Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Data/System/Data/SqlClient/SqlConnectionPoolKey.cs

@@ -0,0 +1,88 @@
+//------------------------------------------------------------------------------
+// <copyright file="ConnectionPoolKey.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+// <owner current="true" primary="false">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Data.SqlClient
+{
+
+    using System;
+    using System.Collections;
+    using System.Data.Common;
+
+    // SqlConnectionPoolKey: Implementation of a key to connection pool groups for specifically to be used for SqlConnection
+    //  Connection string and SqlCredential are used as a key
+    internal class SqlConnectionPoolKey : DbConnectionPoolKey, ICloneable
+    {
+        private SqlCredential _credential;
+        private int _hashValue;
+
+        internal SqlConnectionPoolKey(string connectionString, SqlCredential credential) : base(connectionString)
+        {
+            _credential = credential;
+            CalculateHashCode();
+        }
+
+        private SqlConnectionPoolKey(SqlConnectionPoolKey key) : base (key)
+        {
+             _credential = key.Credential;
+             CalculateHashCode();
+        }
+
+        object ICloneable.Clone()
+        {
+            return new SqlConnectionPoolKey(this);
+        }
+
+        internal override string ConnectionString
+        {
+            get
+            {
+                return base.ConnectionString;
+            }
+
+            set
+            {
+                base.ConnectionString = value;
+                CalculateHashCode();
+            }
+        }
+
+        internal SqlCredential Credential
+        {
+            get
+            {
+                return _credential;
+            }
+        }
+
+
+        public override bool Equals(object obj)
+        {
+            SqlConnectionPoolKey key = obj as SqlConnectionPoolKey;
+
+            return (key != null && _credential == key._credential && ConnectionString == key.ConnectionString);
+        }
+
+        public override int GetHashCode()
+        {
+            return _hashValue;
+        }
+
+        private void CalculateHashCode()
+        {
+            _hashValue = base.GetHashCode();
+
+            if (_credential != null)
+            {
+                unchecked
+                {
+                    _hashValue = _hashValue * 17 + _credential.GetHashCode();
+                }
+            }
+        }
+    }
+}