Initial commit

mod/PLibCore/Detours/DetouredMethod.cs

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2022 Peter Han
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+using System;
+
+namespace PeterHan.PLib.Detours {
+	/// <summary>
+	/// Stores a detoured method, only performing the expensive reflection when the detour is
+	/// first used.
+	/// 
+	/// This class is not thread safe.
+	/// <typeparam name="D">The delegate type to be used to call the detour.</typeparam>
+	/// </summary>
+	public sealed class DetouredMethod<D> where D : Delegate {
+		/// <summary>
+		/// Emulates the ability of Delegate.Invoke to actually call the method.
+		/// </summary>
+		public D Invoke {
+			get {
+				Initialize();
+				return delg;
+			}
+		}
+
+		/// <summary>
+		/// The method name.
+		/// </summary>
+		public string Name { get; }
+
+		/// <summary>
+		/// The delegate method which will be called.
+		/// </summary>
+		private D delg;
+
+		/// <summary>
+		/// The target type.
+		/// </summary>
+		private readonly Type type;
+
+		internal DetouredMethod(Type type, string name) {
+			this.type = type ?? throw new ArgumentNullException(nameof(type));
+			Name = name ?? throw new ArgumentNullException(nameof(name));
+			delg = null;
+		}
+
+		/// <summary>
+		/// Initializes the getter and setter functions immediately if necessary.
+		/// </summary>
+		public void Initialize() {
+			if (delg == null)
+				delg = PDetours.Detour<D>(type, Name);
+		}
+
+		public override string ToString() {
+			return string.Format("LazyDetouredMethod[type={1},name={0}]", Name, type.FullName);
+		}
+	}
+}