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jellyfin/Emby.Server.Implementations/SyncPlay/Group.cs

689 lines
24 KiB

#nullable disable
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Data.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Session;
using MediaBrowser.Controller.SyncPlay;
using MediaBrowser.Controller.SyncPlay.GroupStates;
using MediaBrowser.Controller.SyncPlay.Queue;
using MediaBrowser.Controller.SyncPlay.Requests;
using MediaBrowser.Model.SyncPlay;
using Microsoft.Extensions.Logging;
namespace Emby.Server.Implementations.SyncPlay
{
/// <summary>
/// Class Group.
/// </summary>
/// <remarks>
/// Class is not thread-safe, external locking is required when accessing methods.
/// </remarks>
public class Group : IGroupStateContext
{
/// <summary>
/// The logger.
/// </summary>
private readonly ILogger<Group> _logger;
/// <summary>
/// The logger factory.
/// </summary>
private readonly ILoggerFactory _loggerFactory;
/// <summary>
/// The user manager.
/// </summary>
private readonly IUserManager _userManager;
/// <summary>
/// The session manager.
/// </summary>
private readonly ISessionManager _sessionManager;
/// <summary>
/// The library manager.
/// </summary>
private readonly ILibraryManager _libraryManager;
/// <summary>
/// The participants, or members of the group.
/// </summary>
private readonly Dictionary<string, GroupMember> _participants =
new Dictionary<string, GroupMember>(StringComparer.OrdinalIgnoreCase);
/// <summary>
/// The internal group state.
/// </summary>
private IGroupState _state;
/// <summary>
/// Initializes a new instance of the <see cref="Group" /> class.
/// </summary>
/// <param name="loggerFactory">The logger factory.</param>
/// <param name="userManager">The user manager.</param>
/// <param name="sessionManager">The session manager.</param>
/// <param name="libraryManager">The library manager.</param>
public Group(
ILoggerFactory loggerFactory,
IUserManager userManager,
ISessionManager sessionManager,
ILibraryManager libraryManager)
{
_loggerFactory = loggerFactory;
_userManager = userManager;
_sessionManager = sessionManager;
_libraryManager = libraryManager;
_logger = loggerFactory.CreateLogger<Group>();
_state = new IdleGroupState(loggerFactory);
}
/// <summary>
/// Gets the default ping value used for sessions.
/// </summary>
/// <value>The default ping.</value>
public long DefaultPing { get; } = 500;
/// <summary>
/// Gets the maximum time offset error accepted for dates reported by clients, in milliseconds.
/// </summary>
/// <value>The maximum time offset error.</value>
public long TimeSyncOffset { get; } = 2000;
/// <summary>
/// Gets the maximum offset error accepted for position reported by clients, in milliseconds.
/// </summary>
/// <value>The maximum offset error.</value>
public long MaxPlaybackOffset { get; } = 500;
/// <summary>
/// Gets the group identifier.
/// </summary>
/// <value>The group identifier.</value>
public Guid GroupId { get; } = Guid.NewGuid();
/// <summary>
/// Gets the group name.
/// </summary>
/// <value>The group name.</value>
public string GroupName { get; private set; }
/// <summary>
/// Gets the group identifier.
/// </summary>
/// <value>The group identifier.</value>
public PlayQueueManager PlayQueue { get; } = new PlayQueueManager();
/// <summary>
/// Gets the runtime ticks of current playing item.
/// </summary>
/// <value>The runtime ticks of current playing item.</value>
public long RunTimeTicks { get; private set; }
/// <summary>
/// Gets or sets the position ticks.
/// </summary>
/// <value>The position ticks.</value>
public long PositionTicks { get; set; }
/// <summary>
/// Gets or sets the last activity.
/// </summary>
/// <value>The last activity.</value>
public DateTime LastActivity { get; set; }
/// <summary>
/// Adds the session to the group.
