/// <summary>
/// Checks whether the <paramref name="action"/> has any aspects and if not
/// tries to restore them from the media library.
/// </summary>
/// <param name="action">The action to check.</param>
/// <returns>True if the aspects were present or successfully restored.</returns>
protected async Task <bool> TryRestoreAspects(FanArtManagerAction action)
{
//Already has aspects, nothing to do
if (action.Aspects != null)
{
return(true);
}
//No aspects, this resource was restored from disk, try and restore the aspects from the media library.
//Throttle the number of concurrent queries To avoid a spike during startup.
await _loadItemThrottle.WaitAsync(_cts.Token);
try
{
IMediaLibrary mediaLibrary = ServiceRegistration.Get <IMediaLibrary>();
MediaItemQuery query = new MediaItemQuery(null,
mediaLibrary.GetManagedMediaItemAspectMetadata().Keys,
new MediaItemIdFilter(action.MediaItemId));
var items = mediaLibrary.Search(query, false, null, true);
if (items != null && items.Count > 0)
{
action.Aspects = items[0].Aspects;
return(true);
}
ServiceRegistration.Get <ILogger>().Warn("FanArtActionBlock: Unable to restore FanArtAction, media item with id {0} was not found in the media library", action.MediaItemId);
return(false);
}
finally
{
_loadItemThrottle.Release();
}
}
/// <summary>
/// Schedules a new <see cref="FanArtManagerAction"/> for processing.
/// </summary>
/// <param name="action">The action to process.</param>
/// <returns>True if the action was scheduled.</returns>
public bool Post(FanArtManagerAction action)
{
_pendingFanArtDownloads.TryAdd(action.ActionId, action);
//Persist the newly pending action
_persistBlock.Post(null);
//Post the action for processing
return(_innerBlock.Post(action));
}
/// <summary>
/// Schedules a new <see cref="FanArtManagerAction"/> for processing.
/// </summary>
/// <param name="action">The action to process.</param>
/// <returns>True if the action was scheduled.</returns>
public bool Post(FanArtManagerAction action)
{
if (AddPendingAction(action.ActionId, action.Type, action.MediaItemId))
{
// Post the action for processing
return(_inputBlock.Post(action));
}
//We return success because the action is already scheduled
return(true);
}
/// <summary>
/// Removes the <paramref name="action"/> from the list of pending actions
/// so it is not restored on next server startup.
/// </summary>
/// <param name="action"></param>
private void OutputBlockMethod(FanArtManagerAction action)
{
FanArtManagerAction removedAction;
if (_pendingFanArtDownloads.TryRemove(action.ActionId, out removedAction))
{
removedAction.Aspects?.Clear();
//Remove the completed action from the persisted list of pending actions
_persistBlock.Post(null);
}
}
/// <summary>
/// Processes the <paramref name="action"/>.
/// </summary>
/// <param name="action">The action to process.</param>
/// <returns>Task that completes when the action has been processed.</returns>
private async Task <FanArtManagerAction> InnerBlockMethod(FanArtManagerAction action)
{
if (action.Type == ActionType.Collect)
{
//This action might have been restored in which case we need to reload the aspects
if (await TryRestoreAspects(action))
{
await CollectFanArt(action.MediaItemId, action.Aspects);
}
}
else if (action.Type == ActionType.Delete)
{
await DeleteFanArt(action.MediaItemId);
}
return(action);
}
/// <summary>
/// Schedules a new <see cref="FanArtManagerAction"/> for processing.
/// </summary>
/// <param name="action">The action to process.</param>
/// <returns>True if the action was scheduled.</returns>
public bool Post(FanArtManagerAction action)
{
AddPendingAction(action.ActionId, action.Type, action.MediaItemId);
// Post the action for processing
return(_inputBlock.Post(action));
}