ProviderVisitors track applyparameter changes during expression tree traversal

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Apply.cs

@@ -1,4 +1,4 @@
-// Copyright (C) 2009-2021 Xtensive LLC.
+// Copyright (C) 2009-2024 Xtensive LLC.
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 // Created by: Denis Krjuchkov
@@ -24,24 +24,24 @@ protected override SqlProvider VisitApply(ApplyProvider provider)
     {
       bool processViaCrossApply;
       switch (provider.SequenceType) {
-      case ApplySequenceType.All:
-        // apply is required
-        if (!providerInfo.Supports(ProviderFeatures.Apply))
-          throw new NotSupportedException();
-        processViaCrossApply = true;
-        break;
-      case ApplySequenceType.First:
-      case ApplySequenceType.FirstOrDefault:
-        // apply is prefered but is not required
-        processViaCrossApply = providerInfo.Supports(ProviderFeatures.Apply);
-        break;
-      case ApplySequenceType.Single:
-      case ApplySequenceType.SingleOrDefault:
-        // apply is not allowed
-        processViaCrossApply = false;
-        break;
-      default:
-        throw new ArgumentOutOfRangeException();
+        case ApplySequenceType.All:
+          // apply is required
+          if (!providerInfo.Supports(ProviderFeatures.Apply))
+            throw new NotSupportedException();
+          processViaCrossApply = true;
+          break;
+        case ApplySequenceType.First:
+        case ApplySequenceType.FirstOrDefault:
+          // apply is prefered but is not required
+          processViaCrossApply = providerInfo.Supports(ProviderFeatures.Apply);
+          break;
+        case ApplySequenceType.Single:
+        case ApplySequenceType.SingleOrDefault:
+          // apply is not allowed
+          processViaCrossApply = false;
+          break;
+        default:
+          throw new ArgumentOutOfRangeException();
       }
 
       var left = Compile(provider.Left);
@@ -64,24 +64,29 @@ protected override SqlProvider VisitApply(ApplyProvider provider)
           return mc;
         });
         var providerVisitor = new CompilableProviderVisitor((p, e) => visitor.Visit(e));
-        providerVisitor.VisitCompilable(provider.Right);
+        _ = providerVisitor.VisitCompilable(provider.Right);
         shouldUseQueryReference = usedOuterColumns.Any(calculatedColumnIndexes.Contains)
           || groupByIsUsed
           || provider.Left.Type.In(ProviderType.Store, ProviderType.Include)
           || left.Header.Columns.Count!=left.Request.Statement.Columns.Count;
       }
 
-      var binding = OuterReferences.Add(
-        provider.ApplyParameter, new Pair<SqlProvider, bool>(left, shouldUseQueryReference));
+      var outerReference = new Pair<SqlProvider, bool>(left, shouldUseQueryReference);
+      var binding = OuterReferences.Add(provider.ApplyParameter, outerReference);
 
       using (binding) {
+        outerReferenceStack.Push(outerReference);
+
         var right = Compile(provider.Right);
 
         var query = processViaCrossApply
           ? ProcessApplyViaCrossApply(provider, left, right)
           : ProcessApplyViaSubqueries(provider, left, right, shouldUseQueryReference);
 
-        return CreateProvider(query, provider, left, right);
+        var result = CreateProvider(query, provider, left, right);
+
+        _ = outerReferenceStack.Pop();
+        return result;
       }
     }
 

Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Helpers.cs

@@ -345,7 +345,9 @@ private SqlExpression GetJoinExpression(SqlExpression leftExpression, SqlExpress
 
     public SqlExpression GetOuterExpression(ApplyParameter parameter, int columnIndex)
     {
-      var reference = OuterReferences[parameter];
+      if (!OuterReferences.TryGetValue(parameter, out var reference)) {
+        reference = outerReferenceStack.Peek();
+      }
       var sqlProvider = reference.First;
       var useQueryReference = reference.Second;
       return useQueryReference

Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.cs

@@ -1,4 +1,4 @@
-// Copyright (C) 2009-2021 Xtensive LLC.
+// Copyright (C) 2009-2024 Xtensive LLC.
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 // Created by: Vakhtina Elena
@@ -23,6 +23,8 @@ namespace Xtensive.Orm.Providers
 {
   public partial class SqlCompiler : Compiler<SqlProvider>
   {
+    protected readonly Stack<Pair<SqlProvider, bool>> outerReferenceStack = new Stack<Pair<SqlProvider, bool>>();
+
     private readonly BooleanExpressionConverter booleanExpressionConverter;
     private readonly Dictionary<SqlColumnStub, SqlExpression> stubColumnMap;
     private readonly ProviderInfo providerInfo;

Orm/Xtensive.Orm/Orm/Rse/Transformation/ColumnMappingInspector.cs

@@ -1,11 +1,12 @@
-// Copyright (C) 2010-2020 Xtensive LLC.
+// Copyright (C) 2010-2024 Xtensive LLC.
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Linq.Expressions;
+using System.Runtime.CompilerServices;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
@@ -21,6 +22,7 @@ internal abstract class ColumnMappingInspector : CompilableProviderVisitor
     private readonly Dictionary<ApplyParameter, List<int>> outerColumnUsages;
     private readonly CompilableProviderVisitor outerColumnUsageVisitor;
     private readonly CompilableProvider rootProvider;
+    private readonly Stack<List<int>> outerColumnUsageStack;
 
     private bool hasGrouping;
 
@@ -195,9 +197,9 @@ protected override Provider VisitApply(ApplyProvider provider)
       var applyParameter = provider.ApplyParameter;
       var currentOuterUsages = new List<int>();
 
-      outerColumnUsages.Add(applyParameter, currentOuterUsages);
-      _ = outerColumnUsageVisitor.VisitCompilable(provider.Right);
-      _ = outerColumnUsages.Remove(applyParameter);
+      using (SetOuterColumnUsage(applyParameter, currentOuterUsages)) {
+        _ = outerColumnUsageVisitor.VisitCompilable(provider.Right);
+      }
 
       leftMapping = Merge(leftMapping, currentOuterUsages);
 
@@ -212,9 +214,10 @@ protected override Provider VisitApply(ApplyProvider provider)
       leftMapping = mappings[provider.Left];
 
       _ = ReplaceMappings(provider.Right, rightMapping);
-      outerColumnUsages.Add(applyParameter, leftMapping);
-      var newRightProvider = VisitCompilable(provider.Right);
-      _ = outerColumnUsages.Remove(applyParameter);
+      CompilableProvider newRightProvider;
+      using (SetOuterColumnUsage(applyParameter, leftMapping)) {
+        newRightProvider = VisitCompilable(provider.Right);
+      }
 
       var pair = OverrideRightApplySource(provider, newRightProvider, rightMapping);
       if (pair.First == null) {
@@ -466,7 +469,7 @@ private void RegisterOuterMapping(ApplyParameter parameter, int value)
 
     private int ResolveOuterMapping(ApplyParameter parameter, int value)
     {
-      var result = outerColumnUsages[parameter].IndexOf(value);
+      var result = GetOuterColumnUsage(parameter).IndexOf(value);
       return result < 0 ? value : result;
     }
 
@@ -514,6 +517,21 @@ private Dictionary<Provider, List<int>> ReplaceMappings(Provider firstNewKey, Li
 
     private void RestoreMappings(Dictionary<Provider, List<int>> savedMappings) => mappings = savedMappings;
 
+    private IDisposable SetOuterColumnUsage(ApplyParameter parameter, List<int> usages)
+    {
+      outerColumnUsages.Add(parameter, usages);
+      outerColumnUsageStack.Push(usages);
+      return new Disposable(
+        x => { 
+          _ = outerColumnUsages.Remove(parameter);
+          _ = outerColumnUsageStack.Pop();
+        });
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private List<int> GetOuterColumnUsage(ApplyParameter parameter) =>
+      outerColumnUsages.TryGetValue(parameter, out var result) ? result : outerColumnUsageStack.Peek();
+
     #endregion
 
