(dots) code for world serialization and deserialization

Worlds.cs

// src: https://gist.github.com/andrew-raphael-lukasik/66d898be737734f26e607e6526d22901
using IO = System.IO;
using UnityEngine;

using Unity.Entities;
using Unity.Scenes;
using Unity.Entities.Serialization;

public static class Worlds
{

	public static World Create ( string name , WorldSystemFilterFlags filterFlags = WorldSystemFilterFlags.Default , params System.Type[] otherSystems )
	{
		var world = new World( name );
		var systems = DefaultWorldInitialization.GetAllSystems( filterFlags );
		DefaultWorldInitialization.AddSystemsToRootLevelSystemGroups( world , systems );
		if( otherSystems!=null && otherSystems.Length!=0 )
			DefaultWorldInitialization.AddSystemsToRootLevelSystemGroups( world , otherSystems );
		ScriptBehaviourUpdateOrder.AddWorldToCurrentPlayerLoop( world );
		return world;
	}
	
	// Assumes you store Mesh assets in ../Resources/Meshes/ folder
	// Assumes you store Materials assets in ../Resources/Materials/ folder
	public static void Serialize ( World world , string absoluteFilePath )
	{
		var parentDirectoryPath = IO.Path.GetDirectoryName(absoluteFilePath);
		if( !IO.File.Exists(parentDirectoryPath) ) IO.Directory.CreateDirectory(parentDirectoryPath);

		var entityManager = world.EntityManager;
		using( BinaryWriter writer = new StreamBinaryWriter(absoluteFilePath) )
		{
			// write binary file:
			SerializeUtilityHybrid.Serialize( entityManager , writer , out var objRefs );
			Debug.Log($"\t\t\tbinary file saved: \'{absoluteFilePath}\'");
			
			// write managed data (text) file:
			string managedDataFilePath = IO.Path.ChangeExtension(absoluteFilePath,".managed_data");
			if( objRefs!=null )
			{
				var output = new System.Text.StringBuilder();
				foreach( var obj in objRefs.Array )
					output.AppendLine( $"{obj.name}{k_managed_data_separator}{obj.GetType().FullName}" );
				IO.File.WriteAllText( path:managedDataFilePath , contents:output.ToString() );
				Object.DestroyImmediate( objRefs );
				
				Debug.Log($"\t\t\tmanaged data file saved: \'{managedDataFilePath}\'");
			}
			else if( IO.File.Exists(managedDataFilePath) )
			{
				IO.File.Delete(managedDataFilePath);
			}
		}
	}

	// Assumes you store Mesh assets in ../Resources/Meshes/ folder
	// Assumes you store Materials assets in ../Resources/Materials/ folder
	public static void Deserialize ( string absoluteFilePath , World world )
	{
		string directory = IO.Path.GetDirectoryName( absoluteFilePath );
		if( !IO.Directory.Exists(directory) )
		{
			Debug.LogError($"directory does not exists: \'{directory}\'");
			return;
		}

		var objRefs = ScriptableObject.CreateInstance<ReferencedUnityObjects>();
		objRefs.Array = new Object[0];
		{
			string managedDataFilePath = IO.Path.ChangeExtension(absoluteFilePath,".managed_data");
			Debug.Log($"\treading file: '{managedDataFilePath}'");
			string[] lines = IO.File.ReadAllLines( managedDataFilePath );
			for( int lineIndex=0 ; lineIndex<lines.Length ; lineIndex++ )
			{
				string line = lines[lineIndex];
				if( line.Length!=0 )
				{
					string[] nt = line.Split(k_managed_data_separator);
					string obj_name = nt[0];
					string obj_type = nt[1];
					Object obj;
					if( obj_type==typeof(Mesh).FullName )
					{
						string path = $"Meshes/{obj_name}";
						obj = Resources.Load<Mesh>(path);
						if( obj==null ) Debug.LogWarning($"null when reading resource path: '{path}'");
					}
					else if( obj_type==typeof(Material).FullName )
					{
						string path = $"Materials/{obj_name}";
						obj = Resources.Load<Material>(path);
						if( obj==null ) Debug.LogWarning($"null when reading resource path: '{path}'");
					}
					else
					{
						Debug.LogError($"'{obj_type}' is unrecognised type");
						continue;
					}
					System.Array.Resize( ref objRefs.Array , objRefs.Array.Length+1 );
					objRefs.Array[ objRefs.Array.Length-1 ] = obj;
				}
			}
		}
		if( objRefs==null )
		{
			Debug.LogError($"{nameof(objRefs)} is NULL");
			throw new System.Exception();
		}
		
		var entityManager = world.EntityManager;
		using( BinaryReader reader = new StreamBinaryReader(absoluteFilePath) )
			SerializeUtilityHybrid.Deserialize( entityManager , reader , objRefs );
		entityManager.EndExclusiveEntityTransaction();
	}

	const char k_managed_data_separator = '\t';
	
}