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• Messaging Systems – Handshaking, Reconciliation and Tracking for Data Transparency

  - by Ahsan Alam

  As many corporations build business partnerships with other organizations, the need to share information becomes necessary. Large amount of data sharing using snail mail, email and/or fax are quickly becoming a thing of the past. More and more organizations are relying heavily on Ftp and/or Web Service to exchange data. Corporations apply wide range of technologies and techniques based on available resources and data transfer needs. Sometimes, it involves simple home-grown applications. Other times, large investments are made on products like BizTalk, TIBCO etc. Complexity of information management also varies significantly from one organizations to another. Some may deal with handful of simple steps to process and manage shared data; whereas others may rely on fairly complex processes with heavy interaction with internal and external systems in order to serve the business needs. It is not surprising that many of these systems end up becoming black boxes over a period of time. Consequently, people and business start to rely more and more on developers and support personnel just to extract simple information adding to the loss of productivity. One of the most important factor in any business is transparency to data irrespective of technology preferences and the complexity of business processes. Not knowing the state of data could become very costly to the business. Being involved in messaging systems for some time now, I have heard the same type of questions over and over again. Did we transmit messages successfully? Did we get responses back? What is the expected turn-around-time? Did the system experience any errors? When one company transmits data to one or more company, it may invoke a set of processes that could complete in matter of seconds, or it could days. As data travels from one organizations to another, the uncertainty grows, and the longer it takes to track uncertain state of the data the costlier it gets for the business, So, in every business scenario, it's extremely important to be aware of the state of the data.   Architects of messaging systems can take several steps to aid with data transparency. Some forms of data handshaking and reconciliation mechanism as well as extensive data tracking can be incorporated into the system to provide clear visibility to the data. What do I mean by handshaking and reconciliation? Some might consider these to be a single concept; however, I like to consider them in two unique categories. Handshaking serves as message receipts or acknowledgment. When one transmits messages to another, the receiver must acknowledge each message by sending immediate responses for each transaction. Whenever we use Web Services, handshaking is often achieved utilizing request/reply pattern. Similarly, if Ftp is used, a receiver can acknowledge by dropping messages for the sender as soon as the files are picked up. These forms of handshaking or acknowledgment informs the message sender and receiver that a successful transaction has occurred. I have mentioned earlier that it could take anywhere from a few seconds to a number of days before shared data is completely processed. In addition, whenever a batched transaction is used, processing time for each data element inside the batch could also vary significantly. So, in order to successfully manage data processing, reconciliation becomes extremely important; otherwise it may result into data loss or in some cases hefty penalty. Reconciliation can be done in many ways. Partner organizations can share and compare ad hoc reports to achieve reconciliation. On the other hand, partners can agree on some type of systematic reconciliation messages. Systems within responsible parties can trigger messages to partners as soon as the data process completes.   Next step in the data transparency is extensive data tracking. Some products such as BizTalk and TIBCO provide built-in functionality for data tracking; however, built-in functionality may not always be adequate. Sometimes additional tracking system (or databases) needs to be built in order monitor all types of data flow including, message transactions, handshaking, reconciliation, system errors and many more. If these types of data are captured, then these can be presented to business users in any forms or fashion. When business users are empowered with such information, then the reliance on developers and support teams decreases dramatically.   In today's collaborative world of information sharing, data transparency is key to the success of every business. The state of business data will constantly change. However, when people have easier access to various states of data, it allows them to make better and quicker decisions. Therefore, I feel that data handshaking, reconciliation and tracking is very important aspect of messaging systems.

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• ASP.NET MVC 3 Hosting :: Rolling with Razor in MVC v3 Preview

  - by mbridge

  Razor is an alternate view engine for asp.net MVC.  It was introduced in the “WebMatrix” tool and has now been released as part of the asp.net MVC 3 preview 1.  Basically, Razor allows us to replace the clunky <% %> syntax with a much cleaner coding model, which integrates very nicely with HTML.  Additionally, it provides some really nice features for master page type scenarios and you don’t lose access to any of the features you are currently familiar with, such as HTML helper methods. First, download and install the ASP.NET MVC Preview 1.  You can find this at http://www.microsoft.com/downloads/details.aspx?FamilyID=cb42f741-8fb1-4f43-a5fa-812096f8d1e8&displaylang=en. Now, follow these steps to create your first asp.net mvc project using Razor: 1. Open Visual Studio 2010 2. Create a new project.  Select File->New->Project (Shift Control N) 3. You will see the list of project types which should look similar to what’s shown:   4. Select “ASP.NET MVC 3 Web Application (Razor).”  Set the application name to RazorTest and the path to c:projectsRazorTest for this tutorial. If you select accidently select ASPX, you will end up with the standard asp.net view engine and template, which isn’t what you want. 5. For this tutorial, and ONLY for this tutorial, select “No, do not create a unit test project.”  In general, you should create and use a unit test project.  Code without unit tests is kind of like diet ice cream.  It just isn’t very good. Now, once we have this done, our brand new project will be created.    In all likelihood, Visual Studio will leave you looking at the “HomeController.cs” class, as shown below: Immediately, you should notice one difference.  The Index action used to look like: public ActionResult Index () { ViewData[“Message”] = “Welcome to ASP.Net MVC!”; Return View(); } While this will still compile and run just fine, ASP.Net MVC 3 has a much nicer way of doing this: public ActionResult Index() { ViewModel.Message = “Welcome to ASP.Net MVC!”; Return View(); } Instead of using ViewData we are using the new ViewModel object, which uses the new dynamic data typing of .Net 4.0 to allow us to express ourselves much more cleanly.  This isn’t a tutorial on ALL of MVC 3, but the ViewModel concept is one we will need as we dig into Razor. What comes in the box? When we create a project using the ASP.Net MVC 3 Template with Razor, we get a standard project setup, just like we did in ASP.NET MVC 2.0 but with some differences.  Instead of seeing “.aspx” view files and “.ascx” files, we see files with the “.cshtml” which is the default razor extension.  Before we discuss the details of a razor file, one thing to keep in mind is that since this is an extremely early preview, intellisense is not currently enabled with the razor view engine.  This is promised as an updated before the final release.  Just like with the aspx view engine, the convention of the folder name for a set of views matching the controller name without the word “Controller” still stands.  Similarly, each action in the controller will usually have a corresponding view file in the appropriate view directory.  Remember, in asp.net MVC, convention over configuration is key to successful development! The initial template organizes views in the following folders, located in the project under Views: - Account – The default account management views used by the Account controller.  Each file represents a distinct view. - Home – Views corresponding to the appropriate actions within the home controller. - Shared – This contains common view objects used by multiple views.  Within here, master pages are stored, as well as partial page views (user controls).  By convention, these partial views are named “_XXXPartial.cshtml” where XXX is the appropriate name, such as _LogonPartial.cshtml.  Additionally, display templates are stored under here. With this in mind, let us take a look at the index.cshtml file under the home view directory.  When you open up index.cshtml you should see 1:   @inherits System.Web.Mvc.WebViewPage 2:  @{ 3:          View.Title = "Home Page"; 4:       LayoutPage = "~/Views/Shared/_Layout.cshtml"; 5:   } 6:  <h2>@View.Message</h2> 7:  <p> 8:     To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc" title="ASP.NET MVC     9:    Website">http://asp.net/mvc</a>. 10:  </p> So looking through this, we observe the following facts: Line 1 imports the base page that all views (using Razor) are based on, which is System.Web.Mvc.WebViewPage.  Note that this is different than System.Web.MVC.ViewPage which is used by asp.net MVC 2.0 Also note that instead of the <% %> syntax, we use the very simple ‘@’ sign.  The View Engine contains enough context sensitive logic that it can even distinguish between @ in code and @ in an email.  It’s a very clean markup.  Line 2 introduces the idea of a code block in razor.  A code block is a scoping mechanism just like it is in a normal C# class.  It is designated by @{… }  and any C# code can be placed in between.  Note that this is all server side code just like it is when using the aspx engine and <% %>.  Line 3 allows us to set the page title in the client page’s file.  This is a new feature which I’ll talk more about when we get to master pages, but it is another of the nice things razor brings to asp.net mvc development. Line 4 is where we specify our “master” page, but as you can see, you can place it almost anywhere you want, because you tell it where it is located.  A Layout Page is similar to a master page, but it gains a bit when it comes to flexibility.  Again, we’ll come back to this in a later installment.  Line 6 and beyond is where we display the contents of our view.  No more using <%: %> intermixed with code.  Instead, we get to use very clean syntax such as @View.Message.  This is a lot easier to read than <%:@View.Message%> especially when intermixed with html.  For example: <p> My name is @View.Name and I live at @View.Address </p> Compare this to the equivalent using the aspx view engine <p> My name is <%:View.Name %> and I live at <%: View.Address %> </p> While not an earth shaking simplification, it is easier on the eyes.  As  we explore other features, this clean markup will become more and more valuable.

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• Using the Static Code Analysis feature of Visual Studio (Premium/Ultimate) to find memory leakage problems

  - by terje

  Memory for managed code is handled by the garbage collector, but if you use any kind of unmanaged code, like native resources of any kind, open files, streams and window handles, your application may leak memory if these are not properly handled.  To handle such resources the classes that own these in your application should implement the IDisposable interface, and preferably implement it according to the pattern described for that interface. When you suspect a memory leak, the immediate impulse would be to start up a memory profiler and start digging into that.   However, before you follow that impulse, do a Static Code Analysis run with a ruleset tuned to finding possible memory leaks in your code.  If you get any warnings from this, fix them before you go on with the profiling. How to use a ruleset In Visual Studio 2010 (Premium and Ultimate editions) you can define your own rulesets containing a list of Static Code Analysis checks.   I have defined the memory checks as shown in the lists below as ruleset files, which can be downloaded – see bottom of this post.  When you get them, you can easily attach them to every project in your solution using the Solution Properties dialog. Right click the solution, and choose Properties at the bottom, or use the Analyze menu and choose “Configure Code Analysis for Solution”: In this dialog you can now choose the Memorycheck ruleset for every project you want to investigate.  Pressing Apply or Ok opens every project file and changes the projects code analysis ruleset to the one we have specified here. How to define your own ruleset  (skip this if you just download my predefined rulesets) If you want to define the ruleset yourself, open the properties on any project, choose Code Analysis tab near the bottom, choose any ruleset in the drop box and press Open Clear out all the rules by selecting “Source Rule Sets” in the Group By box, and unselect the box Change the Group By box to ID, and select the checks you want to include from the lists below. Note that you can change the action for each check to either warning, error or none, none being the same as unchecking the check.   Now go to the properties window and set a new name and description for your ruleset. Then save (File/Save as) the ruleset using the new name as its name, and use it for your projects as detailed above. It can also be wise to add the ruleset to your solution as a solution item. That way it’s there if you want to enable Code Analysis in some of your TFS builds.   Running the code analysis In Visual Studio 2010 you can either do your code analysis project by project using the context menu in the solution explorer and choose “Run Code Analysis”, you can define a new solution configuration, call it for example Debug (Code Analysis), in for each project here enable the Enable Code Analysis on Build   In Visual Studio Dev-11 it is all much simpler, just go to the Solution root in the Solution explorer, right click and choose “Run code analysis on solution”.     The ruleset checks The following list is the essential and critical memory checks.  CheckID Message Can be ignored ? Link to description with fix suggestions CA1001 Types that own disposable fields should be disposable No  http://msdn.microsoft.com/en-us/library/ms182172.aspx CA1049 Types that own native resources should be disposable Only if the pointers assumed to point to unmanaged resources point to something else  http://msdn.microsoft.com/en-us/library/ms182173.aspx CA1063 Implement IDisposable correctly No  http://msdn.microsoft.com/en-us/library/ms244737.aspx CA2000 Dispose objects before losing scope No  http://msdn.microsoft.com/en-us/library/ms182289.aspx CA2115 1 Call GC.KeepAlive when using native resources See description  http://msdn.microsoft.com/en-us/library/ms182300.aspx CA2213 Disposable fields should be disposed If you are not responsible for release, of if Dispose occurs at deeper level  http://msdn.microsoft.com/en-us/library/ms182328.aspx CA2215 Dispose methods should call base class dispose Only if call to base happens at deeper calling level  http://msdn.microsoft.com/en-us/library/ms182330.aspx CA2216 Disposable types should declare a finalizer Only if type does not implement IDisposable for the purpose of releasing unmanaged resources  http://msdn.microsoft.com/en-us/library/ms182329.aspx CA2220 Finalizers should call base class finalizers No  http://msdn.microsoft.com/en-us/library/ms182341.aspx Notes: 1) Does not result in memory leak, but may cause the application to crash   The list below is a set of optional checks that may be enabled for your ruleset, because the issues these points too often happen as a result of attempting to fix up the warnings from the first set.   ID Message Type of fault Can be ignored ? Link to description with fix suggestions CA1060 Move P/invokes to NativeMethods class Security No http://msdn.microsoft.com/en-us/library/ms182161.aspx CA1816 Call GC.SuppressFinalize correctly Performance Sometimes, see description http://msdn.microsoft.com/en-us/library/ms182269.aspx CA1821 Remove empty finalizers Performance No http://msdn.microsoft.com/en-us/library/bb264476.aspx CA2004 Remove calls to GC.KeepAlive Performance and maintainability Only if not technically correct to convert to SafeHandle http://msdn.microsoft.com/en-us/library/ms182293.aspx CA2006 Use SafeHandle to encapsulate native resources Security No http://msdn.microsoft.com/en-us/library/ms182294.aspx CA2202 Do not dispose of objects multiple times Exception (System.ObjectDisposedException) No http://msdn.microsoft.com/en-us/library/ms182334.aspx CA2205 Use managed equivalents of Win32 API Maintainability and complexity Only if the replace doesn’t provide needed functionality http://msdn.microsoft.com/en-us/library/ms182365.aspx CA2221 Finalizers should be protected Incorrect implementation, only possible in MSIL coding No http://msdn.microsoft.com/en-us/library/ms182340.aspx   Downloadable ruleset definitions I have defined three rulesets, one called Inmeta.Memorycheck with the rules in the first list above, and Inmeta.Memorycheck.Optionals containing the rules in the second list, and the last one called Inmeta.Memorycheck.All containing the sum of the two first ones.  All three rulesets can be found in the  zip archive  “Inmeta.Memorycheck” downloadable from here.   Links to some other resources relevant to Static Code Analysis MSDN Magazine Article by Mickey Gousset on Static Code Analysis in VS2010 MSDN :  Analyzing Managed Code Quality by Using Code Analysis, root of the documentation for this Preventing generated code from being analyzed using attributes Online training course on Using Code Analysis with VS2010 Blogpost by Tatham Oddie on custom code analysis rules How to write custom rules, from Microsoft Code Analysis Team Blog Microsoft Code Analysis Team Blog

