/mcs/class/referencesource/System.Data.Linq/SqlClient/Query/SqlExpander.cs
C# | 349 lines | 306 code | 25 blank | 18 comment | 81 complexity | 409dca123fcb759e071498b8f3a52f1d MD5 | raw file
Possible License(s): GPL-2.0, CC-BY-SA-3.0, LGPL-2.0, MPL-2.0-no-copyleft-exception, LGPL-2.1, Unlicense, Apache-2.0
- using System;
- using System.Collections.Generic;
- using System.Linq.Expressions;
- using System.Reflection;
- using System.Data.Linq;
- using System.Data.Linq.Mapping;
- using System.Data.Linq.Provider;
- using System.Linq;
- using System.Data.Linq.SqlClient;
- using System.Diagnostics.CodeAnalysis;
- namespace System.Data.Linq.SqlClient {
- // duplicates an expression up until a column or column ref is encountered
- // goes 'deep' through alias ref's
- // assumes that columnizing has been done already
- internal class SqlExpander {
- SqlFactory factory;
- internal SqlExpander(SqlFactory factory) {
- this.factory = factory;
- }
- internal SqlExpression Expand(SqlExpression exp) {
- return (new Visitor(this.factory)).VisitExpression(exp);
- }
- class Visitor : SqlDuplicator.DuplicatingVisitor {
- SqlFactory factory;
- Expression sourceExpression;
- internal Visitor(SqlFactory factory)
- : base(true) {
- this.factory = factory;
- }
- internal override SqlExpression VisitColumnRef(SqlColumnRef cref) {
- return cref;
- }
- internal override SqlExpression VisitColumn(SqlColumn col) {
- return new SqlColumnRef(col);
- }
- internal override SqlExpression VisitSharedExpression(SqlSharedExpression shared) {
- return this.VisitExpression(shared.Expression);
- }
- internal override SqlExpression VisitSharedExpressionRef(SqlSharedExpressionRef sref) {
- return this.VisitExpression(sref.SharedExpression.Expression);
- }
- internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
- SqlNode node = aref.Alias.Node;
- if (node is SqlTable || node is SqlTableValuedFunctionCall) {
- return aref;
- }
- SqlUnion union = node as SqlUnion;
- if (union != null) {
- return this.ExpandUnion(union);
- }
- SqlSelect ss = node as SqlSelect;
- if (ss != null) {
- return this.VisitExpression(ss.Selection);
- }
- SqlExpression exp = node as SqlExpression;
- if (exp != null)
- return this.VisitExpression(exp);
- throw Error.CouldNotHandleAliasRef(node.NodeType);
- }
- internal override SqlExpression VisitSubSelect(SqlSubSelect ss) {
- return (SqlExpression)new SqlDuplicator().Duplicate(ss);
- }
- internal override SqlNode VisitLink(SqlLink link) {
- SqlExpression expansion = this.VisitExpression(link.Expansion);
- SqlExpression[] exprs = new SqlExpression[link.KeyExpressions.Count];
- for (int i = 0, n = exprs.Length; i < n; i++) {
- exprs[i] = this.VisitExpression(link.KeyExpressions[i]);
- }
- return new SqlLink(link.Id, link.RowType, link.ClrType, link.SqlType, link.Expression, link.Member, exprs, expansion, link.SourceExpression);
- }
- private SqlExpression ExpandUnion(SqlUnion union) {
- List<SqlExpression> exprs = new List<SqlExpression>(2);
- this.GatherUnionExpressions(union, exprs);
- this.sourceExpression = union.SourceExpression;
- SqlExpression result = this.ExpandTogether(exprs);
- return result;
- }
- private void GatherUnionExpressions(SqlNode node, List<SqlExpression> exprs) {
- SqlUnion union = node as SqlUnion;
- if (union != null) {
- this.GatherUnionExpressions(union.Left, exprs);
- this.GatherUnionExpressions(union.Right, exprs);
- }
- else {
- SqlSelect sel = node as SqlSelect;
- if (sel != null) {
- SqlAliasRef aref = sel.Selection as SqlAliasRef;
- if (aref != null) {
- this.GatherUnionExpressions(aref.Alias.Node, exprs);
- }
- else {
- exprs.Add(sel.Selection);
- }
- }
- }
- }
- [SuppressMessage("Microsoft.Performance", "CA1809:AvoidExcessiveLocals", Justification="These issues are related to our use of if-then and case statements for node types, which adds to the complexity count however when reviewed they are easy to navigate and understand.")]
