Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data.Entity/System/Data/Query/PlanCompiler/CommandPlan.cs

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+//---------------------------------------------------------------------
+// <copyright file="CommandPlan.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner  [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Data.Common;
+using md = System.Data.Metadata.Edm;
+using cqt = System.Data.Common.CommandTrees;
+//using System.Diagnostics; // Please use PlanCompiler.Assert instead of Debug.Assert in this class...
+
+// It is fine to use Debug.Assert in cases where you assert an obvious thing that is supposed
+// to prevent from simple mistakes during development (e.g. method argument validation 
+// in cases where it was you who created the variables or the variables had already been validated or 
+// in "else" clauses where due to code changes (e.g. adding a new value to an enum type) the default 
+// "else" block is chosen why the new condition should be treated separately). This kind of asserts are 
+// (can be) helpful when developing new code to avoid simple mistakes but have no or little value in 
+// the shipped product. 
+// PlanCompiler.Assert *MUST* be used to verify conditions in the trees. These would be assumptions 
+// about how the tree was built etc. - in these cases we probably want to throw an exception (this is
+// what PlanCompiler.Assert does when the condition is not met) if either the assumption is not correct 
+// or the tree was built/rewritten not the way we thought it was.
+// Use your judgment - if you rather remove an assert than ship it use Debug.Assert otherwise use
+// PlanCompiler.Assert.
+
+
+//
+// A CommandPlan represents the plan for a query.
+//
+namespace System.Data.Query.PlanCompiler
+{
+    #region CommandInfo
+
+    /// <summary>
+    /// Captures information about a single provider command
+    /// </summary>
+    internal sealed class ProviderCommandInfo
+    {
+        #region public apis
+
+        /// <summary>
+        /// Internal methods to get the command tree
+        /// </summary>
+        internal cqt.DbCommandTree CommandTree
+        {
+            get { return _commandTree; }
+        }
+        #endregion
+
+        #region private state
+        private cqt.DbCommandTree _commandTree;
+        private ProviderCommandInfo _parent;
+        private List<ProviderCommandInfo> _children;
+        #endregion
+
+        #region constructors
+
+        /// <summary>
+        /// Internal constructor for a ProviderCommandInfo object
+        /// </summary>
+        /// <param name="commandTree">command tree for the provider command</param>
+        /// <param name="children">children command infos</param>
+        internal ProviderCommandInfo(cqt.DbCommandTree commandTree, 
+            List<ProviderCommandInfo> children)
+        {
+            _commandTree = commandTree;
+            _children = children;
+
+            if (_children == null)
+            {
+                _children = new List<ProviderCommandInfo>();
+            }
+
+            foreach (ProviderCommandInfo child in _children)
+            {
+                child._parent = this;
+            }
+        }
+        #endregion
+    }
+
+    #endregion
+}