sinmai-mods/ImproveLoadTimes/Manager/patch_DataManager.cs

// ReSharper disable CheckNamespace
// ReSharper disable InconsistentNaming
using System.Runtime.Serialization.Formatters.Binary;

namespace Manager;

public class patch_DataManager : DataManager
{
    private const string _cacheFilename = "data_cache.bin";
    private static Dictionary<string, object>? _cache;
    private static bool _cacheBusted;
    
    private static extern bool orig_Deserialize<T>(string filePath, out T dsr) where T : new();
    private static bool Deserialize<T>(string filePath, out T dsr) where T : new()
    {
	    try
	    {
		    _cache ??= LoadCache(_cacheFilename);
	    }
	    catch (Exception e)
	    {
		    System.Console.WriteLine("[ImproveLoadTimes] Could not load data cache: {0}", e);
		    _cache ??= new Dictionary<string, object>();
	    }

        try
        {
	        if (_cache.TryGetValue(filePath, out var dsrObject))
	        {
		        dsr = (T)dsrObject;
		        return true;
	        }

	        if (!orig_Deserialize(filePath, out dsr))
	        {
		        return false;
	        }

	        // ReSharper disable once ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
	        if (filePath == null || dsr == null)
	        {
		        return true;
	        }
	        
	        _cache.Add(filePath, dsr);
	        _cacheBusted = true;

	        return true;
        }
        catch (Exception e)
        {
	        System.Console.WriteLine("[ImproveLoadTimes] [ERROR] Could not load from cache: {0}", e);
	        return orig_Deserialize(filePath, out dsr);
        }
    }

    private extern bool orig_IsLoaded();
    public new bool IsLoaded()
    {
        var loaded = orig_IsLoaded();

        if (!loaded || !_cacheBusted || _cache == null)
        {
            return loaded;
        }
        
        try
        {
	        SaveCache(_cacheFilename, _cache);
        }
        catch (Exception e)
        {
	        System.Console.WriteLine("[ImproveLoadTimes] [ERROR] Could not save to cache: {0}", e);
        }
        
        _cacheBusted = false;

        return true;
    }

    private static Dictionary<string, object> LoadCache(string fileName)
    {
	    if (!File.Exists(fileName))
	    {
		    return new Dictionary<string, object>();
	    }
	    
	    System.Console.WriteLine("[ImproveLoadTimes] Loading data cache...");
	    
	    using var fs = File.OpenRead(fileName);
	    return (Dictionary<string, object>)new BinaryFormatter().Deserialize(fs);
    }
    
    private static void SaveCache(string fileName, Dictionary<string, object> cache)
    {
	    using var fs = File.Open(fileName, FileMode.Create, FileAccess.Write);
	    new BinaryFormatter().Serialize(fs, cache);
    }
}