/// </summary>
/// <param name="session">The session.</param>
private void AddSession(SessionInfo session)
{
_participants.TryAdd(
session.Id,
new GroupMember(session)
{
Ping = DefaultPing,
IsBuffering = false
});
}
/// <summary>
/// Removes the session from the group.
/// </summary>
/// <param name="session">The session.</param>
private void RemoveSession(SessionInfo session)
{
_participants.Remove(session.Id);
}
/// <summary>
/// Filters sessions of this group.
/// </summary>
/// <param name="fromId">The current session identifier.</param>
/// <param name="type">The filtering type.</param>
/// <returns>The list of sessions matching the filter.</returns>
private IEnumerable<string> FilterSessions(string fromId, SyncPlayBroadcastType type)
{
return type switch
{
SyncPlayBroadcastType.CurrentSession => new string[] { fromId },
SyncPlayBroadcastType.AllGroup => _participants
.Values
.Select(member => member.SessionId),
SyncPlayBroadcastType.AllExceptCurrentSession => _participants
.Values
.Select(member => member.SessionId)
.Where(sessionId => !sessionId.Equals(fromId, StringComparison.OrdinalIgnoreCase)),
SyncPlayBroadcastType.AllReady => _participants
.Values
.Where(member => !member.IsBuffering)
.Select(member => member.SessionId),
_ => Enumerable.Empty<string>()
};
}
/// <summary>
/// Checks if a given user can access all items of a given queue, that is,
/// the user has the required minimum parental access and has access to all required folders.
/// </summary>
/// <param name="user">The user.</param>
/// <param name="queue">The queue.</param>
/// <returns><c>true</c> if the user can access all the items in the queue, <c>false</c> otherwise.</returns>
private bool HasAccessToQueue(User user, IReadOnlyList<Guid> queue)
{
// Check if queue is empty.
if (queue is null || queue.Count == 0)
{
return true;
}
foreach (var itemId in queue)
{
var item = _libraryManager.GetItemById(itemId);
if (!item.IsVisibleStandalone(user))
{
return false;
}
}
return true;
}
private bool AllUsersHaveAccessToQueue(IReadOnlyList<Guid> queue)
{
// Check if queue is empty.
if (queue is null || queue.Count == 0)
{
return true;
}
// Get list of users.
var users = _participants
.Values
.Select(participant => _userManager.GetUserById(participant.UserId));
// Find problematic users.
var usersWithNoAccess = users.Where(user => !HasAccessToQueue(user, queue));
// All users must be able to access the queue.
return !usersWithNoAccess.Any();
}
/// <summary>
/// Checks if the group is empty.
/// </summary>
/// <returns><c>true</c> if the group is empty, <c>false</c> otherwise.</returns>
public bool IsGroupEmpty() => _participants.Count == 0;
/// <summary>
/// Initializes the group with the session's info.
/// </summary>
/// <param name="session">The session.</param>
/// <param name="request">The request.</param>
/// <param name="cancellationToken">The cancellation token.</param>
public void CreateGroup(SessionInfo session, NewGroupRequest request, CancellationToken cancellationToken)
{
GroupName = request.GroupName;
AddSession(session);
var sessionIsPlayingAnItem = session.FullNowPlayingItem is not null;
RestartCurrentItem();
if (sessionIsPlayingAnItem)
{
var playlist = session.NowPlayingQueue.Select(item => item.Id).ToList();
PlayQueue.Reset();
PlayQueue.SetPlaylist(playlist);
PlayQueue.SetPlayingItemById(session.FullNowPlayingItem.Id);
RunTimeTicks = session.FullNowPlayingItem.RunTimeTicks ?? 0;
PositionTicks = session.PlayState.PositionTicks ?? 0;
// Maintain playstate.
var waitingState = new WaitingGroupState(_loggerFactory)
{
ResumePlaying = !session.PlayState.IsPaused
};
SetState(waitingState);
}
var updateSession = NewSyncPlayGroupUpdate(GroupUpdateType.GroupJoined, GetInfo());
SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, updateSession, cancellationToken);
_state.SessionJoined(this, _state.Type, session, cancellationToken);
_logger.LogInformation("Session {SessionId} created group {GroupId}.", session.Id, GroupId.ToString());
}
/// <summary>
/// Adds the session to the group.
