Make KeyField be a record struct (#339) (#343)

* Make `KeyField` readonly struct (#339)

* Use `FrozenSet`

* .NET compatible syntax

* .NET compatible syntax

* missed static

* EnsureCapacity()

* Fix ValidateHierarchy

Author: SergeiPavlov

Orm/Xtensive.Orm/Orm/Building/Builders/AttributeProcessor.cs

@@ -55,24 +55,26 @@ public void Process(HierarchyDef hierarchyDef, FieldDef fieldDef, KeyAttribute a
         "attribute.Position");
 
       var keyField = new KeyField(fieldDef.Name, attribute.Direction);
+      var hierarchyDefKeyFields = hierarchyDef.KeyFields;
 
-      if (hierarchyDef.KeyFields.Count > attribute.Position) {
-        var current = hierarchyDef.KeyFields[attribute.Position];
-        if (current != null) {
+      if (hierarchyDefKeyFields.Count > attribute.Position) {
+        var current = hierarchyDefKeyFields[attribute.Position];
+        if (current != default) {
           throw new DomainBuilderException(string.Format(Strings.ExKeyFieldsXAndXHaveTheSamePositionX, current.Name,
             fieldDef.Name, attribute.Position));
         }
 
-        hierarchyDef.KeyFields[attribute.Position] = keyField;
+        hierarchyDefKeyFields[attribute.Position] = keyField;
       }
       else {
-        // Adding null stubs for not yet processed key fields
-        while (hierarchyDef.KeyFields.Count < attribute.Position) {
-          hierarchyDef.KeyFields.Add(null);
+        // Adding default stubs for not yet processed key fields
+        hierarchyDefKeyFields.EnsureCapacity(attribute.Position + 1);
+        while (hierarchyDefKeyFields.Count < attribute.Position) {
+          hierarchyDefKeyFields.Add(default);
         }
 
         // Finally adding target key field at the specified position
-        hierarchyDef.KeyFields.Add(keyField);
+        hierarchyDefKeyFields.Add(keyField);
       }
     }
 

Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDef.cs

@@ -25,7 +25,7 @@ public sealed class HierarchyDef : Node
     /// <summary>
     /// Gets the fields that are included in the key for this hierarchy.
     /// </summary>
-    public List<KeyField> KeyFields { get; private set; }
+    public List<KeyField> KeyFields { get; } = new(WellKnown.MaxKeyFieldNumber);
 
     /// <summary>
     /// Gets the <see cref="InheritanceSchema"/> for this hierarchy.
@@ -58,9 +58,8 @@ public sealed class HierarchyDef : Node
     internal HierarchyDef(TypeDef root)
     {
       Root = root;
-      KeyFields = new List<KeyField>(WellKnown.MaxKeyFieldNumber);
       IsClustered = true;
       KeyGeneratorKind = KeyGeneratorKind.Default;
     }
   }
-}
+}

Orm/Xtensive.Orm/Orm/Building/FixupActionProcessor.cs

@@ -180,7 +180,7 @@ public void Process(AddPrimaryIndexAction action)
 
       var hierarchyDef = context.ModelDef.FindHierarchy(hierarchyRoot);
 
-      foreach (KeyField pair in hierarchyDef.KeyFields)
+      foreach (var pair in hierarchyDef.KeyFields)
         generatedIndex.KeyFields.Add(pair.Name, pair.Direction);
 
       // Check if user added secondary index equal to auto-generated primary index

Orm/Xtensive.Orm/Orm/Building/ModelInspector.cs

@@ -200,7 +200,7 @@ public static void Inspect(BuildingContext context, HierarchyDef hierarchyDef)
       }
 
       // Should TypeId field be added to key fields?
-      if (hierarchyDef.IncludeTypeId && hierarchyDef.KeyFields.Find(f => f.Name == WellKnown.TypeIdFieldName) == null) {
+      if (hierarchyDef.IncludeTypeId && hierarchyDef.KeyFields.All(f => f.Name != WellKnown.TypeIdFieldName)) {
         context.ModelInspectionResult.Register(new AddTypeIdToKeyFieldsAction(hierarchyDef));
       }
 

