// Licensed to the .NET Foundation under one or more agreements. // The .NET Foundation licenses this file to you under the MIT license. // See the LICENSE file in the project root for more information. /*============================================================ ** ** ** ** ** ** Purpose: List for exceptions. ** ** ===========================================================*/ using System.Diagnostics.Contracts; namespace System.Collections { /// This is a simple implementation of IDictionary using a singly linked list. This /// will be smaller and faster than a Hashtable if the number of elements is 10 or less. /// This should not be used if performance is important for large numbers of elements. [Serializable] internal class ListDictionaryInternal: IDictionary { DictionaryNode head; int version; int count; [NonSerialized] private Object _syncRoot; public ListDictionaryInternal() { } public Object this[Object key] { get { if (key == null) { throw new ArgumentNullException(nameof(key), Environment.GetResourceString("ArgumentNull_Key")); } Contract.EndContractBlock(); DictionaryNode node = head; while (node != null) { if ( node.key.Equals(key) ) { return node.value; } node = node.next; } return null; } set { if (key == null) { throw new ArgumentNullException(nameof(key), Environment.GetResourceString("ArgumentNull_Key")); } Contract.EndContractBlock(); version++; DictionaryNode last = null; DictionaryNode node; for (node = head; node != null; node = node.next) { if( node.key.Equals(key) ) { break; } last = node; } if (node != null) { // Found it node.value = value; return; } // Not found, so add a new one DictionaryNode newNode = new DictionaryNode(); newNode.key = key; newNode.value = value; if (last != null) { last.next = newNode; } else { head = newNode; } count++; } } public int Count { get { return count; } } public ICollection Keys { get { return new NodeKeyValueCollection(this, true); } } public bool IsReadOnly { get { return false; } } public bool IsFixedSize { get { return false; } } public bool IsSynchronized { get { return false; } } public Object SyncRoot { get { if( _syncRoot == null) { System.Threading.Interlocked.CompareExchange(ref _syncRoot, new Object(), null); } return _syncRoot; } } public ICollection Values { get { return new NodeKeyValueCollection(this, false); } } public void Add(Object key, Object value) { if (key == null) { throw new ArgumentNullException(nameof(key), Environment.GetResourceString("ArgumentNull_Key")); } Contract.EndContractBlock(); version++; DictionaryNode last = null; DictionaryNode node; for (node = head; node != null; node = node.next) { if (node.key.Equals(key)) { throw new ArgumentException(Environment.GetResourceString("Argument_AddingDuplicate__", node.key, key)); } last = node; } if (node != null) { // Found it node.value = value; return; } // Not found, so add a new one DictionaryNode newNode = new DictionaryNode(); newNode.key = key; newNode.value = value; if (last != null) { last.next = newNode; } else { head = newNode; } count++; } public void Clear() { count = 0; head = null; version++; } public bool Contains(Object key) { if (key == null) { throw new ArgumentNullException(nameof(key), Environment.GetResourceString("ArgumentNull_Key")); } Contract.EndContractBlock(); for (DictionaryNode node = head; node != null; node = node.next) { if (node.key.Equals(key)) { return true; } } return false; } public void CopyTo(Array array, int index) { if (array==null) throw new ArgumentNullException(nameof(array)); if (array.Rank != 1) throw new ArgumentException(Environment.GetResourceString("Arg_RankMultiDimNotSupported")); if (index < 0) throw new ArgumentOutOfRangeException(nameof(index), Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum")); if ( array.Length - index < this.Count ) throw new ArgumentException( Environment.GetResourceString("ArgumentOutOfRange_Index"), nameof(index)); Contract.EndContractBlock(); for (DictionaryNode node = head; node != null; node = node.next) { array.SetValue(new DictionaryEntry(node.key, node.value), index); index++; } } public IDictionaryEnumerator GetEnumerator() { return new NodeEnumerator(this); } IEnumerator IEnumerable.GetEnumerator() { return new NodeEnumerator(this); } public void Remove(Object key) { if (key == null) { throw new ArgumentNullException(nameof(key), Environment.GetResourceString("ArgumentNull_Key")); } Contract.EndContractBlock(); version++; DictionaryNode last = null; DictionaryNode node; for (node = head; node != null; node = node.next) { if (node.key.Equals(key)) { break; } last = node; } if (node == null) { return; } if (node == head) { head = node.next; } else { last.next = node.next; } count--; } private class NodeEnumerator : IDictionaryEnumerator { ListDictionaryInternal list; DictionaryNode current; int version; bool start; public NodeEnumerator(ListDictionaryInternal list) { this.list = list; version = list.version; start = true; current = null; } public Object Current { get { return Entry; } } public DictionaryEntry Entry { get { if (current == null) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumOpCantHappen")); } return new DictionaryEntry(current.key, current.value); } } public Object Key { get { if (current == null) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumOpCantHappen")); } return current.key; } } public Object Value { get { if (current == null) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumOpCantHappen")); } return current.value; } } public bool MoveNext() { if (version != list.version) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumFailedVersion")); } if (start) { current = list.head; start = false; } else { if( current != null ) { current = current.next; } } return (current != null); } public void Reset() { if (version != list.version) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumFailedVersion")); } start = true; current = null; } } private class NodeKeyValueCollection : ICollection { ListDictionaryInternal list; bool isKeys; public NodeKeyValueCollection(ListDictionaryInternal list, bool isKeys) { this.list = list; this.isKeys = isKeys; } void ICollection.CopyTo(Array array, int index) { if (array==null) throw new ArgumentNullException(nameof(array)); if (array.Rank != 1) throw new ArgumentException(Environment.GetResourceString("Arg_RankMultiDimNotSupported")); if (index < 0) throw new ArgumentOutOfRangeException(nameof(index), Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum")); Contract.EndContractBlock(); if (array.Length - index < list.Count) throw new ArgumentException(Environment.GetResourceString("ArgumentOutOfRange_Index"), nameof(index)); for (DictionaryNode node = list.head; node != null; node = node.next) { array.SetValue(isKeys ? node.key : node.value, index); index++; } } int ICollection.Count { get { int count = 0; for (DictionaryNode node = list.head; node != null; node = node.next) { count++; } return count; } } bool ICollection.IsSynchronized { get { return false; } } Object ICollection.SyncRoot { get { return list.SyncRoot; } } IEnumerator IEnumerable.GetEnumerator() { return new NodeKeyValueEnumerator(list, isKeys); } private class NodeKeyValueEnumerator: IEnumerator { ListDictionaryInternal list; DictionaryNode current; int version; bool isKeys; bool start; public NodeKeyValueEnumerator(ListDictionaryInternal list, bool isKeys) { this.list = list; this.isKeys = isKeys; this.version = list.version; this.start = true; this.current = null; } public Object Current { get { if (current == null) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumOpCantHappen")); } return isKeys ? current.key : current.value; } } public bool MoveNext() { if (version != list.version) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumFailedVersion")); } if (start) { current = list.head; start = false; } else { if( current != null) { current = current.next; } } return (current != null); } public void Reset() { if (version != list.version) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_EnumFailedVersion")); } start = true; current = null; } } } [Serializable] private class DictionaryNode { public Object key; public Object value; public DictionaryNode next; } } }