Set of improvements of Sql translation subsystem

Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.cs

@@ -28,13 +28,13 @@ internal sealed partial class ExpressionProcessor : ExpressionVisitor<SqlExpress
     private readonly StorageDriver driver;
     private readonly BooleanExpressionConverter booleanExpressionConverter;
     private readonly IMemberCompilerProvider<SqlExpression> memberCompilerProvider;
-    private readonly List<SqlExpression>[] sourceColumns;
+    private readonly IReadOnlyList<SqlExpression>[] sourceColumns;
     private readonly ExpressionEvaluator evaluator;
     private readonly ParameterExtractor parameterExtractor;
     private readonly LambdaExpression lambda;
     private readonly HashSet<QueryParameterBinding> bindings;
     private readonly List<ParameterExpression> activeParameters;
-    private readonly Dictionary<ParameterExpression, List<SqlExpression>> sourceMapping;
+    private readonly Dictionary<ParameterExpression, IReadOnlyList<SqlExpression>> sourceMapping;
     private readonly SqlCompiler compiler;
 
     private readonly Dictionary<QueryParameterIdentity, QueryParameterBinding> bindingsWithIdentity
@@ -448,7 +448,7 @@ private SqlExpression TryUnwrapEnum(SqlContainer container)
     // Constructors
 
     public ExpressionProcessor(
-      LambdaExpression lambda, HandlerAccessor handlers, SqlCompiler compiler, params List<SqlExpression>[] sourceColumns)
+      LambdaExpression lambda, HandlerAccessor handlers, SqlCompiler compiler, params IReadOnlyList<SqlExpression>[] sourceColumns)
     {
       ArgumentValidator.EnsureArgumentNotNull(lambda, "lambda");
       ArgumentValidator.EnsureArgumentNotNull(handlers, "handlers");
@@ -478,7 +478,7 @@ public ExpressionProcessor(
         throw Exceptions.InternalError(Strings.ExParametersCountIsNotSameAsSourceColumnListsCount, OrmLog.Instance);
       if (sourceColumns.Any(list => list.Any(c => c.IsNullReference())))
         throw Exceptions.InternalError(Strings.ExSourceColumnListContainsNullValues, OrmLog.Instance);
-      sourceMapping = new Dictionary<ParameterExpression, List<SqlExpression>>();
+      sourceMapping = new Dictionary<ParameterExpression, IReadOnlyList<SqlExpression>>();
     }
   }
 }

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

@@ -92,10 +92,11 @@ private SqlSelect ProcessApplyViaSubqueries(ApplyProvider provider, SqlProvider
       if (shouldUseQueryReference) {
         var leftTable = left.PermanentReference;
         query = SqlDml.Select(leftTable);
-        query.Columns.AddRange(leftTable.Columns.Cast<SqlColumn>());
+        query.Columns.AddRange(leftTable.Columns);
       }
-      else
+      else {
         query = left.Request.Statement.ShallowClone();
+      }
 
       var isApplyExistence =
         provider.Right.Type==ProviderType.Existence ||
@@ -166,15 +167,15 @@ private SqlSelect ProcessApplyViaCrossApply(ApplyProvider provider, SqlProvider
         ? left.PermanentReference
         : left.Request.Statement.From;
       var leftColumns = leftShouldUseReference
-        ? leftTable.Columns.Cast<SqlColumn>()
+        ? (IReadOnlyList<SqlColumn>) leftTable.Columns
         : left.Request.Statement.Columns;
 
       var rightShouldUseReference = ShouldUseQueryReference(provider, right);
       var rightTable = rightShouldUseReference
         ? right.PermanentReference
         : right.Request.Statement.From;
       var rightColumns = rightShouldUseReference
-        ? rightTable.Columns.Cast<SqlColumn>()
+        ? (IReadOnlyList<SqlColumn>) rightTable.Columns
         : right.Request.Statement.Columns;
 
       var joinType = provider.ApplyType==JoinType.LeftOuter
@@ -185,8 +186,8 @@ private SqlSelect ProcessApplyViaCrossApply(ApplyProvider provider, SqlProvider
         joinType,
         leftTable,
         rightTable,
-        leftColumns.ToList(),
-        rightColumns.ToList());
+        leftColumns,
+        rightColumns);
 
       var query = SqlDml.Select(joinedTable);
       if (!leftShouldUseReference)

