public void DestroyChannelBucket(ChannelBucket type, ulong channelId)
{
//Assume this object is locked
RequestQueueBucket bucket;
_channelBuckets[(int)type].TryRemove(channelId, out bucket);
}
/// <summary>
/// Picks a random asset from the content exchanger-generated Playlist
/// </summary>
/// <param name="playlist">The content exchanger-generated Playlist</param>
/// <param name="assetScheduler">Asset Scheduler object that determines which assets are temporally capable of being played</param>
/// <returns>The information on the content playlist asset, null if no available asset found</returns>
private ChannelAssetAssociation PickRandomContentPlaylistAsset()
{
// this counts the number of buckets we have already tried and have not found any content in.
int noConsumedChannelBuckets = _consumedChannelBuckets.Count;
_logger.WriteMessage("Attempted Channel Buckets: " + noConsumedChannelBuckets);
// if user has not subscribed to any channels or if all channel buckets have been searched, return null
// clear consumed buckets to search again on the next run
if (_noChannelBuckets == 0 || _noChannelBuckets == noConsumedChannelBuckets)
{
_consumedChannelBuckets.Clear();
_consumedContentPlaylistAssets.Clear();
if (_noChannelBuckets > 0)
{
_logger.WriteMessage("All channel buckets searched. No content asset can be played at this time.");
}
else
{
_logger.WriteMessage("No channel buckets in playlist. No content asset can be played at this time.");
}
return(null);
}
ChannelBucket cb = GetRandomChannelBucket(_playlist);
_logger.WriteMessage("channel bucket selected successfully");
ChannelAssetAssociation caa = GetRandomContentPlaylistAsset(cb);
if (caa == null)
{
_consumedChannelBuckets.Add(cb);
_logger.WriteMessage("no content in this channel was selected. Channel bucket will not be attempted again in this run. Attempting another channel bucket.");
caa = PickRandomContentPlaylistAsset();
}
else
{
_logger.WriteMessage("content asset selected: " + caa.PlaylistAsset.AssetID + " in channel: " + caa.ChannelID);
}
// at this point the algorithm has succeeded or has processed all buckets and assets and found no content available
// clear consumed
_consumedChannelBuckets.Clear();
_consumedContentPlaylistAssets.Clear();
// next pick will include content web assets if due to network/website unavailability those were excluded
_bIncludeContentWebAssets = true;
return(caa); // if this is null, there is no content asset available for playing
}
public static void NormalizeChannelBucketPlayingProbabilities(HashSet <ChannelBucket> channelBuckets, Logger logger)
{
float sumPlayingProbabilities = 0F;
float normalisedPlayingProbability = -1F;
float previousLowerThresholdNormalised = 0F;
foreach (ChannelBucket cb in channelBuckets)
{
sumPlayingProbabilities += cb.PlayingProbabilityUnnormalized;
}
// normalize playing probabilities if there is at least a playing probability greater than 0.
if (sumPlayingProbabilities <= 0)
{
return;
}
int noChannelBuckets = channelBuckets.Count;
for (int i = 0; i < noChannelBuckets; i++)
{
ChannelBucket cb = channelBuckets.ElementAt(i);
normalisedPlayingProbability = cb.PlayingProbabilityUnnormalized / sumPlayingProbabilities;
cb.PlayingProbabilityNormalised = normalisedPlayingProbability;
// calculate lower and upper threshold for random play
cb.LowerThresholdNormalised = previousLowerThresholdNormalised;
// make last content asset's higher normalized threshold equal to 1, else add the newly calculated normalized weighting.
if (i < noChannelBuckets - 1)
{
cb.HigherThresholdNormalised = previousLowerThresholdNormalised + normalisedPlayingProbability;
}
else
{
cb.HigherThresholdNormalised = 1;
}
// increment lower threshold for next loop run
previousLowerThresholdNormalised += normalisedPlayingProbability;
}
}
// filter non consumed content assets
private IEnumerable <ContentPlaylistAsset> GetPlayableContentPlaylistAssetsExcludingConsumed(ChannelBucket cb)
{
_logger.WriteMessage("shortlisting non attempted content assets that can be displayed and selecting one randomly.");
// filter by whether content assets are consumed
var channelBucketContentNonConsumedPlayable = from ContentPlaylistAsset contentPlaylistAsset in cb.ContentAssets
where !_consumedContentPlaylistAssets.Contains(contentPlaylistAsset)
select contentPlaylistAsset;
_logger.WriteMessage("successfully selected the non attempted content.");
// further filter by date bounds
var channelBucketContentDateNonConsumedPlayable = from ContentPlaylistAsset contentPlaylistAsset in channelBucketContentNonConsumedPlayable
where contentPlaylistAsset.StartDateTime <= DateTime.Now &&
contentPlaylistAsset.EndDateTime >= DateTime.Now
select contentPlaylistAsset;
_logger.WriteMessage("successfully selected the non attempted content whose start and end date/time surround today/now.");
// further filter assets that passed date bound filtering by content assets with no scheduling information
var channelBucketContentDateNonConsumedNoScheduleInfoPlayable = from ContentPlaylistAsset contentPlaylistAsset in channelBucketContentDateNonConsumedPlayable
where contentPlaylistAsset.ScheduleInfo.Length == 0
select contentPlaylistAsset;