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• Getting Started with Prism (aka Composite Application Guidance for WPF and Silverlight)

  - by dotneteer

  Overview Prism is a framework from the Microsoft Patterns and Practice team that allow you to create WPF and Silverlight in a modular way. It is especially valuable for larger projects in which a large number of developers can develop in parallel. Prism achieves its goal by supplying several services: · Dependency Injection (DI) and Inversion of control (IoC): By using DI, Prism takes away the responsibility of instantiating and managing the life time of dependency objects from individual components to a container. Prism relies on containers to discover, manage and compose large number of objects. By varying the configuration, the container can also inject mock objects for unit testing. Out of the box, Prism supports Unity and MEF as container although it is possible to use other containers by subclassing the Bootstrapper class. · Modularity and Region: Prism supplies the framework to split application into modules from the application shell. Each module is a library project that contains both UI and code and is responsible to initialize itself when loaded by the shell. Each window can be further divided into regions. A region is a user control with associated model. · Model, view and view-model (MVVM) pattern: Prism promotes the user MVVM. The use of DI container makes it much easier to inject model into view. WPF already has excellent data binding and commanding mechanism. To be productive with Prism, it is important to understand WPF data binding and commanding well. · Event-aggregation: Prism promotes loosely coupled components. Prism discourages for components from different modules to communicate each other, thus leading to dependency. Instead, Prism supplies an event-aggregation mechanism that allows components to publish and subscribe events without knowing each other. Architecture In the following, I will go into a little more detail on the services provided by Prism. Bootstrapper In a typical WPF application, application start-up is controls by App.xaml and its code behind. The main window of the application is typically specified in the App.xaml file. In a Prism application, we start a bootstrapper in the App class and delegate the duty of main window to the bootstrapper. The bootstrapper will start a dependency-injection container so all future object instantiations are managed by the container. Out of box, Prism provides the UnityBootstrapper and MefUnityBootstrapper abstract classes. All application needs to either provide a concrete implementation of one of these bootstrappers, or alternatively, subclass the Bootstrapper class with another DI container. A concrete bootstrapper class must implement the CreateShell method. Its responsibility is to resolve and create the Shell object through the DI container to serve as the main window for the application. The other important method to override is ConfigureModuleCatalog. The bootstrapper can register modules for the application. In a more advance scenario, an application does not have to know all its modules at compile time. Modules can be discovered at run time. Readers to refer to one of the Open Modularity Quick Starts for more information. Modules Once modules are registered with or discovered by Prism, they are instantiated by the DI container and their Initialize method is called. The DI container can inject into a module a region registry that implements IRegionViewRegistry interface. The module, in its Initialize method, can then call RegisterViewWithRegion method of the registry to register its regions. Regions Regions, once registered, are managed by the RegionManager. The shell can then load regions either through the RegionManager.RegionName attached property or dynamically through code. When a view is created by the region manager, the DI container can inject view model and other services into the view. The view then has a reference to the view model through which it can interact with backend services. Service locator Although it is possible to inject services into dependent classes through a DI container, an alternative way is to use the ServiceLocator to retrieve a service on demard. Prism supplies a service locator implementation and it is possible to get an instance of the service by calling: ServiceLocator.Current.GetInstance<IServiceType>() Event aggregator Prism supplies an IEventAggregator interface and implementation that can be injected into any class that needs to communicate with each other in a loosely-coupled fashion. The event aggregator uses a publisher/subscriber model. A class can publishes an event by calling eventAggregator.GetEvent<EventType>().Publish(parameter) to raise an event. Other classes can subscribe the event by calling eventAggregator.GetEvent<EventType>().Subscribe(EventHandler, other options). Getting started The easiest way to get started with Prism is to go through the Prism Hands-On labs and look at the Hello World QuickStart. The Hello World QuickStart shows how bootstrapper, modules and region works. Next, I would recommend you to look at the Stock Trader Reference Implementation. It is a more in depth example that resemble we want to set up an application. Several other QuickStarts cover individual Prism services. Some scenarios, such as dynamic module discovery, are more advanced. Apart from the official prism document, you can get an overview by reading Glen Block’s MSDN Magazine article. I have found the best free training material is from the Boise Code Camp. To be effective with Prism, it is important to understands key concepts of WPF well first, such as the DependencyProperty system, data binding, resource, theme and ICommand. It is also important to know your DI container of choice well. I will try to explorer these subjects in depth in the future. Testimony Recently, I worked on a desktop WPF application using Prism. I had a wonderful experience with Prism. The Prism is flexible enough even in the presence of third party controls such as Telerik WPF controls. We have never encountered any significant obstacle.

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• AS11 Oracle B2B Sync Support - Series 2

  - by sinkarbabu.kirubanithi

  In the earlier series, we discussed about how to model "Sync Support" in Oracle B2B. And, we haven't discussed how the response can be consumed synchronously by the back-end application or initiator of sync request. In this sequel, we will see how we can extend it to the SOA composite applications to model the end-to-end usecase, this would help the initiator of sync request to receive the response synchronously. Series 2 - is little lengthier for blog standards so be prepared before you continue further :). Let's start our discussion with a high-level scenario where one need to initiate a synchronous request and get response synchronously. There are various approaches available, we will see one simplest approach here. Components Involved: 1. Oracle B2B 2. Oracle JCA JMS Adapter 3. Oracle BPEL 4. All of the above are wrapped up in a single SOA composite application. Oracle B2B: Skipping the "Sync Support" setup part in B2B, as we have already discussed that in the earlier series 1. Here we have provided "Sync Support" samples that can be imported to B2B directly and users can start testing the same in few minutes. Initiator Sample: This requires two JMS queues to be created, one for B2B to receive initial outbound sync request and the other is for B2B to deliver the incoming sync response to the back-end. Please enable "Use JMS Id" option in both internal listening and delivery channels. This would enable JCA JMS Adapter to correlate the initial B2B request and response and in turn it would be returned as synchronous response of BPEL. Internal Listening Channel Image: Internal Delivery Channel Image: To get going without much challenges, just create queues in Weblogic with the JNDI mentioned in the above two screenshots. If you want to use different names, then you may have to change the queue jndi names in sample after importing it into B2B. Here are the Queue related JNDI names used in the sample, 1. Internal Listening Channel Queue details, Name: JNDI Name: jms/b2b/syncreplyqueue 2. Internal Delivery Channel Queue details, Name: JNDI Name: jms/b2b/syncrequestqueue Here is the Initiator Sample Acme.zip Note: You may have to adjust the ip address of GlobalChips endpoint in the Delivery Channel. Responder Sample: Contains B2B meta-data and the Callout. Just import the sample and place the callout binary under "/tmp/callout" directory. If you choose to use a different location for callout, then you may have to change the same in B2B Configuration after importing the sample. Here are the artifacts, 1. Callout Source SampleCallout.java 2. Callout Binary sample-callout.jar 3. Responder Sample GlobalChips.zip Callout Details: Just gives the static response XML that needs to be sent back as response for the inbound sync request. For a sample purpose, we have given static response but in production you may have to invoke a web service or something similar to get the response. IMPORTANT NOTE: For Sync Support use case, responder is not expected to deliver the inbound sync request to backend as the process of delivering and getting the response from backend are expected from the Callout. This default behavior can be overridden by enabling the config property "b2b.SyncAppDelivery=true" in B2B config mbean (b2b-config.xml). This makes B2B to deliver the inbound sync request to be delivered to backend queue but the response to be sent to remote caller still has to come from Callout. 2. Oracle JCA JMS Adapter: On the initiator side, we have used JCA JMS Request/Reply pattern to send/receive the synchronous message from B2B. 3. Oracle BPEL: Exposes WS-SOAP Endpoint that takes payload as input and passes the same to B2B and returns the synchronous response of B2B as SOAP response. For outside world, it looks as if it is the synchronous web service endpoint but under the cover it uses JMS to trigger/initiate B2B to send and receive the synchronous response. 4. Composite application: All the components discussed above are wired in SOA composite application that helps to model a end-to-end synchronous use case. Here's the composite application sca_B2BSyncSample_rev1.0.jar, you may just deploy this to your AS11 SOA to make use of it. For any editing, you can just import the project in your JDEV under any SOA Application. Here are the composite application screenshots, Composite Application: BPEL With JCA JMS Adapter (Request/Reply):

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• Fusion HCM SaaS – Integration

  - by Kiran Mundy

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Fusion HCM SaaS – Integration A typical implementation pattern we’re seeing with Fusion Apps early adopters is implementing a few Fusion HCM applications that bring the most benefit to their company with the least disruption to existing programs and interfaces. Very often this ends up being Fusion Goals & Performance, Talent, Compensation or Benefits, often with Taleo for recruiting. The implementation picture looks like what you see below: Here, you can see that all the “downstream integrations” from the On-Premise Core HR, are unaffected because the master for employee data is still your On-Premise Core HR system – all updates and new hires are made here (although they may be fed in from Taleo to start with). As a second phase when customers migrate Core HR to Fusion HCM, they have to come up with a strategy to manage integrations to all their downstream applications that require employee details. For customers coming from EBS HR, a short term strategy that allows for minimal impact, is to extract employee data from Fusion (Via HCM Extract), and load the shared EBS HR tables (which are part of an EBS Financials install anyways), and let your downstream integrations continue to function based on this data as shown below. If you are not coming from EBS HR and there are license implications, you may want to consider: Creating an On-Premise warehouse for extracting data from Fusion Apps. Leveraging Fusion Apps Web Services (available to SaaS customers starting R7) to directly retrieve/write data to Fusion Apps. Integration Tools File Based Loader This is the primary mechanism for loading HCM data (both initial load and incremental updates) into Fusion HCM. Employee & related data can be uploaded into Fusion HCM using File Based Loader. Note that ability to schedule File Based Loader to run on a pre-defined schedule will be available as a patch on top of Rel 5. Hr2Hr has been deprecated in favor of File Based Loader, but for existing customers using Hr2Hr, here are some sample scripts that show how to get more informative error messages. They can be run by creating data model sql queries in BI Publisher. The scripts currently have hard coded values for request id and loader batch id, which your developer will need to update to the correct values for you. The BI Publisher Training Session recorded on Apr 18th is available here (under "Recordings"). This will enable a somewhat technical resource to create a data model sql query. Links to Documentation & Traning Reference documentation for File Based Loader on docs.oracle.com FBL 1.1 MOS Doc Id 1533860.1 Sample demo data files for File Based Loader HCM SaaS Integrations ppt and recording. EBS api's Loading Information into EBS Full or Shared HCM This could be candidate information being loaded from Taleo into EBS or  Employee information being loaded from Fusion HCM into an EBS shared HR install (for downstream applications & EBS Financials). Oracle HRMS Product Family Publicly Callable Business Process APIs (A Reference Consolidation) [ID 216838.1] This is a guide to the EBS R12 Integration Repository accessible from an EBS instance. EBS HRMS Publicly Callable Business Process APIs in Release 11i & 12 [ID 121964.1] Fusion HCM Extract Fusion HCM Extract is the primary mechanism used to extract employee information from Fusion HCM. Refer to the "Configure Identity Sync" doc on MOS  for additional mechanisms. Additional documentation (you'll need an oracle.com account to access) HCM Extracts User Guides (Rel 4 & 5) HCM Extract Entity/Attributes (Rel 5) HCM Extract User Guide (Rel 5) If you don’t have an oracle.com account, download the zipped HCM Extract Rel 5 Docs (Click on File --> Download on next screen). View Training Recordings on Fusion HCM Extract Benefits Extract To setup the benefits extract, refer to the following guide. Page 2-15 of the User Documentation describes how to use the benefits extract. Benefit enrollments can also be uploaded into Fusion Benefits. Instructions are here along with a sample upload file. However, if the defined benefits extract does not meet your requirements, you can use BI Publisher (Link to BI Publisher presentation recording from Apr 18th) to create your own version of Benefits extract. You can start with the data model query underlying the benefits extract. Payroll Interface Fusion Payroll Interface enables you to capture personal payroll information, such as earnings and deductions, along with other data from Oracle Fusion Human Capital Management, and send that information to a third-party payroll provider. Documentation: Payroll interface guide Sample file DBI's used for the payroll interface.Usage Patterns always accessible @ http://www.finapps.com Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";}

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• ASP.NET WebAPI Security 2: Identity Architecture

  - by Your DisplayName here!

