using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Threading;
using Danny.Infrastructure.Helper;
namespace Danny.Infrastructure.Collections
{
/// <summary>
/// 一个基于BlockingCollection实现的多线程的处理队列
/// </summary>
public class ProcessQueue<T>
{
private BlockingCollection<T> _queue;
private CancellationTokenSource _cancellationTokenSource;
private CancellationToken _cancellToken;
//内部线程池
private List<Thread> _threadCollection;
//队列是否正在处理数据
private int _isProcessing;
//有线程正在处理数据
private const int Processing = 1;
//没有线程处理数据
private const int UnProcessing = 0;
//队列是否可用
private volatile bool _enabled = true;
//内部处理线程数量
private int _internalThreadCount;
public event Action<T> ProcessItemEvent;
//处理异常,需要三个参数,当前队列实例,异常,当时处理的数据
public event Action<dynamic,Exception,T> ProcessExceptionEvent;
public ProcessQueue()
{
_queue=new BlockingCollection<T>();
_cancellationTokenSource = new CancellationTokenSource();
_internalThreadCount = 1;
_cancellToken = _cancellationTokenSource.Token;
_threadCollection = new List<Thread>();
}
public ProcessQueue(int internalThreadCount):this()
{
this._internalThreadCount = internalThreadCount;
}
/// <summary>
/// 队列内部元素的数量
/// </summary>
public int GetInternalItemCount()
{
return _queue.Count;
}
public void Enqueue(T items)
{
if (items == null)
{
throw new ArgumentException("items");
}
_queue.Add(items);
DataAdded();
}
public void Flush()
{
StopProcess();
while (_queue.Count != 0)
{
T item=default(T);
if (_queue.TryTake(out item))
{
try
{
ProcessItemEvent(item);
}
catch (Exception ex)
{
OnProcessException(ex,item);
}
}
}
}
private void DataAdded()
{
if (_enabled)
{
if (!IsProcessingItem())
{
ProcessRangeItem();
StartProcess();
}
}
}
//判断是否队列有线程正在处理
private bool IsProcessingItem()
{
return !(Interlocked.CompareExchange(ref _isProcessing, Processing, UnProcessing) == UnProcessing);
}
private void ProcessRangeItem()
{
for (int i = 0; i < this._internalThreadCount; i++)
{
ProcessItem();
}
}
private void ProcessItem()
{
Thread currentThread = new Thread((state) =>
{
T item=default(T);
while (_enabled)
{
try
{
try
{
item = _queue.Take(_cancellToken);
ProcessItemEvent(item);
}
catch (OperationCanceledException ex)
{
DebugHelper.DebugView(ex.ToString());
}
}
catch (Exception ex)
{
OnProcessException(ex,item);
}
}
});
_threadCollection.Add(currentThread);
}
private void StartProcess()
{
foreach (var thread in _threadCollection)
{
thread.Start();
}
}
private void StopProcess()
{
this._enabled = false;
foreach (var thread in _threadCollection)
{
if (thread.IsAlive)
{
thread.Join();
}
}
_threadCollection.Clear();
}
private void OnProcessException(Exception ex,T item)
{
var tempException = ProcessExceptionEvent;
Interlocked.CompareExchange(ref ProcessExceptionEvent, null, null);
if (tempException != null)
{
ProcessExceptionEvent(this,ex,item);
}
}
}
}
class Program
{
static void Main(string[] args)
{
ProcessQueue<int> processQueue = new ProcessQueue<int>();
processQueue.ProcessExceptionEvent += ProcessQueue_ProcessExceptionEvent;
processQueue.ProcessItemEvent += ProcessQueue_ProcessItemEvent;
processQueue.Enqueue(1);
processQueue.Enqueue(2);
processQueue.Enqueue(3);
}
/// <summary>
/// 该方法对入队的每个元素进行处理
/// </summary>
/// <param name="value"></param>
private static void ProcessQueue_ProcessItemEvent(int value)
{
Console.WriteLine(value);
}
/// <summary>
/// 处理异常
/// </summary>
/// <param name="obj">队列实例</param>
/// <param name="ex">异常对象</param>
/// <param name="value">出错的数据</param>
private static void ProcessQueue_ProcessExceptionEvent(dynamic obj, Exception ex, int value)
{
Console.WriteLine(ex.ToString());
}
}