo.cs

@@ -423,9 +423,10 @@ public IndexInfo(TypeInfo declaringType, IndexAttributes indexAttributes)
     /// Initializes a new instance of this class.
     /// </summary>
     /// <param name="reflectedType">Reflected type.</param>
-    /// <param name="ancestorIndex">The ancestors index.</param>
     /// <param name="indexAttributes"><see cref="IndexAttributes"/> attributes for this instance.</param>
-    public IndexInfo(TypeInfo reflectedType, IndexAttributes indexAttributes, IndexInfo ancestorIndex)
+    /// <param name="ancestorIndex">The ancestors index.</param>
+    /// <param name="addAncestorToUnderlyings"><see langword="true"/> if <paramref name="ancestorIndex"/> should also be treated as underlying index.</param>
+    public IndexInfo(TypeInfo reflectedType, IndexAttributes indexAttributes, IndexInfo ancestorIndex, bool addAncestorToUnderlyings = false)
       : this()
     {
       declaringType = ancestorIndex.DeclaringType;
@@ -436,6 +437,10 @@ public IndexInfo(TypeInfo reflectedType, IndexAttributes indexAttributes, IndexI
       filterExpression = ancestorIndex.FilterExpression;
       declaringIndex = ancestorIndex.DeclaringIndex;
       shortName = ancestorIndex.ShortName;
+
+      if (addAncestorToUnderlyings) {
+        UnderlyingIndexes.Add(ancestorIndex);
+      }
     }
 
     /// <summary>
@@ -445,6 +450,7 @@ public IndexInfo(TypeInfo reflectedType, IndexAttributes indexAttributes, IndexI
     /// <param name="indexAttributes">The index attributes.</param>
     /// <param name="baseIndex">Base index.</param>
     /// <param name="baseIndexes">The base indexes.</param>
+    [Obsolete("Use either IndexInfo(reflectedType, indexAttributes, ancestorIndex, true) in case of one base index or varaint with sequence of indexes")]
     public IndexInfo(TypeInfo reflectedType, IndexAttributes indexAttributes, IndexInfo baseIndex, params IndexInfo[] baseIndexes)
       : this()
     {
@@ -462,5 +468,32 @@ public IndexInfo(TypeInfo reflectedType, IndexAttributes indexAttributes, IndexI
       foreach (IndexInfo info in baseIndexes)
         UnderlyingIndexes.Add(info);
     }
+
+    /// <summary>
+    /// Initializes a new instance of this class.
+    /// </summary>
+    /// <param name="reflectedType">Reflected type.</param>
+    /// <param name="indexAttributes">The index attributes.</param>
+    /// <param name="baseIndexes">The base indexes, first of which will be used as source index properties.</param>
+    public IndexInfo(TypeInfo reflectedType, IndexAttributes indexAttributes, IEnumerable<IndexInfo> baseIndexes)
+      : this()
+    {
+      this.reflectedType = reflectedType;
+      attributes = indexAttributes;
+
+      foreach (var info in baseIndexes) {
+        if (declaringType is null) {
+          declaringType = info.DeclaringType;
+          fillFactor = info.FillFactor;
+          filterExpression = info.FilterExpression;
+          declaringIndex = info.DeclaringIndex;
+          shortName = info.ShortName;
+        }
+        UnderlyingIndexes.Add(info);
+      }
+      if (UnderlyingIndexes.Count == 0) {
+        throw new ArgumentException(Strings.ExSequenceContainsNoElements, nameof(baseIndexes));
+      }
+    }
   }
 }