/// <summary>
/// Creates a view of the messages identified by the matching parameters and asynchronously fills it in.
/// View mode can be one of three values:
/// Fixed - fixed range based on start and end times
/// TailCount - sliding dynamic range that includes the tail of the underlying data based on quantity
/// TailRange - sliding dynamic range that includes the tail of the underlying data based on function.
/// </summary>
/// <typeparam name="T">The type of the message to read.</typeparam>
/// <param name="streamSource">The stream source indicating which stream to read from.</param>
/// <param name="viewMode">Mode the view will be created in.</param>
/// <param name="startTime">Start time of messages to read.</param>
/// <param name="endTime">End time of messages to read.</param>
/// <param name="tailCount">Number of messages to included in tail.</param>
/// <param name="tailRange">Function to determine range included in tail.</param>
/// <returns>Observable view of data.</returns>
internal ObservableKeyedCache <DateTime, Message <T> > .ObservableKeyedView ReadStream <T>(
StreamSource streamSource,
ObservableKeyedCache <DateTime, Message <T> > .ObservableKeyedView.ViewMode viewMode,
DateTime startTime,
DateTime endTime,
uint tailCount,
Func <DateTime, DateTime> tailRange)
{
return(this.GetOrCreateStreamCacheByStreamSource <T>(streamSource, streamSource.StreamAdapter).ReadStream <T>(viewMode, startTime, endTime, tailCount, tailRange));
}
/// <summary>
/// Initializes a new instance of the <see cref="StreamDataProvider{T}"/> class.
/// </summary>
/// <param name="streamSource">The stream source.</param>
public StreamDataProvider(StreamSource streamSource)
{
this.Allocator = streamSource.Allocator != null ? () => streamSource.Allocator() : null;
this.Deallocator = streamSource.Deallocator != null ? t => streamSource.Deallocator(t) : null;
this.StreamName = streamSource.StreamName;
this.ReadRequestsInternal = new List <ReadRequest>();
this.ReadRequests = new ReadOnlyCollection <ReadRequest>(this.ReadRequestsInternal);
}
/// <summary>
/// Initializes a new instance of the <see cref="StreamIntervalProvider{T}"/> class.
/// </summary>
/// <param name="streamSource">The stream source.</param>
public StreamIntervalProvider(StreamSource streamSource)
: base(streamSource)
{
this.StreamAdapter = streamSource.StreamAdapter;
var itemComparer = Comparer <Message <T> > .Create((m1, m2) => m1.OriginatingTime.CompareTo(m2.OriginatingTime));
this.data = new ObservableKeyedCache <DateTime, Message <T> >(null, itemComparer, m => m.OriginatingTime);
this.data.CollectionChanged += this.OnCollectionChanged;
this.dataBuffer = new List <Message <T> >(1000);
}
/// <summary>
/// Initializes a new instance of the <see cref="StreamSummaryManager"/> class.
/// </summary>
/// <param name="streamSource">A stream source that specifies the store and stream that will be summarized.</param>
public StreamSummaryManager(StreamSource streamSource)
{
if (streamSource == null)
{
throw new ArgumentNullException(nameof(streamSource));
}
this.streamSource = streamSource;
this.summaryCaches = new Dictionary <TimeSpan, IStreamSummary>();
this.consumers = new List <Guid>();
}
/// <summary>
/// Initializes a new instance of the <see cref="StreamValueProvider{T}"/> class.
/// </summary>
/// <param name="streamSource">The stream source.</param>
public StreamValueProvider(StreamSource streamSource)
: base(streamSource)
{
this.indexView = null;
this.publishers = new Dictionary <RelativeTimeInterval, List <IStreamValuePublisher <TSource> > >();
var indexComparer = Comparer <MessageIndex <TSource> > .Create((i1, i2) => i1.OriginatingTime.CompareTo(i2.OriginatingTime));
this.index = new ObservableKeyedCache <DateTime, MessageIndex <TSource> >(null, indexComparer, ie => ie.OriginatingTime);
this.indexBuffer = new List <MessageIndex <TSource> >(1000);
}
/// <summary>
/// Gets or creates a stream value provider for a specified stream source.
