Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/ExtensionCollection.cs

@@ -0,0 +1,117 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.ServiceModel
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Collections.ObjectModel;
+    using System.Runtime.Serialization;
+
+    public sealed class ExtensionCollection<T> : SynchronizedCollection<IExtension<T>>, IExtensionCollection<T>
+        where T : IExtensibleObject<T>
+    {
+        T owner;
+
+        public ExtensionCollection(T owner)
+        {
+            if (owner == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("owner");
+
+            this.owner = owner;
+        }
+
+        public ExtensionCollection(T owner, object syncRoot)
+            : base(syncRoot)
+        {
+            if (owner == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("owner");
+
+            this.owner = owner;
+        }
+
+        bool ICollection<IExtension<T>>.IsReadOnly
+        {
+            get { return false; }
+        }
+
+        protected override void ClearItems()
+        {
+            IExtension<T>[] array;
+
+            lock (this.SyncRoot)
+            {
+                array = new IExtension<T>[this.Count];
+                this.CopyTo(array, 0);
+                base.ClearItems();
+
+                foreach (IExtension<T> extension in array)
+                {
+                    extension.Detach(this.owner);
+                }
+            }
+        }
+
+        public E Find<E>()
+        {
+            List<IExtension<T>> items = this.Items;
+
+            lock (this.SyncRoot)
+            {
+                for (int i = this.Count - 1; i >= 0; i--)
+                {
+                    IExtension<T> item = items[i];
+                    if (item is E)
+                        return (E)item;
+                }
+            }
+
+            return default(E);
+        }
+
+        public Collection<E> FindAll<E>()
+        {
+            Collection<E> result = new Collection<E>();
+            List<IExtension<T>> items = this.Items;
+
+            lock (this.SyncRoot)
+            {
+                for (int i = 0; i < items.Count; i++)
+                {
+                    IExtension<T> item = items[i];
+                    if (item is E)
+                        result.Add((E)item);
+                }
+            }
+
+            return result;
+        }
+
+        protected override void InsertItem(int index, IExtension<T> item)
+        {
+            if (item == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("item");
+
+            lock (this.SyncRoot)
+            {
+                item.Attach(this.owner);
+                base.InsertItem(index, item);
+            }
+        }
+
+        protected override void RemoveItem(int index)
+        {
+            lock (this.SyncRoot)
+            {
+                this.Items[index].Detach(this.owner);
+                base.RemoveItem(index);
+            }
+        }
+
+        protected override void SetItem(int index, IExtension<T> item)
+        {
+            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidOperationException(SR.GetString(SR.SFxCannotSetExtensionsByIndex)));
+        }
+    }
+}