  Pedro has beaten me to the punch with a detailed post (and diagram) about the WebAPI hosting architecture. So go read his post first, then come back so we can have a closer look at what that means for security. The first important takeaway is that WebAPI is hosting independent-  currently it ships with two host integration implementations – one for ASP.NET (aka web host) and WCF (aka self host). Pedro nicely shows the integration into the web host. Self hosting is not done yet so we will mainly focus on the web hosting case and I will point out security related differences when they exist. The interesting part for security (amongst other things of course) is the HttpControllerHandler (see Pedro’s diagram) – this is where the host specific representation of an HTTP request gets converted to the WebAPI abstraction (called HttpRequestMessage). The ConvertRequest method does the following: Create a new HttpRequestMessage. Copy URI, method and headers from the HttpContext. Copies HttpContext.User to the Properties<string, object> dictionary on the HttpRequestMessage. The key used for that can be found on HttpPropertyKeys.UserPrincipalKey (which resolves to “MS_UserPrincipal”). So the consequence is that WebAPI receives whatever IPrincipal has been set by the ASP.NET pipeline (in the web hosting case). Common questions are: Are there situations where is property does not get set? Not in ASP.NET – the DefaultAuthenticationModule in the HTTP pipeline makes sure HttpContext.User (and Thread.CurrentPrincipal – more on that later) are always set. Either to some authenticated user – or to an anonymous principal. This may be different in other hosting environments (again more on that later). Why so generic? Keep in mind that WebAPI is hosting independent and may run on a host that materializes identity completely different compared to ASP.NET (or .NET in general). This gives them a way to evolve the system in the future. How does WebAPI code retrieve the current client identity? HttpRequestMessage has an extension method called GetUserPrincipal() which returns the property as an IPrincipal. A quick look at self hosting shows that the moral equivalent of HttpControllerHandler.ConvertRequest() is HttpSelfHostServer.ProcessRequestContext(). Here the principal property gets only set when the host is configured for Windows authentication (inconsisteny). Do I like that? Well – yes and no. Here are my thoughts: I like that it is very straightforward to let WebAPI inherit the client identity context of the host. This might not always be what you want – think of an ASP.NET app that consists of UI and APIs – the UI might use Forms authentication, the APIs token based authentication. So it would be good if the two parts would live in a separate security world. It makes total sense to have this generic hand off point for identity between the host and WebAPI. It also makes total sense for WebAPI plumbing code (especially handlers) to use the WebAPI specific identity abstraction. But – c’mon we are running on .NET. And the way .NET represents identity is via IPrincipal/IIdentity. That’s what every .NET developer on this planet is used to. So I would like to see a User property of type IPrincipal on ApiController. I don’t like the fact that Thread.CurrentPrincipal is not populated. T.CP is a well established pattern as a one stop shop to retrieve client identity on .NET.  That makes a lot of sense – even if the name is misleading at best. There might be existing library code you want to call from WebAPI that makes use of T.CP (e.g. PrincipalPermission, or a simple .Name or .IsInRole()). Having the client identity as an ambient property is useful for code that does not have access to the current HTTP request (for calling GetUserPrincipal()). I don’t like the fact that that the client identity conversion from host to WebAPI is inconsistent. This makes writing security plumbing code harder. I think the logic should always be: If the host has a client identity representation, copy it. If not, set an anonymous principal on the request message. Btw – please don’t annoy me with the “but T.CP is static, and static is bad for testing” chant. T.CP is a getter/setter and, in fact I find it beneficial to be able to set different security contexts in unit tests before calling in some logic. And, in case you have wondered – T.CP is indeed thread static (and the name comes from a time where a logical operation was bound to a thread – which is not true anymore). But all thread creation APIs in .NET actually copy T.CP to the new thread they create. This is the case since .NET 2.0 and is certainly an improvement compared to how Win32 does things. So to sum it up: The host plumbing copies the host client identity to WebAPI (this is not perfect yet, but will surely be improved). or in other words: The current WebAPI bits don’t ship with any authentication plumbing, but solely use whatever authentication (and thus client identity) is set up by the host. WebAPI developers can retrieve the client identity from the HttpRequestMessage. Hopefully my proposed changes around T.CP and the User property on ApiController will be added. In the next post, I will detail how to add WebAPI specific authentication support, e.g. for Basic Authentication and tokens. This includes integrating the notion of claims based identity. After that we will look at the built-in authorization bits and how to improve them as well. Stay tuned.

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• Towards an F# .NET Reflector add-in

  - by CliveT

  When I had the opportunity to spent some time during Red Gate's recent "down tools" week on a project of my choice, the obvious project was an F# add-in for Reflector . To be honest, this was a bit of a misnomer as the amount of time in the designated week for coding was really less than three days, so it was always unlikely that very much progress would be made in such a small amount of time (and that certainly proved to be the case), but I did learn some things from the experiment. Like lots of problems, one useful technique is to take examples, get them to work, and then generalise to get something that works across the board. Unfortunately, I didn't have enough time to do the last stage. The obvious first step is to take a few function definitions, starting with the obvious hello world, moving on to a non-recursive function and finishing with the ubiquitous recursive Fibonacci function. let rec printMessage message  =     printfn  message let foo x  =    (x + 1) let rec fib x  =     if (x >= 2) then (fib (x - 1) + fib (x - 2)) else 1 The major problem in decompiling these simple functions is that Reflector has an in-memory object model that is designed to support object-oriented languages. In particular it has a return statement that allows function bodies to finish early. I used some of the in-built functionality to take the IL and produce an in-memory object model for the language, but then needed to write a transformer to push the return statements to the top of the tree to make it easy to render the code into a functional language. This tree transform works in some scenarios, but not in others where we simply regenerate code that looks more like CPS style. The next thing to get working was library level bindings of values where these values are calculated at runtime. let x = [1 ; 2 ; 3 ; 4] let y = List.map  (fun x -> foo x) x The way that this is translated into a set of classes for the underlying platform means that the code needs to follow references around, from the property exposing the calculated value to the class in which the code for generating the value is embedded. One of the strongest selling points of functional languages is the algebraic datatypes, which allow definitions via standard mathematical-style inductive definitions across the union cases. type Foo =     | Something of int     | Nothing type 'a Foo2 =     | Something2 of 'a     | Nothing2 Such a definition is compiled into a number of classes for the cases of the union, which all inherit from a class representing the type itself. It wasn't too hard to get such a de-compilation happening in the cases I tried. What did I learn from this? Firstly, that there are various bits of functionality inside Reflector that it would be useful for us to allow add-in writers to access. In particular, there are various implementations of the Visitor pattern which implement algorithms such as calculating the number of references for particular variables, and which perform various substitutions which could be more generally useful to add-in writers. I hope to do something about this at some point in the future. Secondly, when you transform a functional language into something that runs on top of an object-based platform, you lose some fidelity in the representation. The F# compiler leaves attributes in place so that tools can tell which classes represent classes from the source program and which are there for purposes of the implementation, allowing the decompiler to regenerate these constructs again. However, decompilation technology is a long way from being able to take unannotated IL and transform it into a program in a different language. For a simple function definition, like Fibonacci, I could write a simple static function and have it come out in F# as the same function, but it would be practically impossible to take a mass of class definitions and have a decompiler translate it automatically into an F# algebraic data type. What have we got out of this? Some data on the feasibility of implementing an F# decompiler inside Reflector, though it's hard at the moment to say how long this would take to do. The work we did is included the 6.5 EAP for Reflector that you can get from the EAP forum. All things considered though, it was a useful way to gain more familiarity with the process of writing an add-in and understand difficulties other add-in authors might experience. If you'd like to check out a video of Down Tools Week, click here.

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• error initializing multiple configuration files

  - by lurscher

  Hi, during initialization startup on tomcat, the configurations are: 1) a webapp/WEB-INF/web.xml that imports yummy-servlet.xml in contextConfigLocation (although i'm aware that is not required since the servlet-name is yummy it will try to load yummy-servlet.xml by default) 2) a webapp/WEB-INF/yummy-servlet.xml that imports a spring/applicationContext-hibernate.xml file 3) a webapp/WEB-INF/spring/applicationContext-hibernate.xml that imports a applicationContext-dataSource.xml file 4) a webapp/WEB-INF/spring/applicationContext-dataSource.xml i'm getting errors about Failed to import bean definitions from relative location, but the stack trace is not very explicit about exactly what is the problem, i've been looking at these since yesterday and i really don't see any problem on the files my web.xml: <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <display-name>hello-spring3-RC1</display-name> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/yummy-servlet.xml</param-value> </context-param> <!-- <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/spring/applicationContext-hibernate.xml</param-value> </context-param> --> <!-- Location of the Log4J config file, for initialization and refresh checks. Applied by Log4jConfigListener. --> <context-param> <param-name>log4jConfigLocation</param-name> <param-value>classpath:log4j.properties</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <servlet> <servlet-name>yummy</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>yummy</servlet-name> <url-pattern>*.html</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.html</welcome-file> </welcome-file-list> </web-app> my yummy-servlet.xml: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <import resource="spring/applicationContext-hibernate.xml"/> <context:component-scan base-package="com.mine.web.controllers"/> <bean id="jspViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean> </beans> my applicationContext-hibernate.xml: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"> <!-- import the dataSource definition --> <import resource="applicationContext-dataSource.xml"/> <!-- Configurer that replaces ${...} placeholders with values from a properties file --> <!-- (in this case, Hibernate-related settings for the sessionFactory definition below) --> <context:property-placeholder location="classpath:jdbc.properties"/> <context:property-placeholder location="classpath:hibernate.properties"/> <!-- Hibernate SessionFactory --> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean" p:dataSource-ref="dataSource" p:mappingResources="hello.hbm.xml"> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">${hibernate.dialect}</prop> <prop key="hibernate.show_sql">${hibernate.show_sql}</prop> <prop key="hibernate.generate_statistics">${hibernate.generate_statistics}</prop> </props> </property> <property name="eventListeners"> <map> <entry key="merge"> <bean class="org.springframework.orm.hibernate3.support.IdTransferringMergeEventListener"/> </entry> </map> </property> </bean> <bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate"> <property name="sessionFactory" ref="sessionFactory" /> </bean> <!-- Transaction manager for a single Hibernate SessionFactory (alternative to JTA) --> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager" p:sessionFactory-ref="sessionFactory"/> <!-- ========================= BUSINESS OBJECT DEFINITIONS ========================= --> <!-- Activates various annotations to be detected in bean classes: Spring's @Required and @Autowired, as well as JSR 250's @Resource. --> <context:annotation-config/> <!-- Instruct Spring to perform declarative transaction management automatically on annotated classes. --> <tx:annotation-driven transaction-manager="transactionManager"/> <bean id="EntityManager" class="com.mine.persistence.hibernate.HibernateHelloWorldDao"/> </beans> and my applicationContext-dataSource.xml: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd"> <!-- Configurer that replaces ${...} placeholders with values from a properties file --> <!-- (in this case, JDBC-related settings for the dataSource definition below) --> <context:property-placeholder location="classpath:jdbc.properties"/> <context:property-placeholder location="classpath:hibernate.properties"/> <!-- data source using apache common dbcp pool manager <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" p:driverClassName="${jdbc.driverClassName}" p:url="${jdbc.url}" p:username="${jdbc.username}" p:password="${jdbc.password}"/>--> <!-- c3p0 pool manager data source --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="${jdbc.driverClassName}"/> <property name="jdbcUrl" value="${jdbc.url}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <property name="initialPoolSize" value="${hibernate.c3p0.min_size}"/> <property name="minPoolSize" value="${hibernate.c3p0.min_size}"/> <property name="maxPoolSize" value="${jdbc.maxconn}"/> <property name="idleConnectionTestPeriod" value="150"/> <property name="acquireIncrement" value="1"/> <property name="maxStatements" value="0"/> <property name="numHelperThreads" value="5"/> </bean> </beans> and this is the stack trace: 2010-06-13 12:16:33,526 INFO [org.springframework.web.context.ContextLoader] - < Root WebApplicationContext: initialization started> 2010-06-13 12:16:33,707 INFO [org.springframework.web.context.support.XmlWebAppl icationContext] - <Refreshing Root WebApplicationContext: startup date [Sun Jun 13 12:16:33 GMT-05:00 2010]; root of context hierarchy> 2010-06-13 12:16:34,086 INFO [org.springframework.beans.factory.xml.XmlBeanDefin itionReader] - <Loading XML bean definitions from ServletContext resource [/WEB- INF/yummy-servlet.xml]> 2010-06-13 12:16:34,378 INFO [org.springframework.beans.factory.xml.XmlBeanDefin itionReader] - <Loading XML bean definitions from URL [jndi:/localhost/protoweb/ WEB-INF/spring/applicationContext-hibernate.xml]> 2010-06-13 12:16:34,473 INFO [org.springframework.beans.factory.xml.XmlBeanDefin itionReader] - <Loading XML bean definitions from URL [jndi:/localhost/protoweb/ WEB-INF/spring/applicationContext-dataSource.xml]> 2010-06-13 12:16:35,098 ERROR [org.springframework.web.context.ContextLoader] - <Context initialization failed> org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Failed to import bean definitions from relative location [spring/applicationContext-hibernate.xml] Offending resource: ServletContext resource [/WEB-INF/yummy-servlet.xml]; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Un expected exception parsing XML document from URL [jndi:/localhost/protoweb/WEB-INF/spring/applicationContext-hibernate.xml]; nested exception is java.lang.NoSuchMethodError: org.springframework.beans.MutablePropertyValues.add(Ljava/lang/Str ing;Ljava/lang/Object;)Lorg/springframework/beans/MutablePropertyValues; at org.springframework.beans.factory.parsing.FailFastProblemReporter.err or(FailFastProblemReporter.java:68) at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderC ontext.java:85) at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderC ontext.java:76) at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentRe ader.importBeanDefinitionResource(DefaultBeanDefinitionDocumentReader.java:197) at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentRe ader.parseDefaultElement(DefaultBeanDefinitionDocumentReader.java:146) at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentRe ader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:131) at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentRe ader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:91) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registe rBeanDefinitions(XmlBeanDefinitionReader.java:475) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadB eanDefinitions(XmlBeanDefinitionReader.java:372) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:316) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:284) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:125) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:93) at org.springframework.context.support.AbstractRefreshableApplicationCon text.refreshBeanFactory(AbstractRefreshableApplicationContext.java:127) at org.springframework.context.support.AbstractApplicationContext.obtain FreshBeanFactory(AbstractApplicationContext.java:429) at org.springframework.context.support.AbstractApplicationContext.refres h(AbstractApplicationContext.java:356) at org.springframework.web.context.ContextLoader.createWebApplicationCon text(ContextLoader.java:270) at org.springframework.web.context.ContextLoader.initWebApplicationConte xt(ContextLoader.java:197) at org.springframework.web.context.ContextLoaderListener.contextInitiali zed(ContextLoaderListener.java:47) at org.apache.catalina.core.StandardContext.listenerStart(StandardContex t.java:3972) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4 467) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase .java:791) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:77 1) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:546) at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:905) at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:740 ) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:500 ) at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1277) at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java :321) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(Lifecycl eSupport.java:119) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) at org.apache.catalina.core.StandardHost.start(StandardHost.java:785) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443 ) at org.apache.catalina.core.StandardService.start(StandardService.java:5 19) at org.apache.catalina.core.StandardServer.start(StandardServer.java:710 ) at org.apache.catalina.startup.Catalina.start(Catalina.java:581) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl. java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces sorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: Unexp ected exception parsing XML document from URL [jndi:/localhost/protoweb/WEB-INF/ spring/applicationContext-hibernate.xml]; nested exception is java.lang.NoSuchMe thodError: org.springframework.beans.MutablePropertyValues.add(Ljava/lang/String ;Ljava/lang/Object;)Lorg/springframework/beans/MutablePropertyValues; at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadB eanDefinitions(XmlBeanDefinitionReader.java:394) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:316) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:284) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178) at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentRe ader.importBeanDefinitionResource(DefaultBeanDefinitionDocumentReader.java:187) ... 42 more Caused by: java.lang.NoSuchMethodError: org.springframework.beans.MutablePropert yValues.add(Ljava/lang/String;Ljava/lang/Object;)Lorg/springframework/beans/Muta blePropertyValues; at org.springframework.transaction.config.AnnotationDrivenBeanDefinition Parser.registerTransactionManager(AnnotationDrivenBeanDefinitionParser.java:95) at org.springframework.transaction.config.AnnotationDrivenBeanDefinition Parser.access$0(AnnotationDrivenBeanDefinitionParser.java:94) at org.springframework.transaction.config.AnnotationDrivenBeanDefinition Parser$AopAutoProxyConfigurer.configureAutoProxyCreator(AnnotationDrivenBeanDefi nitionParser.java:121) at org.springframework.transaction.config.AnnotationDrivenBeanDefinition Parser.parse(AnnotationDrivenBeanDefinitionParser.java:79) at org.springframework.beans.factory.xml.NamespaceHandlerSupport.parse(N amespaceHandlerSupport.java:72) at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.pa rseCustomElement(BeanDefinitionParserDelegate.java:1327) at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.pa rseCustomElement(BeanDefinitionParserDelegate.java:1317) at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentRe ader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:134) at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentRe ader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:91) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registe rBeanDefinitions(XmlBeanDefinitionReader.java:475) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadB eanDefinitions(XmlBeanDefinitionReader.java:372) ... 47 more 06/13/2010 12:16:35 PM org.apache.catalina.core.StandardContext start SEVERE: Error listenerStart

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• Basic shadow mapping fails on NVIDIA card?