- [SuppressMessage("Microsoft.Maintainability", "CA1505:AvoidUnmaintainableCode", Justification = "These issues are related to our use of if-then and case statements for node types, which adds to the complexity count however when reviewed they are easy to navigate and understand.")]
- [SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity", Justification = "These issues are related to our use of if-then and case statements for node types, which adds to the complexity count however when reviewed they are easy to navigate and understand.")]
- private SqlExpression ExpandTogether(List<SqlExpression> exprs) {
- switch (exprs[0].NodeType) {
- case SqlNodeType.MethodCall: {
- SqlMethodCall[] mcs = new SqlMethodCall[exprs.Count];
- for (int i = 0; i < mcs.Length; ++i) {
- mcs[i] = (SqlMethodCall)exprs[i];
- }
- List<SqlExpression> expandedArgs = new List<SqlExpression>();
- for (int i = 0; i < mcs[0].Arguments.Count; ++i) {
- List<SqlExpression> args = new List<SqlExpression>();
- for (int j = 0; j < mcs.Length; ++j) {
- args.Add(mcs[j].Arguments[i]);
- }
- SqlExpression expanded = this.ExpandTogether(args);
- expandedArgs.Add(expanded);
- }
- return factory.MethodCall(mcs[0].Method, mcs[0].Object, expandedArgs.ToArray(), mcs[0].SourceExpression);
- }
- case SqlNodeType.ClientCase: {
- // Are they all the same?
- SqlClientCase[] scs = new SqlClientCase[exprs.Count];
- scs[0] = (SqlClientCase)exprs[0];
- for (int i = 1; i < scs.Length; ++i) {
- scs[i] = (SqlClientCase)exprs[i];
- }
- // Expand expressions together.
- List<SqlExpression> expressions = new List<SqlExpression>();
- for (int i = 0; i < scs.Length; ++i) {
- expressions.Add(scs[i].Expression);
- }
- SqlExpression expression = this.ExpandTogether(expressions);
- // Expand individual expressions together.
- List<SqlClientWhen> whens = new List<SqlClientWhen>();
- for (int i = 0; i < scs[0].Whens.Count; ++i) {
- List<SqlExpression> scos = new List<SqlExpression>();
- for (int j = 0; j < scs.Length; ++j) {
- SqlClientWhen when = scs[j].Whens[i];
- scos.Add(when.Value);
- }
- whens.Add(new SqlClientWhen(scs[0].Whens[i].Match, this.ExpandTogether(scos)));
- }
- return new SqlClientCase(scs[0].ClrType, expression, whens, scs[0].SourceExpression);
- }
- case SqlNodeType.TypeCase: {
- // Are they all the same?
- SqlTypeCase[] tcs = new SqlTypeCase[exprs.Count];
- tcs[0] = (SqlTypeCase)exprs[0];
- for (int i = 1; i < tcs.Length; ++i) {
- tcs[i] = (SqlTypeCase)exprs[i];
- }
- // Expand discriminators together.
- List<SqlExpression> discriminators = new List<SqlExpression>();
- for (int i = 0; i < tcs.Length; ++i) {
- discriminators.Add(tcs[i].Discriminator);
- }
- SqlExpression discriminator = this.ExpandTogether(discriminators);
- // Write expanded discriminators back in.
- for (int i = 0; i < tcs.Length; ++i) {
- tcs[i].Discriminator = discriminators[i];
- }
- // Expand individual type bindings together.