Orm/Xtensive.Orm/Orm/Building/Validator.cs

@@ -4,8 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.12
 
-using System;
-using System.Collections.Generic;
+using System.Collections.Frozen;
 using System.Text.RegularExpressions;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Internals;
@@ -14,12 +13,13 @@
 
 namespace Xtensive.Orm.Building
 {
-  internal class Validator
+  internal class Validator(IEnumerable<Type> validFieldTypes)
   {
-    private readonly HashSet<Type> validFieldTypes;
-    private readonly Regex columnNamingRule;
-    private readonly Regex typeNamingRule;
-    private readonly Regex fieldNamingRule;
+    private static readonly Regex ColumnNamingRule = new(@"^[\w][\w\-\.]*$", RegexOptions.Compiled | RegexOptions.CultureInvariant);
+    private static readonly Regex TypeNamingRule = new(@"^[\w][\w\-\.\(\),]*$", RegexOptions.Compiled | RegexOptions.CultureInvariant);
+    private static readonly Regex FieldNamingRule = new(@"^[\w][\w\-\.]*$", RegexOptions.Compiled | RegexOptions.CultureInvariant);
+
+    private readonly FrozenSet<Type> validFieldTypes = validFieldTypes.Append(WellKnownOrmTypes.Key).ToFrozenSet();
 
     /// <summary>
     /// Determines whether the specified name is valid.
@@ -41,13 +41,13 @@ public void ValidateName(string name, ValidationRule rule)
         case ValidationRule.Type:
         case ValidationRule.Schema:
         case ValidationRule.Database:
-          namingRule = typeNamingRule;
+          namingRule = TypeNamingRule;
           break;
         case ValidationRule.Field:
-          namingRule = fieldNamingRule;
+          namingRule = FieldNamingRule;
           break;
         case ValidationRule.Column:
-          namingRule = columnNamingRule;
+          namingRule = ColumnNamingRule;
           break;
         default:
           throw new ArgumentOutOfRangeException();
@@ -95,7 +95,7 @@ public void ValidateHierarchy(HierarchyDef hierarchyDef)
         }
 
         // if one of key fields is TypeId field and number of fields == 2 then it is OK
-        if (keyFields.Count == 2 && keyFields.Find(f => f.Name == WellKnown.TypeIdFieldName) != null) {
+        if (keyFields.Count == 2 && keyFields.Any(f => f.Name == WellKnown.TypeIdFieldName)) {
           throw new DomainBuilderException(Strings.ExDefaultGeneratorCanServeHierarchyWithExactlyOneKeyField);
         }
       }
@@ -257,17 +257,6 @@ internal void EnsureIsNullable(Type valueType)
       }
     }
 
-    // Type initializer
-
-    public Validator(IEnumerable<Type> validFieldTypes)
-    {
-      columnNamingRule = new Regex(@"^[\w][\w\-\.]*$", RegexOptions.Compiled | RegexOptions.CultureInvariant);
-      typeNamingRule = new Regex(@"^[\w][\w\-\.\(\),]*$", RegexOptions.Compiled | RegexOptions.CultureInvariant);
-      fieldNamingRule = new Regex(@"^[\w][\w\-\.]*$", RegexOptions.Compiled | RegexOptions.CultureInvariant);
-
-      this.validFieldTypes = new HashSet<Type>(validFieldTypes) {WellKnownOrmTypes.Key};
-    }
-
     public void ValidateHierarchyEquality(TypeDef @interface, HierarchyDef first, HierarchyDef second)
     {
       // TypeId mode must match
@@ -277,17 +266,20 @@ public void ValidateHierarchyEquality(TypeDef @interface, HierarchyDef first, Hi
           @interface.Name, first.Root.Name, second.Root.Name));
       }
 
+      var firstKeyFields = first.KeyFields;
+      var secondKeyFields = second.KeyFields;
+
       // Number of key fields must match
-      if (first.KeyFields.Count != second.KeyFields.Count) {
+      if (firstKeyFields.Count != secondKeyFields.Count) {
         throw new DomainBuilderException(string.Format(
           Strings.ExImplementorsOfXInterfaceBelongToHierarchiesWithDifferentKeyStructureYZ,
           @interface.Name, first.Root.Name, second.Root.Name));
       }
 