_logger.WriteMessage("successfully selected the non attempted content with no scheduling info.");
// further filter assets that passed date bound filtering by content assets with scheduling information that permits them to be played at this time
var channelBucketContentDateNonConsumedWithScheduleInfoPlayable = from ContentPlaylistAsset contentPlaylistAsset in channelBucketContentDateNonConsumedPlayable
where _assetScheduler.IsAssetPlayable(contentPlaylistAsset.ScheduleInfo)
select contentPlaylistAsset;
_logger.WriteMessage("successfully selected the non attempted content with permitted scheduling info.");
// union of assets passed scheduling information and assets with no scheduling information
var playableContentAssets = channelBucketContentDateNonConsumedNoScheduleInfoPlayable.Union(channelBucketContentDateNonConsumedWithScheduleInfoPlayable);
_logger.WriteMessage("successfully combined playable content with permitted scheduling info and without scheduling info.");
// of those assets found, which ones are available and can be played due to memory restrictions if any
var playableContentAssetsExisting = from ContentPlaylistAsset contentPlaylistAsset in playableContentAssets
where ((contentPlaylistAsset.PlayerType == PlayerType.WebSite && AssetWebsiteExists(contentPlaylistAsset.AssetWebSite)) ||
contentPlaylistAsset.PlayerType != PlayerType.WebSite && AssetFileExists(contentPlaylistAsset.GetAssetFilenameGUIDSuffix(), contentPlaylistAsset.AssetFilename) &&
(!_bInsufficientMemoryForLargeFiles || IsNonLargeFile(contentPlaylistAsset)))
select contentPlaylistAsset;
_logger.WriteMessage("successfully selected content that is available locally or online.");
return(playableContentAssetsExisting);
}
// picks a random content asset from channel bucket
private ChannelAssetAssociation GetRandomContentPlaylistAsset(ChannelBucket cb)
{
// Randomly pick asset from full bucket list
// check whether selected asset can be played according to temporal scheduling
// if not pick again. This will be repeated 20 times.
for (int i = 0; i < 20; i++)
{
ContentPlaylistAsset contentPlaylistAsset = GetRandomElement(cb.ContentAssets);
if (contentPlaylistAsset == null)
{
_logger.WriteMessage("no asset found in this channel bucket.");
return(null);
}
_logger.WriteMessage("content asset: " + contentPlaylistAsset.AssetID +
" selected randomly. Determining if it can be played at this time.");
if (_consumedContentPlaylistAssets.Contains(contentPlaylistAsset))
{
continue;
}
_logger.WriteMessage("content asset has not been attempted on this run.");
if (!((contentPlaylistAsset.StartDateTime <= DateTime.Now &&
contentPlaylistAsset.EndDateTime >= DateTime.Now
&&
(contentPlaylistAsset.PlayerType != PlayerType.WebSite ||
_bIncludeContentWebAssets && contentPlaylistAsset.PlayerType == PlayerType.WebSite))) ||
(!_assetScheduler.IsAssetPlayable(contentPlaylistAsset.ScheduleInfo)))
{
_consumedContentPlaylistAssets.Add(contentPlaylistAsset);
continue;
}
_logger.WriteMessage("content asset has no schedule info. Checking if it is available.");
if (contentPlaylistAsset.PlayerType == PlayerType.WebSite)
{
_logger.WriteMessage("content asset is a website. Checking if it is available online.");
if (AssetWebsiteExists(contentPlaylistAsset.AssetWebSite))
{
_logger.WriteMessage("content asset " + contentPlaylistAsset.AssetWebSite +
" is available online and will be selected.");
return(new ChannelAssetAssociation(cb.ChannelID, contentPlaylistAsset));
}
_logger.WriteMessage("content asset " + contentPlaylistAsset.AssetWebSite +
" is not available online. Disabling selection of web content for this run.");
_bIncludeContentWebAssets = false;
}
else
{
_logger.WriteMessage("content asset is a non-website. Checking if it is available on disk.");
if (AssetFileExists(contentPlaylistAsset.GetAssetFilenameGUIDSuffix(),
contentPlaylistAsset.AssetFilename))
{
_logger.WriteMessage("content asset " + contentPlaylistAsset.AssetFilename +
" exists on disk.");
if (!_bInsufficientMemoryForLargeFiles || IsNonLargeFile(contentPlaylistAsset))
{
_logger.WriteTimestampedMessage("Content asset " + contentPlaylistAsset.AssetFilename +
" can be played.");
return(new ChannelAssetAssociation(cb.ChannelID, contentPlaylistAsset));
}
_logger.WriteTimestampedMessage(
"There are physical memory restrictions and content asset " +
contentPlaylistAsset.AssetFilename + " cannot be played");
}
else
{
_logger.WriteMessage("content asset " + contentPlaylistAsset.AssetFilename +
" does not exist on disk.");
}
}
_consumedContentPlaylistAssets.Add(contentPlaylistAsset);
}
// if nothing found go through Channel Bucket's entire list (excluding the consumed ones),
// checking what CAN be displayed and create a shortlist
// then randomly pick one from the shortlist.
ContentPlaylistAsset cpa = GetRandomElement(GetPlayableContentPlaylistAssetsExcludingConsumed(cb));
if (cpa == null)
{
return(null);
}
return(new ChannelAssetAssociation(cb.ChannelID, cpa));
}
public static Bucket GetBucketInfo(ChannelBucket bucket) => _channelLimits[bucket];
private RequestQueueBucket GetChannelBucket(ChannelBucket type, ulong channelId)
{
return(_channelBuckets[(int)type].GetOrAdd(channelId, _ => CreateBucket(_channelLimits[type])));
}