计算NHibernate在单元测试中执行的查询次数

Question

在代码的某些单元/集成测试中,我们希望检查我们的代码是否正在使用二级缓存.

根据Ayende提供的代码:

http://ayende.com/Blog/archive/2006/09/07/MeasuringNHibernatesQueriesPerPage.aspx

我写了一个简单的类来做到这一点:

public class QueryCounter : IDisposable
{
    CountToContextItemsAppender _appender;

    public int QueryCount
    {
      get { return _appender.Count; }
    }

    public void Dispose()
    {
      var logger = (Logger) LogManager.GetLogger("NHibernate.SQL").Logger;
      logger.RemoveAppender(_appender);
    }

    public static QueryCounter Start()
    {
      var logger = (Logger) LogManager.GetLogger("NHibernate.SQL").Logger;

      lock (logger)
      {
        foreach (IAppender existingAppender in logger.Appenders)
        {
          if (existingAppender is CountToContextItemsAppender)
          {
            var countAppender = (CountToContextItemsAppender) existingAppender;

            countAppender.Reset();

            return new QueryCounter {_appender = (CountToContextItemsAppender) existingAppender};
          }
        }

        var newAppender = new CountToContextItemsAppender();
        logger.AddAppender(newAppender);
        logger.Level = Level.Debug;
        logger.Additivity = false;

        return new QueryCounter {_appender = newAppender};
      }
    }

    public class CountToContextItemsAppender : IAppender
    {
      int _count;

      public int Count
      {
        get { return _count; }
      }

      public void Close()
      {
      }

      public void DoAppend(LoggingEvent loggingEvent)
      {
        if (string.Empty.Equals(loggingEvent.MessageObject)) return;
        _count++;
      }

      public string Name { get; set; }

      public void Reset()
      {
        _count = 0;
      }
    }
}

预期用途:

using (var counter = QueryCounter.Start())
{
  // ... do something 
  Assert.Equal(1, counter.QueryCount); // check the query count matches our expectations
}

但它总是为查询计数返回0.没有记录sql语句.

但是,如果我使用Nhibernate Profiler并在我的测试用例中调用它:

NHibernateProfiler.Intialize()

NHProf使用类似的方法从NHibernate捕获日志输出以通过log4net等进行分析,然后我的QueryCounter开始工作.

它看起来像我的思念在我的代码的东西得到log4net的用于记录NHibernate的SQL正确配置......没有任何人有上还有什么我需要做的,从NHibernate的获得SQL日志输出任何指针？

附加信息:

Logging.config:

<log4net>

  <appender name="trace" type="log4net.Appender.TraceAppender, log4net">
    <layout type="log4net.Layout.PatternLayout,log4net">
      <param name="ConversionPattern" value="%d [%t] %-5p %c [%x] &amp;lt;%P{user}&amp;gt; - %m%n" />
    </layout>
  </appender>

  <appender name="console" type="log4net.Appender.ConsoleAppender, log4net">
    <layout type="log4net.Layout.PatternLayout,log4net">
      <param name="ConversionPattern" value="%d [%t] %-5p %c [%x] &amp;lt;%P{user}&amp;gt; - %m%n" />
    </layout>
  </appender>

  <appender name="debug" type="log4net.Appender.DebugAppender, log4net">
    <layout type="log4net.Layout.PatternLayout,log4net">
      <param name="ConversionPattern" value="%d [%t] %-5p %c [%x] &amp;lt;%P{user}&amp;gt; - %m%n" />
    </layout>
  </appender>

  <logger name="NHibernate.SQL" additivity="false">
    <level value="DEBUG" />
    <appender-ref ref="ConsoleAppender" />
  </logger>

  <root>
    <priority value="DEBUG" />
    <appender-ref ref="trace" />
    <appender-ref ref="console" />
    <appender-ref ref="debug" />
  </root>

</log4net>

show_sql:true

基于jfneis响应,我写了一个更简单的类,它只使用NHibernate的工厂统计信息:

public class QueryCounter
{
  long _startCount;

  QueryCounter()
  {
  }

  public int QueryCount
  {
    get { return (int) (UnitOfWork.CurrentSession.SessionFactory.Statistics.QueryExecutionCount - _startCount); }
  }

  public static QueryCounter Start()
  {
    return new QueryCounter {_startCount = UnitOfWork.CurrentSession.SessionFactory.Statistics.QueryExecutionCount};
  }
}

一旦启用统计信息,哪个工作正常.

Answer 1

还有另一种(更简单的,IMO)方式来断言是否正在命中缓存或者正在执行查询:使用统计信息.

首先,您必须在NH配置文件中启用统计信息:

 <property name="generate_statistics">true</property>

之后,您可以随时询问您的会话工厂.你已经谈到了L2缓存测试,所以你可以有类似的东西:

        // act
        MappedEntity retrievedEntity = session.FindById(entity.Id);
        long preCacheCount = sessionFactory.Statistics.SecondLevelCacheHitCount;
        retrievedEntity = session.FindById(entity.Id);
        long postCacheCount = sessionFactory.Statistics.SecondLevelCacheHitCount;
        // assert
        Assert.AreEqual(preCacheCount + 1, postCacheCount);

但是,如果您真正想要的是查询计数,那么Statistics界面中还有很多其他选项:

        sessionFactory.Statistics.QueryExecutionCount;
        sessionFactory.Statistics.TransactionCount;

嗯,就是这样.希望这可以帮助你帮助我.

问候,

菲利佩