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• Agile Like Jazz

  - by Jeff Certain

  (I’ve been sitting on this for a week or so now, thinking that it needed to be tightened up a bit to make it less rambling. Since that’s clearly not going to happen, reader beware!) I had the privilege of spending around 90 minutes last night sitting and listening to Sonny Rollins play a concert at the Disney Center in LA. If you don’t know who Sonny Rollins is, I don’t know how to explain the experience; if you know who he is, I don’t need to. Suffice it to say that he has been recording professionally for over 50 years, and helped create an entire genre of music. A true master by any definition. One of the most intriguing aspects of a concert like this, however, is watching the master step aside and let the rest of the musicians play. Not just play their parts, but really play… letting them take over the spotlight, to strut their stuff, to soak up enthusiastic applause from the crowd. Maybe a lot of it has to do with the fact that Sonny Rollins has been doing this for more than a half-century. Maybe it has something to do with a kind of patience you learn when you’re on the far side of 80 – and the man can still blow a mean sax for 90 minutes without stopping! Maybe it has to do with the fact that he was out there for the love of the music and the love of the show, not because he had anything to prove to anyone and, I like to think, not for the money. Perhaps it had more to do with the fact that, when you’re at that level of mastery, the other musicians are going to be good. Really good. Whatever the reasons, there was a incredible freedom on that stage – the ability to improvise, for each musician to showcase their own specialization and skills, and them come back to the common theme, back to being on the same page, as it were. All this took place in the same venue that is home to the L.A. Phil. Somehow, I can’t ever see the same kind of free-wheeling improvisation happening in that context. And, since I’m a geek, I started thinking about agility. Rollins has put together a quintet that reflects his own particular style and past. No upright bass or piano for Rollins – drums, bongos, electric guitar and bass guitar along with his sax. It’s not about the mix of instruments. Other trios, quartets, and sextets use different mixes of instruments. New Orleans jazz tends towards trombones instead of sax; some prefer cornet or trumpet. But no matter what the choice of instruments, size matters. Team sizes are something I’ve been thinking about for a while. We’re on a quest to rethink how our teams are organized. They just feel too big, too unwieldy. In fact, they really don’t feel like teams at all. Most of the time, they feel more like collections or people who happen to report to the same manager. I attribute this to a couple factors. One is over-specialization; we have a tendency to have people work in silos. Although the teams are product-focused, within them our developers are both generalists and specialists. On the one hand, we expect them to be able to build an entire vertical slice of the application; on the other hand, each developer tends to be responsible for the vertical slice. As a result, developers often work on their own piece of the puzzle, in isolation. This sort of feels like working on a jigsaw in a group – each person taking a set of colors and piecing them together to reveal a portion of the overall picture. But what inevitably happens when you go to meld all those pieces together? Inevitably, you have some sections that are too big to move easily. These sections end up falling apart under their own weight as you try to move them. Not only that, but there are other challenges – figuring out where that section fits, and how to tie it into the rest of the puzzle. Often, this is when you find a few pieces need to be added – these pieces are “glue,” if you will. The other issue that arises is due to the overhead of maintaining communications in a team. My mother, who worked in IT for around 30 years, once told me that 20% per team member is a good rule of thumb for maintaining communication. While this is a rule of thumb, it seems to imply that any team over about 6 people is going to become less agile simple because of the communications burden. Teams of ten or twelve seem like they fall into the philharmonic organizational model. Complicated pieces of music requiring dozens of players to all be on the same page requires a much different model than the jazz quintet. There’s much less room for improvisation, originality or freedom. (There are probably orchestral musicians who will take exception to this characterization; I’m calling it like I see it from the cheap seats.) And, there’s one guy up front who is running the show, whose job is to keep all of those dozens of players on the same page, to facilitate communications. Somehow, the orchestral model doesn’t feel much like a self-organizing team, either. The first violin may be the best violinist in the orchestra, but they don’t get to perform free-wheeling solos. I’ve never heard of an orchestra getting together for a jam session. But I have heard of teams that organize their work based on the developers available, rather than organizing the developers based on the work required. I have heard of teams where desired functionality is deferred – or worse yet, schedules are missed – because one critical person doesn’t have any bandwidth available. I’ve heard of teams where people simply don’t have the big picture, because there is too much communication overhead for everyone to be aware of everything that is happening on a project. I once heard Paul Rayner say something to the effect of “you have a process that is perfectly designed to give you exactly the results you have.” Given a choice, I want a process that’s much more like jazz than orchestral music. I want a process that doesn’t burden me with lots of forms and checkboxes and stuff. Give me the simplest, most lightweight process that will work – and a smaller team of the best developers I can find. This seems like the kind of process that will get the kind of result I want to be part of.

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• ASP.NET MVC 3 Hosting :: Error Handling and CustomErrors in ASP.NET MVC 3 Framework

  - by C. Miller

  So, what else is new in MVC 3? MVC 3 now has a GlobalFilterCollection that is automatically populated with a HandleErrorAttribute. This default FilterAttribute brings with it a new way of handling errors in your web applications. In short, you can now handle errors inside of the MVC pipeline. What does that mean? This gives you direct programmatic control over handling your 500 errors in the same way that ASP.NET and CustomErrors give you configurable control of handling your HTTP error codes. How does that work out? Think of it as a routing table specifically for your Exceptions, it's pretty sweet! Global Filters The new Global.asax file now has a RegisterGlobalFilters method that is used to add filters to the new GlobalFilterCollection, statically located at System.Web.Mvc.GlobalFilter.Filters. By default this method adds one filter, the HandleErrorAttribute. public class MvcApplication : System.Web.HttpApplication {     public static void RegisterGlobalFilters(GlobalFilterCollection filters)     {         filters.Add(new HandleErrorAttribute());     } HandleErrorAttributes The HandleErrorAttribute is pretty simple in concept: MVC has already adjusted us to using Filter attributes for our AcceptVerbs and RequiresAuthorization, now we are going to use them for (as the name implies) error handling, and we are going to do so on a (also as the name implies) global scale. The HandleErrorAttribute has properties for ExceptionType, View, and Master. The ExceptionType allows you to specify what exception that attribute should handle. The View allows you to specify which error view (page) you want it to redirect to. Last but not least, the Master allows you to control which master page (or as Razor refers to them, Layout) you want to render with, even if that means overriding the default layout specified in the view itself. public class MvcApplication : System.Web.HttpApplication {     public static void RegisterGlobalFilters(GlobalFilterCollection filters)     {         filters.Add(new HandleErrorAttribute         {             ExceptionType = typeof(DbException),             // DbError.cshtml is a view in the Shared folder.             View = "DbError",             Order = 2         });         filters.Add(new HandleErrorAttribute());     }Error Views All of your views still work like they did in the previous version of MVC (except of course that they can now use the Razor engine). However, a view that is used to render an error can not have a specified model! This is because they already have a model, and that is System.Web.Mvc.HandleErrorInfo @model System.Web.Mvc.HandleErrorInfo           @{     ViewBag.Title = "DbError"; } <h2>A Database Error Has Occurred</h2> @if (Model != null) {     <p>@Model.Exception.GetType().Name<br />     thrown in @Model.ControllerName @Model.ActionName</p> }Errors Outside of the MVC Pipeline The HandleErrorAttribute will only handle errors that happen inside of the MVC pipeline, better known as 500 errors. Errors outside of the MVC pipeline are still handled the way they have always been with ASP.NET. You turn on custom errors, specify error codes and paths to error pages, etc. It is important to remember that these will happen for anything and everything outside of what the HandleErrorAttribute handles. Also, these will happen whenever an error is not handled with the HandleErrorAttribute from inside of the pipeline. <system.web>  <customErrors mode="On" defaultRedirect="~/error">     <error statusCode="404" redirect="~/error/notfound"></error>  </customErrors>Sample Controllers public class ExampleController : Controller {     public ActionResult Exception()     {         throw new ArgumentNullException();     }     public ActionResult Db()     {         // Inherits from DbException         throw new MyDbException();     } } public class ErrorController : Controller {     public ActionResult Index()     {         return View();     }     public ActionResult NotFound()     {         return View();     } } Putting It All Together If we have all the code above included in our MVC 3 project, here is how the following scenario's will play out: 1.       A controller action throws an Exception. You will remain on the current page and the global HandleErrorAttributes will render the Error view. 2.       A controller action throws any type of DbException. You will remain on the current page and the global HandleErrorAttributes will render the DbError view. 3.       Go to a non-existent page. You will be redirect to the Error controller's NotFound action by the CustomErrors configuration for HTTP StatusCode 404. But don't take my word for it, download the sample project and try it yourself. Three Important Lessons Learned For the most part this is all pretty straight forward, but there are a few gotcha's that you should remember to watch out for: 1) Error views have models, but they must be of type HandleErrorInfo. It is confusing at first to think that you can't control the M in an MVC page, but it's for a good reason. Errors can come from any action in any controller, and no redirect is taking place, so the view engine is just going to render an error view with the only data it has: The HandleError Info model. Do not try to set the model on your error page or pass in a different object through a controller action, it will just blow up and cause a second exception after your first exception! 2) When the HandleErrorAttribute renders a page, it does not pass through a controller or an action. The standard web.config CustomErrors literally redirect a failed request to a new page. The HandleErrorAttribute is just rendering a view, so it is not going to pass through a controller action. But that's ok! Remember, a controller's job is to get the model for a view, but an error already has a model ready to give to the view, thus there is no need to pass through a controller. That being said, the normal ASP.NET custom errors still need to route through controllers. So if you want to share an error page between the HandleErrorAttribute and your web.config redirects, you will need to create a controller action and route for it. But then when you render that error view from your action, you can only use the HandlerErrorInfo model or ViewData dictionary to populate your page. 3) The HandleErrorAttribute obeys if CustomErrors are on or off, but does not use their redirects. If you turn CustomErrors off in your web.config, the HandleErrorAttributes will stop handling errors. However, that is the only configuration these two mechanisms share. The HandleErrorAttribute will not use your defaultRedirect property, or any other errors registered with customer errors. In Summary The HandleErrorAttribute is for displaying 500 errors that were caused by exceptions inside of the MVC pipeline. The custom errors are for redirecting from error pages caused by other HTTP codes.

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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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• Learnings from trying to write better software: Loud errors from the very start

  - by theo.spears

  Microsoft made a very small number of backwards incompatible changes between .NET 1.1 and 2.0, because they wanted to make it as easy and safe as possible to port applications to the new runtime. (Here’s a list.) However, one thing they did change was what happens when a background thread fails with an unhanded exception - in .NET 1.1 nothing happened, the thread terminated, and the application continued oblivious. Try the same trick in .NET 2.0 and the entire application, including all threads, will rudely terminate. There are three reasons for this. Firstly if a background thread has crashed, it may have left the entire application in an inconsistent state, in a way that will affect other threads. It’s better to terminate the entire application than continue and have the application perform actions based on a broken state, for example take customer orders, or write corrupt files to disk.  Secondly, during software development, it is far better for errors to be loud and obtrusive. Even if you have unit tests and integration tests (and you should), a key part of ensuring software works properly is to actually try using it, both through systematic testing and through the casual use all software gets by its developers during use. Subtle errors are easy to miss if you are not actually doing real work using the application, loud errors are obvious. Thirdly, and most importantly, even if catching and swallowing exceptions indiscriminately doesn't cause any problems in your application, the presence of unexpected exceptions shows you do not fully understand the behavior of your code. The currently released version of your application may be absolutely correct. However, because your mental model of the behavior is wrong, any future change you make to the program could and probably will introduce critical errors.  This applies to more than just exceptions causing threads to exit, any unexpected state should make the application blow up in an un-ignorable way. The worst thing you can do is silently swallow errors and continue. And let's be clear, writing to a log file does not count as blowing up in an un-ignorable way.  This is all simple as long as the call stack only contains your code, but when your functions start to be called by third party or .NET framework code, it's surprisingly easy for exceptions to start vanishing. Let's look at two examples.   1. Windows forms drag drop events  Usually if you throw an exception from a winforms event handler it will bring up the "application has crashed" dialog with abort and continue options. This is a good default behavior - the error is big and loud, but it is possible for the user to ignore the error and hopefully save their data, if somehow this bug makes it past testing. However drag and drop are different - throw an exception from one of these and it will just be silently swallowed with no explanation.  By the way, it's not just drag and drop events. Timer events do it too.  You can research how exceptions are treated in different handlers and code appropriately, but the safest and most user friendly approach is to always catch exceptions in your event handlers and show your own error message. I'll talk about one good approach to handling these exceptions at the end of this post.   2. SSMS integration for SQL Tab Magic  A while back wrote an SSMS add-in called SQL Tab Magic (learn more about the process here). It works by listening to certain SSMS events and remembering what documents are opened and closed. I deployed it internally and it was used for a few months by a number of people without problems, so I was reasonably confident in its quality. Before releasing I made a few cleanups, including introducing error reporting. Bam. A few days later I was looking at over 1,000 error reports in my inbox. In turns out I wasn't handling table designers properly. The exceptions were there, but again SSMS was helpfully swallowing them all for me, so I was blissfully unaware. Had I made my errors loud from the start, I would have noticed these issues long before and fixed them.   Handling exceptions  Now you are systematically catching exceptions throughout your application, you need to do something with them. I've tried 3 options: log them, alert the user, and automatically send them home.  There are a few good options for logging in .NET. The most widespread is Apache log4net, which provides a very capable and configurable logging framework. There is also NLog which has a compatible interface, with a greater emphasis on fluent rather than XML configuration.  Alerting the user serves two purposes. Firstly it means they understand their action has failed to they don't just assume it worked (Silent file copy failure is a problem if you then delete the originals) or that they should keep waiting for a background task to complete. Secondly, it means the users can report the bug to your support team, and then you can fix it. This means the message you show the user should contain the information you need as a developer to identify and fix it. And the user will probably just send you a screenshot of the dialog, so it shouldn't be hidden by scroll bars.  This leads us to the third option, automatically sending error reports home. By automatic I mean with minimal effort on the part of the user, rather than doing it silently behind their backs. The advantage of this is you can send back far more detailed and precise information than you can expect a user to include in an email, and by making it easier to report errors, you make it more likely users will do so.  We do this using a great tool called SmartAssembly (full disclosure: this is a product made by Red Gate). It captures complete stack traces including the values of all local variables and then allows the user to send all this information back with a single click. We also capture log files to help understand what lead up to the error. We then use the free SmartAssembly Sync for Jira to dedupe these reports and raise them as bugs in our bug tracking system.  The combined effect of loud errors during development and then automatic error reporting once software is deployed allows us to find and fix more bugs, correct misunderstandings on how our software works, and overall is a key piece in delivering higher quality software. However it is no substitute for having motivated cunning testers in the building - and we're looking to hire more of those too.   If you found this post interesting you should follow me on twitter.  