     // Constructors
@@ -524,6 +542,7 @@ protected ColumnMappingInspector(CompilableProvider originalProvider)
 
       mappings = new Dictionary<Provider, List<int>>();
       outerColumnUsages = new Dictionary<ApplyParameter, List<int>>();
+      outerColumnUsageStack = new Stack<List<int>>();
       mappingsGatherer = new TupleAccessGatherer((a, b) => { });
 
       var outerMappingsGatherer = new TupleAccessGatherer(RegisterOuterMapping);

Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyPredicateCollector.cs

@@ -1,6 +1,6 @@
-// Copyright (C) 2003-2010 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// Copyright (C) 2009-2024 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 // Created by: Alexander Nikolaev
 // Created:    2009.05.22
 
@@ -26,7 +26,7 @@ public bool TryAdd(FilterProvider filter)
     {
       var applyParameter = parameterSearcher.Find(filter.Predicate);
       if (applyParameter != null) {
-        if (!owner.State.SelfConvertibleApplyProviders[applyParameter]) {
+        if (!owner.State.CheckIfApplyParameterSeflConvertible(applyParameter)) {
           SaveApplyPredicate(filter, applyParameter);
           return true;
         }

Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyProviderCorrectorRewriter.cs

@@ -1,6 +1,6 @@
-// Copyright (C) 2003-2010 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// Copyright (C) 2009-2024 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 // Created by: Alexander Nikolaev
 // Created:    2009.05.15
 
@@ -21,28 +21,41 @@ internal sealed class ApplyProviderCorrectorRewriter : CompilableProviderVisitor
   {
     #region Nested types: CorrectorState
 
-    public sealed class CorrectorState : IDisposable
+    internal sealed class CorrectorState : IDisposable
     {
       private readonly CorrectorState previousState;
       private readonly ApplyProviderCorrectorRewriter owner;
+      private readonly Stack<bool> selfConvertibleApplyProviderStack;
+      private readonly Dictionary<ApplyParameter, bool> selfConvertibleApplyProviders;
+
       private bool isDisposed;
 
       public 
         Dictionary<ApplyParameter, List<Pair<Expression<Func<Tuple, bool>>, ColumnCollection>>> 
         Predicates { get; set; }
 
-      public Dictionary<ApplyParameter, bool> SelfConvertibleApplyProviders { get; set; }
+      public Dictionary<ApplyParameter, List<Pair<CalculateProvider, ColumnCollection>>> CalculateProviders { get; set; }
 
-      public Dictionary<ApplyParameter, List<Pair<CalculateProvider, ColumnCollection>>> 
-        CalculateProviders { get; set; }
+      public Dictionary<CalculateProvider, List<Pair<Expression<Func<Tuple, bool>>, ColumnCollection>>> CalculateFilters { get; set; }
 
-      public Dictionary<CalculateProvider, List<Pair<Expression<Func<Tuple, bool>>, ColumnCollection>>>
-        CalculateFilters { get; set; }
+      public bool ExistsApplyProviderRequiringConversion => Predicates.Count > 0 || CalculateProviders.Count > 0;
 
-      public bool ExistsApplyProviderRequiringConversion {
-        get { return Predicates.Count > 0 || CalculateProviders.Count > 0;}
+      public Disposable SetIfApplyParameterConvertible(ApplyParameter parameter, bool isSelfConvertibleApply)
+      {
+        selfConvertibleApplyProviders.Add(parameter, isSelfConvertibleApply);
+        selfConvertibleApplyProviderStack.Push(isSelfConvertibleApply);
+        return new Disposable(
+          x => { 
+            _ = selfConvertibleApplyProviders.Remove(parameter);
+            _ = selfConvertibleApplyProviderStack.Pop();
+          });
       }
 