       // Type of each key field must match
-      for (var i = 0; i < first.KeyFields.Count; i++) {
-        var masterField = first.Root.Fields[first.KeyFields[i].Name];
-        var candidateField = second.Root.Fields[second.KeyFields[i].Name];
+      for (var i = 0; i < firstKeyFields.Count; i++) {
+        var masterField = first.Root.Fields[firstKeyFields[i].Name];
+        var candidateField = second.Root.Fields[secondKeyFields[i].Name];
         if (masterField.ValueType != candidateField.ValueType) {
           throw new DomainBuilderException(string.Format(
             Strings.ExImplementorsOfXInterfaceBelongToHierarchiesWithDifferentKeyStructureYZ,

Orm/Xtensive.Orm/Orm/Model/KeyField.cs

@@ -4,51 +4,12 @@
 // Created by: Dmitri Maximov
 // Created:    2007.12.28
 
-using System;
 using Xtensive.Core;
 
+namespace Xtensive.Orm.Model;
 
-namespace Xtensive.Orm.Model
-{
-  /// <summary>
-  /// Describes a field that is a part of a primary key.
-  /// </summary>
-  [Serializable]
-  public sealed class KeyField : Node
-  {
-    /// <summary>
-    /// Gets or sets the direction.
-    /// </summary>
-    public Direction Direction { get; private set; }
-
-    /// <inheritdoc/>
-    public override int GetHashCode() => HashCode.Combine(Name, Direction);
-
-    /// <inheritdoc/>
-    public override bool Equals(object obj) =>
-      ReferenceEquals(this, obj)
-      || obj is KeyField kf && Name == kf.Name && Direction == kf.Direction;
-
-
-    // Constructors
-
-    /// <summary>
-    /// Initializes a new instance of this class.
-    /// </summary>
-    /// <param name="name">The name.</param>
-    public KeyField(string name)
-      : this(name, Direction.Positive)
-    {
-    }
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="KeyField"/> class.
-    /// </summary>
-    /// <param name="name">The name.</param>
-    /// <param name="direction">The direction.</param>
-    public KeyField(string name, Direction direction) : base(name)
-    {
-      Direction = direction;
-    }
-  }
-}
+/// <summary>
+/// Describes a field that is a part of a primary key.
+/// </summary>
+[Serializable]
+public record struct KeyField(string Name, Direction Direction = Direction.Positive);

Orm/Xtensive.Orm/Orm/Model/ModelVisitor.cs

@@ -27,7 +27,6 @@ protected virtual TResult Visit(Node node) =>
         DomainModel domainModel => VisitDomainModel(domainModel),
         KeyInfo keyProviderInfo => VisitKeyInfo(keyProviderInfo),
         SequenceInfo sequenceInfo => VisitSequenceInfo(sequenceInfo),
-        KeyField keyField => VisitKeyField(keyField),
         AssociationInfo association => VisitAssociationInfo(association),
         FieldInfo field => VisitFieldInfo(field),
         TypeInfo type => VisitTypeInfo(type),
@@ -38,13 +37,6 @@ protected virtual TResult Visit(Node node) =>
         _ => throw new ArgumentException(Strings.ExNodeTypeIsUnknown, "node")
       };
 
-    /// <summary>
-    /// Visits key field.
-    /// </summary>
-    /// <param name="keyField">The key field.</param>
-    /// <returns>Visit result.</returns>
-    protected abstract TResult VisitKeyField(KeyField keyField);
-
     /// <summary>
     /// Visits a column.
     /// </summary>
@@ -114,4 +106,4 @@ protected virtual TResult Visit(Node node) =>
     /// <param name="fullTextIndex">Full index of the text.</param>
     protected abstract TResult VisitFullTextIndexInfo(FullTextIndexInfo fullTextIndex);
   }
-}
+}

Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainModelConverter.cs

@@ -337,13 +337,6 @@ private IEnumerable<TableInfo> CreateTables(IndexInfo index)
 
     #region Not supported
 
-    /// <inheritdoc/>
-    /// <exception cref="NotSupportedException">Method is not supported.</exception>
-    protected override IPathNode VisitKeyField(KeyField keyField)
-    {
-      throw new NotSupportedException(String.Format(Strings.ExVisitKeyFieldIsNotSupportedByX, typeof (DomainModelConverter)));
-    }
-
     /// <inheritdoc/>
     /// <exception cref="NotSupportedException">Method is not supported.</exception>
     protected override IPathNode VisitFieldInfo(FieldInfo field)