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• Google Analytics on Android

  - by pjv

  There is a specific and official analytics SDK for native Android apps (note that I'm not talking about webpages in apps on a phone). This library basically sends pages and events to Google Analytics and you can view your analytics in exactly the same dashboard as for websites. Since my background is apps rather than websites, and since a lot of the Google Analytics terminology seems particularly inapplicable to a native app, I need some pointers. Please discuss my remarks, provide some clarification where you think I'm off-track, and above all share good experiences! 1. Page Views Pages mostly can match different Activities (and Dialogs) being displayed. Activities can be visible behind non-full-screen Activities however, though only the top-level Activity can be interacted. This sort-off clashes with a "(page) view". You'd also want at least one page view for each visit and therefore put one page view tracker in the Application class. However this does not constitute a window or sorts. Usually an Activity will open at the same time, so the time spent on that page will have been 0. This will influence your "time spent" statistics. How are these counted anyway? Moreover, there is a loose coupling between the Activities, by means of Intents. A user can, much like on any website, step in at any Activity, although usually this then concerns resuming the application where he left off. This makes that the hierarchy of Activities usually is very flat. And since there are no url's involved. What meaning would using slashes in page titles have, such as "/Home"? All pages would appear on an equal level in the reports, so no content drilldown. Non-unique page views seem to be counted as some kind of indicator of successfulness: how often does the visitor revisit the page. When the user rotates the screen however usually an Activity resumes again, thus making it a new page view. This happens a lot. Maybe a well-thought-through placement of the call might solve this, or placing several, I'm not sure. How to deal with Page Views? 2. Events I'd say there are two sorts: A user event Something that happened, usually as an indirect consequence of the above. The latter particularly is giving me headaches. First of all, many events aren't written in code any more, but pieced logically together by means of Intents. This means that there is no place to put the analytics call. You'd either have to give up this advantage and start doing it the old-fashioned way in favor of good analytics, or, just be missing some events. Secondly, as a developer you're not so much interested in when a user clicks a button, but if the action that should have been performed really was performed and what the result was. There seems to be no clear way to get resulting data into Google Analytics (what's up with the integers? I want to put in Strings!). The same that applies to the flat pages hierarchy, also goes for the event categories. You could do "vertical" categories (topically, that is), but some code is shared "horizontally" and the tracking will be equally shared. Just as with the Intents mechanism, inheritance makes it hard for you to put the tracking in the right places at all times. And I can't really imagine "horizontal" categories. Unless you start making really small categories, such as all the items form the same menu in one category, I have a hard time grasping the concept. Finally, how do you deal with cancelling? Usually you both have an explicit cancel mechanism by ways of a button, as well as the implicit cancel when the "back"-button is pressed to leave the activity and there were no changes. The latter also applies to "saves", when the back button is pressed and there ARE changes. How are you consequently going to catch all these if not by doing all the "back"-button work yourself? How to deal with events? 3. Goals For goal types I have choice of: URL Destination, Time on Site, and Pages/Visit. Most apps don't have a funnel that leads the user to some "registration done" or "order placed" page. Apps have either already been bought (in which case you want to stimulate the user to love your app, so that he might bring on new buyers) or are paid for by in-app ads. So URL Destination is not a very important goal. Time on Site also seems troublesome. First, I have some doubt on how this would be measured. Second, I don't necessarily want my user to spend a lot of time in my already paid app, just be active and content. Equivalently, why not mention how frequent a user uses your app? Regarding Pages/Visit I already mentioned how screen orientation changes blow up the page view numbers. In an app I'd be most interested in events/visit to measure the user's involvement/activity. If he's intensively using the app then he must be loving it right? Furthermore, I also have some small funnels (that do not lead to conversion though) that I want to see streamlined. In my mind those funnels would end in events rather than page views but that seems not to be possible. I could also measure clickthroughs on in-app ads, but then I'd need to track those as Page Views rather than Events, in view of "URL Destination". What are smart goals for apps and how can you fit them on top of Analytics? 4. Optimisation Is there a smart way to manually do what "Website Optimiser" does for websites? Most importantly, how would I track different landing page designs? 5. Traffic Sources Referrals deal with installation time referrals, if you're smart enough to get them included. But perhaps I'd also want to get some data which third-party app sends users to my app to perform some actions (this app interoperability is possible via Intents). Many of the terminologies related to "Traffic Sources" seem totally meaningless and there is no possibility of connecting in AdSense. What are smart uses of this data? 6. Visitors Of the "Browser capabilities", "Network Properties" and "Mobile" tabs, many things are pointless as they have no influence on / relation with my mostly offline app that won't use flash anyway. Only if you drill down far enough, can you get to OS versions, which do matter a lot. I even forgot where you could check what exact Android devices visited. What are smart uses of this data? How can you make the relevant info more prominent? 7. Other No in-page analytics. I have to register my app as a web-url (What!?)?

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• Strange WCF Error - IIS hosted - context being aborted

  - by RandomNoob

  I have a WCF service that does some document conversions and returns the document to the caller. When developing locally on my local dev server, the service is hosted on ASP.NET Development server, a console application invokes the operation and executes within seconds. When I host the service in IIS via a .svc file, two of the documents work correctly, the third one bombs out, it begins to construct the word document using the OpenXml Sdk, but then just dies. I think this has something to do with IIS, but I cannot put my finger on it. There are a total of three types of documents I generate. In a nutshell this is how it works SQL 2005 DB/IBM DB2 - WCF Service written by other developer to expose data. This service only has one endpoint using basicHttpBinding My Service invokes his service, gets the relevant data, uses the Open Xml Sdk to generate a Microsoft Word Document, saves it on a server and returns the path to the user. The word documents are no bigger than 100KB. I am also using basicHttpBinding although I have tried wsHttpBinding with the same results. What is amazing is how fast it is locally, and even more that two of the documents generate just fine, its the third document type that refuses to work. To the error message: An error occured while receiving the HTTP Response to http://myservername.mydomain.inc/MyService/Service.Svc. This could be due to the service endpoint binding not using the HTTP Protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the server shutting down). See server logs for more details. I have spent the last 2 days trying to figure out what is going on, I have tried everything, including changing the maxReceivedMessageSize, maxBufferSize, maxBufferPoolSize, etc etc to large values, I even included: <httpRuntime maxRequestLength="2097151" executionTimeout="120"/> To see maybe if IIS was choking because of that. Programatically the service does nothing special, it just constructs the word documents from the data using the Open Xml Sdk and like I said, locally all 3 documents work when invoked via a console app running locally on the asp.net dev server, i.e. http://localhost:3332/myService.svc When I host it on IIS and I try to get a Windows Forms application to invoke it, I get the error. I know you will ask for logs, so yes I have logging enabled on my Host. And there is no error in the logs, I am logging everything. Basically I invoke two service operations written by another developer. MyOperation calls - HisOperation1 and then HisOperation2, both of those calls give me complex types. I am going to look at his code tomorrow, because he is using LINQ2SQL and there may be some funny business going on there. He is using a variety of collections etc, but the fact that I can run the exact same document, lets call it "Document 3" within seconds when the service is being hosted locally on ASP WebDev Server is what is most odd, why would it run on scaled down Cassini and blow up on IIS? From the log it seems, after calling HisOperation1 and HisOperation2 the service just goes into la-la land dies, there is a application pool (w3wp.exe) error in the Windows Event Log. Faulting application w3wp.exe, version 6.0.3790.1830, stamp 42435be1, faulting module kernel32.dll, version 5.2.3790.3311, stamp 49c5225e, debug? 0, fault address 0x00015dfa. It's classified as .NET 2.0 Runtime error. Any help is appreciated, the lack of sleep is getting to me. Help me Obi-Wan Kenobi, you're my only hope.

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• Contructor parameters for dependent classes with Unity Framework

  - by Onisemus

  I just started using the Unity Application Block to try to decouple my classes and make it easier for unit testing. I ran into a problem though that I'm not sure how to get around. Looked through the documentation and did some Googling but I'm coming up dry. Here's the situation: I have a facade-type class which is a chat bot. It is a singleton class which handles all sort of secondary classes and provides a central place to launch and configure the bot. I also have a class called AccessManager which, well, manages access to bot commands and resources. Boiled down to the essence, I have the classes set up like so. public class Bot { public string Owner { get; private set; } public string WorkingDirectory { get; private set; } private IAccessManager AccessManager; private Bot() { // do some setup // LoadConfig sets the Owner & WorkingDirectory variables LoadConfig(); // init the access mmanager AccessManager = new MyAccessManager(this); } public static Bot Instance() { // singleton code } ... } And the AccessManager class: public class MyAccessManager : IAccessManager { private Bot botReference; public MyAccesManager(Bot botReference) { this.botReference = botReference; SetOwnerAccess(botReference.Owner); } private void LoadConfig() { string configPath = Path.Combine( botReference.WorkingDirectory, "access.config"); // do stuff to read from config file } ... } I would like to change this design to use the Unity Application Block. I'd like to use Unity to generate the Bot singleton and to load the AccessManager interface in some sort of bootstrapping method that runs before anything else does. public static void BootStrapSystem() { IUnityContainer container = new UnityContainer(); // create new bot instance Bot newBot = Bot.Instance(); // register bot instance container.RegisterInstance<Bot>(newBot); // register access manager container.RegisterType<IAccessManager,MyAccessManager>(newBot); } And when I want to get a reference to the Access Manager inside the Bot constructor I can just do: IAcessManager accessManager = container.Resolve<IAccessManager>(); And elsewhere in the system to get a reference to the Bot singleton: // do this Bot botInstance = container.Resolve<Bot>(); // instead of this Bot botInstance = Bot.Instance(); The problem is the method BootStrapSystem() is going to blow up. When I create a bot instance it's going to try to resolve IAccessManager but won't be able to because I haven't registered the types yet (that's the next line). But I can't move the registration in front of the Bot creation because as part of the registration I need to pass the Bot as a parameter! Circular dependencies!! Gah!!! This indicates to me I have a flaw in the way I have this structured. But how do I fix it? Help!!

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• iPhone Memory Error - when using Build & Debug, How to debug?

  - by LonH99

  I'm a newbie and need some help with an iPhone App running on the Simulator. The app works fine running with Build & Run or Build & Run - breakpoints off, but blows when running with Build & Debug - Breakpoints on. Any help or thoughts would be greatly appreciated. Lon Specifics: No breakpoints set, never gets to any visible simulator results, seems to blow during initialization phase before it can generate any output. Source of app is the DrinkMixer example, in the "Head First iPhone development" book (example built up to page 280) by Dan & Tracey Pilone. Blows With this Error Message: Attaching to process 970. Pending breakpoint 1 - "*0x01c1b001" resolved Program received signal: “EXC_BAD_ACCESS”. No memory available to program now: unsafe to call malloc Data Formatters temporarily unavailable, will re-try after a 'continue'. (Not safe to call dlopen at this time.) No memory available to program now: unsafe to call malloc --- Leaks: The only object noted as "leaked Object" is: Leaked Object # Address Size Responsible Library Responsible Frame Malloc 128 Bytes <blank> 0x3c11950 128Bytes CoreGraphics open_handle_to_dylib_path ___ Object Allocations shows (Highest at top = CFString): Category --- Overall Bytes -- #Overall -- Live Bytes -- #Living * All Allocations * 497kb #5888 496kb #5878 10 CFString 42kb #1126 42kb Malloc 32.00 KB 32kb #1 32kb Malloc 1.00 KB 29kb #29 29kb Malloc 8.00 KB 24kb #3 24kb Malloc 32 Bytes 20.81kb #666 20.75kb Malloc 1.50 KB 19.5kb #13 19.5kb CFDictionary (key-store) 17.64kb #159 17.64kb (note: Except for "All Allocations, the #Living is the same as #Overall) --- List of Calls from Debugger: #0 0x01c1b010 in CFStringCreateByCombiningStrings #1 0x023a0779 in LoadFontPathCache #2 0x023a096b in Initialize #3 0x023a0f3e in GSFontCreateWithName #4 0x003d4575 in +[UIFont boldSystemFontOfSize:] #5 0x002cddaa in +[UINavigationButton defaultFont] #6 0x002d9e37 in -[UINavigationButton initWithValue:width:style:barStyle:possibleTitles:tintColor:] #7 0x002cdc75 in -[UINavigationButton initWithImage:width:style:] #8 0x00468eeb in -[UIBarButtonItem(Static) createViewForNavigationItem:] #9 0x002d1b56 in -[UINavigationItem customRightView] #10 0x002d20e3 in -[UINavigationItem updateNavigationBarButtonsAnimated:] #11 0x002d1e1a in -[UINavigationItem setRightBarButtonItem:] #12 0x00002e7b in -[RootViewController viewDidLoad] at RootViewController.m:41 #13 0x00313796 in -[UIViewController view] #14 0x00311d92 in -[UIViewController contentScrollView] #15 0x0031c2b4 in -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:] #16 0x0031b32e in -[UINavigationController _layoutViewController:] #17 0x0031cd1a in -[UINavigationController _startTransition:fromViewController:toViewController:] #18 0x0031831a in -[UINavigationController _startDeferredTransitionIfNeeded] #19 0x004362e4 in -[UILayoutContainerView layoutSubviews] #20 0x035342b0 in -[CALayer layoutSublayers] #21 0x0353406f in CALayerLayoutIfNeeded #22 0x035338c6 in CA::Context::commit_transaction #23 0x0353353a in CA::Transaction::commit #24 0x00295ef9 in -[UIApplication _reportAppLaunchFinished] #25 0x0029bb88 in -[UIApplication handleEvent:withNewEvent:] #26 0x002976d3 in -[UIApplication sendEvent:] #27 0x0029e0b5 in _UIApplicationHandleEvent #28 0x023a3ed1 in PurpleEventCallback #29 0x01bb6b80 in CFRunLoopRunSpecific #30 0x01bb5c48 in CFRunLoopRunInMode #31 0x00295e69 in -[UIApplication _run] #32 0x0029f003 in UIApplicationMain #33 0x00002ba0 in main at main.m:14 The code, including line #41 (noted below) is as follows. And thanks for the formatting help and comment: import "RootViewController.h" import "DrinkDetailViewController.h"; import "DrinkConstants.h" import "AddDrinkViewController.h" @implementation RootViewController @synthesize drinks, addButtonItem; - (void)viewDidLoad { [super viewDidLoad]; // add PATH for PLIST NSString *path = [[NSBundle mainBundle] pathForResource: @"DrinkDirections" ofType:@"plist"]; NSMutableArray *tmpArray = [[NSMutableArray alloc] initWithContentsOfFile:path]; self.drinks = tmpArray; [tmpArray release]; // Next is Line #41 - I removed earlier empty lines & Comments self.navigationItem.rightBarButtonItem = self.addButtonItem; } - (IBAction) addButtonPressed: (id) sender { NSLog(@"Add button pressed!");

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• How do I maximize code coverage?

  - by naivedeveloper

  Hey all, the following is a snippet of code taken from the unix ptx utility. I'm attempting to maximize code coverage on this utility, but I am unable to reach the indicated portion of code. Admittedly, I'm not as strong in my C skills as I used to be. The portion of code is indicated with comments, but it is towards the bottom of the block. if (used_length == allocated_length) { allocated_length += (1 << SWALLOW_REALLOC_LOG); block->start = (char *) xrealloc (block->start, allocated_length); } Any help interpreting the indicated portion in order to cover that block would be greatly appreciated. /* Reallocation step when swallowing non regular files. The value is not the actual reallocation step, but its base two logarithm. */ #define SWALLOW_REALLOC_LOG 12 static void swallow_file_in_memory (const char *file_name, BLOCK *block) { int file_handle; /* file descriptor number */ struct stat stat_block; /* stat block for file */ size_t allocated_length; /* allocated length of memory buffer */ size_t used_length; /* used length in memory buffer */ int read_length; /* number of character gotten on last read */ /* As special cases, a file name which is NULL or "-" indicates standard input, which is already opened. In all other cases, open the file from its name. */ bool using_stdin = !file_name || !*file_name || strcmp (file_name, "-") == 0; if (using_stdin) file_handle = STDIN_FILENO; else if ((file_handle = open (file_name, O_RDONLY)) < 0) error (EXIT_FAILURE, errno, "%s", file_name); /* If the file is a plain, regular file, allocate the memory buffer all at once and swallow the file in one blow. In other cases, read the file repeatedly in smaller chunks until we have it all, reallocating memory once in a while, as we go. */ if (fstat (file_handle, &stat_block) < 0) error (EXIT_FAILURE, errno, "%s", file_name); if (S_ISREG (stat_block.st_mode)) { size_t in_memory_size; block->start = (char *) xmalloc ((size_t) stat_block.st_size); if ((in_memory_size = read (file_handle, block->start, (size_t) stat_block.st_size)) != stat_block.st_size) { error (EXIT_FAILURE, errno, "%s", file_name); } block->end = block->start + in_memory_size; } else { block->start = (char *) xmalloc ((size_t) 1 << SWALLOW_REALLOC_LOG); used_length = 0; allocated_length = (1 << SWALLOW_REALLOC_LOG); while (read_length = read (file_handle, block->start + used_length, allocated_length - used_length), read_length > 0) { used_length += read_length; /* Cannot cover from this point...*/ if (used_length == allocated_length) { allocated_length += (1 << SWALLOW_REALLOC_LOG); block->start = (char *) xrealloc (block->start, allocated_length); } /* ...to this point. */ } if (read_length < 0) error (EXIT_FAILURE, errno, "%s", file_name); block->end = block->start + used_length; } /* Close the file, but only if it was not the standard input. */ if (! using_stdin && close (file_handle) != 0) error (EXIT_FAILURE, errno, "%s", file_name); }

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• How to reserve public API to internal usage in .NET?