/// </summary>
/// <typeparam name="T">The type of messages in the stream.</typeparam>
/// <param name="streamSource">The stream source.</param>
/// <returns>The stream value provider.</returns>
internal IStreamValueProvider GetOrCreateStreamValueProvider <T>(StreamSource streamSource)
{
var streamValueProvider = this.GetStreamValueProviderOrDefault(streamSource.StreamName);
if (streamValueProvider == null)
{
streamValueProvider = new StreamValueProvider <T>(streamSource);
(streamValueProvider as StreamDataProvider <T>).StreamReadError += this.OnStreamReadError;
lock (this.streamDataProviders)
{
this.streamDataProviders.Add(streamValueProvider);
}
}
return(streamValueProvider);
}
/// <summary>
/// Gets or creates a stream interval provider for a specified stream source.
/// </summary>
/// <typeparam name="T">The type of messages in the stream.</typeparam>
/// <param name="streamSource">The stream source.</param>
/// <returns>The stream interval provider.</returns>
internal IStreamIntervalProvider GetOrCreateStreamIntervalProvider <T>(StreamSource streamSource)
{
var streamIntervalProvider = this.GetStreamIntervalProviderOrDefault(streamSource.StreamName, streamSource.StreamAdapter);
if (streamIntervalProvider == null)
{
streamIntervalProvider = new StreamIntervalProvider <T>(streamSource);
streamIntervalProvider.NoRemainingSubscribers += this.StreamDataProvider_NoRemainingSubscribers;
(streamIntervalProvider as StreamDataProvider <T>).StreamReadError += this.OnStreamReadError;
lock (this.streamDataProviders)
{
this.streamDataProviders.Add(streamIntervalProvider);
}
}
return(streamIntervalProvider);
}
private IStreamSummary GetOrCreateStreamSummary <T>(StreamSource streamSource, TimeSpan interval)
{
// Get the summary cache if it exists.
IStreamSummary summaryCache = this.GetStreamSummaryOrDefault(interval);
// A summary cache with the required interval does not exist, so create it now.
if (summaryCache == null)
{
summaryCache = typeof(StreamSummary <,>)
.MakeGenericType(streamSource.Summarizer.SourceType, streamSource.Summarizer.DestinationType)
.GetConstructor(new Type[] { typeof(StreamSource), typeof(TimeSpan), typeof(uint) })
.Invoke(new object[] { streamSource, interval, DefaultCacheCapacity }) as IStreamSummary;
this.summaryCaches[interval] = summaryCache ?? throw new InvalidOperationException("Unable to create instance of summary cache");
}
return(summaryCache);
}
/// <summary>
/// Initializes a new instance of the <see cref="StreamSummary{TSource, TDestination}"/> class.
/// </summary>
/// <param name="streamSource">Stream source indicating which stream to summarize.</param>
/// <param name="interval">The time interval over which summary <see cref="IntervalData"/> values are calculated.</param>
/// <param name="maxCacheSize">The maximum amount of data to cache before purging older summarized data.</param>
public StreamSummary(StreamSource streamSource, TimeSpan interval, uint maxCacheSize)
{
this.streamSource = streamSource;
this.interval = interval;
this.maxCacheSize = maxCacheSize;
this.summaryDataBuffer = new List <List <IntervalData <TDestination> > >();
this.keySelector = s => Summarizer <TSource, TDestination> .GetIntervalStartTime(s.OriginatingTime, interval);
this.itemComparer = Comparer <IntervalData <TDestination> > .Create((r1, r2) => this.keySelector(r1).CompareTo(this.keySelector(r2)));
this.summaryCache = new ObservableKeyedCache <DateTime, IntervalData <TDestination> >(null, this.itemComparer, this.keySelector);
this.activeStreamViews = new Dictionary <Tuple <DateTime, DateTime, uint, Func <DateTime, DateTime> >, ObservableKeyedCache <DateTime, Message <TSource> > .ObservableKeyedView>();
this.cachedSummaryViews = new Dictionary <Tuple <DateTime, DateTime, uint, Func <DateTime, DateTime> >, ObservableKeyedCache <DateTime, IntervalData <TDestination> > .ObservableKeyedView>();
// Cache the summarizer (cast to the correct type) to call its methods later on without dynamic binding
this.summarizer = this.streamSource.Summarizer as ISummarizer <TSource, TDestination>;
}
/// <summary>
/// Gets a view over the specified time range of the cached summary data.
