sharp-chat/SharpChat.Common/Configuration/CachedValue.cs

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2022-08-30 15:05:29 +00:00
using System;
namespace SharpChat.Configuration {
public class CachedValue<T> {
private IConfig Config { get; }
private string Name { get; }
private TimeSpan Lifetime { get; }
private T Fallback { get; }
private object Sync { get; } = new();
private object CurrentValue { get; set; }
private DateTimeOffset LastRead { get; set; }
public T Value {
get {
lock(Sync) {
DateTimeOffset now = DateTimeOffset.Now;
if((now - LastRead) >= Lifetime) {
LastRead = now;
CurrentValue = Config.ReadValue(Name, Fallback);
Logger.Debug($@"Read {Name} ({CurrentValue})");
}
}
return (T)CurrentValue;
}
}
public static implicit operator T(CachedValue<T> val) => val.Value;
public CachedValue(IConfig config, string name, TimeSpan lifetime, T fallback) {
Config = config ?? throw new ArgumentNullException(nameof(config));
Name = name ?? throw new ArgumentNullException(nameof(name));
Lifetime = lifetime;
Fallback = fallback;
if(string.IsNullOrWhiteSpace(name))
throw new ArgumentException(@"Name cannot be empty.", nameof(name));
}
public void Refresh() {
lock(Sync) {
LastRead = DateTimeOffset.MinValue;
}
}
}
}