  - by James

  Recently I switched from an AMD Radeon HD 6870 card to an (MSI) NVIDIA GTX 670 for performance reasons. I found however that my implementation of shadow mapping in all my applications failed. In a very simple shadow POC project the problem appears to be that the scene being drawn never results in a draw to the depth map and as a result the entire depth map is just infinity, 1.0 (Reading directly from the depth component after draw (glReadPixels) shows every pixel is infinity (1.0), replacing the depth comparison in the shader with a comparison of the depth from the shadow map with 1.0 shadows the entire scene, and writing random values to the depth map and then not calling glClear(GL_DEPTH_BUFFER_BIT) results in a random noisy pattern on the scene elements - from which we can infer that the uploading of the depth texture and comparison within the shader are functioning perfectly.) Since the problem appears almost certainly to be in the depth render, this is the code for that: const int s_res = 1024; GLuint shadowMap_tex; GLuint shadowMap_prog; GLint sm_attr_coord3d; GLint sm_uniform_mvp; GLuint fbo_handle; GLuint renderBuffer; bool isMappingShad = false; //The scene consists of a plane with box above it GLfloat scene[] = { -10.0, 0.0, -10.0, 0.5, 0.0, 10.0, 0.0, -10.0, 1.0, 0.0, 10.0, 0.0, 10.0, 1.0, 0.5, -10.0, 0.0, -10.0, 0.5, 0.0, -10.0, 0.0, 10.0, 0.5, 0.5, 10.0, 0.0, 10.0, 1.0, 0.5, ... }; //Initialize the stuff used by the shadow map generator int initShadowMap() { //Initialize the shadowMap shader program if (create_program("shadow.v.glsl", "shadow.f.glsl", shadowMap_prog) != 1) return -1; const char* attribute_name = "coord3d"; sm_attr_coord3d = glGetAttribLocation(shadowMap_prog, attribute_name); if (sm_attr_coord3d == -1) { fprintf(stderr, "Could not bind attribute %s\n", attribute_name); return 0; } const char* uniform_name = "mvp"; sm_uniform_mvp = glGetUniformLocation(shadowMap_prog, uniform_name); if (sm_uniform_mvp == -1) { fprintf(stderr, "Could not bind uniform %s\n", uniform_name); return 0; } //Create a framebuffer glGenFramebuffers(1, &fbo_handle); glBindFramebuffer(GL_FRAMEBUFFER, fbo_handle); //Create render buffer glGenRenderbuffers(1, &renderBuffer); glBindRenderbuffer(GL_RENDERBUFFER, renderBuffer); //Setup the shadow texture glGenTextures(1, &shadowMap_tex); glBindTexture(GL_TEXTURE_2D, shadowMap_tex); glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, s_res, s_res, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); return 0; } //Delete stuff void dnitShadowMap() { //Delete everything glDeleteFramebuffers(1, &fbo_handle); glDeleteRenderbuffers(1, &renderBuffer); glDeleteTextures(1, &shadowMap_tex); glDeleteProgram(shadowMap_prog); } int loadSMap() { //Bind MVP stuff glm::mat4 view = glm::lookAt(glm::vec3(10.0, 10.0, 5.0), glm::vec3(0.0, 0.0, 0.0), glm::vec3(0.0, 1.0, 0.0)); glm::mat4 projection = glm::ortho<float>(-10,10,-8,8,-10,40); glm::mat4 mvp = projection * view; glm::mat4 biasMatrix( 0.5, 0.0, 0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.0, 0.5, 0.0, 0.5, 0.5, 0.5, 1.0 ); glm::mat4 lsMVP = biasMatrix * mvp; //Upload light source matrix to the main shader programs glUniformMatrix4fv(uniform_ls_mvp, 1, GL_FALSE, glm::value_ptr(lsMVP)); glUseProgram(shadowMap_prog); glUniformMatrix4fv(sm_uniform_mvp, 1, GL_FALSE, glm::value_ptr(mvp)); //Draw to the framebuffer (with depth buffer only draw) glBindFramebuffer(GL_FRAMEBUFFER, fbo_handle); glBindRenderbuffer(GL_RENDERBUFFER, renderBuffer); glBindTexture(GL_TEXTURE_2D, shadowMap_tex); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, shadowMap_tex, 0); glDrawBuffer(GL_NONE); glReadBuffer(GL_NONE); GLenum result = glCheckFramebufferStatus(GL_FRAMEBUFFER); if (GL_FRAMEBUFFER_COMPLETE != result) { printf("ERROR: Framebuffer is not complete.\n"); return -1; } //Draw shadow scene printf("Creating shadow buffers..\n"); int ticks = SDL_GetTicks(); glClear(GL_DEPTH_BUFFER_BIT); //Wipe the depth buffer glViewport(0, 0, s_res, s_res); isMappingShad = true; //DRAW glEnableVertexAttribArray(sm_attr_coord3d); glVertexAttribPointer(sm_attr_coord3d, 3, GL_FLOAT, GL_FALSE, 5*4, scene); glDrawArrays(GL_TRIANGLES, 0, 14*3); glDisableVertexAttribArray(sm_attr_coord3d); isMappingShad = false; glBindFramebuffer(GL_FRAMEBUFFER, 0); printf("Render Sbuf in %dms (GLerr: %d)\n", SDL_GetTicks() - ticks, glGetError()); return 0; } This is the full code for the POC shadow mapping project (C++) (Requires SDL 1.2, SDL-image 1.2, GLEW (1.5) and GLM development headers.) initShadowMap is called, followed by loadSMap, the scene is drawn from the camera POV and then dnitShadowMap is called. I followed this tutorial originally (Along with another more comprehensive tutorial which has disappeared as this guy re-configured his site but used to be here (404).) I've ensured that the scene is visible (as can be seen within the full project) to the light source (which uses an orthogonal projection matrix.) Shader utilities function fine in non-shadow-mapped projects. I should also note that at no point is the GL error state set. What am I doing wrong here and why did this not cause problems on my AMD card? (System: Ubuntu 12.04, Linux 3.2.0-49-generic, 64 bit, with the nvidia-experimental-310 driver package. All other games are functioning fine so it's most likely not a card/driver issue.)

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• IBM Keynote: (hardware,software)–>{IBM.java.patterns}

  - by Janice J. Heiss

  On Sunday evening, September 30, 2012, Jason McGee, IBM Distinguished Engineer and Chief Architect Cloud Computing, along with John Duimovich IBM Distinguished Engineer and Java CTO, gave an information- and idea-rich keynote that left Java developers with much to ponder.Their focus was on the challenges to make Java more efficient and productive given the hardware and software environments of 2012. “One idea that is very interesting is the idea of multi-tenancy,” said McGee, “and how we can move up the spectrum. In traditional systems, we ran applications on dedicated middleware, operating systems and hardware. A lot of customers still run that way. Now people introduce hardware virtualization and share the hardware. That is good but there is a lot more we can do. We can share middleware and the application itself.” McGee challenged developers to better enable the Java language to function in these higher density models. He spoke about the need to describe patterns that help us grasp the full environment that an application needs, whether it’s a web or full enterprise application. Developers need to understand the resources that an application interacts with in a way that is simple and straightforward. The task is to then automate that deployment so that the complexity of infrastructure can be by-passed and developers can live in a simpler world where the cloud can automatically configure the needed environment. McGee argued that the key, something IBM has been working on, is to use a simpler pattern that allows a cloud-based architecture to embrace the entire infrastructure required for an application and make it highly available, scalable and able to recover from failure. The cloud-based architecture would automate the complexity of setting up and managing the infrastructure. IBM has been trying to realize this vision for customers so they can describe their Java application environment simply and allow the cloud to automate the deployment and management of applications. “The point,” explained McGee, “is to package the executable used to describe applications, to drop it into a shared system and let that system provide some intelligence about how to deploy and manage those applications.”John Duimovich on Improvements in JavaMcGee then brought onstage IBM’s Distinguished Engineer and CTO for Java, John Duimovich, who showed the audience ways to deploy Java applications more efficiently.Duimovich explained that, “When you run lots of copies of Java in the cloud or any hypervisor virtualized system, there are a lot of duplications of code and jar files. IBM has a facility called ‘shared classes’ where we put shared code, read only artefacts in a cache that is sharable across hypervisors.” By putting JIT code in ahead of time, he explained that the application server will use 20% less memory and operate 30% faster.  He described another example of how the JVM allows for the maximum amount of sharing that manages the tenants and file sockets and memory use through throttling and control. Duimovich touched on the “thin is in” model and IBM’s Liberty Profile and lightweight runtime for the cloud, which allows for greater efficiency in interacting with the cloud.Duimovich discussed the confusion Java developers experience when, for example, the hypervisor tells them that that they have 8 and then 4 and then 16 cores. “Because hypervisors are virtualized, they can change based on resource needs across the hypervisor layer. You may have 10 instances of an operation system and you may need to reallocate memory, " explained Duimovich.  He showed how to resize LPARs, reallocate CPUs and migrate applications as needed. He explained how application servers can resize thread pools and better use resources based on information from the hypervisors.Java Challenges in Hardware and SoftwareMcGee ended the keynote with a summary of upcoming hardware and software challenges for the Java platform. He noted that one reason developers love Java is it allows them to ignore differences in hardware. He stated that the most important things happening in hardware were in network and storage – in developments such as the speed of SSD, the exploitation of high-speed, low-latency networking, and recent developments such as storage-class memory, and non-volatile main memory. “So we are challenged to maintain the benefits of Java and the abstraction it provides from hardware while still exploiting the new innovations in hardware,” said McGee.McGee discussed transactional messaging applications where developers send messages transactionally persist a message to storage, something traditionally done by backing messages on spinning disks, something mostly outdated. “Now,” he pointed out, “we would use SSD and store it in Flash and get 70,000 messages a second. If we stored it using a PCI express-based flash memory device, it is still Flash but put on a PCI express bus on a card closer to the CPU. This way I get 300,000 messages a second and 25% improvement in latency.” McGee’s central point was that hardware has a huge impact on the performance and scalability of applications. New technologies are enabling developers to build classes of Java applications previously unheard of. “We need to be able to balance these things in Java – we need to maintain the abstraction but also be able to exploit the evolution of hardware technology,” said McGee. According to McGee, IBM's current focus is on systems wherein hardware and software are shipped together in what are called Expert Integrated Systems – systems that are pre-optimized, and pre-integrated together. McGee closed IBM’s engaging and thought-provoking keynote by pointing out that the use of Java in complex applications is increasingly being augmented by a host of other languages with strong communities around them – JavaScript, JRuby, Scala, Python and so forth. Java developers now must understand the strengths and weaknesses of such newcomers as applications increasingly involve a complex interconnection of languages.

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• Using Sitecore RenderingContext Parameters as MVC controller action arguments

