using MediaBrowser.Common.IO;
using MediaBrowser.Common.ScheduledTasks;
using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Model.Logging;
using MediaBrowser.Server.Implementations.ScheduledTasks;
using Microsoft.Win32;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
namespace MediaBrowser.Server.Implementations.IO
{
public class LibraryMonitor : ILibraryMonitor
{
///
/// The file system watchers
///
private readonly ConcurrentDictionary _fileSystemWatchers = new ConcurrentDictionary(StringComparer.OrdinalIgnoreCase);
///
/// The update timer
///
private Timer _updateTimer;
///
/// The affected paths
///
private readonly ConcurrentDictionary _affectedPaths = new ConcurrentDictionary();
///
/// A dynamic list of paths that should be ignored. Added to during our own file sytem modifications.
///
private readonly ConcurrentDictionary _tempIgnoredPaths = new ConcurrentDictionary(StringComparer.OrdinalIgnoreCase);
///
/// Any file name ending in any of these will be ignored by the watchers
///
private readonly IReadOnlyList _alwaysIgnoreFiles = new List
{
"thumbs.db",
"small.jpg",
"albumart.jpg",
// WMC temp recording directories that will constantly be written to
"TempRec",
"TempSBE"
};
///
/// The timer lock
///
private readonly object _timerLock = new object();
///
/// Add the path to our temporary ignore list. Use when writing to a path within our listening scope.
///
/// The path.
private void TemporarilyIgnore(string path)
{
_tempIgnoredPaths[path] = path;
}
public void ReportFileSystemChangeBeginning(string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("path");
}
TemporarilyIgnore(path);
}
public async void ReportFileSystemChangeComplete(string path, bool refreshPath)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("path");
}
// This is an arbitraty amount of time, but delay it because file system writes often trigger events after RemoveTempIgnore has been called.
// Seeing long delays in some situations, especially over the network.
// Seeing delays up to 40 seconds, but not going to ignore changes for that long.
await Task.Delay(1500).ConfigureAwait(false);
string val;
_tempIgnoredPaths.TryRemove(path, out val);
if (refreshPath)
{
ReportFileSystemChanged(path);
}
}
///
/// Gets or sets the logger.
///
/// The logger.
private ILogger Logger { get; set; }
///
/// Gets or sets the task manager.
///
/// The task manager.
private ITaskManager TaskManager { get; set; }
private ILibraryManager LibraryManager { get; set; }
private IServerConfigurationManager ConfigurationManager { get; set; }
private readonly IFileSystem _fileSystem;
///
/// Initializes a new instance of the class.
///
public LibraryMonitor(ILogManager logManager, ITaskManager taskManager, ILibraryManager libraryManager, IServerConfigurationManager configurationManager, IFileSystem fileSystem)
{
if (taskManager == null)
{
throw new ArgumentNullException("taskManager");
}
LibraryManager = libraryManager;
TaskManager = taskManager;
Logger = logManager.GetLogger(GetType().Name);
ConfigurationManager = configurationManager;
_fileSystem = fileSystem;
SystemEvents.PowerModeChanged += SystemEvents_PowerModeChanged;
}
///
/// Handles the PowerModeChanged event of the SystemEvents control.
///
/// The source of the event.
/// The instance containing the event data.
void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
Restart();
}
private void Restart()
{
Stop();
Start();
}
public void Start()
{
if (ConfigurationManager.Configuration.EnableRealtimeMonitor)
{
StartInternal();
}
}
///
/// Starts this instance.
///
private void StartInternal()
{
LibraryManager.ItemAdded += LibraryManager_ItemAdded;
LibraryManager.ItemRemoved += LibraryManager_ItemRemoved;
var pathsToWatch = new List { LibraryManager.RootFolder.Path };
var paths = LibraryManager
.RootFolder
.Children
.OfType()
.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);
}
}
///
/// Handles the ItemRemoved event of the LibraryManager control.
///
/// The source of the event.
/// The instance containing the event data.
void LibraryManager_ItemRemoved(object sender, ItemChangeEventArgs e)
{
if (e.Item.Parent is AggregateFolder)
{
StopWatchingPath(e.Item.Path);
}
}
///
/// Handles the ItemAdded event of the LibraryManager control.