+      public bool CheckIfApplyParameterSeflConvertible(ApplyParameter parameter) =>
+        selfConvertibleApplyProviders.TryGetValue(parameter, out var result)
+          ? result
+          : selfConvertibleApplyProviderStack.Peek();
+
 
       // Constructors
 
@@ -57,10 +70,12 @@ public CorrectorState(ApplyProviderCorrectorRewriter owner)
           new Dictionary<CalculateProvider, List<Pair<Expression<Func<Tuple, bool>>, ColumnCollection>>>();
         previousState = owner.State;
         if (previousState == null) {
-          SelfConvertibleApplyProviders = new Dictionary<ApplyParameter, bool>();
+          selfConvertibleApplyProviders = new Dictionary<ApplyParameter, bool>();
+          selfConvertibleApplyProviderStack = new Stack<bool>();
         }
         else {
-          SelfConvertibleApplyProviders = previousState.SelfConvertibleApplyProviders;
+          selfConvertibleApplyProviders = previousState.selfConvertibleApplyProviders;
+          selfConvertibleApplyProviderStack = previousState.selfConvertibleApplyProviderStack;
         }
         owner.State = this;
       }
@@ -149,9 +164,9 @@ protected override Provider VisitApply(ApplyProvider provider)
       CompilableProvider left;
       CompilableProvider right;
       var isSelfConvertibleApply = provider.SequenceType != ApplySequenceType.All;
-      State.SelfConvertibleApplyProviders.Add(provider.ApplyParameter, isSelfConvertibleApply);
-      VisitBinaryProvider(provider, out left, out right);
-      State.SelfConvertibleApplyProviders.Remove(provider.ApplyParameter);
+      using (State.SetIfApplyParameterConvertible(provider.ApplyParameter, isSelfConvertibleApply)) {
+        VisitBinaryProvider(provider, out left, out right);
+      }
 
       if (isSelfConvertibleApply) {
         return ProcesSelfConvertibleApply(provider, left, right);

Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateProviderCollector.cs

@@ -1,6 +1,6 @@
-// Copyright (C) 2003-2010 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// Copyright (C) 2009-2024 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 // Created by: Alexander Nikolaev
 // Created:    2009.05.22
 
@@ -29,7 +29,7 @@ public bool TryAdd(CalculateProvider provider)
       if (applyParameters.Count > 1)
         ApplyProviderCorrectorRewriter.ThrowInvalidOperationException();
       var applyParameter = applyParameters[0];
-      if (owner.State.SelfConvertibleApplyProviders[applyParameter])
+      if (owner.State.CheckIfApplyParameterSeflConvertible(applyParameter))
         return false;
       var newPair = new Pair<CalculateProvider, ColumnCollection>(provider, provider.Header.Columns);
       if (owner.State.CalculateProviders.ContainsKey(applyParameter))

Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnRemover.cs

@@ -1,6 +1,6 @@
-// Copyright (C) 2003-2010 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// Copyright (C) 2009-2024 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 // Created by: Alexey Gamzov
 // Created:    2009.10.12
 
@@ -23,7 +23,12 @@ protected override Pair<CompilableProvider, List<int>> OverrideRightApplySource(
       var currentMapping = mappings[applyProvider.Right];
       if (currentMapping.SequenceEqual(requestedMapping))
         return base.OverrideRightApplySource(applyProvider, provider, requestedMapping);
-      var selectProvider = new SelectProvider(provider, requestedMapping.ToArray());
+      var selectingRequestedMapping = requestedMapping.ToArray();
+      for (int i = 0, count = requestedMapping.Count; i < count; i++) {
+        selectingRequestedMapping[i] = currentMapping.IndexOf(selectingRequestedMapping[i]);
+      }
+
+      var selectProvider = new SelectProvider(provider, selectingRequestedMapping);
       return new Pair<CompilableProvider, List<int>>(selectProvider, requestedMapping);
     }