jellyfin/MediaBrowser.Controller/SyncPlay/GroupStates/WaitingGroupState.cs

681 lines
30 KiB
C#

#nullable disable
using System;
using System.Threading;
using MediaBrowser.Controller.Session;
using MediaBrowser.Controller.SyncPlay.PlaybackRequests;
using MediaBrowser.Model.SyncPlay;
using Microsoft.Extensions.Logging;
namespace MediaBrowser.Controller.SyncPlay.GroupStates
{
/// <summary>
/// Class WaitingGroupState.
/// </summary>
/// <remarks>
/// Class is not thread-safe, external locking is required when accessing methods.
/// </remarks>
public class WaitingGroupState : AbstractGroupState
{
/// <summary>
/// The logger.
/// </summary>
private readonly ILogger<WaitingGroupState> _logger;
/// <summary>
/// Initializes a new instance of the <see cref="WaitingGroupState"/> class.
/// </summary>
/// <param name="loggerFactory">Instance of the <see cref="ILoggerFactory"/> interface.</param>
public WaitingGroupState(ILoggerFactory loggerFactory)
: base(loggerFactory)
{
_logger = LoggerFactory.CreateLogger<WaitingGroupState>();
}
/// <inheritdoc />
public override GroupStateType Type { get; } = GroupStateType.Waiting;
/// <summary>
/// Gets or sets a value indicating whether playback should resume when group is ready.
/// </summary>
public bool ResumePlaying { get; set; } = false;
/// <summary>
/// Gets or sets a value indicating whether the initial state has been set.
/// </summary>
private bool InitialStateSet { get; set; } = false;
/// <summary>
/// Gets or sets the group state before the first ever event.
/// </summary>
private GroupStateType InitialState { get; set; }
/// <inheritdoc />
public override void SessionJoined(IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
if (prevState.Equals(GroupStateType.Playing))
{
ResumePlaying = true;
// Pause group and compute the media playback position.
var currentTime = DateTime.UtcNow;
var elapsedTime = currentTime - context.LastActivity;
context.LastActivity = currentTime;
// 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.
// Seek only if playback actually started.
context.PositionTicks += Math.Max(elapsedTime.Ticks, 0);
}
// Prepare new session.
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.NewPlaylist);
var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, update, cancellationToken);
context.SetBuffering(session, true);
// Send pause command to all non-buffering sessions.
var command = context.NewSyncPlayCommand(SendCommandType.Pause);
context.SendCommand(session, SyncPlayBroadcastType.AllReady, command, cancellationToken);
}
/// <inheritdoc />
public override void SessionLeaving(IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
context.SetBuffering(session, false);
if (!context.IsBuffering())
{
if (ResumePlaying)
{
_logger.LogDebug("Session {SessionId} left group {GroupId}, notifying others to resume.", session.Id, context.GroupId.ToString());
// Client, that was buffering, left the group.
var playingState = new PlayingGroupState(LoggerFactory);
context.SetState(playingState);
var unpauseRequest = new UnpauseGroupRequest();
playingState.HandleRequest(unpauseRequest, context, Type, session, cancellationToken);
}
else
{
_logger.LogDebug("Session {SessionId} left group {GroupId}, returning to previous state.", session.Id, context.GroupId.ToString());
// Group is ready, returning to previous state.
var pausedState = new PausedGroupState(LoggerFactory);
context.SetState(pausedState);
}
}
}
/// <inheritdoc />
public override void HandleRequest(PlayGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
ResumePlaying = true;
var setQueueStatus = context.SetPlayQueue(request.PlayingQueue, request.PlayingItemPosition, request.StartPositionTicks);
if (!setQueueStatus)
{
_logger.LogError("Unable to set playing queue in group {GroupId}.", context.GroupId.ToString());
// Ignore request and return to previous state.
IGroupState newState = prevState switch {
GroupStateType.Playing => new PlayingGroupState(LoggerFactory),
GroupStateType.Paused => new PausedGroupState(LoggerFactory),
_ => new IdleGroupState(LoggerFactory)
};
context.SetState(newState);
return;
}
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.NewPlaylist);
var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
// Reset status of sessions and await for all Ready events.
context.SetAllBuffering(true);
_logger.LogDebug("Session {SessionId} set a new play queue in group {GroupId}.", session.Id, context.GroupId.ToString());
}
/// <inheritdoc />
public override void HandleRequest(SetPlaylistItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
ResumePlaying = true;
var result = context.SetPlayingItem(request.PlaylistItemId);
if (result)
{
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.SetCurrentItem);
var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
// Reset status of sessions and await for all Ready events.
context.SetAllBuffering(true);
}
else
{
// Return to old state.