  - by mark

  Dear ladies and sirs. Let me first present the case, which will explain my question. This is going to be a bit long, so I apologize in advance :-). I have objects and collections, which should support the Merge API (it is my custom API, the signature of which is immaterial for this question). This API must be internal, meaning only my framework should be allowed to invoke it. However, derived types should be able to override the basic implementation. The natural way to implement this pattern as I see it, is this: The Merge API is declared as part of some internal interface, let us say IMergeable. Because the interface is internal, derived types would not be able to implement it directly. Rather they must inherit it from a common base type. So, a common base type is introduced, which would implement the IMergeable interface explicitly, where the interface methods delegate to respective protected virtual methods, providing the default implementation. This way the API is only callable by my framework, but derived types may override the default implementation. The following code snippet demonstrates the concept: internal interface IMergeable { void Merge(object obj); } public class BaseFrameworkObject : IMergeable { protected virtual void Merge(object obj) { // The default implementation. } void IMergeable.Merge(object obj) { Merge(obj); } } public class SomeThirdPartyObject : BaseFrameworkObject { protected override void Merge(object obj) { // A derived type implementation. } } All is fine, provided a single common base type suffices, which is usually true for non collection types. The thing is that collections must be mergeable as well. Collections do not play nicely with the presented concept, because developers do not develop collections from the scratch. There are predefined implementations - observable, filtered, compound, read-only, remove-only, ordered, god-knows-what, ... They may be developed from scratch in-house, but once finished, they serve wide range of products and should never be tailored to some specific product. Which means, that either: they do not implement the IMergeable interface at all, because it is internal to some product the scope of the IMergeable interface is raised to public and the API becomes open and callable by all. Let us refer to these collections as standard collections. Anyway, the first option screws my framework, because now each possible standard collection type has to be paired with the respective framework version, augmenting the standard with the IMergeable interface implementation - this is so bad, I am not even considering it. The second option breaks the framework as well, because the IMergeable interface should be internal for a reason (whatever it is) and now this interface has to open to all. So what to do? My solution is this. make IMergeable public API, but add an extra parameter to the Merge method, I call it a security token. The interface implementation may check that the token references some internal object, which is never exposed to the outside. If this is the case, then the method was called from within the framework, otherwise - some outside API consumer attempted to invoke it and so the implementation can blow up with a SecurityException. Here is the modified code snippet demonstrating this concept: internal static class InternalApi { internal static readonly object Token = new object(); } public interface IMergeable { void Merge(object obj, object token); } public class BaseFrameworkObject : IMergeable { protected virtual void Merge(object obj) { // The default implementation. } public void Merge(object obj, object token) { if (!object.ReferenceEquals(token, InternalApi.Token)) { throw new SecurityException("bla bla bla"); } Merge(obj); } } public class SomeThirdPartyObject : BaseFrameworkObject { protected override void Merge(object obj) { // A derived type implementation. } } Of course, this is less explicit than having an internally scoped interface and the check is moved from the compile time to run time, yet this is the best I could come up with. Now, I have a gut feeling that there is a better way to solve the problem I have presented. I do not know, may be using some standard Code Access Security features? I have only vague understanding of it, but can LinkDemand attribute be somehow related to it? Anyway, I would like to hear other opinions. Thanks.

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• The How-To Geek Holiday Gift Guide (Geeky Stuff We Like)

  - by The Geek

  Welcome to the very first How-To Geek Holiday Gift Guide, where we’ve put together a list of our absolute favorites to help you weed through all of the junk out there to pick the perfect gift for anybody. Though really, it’s just a list of the geeky stuff we want. We’ve got a whole range of items on the list, from cheaper gifts that most anybody can afford, to the really expensive stuff that we’re pretty sure nobody is giving us. Stocking Stuffers Here’s a couple of ideas for items that won’t break the bank. LED Keychain Micro-Light   Magcraft 1/8-Inch Rare Earth Cube Magnets Best little LED keychain light around. If they don’t need the penknife of the above item this is the perfect gift. I give them out by the handfuls and nobody ever says anything but good things about them. I’ve got ones that are years old and still running on the same battery.  Price: $8   Geeks cannot resist magnets. Jason bought this pack for his fridge because he was sick of big clunky magnets… these things are amazing. One tiny magnet, smaller than an Altoid mint, can practically hold a clipboard right to the fridge. Amazing. I spend more time playing with them on the counter than I do actually hanging stuff.  Price: $10 Lots of Geeky Mugs   Astronomy Powerful Green Laser Pointer There’s loads of fun, geeky mugs you can find on Amazon or anywhere else—and they are great choices for the geek who loves their coffee. You can get the Caffeine mug pictured here, or go with an Atari one, Canon Lens, or the Aperture mug based on Portal. Your choice. Price: $7   No, it’s not a light saber, but it’s nearly bright enough to be one—you can illuminate low flying clouds at night or just blind some aliens on your day off. All that for an extremely low price. Loads of fun. Price: $15       Geeky TV Shows and Books Sometimes you just want to relax and enjoy a some TV or a good book. Here’s a few choices. The IT Crowd Fourth Season   Doctor Who, Complete Fifth Series Ridiculous, funny show about nerds in the IT department, loved by almost all the geeks here at HTG. Justin even makes this required watching for new hires in his office so they’ll get his jokes. You can pre-order the fourth season, or pick up seasons one, two, or three for even cheaper. Price: $13   It doesn’t get any more nerdy than Eric’s pick, the fifth all-new series of Doctor Who, where the Daleks are hatching a new master plan from the heart of war-torn London. There’s also alien vampires, humanoid reptiles, and a lot more. Price: $52 Battlestar Galactica Complete Series   MAKE: Electronics: Learning Through Discovery Watch the epic fight to save the human race by finding the fabled planet Earth while being hunted by the robotic Cylons. You can grab the entire series on DVD or Blu-ray, or get the seasons individually. This isn’t your average sci-fi TV show. Price: $150 for Blu-ray.   Want to learn the fundamentals of electronics in a fun, hands-on way? The Make:Electronics book helps you build the circuits and learn how it all works—as if you had any more time between all that registry hacking and loading software on your new PC. Price: $21       Geeky Gadgets for the Gadget-Loving Geek Here’s a few of the items on our gadget list, though lets be honest: geeks are going to love almost any gadget, especially shiny new ones. Klipsch Image S4i Premium Noise-Isolating Headset with 3-Button Apple Control   GP2X Caanoo MAME/Console Emulator If you’re a real music geek looking for some serious quality in the headset for your iPhone or iPod, this is the pair that Alex recommends. They aren’t terribly cheap, but you can get the less expensive S3 earphones instead if you prefer. Price: $50-100   Eric says: “As an owner of an older version, I can say the GP2X is one of my favorite gadgets ever. Touted a “Retro Emulation Juggernaut,” GP2X runs Linux and may be the only open source software console available. Sounds too good to be true, but isn’t.” Price: $150 Roku XDS Streaming Player 1080p   Western Digital WD TV Live Plus HD Media Player If you do a lot of streaming over Netflix, Hulu Plus, Amazon’s Video on Demand, Pandora, and others, the Roku box is a great choice to get your content on your TV without paying a lot of money.  It’s also got Wireless-N built in, and it supports full 1080P HD. Price: $99   If you’ve got a home media collection sitting on a hard drive or a network server, the Western Digital box is probably the cheapest way to get that content on your TV, and it even supports Netflix streaming too. It’ll play loads of formats in full HD quality. Price: $99 Fujitsu ScanSnap S300 Color Mobile Scanner   Doxie, the amazing scanner for documents Trevor said: “This wonderful little scanner has become absolutely essential to me. My desk used to just be a gigantic pile of papers that I didn’t need at the moment, but couldn’t throw away ‘just in case.’ Now, every few weeks, I’ll run that paper pile through this and then happily shred the originals!” Price: $300   If you don’t scan quite as often and are looking for a budget scanner you can throw into your bag, or toss into a drawer in your desk, the Doxie scanner is a great alternative that I’ve been using for a while. It’s half the price, and while it’s not as full-featured as the Fujitsu, it might be a better choice for the very casual user. Price: $150       (Expensive) Gadgets Almost Anybody Will Love If you’re not sure that one of the more geeky presents is gonna work, here’s some gadgets that just about anybody is going to love, especially if they don’t have one already. Of course, some of these are a bit on the expensive side—but it’s a wish list, right? Amazon Kindle       The Kindle weighs less than a paperback book, the screen is amazing and easy on the eyes, and get ready for the kicker: the battery lasts at least a month. We aren’t kidding, either—it really lasts that long. If you don’t feel like spending money for books, you can use it to read PDFs, and if you want to get really geeky, you can hack it for custom screensavers. Price: $139 iPod Touch or iPad       You can’t go wrong with either of these presents—the iPod Touch can do almost everything the iPhone can do, including games, apps, and music, and it has the same Retina display as the iPhone, HD video recording, and a front-facing camera so you can use FaceTime. Price: $229+, depending on model. The iPad is a great tablet for playing games, browsing the web, or just using on your coffee table for guests. It’s well worth buying one—but if you’re buying for yourself, keep in mind that the iPad 2 is probably coming out in 3 months. Price: $500+ MacBook Air  The MacBook Air comes in 11” or 13” versions, and it’s an amazing little machine. It’s lightweight, the battery lasts nearly forever, and it resumes from sleep almost instantly. Since it uses an SSD drive instead of a hard drive, you’re barely going to notice any speed problems for general use. So if you’ve got a lot of money to blow, this is a killer gift. Price: $999 and up. Stuck with No Idea for a Present? Gift Cards! Yeah, you’re not going to win any “thoughtful present” awards with these, but you might just give somebody what they really want—the new Angry Birds HD for their iPad, Cut the Rope, or anything else they want. ITunes Gift Card   Amazon.com Gift Card Somebody in your circle getting a new iPod, iPhone, or iPad? You can get them an iTunes gift card, which they can use to buy music, games or apps. Yep, this way you can gift them a copy of Angry Birds if they don’t already have it. Or even Cut the Rope.   No clue what to get somebody on your list? Amazon gift cards let them buy pretty much anything they want, from organic weirdberries to big screen TVs. Yeah, it’s not as thoughtful as getting them a nice present, but look at the bright side: maybe they’ll get you an Amazon gift card and it’ll balance out. That’s the highlights from our lists—got anything else to add? Share your geeky gift ideas in the comments. Latest Features How-To Geek ETC The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor Our Favorite Tech: What We’re Thankful For at How-To Geek The How-To Geek Guide to Learning Photoshop, Part 7: Design and Typography Happy Snow Bears Theme for Chrome and Iron [Holiday] Download Full Command and Conquer: Tiberian Sun Game for Free Scorched Cometary Planet Wallpaper Quick Fix: Add the RSS Button Back to the Firefox Awesome Bar Dropbox Desktop Client 1.0.0 RC for Windows, Linux, and Mac Released Hang in There Scrat! – Ice Age Wallpaper

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• Taming Hopping Windows

  - by Roman Schindlauer

  At first glance, hopping windows seem fairly innocuous and obvious. They organize events into windows with a simple periodic definition: the windows have some duration d (e.g. a window covers 5 second time intervals), an interval or period p (e.g. a new window starts every 2 seconds) and an alignment a (e.g. one of those windows starts at 12:00 PM on March 15, 2012 UTC). var wins = xs     .HoppingWindow(TimeSpan.FromSeconds(5),                    TimeSpan.FromSeconds(2),                    new DateTime(2012, 3, 15, 12, 0, 0, DateTimeKind.Utc)); Logically, there is a window with start time a + np and end time a + np + d for every integer n. That’s a lot of windows. So why doesn’t the following query (always) blow up? var query = wins.Select(win => win.Count()); A few users have asked why StreamInsight doesn’t produce output for empty windows. Primarily it’s because there is an infinite number of empty windows! (Actually, StreamInsight uses DateTimeOffset.MaxValue to approximate “the end of time” and DateTimeOffset.MinValue to approximate “the beginning of time”, so the number of windows is lower in practice.) That was the good news. Now the bad news. Events also have duration. Consider the following simple input: var xs = this.Application                 .DefineEnumerable(() => new[]                     { EdgeEvent.CreateStart(DateTimeOffset.UtcNow, 0) })                 .ToStreamable(AdvanceTimeSettings.IncreasingStartTime); Because the event has no explicit end edge, it lasts until the end of time. So there are lots of non-empty windows if we apply a hopping window to that single event! For this reason, we need to be careful with hopping window queries in StreamInsight. Or we can switch to a custom implementation of hopping windows that doesn’t suffer from this shortcoming. The alternate window implementation produces output only when the input changes. We start by breaking up the timeline into non-overlapping intervals assigned to each window. In figure 1, six hopping windows (“Windows”) are assigned to six intervals (“Assignments”) in the timeline. Next we take input events (“Events”) and alter their lifetimes (“Altered Events”) so that they cover the intervals of the windows they intersect. In figure 1, you can see that the first event e1 intersects windows w1 and w2 so it is adjusted to cover assignments a1 and a2. Finally, we can use snapshot windows (“Snapshots”) to produce output for the hopping windows. Notice however that instead of having six windows generating output, we have only four. The first and second snapshots correspond to the first and second hopping windows. The remaining snapshots however cover two hopping windows each! While in this example we saved only two events, the savings can be more significant when the ratio of event duration to window duration is higher. Figure 1: Timeline The implementation of this strategy is straightforward. We need to set the start times of events to the start time of the interval assigned to the earliest window including the start time. Similarly, we need to modify the end times of events to the end time of the interval assigned to the latest window including the end time. The following snap-to-boundary function that rounds a timestamp value t down to the nearest value t' <= t such that t' is a + np for some integer n will be useful. For convenience, we will represent both DateTime and TimeSpan values using long ticks: static long SnapToBoundary(long t, long a, long p) {     return t - ((t - a) % p) - (t > a ? 0L : p); } How do we find the earliest window including the start time for an event? It’s the window following the last window that does not include the start time assuming that there are no gaps in the windows (i.e. duration < interval), and limitation of this solution. To find the end time of that antecedent window, we need to know the alignment of window ends: long e = a + (d % p); Using the window end alignment, we are finally ready to describe the start time selector: static long AdjustStartTime(long t, long e, long p) {     return SnapToBoundary(t, e, p) + p; } To find the latest window including the end time for an event, we look for the last window start time (non-inclusive): public static long AdjustEndTime(long t, long a, long d, long p) {     return SnapToBoundary(t - 1, a, p) + p + d; } Bringing it together, we can define the translation from events to ‘altered events’ as in Figure 1: public static IQStreamable<T> SnapToWindowIntervals<T>(IQStreamable<T> source, TimeSpan duration, TimeSpan interval, DateTime alignment) {     if (source == null) throw new ArgumentNullException("source");     // reason about DateTime and TimeSpan in ticks     long d = Math.Min(DateTime.MaxValue.Ticks, duration.Ticks);     long p = Math.Min(DateTime.MaxValue.Ticks, Math.Abs(interval.Ticks));     // set alignment to earliest possible window     var a = alignment.ToUniversalTime().Ticks % p;     // verify constraints of this solution     if (d <= 0L) { throw new ArgumentOutOfRangeException("duration"); }     if (p == 0L || p > d) { throw new ArgumentOutOfRangeException("interval"); }     // find the alignment of window ends     long e = a + (d % p);     return source.AlterEventLifetime(         evt => ToDateTime(AdjustStartTime(evt.StartTime.ToUniversalTime().Ticks, e, p)),         evt => ToDateTime(AdjustEndTime(evt.EndTime.ToUniversalTime().Ticks, a, d, p)) -             ToDateTime(AdjustStartTime(evt.StartTime.ToUniversalTime().Ticks, e, p))); } public static DateTime ToDateTime(long ticks) {     // just snap to min or max value rather than under/overflowing     return ticks < DateTime.MinValue.Ticks         ? new DateTime(DateTime.MinValue.Ticks, DateTimeKind.Utc)         : ticks > DateTime.MaxValue.Ticks         ? new DateTime(DateTime.MaxValue.Ticks, DateTimeKind.Utc)         : new DateTime(ticks, DateTimeKind.Utc); } Finally, we can describe our custom hopping window operator: public static IQWindowedStreamable<T> HoppingWindow2<T>(     IQStreamable<T> source,     TimeSpan duration,     TimeSpan interval,     DateTime alignment) {     if (source == null) { throw new ArgumentNullException("source"); }     return SnapToWindowIntervals(source, duration, interval, alignment).SnapshotWindow(); } By switching from HoppingWindow to HoppingWindow2 in the following example, the query returns quickly rather than gobbling resources and ultimately failing! public void Main() {     var start = new DateTimeOffset(new DateTime(2012, 6, 28), TimeSpan.Zero);     var duration = TimeSpan.FromSeconds(5);     var interval = TimeSpan.FromSeconds(2);     var alignment = new DateTime(2012, 3, 15, 12, 0, 0, DateTimeKind.Utc);     var events = this.Application.DefineEnumerable(() => new[]     {         EdgeEvent.CreateStart(start.AddSeconds(0), "e0"),         EdgeEvent.CreateStart(start.AddSeconds(1), "e1"),         EdgeEvent.CreateEnd(start.AddSeconds(1), start.AddSeconds(2), "e1"),         EdgeEvent.CreateStart(start.AddSeconds(3), "e2"),         EdgeEvent.CreateStart(start.AddSeconds(9), "e3"),         EdgeEvent.CreateEnd(start.AddSeconds(3), start.AddSeconds(10), "e2"),         EdgeEvent.CreateEnd(start.AddSeconds(9), start.AddSeconds(10), "e3"),     }).ToStreamable(AdvanceTimeSettings.IncreasingStartTime);     var adjustedEvents = SnapToWindowIntervals(events, duration, interval, alignment);     var query = from win in HoppingWindow2(events, duration, interval, alignment)                 select win.Count();     DisplayResults(adjustedEvents, "Adjusted Events");     DisplayResults(query, "Query"); } As you can see, instead of producing a massive number of windows for the open start edge e0, a single window is emitted from 12:00:15 AM until the end of time: Adjusted Events StartTime EndTime Payload 6/28/2012 12:00:01 AM 12/31/9999 11:59:59 PM e0 6/28/2012 12:00:03 AM 6/28/2012 12:00:07 AM e1 6/28/2012 12:00:05 AM 6/28/2012 12:00:15 AM e2 6/28/2012 12:00:11 AM 6/28/2012 12:00:15 AM e3 Query StartTime EndTime Payload 6/28/2012 12:00:01 AM 6/28/2012 12:00:03 AM 1 6/28/2012 12:00:03 AM 6/28/2012 12:00:05 AM 2 6/28/2012 12:00:05 AM 6/28/2012 12:00:07 AM 3 6/28/2012 12:00:07 AM 6/28/2012 12:00:11 AM 2 6/28/2012 12:00:11 AM 6/28/2012 12:00:15 AM 3 6/28/2012 12:00:15 AM 12/31/9999 11:59:59 PM 1 Regards, The StreamInsight Team