  - by Kyle Burns

  I have been working with the Technical Preview of Sitecore 6.6 on a project and have been for the most part happy with the way that Sitecore (which truly is an MVC implementation unto itself) has been expanded to support ASP.NET MVC. That said, getting up to speed with the combined platform has not been entirely without stumbles and today I want to share one area where Sitecore could have really made things shine from the "it just works" perspective. A couple days ago I was asked by a colleague about the usage of the "Parameters" field that is defined on Sitecore's Controller Rendering data template. Based on the standard way that Sitecore handles a field named Parameters, I was able to deduce that the field expected key/value pairs separated by the "&" character, but beyond that I wasn't sure and didn't see anything from a documentation perspective to guide me, so it was time to dig and find out where the data in the field was made available. My first thought was that it would be really nice if Sitecore handled the parameters in this field consistently with the way that ASP.NET MVC handles the various parameter collections on the HttpRequest object and automatically maps them to parameters of the action method executing. Being the hopeful sort, I configured a name/value pair on one of my renderings, added a parameter with matching name to the controller action and fired up the bugger to see... that the parameter was not populated. Having established that the field's value was not going to be presented to me the way that I had hoped it would, the next assumption that I would work on was that Sitecore would handle this field similar to how they handle other similar data and would plug it into some ambient object that I could reference from within the controller method. After a considerable amount of guessing, testing, and cracking code open with Redgate's Reflector (a must-have companion to Sitecore documentation), I found that the most direct way to access the parameter was through the ambient RenderingContext object using code similar to: string myArgument = string.Empty; var rc = Sitecore.Mvc.Presentation.RenderingContext.CurrentOrNull; if (rc != null) {     var parms = rc.Rendering.Parameters;     myArgument = parms["myArgument"]; } At this point, we know how this field is used out of the box from Sitecore and can provide information from Sitecore's Content Editor that will be available when the controller action is executing, but it feels a little dirty. In order to properly test the action method I would have to do a lot of setup work and possible use an isolation framework such as Pex and Moles to get at a value that my action method is dependent upon. Notice I said that my method is dependent upon the value but in order to meet that dependency I've accepted another dependency upon Sitecore's RenderingContext.  I'm a big believer in, when possible, ensuring that any piece of code explicitly advertises dependencies using the method signature, so I found myself still wanting this to work the same as if the parameters were in the request route, querystring, or form by being able to add a myArgument parameter to the action method and have this parameter populated by the framework. Lucky for us, the ASP.NET MVC framework is extremely flexible and provides some easy to grok and use extensibility points. ASP.NET MVC is able to provide information from the request as input parameters to controller actions because it uses objects which implement an interface called IValueProvider and have been registered to service the application. The most basic statement of responsibility for an IValueProvider implementation is "I know about some data which is indexed by key. If you hand me the key for a piece of data that I know about I give you that data". When preparing to invoke a controller action, the framework queries registered IValueProvider implementations with the name of each method argument to see if the ValueProvider can supply a value for the parameter. (the rest of this post will assume you're working along and make a lot more sense if you do) Let's pull Sitecore out of the equation for a second to simplify things and create an extremely simple IValueProvider implementation. For this example, I first create a new ASP.NET MVC3 project in Visual Studio, selecting "Internet Application" and otherwise taking defaults (I'm assuming that anyone reading this far in the post either already knows how to do this or will need to take a quick run through one of the many available basic MVC tutorials such as the MVC Music Store). Once the new project is created, go to the Index action of HomeController.  This action sets a Message property on the ViewBag to "Welcome to ASP.NET MVC!" and invokes the View, which has been coded to display the Message. For our example, we will remove the hard coded message from this controller (although we'll leave it just as hard coded somewhere else - this is sample code). For the first step in our exercise, add a string parameter to the Index action method called welcomeMessage and use the value of this argument to set the ViewBag.Message property. The updated Index action should look like: public ActionResult Index(string welcomeMessage) {     ViewBag.Message = welcomeMessage;     return View(); } This represents the entirety of the change that you will make to either the controller or view.  If you run the application now, the home page will display and no message will be presented to the user because no value was supplied to the Action method. Let's now write a ValueProvider to ensure this parameter gets populated. We'll start by creating a new class called StaticValueProvider. When the class is created, we'll update the using statements to ensure that they include the following: using System.Collections.Specialized; using System.Globalization; using System.Web.Mvc; With the appropriate using statements in place, we'll update the StaticValueProvider class to implement the IValueProvider interface. The System.Web.Mvc library already contains a pretty flexible dictionary-like implementation called NameValueCollectionValueProvider, so we'll just wrap that and let it do most of the real work for us. The completed class looks like: public class StaticValueProvider : IValueProvider {     private NameValueCollectionValueProvider _wrappedProvider;     public StaticValueProvider(ControllerContext controllerContext)     {         var parameters = new NameValueCollection();         parameters.Add("welcomeMessage", "Hello from the value provider!");         _wrappedProvider = new NameValueCollectionValueProvider(parameters, CultureInfo.InvariantCulture);     }     public bool ContainsPrefix(string prefix)     {         return _wrappedProvider.ContainsPrefix(prefix);     }     public ValueProviderResult GetValue(string key)     {         return _wrappedProvider.GetValue(key);     } } Notice that the only entry in the collection matches the name of the argument to our HomeController's Index action.  This is the important "secret sauce" that will make things work. We've got our new value provider now, but that's not quite enough to be finished. Mvc obtains IValueProvider instances using factories that are registered when the application starts up. These factories extend the abstract ValueProviderFactory class by initializing and returning the appropriate implementation of IValueProvider from the GetValueProvider method. While I wouldn't do so in production code, for the sake of this example, I'm going to add the following class definition within the StaticValueProvider.cs source file: public class StaticValueProviderFactory : ValueProviderFactory {     public override IValueProvider GetValueProvider(ControllerContext controllerContext)     {         return new StaticValueProvider(controllerContext);     } } Now that we have a factory, we can register it by adding the following line to the end of the Application_Start method in Global.asax.cs: ValueProviderFactories.Factories.Add(new StaticValueProviderFactory()); If you've done everything right to this point, you should be able to run the application and be presented with the home page reading "Hello from the value provider!". Now that you have the basics of the IValueProvider down, you have everything you need to enhance your Sitecore MVC implementation by adding an IValueProvider that exposes values from the ambient RenderingContext's Parameters property. I'll provide the code for the IValueProvider implementation (which should look VERY familiar) and you can use the work we've already done as a reference to create and register the factory: public class RenderingContextValueProvider : IValueProvider {     private NameValueCollectionValueProvider _wrappedProvider = null;     public RenderingContextValueProvider(ControllerContext controllerContext)     {         var collection = new NameValueCollection();         var rc = RenderingContext.CurrentOrNull;         if (rc != null && rc.Rendering != null)         {             foreach(var parameter in rc.Rendering.Parameters)             {                 collection.Add(parameter.Key, parameter.Value);             }         }         _wrappedProvider = new NameValueCollectionValueProvider(collection, CultureInfo.InvariantCulture);         }     public bool ContainsPrefix(string prefix)     {         return _wrappedProvider.ContainsPrefix(prefix);     }     public ValueProviderResult GetValue(string key)     {         return _wrappedProvider.GetValue(key);     } } In this post I've discussed the MVC IValueProvider used to map data to controller action method arguments and how this can be integrated into your Sitecore 6.6 MVC solution.

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• Creating Property Set Expression Trees In A Developer Friendly Way

  - by Paulo Morgado

  In a previous post I showed how to create expression trees to set properties on an object. The way I did it was not very developer friendly. It involved explicitly creating the necessary expressions because the compiler won’t generate expression trees with property or field set expressions. Recently someone contacted me the help develop some kind of command pattern framework that used developer friendly lambdas to generate property set expression trees. Simply putting, given this entity class: public class Person { public string Name { get; set; } } The person in question wanted to write code like this: var et = Set((Person p) => p.Name = "me"); Where et is the expression tree that represents the property assignment. So, if we can’t do this, let’s try the next best thing that is splitting retrieving the property information from the retrieving the value to assign o the property: var et = Set((Person p) => p.Name, () => "me"); And this is something that the compiler can handle. The implementation of Set receives an expression to retrieve the property information from and another expression the retrieve the value to assign to the property: public static Expression<Action<TEntity>> Set<TEntity, TValue>( Expression<Func<TEntity, TValue>> propertyGetExpression, Expression<Func<TValue>> valueExpression) The implementation of this method gets the property information form the body of the property get expression (propertyGetExpression) and the value expression (valueExpression) to build an assign expression and builds a lambda expression using the same parameter of the property get expression as its parameter: public static Expression<Action<TEntity>> Set<TEntity, TValue>( Expression<Func<TEntity, TValue>> propertyGetExpression, Expression<Func<TValue>> valueExpression) { var entityParameterExpression = (ParameterExpression)(((MemberExpression)(propertyGetExpression.Body)).Expression); return Expression.Lambda<Action<TEntity>>( Expression.Assign(propertyGetExpression.Body, valueExpression.Body), entityParameterExpression); } And now we can use the expression to translate to another context or just compile and use it: var et = Set((Person p) => p.Name, () => name); Console.WriteLine(person.Name); // Prints: p => (p.Name = “me”) var d = et.Compile(); d(person); Console.WriteLine(person.Name); // Prints: me It can even support closures: var et = Set((Person p) => p.Name, () => name); Console.WriteLine(person.Name); // Prints: p => (p.Name = value(<>c__DisplayClass0).name) var d = et.Compile(); name = "me"; d(person); Console.WriteLine(person.Name); // Prints: me name = "you"; d(person); Console.WriteLine(person.Name); // Prints: you Not so useful in the intended scenario (but still possible) is building an expression tree that receives the value to assign to the property as a parameter: public static Expression<Action<TEntity, TValue>> Set<TEntity, TValue>(Expression<Func<TEntity, TValue>> propertyGetExpression) { var entityParameterExpression = (ParameterExpression)(((MemberExpression)(propertyGetExpression.Body)).Expression); var valueParameterExpression = Expression.Parameter(typeof(TValue)); return Expression.Lambda<Action<TEntity, TValue>>( Expression.Assign(propertyGetExpression.Body, valueParameterExpression), entityParameterExpression, valueParameterExpression); } This new expression can be used like this: var et = Set((Person p) => p.Name); Console.WriteLine(person.Name); // Prints: (p, Param_0) => (p.Name = Param_0) var d = et.Compile(); d(person, "me"); Console.WriteLine(person.Name); // Prints: me d(person, "you"); Console.WriteLine(person.Name); // Prints: you The only caveat is that we need to be able to write code to read the property in order to write to it.

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• PostSharp, Obfuscation, and IL

  - by Simon Cooper

  Aspect-oriented programming (AOP) is a relatively new programming paradigm. Originating at Xerox PARC in 1994, the paradigm was first made available for general-purpose development as an extension to Java in 2001. From there, it has quickly been adapted for use in all the common languages used today. In the .NET world, one of the primary AOP toolkits is PostSharp. Attributes and AOP Normally, attributes in .NET are entirely a metadata construct. Apart from a few special attributes in the .NET framework, they have no effect whatsoever on how a class or method executes within the CLR. Only by using reflection at runtime can you access any attributes declared on a type or type member. PostSharp changes this. By declaring a custom attribute that derives from PostSharp.Aspects.Aspect, applying it to types and type members, and running the resulting assembly through the PostSharp postprocessor, you can essentially declare 'clever' attributes that change the behaviour of whatever the aspect has been applied to at runtime. A simple example of this is logging. By declaring a TraceAttribute that derives from OnMethodBoundaryAspect, you can automatically log when a method has been executed: public class TraceAttribute : PostSharp.Aspects.OnMethodBoundaryAspect { public override void OnEntry(MethodExecutionArgs args) { MethodBase method = args.Method; System.Diagnostics.Trace.WriteLine( String.Format( "Entering {0}.{1}.", method.DeclaringType.FullName, method.Name)); } public override void OnExit(MethodExecutionArgs args) { MethodBase method = args.Method; System.Diagnostics.Trace.WriteLine( String.Format( "Leaving {0}.{1}.", method.DeclaringType.FullName, method.Name)); } } [Trace] public void MethodToLog() { ... } Now, whenever MethodToLog is executed, the aspect will automatically log entry and exit, without having to add the logging code to MethodToLog itself. PostSharp Performance Now this does introduce a performance overhead - as you can see, the aspect allows access to the MethodBase of the method the aspect has been applied to. If you were limited to C#, you would be forced to retrieve each MethodBase instance using Type.GetMethod(), matching on the method name and signature. This is slow. Fortunately, PostSharp is not limited to C#. It can use any instruction available in IL. And in IL, you can do some very neat things. Ldtoken C# allows you to get the Type object corresponding to a specific type name using the typeof operator: Type t = typeof(Random); The C# compiler compiles this operator to the following IL: ldtoken [mscorlib]System.Random call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle( valuetype [mscorlib]System.RuntimeTypeHandle) The ldtoken instruction obtains a special handle to a type called a RuntimeTypeHandle, and from that, the Type object can be obtained using GetTypeFromHandle. These are both relatively fast operations - no string lookup is required, only direct assembly and CLR constructs are used. However, a little-known feature is that ldtoken is not just limited to types; it can also get information on methods and fields, encapsulated in a RuntimeMethodHandle or RuntimeFieldHandle: // get a MethodBase for String.EndsWith(string) ldtoken method instance bool [mscorlib]System.String::EndsWith(string) call class [mscorlib]System.Reflection.MethodBase [mscorlib]System.Reflection.MethodBase::GetMethodFromHandle( valuetype [mscorlib]System.RuntimeMethodHandle) // get a FieldInfo for the String.Empty field ldtoken field string [mscorlib]System.String::Empty call class [mscorlib]System.Reflection.FieldInfo [mscorlib]System.Reflection.FieldInfo::GetFieldFromHandle( valuetype [mscorlib]System.RuntimeFieldHandle) These usages of ldtoken aren't usable from C# or VB, and aren't likely to be added anytime soon (Eric Lippert's done a blog post on the possibility of adding infoof, methodof or fieldof operators to C#). However, PostSharp deals directly with IL, and so can use ldtoken to get MethodBase objects quickly and cheaply, without having to resort to string lookups. The kicker However, there are problems. Because ldtoken for methods or fields isn't accessible from C# or VB, it hasn't been as well-tested as ldtoken for types. This has resulted in various obscure bugs in most versions of the CLR when dealing with ldtoken and methods, and specifically, generic methods and methods of generic types. This means that PostSharp was behaving incorrectly, or just plain crashing, when aspects were applied to methods that were generic in some way. So, PostSharp has to work around this. Without using the metadata tokens directly, the only way to get the MethodBase of generic methods is to use reflection: Type.GetMethod(), passing in the method name as a string along with information on the signature. Now, this works fine. It's slower than using ldtoken directly, but it works, and this only has to be done for generic methods. Unfortunately, this poses problems when the assembly is obfuscated. PostSharp and Obfuscation When using ldtoken, obfuscators don't affect how PostSharp operates. Because the ldtoken instruction directly references the type, method or field within the assembly, it is unaffected if the name of the object is changed by an obfuscator. However, the indirect loading used for generic methods was breaking, because that uses the name of the method when the assembly is put through the PostSharp postprocessor to lookup the MethodBase at runtime. If the name then changes, PostSharp can't find it anymore, and the assembly breaks. So, PostSharp needs to know about any changes an obfuscator does to an assembly. The way PostSharp does this is by adding another layer of indirection. When PostSharp obfuscation support is enabled, it includes an extra 'name table' resource in the assembly, consisting of a series of method & type names. When PostSharp needs to lookup a method using reflection, instead of encoding the method name directly, it looks up the method name at a fixed offset inside that name table: MethodBase genericMethod = typeof(ContainingClass).GetMethod(GetNameAtIndex(22)); PostSharp.NameTable resource: ... 20: get_Prop1 21: set_Prop1 22: DoFoo 23: GetWibble When the assembly is later processed by an obfuscator, the obfuscator can replace all the method and type names within the name table with their new name. That way, the reflection lookups performed by PostSharp will now use the new names, and everything will work as expected: MethodBase genericMethod = typeof(#kGy).GetMethod(GetNameAtIndex(22)); PostSharp.NameTable resource: ... 20: #kkA 21: #zAb 22: #EF5a 23: #2tg As you can see, this requires direct support by an obfuscator in order to perform these rewrites. Dotfuscator supports it, and now, starting with SmartAssembly 6.6.4, SmartAssembly does too. So, a relatively simple solution to a tricky problem, with some CLR bugs thrown in for good measure. You don't see those every day!

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• ASP.NET WebAPI Security 4: Examples for various Authentication Scenarios

  - by Your DisplayName here!