IGroupState newState = prevState switch
{
GroupStateType.Playing => new PlayingGroupState(LoggerFactory),
GroupStateType.Paused => new PausedGroupState(LoggerFactory),
_ => new IdleGroupState(LoggerFactory)
};
context.SetState(newState);
_logger.LogDebug("Unable to change current playing item in group {GroupId}.", context.GroupId.ToString());
}
}
/// <inheritdoc />
public override void HandleRequest(UnpauseGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
if (prevState.Equals(GroupStateType.Idle))
{
ResumePlaying = true;
context.RestartCurrentItem();
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.NewPlaylist);
var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
// Reset status of sessions and await for all Ready events.
context.SetAllBuffering(true);
_logger.LogDebug("Group {GroupId} is waiting for all ready events.", context.GroupId.ToString());
}
else
{
if (ResumePlaying)
{
_logger.LogDebug("Forcing the playback to start in group {GroupId}. Group-wait is disabled until next state change.", context.GroupId.ToString());
// An Unpause request is forcing the playback to start, ignoring sessions that are not ready.
context.SetAllBuffering(false);
// Change state.
var playingState = new PlayingGroupState(LoggerFactory)
{
IgnoreBuffering = true
};
context.SetState(playingState);
playingState.HandleRequest(request, context, Type, session, cancellationToken);
}
else
{
// Group would have gone to paused state, now will go to playing state when ready.
ResumePlaying = true;
// Notify relevant state change event.
SendGroupStateUpdate(context, request, session, cancellationToken);
}
}
}
/// <inheritdoc />
public override void HandleRequest(PauseGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
// Wait for sessions to be ready, then switch to paused state.
ResumePlaying = false;
// Notify relevant state change event.
SendGroupStateUpdate(context, request, session, cancellationToken);
}
/// <inheritdoc />
public override void HandleRequest(StopGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
// Change state.
var idleState = new IdleGroupState(LoggerFactory);
context.SetState(idleState);
idleState.HandleRequest(request, context, Type, session, cancellationToken);
}
/// <inheritdoc />
public override void HandleRequest(SeekGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
if (prevState.Equals(GroupStateType.Playing))
{
ResumePlaying = true;
}
else if (prevState.Equals(GroupStateType.Paused))
{
ResumePlaying = false;
}
// Sanitize PositionTicks.
var ticks = context.SanitizePositionTicks(request.PositionTicks);
// Seek.
context.PositionTicks = ticks;
context.LastActivity = DateTime.UtcNow;
var command = context.NewSyncPlayCommand(SendCommandType.Seek);
context.SendCommand(session, SyncPlayBroadcastType.AllGroup, command, cancellationToken);
// Reset status of sessions and await for all Ready events.
context.SetAllBuffering(true);
// Notify relevant state change event.
SendGroupStateUpdate(context, request, session, cancellationToken);
}
/// <inheritdoc />
public override void HandleRequest(BufferGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
// Make sure the client is playing the correct item.
if (!request.PlaylistItemId.Equals(context.PlayQueue.GetPlayingItemPlaylistId()))
{
_logger.LogDebug("Session {SessionId} reported wrong playlist item in group {GroupId}.", session.Id, context.GroupId.ToString());
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.SetCurrentItem);
var updateSession = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, updateSession, cancellationToken);
context.SetBuffering(session, true);
return;
}
if (prevState.Equals(GroupStateType.Playing))
{
// Resume playback when all ready.
ResumePlaying = true;
context.SetBuffering(session, true);
// Pause group and compute the media playback position.
var currentTime = DateTime.UtcNow;
var elapsedTime = currentTime - context.LastActivity;
context.LastActivity = currentTime;
// 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.
// Seek only if playback actually started.
context.PositionTicks += Math.Max(elapsedTime.Ticks, 0);
// Send pause command to all non-buffering sessions.
var command = context.NewSyncPlayCommand(SendCommandType.Pause);
context.SendCommand(session, SyncPlayBroadcastType.AllReady, command, cancellationToken);
}
else if (prevState.Equals(GroupStateType.Paused))
{
// Don't resume playback when all ready.
ResumePlaying = false;
context.SetBuffering(session, true);
// Send pause command to buffering session.
var command = context.NewSyncPlayCommand(SendCommandType.Pause);
context.SendCommand(session, SyncPlayBroadcastType.CurrentSession, command, cancellationToken);
}
else if (prevState.Equals(GroupStateType.Waiting))
{
// Another session is now buffering.
context.SetBuffering(session, true);
if (!ResumePlaying)
{
// Force update for this session that should be paused.
var command = context.NewSyncPlayCommand(SendCommandType.Pause);
context.SendCommand(session, SyncPlayBroadcastType.CurrentSession, command, cancellationToken);
}
}
// Notify relevant state change event.