///
/// The source of the event.
/// The instance containing the event data.
void LibraryManager_ItemAdded(object sender, ItemChangeEventArgs e)
{
if (e.Item.Parent is AggregateFolder)
{
StartWatchingPath(e.Item.Path);
}
}
///
/// Examine a list of strings assumed to be file paths to see if it contains a parent of
/// the provided path.
///
/// The LST.
/// The path.
/// true if [contains parent folder] [the specified LST]; otherwise, false.
/// path
private static bool ContainsParentFolder(IEnumerable lst, string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("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));
});
}
///
/// Starts the watching path.
///
/// The path.
private void StartWatchingPath(string path)
{
// 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(() =>
{
var newWatcher = new FileSystemWatcher(path, "*") { IncludeSubdirectories = true, InternalBufferSize = 32767 };
newWatcher.Created += watcher_Changed;
newWatcher.Deleted += watcher_Changed;
newWatcher.Renamed += watcher_Changed;
newWatcher.Changed += watcher_Changed;
newWatcher.Error += watcher_Error;
try
{
if (_fileSystemWatchers.TryAdd(path, newWatcher))
{
newWatcher.EnableRaisingEvents = true;
Logger.Info("Watching directory " + path);
}
else
{
Logger.Info("Unable to add directory watcher for {0}. It already exists in the dictionary." + path);
newWatcher.Dispose();
}
}
catch (IOException ex)
{
Logger.ErrorException("Error watching path: {0}", ex, path);
}
catch (PlatformNotSupportedException ex)
{
Logger.ErrorException("Error watching path: {0}", ex, path);
}
});
}
///
/// Stops the watching path.
///
/// The path.
private void StopWatchingPath(string path)
{
FileSystemWatcher watcher;
if (_fileSystemWatchers.TryGetValue(path, out watcher))
{
DisposeWatcher(watcher);
}
}
///
/// Disposes the watcher.
///
/// The watcher.
private void DisposeWatcher(FileSystemWatcher watcher)
{
Logger.Info("Stopping directory watching for path {0}", watcher.Path);
watcher.EnableRaisingEvents = false;
watcher.Dispose();
RemoveWatcherFromList(watcher);
}
///
/// Removes the watcher from list.
///
/// The watcher.
private void RemoveWatcherFromList(FileSystemWatcher watcher)
{
FileSystemWatcher removed;
_fileSystemWatchers.TryRemove(watcher.Path, out removed);
}
///
/// Handles the Error event of the watcher control.
///
/// The source of the event.
/// The instance containing the event data.
void watcher_Error(object sender, ErrorEventArgs e)
{
var ex = e.GetException();
var dw = (FileSystemWatcher)sender;
Logger.ErrorException("Error in Directory watcher for: " + dw.Path, ex);
DisposeWatcher(dw);
}
///
/// Handles the Changed event of the watcher control.
///
/// The source of the event.
/// The instance containing the event data.