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• The Internet of Things & Commerce: Part 3 -- Interview with Kristen J. Flanagan, Commerce Product Management

  - by Katrina Gosek, Director | Commerce Product Strategy-Oracle

  Internet of Things & Commerce Series: Part 3 (of 3) And now for the final installment my three part series on the Internet of Things & Commerce. Post one, “The Next 7,000 Days”, introduced the idea of the Internet of Things, followed by a second post interviewing one of our chief commerce innovation strategists, Brian Celenza.  This final post in the series is an interview with Kristen J. Flanagan, lead product manager for Oracle Commerce omnichannel strategy. She takes us through the past, present, and future of how our Commerce Solution is re-imagining the way physical and digital shopping come together. ------- QUESTION: It’s your job to stay on top of what our customers’ need to not only run their online businesses effectively, but also to make sure they have product capabilities they can innovate and grow on. What key trend has been top-of-mind for you and our customers around this collision of physical and digital shopping? Kristen: I’ll agree with Brian Celenza that hands down mobile has forced a major disruption in shopping and selling behavior. A few years ago, mobile exploded at a pace I don't think anyone was expecting. Early on, we saw our customers scrambling to establish a mobile presence---mostly through "screen scraping" technologies. As smartphones continued to advance (at lightening speed!), our customers started to investigate ways to truly tap in to their eCommerce capabilities to deliver the mobile experience. They started looking to us for a means of using the eCommerce services and capabilities to deliver a mobile experience that is tailored for mobile rather than the desktop experience on a smaller screen. In the future, I think we'll see customers starting to really understand what their shoppers need and expect from a mobile offering and how they can adapt their content and delivery of that content to meet those needs. And, mobile shopping doesn’t stop at the consumer / buyer. Because the in-store experience is compelling and has advantages that digital just can't offer, we're also starting to see the eCommerce services being leveraged for mobile for in-store sales associates. Brick-and-mortar retailers are interested in putting the omnichannel product catalog, promotions, and cart into the hands of knowledgeable associates. Retailers are now looking to connect and harness the eCommerce data in-store so that shoppers have a reason to walk-in. I think we'll be seeing a lot more customers thinking about melding the in-store and digital experiences to present a richer offering for shoppers.    QUESTION: What are some examples of what our customers are doing currently to bring these concepts to reality? Kristen: Well, without question, connecting digital and brick-and-mortar worlds is becoming tablestakes for selling experiences. If a brand has a foot in both worlds (i.e., isn’t a pureplay online retailer), they have to connect the dots because shoppers – whether consumers or B2B buyers –don't think in clearly defined channels anymore. The expectation is connectedness – for on- and offline experiences, promotions, products, and customer data. What does this mean practically for businesses selling goods on- and offline? It touches a lot of systems: inventory info on the eCommerce site, fulfillment options across channels (buy online/pickup in store), order information (representing various channels for a cohesive view of shopper order history), promotions across digital and store, etc.  A few years ago, the main link between store and digital was the smartphone. We all remember when “apps” became a thing and many of our customers were scrambling to get a native app out there. Now we're seeing more strategic thinking around the benefits of mobile web vs. native and how that ties in to the purpose and role of mobile within the digital channel. Put it more broadly, how these pieces fit together in the overall brand puzzle.  The same could be said for “showrooming.” Where it was a major concern (i.e., shoppers using stores to look at merchandise and then order online from Amazon), in recent months, it’s emerged that the inverse is now becoming a a reality as well. "Webrooming" (using digital sites to do research before making a purchase in the store) is a new behavior pure play retailers are challenged with. There are many technologies, behaviors, and information that need to tie together to offer a holistic omnichannel shopping experience. As a result, brands are looking for ways to connect the digital and in-store experiences to bridge the gaps: shared assortments across channels, assisted selling apps that arm associates with information about shoppers, shared promotions, inventory, etc. QUESTION: How has Oracle Commerce been built to help brands make the link between in-store and digital over the last few years? Kristen: Over the last seven years, the product has been in step with the changes in industry needs. Here is a brief history of the evolution: Prior to Oracle’s acquisition of ATG and Endeca, key investments were made to cross-channel functionality that we are still building on today. Commerce Service Center (v2007.1) ATG introduced the Commerce Service Center in 2007.1 and marked the first entry into what was then called “cross-channel.” The Commerce Service Center is a call-center-agent-facing application that enables agents to see shopper orders, online catalog, promotions, and pricing. It is tightly integrated with the eCommerce capabilities of the platform and commerce engine and provided a means of connecting data from the call center and online channels.  REST services framework (v9.1)  In v9.1 we introduced the REST services framework and interface in the Platform that enabled customers to use ATG web services in other applications. This framework has become the basis for our subsequent omni-channel features and functionality. Multisite Architecture (v10) With the v10 release, we introduced the Multisite Architecture, which enabled customers to manage multiple sites (and channels) within a single instance of the BCC. Customers could create site- and channel-specific catalogs, promotions, targeters, and scenarios. Endeca Page Builder (2.x) / Experience Manager (3.x) With the introduction of Endeca for Mobile (now part of the core platform, available through the reference store – see blow) on top of Page Builder (and then eventually Experience Manager), Endeca gave business users the tools to create and manage native and mobile web applications. And since the acquisition of both ATG (2011) and Endeca (2012), Oracle Commerce has leveraged the best of each leading technology’s capabilities for omnichannel commerce to continue to drive innovation for our customers. Service enablement of core Oracle Commerce capabilities (v10.1.1, 10.2, & 11) After the establishment of the REST services framework and interface, we followed up in subsequent releases with service enablement of core Oracle Commerce capabilities throughout the iOS native app and the enablement of the core Commerce Service Center features. The result is that customers can leverage these services for their integrations with other systems, as well as their omnichannel initiatives.  Mobile web reference application (v10.1) In 10.1 we introduced the shopper-facing mobile reference application that showed how to use Oracle Commerce to deliver a mobile web experience for shoppers. This included the use of Experience Manager and cartridges to drive those experiences on select pages.  Native (iOS) reference application (v10.1.1)  We came out with the 10.1.1 shopper-facing native iOS ref app that illustrated how to use the Commerce REST services to deliver an iOS app. Also included Experience Manager-driven pages.   Assisted Selling reference application (v10.2.1)  The Assisted Selling reference application is our first reference application designed for the in-store associate. This iOS app shows customers how they can use Oracle Commerce data and information to provide a high-touch, consultative sales environment as well as to put the endless aisle into hands of their associates. Shoppers can start a cart online, and in-store associates can access that cart via the application to provide more information or add products and then transact using the ATG engine. Support for Retail promotions (v11) As part of the v11 release, we worked with teams in the Oracle Retail Global Business Unit (RGBU) to assess which promotion types and capabilities are supported across our products. Those products included Oracle Commerce, Oracle Point of Service (ORPOS), and Oracle Retail Price Management (RPM). The result is that customers can now more easily support omnichannel use cases between the store and digital.  Making sure Oracle Commerce can help support the omnichannel needs of our customers is core to our product strategy. With 89% of consumers now use two or more channels to make a single purchase, ensuring that cross-channel interactions are linked is critical to a great customer experience – and to sales. As Oracle Commerce evolves, we want to make it simple for organizations to create, deliver, and scale experiences across touchpoints with our create once, deploy commerce anywhere framework. We have a flexible, services-oriented architecture that allows data, content, catalogs, cart, experiences, personalization, and merchandising to be shared across touchpoints and easily extended in to new environments like mobile, social, in-store, Call Center, and new Websites. [For the latest downloads and Oracle Commerce documentation, please visit the Oracle Technical Network.] ------ Thank you to both Brian and Kristen for their contributions and to this blog series and their continued thought leadership for Oracle Commerce. We are all looking forward to the coming years of months of new shopping behaviors and opportunities to innovate. Because – if the digital fabric of our everyday lives continues to change at the same pace – the next five years (that just under 2,000 days), will be dramatic. ---------- THIS DOCUMENT IS FOR INFORMATIONAL PURPOSES ONLY AND MAY NOT BE INCORPORATED INTO A CONTRACT OR AGREEMENT

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• Developing Schema Compare for Oracle (Part 2): Dependencies

  - by Simon Cooper

  In developing Schema Compare for Oracle, one of the issues we came across was the size of the databases. As detailed in my last blog post, we had to allow schema pre-filtering due to the number of objects in a standard Oracle database. Unfortunately, this leads to some quite tricky situations regarding object dependencies. This post explains how we deal with these dependencies. 1. Cross-schema dependencies Say, in the following database, you're populating SchemaA, and synchronizing SchemaA.Table1: SOURCE   TARGET CREATE TABLE SchemaA.Table1 ( Col1 NUMBER REFERENCES SchemaB.Table1(Col1));   CREATE TABLE SchemaA.Table1 ( Col1 VARCHAR2(100) REFERENCES SchemaB.Table1(Col1)); CREATE TABLE SchemaB.Table1 ( Col1 NUMBER PRIMARY KEY);   CREATE TABLE SchemaB.Table1 ( Col1 VARCHAR2(100) PRIMARY KEY); We need to do a rebuild of SchemaA.Table1 to change Col1 from a VARCHAR2(100) to a NUMBER. This consists of: Creating a table with the new schema Inserting data from the old table to the new table, with appropriate conversion functions (in this case, TO_NUMBER) Dropping the old table Rename new table to same name as old table Unfortunately, in this situation, the rebuild will fail at step 1, as we're trying to create a NUMBER column with a foreign key reference to a VARCHAR2(100) column. As we're only populating SchemaA, the naive implementation of the object population prefiltering (sticking a WHERE owner = 'SCHEMAA' on all the data dictionary queries) will generate an incorrect sync script. What we actually have to do is: Drop foreign key constraint on SchemaA.Table1 Rebuild SchemaB.Table1 Rebuild SchemaA.Table1, adding the foreign key constraint to the new table This means that in order to generate a correct synchronization script for SchemaA.Table1 we have to know what SchemaB.Table1 is, and that it also needs to be rebuilt to successfully rebuild SchemaA.Table1. SchemaB isn't the schema that the user wants to synchronize, but we still have to load the table and column information for SchemaB.Table1 the same way as any table in SchemaA. Fortunately, Oracle provides (mostly) complete dependency information in the dictionary views. Before we actually read the information on all the tables and columns in the database, we can get dependency information on all the objects that are either pointed at by objects in the schemas we’re populating, or point to objects in the schemas we’re populating (think about what would happen if SchemaB was being explicitly populated instead), with a suitable query on all_constraints (for foreign key relationships) and all_dependencies (for most other types of dependencies eg a function using another function). The extra objects found can then be included in the actual object population, and the sync wizard then has enough information to figure out the right thing to do when we get to actually synchronize the objects. Unfortunately, this isn’t enough. 2. Dependency chains The solution above will only get the immediate dependencies of objects in populated schemas. What if there’s a chain of dependencies? A.tbl1 -> B.tbl1 -> C.tbl1 -> D.tbl1 If we’re only populating SchemaA, the implementation above will only include B.tbl1 in the dependent objects list, whereas we might need to know about C.tbl1 and D.tbl1 as well, in order to ensure a modification on A.tbl1 can succeed. What we actually need is a graph traversal on the dependency graph that all_dependencies represents. Fortunately, we don’t have to read all the database dependency information from the server and run the graph traversal on the client computer, as Oracle provides a method of doing this in SQL – CONNECT BY. So, we can put all the dependencies we want to include together in big bag with UNION ALL, then run a SELECT ... CONNECT BY on it, starting with objects in the schema we’re populating. We should end up with all the objects that might be affected by modifications in the initial schema we’re populating. Good solution? Well, no. For one thing, it’s sloooooow. all_dependencies, on my test databases, has got over 110,000 rows in it, and the entire query, for which Oracle was creating a temporary table to hold the big bag of graph edges, was often taking upwards of two minutes. This is too long, and would only get worse for large databases. But it had some more fundamental problems than just performance. 3. Comparison dependencies Consider the following schema: SOURCE   TARGET CREATE TABLE SchemaA.Table1 ( Col1 NUMBER REFERENCES SchemaB.Table1(col1));   CREATE TABLE SchemaA.Table1 ( Col1 VARCHAR2(100)); CREATE TABLE SchemaB.Table1 ( Col1 NUMBER PRIMARY KEY);   CREATE TABLE SchemaB.Table1 ( Col1 VARCHAR2(100)); What will happen if we used the dependency algorithm above on the source & target database? Well, SchemaA.Table1 has a foreign key reference to SchemaB.Table1, so that will be included in the source database population. On the target, SchemaA.Table1 has no such reference. Therefore SchemaB.Table1 will not be included in the target database population. In the resulting comparison of the two objects models, what you will end up with is: SOURCE  TARGET SchemaA.Table1 -> SchemaA.Table1 SchemaB.Table1 -> (no object exists) When this comparison is synchronized, we will see that SchemaB.Table1 does not exist, so we will try the following sequence of actions: Create SchemaB.Table1 Rebuild SchemaA.Table1, with foreign key to SchemaB.Table1 Oops. Because the dependencies are only followed within a single database, we’ve tried to create an object that already exists. To fix this we can include any objects found as dependencies in the source or target databases in the object population of both databases. SchemaB.Table1 will then be included in the target database population, and we won’t try and create objects that already exist. All good? Well, consider the following schema (again, only explicitly populating SchemaA, and synchronizing SchemaA.Table1): SOURCE   TARGET CREATE TABLE SchemaA.Table1 ( Col1 NUMBER REFERENCES SchemaB.Table1(col1));   CREATE TABLE SchemaA.Table1 ( Col1 VARCHAR2(100)); CREATE TABLE SchemaB.Table1 ( Col1 NUMBER PRIMARY KEY);   CREATE TABLE SchemaB.Table1 ( Col1 VARCHAR2(100) PRIMARY KEY); CREATE TABLE SchemaC.Table1 ( Col1 NUMBER);   CREATE TABLE SchemaC.Table1 ( Col1 VARCHAR2(100) REFERENCES SchemaB.Table1); Although we’re now including SchemaB.Table1 on both sides of the comparison, there’s a third table (SchemaC.Table1) that we don’t know about that will cause the rebuild of SchemaB.Table1 to fail if we try and synchronize SchemaA.Table1. That’s because we’re only running the dependency query on the schemas we’re explicitly populating; to solve this issue, we would have to run the dependency query again, but this time starting the graph traversal from the objects found in the other database. Furthermore, this dependency chain could be arbitrarily extended.This leads us to the following algorithm for finding all the dependencies of a comparison: Find initial dependencies of schemas the user has selected to compare on the source and target Include these objects in both the source and target object populations Run the dependency query on the source, starting with the objects found as dependents on the target, and vice versa Repeat 2 & 3 until no more objects are found For the schema above, this will result in the following sequence of actions: Find initial dependenciesSchemaA.Table1 -> SchemaB.Table1 found on sourceNo objects found on target Include objects in both source and targetSchemaB.Table1 included in source and target Run dependency query, starting with found objectsNo objects to start with on sourceSchemaB.Table1 -> SchemaC.Table1 found on target Include objects in both source and targetSchemaC.Table1 included in source and target Run dependency query on found objectsNo objects found in sourceNo objects to start with in target Stop This will ensure that we include all the necessary objects to make any synchronization work. However, there is still the issue of query performance; the CONNECT BY on the entire database dependency graph is still too slow. After much sitting down and drawing complicated diagrams, we decided to move the graph traversal algorithm from the server onto the client (which turned out to run much faster on the client than on the server); and to ensure we don’t read the entire dependency graph onto the client we also pull the graph across in bits – we start off with dependency edges involving schemas selected for explicit population, and whenever the graph traversal comes across a dependency reference to a schema we don’t yet know about a thunk is hit that pulls in the dependency information for that schema from the database. We continue passing more dependent objects back and forth between the source and target until no more dependency references are found. This gives us the list of all the extra objects to populate in the source and target, and object population can then proceed. 4. Object blacklists and fast dependencies When we tested this solution, we were puzzled in that in some of our databases most of the system schemas (WMSYS, ORDSYS, EXFSYS, XDB, etc) were being pulled in, and this was increasing the database registration and comparison time quite significantly. After debugging, we discovered that the culprits were database tables that used one of the Oracle PL/SQL types (eg the SDO_GEOMETRY spatial type). These were creating a dependency chain from the database tables we were populating to the system schemas, and hence pulling in most of the system objects in that schema. To solve this we introduced blacklists of objects we wouldn’t follow any dependency chain through. As well as the Oracle-supplied PL/SQL types (MDSYS.SDO_GEOMETRY, ORDSYS.SI_COLOR, among others) we also decided to blacklist the entire PUBLIC and SYS schemas, as any references to those would likely lead to a blow up in the dependency graph that would massively increase the database registration time, and could result in the client running out of memory. Even with these improvements, each dependency query was taking upwards of a minute. We discovered from Oracle execution plans that there were some columns, with dependency information we required, that were querying system tables with no indexes on them! To cut a long story short, running the following query: SELECT * FROM all_tab_cols WHERE data_type_owner = ‘XDB’; results in a full table scan of the SYS.COL$ system table! This single clause was responsible for over half the execution time of the dependency query. Hence, the ‘Ignore slow dependencies’ option was born – not querying this and a couple of similar clauses to drastically speed up the dependency query execution time, at the expense of producing incorrect sync scripts in rare edge cases. Needless to say, along with the sync script action ordering, the dependency code in the database registration is one of the most complicated and most rewritten parts of the Schema Compare for Oracle engine. The beta of Schema Compare for Oracle is out now; if you find a bug in it, please do tell us so we can get it fixed!