/// </summary>
/// <param name="session">The session.</param>
/// <param name="request">The request.</param>
/// <param name="cancellationToken">The cancellation token.</param>
public void SessionJoin(SessionInfo session, JoinGroupRequest request, CancellationToken cancellationToken)
{
AddSession(session);
var updateSession = NewSyncPlayGroupUpdate(GroupUpdateType.GroupJoined, GetInfo());
SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, updateSession, cancellationToken);
var updateOthers = NewSyncPlayGroupUpdate(GroupUpdateType.UserJoined, session.UserName);
SendGroupUpdate(session, SyncPlayBroadcastType.AllExceptCurrentSession, updateOthers, cancellationToken);
_state.SessionJoined(this, _state.Type, session, cancellationToken);
_logger.LogInformation("Session {SessionId} joined group {GroupId}.", session.Id, GroupId.ToString());
}
/// <summary>
/// Removes the session from the group.
/// </summary>
/// <param name="session">The session.</param>
/// <param name="request">The request.</param>
/// <param name="cancellationToken">The cancellation token.</param>
public void SessionLeave(SessionInfo session, LeaveGroupRequest request, CancellationToken cancellationToken)
{
_state.SessionLeaving(this, _state.Type, session, cancellationToken);
RemoveSession(session);
var updateSession = NewSyncPlayGroupUpdate(GroupUpdateType.GroupLeft, GroupId.ToString());
SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, updateSession, cancellationToken);
var updateOthers = NewSyncPlayGroupUpdate(GroupUpdateType.UserLeft, session.UserName);
SendGroupUpdate(session, SyncPlayBroadcastType.AllExceptCurrentSession, updateOthers, cancellationToken);
_logger.LogInformation("Session {SessionId} left group {GroupId}.", session.Id, GroupId.ToString());
}
/// <summary>
/// Handles the requested action by the session.
/// </summary>
/// <param name="session">The session.</param>
/// <param name="request">The requested action.</param>
/// <param name="cancellationToken">The cancellation token.</param>
public void HandleRequest(SessionInfo session, IGroupPlaybackRequest request, CancellationToken cancellationToken)
{
// The server's job is to maintain a consistent state for clients to reference
// and notify clients of state changes. The actual syncing of media playback
// happens client side. Clients are aware of the server's time and use it to sync.
_logger.LogInformation("Session {SessionId} requested {RequestType} in group {GroupId} that is {StateType}.", session.Id, request.Action, GroupId.ToString(), _state.Type);
// Apply requested changes to this group given its current state.
// Every request has a slightly different outcome depending on the group's state.
// There are currently four different group states that accomplish different goals:
// - Idle: in this state no media is playing and clients should be idle (playback is stopped).
// - Waiting: in this state the group is waiting for all the clients to be ready to start the playback,
// that is, they've either finished loading the media for the first time or they've finished buffering.
// Once all clients report to be ready the group's state can change to Playing or Paused.
// - Playing: clients have some media loaded and playback is unpaused.
// - Paused: clients have some media loaded but playback is currently paused.
request.Apply(this, _state, session, cancellationToken);
}
/// <summary>
/// Gets the info about the group for the clients.
/// </summary>
/// <returns>The group info for the clients.</returns>
public GroupInfoDto GetInfo()
{
var participants = _participants.Values.Select(session => session.UserName).Distinct().ToList();
return new GroupInfoDto(GroupId, GroupName, _state.Type, participants, DateTime.UtcNow);
}
/// <summary>
/// Checks if a user has access to all content in the play queue.
