oni-priority-ux/mod/PLibCore/Detours/LazyDetouredField.cs

94 lines
2.9 KiB
C#

/*
* 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 delegates used to read and write fields or properties. This version is lazy and
/// only calculates the destination when it is first used.
///
/// This class is not thread safe.
/// </summary>
/// <typeparam name="P">The containing type of the field or property.</typeparam>
/// <typeparam name="T">The element type of the field or property.</typeparam>
internal sealed class LazyDetouredField<P, T> : IDetouredField<P, T> {
/// <summary>
/// Invoke to get the field/property value.
/// </summary>
public Func<P, T> Get {
get {
Initialize();
return getter;
}
}
/// <summary>
/// The field name.
/// </summary>
public string Name { get; }
/// <summary>
/// Invoke to set the field/property value.
/// </summary>
public Action<P, T> Set {
get {
Initialize();
return setter;
}
}
/// <summary>
/// The function to get the field value.
/// </summary>
private Func<P, T> getter;
/// <summary>
/// The function to set the field value.
/// </summary>
private Action<P, T> setter;
/// <summary>
/// The target type.
/// </summary>
private readonly Type type;
internal LazyDetouredField(Type type, string name) {
this.type = type ?? throw new ArgumentNullException(nameof(type));
Name = name ?? throw new ArgumentNullException(nameof(name));
getter = null;
setter = null;
}
/// <summary>
/// Initializes the getter and setter functions immediately if necessary.
/// </summary>
public void Initialize() {
if (getter == null && setter == null) {
var dt = PDetours.DetourField<P, T>(Name);
getter = dt.Get;
setter = dt.Set;
}
}
public override string ToString() {
return string.Format("LazyDetouredField[type={1},name={0}]", Name, type.FullName);
}
}
}