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

@@ -67,7 +67,7 @@ protected virtual string ProcessAliasedName(string name)
     }
 
     protected Pair<SqlExpression, IEnumerable<QueryParameterBinding>> ProcessExpression(LambdaExpression le,
-      params List<SqlExpression>[] sourceColumns)
+      params IReadOnlyList<SqlExpression>[] sourceColumns)
     {
       var processor = new ExpressionProcessor(le, Handlers, this, sourceColumns);
       var result = new Pair<SqlExpression, IEnumerable<QueryParameterBinding>>(
@@ -81,7 +81,7 @@ protected static SqlSelect ExtractSqlSelect(CompilableProvider origin, SqlProvid
       if (ShouldUseQueryReference(origin, compiledSource)) {
         var queryRef = compiledSource.PermanentReference;
         var query = SqlDml.Select(queryRef);
-        query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+        query.Columns.AddRange(queryRef.Columns);
         return query;
       }
       return sourceSelect.ShallowClone();

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

@@ -94,7 +94,7 @@ private SqlSelect BuildUnionQuery(IndexInfo index)
 
       var unionRef = SqlDml.QueryRef(result);
       var query = SqlDml.Select(unionRef);
-      query.Columns.AddRange(unionRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(unionRef.Columns);
       return query;
     }
 

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

@@ -88,7 +88,7 @@ private SqlProvider VisitSkipRowNumber(SkipProvider provider)
       var source = compiledSource.Request.Statement;
       var queryRef = SqlDml.QueryRef(source);
       var query = SqlDml.Select(queryRef);
-      query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(queryRef.Columns);
       query.Where = queryRef.Columns.Last() > skipParameterBinding.ParameterReference;
       return CreateProvider(query, bindings, provider, compiledSource);
     }
@@ -101,7 +101,7 @@ private SqlProvider VisitTakeRowNumber(TakeProvider provider)
       var source = compiledSource.Request.Statement;
       var queryRef = SqlDml.QueryRef(source);
       var query = SqlDml.Select(queryRef);
-      query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(queryRef.Columns);
       query.Where = queryRef.Columns.Last() <= takeParameterBinding.ParameterReference;
       return CreateProvider(query, bindings, provider, compiledSource);
     }
@@ -116,7 +116,7 @@ private SqlProvider VisitPagingRowNumber(PagingProvider provider)
       var queryRef = SqlDml.QueryRef(source);
       var query = SqlDml.Select(queryRef);
       var rowNumberColumn = queryRef.Columns.Last();
-      query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(queryRef.Columns);
       query.Where = SqlDml.Between(rowNumberColumn,
         fromParameterBinding.ParameterReference,
         toParameterBinding.ParameterReference);

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

@@ -129,10 +129,12 @@ protected override SqlProvider VisitDistinct(DistinctProvider provider)
       if (!sourceSelect.Limit.IsNullReference() || !sourceSelect.Offset.IsNullReference()) {
         var queryRef = SqlDml.QueryRef(sourceSelect);
         query = SqlDml.Select(queryRef);
-        query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+        query.Columns.AddRange(queryRef.Columns);
       }
-      else
+      else {
         query = sourceSelect.ShallowClone();
+      }
+
       query.Distinct = true;
       return CreateProvider(query, provider, source);
     }
@@ -173,7 +175,7 @@ protected override SqlProvider VisitJoin(JoinProvider provider)
         ? left.PermanentReference
         : left.Request.Statement.From;
       var leftColumns = leftShouldUseReference
-        ? leftTable.Columns.Cast<SqlColumn>()
+        ? (IReadOnlyList<SqlColumn>) leftTable.Columns
         : left.Request.Statement.Columns;
       var leftExpressions = leftShouldUseReference
         ? leftTable.Columns.Cast<SqlExpression>().ToList()
@@ -184,7 +186,7 @@ protected override SqlProvider VisitJoin(JoinProvider provider)
         ? right.PermanentReference
         : right.Request.Statement.From;
       var rightColumns = rightShouldUseReference
-        ? rightTable.Columns.Cast<SqlColumn>()
+        ? (IReadOnlyList<SqlColumn>) rightTable.Columns
         : right.Request.Statement.Columns;
       var rightExpressions = rightShouldUseReference
         ? rightTable.Columns.Cast<SqlExpression>().ToList()
@@ -205,8 +207,8 @@ protected override SqlProvider VisitJoin(JoinProvider provider)
         joinType,
         leftTable,
         rightTable,
-        leftColumns.ToList(),
-        rightColumns.ToList(),
+        leftColumns,
+        rightColumns,
         joinExpression);
 
