jellyfin/Emby.Server.Implementations/IO/LibraryMonitor.cs
2020-06-05 18:15:56 -06:00

548 lines
18 KiB
C#

#pragma warning disable CS1591
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Plugins;
using MediaBrowser.Model.IO;
using Emby.Server.Implementations.Library;
using Microsoft.Extensions.Logging;
namespace Emby.Server.Implementations.IO
{
public class LibraryMonitor : ILibraryMonitor
{
private readonly ILogger<LibraryMonitor> _logger;
private readonly ILibraryManager _libraryManager;
private readonly IServerConfigurationManager _configurationManager;
private readonly IFileSystem _fileSystem;
/// <summary>
/// The file system watchers.
/// </summary>
private readonly ConcurrentDictionary<string, FileSystemWatcher> _fileSystemWatchers = new ConcurrentDictionary<string, FileSystemWatcher>(StringComparer.OrdinalIgnoreCase);
/// <summary>
/// The affected paths.
/// </summary>
private readonly List<FileRefresher> _activeRefreshers = new List<FileRefresher>();
/// <summary>
/// A dynamic list of paths that should be ignored. Added to during our own file system modifications.
/// </summary>
private readonly ConcurrentDictionary<string, string> _tempIgnoredPaths = new ConcurrentDictionary<string, string>(StringComparer.OrdinalIgnoreCase);
/// <summary>
/// Add the path to our temporary ignore list. Use when writing to a path within our listening scope.
/// </summary>
/// <param name="path">The path.</param>
private void TemporarilyIgnore(string path)
{
_tempIgnoredPaths[path] = path;
}
public void ReportFileSystemChangeBeginning(string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(nameof(path));
}
TemporarilyIgnore(path);
}
public bool IsPathLocked(string path)
{
// This method is not used by the core but it used by auto-organize
var lockedPaths = _tempIgnoredPaths.Keys.ToList();
return lockedPaths.Any(i => _fileSystem.AreEqual(i, path) || _fileSystem.ContainsSubPath(i, path));
}
public async void ReportFileSystemChangeComplete(string path, bool refreshPath)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(nameof(path));
}
// This is an arbitrary amount of time, but delay it because file system writes often trigger events long after the file was actually written to.
// Seeing long delays in some situations, especially over the network, sometimes up to 45 seconds
// But if we make this delay too high, we risk missing legitimate changes, such as user adding a new file, or hand-editing metadata
await Task.Delay(45000).ConfigureAwait(false);
_tempIgnoredPaths.TryRemove(path, out var val);
if (refreshPath)
{
try
{
ReportFileSystemChanged(path);
}
catch (Exception ex)
{
_logger.LogError(ex, "Error in ReportFileSystemChanged for {path}", path);
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="LibraryMonitor" /> class.
/// </summary>
public LibraryMonitor(
ILogger<LibraryMonitor> logger,
ILibraryManager libraryManager,
IServerConfigurationManager configurationManager,
IFileSystem fileSystem)
{
_libraryManager = libraryManager;
_logger = logger;
_configurationManager = configurationManager;
_fileSystem = fileSystem;
}
private bool IsLibraryMonitorEnabled(BaseItem item)
{
if (item is BasePluginFolder)
{
return false;
}
var options = _libraryManager.GetLibraryOptions(item);
if (options != null)
{
return options.EnableRealtimeMonitor;
}
return false;
}
public void Start()
{
_libraryManager.ItemAdded += OnLibraryManagerItemAdded;
_libraryManager.ItemRemoved += OnLibraryManagerItemRemoved;
var pathsToWatch = new List<string>();
var paths = _libraryManager
.RootFolder
.Children
.Where(IsLibraryMonitorEnabled)
.OfType<Folder>()
.SelectMany(f => f.PhysicalLocations)
.Distinct(StringComparer.OrdinalIgnoreCase)
.OrderBy(i => i)
.ToList();
foreach (var path in paths)
{
if (!ContainsParentFolder(pathsToWatch, path))
{
pathsToWatch.Add(path);
}
}
foreach (var path in pathsToWatch)
{
StartWatchingPath(path);
}
}
private void StartWatching(BaseItem item)
{
if (IsLibraryMonitorEnabled(item))
{
StartWatchingPath(item.Path);
}
}
/// <summary>
/// Handles the ItemRemoved event of the LibraryManager control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="ItemChangeEventArgs"/> instance containing the event data.</param>
private void OnLibraryManagerItemRemoved(object sender, ItemChangeEventArgs e)
{
if (e.Parent is AggregateFolder)
{
StopWatchingPath(e.Item.Path);
}
}
/// <summary>
/// Handles the ItemAdded event of the LibraryManager control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="ItemChangeEventArgs"/> instance containing the event data.</param>
private void OnLibraryManagerItemAdded(object sender, ItemChangeEventArgs e)
{
if (e.Parent is AggregateFolder)
{
StartWatching(e.Item);
}
}
/// <summary>
/// Examine a list of strings assumed to be file paths to see if it contains a parent of
/// the provided path.
