延迟添加队列

using System;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace AnfleCrawler.Common
{
    /// <summary>
    /// 延迟添加队列
    /// </summary>
    internal class LagPattern : Disposable
    {
        private static readonly List<LagPattern> Set = new List<LagPattern>();
        private const double PerCount = 50d;
        private WeakReference _weakRef;
        private int _depth;
        private object _state;
        private JobTimer _job;

        private PageCrawler Weak
        {
            get
            {
                if (!_weakRef.IsAlive)
                {
                    throw new InvalidOperationException("Wrap Dead");
                }
                return (PageCrawler)_weakRef.Target;
            }
        }

        public LagPattern(PageCrawler wrap, StringPatternGenerator urlGen, int depth, object state)
        {
            Contract.Requires(wrap != null && urlGen != null);

            _weakRef = new WeakReference(wrap);
            _depth = depth;
            _state = state;

            var tor = urlGen.GetEnumerator();
            int totalCount = urlGen.Count();
            if (totalCount < PerCount)
            {
                Proc(tor);
                return;
            }

            double span = Math.Ceiling(360d / (totalCount / PerCount));
            //double span = 16d;
            App.LogInfo("LagPattern Span:{0}", span);
            _job = new JobTimer(Proc, TimeSpan.FromSeconds(span));
            _job.Start(tor);
            //App.DisposeService.Register(this.GetType(), this);
            lock (Set)
            {
                Set.Add(this);
            }
        }

        protected override void DisposeInternal(bool disposing)
        {
            if (disposing)
            {
                if (_job != null)
                {
                    _job.Dispose();
                }
                //App.DisposeService.Release(this.GetType(), this);
                lock (Set)
                {
                    Set.Remove(this);
                }
            }
        }

        private void Proc(object state)
        {
            var wrap = this.Weak;
            var urlGen = (IEnumerator<string>)state;
            for (int i = 0; i < PerCount; i++)
            {
                if (!urlGen.MoveNext())
                {
                    this.Dispose();
                    return;
                }
                wrap.PushUrl(new Uri(urlGen.Current), _depth, _state);
            }
        }
    }
}