       var query = SqlDml.Select(joinedTable);
@@ -229,21 +231,21 @@ protected override SqlProvider VisitPredicateJoin(PredicateJoinProvider provider
         ? left.PermanentReference
         : left.Request.Statement.From;
       var leftColumns = leftShouldUseReference
-        ? leftTable.Columns.Cast<SqlColumn>()
+        ? (IReadOnlyList<SqlColumn>) leftTable.Columns
         : left.Request.Statement.Columns;
       var leftExpressions = leftShouldUseReference
-        ? leftTable.Columns.Cast<SqlExpression>().ToList()
+        ? (IReadOnlyList<SqlExpression>) leftTable.Columns
         : ExtractColumnExpressions(left.Request.Statement);
 
       var rightShouldUseReference = ShouldUseQueryReference(provider, right);
       var rightTable = rightShouldUseReference
         ? right.PermanentReference
         : right.Request.Statement.From;
       var rightColumns = rightShouldUseReference
-        ? rightTable.Columns.Cast<SqlColumn>()
+        ? (IReadOnlyList<SqlColumn>) rightTable.Columns
         : right.Request.Statement.Columns;
       var rightExpressions = rightShouldUseReference
-        ? rightTable.Columns.Cast<SqlExpression>().ToList()
+        ? (IReadOnlyList<SqlExpression>) rightTable.Columns
         : ExtractColumnExpressions(right.Request.Statement);
 
 
@@ -257,8 +259,8 @@ protected override SqlProvider VisitPredicateJoin(PredicateJoinProvider provider
         joinType,
         leftTable,
         rightTable,
-        leftColumns.ToList(),
-        rightColumns.ToList(),
+        leftColumns,
+        rightColumns,
         joinExpression);
 
       var query = SqlDml.Select(joinedTable);
@@ -308,10 +310,18 @@ protected override SqlProvider VisitSelect(SelectProvider provider)
     {
       var compiledSource = Compile(provider.Source);
 
-      SqlSelect query = ExtractSqlSelect(provider, compiledSource);
-      var originalColumns = query.Columns.ToList();
-      query.Columns.Clear();
-      query.Columns.AddRange(provider.ColumnIndexes.Select(i => originalColumns[i]));
+      var query = ExtractSqlSelect(provider, compiledSource);
+      var queryColumns = query.Columns;
+      var columnIndexes = provider.ColumnIndexes;
+
+      var newIndex = 0;
+      var newColumns = new SqlColumn[columnIndexes.Count];
+      foreach (var index in columnIndexes) {
+        newColumns[newIndex++] = queryColumns[index];
+      }
+
+      queryColumns.Clear();
+      queryColumns.AddRange(newColumns);
 
       return CreateProvider(query, provider, compiledSource);
     }
@@ -407,7 +417,7 @@ protected override SqlProvider VisitIntersect(IntersectProvider provider)
       var queryRef = SqlDml.QueryRef(result);
 
       SqlSelect query = SqlDml.Select(queryRef);
-      query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(queryRef.Columns);
 
       return CreateProvider(query, provider, left, right);
     }
@@ -431,7 +441,7 @@ protected override SqlProvider VisitExcept(ExceptProvider provider)
       var result = SqlDml.Except(leftSelect, rightSelect);
       var queryRef = SqlDml.QueryRef(result);
       SqlSelect query = SqlDml.Select(queryRef);
-      query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(queryRef.Columns);
 
       return CreateProvider(query, provider, left, right);
     }
@@ -455,7 +465,7 @@ protected override SqlProvider VisitConcat(ConcatProvider provider)
       var result = SqlDml.UnionAll(leftSelect, rightSelect);
       var queryRef = SqlDml.QueryRef(result);
       SqlSelect query = SqlDml.Select(queryRef);
-      query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(queryRef.Columns);
 
       return CreateProvider(query, provider, left, right);
     }
@@ -479,7 +489,7 @@ protected override SqlProvider VisitUnion(UnionProvider provider)
       var result = SqlDml.Union(leftSelect, rightSelect);
       var queryRef = SqlDml.QueryRef(result);
       SqlSelect query = SqlDml.Select(queryRef);
-      query.Columns.AddRange(queryRef.Columns.Cast<SqlColumn>());
+      query.Columns.AddRange(queryRef.Columns);
 
       return CreateProvider(query, provider, left, right);
     }