  The Thinktecture.IdentityModel.Http repository includes a number of samples for the various authentication scenarios. All the clients follow a basic pattern: Acquire client credential (a single token, multiple tokens, username/password). Call Service. The service simply enumerates the claims it finds on the request and returns them to the client. I won’t show that part of the code, but rather focus on the step 1 and 2. Basic Authentication This is the most basic (pun inteneded) scenario. My library contains a class that can create the Basic Authentication header value. Simply set username and password and you are good to go. var client = new HttpClient { BaseAddress = _baseAddress }; client.DefaultRequestHeaders.Authorization = new BasicAuthenticationHeaderValue("alice", "alice"); var response = client.GetAsync("identity").Result; response.EnsureSuccessStatusCode();   SAML Authentication To integrate a Web API with an existing enterprise identity provider like ADFS, you can use SAML tokens. This is certainly not the most efficient way of calling a “lightweight service” ;) But very useful if that’s what it takes to get the job done. private static string GetIdentityToken() {     var factory = new WSTrustChannelFactory(         new WindowsWSTrustBinding(SecurityMode.Transport),         _idpEndpoint);     factory.TrustVersion = TrustVersion.WSTrust13;     var rst = new RequestSecurityToken     {         RequestType = RequestTypes.Issue,         KeyType = KeyTypes.Bearer,         AppliesTo = new EndpointAddress(Constants.Realm)     };     var token = factory.CreateChannel().Issue(rst) as GenericXmlSecurityToken;     return token.TokenXml.OuterXml; } private static Identity CallService(string saml) {     var client = new HttpClient { BaseAddress = _baseAddress };     client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("SAML", saml);     var response = client.GetAsync("identity").Result;     response.EnsureSuccessStatusCode();     return response.Content.ReadAsAsync<Identity>().Result; }   SAML to SWT conversion using the Azure Access Control Service Another possible options for integrating SAML based identity providers is to use an intermediary service that allows converting the SAML token to the more compact SWT (Simple Web Token) format. This way you only need to roundtrip the SAML once and can use the SWT afterwards. The code for the conversion uses the ACS OAuth2 endpoint. The OAuth2Client class is part of my library. private static string GetServiceTokenOAuth2(string samlToken) {     var client = new OAuth2Client(_acsOAuth2Endpoint);     return client.RequestAccessTokenAssertion(         samlToken,         SecurityTokenTypes.Saml2TokenProfile11,         Constants.Realm).AccessToken; }   SWT Authentication When you have an identity provider that directly supports a (simple) web token, you can acquire the token directly without the conversion step. Thinktecture.IdentityServer e.g. supports the OAuth2 resource owner credential profile to issue SWT tokens. private static string GetIdentityToken() {     var client = new OAuth2Client(_oauth2Address);     var response = client.RequestAccessTokenUserName("bob", "abc!123", Constants.Realm);     return response.AccessToken; } private static Identity CallService(string swt) {     var client = new HttpClient { BaseAddress = _baseAddress };     client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", swt);     var response = client.GetAsync("identity").Result;     response.EnsureSuccessStatusCode();     return response.Content.ReadAsAsync<Identity>().Result; }   So you can see that it’s pretty straightforward to implement various authentication scenarios using WebAPI and my authentication library. Stay tuned for more client samples!

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• Blog Buzz - Devoxx 2011

  - by Janice J. Heiss

  Some day I will make it to Devoxx – for now, I’m content to vicariously follow the blogs of attendees and pick up on what’s happening.  I’ve been doing more blog "fishing," looking for the best commentary on 2011 Devoxx. There’s plenty of food for thought – and the ideas are not half-baked.The bloggers are out in full, offering useful summaries and commentary on Devoxx goings-on.Constantin Partac, a Java developer and a member of Transylvania JUG, a community from Cluj-Napoca/Romania, offers an excellent summary of the Devoxx keynotes. Here’s a sample:“Oracle Opening Keynote and JDK 7, 8, and 9 Presentation•    Oracle is committed to Java and wants to provide support for it on any device.•    JSE 7 for Mac will be released next week.•    Oracle would like Java developers to be involved in JCP, to adopt a JSR and to attend local JUG meetings.•    JEE 7 will be released next year.•    JEE 7 is focused on cloud integration, some of the features are already implemented in glassfish 4 development branch.•    JSE 8 will be release in summer of 2013 due to “enterprise community request” as they can not keep the pace with an 18    month release cycle.•    The main features included in JSE8 are lambda support, project Jigsaw, new Date/Time API, project Coin++ and adding   support for sensors. JSE 9 probably will focus on some of these features:1.    self tuning JVM2.    improved native language integration3.    processing enhancement for big data4.    reification (adding runtime class type info for generic types)5.    unification of primitive and corresponding object classes6.    meta-object protocol in order to use type and methods define in other JVM languages7.    multi-tenancy8.    JVM resource management” Thanks Constantin! Ivan St. Ivanov, of SAP Labs Bulgaria, also commented on the keynotes with a different focus.  He summarizes Henrik Stahl’s look ahead to Java SE 8 and JavaFX 3.0; Cameron Purdy on Java EE and the cloud; celebrated Java Champion Josh Bloch on what’s good and bad about Java; Mark Reinhold’s quick look ahead to Java SE 9; and Brian Goetz on lambdas and default methods in Java SE 8. Here’s St. Ivanov’s account of Josh Bloch’s comments on the pluses of Java:“He started with the virtues of the platform. To name a few:    Tightly specified language primitives and evaluation order – int is always 32 bits and operations are executed always from left  to right, without compilers messing around    Dynamic linking – when you change a class, you need to recompile and rebuild just the jar that has it and not the whole application    Syntax  similarity with C/C++ – most existing developers at that time felt like at home    Object orientations – it was cool at that time as well as functional programming is today    It was statically typed language – helps in faster runtime, better IDE support, etc.    No operator overloading – well, I’m not sure why it is good. Scala has it for example and that’s why it is far better for defining DSLs. But I will not argue with Josh.”It’s worth checking out St. Ivanov’s summary of Bloch’s views on what’s not so great about Java as well. What's Coming in JAX-RS 2.0Marek Potociar, Principal Software Engineer at Oracle and currently specification lead of Java EE RESTful web services API (JAX-RS), blogged on his talk about what's coming in JAX-RS 2.0, scheduled for final release in mid-2012.  Here’s a taste:“Perhaps the most wanted addition to the JAX-RS is the Client API, that would complete the JAX-RS story, that is currently server-side only. In JAX-RS 2.0 we are adding a completely interface-based and fluent client API that blends nicely in with the existing fluent response builder pattern on the server-side. When we started with the client API, the first proposal contained around 30 classes. Thanks to the feedback from our Expert Group we managed to reduce the number of API classes to 14 (2 of them being exceptions)! The resulting is compact while at the same time we still managed to create an API that reflects the method invocation context flow (e.g. once you decide on the target URI and start setting headers on the request, your IDE will not try to offer you a URI setter in the code completion). This is a subtle but very important usability aspect of an API…” Obviously, Devoxx is a great Java conference, one that is hitting this year at a time when much is brewing in the platform and beginning to be anticipated.

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• Integration Patterns with Azure Service Bus Relay, Part 2: Anonymous full-trust .NET consumer

  - by Elton Stoneman

  This is the second in the IPASBR series, see also: Integration Patterns with Azure Service Bus Relay, Part 1: Exposing the on-premise service Part 2 is nice and easy. From Part 1 we exposed our service over the Azure Service Bus Relay using the netTcpRelayBinding and verified we could set up our network to listen for relayed messages. Assuming we want to consume that service in .NET from an environment which is fairly unrestricted for us, but quite restricted for attackers, we can use netTcpRelay and shared secret authentication. Pattern applicability This is a good fit for scenarios where: the consumer can run .NET in full trust the environment does not restrict use of external DLLs the runtime environment is secure enough to keep shared secrets the service does not need to know who is consuming it the service does not need to know who the end-user is So for example, the consumer is an ASP.NET website sitting in a cloud VM or Azure worker role, where we can keep the shared secret in web.config and we don't need to flow any identity through to the on-premise service. The service doesn't care who the consumer or end-user is - say it's a reference data service that provides a list of vehicle manufacturers. Provided you can authenticate with ACS and have access to Service Bus endpoint, you can use the service and it doesn't care who you are. In this post, we’ll consume the service from Part 1 in ASP.NET using netTcpRelay. The code for Part 2 (+ Part 1) is on GitHub here: IPASBR Part 2 Authenticating and authorizing with ACS In this scenario the consumer is a server in a controlled environment, so we can use a shared secret to authenticate with ACS, assuming that there is governance around the environment and the codebase which will prevent the identity being compromised. From the provider's side, we will create a dedicated service identity for this consumer, so we can lock down their permissions. The provider controls the identity, so the consumer's rights can be revoked. We'll add a new service identity for the namespace in ACS , just as we did for the serviceProvider identity in Part 1. I've named the identity fullTrustConsumer. We then need to add a rule to map the incoming identity claim to an outgoing authorization claim that allows the identity to send messages to Service Bus (see Part 1 for a walkthrough creating Service Idenitities): Issuer: Access Control Service Input claim type: http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier Input claim value: fullTrustConsumer Output claim type: net.windows.servicebus.action Output claim value: Send This sets up a service identity which can send messages into Service Bus, but cannot register itself as a listener, or manage the namespace. Adding a Service Reference The Part 2 sample client code is ready to go, but if you want to replicate the steps, you’re going to add a WSDL reference, add a reference to Microsoft.ServiceBus and sort out the ServiceModel config. In Part 1 we exposed metadata for our service, so we can browse to the WSDL locally at: http://localhost/Sixeyed.Ipasbr.Services/FormatService.svc?wsdl If you add a Service Reference to that in a new project you'll get a confused config section with a customBinding, and a set of unrecognized policy assertions in the namespace http://schemas.microsoft.com/netservices/2009/05/servicebus/connect. If you NuGet the ASB package (“windowsazure.servicebus”) first and add the service reference - you'll get the same messy config. Either way, the WSDL should have downloaded and you should have the proxy code generated. You can delete the customBinding entries and copy your config from the service's web.config (this is already done in the sample project in Sixeyed.Ipasbr.NetTcpClient), specifying details for the client:     <client>       <endpoint address="sb://sixeyed-ipasbr.servicebus.windows.net/net"                 behaviorConfiguration="SharedSecret"                 binding="netTcpRelayBinding"                 contract="FormatService.IFormatService" />     </client>     <behaviors>       <endpointBehaviors>         <behavior name="SharedSecret">           <transportClientEndpointBehavior credentialType="SharedSecret">             <clientCredentials>               <sharedSecret issuerName="fullTrustConsumer"                             issuerSecret="E3feJSMuyGGXksJi2g2bRY5/Bpd2ll5Eb+1FgQrXIqo="/>             </clientCredentials>           </transportClientEndpointBehavior>         </behavior>       </endpointBehaviors>     </behaviors>   The proxy is straight WCF territory, and the same client can run against Azure Service Bus through any relay binding, or directly to the local network service using any WCF binding - the contract is exactly the same. The code is simple, standard WCF stuff: using (var client = new FormatService.FormatServiceClient()) { outputString = client.ReverseString(inputString); } Running the sample First, update Solution Items\AzureConnectionDetails.xml with your service bus namespace, and your service identity credentials for the netTcpClient and the provider:   <!-- ACS credentials for the full trust consumer (Part2): -->   <netTcpClient identityName="fullTrustConsumer"                 symmetricKey="E3feJSMuyGGXksJi2g2bRY5/Bpd2ll5Eb+1FgQrXIqo="/> Then rebuild the solution and verify the unit tests work. If they’re green, your service is listening through Azure. Check out the client by navigating to http://localhost:53835/Sixeyed.Ipasbr.NetTcpClient. Enter a string and hit Go! - your string will be reversed by your on-premise service, routed through Azure: Using shared secret client credentials in this way means ACS is the identity provider for your service, and the claim which allows Send access to Service Bus is consumed by Service Bus. None of the authentication details make it through to your service, so your service is not aware who the consumer is (MSDN calls this "anonymous authentication").

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• HTG Explains: Should You Build Your Own PC?

  - by Chris Hoffman

  There was a time when every geek seemed to build their own PC. While the masses bought eMachines and Compaqs, geeks built their own more powerful and reliable desktop machines for cheaper. But does this still make sense? Building your own PC still offers as much flexibility in component choice as it ever did, but prebuilt computers are available at extremely competitive prices. Building your own PC will no longer save you money in most cases. The Rise of Laptops It’s impossible to look at the decline of geeks building their own PCs without considering the rise of laptops. There was a time when everyone seemed to use desktops — laptops were more expensive and significantly slower in day-to-day tasks. With the diminishing importance of computing power — nearly every modern computer has more than enough power to surf the web and use typical programs like Microsoft Office without any trouble — and the rise of laptop availability at nearly every price point, most people are buying laptops instead of desktops. And, if you’re buying a laptop, you can’t really build your own. You can’t just buy a laptop case and start plugging components into it — even if you could, you would end up with an extremely bulky device. Ultimately, to consider building your own desktop PC, you have to actually want a desktop PC. Most people are better served by laptops. Benefits to PC Building The two main reasons to build your own PC have been component choice and saving money. Building your own PC allows you to choose all the specific components you want rather than have them chosen for you. You get to choose everything, including the PC’s case and cooling system. Want a huge case with room for a fancy water-cooling system? You probably want to build your own PC. In the past, this often allowed you to save money — you could get better deals by buying the components yourself and combining them, avoiding the PC manufacturer markup. You’d often even end up with better components — you could pick up a more powerful CPU that was easier to overclock and choose more reliable components so you wouldn’t have to put up with an unstable eMachine that crashed every day. PCs you build yourself are also likely more upgradable — a prebuilt PC may have a sealed case and be constructed in such a way to discourage you from tampering with the insides, while swapping components in and out is generally easier with a computer you’ve built on your own. If you want to upgrade your CPU or replace your graphics card, it’s a definite benefit. Downsides to Building Your Own PC It’s important to remember there are downsides to building your own PC, too. For one thing, it’s just more work — sure, if you know what you’re doing, building your own PC isn’t that hard. Even for a geek, researching the best components, price-matching, waiting for them all to arrive, and building the PC just takes longer. Warranty is a more pernicious problem. If you buy a prebuilt PC and it starts malfunctioning, you can contact the computer’s manufacturer and have them deal with it. You don’t need to worry about what’s wrong. If you build your own PC and it starts malfunctioning, you have to diagnose the problem yourself. What’s malfunctioning, the motherboard, CPU, RAM, graphics card, or power supply? Each component has a separate warranty through its manufacturer, so you’ll have to determine which component is malfunctioning before you can send it off for replacement. Should You Still Build Your Own PC? Let’s say you do want a desktop and are willing to consider building your own PC. First, bear in mind that PC manufacturers are buying in bulk and getting a better deal on each component. They also have to pay much less for a Windows license than the $120 or so it would cost you to to buy your own Windows license. This is all going to wipe out the cost savings you’ll see — with everything all told, you’ll probably spend more money building your own average desktop PC than you would picking one up from Amazon or the local electronics store. If you’re an average PC user that uses your desktop for the typical things, there’s no money to be saved from building your own PC. But maybe you’re looking for something higher end. Perhaps you want a high-end gaming PC with the fastest graphics card and CPU available. Perhaps you want to pick out each individual component and choose the exact components for your gaming rig. In this case, building your own PC may be a good option. As you start to look at more expensive, high-end PCs, you may start to see a price gap — but you may not. Let’s say you wanted to blow thousands of dollars on a gaming PC. If you’re looking at spending this kind of money, it would be worth comparing the cost of individual components versus a prebuilt gaming system. Still, the actual prices may surprise you. For example, if you wanted to upgrade Dell’s $2293 Alienware Aurora to include a second NVIDIA GeForce GTX 780 graphics card, you’d pay an additional $600 on Alienware’s website. The same graphics card costs $650 on Amazon or Newegg, so you’d be spending more money building the system yourself. Why? Dell’s Alienware gets bulk discounts you can’t get — and this is Alienware, which was once regarded as selling ridiculously overpriced gaming PCs to people who wouldn’t build their own. Building your own PC still allows you to get the most freedom when choosing and combining components, but this is only valuable to a small niche of gamers and professional users — most people, even average gamers, would be fine going with a prebuilt system. If you’re an average person or even an average gamer, you’ll likely find that it’s cheaper to purchase a prebuilt PC rather than assemble your own. Even at the very high end, components may be more expensive separately than they are in a prebuilt PC. Enthusiasts who want to choose all the individual components for their dream gaming PC and want maximum flexibility may want to build their own PCs. Even then, building your own PC these days is more about flexibility and component choice than it is about saving money. In summary, you probably shouldn’t build your own PC. If you’re an enthusiast, you may want to — but only a small minority of people would actually benefit from building their own systems. Feel free to compare prices, but you may be surprised which is cheaper. Image Credit: Richard Jones on Flickr, elPadawan on Flickr, Richard Jones on Flickr     