/// </summary>
/// <typeparam name="T">The summary data type.</typeparam>
/// <param name="streamSource">The stream source indicating which stream to read from.</param>
/// <param name="viewMode">The view mode, which may be either fixed or live data.</param>
/// <param name="startTime">The start time of the view range.</param>
/// <param name="endTime">The end time of the view range.</param>
/// <param name="interval">The time interval each summary value should cover.</param>
/// <param name="tailCount">Not yet supported and should be set to zero.</param>
/// <param name="tailRange">Tail duration function. Computes the view range start time given an end time. Applies to live view mode only.</param>
/// <returns>A view over the cached summary data that covers the specified time range.</returns>
public ObservableKeyedCache <DateTime, IntervalData <T> > .ObservableKeyedView ReadSummary <T>(
StreamSource streamSource,
ObservableKeyedCache <DateTime, IntervalData <T> > .ObservableKeyedView.ViewMode viewMode,
DateTime startTime,
DateTime endTime,
TimeSpan interval,
uint tailCount,
Func <DateTime, DateTime> tailRange)
{
if (startTime > DateTime.MinValue)
{
// Extend the start time to include the preceding data point to facilitate continuous plots.
startTime = this.FindPreviousDataPoint <T>(startTime, interval);
}
if (endTime < DateTime.MaxValue)
{
// Extend the start time to include the next data point to facilitate continuous plots.
endTime = this.FindNextDataPoint <T>(endTime, interval);
}
return(this.GetOrCreateSummaryCache(streamSource, interval).ReadSummary <T>(viewMode, startTime, endTime, tailCount, tailRange));
}
/// <summary> /// Performs a series of updates to the messages in a stream. /// </summary> /// <typeparam name="T">The type of the messages in the stream.</typeparam> /// <param name="streamSource">The stream source indicating which stream to read from.</param> /// <param name="updates">A collection of updates to perform.</param> internal void UpdateStream <T>(StreamSource streamSource, IEnumerable <StreamUpdate <T> > updates) => this.GetStreamIntervalProviderOrDefault(streamSource.StreamName, streamSource.StreamAdapter) .UpdateStream <T>(updates);
/// <summary> /// Gets the time of the nearest message to a specified time, on a specified stream. /// </summary> /// <param name="streamSource">The stream source specifying the stream of interest.</param> /// <param name="time">The time to find the nearest message to.</param> /// <param name="nearestMessageType">The type of nearest message to find.</param> /// <returns>The time of the nearest message, if one is found or null otherwise.</returns> internal DateTime?GetTimeOfNearestMessage(StreamSource streamSource, DateTime time, NearestMessageType nearestMessageType) => this.GetStreamProviderOrDefault(streamSource.StreamName) .GetTimeOfNearestMessage(time, nearestMessageType);
/// <summary>
/// Performs a series of updates to the messages in a stream.
/// </summary>
/// <typeparam name="T">The type of the messages in the stream.</typeparam>
/// <param name="streamSource">The stream source indicating which stream to read from.</param>
/// <param name="updates">A collection of updates to perform.</param>
internal void UpdateStream <T>(StreamSource streamSource, IEnumerable <StreamUpdate <T> > updates)
{
this.GetExistingStreamCache(streamSource, streamSource.StreamAdapter).UpdateStream <T>(updates);
}
/// <summary>
/// Gets the supplemental metadata for a stream.
/// </summary>
/// <typeparam name="TSupplementalMetadata">The type of the supplemental metadata.</typeparam>
/// <param name="streamSource">The stream source indicating which stream to read from.</param>
/// <returns>The supplemental metadata for the stream.</returns>
internal TSupplementalMetadata GetSupplementalMetadata <TSupplementalMetadata>(StreamSource streamSource)
{
return(this.streamReader.GetSupplementalMetadata <TSupplementalMetadata>(streamSource.StreamName));
}