SendGroupStateUpdate(context, request, session, cancellationToken);
}
/// <inheritdoc />
public override void HandleRequest(ReadyGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
// Make sure the client is playing the correct item.
if (!request.PlaylistItemId.Equals(context.PlayQueue.GetPlayingItemPlaylistId()))
{
_logger.LogDebug("Session {SessionId} reported wrong playlist item in group {GroupId}.", session.Id, context.GroupId.ToString());
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.SetCurrentItem);
var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, update, cancellationToken);
context.SetBuffering(session, true);
return;
}
// Compute elapsed time between the client reported time and now.
// Elapsed time is used to estimate the client position when playback is unpaused.
// Ideally, the request is received and handled without major delays.
// However, to avoid waiting indefinitely when a client is not reporting a correct time,
// the elapsed time is ignored after a certain threshold.
var currentTime = DateTime.UtcNow;
var elapsedTime = currentTime.Subtract(request.When);
var timeSyncThresholdTicks = TimeSpan.FromMilliseconds(context.TimeSyncOffset).Ticks;
if (Math.Abs(elapsedTime.Ticks) > timeSyncThresholdTicks)
{
_logger.LogWarning("Session {SessionId} is not time syncing properly. Ignoring elapsed time.", session.Id);
elapsedTime = TimeSpan.Zero;
}
// Ignore elapsed time if client is paused.
if (!request.IsPlaying)
{
elapsedTime = TimeSpan.Zero;
}
var requestTicks = context.SanitizePositionTicks(request.PositionTicks);
var clientPosition = TimeSpan.FromTicks(requestTicks) + elapsedTime;
var delayTicks = context.PositionTicks - clientPosition.Ticks;
var maxPlaybackOffsetTicks = TimeSpan.FromMilliseconds(context.MaxPlaybackOffset).Ticks;
_logger.LogDebug("Session {SessionId} is at {PositionTicks} (delay of {Delay} seconds) in group {GroupId}.", session.Id, clientPosition, TimeSpan.FromTicks(delayTicks).TotalSeconds, context.GroupId.ToString());
if (ResumePlaying)
{
// Handle case where session reported as ready but in reality
// it has no clue of the real position nor the playback state.
if (!request.IsPlaying && Math.Abs(delayTicks) > maxPlaybackOffsetTicks)
{
// Session not ready at all.
context.SetBuffering(session, true);
// Correcting session's position.
var command = context.NewSyncPlayCommand(SendCommandType.Seek);
context.SendCommand(session, SyncPlayBroadcastType.CurrentSession, command, cancellationToken);
// Notify relevant state change event.
SendGroupStateUpdate(context, request, session, cancellationToken);
_logger.LogWarning("Session {SessionId} got lost in time, correcting.", session.Id);
return;
}
// Session is ready.
context.SetBuffering(session, false);
if (context.IsBuffering())
{
// Others are still buffering, tell this client to pause when ready.
var command = context.NewSyncPlayCommand(SendCommandType.Pause);
command.When = currentTime.AddTicks(delayTicks);
context.SendCommand(session, SyncPlayBroadcastType.CurrentSession, command, cancellationToken);
_logger.LogInformation("Session {SessionId} will pause when ready in {Delay} seconds. Group {GroupId} is waiting for all ready events.", session.Id, TimeSpan.FromTicks(delayTicks).TotalSeconds, context.GroupId.ToString());
}
else
{
// If all ready, then start playback.
// Let other clients resume as soon as the buffering client catches up.
if (delayTicks > context.GetHighestPing() * 2 * TimeSpan.TicksPerMillisecond)
{
// Client that was buffering is recovering, notifying others to resume.
context.LastActivity = currentTime.AddTicks(delayTicks);
var command = context.NewSyncPlayCommand(SendCommandType.Unpause);
var filter = SyncPlayBroadcastType.AllExceptCurrentSession;
if (!request.IsPlaying)
{
filter = SyncPlayBroadcastType.AllGroup;
}
context.SendCommand(session, filter, command, cancellationToken);
_logger.LogInformation("Session {SessionId} is recovering, group {GroupId} will resume in {Delay} seconds.", session.Id, context.GroupId.ToString(), TimeSpan.FromTicks(delayTicks).TotalSeconds);
}
else
{
// Client, that was buffering, resumed playback but did not update others in time.
delayTicks = context.GetHighestPing() * 2 * TimeSpan.TicksPerMillisecond;
delayTicks = Math.Max(delayTicks, context.DefaultPing);
context.LastActivity = currentTime.AddTicks(delayTicks);
var command = context.NewSyncPlayCommand(SendCommandType.Unpause);
context.SendCommand(session, SyncPlayBroadcastType.AllGroup, command, cancellationToken);
_logger.LogWarning("Session {SessionId} resumed playback, group {GroupId} has {Delay} seconds to recover.", session.Id, context.GroupId.ToString(), TimeSpan.FromTicks(delayTicks).TotalSeconds);
}
// Change state.