/// </summary>
/// <param name="lst">The LST.</param>
/// <param name="path">The path.</param>
/// <returns><c>true</c> if [contains parent folder] [the specified LST]; otherwise, <c>false</c>.</returns>
/// <exception cref="ArgumentNullException">path</exception>
private static bool ContainsParentFolder(IEnumerable<string> lst, string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(nameof(path));
}
path = path.TrimEnd(Path.DirectorySeparatorChar);
return lst.Any(str =>
{
// this should be a little quicker than examining each actual parent folder...
var compare = str.TrimEnd(Path.DirectorySeparatorChar);
return path.Equals(compare, StringComparison.OrdinalIgnoreCase) || (path.StartsWith(compare, StringComparison.OrdinalIgnoreCase) && path[compare.Length] == Path.DirectorySeparatorChar);
});
}
/// <summary>
/// Starts the watching path.
/// </summary>
/// <param name="path">The path.</param>
private void StartWatchingPath(string path)
{
if (!Directory.Exists(path))
{
// Seeing a crash in the mono runtime due to an exception being thrown on a different thread
_logger.LogInformation("Skipping realtime monitor for {Path} because the path does not exist", path);
return;
}
// Already being watched
if (_fileSystemWatchers.ContainsKey(path))
{
return;
}
// Creating a FileSystemWatcher over the LAN can take hundreds of milliseconds, so wrap it in a Task to do them all in parallel
Task.Run(() =>
{
try
{
var newWatcher = new FileSystemWatcher(path, "*")
{
IncludeSubdirectories = true,
InternalBufferSize = 65536,
NotifyFilter = NotifyFilters.CreationTime |
NotifyFilters.DirectoryName |
NotifyFilters.FileName |
NotifyFilters.LastWrite |
NotifyFilters.Size |
NotifyFilters.Attributes
};
newWatcher.Created += OnWatcherChanged;
newWatcher.Deleted += OnWatcherChanged;
newWatcher.Renamed += OnWatcherChanged;
newWatcher.Changed += OnWatcherChanged;
newWatcher.Error += OnWatcherError;
if (_fileSystemWatchers.TryAdd(path, newWatcher))
{
newWatcher.EnableRaisingEvents = true;
_logger.LogInformation("Watching directory " + path);
}
else
{
DisposeWatcher(newWatcher, false);
}
}
catch (Exception ex)
{
_logger.LogError(ex, "Error watching path: {path}", path);
}
});
}
/// <summary>
/// Stops the watching path.
/// </summary>
/// <param name="path">The path.</param>
private void StopWatchingPath(string path)
{
if (_fileSystemWatchers.TryGetValue(path, out var watcher))
{
DisposeWatcher(watcher, true);
}
}
/// <summary>
/// Disposes the watcher.
/// </summary>
private void DisposeWatcher(FileSystemWatcher watcher, bool removeFromList)
{
try
{
using (watcher)
{
_logger.LogInformation("Stopping directory watching for path {Path}", watcher.Path);
watcher.Created -= OnWatcherChanged;
watcher.Deleted -= OnWatcherChanged;
watcher.Renamed -= OnWatcherChanged;
watcher.Changed -= OnWatcherChanged;
watcher.Error -= OnWatcherError;
watcher.EnableRaisingEvents = false;
}
}
finally
{
if (removeFromList)
{
RemoveWatcherFromList(watcher);
}
}
}
/// <summary>
/// Removes the watcher from list.