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• Taming Hopping Windows

  - by Roman Schindlauer

  At first glance, hopping windows seem fairly innocuous and obvious. They organize events into windows with a simple periodic definition: the windows have some duration d (e.g. a window covers 5 second time intervals), an interval or period p (e.g. a new window starts every 2 seconds) and an alignment a (e.g. one of those windows starts at 12:00 PM on March 15, 2012 UTC). var wins = xs     .HoppingWindow(TimeSpan.FromSeconds(5),                    TimeSpan.FromSeconds(2),                    new DateTime(2012, 3, 15, 12, 0, 0, DateTimeKind.Utc)); Logically, there is a window with start time a + np and end time a + np + d for every integer n. That’s a lot of windows. So why doesn’t the following query (always) blow up? var query = wins.Select(win => win.Count()); A few users have asked why StreamInsight doesn’t produce output for empty windows. Primarily it’s because there is an infinite number of empty windows! (Actually, StreamInsight uses DateTimeOffset.MaxValue to approximate “the end of time” and DateTimeOffset.MinValue to approximate “the beginning of time”, so the number of windows is lower in practice.) That was the good news. Now the bad news. Events also have duration. Consider the following simple input: var xs = this.Application                 .DefineEnumerable(() => new[]                     { EdgeEvent.CreateStart(DateTimeOffset.UtcNow, 0) })                 .ToStreamable(AdvanceTimeSettings.IncreasingStartTime); Because the event has no explicit end edge, it lasts until the end of time. So there are lots of non-empty windows if we apply a hopping window to that single event! For this reason, we need to be careful with hopping window queries in StreamInsight. Or we can switch to a custom implementation of hopping windows that doesn’t suffer from this shortcoming. The alternate window implementation produces output only when the input changes. We start by breaking up the timeline into non-overlapping intervals assigned to each window. In figure 1, six hopping windows (“Windows”) are assigned to six intervals (“Assignments”) in the timeline. Next we take input events (“Events”) and alter their lifetimes (“Altered Events”) so that they cover the intervals of the windows they intersect. In figure 1, you can see that the first event e1 intersects windows w1 and w2 so it is adjusted to cover assignments a1 and a2. Finally, we can use snapshot windows (“Snapshots”) to produce output for the hopping windows. Notice however that instead of having six windows generating output, we have only four. The first and second snapshots correspond to the first and second hopping windows. The remaining snapshots however cover two hopping windows each! While in this example we saved only two events, the savings can be more significant when the ratio of event duration to window duration is higher. Figure 1: Timeline The implementation of this strategy is straightforward. We need to set the start times of events to the start time of the interval assigned to the earliest window including the start time. Similarly, we need to modify the end times of events to the end time of the interval assigned to the latest window including the end time. The following snap-to-boundary function that rounds a timestamp value t down to the nearest value t' <= t such that t' is a + np for some integer n will be useful. For convenience, we will represent both DateTime and TimeSpan values using long ticks: static long SnapToBoundary(long t, long a, long p) {     return t - ((t - a) % p) - (t > a ? 0L : p); } How do we find the earliest window including the start time for an event? It’s the window following the last window that does not include the start time assuming that there are no gaps in the windows (i.e. duration < interval), and limitation of this solution. To find the end time of that antecedent window, we need to know the alignment of window ends: long e = a + (d % p); Using the window end alignment, we are finally ready to describe the start time selector: static long AdjustStartTime(long t, long e, long p) {     return SnapToBoundary(t, e, p) + p; } To find the latest window including the end time for an event, we look for the last window start time (non-inclusive): public static long AdjustEndTime(long t, long a, long d, long p) {     return SnapToBoundary(t - 1, a, p) + p + d; } Bringing it together, we can define the translation from events to ‘altered events’ as in Figure 1: public static IQStreamable<T> SnapToWindowIntervals<T>(IQStreamable<T> source, TimeSpan duration, TimeSpan interval, DateTime alignment) {     if (source == null) throw new ArgumentNullException("source");     // reason about DateTime and TimeSpan in ticks     long d = Math.Min(DateTime.MaxValue.Ticks, duration.Ticks);     long p = Math.Min(DateTime.MaxValue.Ticks, Math.Abs(interval.Ticks));     // set alignment to earliest possible window     var a = alignment.ToUniversalTime().Ticks % p;     // verify constraints of this solution     if (d <= 0L) { throw new ArgumentOutOfRangeException("duration"); }     if (p == 0L || p > d) { throw new ArgumentOutOfRangeException("interval"); }     // find the alignment of window ends     long e = a + (d % p);     return source.AlterEventLifetime(         evt => ToDateTime(AdjustStartTime(evt.StartTime.ToUniversalTime().Ticks, e, p)),         evt => ToDateTime(AdjustEndTime(evt.EndTime.ToUniversalTime().Ticks, a, d, p)) -             ToDateTime(AdjustStartTime(evt.StartTime.ToUniversalTime().Ticks, e, p))); } public static DateTime ToDateTime(long ticks) {     // just snap to min or max value rather than under/overflowing     return ticks < DateTime.MinValue.Ticks         ? new DateTime(DateTime.MinValue.Ticks, DateTimeKind.Utc)         : ticks > DateTime.MaxValue.Ticks         ? new DateTime(DateTime.MaxValue.Ticks, DateTimeKind.Utc)         : new DateTime(ticks, DateTimeKind.Utc); } Finally, we can describe our custom hopping window operator: public static IQWindowedStreamable<T> HoppingWindow2<T>(     IQStreamable<T> source,     TimeSpan duration,     TimeSpan interval,     DateTime alignment) {     if (source == null) { throw new ArgumentNullException("source"); }     return SnapToWindowIntervals(source, duration, interval, alignment).SnapshotWindow(); } By switching from HoppingWindow to HoppingWindow2 in the following example, the query returns quickly rather than gobbling resources and ultimately failing! public void Main() {     var start = new DateTimeOffset(new DateTime(2012, 6, 28), TimeSpan.Zero);     var duration = TimeSpan.FromSeconds(5);     var interval = TimeSpan.FromSeconds(2);     var alignment = new DateTime(2012, 3, 15, 12, 0, 0, DateTimeKind.Utc);     var events = this.Application.DefineEnumerable(() => new[]     {         EdgeEvent.CreateStart(start.AddSeconds(0), "e0"),         EdgeEvent.CreateStart(start.AddSeconds(1), "e1"),         EdgeEvent.CreateEnd(start.AddSeconds(1), start.AddSeconds(2), "e1"),         EdgeEvent.CreateStart(start.AddSeconds(3), "e2"),         EdgeEvent.CreateStart(start.AddSeconds(9), "e3"),         EdgeEvent.CreateEnd(start.AddSeconds(3), start.AddSeconds(10), "e2"),         EdgeEvent.CreateEnd(start.AddSeconds(9), start.AddSeconds(10), "e3"),     }).ToStreamable(AdvanceTimeSettings.IncreasingStartTime);     var adjustedEvents = SnapToWindowIntervals(events, duration, interval, alignment);     var query = from win in HoppingWindow2(events, duration, interval, alignment)                 select win.Count();     DisplayResults(adjustedEvents, "Adjusted Events");     DisplayResults(query, "Query"); } As you can see, instead of producing a massive number of windows for the open start edge e0, a single window is emitted from 12:00:15 AM until the end of time: Adjusted Events StartTime EndTime Payload 6/28/2012 12:00:01 AM 12/31/9999 11:59:59 PM e0 6/28/2012 12:00:03 AM 6/28/2012 12:00:07 AM e1 6/28/2012 12:00:05 AM 6/28/2012 12:00:15 AM e2 6/28/2012 12:00:11 AM 6/28/2012 12:00:15 AM e3 Query StartTime EndTime Payload 6/28/2012 12:00:01 AM 6/28/2012 12:00:03 AM 1 6/28/2012 12:00:03 AM 6/28/2012 12:00:05 AM 2 6/28/2012 12:00:05 AM 6/28/2012 12:00:07 AM 3 6/28/2012 12:00:07 AM 6/28/2012 12:00:11 AM 2 6/28/2012 12:00:11 AM 6/28/2012 12:00:15 AM 3 6/28/2012 12:00:15 AM 12/31/9999 11:59:59 PM 1 Regards, The StreamInsight Team

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• Building The Right SharePoint Team For Your Organization

  - by Mark Rackley

  I see the question posted fairly often asking what kind SharePoint team an organization should have. How many people do I need? What roles do I need to fill? What is best for my organization? Well, just like every other answer in SharePoint, the correct answer is “it depends”. Do you ever get sick of hearing that??? I know I do… So, let me give you my thoughts and opinions based upon my experience and what I’ve seen and let you come to your own conclusions. What are the possible SharePoint roles? I guess the first thing you need to understand are the different roles that exist in SharePoint (and their are LOTS). Remember, SharePoint is a massive beast and you will NOT find one person who can do it all. If you are hoping to find that person you will be sorely disappointed. For the most part this is true in SharePoint 2007 and 2010. However, generally things are improved in 2010 and easier for junior individuals to grasp. SharePoint Administrator The absolutely positively only role that you should not be without no matter the size of your organization or SharePoint deployment is a SharePoint administrator. These guys are essential to keeping things running and figuring out what’s wrong when things aren’t running well. These unsung heroes do more before 10 am than I do all day. The bad thing is, when these guys are awesome, you don’t even know they exist because everything is running so smoothly. You should definitely invest some time and money here to make sure you have some competent if not rockstar help. You need an admin who truly loves SharePoint and will go that extra mile when necessary. Let me give you a real world example of what I’m talking about: We have a rockstar admin… and I’m sure she’s sick of my throwing her name around so she’ll just have to live with remaining anonymous in this post… sorry Lori… Anyway! A couple of weeks ago our Server teams came to us and said Hi Lori, I’m finalizing the MOSS servers and doing updates that require a restart; can I restart them? Seems like a harmless request from your server team does it not? Sure, go ahead and apply the patches and reboot during our scheduled maintenance window. No problem? right? Sounded fair to me… but no…. not to our fearless SharePoint admin… I need a complete list of patches that will be applied. There is an update that is out there that will break SharePoint… KB973917 is the patch that has been shown to cause issues. What? You mean Microsoft released a patch that would actually adversely affect SharePoint? If we did NOT have a rockstar admin, our server team would have applied these patches and then when some problem occurred in SharePoint we’d have to go through the fun task of tracking down exactly what caused the issue and resolve it. How much time would that have taken? If you have a junior SharePoint admin or an admin who’s not out there staying on top of what’s going on you could have spent days tracking down something so simple as applying a patch you should not have applied. I will even go as far to say the only SharePoint rockstar you NEED in your organization is a SharePoint admin. You can always outsource really complicated development projects or bring in a rockstar contractor every now and then to make sure you aren’t way off track in other areas. For your day-to-day sanity and to keep SharePoint running smoothly, you need an awesome Admin. Some rockstars in this category are: Ben Curry, Mike Watson, Joel Oleson, Todd Klindt, Shane Young, John Ferringer, Sean McDonough, and of course Lori Gowin. SharePoint Developer Another essential role for your SharePoint deployment is a SharePoint developer. Things do start to get a little hazy here and there are many flavors of “developers”. Are you writing custom code? using SharePoint Designer? What about SharePoint Branding?  Are all of these considered developers? I would say yes. Are they interchangeable? I’d say no. Development in SharePoint is such a large beast in itself. I would say that it’s not so large that you can’t know it all well, but it is so large that there are many people who specialize in one particular category. If you are lucky enough to have someone on staff who knows it all well, you better make sure they are well taken care of because those guys are ready-made to move over to a consulting role and charge you 3 times what you are probably paying them. :) Some of the all-around rockstars are Eric Shupps, Andrew Connell (go Razorbacks), Rob Foster, Paul Schaeflein, and Todd Bleeker SharePoint Power User/No-Code Solutions Developer These SharePoint Swiss Army Knives are essential for quick wins in your organization. These people can twist the out-of-the-box functionality to make it do things you would not even imagine. Give these guys SharePoint Designer, jQuery, InfoPath, and a little time and they will create views, dashboards, and KPI’s that will blow your mind away and give your execs the “wow” they are looking for. Not only can they deliver that wow factor, but they can mashup, merge, and really help make your SharePoint application usable and deliver an overall better user experience. Before you hand off a project to your SharePoint Custom Code developer, let one of these rockstars look at it and show you what they can do (in probably less time). I would say the second most important role you can fill in your organization is one of these guys. Rockstars in this category are Christina Wheeler, Laura Rogers, Jennifer Mason, and Mark Miller SharePoint Developer – Custom Code If you want to really integrate SharePoint into your legacy systems, or really twist it and make it bend to your will, you are going to have to open up Visual Studio and write some custom code.  Remember, SharePoint is essentially just a big, huge, ginormous .NET application, so you CAN write code to make it do ANYTHING, but do you really want to spend the time and effort to do so? At some point with every other form of SharePoint development you are going to run into SOME limitation (SPD Workflows is the big one that comes to mind). If you truly want to knock down all the walls then custom development is the way to go. PLEASE keep in mind when you are looking for a custom code developer that a .NET developer does NOT equal a SharePoint developer. Just SOME of the things these guys write are: Custom Workflows Custom Web Parts Web Service functionality Import data from legacy systems Export data to legacy systems Custom Actions Event Receivers Service Applications (2010) These guys are also the ones generally responsible for packaging everything up into solution packages (you are doing that, right?). Rockstars in this category are Phil Wicklund, Christina Wheeler, Geoff Varosky, and Brian Jackett. SharePoint Branding “But it LOOKS like SharePoint!” Somebody call the WAAAAAAAAAAAAHMbulance…   Themes, Master Pages, Page Layouts, Zones, and over 2000 styles in CSS.. these guys not only have to be comfortable with all of SharePoint’s quirks and pain points when branding, but they have to know it TWICE for publishing and non-publishing sites.  Not only that, but these guys really need to have an eye for graphic design and be able to translate the ramblings of business into something visually stunning. They also have to be comfortable with XSLT, XML, and be able to hand off what they do to your custom developers for them to package as solutions (which you are doing, right?). These rockstars include Heater Waterman, Cathy Dew, and Marcy Kellar SharePoint Architect SharePoint Architects are generally SharePoint Admins or Developers who have moved into more of a BA role? Is that fair to say? These guys really have a grasp and understanding for what SharePoint IS and what it can do. These guys help you structure your farms to meet your needs and help you design your applications the correct way. It’s always a good idea to bring in a rockstar SharePoint Architect to do a sanity check and make sure you aren’t doing anything stupid.  Most organizations probably do not have a rockstar architect on staff. These guys are generally brought in at the deployment of a farm, upgrade of a farm, or for large development projects. I personally also find architects very useful for sitting down with the business to translate their needs into what SharePoint can do. A good architect will be able to pick out what can be done out-of-the-box and what has to be custom built and hand those requirements to the development Staff. Architects can generally fill in as an admin or a developer when needed. Some rockstar architects are Rick Taylor, Dan Usher, Bill English, Spence Harbar, Neil Hodgkins, Eric Harlan, and Bjørn Furuknap. Other Roles / Specialties On top of all these other roles you also get these people who specialize in things like Reporting, BDC (BCS in 2010), Search, Performance, Security, Project Management, etc... etc... etc... Again, most organizations will not have one of these gurus on staff, they’ll just pay out the nose for them when they need them. :) SharePoint End User Everyone else in your organization that touches SharePoint falls into this category. What they actually DO in SharePoint is determined by your governance and what permissions you give these guys. Hopefully you have these guys on a fairly short leash and are NOT giving them access to tools like SharePoint Designer. Sadly end users are the ones who truly make your deployment a success by using it, but are also your biggest enemy in breaking it.  :)  We love you guys… really!!! Okay, all that’s fine and dandy, but what should MY SharePoint team look like? It depends! Okay… Are you just doing out of the box team sites with no custom development? Then you are probably fine with a great Admin team and a great No-Code Solution Development team. How many people do you need? Depends on how busy you can keep them. Sorry, can’t answer the question about numbers without knowing your specific needs. I can just tell you who you MIGHT need and what they will do for you. I’ll leave you with what my ideal SharePoint Team would look like for a particular scenario: Farm / Organization Structure Dev, QA, and 2 Production Farms. 5000 – 10000 Users Custom Development and Integration with legacy systems Team Sites, My Sites, Intranet, Document libraries and overall company collaboration Team Rockstar SharePoint Administrator 2-3 junior SharePoint Administrators SharePoint Architect / Lead Developer 2 Power User / No-Code Solution Developers 2-3 Custom Code developers Branding expert With a team of that size and skill set, they should be able to keep a substantial SharePoint deployment running smoothly and meet your business needs. This does NOT mean that you would not need to bring in contract help from time to time when you need an uber specialist in one area. Also, this team assumes there will be ongoing development for the life of your SharePoint farm. If you are just going to be doing sporadic custom development, it might make sense to partner with an awesome firm that specializes in that sort of work (I can give you the name of a couple if you are interested).  Again though, the size of your team depends on the number of requests you are receiving and how much active deployment you are doing. So, don’t bring in a team that looks like this and then yell at me because they are sitting around with nothing to do or are so overwhelmed that nothing is getting done. I do URGE you to take the proper time to asses your needs and determine what team is BEST for your organization. Also, PLEASE PLEASE PLEASE do not skimp on the talent. When it comes to SharePoint you really do get what you pay for when it comes to employees, contractors, and software.  SharePoint can become absolutely critical to your business and because you skimped on hiring a developer he created a web part that brings down the farm because he doesn’t know what he’s doing, or you hire an admin who thinks it’s fine to stick everything in the same Content Database and then can’t figure out why people are complaining. SharePoint can be an enormous blessing to an organization or it’s biggest curse. Spend the time and money to do it right, or be prepared to spending even more time and money later to fix it.