- List<SqlTypeCaseWhen> whens = new List<SqlTypeCaseWhen>();
- for (int i = 0; i < tcs[0].Whens.Count; ++i) {
- List<SqlExpression> scos = new List<SqlExpression>();
- for (int j = 0; j < tcs.Length; ++j) {
- SqlTypeCaseWhen when = tcs[j].Whens[i];
- scos.Add(when.TypeBinding);
- }
- SqlExpression expanded = this.ExpandTogether(scos);
- whens.Add(new SqlTypeCaseWhen(tcs[0].Whens[i].Match, expanded));
- }
- return factory.TypeCase(tcs[0].ClrType, tcs[0].RowType, discriminator, whens, tcs[0].SourceExpression);
- }
- case SqlNodeType.New: {
- // first verify all are similar client objects...
- SqlNew[] cobs = new SqlNew[exprs.Count];
- cobs[0] = (SqlNew)exprs[0];
- for (int i = 1, n = exprs.Count; i < n; i++) {
- if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.New)
- throw Error.UnionIncompatibleConstruction();
- cobs[i] = (SqlNew)exprs[1];
- if (cobs[i].Members.Count != cobs[0].Members.Count)
- throw Error.UnionDifferentMembers();
- for (int m = 0, mn = cobs[0].Members.Count; m < mn; m++) {
- if (cobs[i].Members[m].Member != cobs[0].Members[m].Member) {
- throw Error.UnionDifferentMemberOrder();
- }
- }
- }
- SqlMemberAssign[] bindings = new SqlMemberAssign[cobs[0].Members.Count];
- for (int m = 0, mn = bindings.Length; m < mn; m++) {
- List<SqlExpression> mexprs = new List<SqlExpression>();
- for (int i = 0, n = exprs.Count; i < n; i++) {
- mexprs.Add(cobs[i].Members[m].Expression);
- }
- bindings[m] = new SqlMemberAssign(cobs[0].Members[m].Member, this.ExpandTogether(mexprs));
- for (int i = 0, n = exprs.Count; i < n; i++) {
- cobs[i].Members[m].Expression = mexprs[i];
- }
- }
- SqlExpression[] arguments = new SqlExpression[cobs[0].Args.Count];
- for (int m = 0, mn = arguments.Length; m < mn; ++m) {
- List<SqlExpression> mexprs = new List<SqlExpression>();
- for (int i = 0, n = exprs.Count; i < n; i++) {
- mexprs.Add(cobs[i].Args[m]);
- }
- arguments[m] = ExpandTogether(mexprs);
- }
- return factory.New(cobs[0].MetaType, cobs[0].Constructor, arguments, cobs[0].ArgMembers, bindings, exprs[0].SourceExpression);
- }
- case SqlNodeType.Link: {
- SqlLink[] links = new SqlLink[exprs.Count];
- links[0] = (SqlLink)exprs[0];
- for (int i = 1, n = exprs.Count; i < n; i++) {
- if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.Link)
- throw Error.UnionIncompatibleConstruction();
- links[i] = (SqlLink)exprs[i];
- if (links[i].KeyExpressions.Count != links[0].KeyExpressions.Count ||
- links[i].Member != links[0].Member ||
- (links[i].Expansion != null) != (links[0].Expansion != null))
- throw Error.UnionIncompatibleConstruction();
- }
- SqlExpression[] kexprs = new SqlExpression[links[0].KeyExpressions.Count];
- List<SqlExpression> lexprs = new List<SqlExpression>();
- for (int k = 0, nk = links[0].KeyExpressions.Count; k < nk; k++) {
- lexprs.Clear();
- for (int i = 0, n = exprs.Count; i < n; i++) {
- lexprs.Add(links[i].KeyExpressions[k]);
- }
- kexprs[k] = this.ExpandTogether(lexprs);
- for (int i = 0, n = exprs.Count; i < n; i++) {
- links[i].KeyExpressions[k] = lexprs[i];
- }
- }
- SqlExpression expansion = null;
- if (links[0].Expansion != null) {
- lexprs.Clear();
- for (int i = 0, n = exprs.Count; i < n; i++) {
- lexprs.Add(links[i].Expansion);
- }
- expansion = this.ExpandTogether(lexprs);
- for (int i = 0, n = exprs.Count; i < n; i++) {
- links[i].Expansion = lexprs[i];
- }
- }
- return new SqlLink(links[0].Id, links[0].RowType, links[0].ClrType, links[0].SqlType, links[0].Expression, links[0].Member, kexprs, expansion, links[0].SourceExpression);
- }
- case SqlNodeType.Value: {
- /*
- * ExprSet of all literals of the same value reduce to just a single literal.
