Sicherung

Config.Net/Core/Box/CollectionResultBox.cs

@@ -0,0 +1,109 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Config.Net.Core.Box
+{
+   class CollectionResultBox : ResultBox
+   {
+      private readonly ResultBox _elementResultBox;
+      private string? _basePath;
+      private DynamicReader? _reader;
+
+      public CollectionResultBox(string name, ResultBox elementBox) : base(name, elementBox.ResultType, null)
+      {
+         _elementResultBox = elementBox;
+      }
+
+      public ResultBox ElementResultBox => _elementResultBox;
+
+      public bool IsInitialised { get; private set; }
+
+      public IEnumerable? CollectionInstance { get; private set; }
+
+      public void Initialise(string? basePath, int length, DynamicReader reader)
+      {
+         _basePath = basePath;
+         _reader = reader;
+
+         CollectionInstance = CreateGenericEnumerable(length);
+
+         IsInitialised = true;
+      }
+
+      private IEnumerable? CreateGenericEnumerable(int count)
+      {
+         Type t = typeof(DynamicEnumerable<>);
+         t = t.MakeGenericType(ResultType);
+
+         IEnumerable? instance = (IEnumerable?)Activator.CreateInstance(t, count, this);
+
+         return instance;
+      }
+
+      private object? ReadAt(int index)
+      {
+         return _reader?.Read(ElementResultBox, index);
+      }
+
+      private class DynamicEnumerable<T> : IEnumerable<T>
+      {
+         private readonly int _count;
+         private readonly CollectionResultBox _parent;
+
+         public DynamicEnumerable(int count, CollectionResultBox parent)
+         {
+            _count = count;
+            _parent = parent;
+         }
+
+         public IEnumerator<T> GetEnumerator()
+         {
+            return new DynamicEnumerator<T>(_count, _parent);
+         }
+
+         IEnumerator IEnumerable.GetEnumerator()
+         {
+            return new DynamicEnumerator<T>(_count, _parent);
+         }
+      }
+
+      private class DynamicEnumerator<T> : IEnumerator<T>
+      {
+         private int _index = -1;
+         private readonly int _count;
+         private readonly CollectionResultBox _parent;
+         private T? _current;
+
+         public DynamicEnumerator(int count, CollectionResultBox parent)
+         {
+            _count = count;
+            _parent = parent;
+         }
+
+#pragma warning disable CS8603 // Possible null reference return.
+         public T Current => _current ?? default(T);
+
+         object IEnumerator.Current => _current;
+#pragma warning restore CS8603 // Possible null reference return.
+
+         public void Dispose()
+         {
+         }
+
+         public bool MoveNext()
+         {
+            _index += 1;
+
+            _current = (T?)_parent.ReadAt(_index);
+
+            return _index < _count;
+         }
+
+         public void Reset()
+         {
+            _index = -1;
+         }
+      }
+   }
+}