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• Parsing Concerns

  - by Jesse

  If you’ve ever written an application that accepts date and/or time inputs from an external source (a person, an uploaded file, posted XML, etc.) then you’ve no doubt had to deal with parsing some text representing a date into a data structure that a computer can understand. Similarly, you’ve probably also had to take values from those same data structure and turn them back into their original formats. Most (all?) suitably modern development platforms expose some kind of parsing and formatting functionality for turning text into dates and vice versa. In .NET, the DateTime data structure exposes ‘Parse’ and ‘ToString’ methods for this purpose. This post will focus mostly on parsing, though most of the examples and suggestions below can also be applied to the ToString method. The DateTime.Parse method is pretty permissive in the values that it will accept (though apparently not as permissive as some other languages) which makes it pretty easy to take some text provided by a user and turn it into a proper DateTime instance. Here are some examples (note that the resulting DateTime values are shown using the RFC1123 format): DateTime.Parse("3/12/2010"); //Fri, 12 Mar 2010 00:00:00 GMT DateTime.Parse("2:00 AM"); //Sat, 01 Jan 2011 02:00:00 GMT (took today's date as date portion) DateTime.Parse("5-15/2010"); //Sat, 15 May 2010 00:00:00 GMT DateTime.Parse("7/8"); //Fri, 08 Jul 2011 00:00:00 GMT DateTime.Parse("Thursday, July 1, 2010"); //Thu, 01 Jul 2010 00:00:00 GMT Dealing With Inaccuracy While the DateTime struct has the ability to store a date and time value accurate down to the millisecond, most date strings provided by a user are not going to specify values with that much precision. In each of the above examples, the Parse method was provided a partial value from which to construct a proper DateTime. This means it had to go ahead and assume what you meant and fill in the missing parts of the date and time for you. This is a good thing, especially when we’re talking about taking input from a user. We can’t expect that every person using our software to provide a year, day, month, hour, minute, second, and millisecond every time they need to express a date. That said, it’s important for developers to understand what assumptions the software might be making and plan accordingly. I think the assumptions that were made in each of the above examples were pretty reasonable, though if we dig into this method a little bit deeper we’ll find that there are a lot more assumptions being made under the covers than you might have previously known. One of the biggest assumptions that the DateTime.Parse method has to make relates to the format of the date represented by the provided string. Let’s consider this example input string: ‘10-02-15’. To some people. that might look like ‘15-Feb-2010’. To others, it might be ‘02-Oct-2015’. Like many things, it depends on where you’re from. This Is America! Most cultures around the world have adopted a “little-endian” or “big-endian” formats. (Source: Date And Time Notation By Country) In this context,  a “little-endian” date format would list the date parts with the least significant first while the “big-endian” date format would list them with the most significant first. For example, a “little-endian” date would be “day-month-year” and “big-endian” would be “year-month-day”. It’s worth nothing here that ISO 8601 defines a “big-endian” format as the international standard. While I personally prefer “big-endian” style date formats, I think both styles make sense in that they follow some logical standard with respect to ordering the date parts by their significance. Here in the United States, however, we buck that trend by using what is, in comparison, a completely nonsensical format of “month/day/year”. Almost no other country in the world uses this format. I’ve been fortunate in my life to have done some international travel, so I’ve been aware of this difference for many years, but never really thought much about it. Until recently, I had been developing software for exclusively US-based audiences and remained blissfully ignorant of the different date formats employed by other countries around the world. The web application I work on is being rolled out to users in different countries, so I was recently tasked with updating it to support different date formats. As it turns out, .NET has a great mechanism for dealing with different date formats right out of the box. Supporting date formats for different cultures is actually pretty easy once you understand this mechanism. Pulling the Curtain Back On the Parse Method Have you ever taken a look at the different flavors (read: overloads) that the DateTime.Parse method comes in? In it’s simplest form, it takes a single string parameter and returns the corresponding DateTime value (if it can divine what the date value should be). You can optionally provide two additional parameters to this method: an ‘System.IFormatProvider’ and a ‘System.Globalization.DateTimeStyles’. Both of these optional parameters have some bearing on the assumptions that get made while parsing a date, but for the purposes of this article I’m going to focus on the ‘System.IFormatProvider’ parameter. The IFormatProvider exposes a single method called ‘GetFormat’ that returns an object to be used for determining the proper format for displaying and parsing things like numbers and dates. This interface plays a big role in the globalization capabilities that are built into the .NET Framework. The cornerstone of these globalization capabilities can be found in the ‘System.Globalization.CultureInfo’ class. To put it simply, the CultureInfo class is used to encapsulate information related to things like language, writing system, and date formats for a certain culture. Support for many cultures are “baked in” to the .NET Framework and there is capacity for defining custom cultures if needed (thought I’ve never delved into that). While the details of the CultureInfo class are beyond the scope of this post, so for now let me just point out that the CultureInfo class implements the IFormatInfo interface. This means that a CultureInfo instance created for a given culture can be provided to the DateTime.Parse method in order to tell it what date formats it should expect. So what happens when you don’t provide this value? Let’s crack this method open in Reflector: When no IFormatInfo parameter is provided (i.e. we use the simple DateTime.Parse(string) overload), the ‘DateTimeFormatInfo.CurrentInfo’ is used instead. Drilling down a bit further we can see the implementation of the DateTimeFormatInfo.CurrentInfo property: From this property we can determine that, in the absence of an IFormatProvider being specified, the DateTime.Parse method will assume that the provided date should be treated as if it were in the format defined by the CultureInfo object that is attached to the current thread. The culture specified by the CultureInfo instance on the current thread can vary depending on several factors, but if you’re writing an application where a single instance might be used by people from different cultures (i.e. a web application with an international user base), it’s important to know what this value is. Having a solid strategy for setting the current thread’s culture for each incoming request in an internationally used ASP .NET application is obviously important, and might make a good topic for a future post. For now, let’s think about what the implications of not having the correct culture set on the current thread. Let’s say you’re running an ASP .NET application on a server in the United States. The server was setup by English speakers in the United States, so it’s configured for US English. It exposes a web page where users can enter order data, one piece of which is an anticipated order delivery date. Most users are in the US, and therefore enter dates in a ‘month/day/year’ format. The application is using the DateTime.Parse(string) method to turn the values provided by the user into actual DateTime instances that can be stored in the database. This all works fine, because your users and your server both think of dates in the same way. Now you need to support some users in South America, where a ‘day/month/year’ format is used. The best case scenario at this point is a user will enter March 13, 2011 as ‘25/03/2011’. This would cause the call to DateTime.Parse to blow up since that value doesn’t look like a valid date in the US English culture (Note: In all likelihood you might be using the DateTime.TryParse(string) method here instead, but that method behaves the same way with regard to date formats). “But wait a minute”, you might be saying to yourself, “I thought you said that this was the best case scenario?” This scenario would prevent users from entering orders in the system, which is bad, but it could be worse! What if the order needs to be delivered a day earlier than that, on March 12, 2011? Now the user enters ‘12/03/2011’. Now the call to DateTime.Parse sees what it thinks is a valid date, but there’s just one problem: it’s not the right date. Now this order won’t get delivered until December 3, 2011. In my opinion, that kind of data corruption is a much bigger problem than having the Parse call fail. What To Do? My order entry example is a bit contrived, but I think it serves to illustrate the potential issues with accepting date input from users. There are some approaches you can take to make this easier on you and your users: Eliminate ambiguity by using a graphical date input control. I’m personally a fan of a jQuery UI Datepicker widget. It’s pretty easy to setup, can be themed to match the look and feel of your site, and has support for multiple languages and cultures. Be sure you have a way to track the culture preference of each user in your system. For a web application this could be done using something like a cookie or session state variable. Ensure that the current user’s culture is being applied correctly to DateTime formatting and parsing code. This can be accomplished by ensuring that each request has the handling thread’s CultureInfo set properly, or by using the Format and Parse method overloads that accept an IFormatProvider instance where the provided value is a CultureInfo object constructed using the current user’s culture preference. When in doubt, favor formats that are internationally recognizable. Using the string ‘2010-03-05’ is likely to be recognized as March, 5 2011 by users from most (if not all) cultures. Favor standard date format strings over custom ones. So far we’ve only talked about turning a string into a DateTime, but most of the same “gotchas” apply when doing the opposite. Consider this code: someDateValue.ToString("MM/dd/yyyy"); This will output the same string regardless of what the current thread’s culture is set to (with the exception of some cultures that don’t use the Gregorian calendar system, but that’s another issue all together). For displaying dates to users, it would be better to do this: someDateValue.ToString("d"); This standard format string of “d” will use the “short date format” as defined by the culture attached to the current thread (or provided in the IFormatProvider instance in the proper method overload). This means that it will honor the proper month/day/year, year/month/day, or day/month/year format for the culture. Knowing Your Audience The examples and suggestions shown above can go a long way toward getting an application in shape for dealing with date inputs from users in multiple cultures. There are some instances, however, where taking approaches like these would not be appropriate. In some cases, the provider or consumer of date values that pass through your application are not people, but other applications (or other portions of your own application). For example, if your site has a page that accepts a date as a query string parameter, you’ll probably want to format that date using invariant date format. Otherwise, the same URL could end up evaluating to a different page depending on the user that is viewing it. In addition, if your application exports data for consumption by other systems, it’s best to have an agreed upon format that all systems can use and that will not vary depending upon whether or not the users of the systems on either side prefer a month/day/year or day/month/year format. I’ll look more at some approaches for dealing with these situations in a future post. If you take away one thing from this post, make it an understanding of the importance of knowing where the dates that pass through your system come from and are going to. You will likely want to vary your parsing and formatting approach depending on your audience.

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• asp.net - csharp - jquery - looking for a better and usage solution

  - by LostLord

  hi my dear friends i have a little problem about using jquery...(i reeally do not know jquery but i forced to use it) i am using vs 2008 - asp.net web app with c# also i am using telerik controls in my pages also i am using sqldatasources (Connecting to storedprocedures) in my pages my pages base on master and content pages and in content pages i have mutiviews ================================================================================= in one of the views(inside one of those multiviews)i had made two radcombo boxes for country and city requirement like cascading dropdowns as parent and child combo boxes. i used old way for doing that , i mean i used update panel and in the SelectedIndexChange Event of Parent RadComboBox(Country) i Wrote this code : protected void RadcomboboxCountry_SelectedIndexChanged(object o, RadComboBoxSelectedIndexChangedEventArgs e) { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } my child radcombo box can fill by upper code , let me tell you how : the child sqldatasource have a sp that has a parameter and i fill that parameter by this line - hfSelectedCo_ID.Value = RadcbCoNameInInsert.SelectedValue; RadcbCoNameInInsert.SelectedValue means country ID. after doing that SelectedIndexChange Event of Parent RadComboBox(Country) could not be fire therefore i forced to set the autopostback property to true. afetr doing that every thing was ok until some one told me can u control focus and keydown of your radcombo boxes (when u press enter key on the parent combobox[country] , so child combobox gets focus -- and when u press upperkey on child radcombobox [city], so parent combobox[country] gets focus) (For Users That Do Not Want To Use Mouse for Input Info And Choose items) i told him this is web app , not win form and we can not do that. i googled it and i found jquery the only way for doing that ... so i started using jquery . i wrote this code with jquery for both of them : <script src="../JQuery/jquery-1.4.1.js" language="javascript" type="text/javascript"></script> <script type="text/javascript"> $(function() { $('input[id$=RadcomboboxCountry_Input]').focus(); $('input[id$=RadcomboboxCountry_Input]').select(); $('input[id$=RadcomboboxCountry_Input]').bind('keyup', function(e) { var code = (e.keyCode ? e.keyCode : e.which); if (code == 13) { -----------> Enter Key $('input[id$=RadcomboboxCity_Input]').focus(); $('input[id$=RadcomboboxCity_Input]').select(); } }); $('input[id$=RadcomboboxCity_Input]').bind('keyup', function(e) { var code = (e.keyCode ? e.keyCode : e.which); if (code == 38) { -----------> Upper Key $('input[id$=RadcomboboxCountry_Input]').focus(); $('input[id$=RadcomboboxCountry_Input]').select(); } }); }); </script> this jquery code worked BBBBBBUUUUUUUTTTTTT autopostback=true of the Parent RadComboBox Became A Problem , Because when SelectedIndex Change Of ParentRadComboBox is fired after that Telerik Skins runs and after that i lost parent ComboBox Focus and we should use mouse but we don't want it.... for fix this problem i decided to set autopostback of perentCB to false and convert protected void RadcomboboxCountry_SelectedIndexChanged(object o, RadComboBoxSelectedIndexChangedEventArgs e) { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } to a public non static method without parameters and call it with jquey like this : (i used onclientchanged property of parentcombo box like onclientchanged = "MyMethodForParentCB_InJquery();" insread of selectedindexchange event) public void MyMethodForParentCB_InCodeBehind() { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } for doing that i read the blow manual and do that step by step : ======================================================================= http://www.ajaxprojects.com/ajax/tutorialdetails.php?itemid=732 ======================================================================= but this manual is about static methods and this is my new problem ... when i am using static method like : public static void MyMethodForParentCB_InCodeBehind() { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } so i recieved some errors and this method could not recognize my controls and hidden field... one of those errors like this : Error 2 An object reference is required for the non-static field, method, or property 'Darman.SuperAdmin.Users.hfSelectedCo_ID' C:\Javad\Copy of Darman 6\Darman\SuperAdmin\Users.aspx.cs 231 13 Darman any idea or is there any way to call non static methods with jquery (i know we can not do that but is there another way to solve my problem)???????????????