- */
- SqlValue val0 = (SqlValue)exprs[0];
- for (int i = 1; i < exprs.Count; ++i) {
- SqlValue val = (SqlValue)exprs[i];
- if (!object.Equals(val.Value, val0.Value))
- return this.ExpandIntoExprSet(exprs);
- }
- return val0;
- }
- case SqlNodeType.OptionalValue: {
- if (exprs[0].SqlType.CanBeColumn) {
- goto default;
- }
- List<SqlExpression> hvals = new List<SqlExpression>(exprs.Count);
- List<SqlExpression> vals = new List<SqlExpression>(exprs.Count);
- for (int i = 0, n = exprs.Count; i < n; i++) {
- if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.OptionalValue) {
- throw Error.UnionIncompatibleConstruction();
- }
- SqlOptionalValue sov = (SqlOptionalValue)exprs[i];
- hvals.Add(sov.HasValue);
- vals.Add(sov.Value);
- }
- return new SqlOptionalValue(this.ExpandTogether(hvals), this.ExpandTogether(vals));
- }
- case SqlNodeType.OuterJoinedValue: {
- if (exprs[0].SqlType.CanBeColumn) {
- goto default;
- }
- List<SqlExpression> values = new List<SqlExpression>(exprs.Count);
- for (int i = 0, n = exprs.Count; i < n; i++) {
- if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.OuterJoinedValue) {
- throw Error.UnionIncompatibleConstruction();
- }
- SqlUnary su = (SqlUnary)exprs[i];
- values.Add(su.Operand);
- }
- return factory.Unary(SqlNodeType.OuterJoinedValue, this.ExpandTogether(values));
- }
- case SqlNodeType.DiscriminatedType: {
- SqlDiscriminatedType sdt0 = (SqlDiscriminatedType)exprs[0];
- List<SqlExpression> foos = new List<SqlExpression>(exprs.Count);
- foos.Add(sdt0.Discriminator);
- for (int i = 1, n = exprs.Count; i < n; i++) {
- SqlDiscriminatedType sdtN = (SqlDiscriminatedType)exprs[i];
- if (sdtN.TargetType != sdt0.TargetType) {
- throw Error.UnionIncompatibleConstruction();
- }
- foos.Add(sdtN.Discriminator);
- }
- return factory.DiscriminatedType(this.ExpandTogether(foos), ((SqlDiscriminatedType)exprs[0]).TargetType);
- }
- case SqlNodeType.ClientQuery:
- case SqlNodeType.Multiset:
- case SqlNodeType.Element:
- case SqlNodeType.Grouping:
- throw Error.UnionWithHierarchy();
- default:
- return this.ExpandIntoExprSet(exprs);
- }
- }
- /// <summary>
- /// Expand a set of expressions into a single expr set.
- /// This is typically a fallback when there is no other way to unify a set of expressions.
- /// </summary>
- private SqlExpression ExpandIntoExprSet(List<SqlExpression> exprs) {
- SqlExpression[] rexprs = new SqlExpression[exprs.Count];
- for (int i = 0, n = exprs.Count; i < n; i++) {
- rexprs[i] = this.VisitExpression(exprs[i]);
- }
- return this.factory.ExprSet(rexprs, this.sourceExpression);
- }
- }
- }
- }