/// </summary>
/// <param name="user">The user.</param>
/// <returns><c>true</c> if the user can access the play queue; <c>false</c> otherwise.</returns>
public bool HasAccessToPlayQueue(User user)
{
var items = PlayQueue.GetPlaylist().Select(item => item.ItemId).ToList();
return HasAccessToQueue(user, items);
}
/// <inheritdoc />
public void SetIgnoreGroupWait(SessionInfo session, bool ignoreGroupWait)
{
if (_participants.TryGetValue(session.Id, out GroupMember value))
{
value.IgnoreGroupWait = ignoreGroupWait;
}
}
/// <inheritdoc />
public void SetState(IGroupState state)
{
_logger.LogInformation("Group {GroupId} switching from {FromStateType} to {ToStateType}.", GroupId.ToString(), _state.Type, state.Type);
this._state = state;
}
/// <inheritdoc />
public Task SendGroupUpdate<T>(SessionInfo from, SyncPlayBroadcastType type, GroupUpdate<T> message, CancellationToken cancellationToken)
{
IEnumerable<Task> GetTasks()
{
foreach (var sessionId in FilterSessions(from.Id, type))
{
yield return _sessionManager.SendSyncPlayGroupUpdate(sessionId, message, cancellationToken);
}
}
return Task.WhenAll(GetTasks());
}
/// <inheritdoc />
public Task SendCommand(SessionInfo from, SyncPlayBroadcastType type, SendCommand message, CancellationToken cancellationToken)
{
IEnumerable<Task> GetTasks()
{
foreach (var sessionId in FilterSessions(from.Id, type))
{
yield return _sessionManager.SendSyncPlayCommand(sessionId, message, cancellationToken);
}
}
return Task.WhenAll(GetTasks());
}
/// <inheritdoc />
public SendCommand NewSyncPlayCommand(SendCommandType type)
{
return new SendCommand(
GroupId,
PlayQueue.GetPlayingItemPlaylistId(),
LastActivity,
type,
PositionTicks,
DateTime.UtcNow);
}
/// <inheritdoc />
public GroupUpdate<T> NewSyncPlayGroupUpdate<T>(GroupUpdateType type, T data)
{
return new GroupUpdate<T>(GroupId, type, data);
}
/// <inheritdoc />
public long SanitizePositionTicks(long? positionTicks)
{
var ticks = positionTicks ?? 0;
return Math.Clamp(ticks, 0, RunTimeTicks);
}
/// <inheritdoc />
public void UpdatePing(SessionInfo session, long ping)
{
if (_participants.TryGetValue(session.Id, out GroupMember value))
{
value.Ping = ping;
}
}
/// <inheritdoc />
public long GetHighestPing()
{
long max = long.MinValue;
foreach (var session in _participants.Values)
{
max = Math.Max(max, session.Ping);
}
return max;
}
/// <inheritdoc />
public void SetBuffering(SessionInfo session, bool isBuffering)
{
if (_participants.TryGetValue(session.Id, out GroupMember value))
{
value.IsBuffering = isBuffering;
}
}
/// <inheritdoc />
public void SetAllBuffering(bool isBuffering)
{
foreach (var session in _participants.Values)
{
session.IsBuffering = isBuffering;
}
}
/// <inheritdoc />
public bool IsBuffering()
{
foreach (var session in _participants.Values)
{
if (session.IsBuffering && !session.IgnoreGroupWait)
{
return true;
}
}
return false;
}
/// <inheritdoc />
public bool SetPlayQueue(IReadOnlyList<Guid> playQueue, int playingItemPosition, long startPositionTicks)
{
// Ignore on empty queue or invalid item position.
if (playQueue.Count == 0 || playingItemPosition >= playQueue.Count || playingItemPosition < 0)
{
return false;
}
// Check if participants can access the new playing queue.
