Enterprise Library Test Guide - Willy .Net

Using the Test Cases 241
use reflection. The following code shows the SymmetricAlgorithmInstrumentation-
Binder class, which implements the IExplicitInstrumentationBinder interface.
public class SymmetricAlgorithmInstrumentationBinder : IExplicitInstrumentation-
Binder
{
public void Bind(object source, object listener)
{
SymmetricAlgorithmInstrumentationListener castedListener = (SymmetricAlgor
ithmInstrumentationListener)listener;
SymmetricAlgorithmInstrumentationProvider castedProvider = (SymmetricAlgor
ithmInstrumentationProvider)source;
castedProvider.cyptographicOperationFailed += castedListener.Cyptographic-
OperationFailed;
castedProvider.symmetricDecryptionPerformed+= castedListener.SymmetricDecryptionPerformed;
castedProvider.symmetricEncryptionPerformed += castedListener.SymmetricEncryptionPerformed;
}
}
Verification
Running the two test cases again after applying the preceding code verified that the
cost of creating the instrumentation objects was within acceptable limits.
Determining the Cost of Creating Objects Using the FileConfigurationSource Class
Another example of a general performance test is the cost of creating objects with
data contained in a configuration file as opposed to data that is in memory. The
following example uses the Data Access Application Block to determine the cost of
creating a domain object from data in the file configuration source. To pass the test,
the cost of creating domain objects with the FileConfigurationSource class could be
slightly more than when using the SystemConfigurationSource class.
Test Cases
Two test cases determined the cost of creating domain objects with the FileConfigurationSource
class. One test created a Database object with the DatabaseProviderFactory
class and used the FileConfigurationSource class to retrieve the
configuration data from a file. The other test did the same but used the SystemConfigurationSource
class to retrieve the data from memory. Comparing the results
showed whether the application block’s performance was acceptable.
Problems
The results from the performance tests showed that it was more expensive to create a
Database object with the FileConfigurationSource class than to create one with the
SystemConfigurationSource class. An analysis of the application block revealed that
the FileConfigurationSource class read the appropriate sections from the configuration
file each time it created a Database object. This increased the number of I/O
operations and impacted the application block’s performance.