/// </summary>
/// <param name="watcher">The watcher.</param>
private void RemoveWatcherFromList(FileSystemWatcher watcher)
{
_fileSystemWatchers.TryRemove(watcher.Path, out _);
}
/// <summary>
/// Handles the Error event of the watcher control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="ErrorEventArgs" /> instance containing the event data.</param>
private void OnWatcherError(object sender, ErrorEventArgs e)
{
var ex = e.GetException();
var dw = (FileSystemWatcher)sender;
_logger.LogError(ex, "Error in Directory watcher for: {Path}", dw.Path);
DisposeWatcher(dw, true);
}
/// <summary>
/// Handles the Changed event of the watcher control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="FileSystemEventArgs" /> instance containing the event data.</param>
private void OnWatcherChanged(object sender, FileSystemEventArgs e)
{
try
{
ReportFileSystemChanged(e.FullPath);
}
catch (Exception ex)
{
_logger.LogError(ex, "Exception in ReportFileSystemChanged. Path: {FullPath}", e.FullPath);
}
}
public void ReportFileSystemChanged(string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(nameof(path));
}
var monitorPath = !IgnorePatterns.ShouldIgnore(path);
// Ignore certain files
var tempIgnorePaths = _tempIgnoredPaths.Keys.ToList();
// If the parent of an ignored path has a change event, ignore that too
if (tempIgnorePaths.Any(i =>
{
if (_fileSystem.AreEqual(i, path))
{
_logger.LogDebug("Ignoring change to {Path}", path);
return true;
}
if (_fileSystem.ContainsSubPath(i, path))
{
_logger.LogDebug("Ignoring change to {Path}", path);
return true;
}
// Go up a level
var parent = Path.GetDirectoryName(i);
if (!string.IsNullOrEmpty(parent) && _fileSystem.AreEqual(parent, path))
{
_logger.LogDebug("Ignoring change to {Path}", path);
return true;
}
return false;
}))
{
monitorPath = false;
}
if (monitorPath)
{
// Avoid implicitly captured closure
CreateRefresher(path);
}
}
private void CreateRefresher(string path)
{
var parentPath = Path.GetDirectoryName(path);
lock (_activeRefreshers)
{
foreach (var refresher in _activeRefreshers)
{
// Path is already being refreshed
if (_fileSystem.AreEqual(path, refresher.Path))
{
refresher.RestartTimer();
return;
}
// Parent folder is already being refreshed
if (_fileSystem.ContainsSubPath(refresher.Path, path))
{
refresher.AddPath(path);
return;
}
// New path is a parent
if (_fileSystem.ContainsSubPath(path, refresher.Path))
{
refresher.ResetPath(path, null);
return;
}
// They are siblings. Rebase the refresher to the parent folder.
if (string.Equals(parentPath, Path.GetDirectoryName(refresher.Path), StringComparison.Ordinal))
{
refresher.ResetPath(parentPath, path);
return;
}
}
var newRefresher = new FileRefresher(path, _configurationManager, _libraryManager, _logger);
newRefresher.Completed += NewRefresher_Completed;
_activeRefreshers.Add(newRefresher);
}
}
private void NewRefresher_Completed(object sender, EventArgs e)
{
var refresher = (FileRefresher)sender;
DisposeRefresher(refresher);
}
/// <summary>
/// Stops this instance.
/// </summary>
public void Stop()
{
_libraryManager.ItemAdded -= OnLibraryManagerItemAdded;
_libraryManager.ItemRemoved -= OnLibraryManagerItemRemoved;
foreach (var watcher in _fileSystemWatchers.Values.ToList())
{
DisposeWatcher(watcher, false);
}
_fileSystemWatchers.Clear();
DisposeRefreshers();
}
private void DisposeRefresher(FileRefresher refresher)
{
lock (_activeRefreshers)
{
refresher.Dispose();
_activeRefreshers.Remove(refresher);
}
}
private void DisposeRefreshers()
{
lock (_activeRefreshers)
{
foreach (var refresher in _activeRefreshers.ToList())
{
refresher.Dispose();
}
_activeRefreshers.Clear();
}
}
private bool _disposed = false;
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
/// <summary>
/// Releases unmanaged and - optionally - managed resources.
/// </summary>
/// <param name="disposing"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
protected virtual void Dispose(bool disposing)
{
if (_disposed)
{
return;
}
if (disposing)
{
Stop();
}
_disposed = true;
}
}
public class LibraryMonitorStartup : IServerEntryPoint
{
private readonly ILibraryMonitor _monitor;
public LibraryMonitorStartup(ILibraryMonitor monitor)
{
_monitor = monitor;
}
public Task RunAsync()
{
_monitor.Start();
return Task.CompletedTask;
}
public void Dispose()
{
}
}
}