if (!AllUsersHaveAccessToQueue(playQueue))
{
return false;
}
PlayQueue.Reset();
PlayQueue.SetPlaylist(playQueue);
PlayQueue.SetPlayingItemByIndex(playingItemPosition);
var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
RunTimeTicks = item.RunTimeTicks ?? 0;
PositionTicks = startPositionTicks;
LastActivity = DateTime.UtcNow;
return true;
}
/// <inheritdoc />
public bool SetPlayingItem(Guid playlistItemId)
{
var itemFound = PlayQueue.SetPlayingItemByPlaylistId(playlistItemId);
if (itemFound)
{
var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
RunTimeTicks = item.RunTimeTicks ?? 0;
}
else
{
RunTimeTicks = 0;
}
RestartCurrentItem();
return itemFound;
}
/// <inheritdoc />
public void ClearPlayQueue(bool clearPlayingItem)
{
PlayQueue.ClearPlaylist(clearPlayingItem);
if (clearPlayingItem)
{
RestartCurrentItem();
}
}
/// <inheritdoc />
public bool RemoveFromPlayQueue(IReadOnlyList<Guid> playlistItemIds)
{
var playingItemRemoved = PlayQueue.RemoveFromPlaylist(playlistItemIds);
if (playingItemRemoved)
{
var itemId = PlayQueue.GetPlayingItemId();
if (!itemId.Equals(default))
{
var item = _libraryManager.GetItemById(itemId);
RunTimeTicks = item.RunTimeTicks ?? 0;
}
else
{
RunTimeTicks = 0;
}
RestartCurrentItem();
}
return playingItemRemoved;
}
/// <inheritdoc />
public bool MoveItemInPlayQueue(Guid playlistItemId, int newIndex)
{
return PlayQueue.MovePlaylistItem(playlistItemId, newIndex);
}
/// <inheritdoc />
public bool AddToPlayQueue(IReadOnlyList<Guid> newItems, GroupQueueMode mode)
{
// Ignore on empty list.
if (newItems.Count == 0)
{
return false;
}
// Check if participants can access the new playing queue.
if (!AllUsersHaveAccessToQueue(newItems))
{
return false;
}
if (mode.Equals(GroupQueueMode.QueueNext))
{
PlayQueue.QueueNext(newItems);
}
else
{
PlayQueue.Queue(newItems);
}
return true;
}
/// <inheritdoc />
public void RestartCurrentItem()
{
PositionTicks = 0;
LastActivity = DateTime.UtcNow;
}
/// <inheritdoc />
public bool NextItemInQueue()
{
var update = PlayQueue.Next();
if (update)
{
var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
RunTimeTicks = item.RunTimeTicks ?? 0;
RestartCurrentItem();
return true;
}
else
{
return false;
}
}
/// <inheritdoc />
public bool PreviousItemInQueue()
{
var update = PlayQueue.Previous();
if (update)
{
var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
RunTimeTicks = item.RunTimeTicks ?? 0;
RestartCurrentItem();
return true;
}
else
{
return false;
}
}
/// <inheritdoc />
public void SetRepeatMode(GroupRepeatMode mode)
{
PlayQueue.SetRepeatMode(mode);
}
/// <inheritdoc />
public void SetShuffleMode(GroupShuffleMode mode)
{
PlayQueue.SetShuffleMode(mode);
}
/// <inheritdoc />
public PlayQueueUpdate GetPlayQueueUpdate(PlayQueueUpdateReason reason)
{
var startPositionTicks = PositionTicks;
var isPlaying = _state.Type.Equals(GroupStateType.Playing);
if (isPlaying)
{
var currentTime = DateTime.UtcNow;
var elapsedTime = currentTime - LastActivity;
// Elapsed time is negative if event happens
// during the delay added to account for latency.
// In this phase clients haven't started the playback yet.
// In other words, LastActivity is in the future,
// when playback unpause is supposed to happen.
// Adjust ticks only if playback actually started.
startPositionTicks += Math.Max(elapsedTime.Ticks, 0);
}
return new PlayQueueUpdate(
reason,
PlayQueue.LastChange,
PlayQueue.GetPlaylist(),
PlayQueue.PlayingItemIndex,
startPositionTicks,
isPlaying,
PlayQueue.ShuffleMode,
PlayQueue.RepeatMode);
}
}
}