jellyfin/Emby.Server.Implementations/AppBase/ConfigurationHelper.cs
2022-12-05 15:00:20 +01:00

63 lines
2.3 KiB
C#

using System;
using System.IO;
using MediaBrowser.Model.Serialization;
namespace Emby.Server.Implementations.AppBase
{
/// <summary>
/// Class ConfigurationHelper.
/// </summary>
public static class ConfigurationHelper
{
/// <summary>
/// Reads an xml configuration file from the file system
/// It will immediately re-serialize and save if new serialization data is available due to property changes.
/// </summary>
/// <param name="type">The type.</param>
/// <param name="path">The path.</param>
/// <param name="xmlSerializer">The XML serializer.</param>
/// <returns>System.Object.</returns>
public static object GetXmlConfiguration(Type type, string path, IXmlSerializer xmlSerializer)
{
object configuration;
byte[]? buffer = null;
// Use try/catch to avoid the extra file system lookup using File.Exists
try
{
buffer = File.ReadAllBytes(path);
configuration = xmlSerializer.DeserializeFromBytes(type, buffer);
}
catch (Exception)
{
// Note: CreateInstance returns null for Nullable<T>, e.g. CreateInstance(typeof(int?)) returns null.
configuration = Activator.CreateInstance(type)!;
}
using var stream = new MemoryStream(buffer?.Length ?? 0);
xmlSerializer.SerializeToStream(configuration, stream);
// Take the object we just got and serialize it back to bytes
Span<byte> newBytes = stream.GetBuffer().AsSpan(0, (int)stream.Length);
// If the file didn't exist before, or if something has changed, re-save
if (buffer is null || !newBytes.SequenceEqual(buffer))
{
var directory = Path.GetDirectoryName(path) ?? throw new ArgumentException($"Provided path ({path}) is not valid.", nameof(path));
Directory.CreateDirectory(directory);
// Save it after load in case we got new items
using (var fs = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.None))
{
fs.Write(newBytes);
}
}
return configuration;
}
}
}