void watcher_Changed(object sender, FileSystemEventArgs e)
{
try
{
OnWatcherChanged(e);
}
catch (Exception ex)
{
Logger.ErrorException("Exception in watcher changed. Path: {0}", ex, e.FullPath);
}
}
private void OnWatcherChanged(FileSystemEventArgs e)
{
Logger.Debug("Watcher sees change of type " + e.ChangeType + " to " + e.FullPath);
ReportFileSystemChanged(e.FullPath);
}
public void ReportFileSystemChanged(string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("path");
}
var filename = Path.GetFileName(path);
// Ignore certain files
if (!string.IsNullOrEmpty(filename) && _alwaysIgnoreFiles.Contains(filename, StringComparer.OrdinalIgnoreCase))
{
return;
}
var tempIgnorePaths = _tempIgnoredPaths.Keys.ToList();
// If the parent of an ignored path has a change event, ignore that too
if (tempIgnorePaths.Any(i =>
{
if (string.Equals(i, path, StringComparison.OrdinalIgnoreCase))
{
Logger.Debug("Ignoring change to {0}", path);
return true;
}
if (_fileSystem.ContainsSubPath(i, path))
{
Logger.Debug("Ignoring change to {0}", path);
return true;
}
// Go up a level
var parent = Path.GetDirectoryName(i);
if (!string.IsNullOrEmpty(parent))
{
if (string.Equals(parent, path, StringComparison.OrdinalIgnoreCase))
{
Logger.Debug("Ignoring change to {0}", path);
return true;
}
// Go up another level
parent = Path.GetDirectoryName(i);
if (string.Equals(parent, path, StringComparison.OrdinalIgnoreCase))
{
Logger.Debug("Ignoring change to {0}", path);
return true;
}
}
return false;
}))
{
return;
}
// Avoid implicitly captured closure
var affectedPath = path;
_affectedPaths.AddOrUpdate(path, path, (key, oldValue) => affectedPath);
lock (_timerLock)
{
if (_updateTimer == null)
{
_updateTimer = new Timer(TimerStopped, null, TimeSpan.FromSeconds(ConfigurationManager.Configuration.RealtimeWatcherDelay), TimeSpan.FromMilliseconds(-1));
}
else
{
_updateTimer.Change(TimeSpan.FromSeconds(ConfigurationManager.Configuration.RealtimeWatcherDelay), TimeSpan.FromMilliseconds(-1));
}
}
}
///
/// Timers the stopped.
///
/// The state info.
private async void TimerStopped(object stateInfo)
{
Logger.Debug("Timer stopped.");
DisposeTimer();
var paths = _affectedPaths.Keys.ToList();
_affectedPaths.Clear();
await ProcessPathChanges(paths).ConfigureAwait(false);
}
private void DisposeTimer()
{
lock (_timerLock)
{
if (_updateTimer != null)
{
_updateTimer.Dispose();
_updateTimer = null;
}
}
}
///
/// Processes the path changes.
///
/// The paths.
/// Task.
private async Task ProcessPathChanges(List paths)
{
var itemsToRefresh = paths.Select(Path.GetDirectoryName)
.Select(GetAffectedBaseItem)
.Where(item => item != null)
.Distinct()
.ToList();
foreach (var p in paths) Logger.Info(p + " reports change.");
// If the root folder changed, run the library task so the user can see it
if (itemsToRefresh.Any(i => i is AggregateFolder))
{
TaskManager.CancelIfRunningAndQueue();
return;
}
foreach (var item in itemsToRefresh)
{
Logger.Info(item.Name + " (" + item.Path + ") will be refreshed.");
try
{
await item.ChangedExternally().ConfigureAwait(false);
}
catch (IOException ex)
{
// For now swallow and log.
// Research item: If an IOException occurs, the item may be in a disconnected state (media unavailable)
// Should we remove it from it's parent?
Logger.ErrorException("Error refreshing {0}", ex, item.Name);
}
catch (Exception ex)
{
Logger.ErrorException("Error refreshing {0}", ex, item.Name);
}
}
}
///
/// Gets the affected base item.
///
/// The path.
/// BaseItem.
private BaseItem GetAffectedBaseItem(string path)
{
BaseItem item = null;
while (item == null && !string.IsNullOrEmpty(path))
{
item = LibraryManager.RootFolder.FindByPath(path);
path = Path.GetDirectoryName(path);
}
if (item != null)
{
// If the item has been deleted find the first valid parent that still exists
while (!Directory.Exists(item.Path) && !File.Exists(item.Path))
{
item = item.Parent;
if (item == null)
{
break;
}
}
}
return item;
}
///
/// Stops this instance.
///
public void Stop()
{
LibraryManager.ItemAdded -= LibraryManager_ItemAdded;
LibraryManager.ItemRemoved -= LibraryManager_ItemRemoved;
foreach (var watcher in _fileSystemWatchers.Values.ToList())
{
watcher.Changed -= watcher_Changed;
watcher.EnableRaisingEvents = false;
watcher.Dispose();
}
DisposeTimer();
_fileSystemWatchers.Clear();
_affectedPaths.Clear();
}
///
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
///
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
///
/// Releases unmanaged and - optionally - managed resources.
///
/// true to release both managed and unmanaged resources; false to release only unmanaged resources.
protected virtual void Dispose(bool dispose)
{
if (dispose)
{
Stop();
}
}
}
}