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• PHP + Code Igniter Timecode Calculation Logic Error

  - by Tim

  Hello everyone, I have what I suspect to be a logic problem with an algorithm I am using to work with Video timecode in PHP. All help is appreciated. The Objective Well basically I want to work with timecode and perform calculations For those not familiar with timecode it looks like this 01:10:58:12 or HH:MM:SS:FF 'AKA' HOURS:MINUTES:SECONDS:FRAMES I have used the script from HERE to help me with working with this format. The Problem Now can i just say that this script works!!! Timecode calculations (in this case additions) are being performed correctly. However this script continually throws the following errors, yet still produces the correct output when I try and do the following calculation 00:01:26:00 + 00:02:00:12 The errors from this calculation are shown below A PHP Error was encountered Severity: Notice Message: Undefined index: key Filename: staff/tools.php Line Number: 169 A PHP Error was encountered Severity: Notice Message: Undefined index: key Filename: staff/tools.php Line Number: 169 Line Number 169 is in the parseInput() function // feed it into the tc array $i=0; foreach ($tc AS $key=>$value) { if ( is_numeric($array["$i"]) ) { $tc["$key"]= $array["$i"]; if ($tc["$key"] < 10 && $tc["$key"] > 0 && strlen($tc['key'])==1 ) $tc["$key"]= "0".$tc["$key"]; } $i++; } return $tc; Now I should also mention that the number of times the above error is thrown depends on what I am calculating 00:00:00:00 + 00:00:00:00 returns no errors. 01:01:01:01 + 02:02:02:02 produces 8 of the above errors. For your reference, here is the code in it's entirety function add_cue_sheet_clips_process() { $sheetID = $_POST['sheet_id']; $clipName = $_POST['clip_name']; $tcIn = $_POST['tc_in']; $tcOut = $_POST['tc_out']; // string $input // returns an associative array of hours, minutes, seconds, and frames // function parseInput ($input) { // timecode should look something like hh:mm:ss;ff // allowed separators are : ; . , // values may be single or double digits // hours are least-significant -- 5.4 == 00:00:05;04 $tc= array("frames"=>"00", "seconds"=>"00", "minutes"=>"00", "hours"=>"00"); $punct= array(":", ";", ".", ","); // too big? too small? $input= trim($input); if (strlen($input)>11 || $input=="") { // invalid input, too long -- bzzt return $tc; } // normalize punctuation $input= str_replace( $punct, ":", $input); // blow it up and reverse it so frames come first $array= explode(":", $input); $array= array_reverse($array); // feed it into the tc array $i=0; foreach ($tc AS $key=>$value) { if ( is_numeric($array["$i"]) ) { $tc["$key"]= $array["$i"]; if ($tc["$key"] < 10 && $tc["$key"] > 0 && strlen($tc['key'])==1 ) $tc["$key"]= "0".$tc["$key"]; } $i++; } return $tc; } // array $tc // returns a float number of seconds // function tcToSec($tc) { $wholeseconds= ($tc['hours']*3600) + ($tc['minutes'] * 60) + ($tc['seconds']); $partseconds= ( $tc['frames'] / 25 ); $seconds= $wholeseconds + $partseconds; return $seconds; } // float $seconds // bool $subtract // returns a timecode array // function secToTc ($seconds=0, $subtract=0) { $tc= array("frames"=>"00", "seconds"=>"00", "minutes"=>"00", "hours"=>"00"); $partseconds= fmod($seconds, 1); $wholeseconds= $seconds - $partseconds; // frames if ($subtract==1) $tc['frames']= floor( $partseconds * 25 ); else $tc['frames']= floor( $partseconds * 25 ); // hours $tc['hours']= floor( $wholeseconds / 3600 ); $minsec= ($wholeseconds - ($tc['hours'] * 3600)); // minutes $tc['minutes']= floor( $minsec / 60 ); // seconds $tc['seconds']= ( $minsec - ($tc['minutes'] * 60) ); // padding foreach ( $tc AS $key=>$value ) { if ($value > 0 && $value < 10) $tc["$key"]= "0".$value; if ($value=="0") $tc["$key"]= "00"; } return $tc; } // array $tc // returns string of well-formed timecode // function tcToString (&$tc) { return $tc['hours'].":".$tc['minutes'].":".$tc['seconds'].";".$tc['frames']; } $timecodeIN = parseInput($tcIn); $timecodeOUT = parseInput($tcOut); // normalized inputs... $tc1 = tcToString($timecodeIN); $tc2 = tcToString($timecodeOUT); // get seconds $seconds1 = tcToSec($timecodeIN); $seconds2 = tcToSec($timecodeOUT); $result = $seconds1 + $seconds2; $timecode3 = secToTc($result, 0); $timecodeDUR = tcToString($timecode3); $clipArray = array('clip_name' => $clipName, 'tc_in' => $tcIn, 'tc_out' => $tcOut, 'tc_duration' => $timecodeDUR); $this->db->insert('tools_cue_sheets_clips', $clipArray); redirect('staff/tools/add_cue_sheet_clips/'.$sheetID); } I hope this is enough information for someone to help me get on top of this, I would be extremely greatful. Thanks, Tim

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• Trouble with copying dictionaries and using deepcopy on an SQLAlchemy ORM object

  - by Az

  Hi there, I'm doing a Simulated Annealing algorithm to optimise a given allocation of students and projects. This is language-agnostic pseudocode from Wikipedia: s ? s0; e ? E(s) // Initial state, energy. sbest ? s; ebest ? e // Initial "best" solution k ? 0 // Energy evaluation count. while k < kmax and e > emax // While time left & not good enough: snew ? neighbour(s) // Pick some neighbour. enew ? E(snew) // Compute its energy. if enew < ebest then // Is this a new best? sbest ? snew; ebest ? enew // Save 'new neighbour' to 'best found'. if P(e, enew, temp(k/kmax)) > random() then // Should we move to it? s ? snew; e ? enew // Yes, change state. k ? k + 1 // One more evaluation done return sbest // Return the best solution found. The following is an adaptation of the technique. My supervisor said the idea is fine in theory. First I pick up some allocation (i.e. an entire dictionary of students and their allocated projects, including the ranks for the projects) from entire set of randomised allocations, copy it and pass it to my function. Let's call this allocation aOld (it is a dictionary). aOld has a weight related to it called wOld. The weighting is described below. The function does the following: Let this allocation, aOld be the best_node From all the students, pick a random number of students and stick in a list Strip (DEALLOCATE) them of their projects ++ reflect the changes for projects (allocated parameter is now False) and lecturers (free up slots if one or more of their projects are no longer allocated) Randomise that list Try assigning (REALLOCATE) everyone in that list projects again Calculate the weight (add up ranks, rank 1 = 1, rank 2 = 2... and no project rank = 101) For this new allocation aNew, if the weight wNew is smaller than the allocation weight wOld I picked up at the beginning, then this is the best_node (as defined by the Simulated Annealing algorithm above). Apply the algorithm to aNew and continue. If wOld < wNew, then apply the algorithm to aOld again and continue. The allocations/data-points are expressed as "nodes" such that a node = (weight, allocation_dict, projects_dict, lecturers_dict) Right now, I can only perform this algorithm once, but I'll need to try for a number N (denoted by kmax in the Wikipedia snippet) and make sure I always have with me, the previous node and the best_node. So that I don't modify my original dictionaries (which I might want to reset to), I've done a shallow copy of the dictionaries. From what I've read in the docs, it seems that it only copies the references and since my dictionaries contain objects, changing the copied dictionary ends up changing the objects anyway. So I tried to use copy.deepcopy().These dictionaries refer to objects that have been mapped with SQLA. Questions: I've been given some solutions to the problems faced but due to my über green-ness with using Python, they all sound rather cryptic to me. Deepcopy isn't playing nicely with SQLA. I've been told thatdeepcopy on ORM objects probably has issues that prevent it from working as you'd expect. Apparently I'd be better off "building copy constructors, i.e. def copy(self): return FooBar(....)." Can someone please explain what that means? I checked and found out that deepcopy has issues because SQLAlchemy places extra information on your objects, i.e. an _sa_instance_state attribute, that I wouldn't want in the copy but is necessary for the object to have. I've been told: "There are ways to manually blow away the old _sa_instance_state and put a new one on the object, but the most straightforward is to make a new object with __init__() and set up the attributes that are significant, instead of doing a full deep copy." What exactly does that mean? Do I create a new, unmapped class similar to the old, mapped one? An alternate solution is that I'd have to "implement __deepcopy__() on your objects and ensure that a new _sa_instance_state is set up, there are functions in sqlalchemy.orm.attributes which can help with that." Once again this is beyond me so could someone kindly explain what it means? A more general question: given the above information are there any suggestions on how I can maintain the information/state for the best_node (which must always persist through my while loop) and the previous_node, if my actual objects (referenced by the dictionaries, therefore the nodes) are changing due to the deallocation/reallocation taking place? That is, without using copy?

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• How should I delete a child object from within a parent's slot? Possibly boost::asio specific.

  - by kaliatech

  I have written a network server class that maintains a std::set of network clients. The network clients emit a signal to the network server on disconnect (via boost::bind). When a network client disconnects, the client instance needs to be removed from the Set and eventually deleted. I would think this is a common pattern, but I am having problems that might, or might not, be specific to ASIO. I've tried to trim down to just the relevant code: /** NetworkServer.hpp **/ class NetworkServices : private boost::noncopyable { public: NetworkServices(void); ~NetworkServices(void); private: void run(); void onNetworkClientEvent(NetworkClientEvent&); private: std::set<boost::shared_ptr<const NetworkClient>> clients; }; /** NetworkClient.cpp **/ void NetworkServices::run() { running = true; boost::asio::io_service::work work(io_service); //keeps service running even if no operations // This creates just one thread for the boost::asio async network services boost::thread iot(boost::bind(&NetworkServices::run_io_service, this)); while (running) { boost::system::error_code err; try { tcp::socket* socket = new tcp::socket(io_service); acceptor->accept(*socket, err); if (!err) { NetworkClient* networkClient = new NetworkClient(io_service, boost::shared_ptr<tcp::socket>(socket)); networkClient->networkClientEventSignal.connect(boost::bind(&NetworkServices::onNetworkClientEvent, this, _1)); clients.insert(boost::shared_ptr<NetworkClient>(networkClient)); networkClient->init(); //kicks off 1st asynch_read call } } // etc... } } void NetworkServices::onNetworkClientEvent(NetworkClientEvent& evt) { switch(evt.getType()) { case NetworkClientEvent::CLIENT_ERROR : { boost::shared_ptr<const NetworkClient> clientPtr = evt.getClient().getSharedPtr(); // ------ THIS IS THE MAGIC LINE ----- // If I keep this, the io_service hangs. If I comment it out, // everything works fine (but I never delete the disconnected NetworkClient). // If actually deleted the client here I might expect problems because it is the caller // of this method via boost::signal and bind. However, The clientPtr is a shared ptr, and a // reference is being kept in the client itself while signaling, so // I would the object is not going to be deleted from the heap here. That seems to be the case. // Never-the-less, this line makes all the difference, most likely because it controls whether or not the NetworkClient ever gets deleted. clients.erase(clientPtr); //I should probably put this socket clean-up in NetworkClient destructor. Regardless by doing this, // I would expect the ASIO socket stuff to be adequately cleaned-up after this. tcp::socket& socket = clientPtr->getSocket(); try { socket.shutdown(boost::asio::socket_base::shutdown_both); socket.close(); } catch(...) { CommServerContext::error("Error while shutting down and closing socket."); } break; } default : { break; } } } /** NetworkClient.hpp **/ class NetworkClient : public boost::enable_shared_from_this<NetworkClient>, Client { NetworkClient(boost::asio::io_service& io_service, boost::shared_ptr<tcp::socket> socket); virtual ~NetworkClient(void); inline boost::shared_ptr<const NetworkClient> getSharedPtr() const { return shared_from_this(); }; boost::signal <void (NetworkClientEvent&)> networkClientEventSignal; void onAsyncReadHeader(const boost::system::error_code& error, size_t bytes_transferred); }; /** NetworkClient.cpp - onAsyncReadHeader method called from io_service.run() thread as result of an async_read operation. Error condition usually result of an unexpected client disconnect.**/ void NetworkClient::onAsyncReadHeader( const boost::system::error_code& error, size_t bytes_transferred) { if (error) { //Make sure this instance doesn't get deleted from parent/slot deferencing //Alternatively, somehow schedule for future delete? boost::shared_ptr<const NetworkClient> clientPtr = getSharedPtr(); //Signal to service that this client is disconnecting NetworkClientEvent evt(*this, NetworkClientEvent::CLIENT_ERROR); networkClientEventSignal(evt); networkClientEventSignal.disconnect_all_slots(); return; } I believe it's not safe to delete the client from within the slot handler because the function return would be ... undefined? (Interestingly, it doesn't seem to blow up on me though.) So I've used boost:shared_ptr along with shared_from_this to make sure the client doesn't get deleted until all slots have been signaled. It doesn't seem to really matter though. I believe this question is not specific to ASIO, but the problem manifests in a peculiar way when using ASIO. I have one thread executing io_service.run(). All ASIO read/write operations are performed asynchronously. Everything works fine with multiple clients connecting/disconnecting UNLESS I delete my client object from the Set per the code above. If I delete my client object, the io_service seemingly deadlocks internally and no further asynchronous operations are performed unless I start another thread. I have try/catches around the io_service.run() call and have not been able to detect any errors. Questions: Are there best practices for deleting child objects, that are also signal emitters, from within parent slots? Any ideas as to why the io_service is hanging when I delete my network client object?

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• Red Gate Coder interviews: Robin Hellen