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• Implementing synchronous MediaTypeFormatters in ASP.NET Web API

  - by cibrax

  One of main characteristics of MediaTypeFormatter’s in ASP.NET Web API is that they leverage the Task Parallel Library (TPL) for reading or writing an model into an stream. When you derive your class from the base class MediaTypeFormatter, you have to either implement the WriteToStreamAsync or ReadFromStreamAsync methods for writing or reading a model from a stream respectively. These two methods return a Task, which internally does all the serialization work, as it is illustrated bellow. public abstract class MediaTypeFormatter { public virtual Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext); public virtual Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger); }   .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } However, most of the times, serialization is a safe operation that can be done synchronously. In fact, many of the serializer classes you will find in the .NET framework only provide sync methods. So the question is, how you can transform that synchronous work into a Task ?. Creating a new task using the method Task.Factory.StartNew for doing all the serialization work would be probably the typical answer. That would work, as a new task is going to be scheduled. However, that might involve some unnecessary context switches, which are out of our control and might be affect performance on server code specially.   If you take a look at the source code of the MediaTypeFormatters shipped as part of the framework, you will notice that they actually using another pattern, which uses a TaskCompletionSource class. public Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext) {   var tsc = new TaskCompletionSource<AsyncVoid>(); tsc.SetResult(default(AsyncVoid));   //Do all the serialization work here synchronously   return tsc.Task; }   /// <summary> /// Used as the T in a "conversion" of a Task into a Task{T} /// </summary> private struct AsyncVoid { } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } They are basically doing all the serialization work synchronously and using a TaskCompletionSource for returning a task already done. To conclude this post, this is another approach you might want to consider when using serializers that are not compatible with an async model. Update: Henrik Nielsen from the ASP.NET team pointed out the existence of a built-in media type formatter for writing sync formatters. BufferedMediaTypeFormatter http://t.co/FxOfeI5x

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• RDA Health Checks for SOA

  - by ShawnBailey

  What is a health check in RDA? A health check evaluates something in your environment to determine whether a change needs to be considered in order to avoid a problem or optimize fuctionality. Examples of what this 'something' might be are: Configuration Parameters JVM Options Runtime Statistics What have we done for SOA? In the latest release of RDA, 4.30, we have added a Rule Set for SOA called 'Oracle SOA 11g (11.1.1) Post Installation (Generic)'. This Rule Set contains 14 SOA related health checks. These checks were all derived from common issues / solutions we see in support of the SOA product. Many of the recommendations come from the product documentation while others are covered in the SOA Knowledge Base. Our goal is that you will be able to easily identify the areas of concern and understand the guidance available from the output of the Rule Set. Running the health checks for SOA The rules that the checks use are installed with RDA and bundled by product or functional area into what are called 'Rule Sets'. To view the available Rule Sets simply run the command from the RDA home location: rda.cmd (or .sh) -dT hcve This will bring up a list of the available HCVE (Health Check / Verification Engine) Rule Sets. Each Rule Set contains a group of related rules that are used for evalutation and display of results. A rule can be considered synonymous with a single health check and they are assigned an ID, Name and Description that can be seen when they are executed. The Rule Set for SOA is option number 11 and you just enter this selection at the prompt. The Rule Set will then execute to completion. After running an HCVE Rule Set the tool will write the output to the RDA_HOME/output folder. The simplest way to view the output is to drag the .htm file to a browser but of course it can also be uploaded to a Service Request for evaluation by Oracle Support. Many of the Rule Sets will prompt you for information before they can execute their rules but the SOA Rule Set will identify the SOA domains configured in your RDA setup.cfg file. This means that you don't need to answer all of the questions again about where stuff is but it also means that you must have configured RDA for SOA. To run the Rule Set: Download the latest version of RDA from MOS Doc ID 314422.1 Configure RDA for your SOA domains. Detailed steps can be found here In it's simplest form the command is 'rda.cmd (.sh) -S SOA' Go to the RDA home location and enter the command 'rda.cmd (or .sh) -dT hcve' Select option '11' It should be noted that this our first release of a SOA Rule Set so there will probably be some things we need to clean up or fix. None of these rules will actually modify anything on your system as they are read only and do the evaluations internally. Please let us know if you have any issues with the rules or ideas for new ones so we can make them as useful as possible. The Checks Here is a list of the SOA health checks by ID, Name and Description. ID Name Description A00100 SOA Domain Homes Lists the SOA domains that were indentified from the RDA setup.cfg file A00200 Coherence Protocol Conflict Checks to see if you have both Unicast and Multicast configured in the same domain. Checks both the setDomainEnv and config.xml entries (if it exists). We recommend Unicast with fully qualified host names or IP addresses. A00210 Coherence Fully Qualified Host Checks that the host names are fully qualified or that IP addresses are used. Will fail if unqualified host names are detected. A00220 Unicast Local Host Checks that the Coherence localhost is specified for use with Unicast A00300 JTA Timeout Checks that the JTA timeout is configured for the domain and lists the value. The bundled rule will only list the current values of the JTA timeout for each SOA Domain. In the future the rule with fail with a warning if the value is 300 seconds or lower. It is recommended that timeouts follow the pattern 'syncMaxWaitTime' < EJB Timeouts < JTA Timeout. The 300 second value is important because the EJB Timeouts default to 300 seconds. Additional information can be found in MOS Doc ID 880313.1. A00310 XA Max Time Checks that the JTA Maximum XA call time is set for the domain. Fails if it is not explicitly set or if the value is less than or equal to the default of 12000 ms. A00320 XA Timeout Checks that the XA timeout is enabled and that the value is '0' for the SOA Data Source (SOADataSource-jdbc.xml) A00330 JDBC Statement Timeout Checks that the Statement Timeout is set for all SOA Data Sources. Fails if the value is not set or if it is set to the default of -1. A00400 XA Driver Checks that the SOA Data Source is configured to use an XA driver. Fails if it is not. A00410 JDBC Capacity Settings Checks that the minimum and maximum capacity are equal for all SOA Data Sources. Fails if they are not and lists specifically which data sources failed. A00500 SOA Roles Checks that the default SOA roles 'SOAAdmin' and 'SOAOperator' are configured for the soa-infra application in the file sytem-jazn-data.xml. Fails if they are not. A00700 SOA-INFRA Deployment Checks that the soa-infra application is deployed to either a cluster, all members of a cluster or a stand alone server. A00710 SOA Deployments Checks that the SOA related applications are deployed to the same domain members as soa-infra. A00720 SOA Library Deployments Checks that the SOA related libraries are deployed to the same domain members as soa-infra. A00730 Data Source Deployments Checks that the SOA Data Sources are all targeted to the same domain members as soa-infra

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• The first day of JavaOne is already over!

  - by delabassee

  In the past Sunday used to be a more relaxing day with ‘just’ some JavaOne activities going on. Sunday used to be a soft day to prepare yourself for an exhausting week. This is now over as JavaOne is expanding; Sunday is now an integral part of the conference. One of the side effect of this extra day is that some activities related to JavaOne and OpenWorld such as MySQL Connect are being push to start a day earlier on Saturday (can you spot the pattern here?). On the GlassFish front, Sunday was a very busy day! It started at the Moscone Center with the annual GlassFish Community Event where the Java EE 7 and GF 4 roadmaps were presented and discussed. During the event, different GlassFish users such as ZeroTurnaround (the JRebel guys), Grupo RBS and IDR Solutions shared their views on GF, why they like GF but also what could be improved. The event was also a forum for the GF community to exchange with some of the key Java EE / GlassFish Oracle Executives and the different GF team members. The Strategy keynote and the Technical keynote were held in the Masonic Auditorium later in the after-noon. Oracle executives have presented the plans for Java SE, Java FX and Java EE. As on-demand replays will be available soon, I will not summarize several hours of content but here are some personal takeaways from those keynotes. Modularity Modularity is a big deal. We know by now that Project Jigsaw will not be ready for Java SE 8 but in any case, it is already possible (and encouraged) to test Jigsaw today. In the future, Java EE plan to rely on the modularity features provided by Java SE, so Project Jigsaw is also relevant for Java EE developers. Shorter term, to cover some of the modular requirements, Java SE will adopt the approach that was used for Java EE 6 and the notion of Profiles. This approach does not define a module system per say; Profiles is a way to clearly define different subsets of Java SE to fulfill different needs (e.g. the full JRE is not required for a headless application). The introduction of different Profiles, from the Base profile (10mb) to the Full Profile (+50mb), has been proposed for Java SE 8. Embedded Embedded is a strong theme going forward for the Java Plaform. There is now a dedicated program : Java Embedded @ JavaOne Java by nature (e.g. platform independence, built-in security, ability easily talks to any back-end systems, large set of skills available on the market, etc.) is probably the most suited platform for the Internet of Things. You can quickly be up-to-speed and develop services and applications for that space just by using your current Java skills. All you need to start developing on ARM is a 35$ Raspberry Pi ARM board (25$ if you are cheap and can live without an ethernet connection) and the recently released JDK for Linux/ARM. Obviously, GlassFish runs on Raspberry Pi. If you wan to go further in the embedded space, you should take a look Java SE Embedded, an optimized, low footprint, Java environment that support the major embedded architectures (ARM, PPC and x86). Finally, Oracle has recently introduced Java Embedded Suite, a new solution that brings modern middleware capabilities to the embedded space. Java Embedded Suite is an optimized solution that leverage Java SE Embedded but also GlassFish, Jersey and JavaDB to deploy advanced value added capabilities (eg. sensor data filtering and) deeper in the network, closer to the devices. JavaFX JavaFX is going strong! Starting from Java SE 7u6, JavaFX is bundled with the JDK. JavaFX is now available for all the major desktop platforms (Windows, Linux and Mac OS X). JavaFX is now also available, in developer preview, for low end device running Linux/ARM. During the keynote, JavaFX was shown running on a Raspberry Pi! And as announced during the keynote, JavaFX should be fully open-sourced by the end of the year; contributions are welcome!. There is a strong momentum around JavaFX, it’s the ideal client solution for the Java platform. A client layer that works perfectly with GlassFish on the back-end. If you were not convince by JavaFX, it’s time to reconsider it! As an old Chinese proverb say “One tweet is worth a thousand words!” HTML5, Project Avatar and Java EE 7 HTML5 got a lot of airtime too, it was covered during the Java EE 7 section of the keynote. Some details about Project Avatar, Oracle’s incubator project for a TSA (Thin Server Architecture) solution, were diluted and shown during the keynote. On the tooling side, Project Easel running on NetBeans 7.3 beta was demo’ed, including a cool NetBeans debugging session running in Chrome! HTML 5, Project Avatar and Java EE 7 deserve separate posts... Feedback We need your feedback! There are many projects, JSRs and products cooking : GlassFish 4, Project Jigsaw, Concurrency Utilities for Java EE (JSR 236), OpenJFX, OpenJDK to name just a few. Those projects, those specifications will have a profound impact on the Java platform for the years to come! So if you have the opportunity, download, install, learn, tests them and give feedback! Remember, you can "Make the Future Java!" Finally, the traditional GlassFish Party at the Thirsty Bear concluded the first JavaOne day. This party is another place where the community can freely exchange with the GlassFish team in a more relaxed, more friendly (but sometime more noisy) atmosphere. Arun has posted a set of pictures to reflect the atmosphere of the keynotes and the GlassFish party. You can find more details on the others Java EE and GlassFish activities here.

