(转)Transaction与OpenCloseTransaction效率分析_卡卡尼莫

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(转)Transaction与OpenCloseTransaction效率分析

(2010-12-08 22:04:11)

标签：

杂谈

分类： C#-AutoCAD

www.objectarx.net 忽悠悠原创,转载请注明.
前些天在群里讨论到Transaction读写实体的效率问题,今天就做了一段代码说明一下
Transaction的效率.Transaction是什么东西这里就不做讨论了,有兴趣的朋友可以在论坛里面搜索以前的帖子.
Transaction有一个子类,叫做OpenCloseTransation,在文档中这样描述它
This class may be used instead of the transaction class in certain scenarios..It wraps the ObjectId.Open/Close functions, but makes it easier to correctly pair these functions by storing references to every object opened and automatically closing them.

也就是说在对实体进行打开关闭操作的时候,它可以替代Transaction类.
我们通过下面代码来测试OpenCloseTransation和Transaction的效率上的区别.

      [CommandMethod("GetTransTime")]
      public void GetTransTime()
      {
         Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
         Stopwatch watch = new Stopwatch();
         PromptSelectionResult res = ed.SelectAll();
         if (res.Status != PromptStatus.OK)
         {
            return;
         }
         ed.WriteMessage("\nCount of entities : {0}", res.Value.Count.ToString());

         watch.Start();
         using (Transaction trans = HostApplicationServices.WorkingDatabase.TransactionManager.StartTransaction())
         {
            foreach (ObjectId id in res.Value.GetObjectIds())
            {
                  Entity ent = trans.GetObject(id, OpenMode.ForWrite) as Entity;
                  ent.ColorIndex = 1;
            }
            trans.Commit();
         }
         watch.Stop();
         ed.WriteMessage("\nOne Transaction write cost: {0}(ms)", watch.ElapsedMilliseconds.ToString());

         watch.Reset();
         watch.Start();
         using (Transaction trans = HostApplicationServices.WorkingDatabase.TransactionManager.StartTransaction())
         {
            foreach (ObjectId id in res.Value.GetObjectIds())
            {
                  Entity ent = trans.GetObject(id, OpenMode.ForRead) as Entity;
                  int nColor = ent.ColorIndex;
            }
         }
         watch.Stop();
         ed.WriteMessage("\nOne Transaction read cost: {0}(ms)", watch.ElapsedMilliseconds.ToString());

         watch.Reset();
         watch.Start();
         using (OpenCloseTransaction trans = HostApplicationServices.WorkingDatabase.TransactionManager.StartOpenCloseTransaction())
         {
            foreach (ObjectId id in res.Value.GetObjectIds())
            {
                  Entity ent = trans.GetObject(id, OpenMode.ForWrite) as Entity;
                  ent.ColorIndex = 2;
            }
            trans.Commit();
         }
         watch.Stop();
         ed.WriteMessage("\nOne OpenCloseTransaction write cost: {0}(ms)", watch.ElapsedMilliseconds.ToString());

         watch.Reset();
         watch.Start();
         using(OpenCloseTransaction trans = HostApplicationServices.WorkingDatabase.TransactionManager.StartOpenCloseTransaction())
         {
            foreach (ObjectId id in res.Value.GetObjectIds())
            {
                  Entity ent = trans.GetObject(id, OpenMode.ForRead) as Entity;
                  int nColor = ent.ColorIndex;
            }
         }
         watch.Stop();
         ed.WriteMessage("\nOne OpenCloseTransaction read cost: {0}(ms)", watch.ElapsedMilliseconds.ToString());

         watch.Reset();
         watch.Start();
         foreach (ObjectId id in res.Value.GetObjectIds())
         {
            using (OpenCloseTransaction trans = HostApplicationServices.WorkingDatabase.TransactionManager.StartOpenCloseTransaction())
            {
                  Entity ent = trans.GetObject(id, OpenMode.ForRead) as Entity;
                  int nColor = ent.ColorIndex;
            }
         }
         watch.Stop();
         ed.WriteMessage("\nMulty OpenCloseTransaction read cost: {0}(ms)", watch.ElapsedMilliseconds.ToString());

         watch.Reset();
         watch.Start();
         foreach (ObjectId id in res.Value.GetObjectIds())
         {
            using (Transaction trans = HostApplicationServices.WorkingDatabase.TransactionManager.StartTransaction())
            {
                  Entity ent = trans.GetObject(id, OpenMode.ForRead) as Entity;
                  int nColor = ent.ColorIndex;
            }
         }
         watch.Stop();
         ed.WriteMessage("\nMulty Transaction read cost: {0}(ms)", watch.ElapsedMilliseconds.ToString());
      }

上述代码在VS 2010 + Civil3d 2010中对于两张图形的运行结果如下

命令: GetTransTime
Count of entities : 7260
One Transaction write cost: 212(ms)
One Transaction read cost: 23(ms)
One OpenCloseTransaction write cost: 143(ms)
One OpenCloseTransaction read cost: 20(ms)
Multy OpenCloseTransaction read cost: 33(ms)
Multy Transaction read cost: 11707(ms)

命令: GetTransTimeCount of entities : 14520
One Transaction write cost: 388(ms)
One Transaction read cost: 38(ms)
One OpenCloseTransaction write cost: 295(ms)
One OpenCloseTransaction read cost: 39(ms)
Multy OpenCloseTransaction read cost: 69(ms)
Multy Transaction read cost: 18186(ms)

我们由此可以得到一个结论,OpenCloseTransation对于处理实体的读操作,效率比Transaction要高很多,
特别是需要处理多个事务时,效率提升更加明显.并且,一次一个Transaction处理多个实体,比每个实体新建一个Transaction效率要高的多.

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