Grammar Composition System

/src/branch/20110407-thread-priority/agree-parse/chart-notify.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;

using glue.Collections.XSpinLock;
using glue.Tasks;
using glue.Extensions.Enumerable;

namespace agree.Parse
{
	abstract public partial class SubscriptionChart<T> : TaskCancellationChart<T> where T : ChartBase<T>.IMotherDaughter, IEquatable<T>
	{
		///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
		///
		/// N O T I F I C A T I O N   S O U R C E 
		///
		///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
		[DebuggerDisplay("Right of {i_col}: {this.Count} subscribers")]
		abstract internal class NotificationSource : AtomicSequenceList<ActiveEdge>
		{
			readonly protected SubscriptionChart<T> m_chart;
			readonly protected int i_col;

			protected abstract IEnumerable<IParseChartEdge> GetRetroactiveEdges(uint i_seq);

			///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
			/// <summary>
			/// 
			/// </summary>
			///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
			public NotificationSource(SubscriptionChart<T> chart, int i_col)
				: base(chart.AtomicStamp)
			{
				this.m_chart = chart;
				this.i_col = i_col;
			}

			///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
			/// <summary>
			/// This is the normal (non-retroactive) subscription delivery mechanism.
			/// </summary>
			///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
			internal void SendToAllAsync(IParseChartEdge pce)
			{
				foreach (ActiveEdge ace in this.EnumerateSeq(pce.SequenceId))
					ace.TryMatchEdge(pce);
			}

			///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
			/// <summary>
			/// Add the target to the list of subscribers. Because rule_targets is a list that is interlocked with the
			/// ChartEdge stamping sequence, Add() atomically imposes an (arbitrary) partition upon all past (and future)
			/// ChartEdges such that those which arrive prior to the sequencing point are sent by the retroactive mechanism,
			/// and ChartEdges sent afterwards will be posted to the target via the subscription delivery mechanism.
			/// </summary>
			///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
			public void Subscribe(ActiveEdge ace)
			{
				if (!ace.IsInert(m_chart.AtomicStamp))
					throw new InvalidOperationException("Target is already active; cannot support atomic activation.");

				// add and set a sequence barrier
				this.Add(ace);

				// Using the sequence stamp, only send retroactive ChartEdges to the newly connected target.
				foreach (IParseChartEdge pce in GetRetroactiveEdges(ace.SequenceId))
					ace.TryMatchEdge(pce);
			}
		};

		///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
		///
		/// 
		///
		///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
		internal class LeftNotificationSource : NotificationSource
		{
			public LeftNotificationSource(SubscriptionChart<T> chart, int i_left_of) : base(chart, i_left_of) { }

			protected override IEnumerable<IParseChartEdge> GetRetroactiveEdges(uint i_seq)
			{
				return m_chart.GetLeftAlignedEdges(i_col - 1, i_seq);
			}
		};

		///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
		///
		/// 
		///
		///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
		internal class RightNotificationSource : NotificationSource
		{
			public RightNotificationSource(SubscriptionChart<T> chart, int i_right_of) : base(chart, i_right_of) { }

			protected override IEnumerable<IParseChartEdge> GetRetroactiveEdges(uint i_seq)
			{
				return m_chart.GetRightAlignedEdges(i_col + 1, i_seq);
			}
		};
	};
}