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• SQL SERVER – Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – Part 1 of 2

  - by pinaldave

  Social media has created an Always Connected World for us. Recently I enrolled myself to learn new technologies as a student. I had decided to focus on learning and decided not to stay connected on the internet while I am in the learning session. On the second day of the event after the learning was over, I noticed lots of notification from my friend on my various social media handle. He had connected with me on Twitter, Facebook, Google+, LinkedIn, YouTube as well SMS, WhatsApp on the phone, Skype messages and not to forget with a few emails. I right away called him up. The problem was very unique – let us hear the problem in his own words. “Pinal – we are in big trouble we are not able to figure out what is going on. Our product details table is continuously loosing rows. Lots of rows have disappeared since morning and we are unable to find why the rows are getting deleted. We have made sure that there is no DELETE command executed on the table as well. The matter of the fact, we have removed every single place the code which is referencing the table. We have done so many crazy things out of desperation but no luck. The rows are continuously deleted in a random pattern. Do you think we have problems with intrusion or virus?” After describing the problems he had pasted few rants about why I was not available during the day. I think it will be not smart to post those exact words here (due to many reasons). Well, my immediate reaction was to get online with him. His problem was unique to him and his team was all out to fix the issue since morning. As he said he has done quite a lot out in desperation. I started asking questions from audit, policy management and profiling the data. Very soon I realize that I think this problem was not as advanced as it looked. There was no intrusion, SQL Injection or virus issue. Well, long story short first - It was a very simple issue of foreign key created with ON UPDATE CASCADE and ON DELETE CASCADE.  CASCADE allows deletions or updates of key values to cascade through the tables defined to have foreign key relationships that can be traced back to the table on which the modification is performed. ON DELETE CASCADE specifies that if an attempt is made to delete a row with a key referenced by foreign keys in existing rows in other tables, all rows containing those foreign keys are also deleted. ON UPDATE CASCADE specifies that if an attempt is made to update a key value in a row, where the key value is referenced by foreign keys in existing rows in other tables, all of the foreign key values are also updated to the new value specified for the key. (Reference: BOL) In simple words – due to ON DELETE CASCASE whenever is specified when the data from Table A is deleted and if it is referenced in another table using foreign key it will be deleted as well. In my friend’s case, they had two tables, Products and ProductDetails. They had created foreign key referential integrity of the product id between the table. Now the as fall was up they were updating their catalogue. When they were updating the catalogue they were deleting products which are no more available. As the changes were cascading the corresponding rows were also deleted from another table. This is CORRECT. The matter of the fact, there is no error or anything and SQL Server is behaving how it should be behaving. The problem was in the understanding and inappropriate implementations of business logic.  What they needed was Product Master Table, Current Product Catalogue, and Product Order Details History tables. However, they were using only two tables and without proper understanding the relation between them was build using foreign keys. If there were only two table, they should have used soft delete which will not actually delete the record but just hide it from the original product table. This workaround could have got them saved from cascading delete issues. I will be writing a detailed post on the design implications etc in my future post as in above three lines I cannot cover every issue related to designing and it is also not the scope of the blog post. More about designing in future blog posts. Once they learn their mistake, they were happy as there was no intrusion but trust me sometime we are our own enemy and this is a great example of it. In tomorrow’s blog post we will go over their code and workarounds. Feel free to share your opinions, experiences and comments. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Functional Adaptation

  - by Charles Courchaine

  In real life and OO programming we’re often faced with using adapters, DVI to VGA, 1/4” to 1/8” audio connections, 110V to 220V, wrapping an incompatible interface with a new one, and so on.  Where the adapter pattern is generally considered for interfaces and classes a similar technique can be applied to method signatures.  To be fair, this adaptation is generally used to reduce the number of parameters but I’m sure there are other clever possibilities to be had.  As Jan questioned in the last post, how can we use a common method to execute an action if the action has a differing number of parameters, going back to the greeting example it was suggested having an AddName method that takes a first and last name as parameters.  This is exactly what we’ll address in this post. Let’s set the stage with some review and some code changes.  First, our method that handles the setup/tear-down infrastructure for our WCF service: 1: private static TResult ExecuteGreetingFunc<TResult>(Func<IGreeting, TResult> theGreetingFunc) 2: { 3: IGreeting aGreetingService = null; 4: try 5: { 6: aGreetingService = GetGreetingChannel(); 7: return theGreetingFunc(aGreetingService); 8: } 9: finally 10: { 11: CloseWCFChannel((IChannel)aGreetingService); 12: } 13: } Our original AddName method: 1: private static string AddName(string theName) 2: { 3: return ExecuteGreetingFunc<string>(theGreetingService => theGreetingService.AddName(theName)); 4: } Our new AddName method: 1: private static int AddName(string firstName, string lastName) 2: { 3: return ExecuteGreetingFunc<int>(theGreetingService => theGreetingService.AddName(firstName, lastName)); 4: } Let’s change the AddName method, just a little bit more for this example and have it take the greeting service as a parameter. 1: private static int AddName(IGreeting greetingService, string firstName, string lastName) 2: { 3: return greetingService.AddName(firstName, lastName); 4: } The new signature of AddName using the Func delegate is now Func<IGreeting, string, string, int>, which can’t be used with ExecuteGreetingFunc as is because it expects Func<IGreeting, TResult>.  Somehow we have to eliminate the two string parameters before we can use this with our existing method.  This is where we need to adapt AddName to match what ExecuteGreetingFunc expects, and we’ll do so in the following progression. 1: Func<IGreeting, string, string, int> -> Func<IGreeting, string, int> 2: Func<IGreeting, string, int> -> Func<IGreeting, int>   For the first step, we’ll create a method using the lambda syntax that will “eliminate” the last name parameter: 1: string lastNameToAdd = "Smith"; 2: //Func<IGreeting, string, string, int> -> Func<IGreeting, string, int> 3: Func<IGreeting, string, int> addName = (greetingService, firstName) => AddName(greetingService, firstName, lastNameToAdd); The new addName method gets us one step close to the signature we need.  Let’s say we’re going to call this in a loop to add several names, we’ll take the final step from Func<IGreeting, string, int> -> Func<IGreeting, int> in line as a lambda passed to ExecuteGreetingFunc like so: 1: List<string> firstNames = new List<string>() { "Bob", "John" }; 2: int aID; 3: foreach (string firstName in firstNames) 4: { 5: //Func<IGreeting, string, int> -> Func<IGreeting, int> 6: aID = ExecuteGreetingFunc<int>(greetingService => addName(greetingService, firstName)); 7: Console.WriteLine(GetGreeting(aID)); 8: } If for some reason you needed to break out the lambda on line 6 you could replace it with 1: aID = ExecuteGreetingFunc<int>(ApplyAddName(addName, firstName)); and use this method: 1: private static Func<IGreeting, int> ApplyAddName(Func<IGreeting, string, int> addName, string lastName) 2: { 3: return greetingService => addName(greetingService, lastName); 4: } Splitting out a lambda into its own method is useful both in this style of coding as well as LINQ queries to improve the debugging experience.  It is not strictly necessary to break apart the steps & functions as was shown above; the lambda in line 6 (of the foreach example) could include both the last name and first name instead of being composed of two functions.  The process demonstrated above is one of partially applying functions, this could have also been done with Currying (also see Dustin Campbell’s excellent post on Currying for the canonical curried add example).  Matthew Podwysocki also has some good posts explaining both Currying and partial application and a follow up post that further clarifies the difference between Currying and partial application.  In either technique the ultimate goal is to reduce the number of parameters passed to a function.  Currying makes it a single parameter passed at each step, where partial application allows one to use multiple parameters at a time as we’ve done here.  This technique isn’t for everyone or every problem, but can be extremely handy when you need to adapt a call to something you don’t control.

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• Organization &amp; Architecture UNISA Studies &ndash; Chap 5

  - by MarkPearl

  Learning Outcomes Describe the operation of a memory cell Explain the difference between DRAM and SRAM Discuss the different types of ROM Explain the concepts of a hard failure and a soft error respectively Describe SDRAM organization Semiconductor Main Memory The two traditional forms of RAM used in computers are DRAM and SRAM DRAM (Dynamic RAM) Divided into two technologies… Dynamic Static Dynamic RAM is made with cells that store data as charge on capacitors. The presence or absence of charge in a capacitor is interpreted as a binary 1 or 0. Because capacitors have natural tendency to discharge, dynamic RAM requires periodic charge refreshing to maintain data storage. The term dynamic refers to the tendency of the stored charge to leak away, even with power continuously applied. Although the DRAM cell is used to store a single bit (0 or 1), it is essentially an analogue device. The capacitor can store any charge value within a range, a threshold value determines whether the charge is interpreted as a 1 or 0. SRAM (Static RAM) SRAM is a digital device that uses the same logic elements used in the processor. In SRAM, binary values are stored using traditional flip flop logic configurations. SRAM will hold its data as along as power is supplied to it. Unlike DRAM, no refresh is required to retain data. SRAM vs. DRAM DRAM is simpler and smaller than SRAM. Thus it is more dense and less expensive than SRAM. The cost of the refreshing circuitry for DRAM needs to be considered, but if the machine requires a large amount of memory, DRAM turns out to be cheaper than SRAM. SRAMS are somewhat faster than DRAM, thus SRAM is generally used for cache memory and DRAM is used for main memory. Types of ROM Read Only Memory (ROM) contains a permanent pattern of data that cannot be changed. ROM is non volatile meaning no power source is required to maintain the bit values in memory. While it is possible to read a ROM, it is not possible to write new data into it. An important application of ROM is microprogramming, other applications include library subroutines for frequently wanted functions, System programs, Function tables. A ROM is created like any other integrated circuit chip, with the data actually wired into the chip as part of the fabrication process. To reduce costs of fabrication, we have PROMS. PROMS are… Written only once Non-volatile Written after fabrication Another variation of ROM is the read-mostly memory, which is useful for applications in which read operations are far more frequent than write operations, but for which non volatile storage is required. There are three common forms of read-mostly memory, namely… EPROM EEPROM Flash memory Error Correction Semiconductor memory is subject to errors, which can be classed into two categories… Hard failure – Permanent physical defect so that the memory cell or cells cannot reliably store data Soft failure – Random error that alters the contents of one or more memory cells without damaging the memory (common cause includes power supply issues, etc.) Most modern main memory systems include logic for both detecting and correcting errors. Error detection works as follows… When data is to be read into memory, a calculation is performed on the data to produce a code Both the code and the data are stored When the previously stored word is read out, the code is used to detect and possibly correct errors The error checking provides one of 3 possible results… No errors are detected – the fetched data bits are sent out An error is detected, and it is possible to correct the error. The data bits plus error correction bits are fed into a corrector, which produces a corrected set of bits to be sent out An error is detected, but it is not possible to correct it. This condition is reported Hamming Code See wiki for detailed explanation. We will probably need to know how to do a hemming code – refer to the textbook (pg. 188 – 189) Advanced DRAM organization One of the most critical system bottlenecks when using high-performance processors is the interface to main memory. This interface is the most important pathway in the entire computer system. The basic building block of main memory remains the DRAM chip. In recent years a number of enhancements to the basic DRAM architecture have been explored, and some of these are now on the market including… SDRAM (Synchronous DRAM) DDR-DRAM RDRAM SDRAM (Synchronous DRAM) SDRAM exchanges data with the processor synchronized to an external clock signal and running at the full speed of the processor/memory bus without imposing wait states. SDRAM employs a burst mode to eliminate the address setup time and row and column line precharge time after the first access In burst mode a series of data bits can be clocked out rapidly after the first bit has been accessed SDRAM has a multiple bank internal architecture that improves opportunities for on chip parallelism SDRAM performs best when it is transferring large blocks of data serially There is now an enhanced version of SDRAM known as double data rate SDRAM or DDR-SDRAM that overcomes the once-per-cycle limitation of SDRAM

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• Anatomy of a .NET Assembly - CLR metadata 2

  - by Simon Cooper

  Before we look any further at the CLR metadata, we need a quick diversion to understand how the metadata is actually stored. Encoding table information As an example, we'll have a look at a row in the TypeDef table. According to the spec, each TypeDef consists of the following: Flags specifying various properties of the class, including visibility. The name of the type. The namespace of the type. What type this type extends. The field list of this type. The method list of this type. How is all this data actually represented? Offset & RID encoding Most assemblies don't need to use a 4 byte value to specify heap offsets and RIDs everywhere, however we can't hard-code every offset and RID to be 2 bytes long as there could conceivably be more than 65535 items in a heap or more than 65535 fields or types defined in an assembly. So heap offsets and RIDs are only represented in the full 4 bytes if it is required; in the header information at the top of the #~ stream are 3 bits indicating if the #Strings, #GUID, or #Blob heaps use 2 or 4 bytes (the #US stream is not accessed from metadata), and the rowcount of each table. If the rowcount for a particular table is greater than 65535 then all RIDs referencing that table throughout the metadata use 4 bytes, else only 2 bytes are used. Coded tokens Not every field in a table row references a single predefined table. For example, in the TypeDef extends field, a type can extend another TypeDef (a type in the same assembly), a TypeRef (a type in a different assembly), or a TypeSpec (an instantiation of a generic type). A token would have to be used to let us specify the table along with the RID. Tokens are always 4 bytes long; again, this is rather wasteful of space. Cutting the RID down to 2 bytes would make each token 3 bytes long, which isn't really an optimum size for computers to read from memory or disk. However, every use of a token in the metadata tables can only point to a limited subset of the metadata tables. For the extends field, we only need to be able to specify one of 3 tables, which we can do using 2 bits: 0x0: TypeDef 0x1: TypeRef 0x2: TypeSpec We could therefore compress the 4-byte token that would otherwise be needed into a coded token of type TypeDefOrRef. For each type of coded token, the least significant bits encode the table the token points to, and the rest of the bits encode the RID within that table. We can work out whether each type of coded token needs 2 or 4 bytes to represent it by working out whether the maximum RID of every table that the coded token type can point to will fit in the space available. The space available for the RID depends on the type of coded token; a TypeOrMethodDef coded token only needs 1 bit to specify the table, leaving 15 bits available for the RID before a 4-byte representation is needed, whereas a HasCustomAttribute coded token can point to one of 18 different tables, and so needs 5 bits to specify the table, only leaving 11 bits for the RID before 4 bytes are needed to represent that coded token type. For example, a 2-byte TypeDefOrRef coded token with the value 0x0321 has the following bit pattern: 0 3 2 1 0000 0011 0010 0001 The first two bits specify the table - TypeRef; the other bits specify the RID. Because we've used the first two bits, we've got to shift everything along two bits: 000000 1100 1000 This gives us a RID of 0xc8. If any one of the TypeDef, TypeRef or TypeSpec tables had more than 16383 rows (2^14 - 1), then 4 bytes would need to be used to represent all TypeDefOrRef coded tokens throughout the metadata tables. Lists The third representation we need to consider is 1-to-many references; each TypeDef refers to a list of FieldDef and MethodDef belonging to that type. If we were to specify every FieldDef and MethodDef individually then each TypeDef would be very large and a variable size, which isn't ideal. There is a way of specifying a list of references without explicitly specifying every item; if we order the MethodDef and FieldDef tables by the owning type, then the field list and method list in a TypeDef only have to be a single RID pointing at the first FieldDef or MethodDef belonging to that type; the end of the list can be inferred by the field list and method list RIDs of the next row in the TypeDef table. Going back to the TypeDef If we have a look back at the definition of a TypeDef, we end up with the following reprensentation for each row: Flags - always 4 bytes Name - a #Strings heap offset. Namespace - a #Strings heap offset. Extends - a TypeDefOrRef coded token. FieldList - a single RID to the FieldDef table. MethodList - a single RID to the MethodDef table. So, depending on the number of entries in the heaps and tables within the assembly, the rows in the TypeDef table can be as small as 14 bytes, or as large as 24 bytes. Now we've had a look at how information is encoded within the metadata tables, in the next post we can see how they are arranged on disk.

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