jellyfin/Emby.Server.Implementations/LiveTv/EmbyTV/ItemDataProvider.cs
2022-12-05 15:01:13 +01:00

164 lines
4.5 KiB
C#

#pragma warning disable CS1591
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Linq;
using System.Text.Json;
using Jellyfin.Extensions.Json;
using Microsoft.Extensions.Logging;
namespace Emby.Server.Implementations.LiveTv.EmbyTV
{
public class ItemDataProvider<T>
where T : class
{
private readonly string _dataPath;
private readonly object _fileDataLock = new object();
private readonly JsonSerializerOptions _jsonOptions = JsonDefaults.Options;
private T[]? _items;
public ItemDataProvider(
ILogger logger,
string dataPath,
Func<T, T, bool> equalityComparer)
{
Logger = logger;
_dataPath = dataPath;
EqualityComparer = equalityComparer;
}
protected ILogger Logger { get; }
protected Func<T, T, bool> EqualityComparer { get; }
[MemberNotNull(nameof(_items))]
private void EnsureLoaded()
{
if (_items is not null)
{
return;
}
if (File.Exists(_dataPath))
{
Logger.LogInformation("Loading live tv data from {Path}", _dataPath);
try
{
var bytes = File.ReadAllBytes(_dataPath);
_items = JsonSerializer.Deserialize<T[]>(bytes, _jsonOptions);
if (_items is null)
{
Logger.LogError("Error deserializing {Path}, data was null", _dataPath);
_items = Array.Empty<T>();
}
return;
}
catch (JsonException ex)
{
Logger.LogError(ex, "Error deserializing {Path}", _dataPath);
}
}
_items = Array.Empty<T>();
}
private void SaveList()
{
Directory.CreateDirectory(Path.GetDirectoryName(_dataPath) ?? throw new ArgumentException("Path can't be a root directory.", nameof(_dataPath)));
var jsonString = JsonSerializer.Serialize(_items, _jsonOptions);
File.WriteAllText(_dataPath, jsonString);
}
public IReadOnlyList<T> GetAll()
{
lock (_fileDataLock)
{
EnsureLoaded();
return (T[])_items.Clone();
}
}
public virtual void Update(T item)
{
ArgumentNullException.ThrowIfNull(item);
lock (_fileDataLock)
{
EnsureLoaded();
var index = Array.FindIndex(_items, i => EqualityComparer(i, item));
if (index == -1)
{
throw new ArgumentException("item not found");
}
_items[index] = item;
SaveList();
}
}
public virtual void Add(T item)
{
ArgumentNullException.ThrowIfNull(item);
lock (_fileDataLock)
{
EnsureLoaded();
if (_items.Any(i => EqualityComparer(i, item)))
{
throw new ArgumentException("item already exists", nameof(item));
}
int oldLen = _items.Length;
var newList = new T[oldLen + 1];
_items.CopyTo(newList, 0);
newList[oldLen] = item;
_items = newList;
SaveList();
}
}
public virtual void AddOrUpdate(T item)
{
lock (_fileDataLock)
{
EnsureLoaded();
int index = Array.FindIndex(_items, i => EqualityComparer(i, item));
if (index == -1)
{
int oldLen = _items.Length;
var newList = new T[oldLen + 1];
_items.CopyTo(newList, 0);
newList[oldLen] = item;
_items = newList;
}
else
{
_items[index] = item;
}
SaveList();
}
}
public virtual void Delete(T item)
{
lock (_fileDataLock)
{
EnsureLoaded();
_items = _items.Where(i => !EqualityComparer(i, item)).ToArray();
SaveList();
}
}
}
}