Linq为什么慢？

问题描述

嗨！


测试som Linq-expressions并尝试测量性能和

将它与Linq之前的编程进行比较。


以下两种方法功能相同，但非Linq方法的价格是

的两倍。


public List< ConferenceRoomOldWay（int minimumSeatingCapacity）

{

列表< ConferenceRoomavailableRooms =新列表< ConferenceRoom>（）;


foreach（会议室房间）

{

if（room.SeatingCapacity> = minimumSeatingCapacity）

availableRooms.Add（room）;

}


返回可用房间;

}


公共列表< ConferenceRoomNewWay（int minimumSeatingCapacity）

{

返回（从房间的房间

，其中room.SeatingCapacity> = minimumSeatingCapacity

选择房间）.ToList（）;

}


PS。

简单明了：


达teTime start = DateTime.Now;

for（int i = 0;我< 1000000; i ++）

rooms.OldWay（8）;


Console.WriteLine（（DateTime.Now - start）.Ticks）;


....来衡量表现（一遍又一遍地重复测试）。


结果：

非Linq：约6 300 000蜱

Linq：ca。 3 100 000


为什么Linq更慢？


谢谢

/ Paul

解决方案

我在这里缺少什么？更少的嘀嗒声实际上意味着它更快，对吧？


-Jeroen

我在这里缺少什么？更少的蜱真的意味着它更快，对吧？


-Jeroen

Hi!

Testing som Linq-expressions and tried to measure performance and
compare it to pre-Linq programming.

The folloing two methods are functional equal but the non-Linq one is
twice as fast.

public List<ConferenceRoomOldWay(int minimumSeatingCapacity)
{
List<ConferenceRoomavailableRooms = new List<ConferenceRoom>();

foreach (ConferenceRoom room in rooms)
{
if (room.SeatingCapacity >= minimumSeatingCapacity)
availableRooms.Add(room);
}

return availableRooms;
}

public List<ConferenceRoomNewWay(int minimumSeatingCapacity)
{
return (from room in rooms
where room.SeatingCapacity >= minimumSeatingCapacity
select room).ToList();
}

PS.
Just did a plain and simple:

DateTime start = DateTime.Now;
for (int i = 0; i < 1000000; i++)
rooms.OldWay(8);

Console.WriteLine((DateTime.Now - start).Ticks);

....to mesaure the performance (Did repeate the test over and over).

Results:
Non-Linq: ca. 6 300 000 ticks
Linq: ca. 3 100 000

Why is Linq slower?

Thanks
/Paul

解决方案

What am I missing here? Less ticks actually means it''s faster, right?

-Jeroen

What am I missing here? Less ticks actually means it''s faster, right?

-Jeroen

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