var playingState = new PlayingGroupState(LoggerFactory);
context.SetState(playingState);
playingState.HandleRequest(request, context, Type, session, cancellationToken);
}
}
else
{
// Check that session is really ready, tolerate player imperfections under a certain threshold.
if (Math.Abs(context.PositionTicks - requestTicks) > maxPlaybackOffsetTicks)
{
// Session still not ready.
context.SetBuffering(session, true);
// Session is seeking to wrong position, correcting.
var command = context.NewSyncPlayCommand(SendCommandType.Seek);
context.SendCommand(session, SyncPlayBroadcastType.CurrentSession, command, cancellationToken);
// Notify relevant state change event.
SendGroupStateUpdate(context, request, session, cancellationToken);
_logger.LogWarning("Session {SessionId} is seeking to wrong position, correcting.", session.Id);
return;
}
// Session is ready.
context.SetBuffering(session, false);
if (!context.IsBuffering())
{
_logger.LogDebug("Session {SessionId} is ready, group {GroupId} is ready.", session.Id, context.GroupId.ToString());
// Group is ready, returning to previous state.
var pausedState = new PausedGroupState(LoggerFactory);
context.SetState(pausedState);
if (InitialState.Equals(GroupStateType.Playing))
{
// Group went from playing to waiting state and a pause request occurred while waiting.
var pauseRequest = new PauseGroupRequest();
pausedState.HandleRequest(pauseRequest, context, Type, session, cancellationToken);
}
else if (InitialState.Equals(GroupStateType.Paused))
{
pausedState.HandleRequest(request, context, Type, session, cancellationToken);
}
}
}
}
/// <inheritdoc />
public override void HandleRequest(NextItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
ResumePlaying = true;
// Make sure the client knows the playing item, to avoid duplicate requests.
if (!request.PlaylistItemId.Equals(context.PlayQueue.GetPlayingItemPlaylistId()))
{
_logger.LogDebug("Session {SessionId} provided the wrong playlist item for group {GroupId}.", session.Id, context.GroupId.ToString());
return;
}
var newItem = context.NextItemInQueue();
if (newItem)
{
// Send playing-queue update.
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.NextItem);
var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
// Reset status of sessions and await for all Ready events.
context.SetAllBuffering(true);
}
else
{
// Return to old state.
IGroupState newState = prevState switch
{
GroupStateType.Playing => new PlayingGroupState(LoggerFactory),
GroupStateType.Paused => new PausedGroupState(LoggerFactory),
_ => new IdleGroupState(LoggerFactory)
};
context.SetState(newState);
_logger.LogDebug("No next item available in group {GroupId}.", context.GroupId.ToString());
}
}
/// <inheritdoc />
public override void HandleRequest(PreviousItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
// Save state if first event.
if (!InitialStateSet)
{
InitialState = prevState;
InitialStateSet = true;
}
ResumePlaying = true;
// Make sure the client knows the playing item, to avoid duplicate requests.
if (!request.PlaylistItemId.Equals(context.PlayQueue.GetPlayingItemPlaylistId()))
{
_logger.LogDebug("Session {SessionId} provided the wrong playlist item for group {GroupId}.", session.Id, context.GroupId.ToString());
return;
}
var newItem = context.PreviousItemInQueue();
if (newItem)
{
// Send playing-queue update.
var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.PreviousItem);
var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
// Reset status of sessions and await for all Ready events.
context.SetAllBuffering(true);
}
else
{
// Return to old state.
IGroupState newState = prevState switch
{
GroupStateType.Playing => new PlayingGroupState(LoggerFactory),
GroupStateType.Paused => new PausedGroupState(LoggerFactory),
_ => new IdleGroupState(LoggerFactory)
};
context.SetState(newState);
_logger.LogDebug("No previous item available in group {GroupId}.", context.GroupId.ToString());
}
}
/// <inheritdoc />
public override void HandleRequest(IgnoreWaitGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
{
context.SetIgnoreGroupWait(session, request.IgnoreWait);
if (!context.IsBuffering())
{
_logger.LogDebug("Ignoring session {SessionId}, group {GroupId} is ready.", session.Id, context.GroupId.ToString());
if (ResumePlaying)
{
// Client, that was buffering, stopped following playback.
var playingState = new PlayingGroupState(LoggerFactory);
context.SetState(playingState);
var unpauseRequest = new UnpauseGroupRequest();
playingState.HandleRequest(unpauseRequest, context, Type, session, cancellationToken);
}
else
{
// Group is ready, returning to previous state.
var pausedState = new PausedGroupState(LoggerFactory);
context.SetState(pausedState);
}
}
}
}
}