  - by Michael Williamson

  Robin Hellen is a test engineer here at Red Gate, and is also the latest coder I’ve interviewed. We chatted about debugging code, the roles of software engineers and testers, and why Vala is currently his favourite programming language. How did you get started with programming?It started when I was about six. My dad’s a professional programmer, and he gave me and my sister one of his old computers and taught us a bit about programming. It was an old Amiga 500 with a variant of BASIC. I don’t think I ever successfully completed anything! It was just faffing around. I didn’t really get anywhere with it.But then presumably you did get somewhere with it at some point.At some point. The PC emerged as the dominant platform, and I learnt a bit of Visual Basic. I didn’t really do much, just a couple of quick hacky things. A bit of demo animation. Took me a long time to get anywhere with programming, really.When did you feel like you did start to get somewhere?I think it was when I started doing things for someone else, which was my sister’s final year of university project. She called up my dad two days before she was due to submit, saying “We need something to display a graph!”. Dad says, “I’m too busy, go talk to your brother”. So I hacked up this ugly piece of code, sent it off and they won a prize for that project. Apparently, the graph, the bit that I wrote, was the reason they won a prize! That was when I first felt that I’d actually done something that was worthwhile. That was my first real bit of code, and the ugliest code I’ve ever written. It’s basically an array of pre-drawn line elements that I shifted round the screen to draw a very spikey graph.When did you decide that programming might actually be something that you wanted to do as a career?It’s not really a decision I took, I always wanted to do something with computers. And I had to take a gap year for uni, so I was looking for twelve month internships. I applied to Red Gate, and they gave me a job as a tester. And that’s where I really started having to write code well. To a better standard that I had been up to that point.How did you find coming to Red Gate and working with other coders?I thought it was really nice. I learnt so much just from other people around. I think one of the things that’s really great is that people are just willing to help you learn. Instead of “Don’t you know that, you’re so stupid”, it’s “You can just do it this way”.If you could go back to the very start of that internship, is there something that you would tell yourself?Write shorter code. I have a tendency to write massive, many-thousand line files that I break out of right at the end. And then half-way through a project I’m doing something, I think “Where did I write that bit that does that thing?”, and it’s almost impossible to find. I wrote some horrendous code when I started. Just that principle, just keep things short. Even if looks a bit crazy to be jumping around all over the place all of the time, it’s actually a lot more understandable.And how do you hold yourself to that?Generally, if a function’s going off my screen, it’s probably too long. That’s what I tell myself, and within the team here we have code reviews, so the guys I’m with at the moment are pretty good at pulling me up on, “Doesn’t that look like it’s getting a bit long?”. It’s more just the subjective standard of readability than anything.So you’re an advocate of code review?Yes, definitely. Both to spot errors that you might have made, and to improve your knowledge. The person you’re reviewing will say “Oh, you could have done it that way”. That’s how we learn, by talking to others, and also just sharing knowledge of how your project works around the team, or even outside the team. Definitely a very firm advocate of code reviews.Do you think there’s more we could do with them?I don’t know. We’re struggling with how to add them as part of the process without it becoming too cumbersome. We’ve experimented with a few different ways, and we’ve not found anything that just works.To get more into the nitty gritty: how do you like to debug code?The first thing is to do it in my head. I’ll actually think what piece of code is likely to have caused that error, and take a quick look at it, just to see if there’s anything glaringly obvious there. The next thing I’ll probably do is throw in print statements, or throw some exceptions from various points, just to check: is it going through the code path I expect it to? A last resort is to actually debug code using a debugger.Why is the debugger the last resort?Probably because of the environments I learnt programming in. VB and early BASIC didn’t have much of a debugger, the only way to find out what your program was doing was to add print statements. Also, because a lot of the stuff I tend to work with is non-interactive, if it’s something that takes a long time to run, I can throw in the print statements, set a run off, go and do something else, and look at it again later, rather than trying to remember what happened at that point when I was debugging through it. So it also gives me the record of what happens. I hate just sitting there pressing F5, F5, continually. If you’re having to find out what your code is doing at each line, you’ve probably got a very wrong mental model of what your code’s doing, and you can find that out just as easily by inspecting a couple of values through the print statements.If I were on some codebase that you were also working on, what should I do to make it as easy as possible to understand?I’d say short and well-named methods. The one thing I like to do when I’m looking at code is to find out where a value comes from, and the more layers of indirection there are, particularly DI [dependency injection] frameworks, the harder it is to find out where something’s come from. I really hate that. I want to know if the value come from the user here or is a constant here, and if I can’t find that out, that makes code very hard to understand for me.As a tester, where do you think the split should lie between software engineers and testers?I think the split is less on areas of the code you write and more what you’re designing and creating. The developers put a structure on the code, while my major role is to say which tests we should have, whether we should test that, or it’s not worth testing that because it’s a tiny function in code that nobody’s ever actually going to see. So it’s not a split in the code, it’s a split in what you’re thinking about. Saying what code we should write, but alternatively what code we should take out.In your experience, do the software engineers tend to do much testing themselves?They tend to control the lowest layer of tests. And, depending on how the balance of people is in the team, they might write some of the higher levels of test. Or that might go to the testers. I’m the only tester on my team with three other developers, so they’ll be writing quite a lot of the actual test code, with input from me as to whether we should test that functionality, whereas on other teams, where it’s been more equal numbers, the testers have written pretty much all of the high level tests, just because that’s the best use of resource.If you could shuffle resources around however you liked, do you think that the developers should be writing those high-level tests?I think they should be writing them occasionally. It helps when they have an understanding of how testing code works and possibly what assumptions we’ve made in tests, and they can say “actually, it doesn’t work like that under the hood so you’ve missed this whole area”. It’s one of those agile things that everyone on the team should be at least comfortable doing the various jobs. So if the developers can write test code then I think that’s a very good thing.So you think testers should be able to write production code?Yes, although given most testers skills at coding, I wouldn’t advise it too much! I have written a few things, and I did make a few changes that have actually gone into our production code base. They’re not necessarily running every time but they are there. I think having that mix of skill sets is really useful. In some ways we’re using our own product to test itself, so being able to make those changes where it’s not working saves me a round-trip through the developers. It can be really annoying if the developers have no time to make a change, and I can’t touch the code.If the software engineers are consistently writing tests at all levels, what role do you think the role of a tester is?I think on a team like that, those distinctions aren’t quite so useful. There’ll be two cases. There’s either the case where the developers think they’ve written good tests, but you still need someone with a test engineer mind-set to go through the tests and validate that it’s a useful set, or the correct set for that code. Or they won’t actually be pure developers, they’ll have that mix of test ability in there.I think having slightly more distinct roles is useful. When it starts to blur, then you lose that view of the tests as a whole. The tester job is not to create tests, it’s to validate the quality of the product, and you don’t do that just by writing tests. There’s more things you’ve got to keep in your mind. And I think when you blur the roles, you start to lose that end of the tester.So because you’re working on those features, you lose that holistic view of the whole system?Yeah, and anyone who’s worked on the feature shouldn’t be testing it. You always need to have it tested it by someone who didn’t write it. Otherwise you’re a bit too close and you assume “yes, people will only use it that way”, but the tester will come along and go “how do people use this? How would our most idiotic user use this?”. I might not test that because it might be completely irrelevant. But it’s coming in and trying to have a different set of assumptions.Are you a believer that it should all be automated if possible?Not entirely. So an automated test is always better than a manual test for the long-term, but there’s still nothing that beats a human sitting in front of the application and thinking “What could I do at this point?”. The automated test is very good but they follow that strict path, and they never check anything off the path. The human tester will look at things that they weren’t expecting, whereas the automated test can only ever go “Is that value correct?” in many respects, and it won’t notice that on the other side of the screen you’re showing something completely wrong. And that value might have been checked independently, but you always find a few odd interactions when you’re going through something manually, and you always need to go through something manually to start with anyway, otherwise you won’t know where the important bits to write your automation are.When you’re doing that manual testing, do you think it’s important to do that across the entire product, or just the bits that you’ve touched recently?I think it’s important to do it mostly on the bits you’ve touched, but you can’t ignore the rest of the product. Unless you’re dealing with a very, very self-contained bit, you’re almost always encounter other bits of the product along the way. Most testers I know, even if they are looking at just one path, they’ll keep open and move around a bit anyway, just because they want to find something that’s broken. If we find that your path is right, we’ll go out and hunt something else.How do you think this fits into the idea of continuously deploying, so long as the tests pass?With deploying a website it’s a bit different because you can always pull it back. If you’re deploying an application to customers, when you’ve released it, it’s out there, you can’t pull it back. Someone’s going to keep it, no matter how hard you try there will be a few installations that stay around. So I’d always have at least a human element on that path. With websites, you could probably automate straight out, or at least straight out to an internal environment or a single server in a cloud of fifty that will serve some people. But I don’t think you should release to everyone just on automated tests passing.You’ve already mentioned using BASIC and C# — are there any other languages that you’ve used?I’ve used a few. That’s something that has changed more recently, I’ve become familiar with more languages. Before I started at Red Gate I learnt a bit of C. Then last year, I taught myself Python which I actually really enjoyed using. I’ve also come across another language called Vala, which is sort of a C#-like language. It’s basically a pre-processor for C, but it has very nice syntax. I think that’s currently my favourite language.Any particular reason for trying Vala?I have a completely Linux environment at home, and I’ve been looking for a nice language, and C# just doesn’t cut it because I won’t touch Mono. So, I was looking for something like C# but that was useable in an open source environment, and Vala’s what I found. C#’s got a few features that Vala doesn’t, and Vala’s got a few features where I think “It would be awesome if C# had that”.What are some of the features that it’s missing?Extension methods. And I think that’s the only one that really bugs me. I like to use them when I’m writing C# because it makes some things really easy, especially with libraries that you can’t touch the internals of. It doesn’t have method overloading, which is sometimes annoying.Where it does win over C#?Everything is non-nullable by default, you never have to check that something’s unexpectedly null.Also, Vala has code contracts. This is starting to come in C# 4, but the way it works in Vala is that you specify requirements in short phrases as part of your function signature and they stick to the signature, so that when you inherit it, it has exactly the same code contract as the base one, or when you inherit from an interface, you have to match the signature exactly. Just using those makes you think a bit more about how you’re writing your method, it’s not an afterthought when you’ve got contracts from base classes given to you, you can’t change it. Which I think is a lot nicer than the way C# handles it. When are those actually checked?They’re checked both at compile and run-time. The compile-time checking isn’t very strong yet, it’s quite a new feature in the compiler, and because it compiles down to C, you can write C code and interface with your methods, so you can bypass that compile-time check anyway. So there’s an extra runtime check, and if you violate one of the contracts at runtime, it’s game over for your program, there’s no exception to catch, it’s just goodbye!One thing I dislike about C# is the exceptions. You write a bit of code and fifty exceptions could come from any point in your ten lines, and you can’t mentally model how those exceptions are going to come out, and you can’t even predict them based on the functions you’re calling, because if you’ve accidentally got a derived class there instead of a base class, that can throw a completely different set of exceptions. So I’ve got no way of mentally modelling those, whereas in Vala they’re checked like Java, so you know only these exceptions can come out. You know in advance the error conditions.I think Raymond Chen on Old New Thing says “the only thing you know when you throw an exception is that you’re in an invalid state somewhere in your program, so just kill it and be done with it!”You said you’ve also learnt bits of Python. How did you find that compared to Vala and C#?Very different because of the dynamic typing. I’ve been writing a website for my own use. I’m quite into photography, so I take photos off my camera, post-process them, dump them in a file, and I get a webpage with all my thumbnails. So sort of like Picassa, but written by myself because I wanted something to learn Python with. There are some things that are really nice, I just found it really difficult to cope with the fact that I’m not quite sure what this object type that I’m passed is, I might not ever be sure, so it can randomly blow up on me. But once I train myself to ignore that and just say “well, I’m fairly sure it’s going to be something that looks like this, so I’ll use it like this”, then it’s quite nice.Any particular features that you’ve appreciated?I don’t like any particular feature, it’s just very straightforward to work with. It’s very quick to write something in, particularly as you don’t have to worry that you’ve changed something that affects a different part of the program. If you have, then that part blows up, but I can get this part working right now.If you were doing a big project, would you be willing to do it in Python rather than C# or Vala?I think I might be willing to try something bigger or long term with Python. We’re currently doing an ASP.NET MVC project on C#, and I don’t like the amount of reflection. There’s a lot of magic that pulls values out, and it’s all done under the scenes. It’s almost managed to put a dynamic type system on top of C#, which in many ways destroys the language to me, whereas if you’re already in a dynamic language, having things done dynamically is much more natural. In many ways, you get the worst of both worlds. I think for web projects, I would go with Python again, whereas for anything desktop, command-line or GUI-based, I’d probably go for C# or Vala, depending on what environment I’m in.It’s the fact that you can gain from the strong typing in ways that you can’t so much on the web app. Or, in a web app, you have to use dynamic typing at some point, or you have to write a hell of a lot of boilerplate, and I’d rather use the dynamic typing than write the boilerplate.What do you think separates great programmers from everyone else?Probably design choices. Choosing to write it a piece of code one way or another. For any given program you ask me to write, I could probably do it five thousand ways. A programmer who is capable will see four or five of them, and choose one of the better ones. The excellent programmer will see the largest proportion and manage to pick the best one very quickly without having to think too much about it. I think that’s probably what separates, is the speed at which they can see what’s the best path to write the program in. More Red Gater Coder interviews

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• ASP.NET Frameworks and Raw Throughput Performance

  - by Rick Strahl

  A few days ago I had a curious thought: With all these different technologies that the ASP.NET stack has to offer, what's the most efficient technology overall to return data for a server request? When I started this it was mere curiosity rather than a real practical need or result. Different tools are used for different problems and so performance differences are to be expected. But still I was curious to see how the various technologies performed relative to each just for raw throughput of the request getting to the endpoint and back out to the client with as little processing in the actual endpoint logic as possible (aka Hello World!). I want to clarify that this is merely an informal test for my own curiosity and I'm sharing the results and process here because I thought it was interesting. It's been a long while since I've done any sort of perf testing on ASP.NET, mainly because I've not had extremely heavy load requirements and because overall ASP.NET performs very well even for fairly high loads so that often it's not that critical to test load performance. This post is not meant to make a point  or even come to a conclusion which tech is better, but just to act as a reference to help understand some of the differences in perf and give a starting point to play around with this yourself. I've included the code for this simple project, so you can play with it and maybe add a few additional tests for different things if you like. Source Code on GitHub I looked at this data for these technologies: ASP.NET Web API ASP.NET MVC WebForms ASP.NET WebPages ASMX AJAX Services  (couldn't get AJAX/JSON to run on IIS8 ) WCF Rest Raw ASP.NET HttpHandlers It's quite a mixed bag, of course and the technologies target different types of development. What started out as mere curiosity turned into a bit of a head scratcher as the results were sometimes surprising. What I describe here is more to satisfy my curiosity more than anything and I thought it interesting enough to discuss on the blog :-) First test: Raw Throughput The first thing I did is test raw throughput for the various technologies. This is the least practical test of course since you're unlikely to ever create the equivalent of a 'Hello World' request in a real life application. The idea here is to measure how much time a 'NOP' request takes to return data to the client. So for this request I create the simplest Hello World request that I could come up for each tech. Http Handler The first is the lowest level approach which is an HTTP handler. public class Handler : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; context.Response.Write("Hello World. Time is: " + DateTime.Now.ToString()); } public bool IsReusable { get { return true; } } } WebForms Next I added a couple of ASPX pages - one using CodeBehind and one using only a markup page. The CodeBehind page simple does this in CodeBehind without any markup in the ASPX page: public partial class HelloWorld_CodeBehind : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Response.Write("Hello World. Time is: " + DateTime.Now.ToString() ); Response.End(); } } while the Markup page only contains some static output via an expression:<%@ Page Language="C#" AutoEventWireup="false" CodeBehind="HelloWorld_Markup.aspx.cs" Inherits="AspNetFrameworksPerformance.HelloWorld_Markup" %> Hello World. Time is <%= DateTime.Now %> ASP.NET WebPages WebPages is the freestanding Razor implementation of ASP.NET. Here's the simple HelloWorld.cshtml page:Hello World @DateTime.Now WCF REST WCF REST was the token REST implementation for ASP.NET before WebAPI and the inbetween step from ASP.NET AJAX. I'd like to forget that this technology was ever considered for production use, but I'll include it here. Here's an OperationContract class: [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class WcfService { [OperationContract] [WebGet] public Stream HelloWorld() { var data = Encoding.Unicode.GetBytes("Hello World" + DateTime.Now.ToString()); var ms = new MemoryStream(data); // Add your operation implementation here return ms; } } WCF REST can return arbitrary results by returning a Stream object and a content type. The code above turns the string result into a stream and returns that back to the client. ASP.NET AJAX (ASMX Services) I also wanted to test ASP.NET AJAX services because prior to WebAPI this is probably still the most widely used AJAX technology for the ASP.NET stack today. Unfortunately I was completely unable to get this running on my Windows 8 machine. Visual Studio 2012  removed adding of ASP.NET AJAX services, and when I tried to manually add the service and configure the script handler references it simply did not work - I always got a SOAP response for GET and POST operations. No matter what I tried I always ended up getting XML results even when explicitly adding the ScriptHandler. So, I didn't test this (but the code is there - you might be able to test this on a Windows 7 box). ASP.NET MVC Next up is probably the most popular ASP.NET technology at the moment: MVC. Here's the small controller: public class MvcPerformanceController : Controller { public ActionResult Index() { return View(); } public ActionResult HelloWorldCode() { return new ContentResult() { Content = "Hello World. Time is: " + DateTime.Now.ToString() }; } } ASP.NET WebAPI Next up is WebAPI which looks kind of similar to MVC. Except here I have to use a StringContent result to return the response: public class WebApiPerformanceController : ApiController { [HttpGet] public HttpResponseMessage HelloWorldCode() { return new HttpResponseMessage() { Content = new StringContent("Hello World. Time is: " + DateTime.Now.ToString(), Encoding.UTF8, "text/plain") }; } } Testing Take a minute to think about each of the technologies… and take a guess which you think is most efficient in raw throughput. The fastest should be pretty obvious, but the others - maybe not so much. The testing I did is pretty informal since it was mainly to satisfy my curiosity - here's how I did this: I used Apache Bench (ab.exe) from a full Apache HTTP installation to run and log the test results of hitting the server. ab.exe is a small executable that lets you hit a URL repeatedly and provides counter information about the number of requests, requests per second etc. ab.exe and the batch file are located in the \LoadTests folder of the project. An ab.exe command line  looks like this: ab.exe -n100000 -c20 http://localhost/aspnetperf/api/HelloWorld which hits the specified URL 100,000 times with a load factor of 20 concurrent requests. This results in output like this:   It's a great way to get a quick and dirty performance summary. Run it a few times to make sure there's not a large amount of varience. You might also want to do an IISRESET to clear the Web Server. Just make sure you do a short test run to warm up the server first - otherwise your first run is likely to be skewed downwards. ab.exe also allows you to specify headers and provide POST data and many other things if you want to get a little more fancy. Here all tests are GET requests to keep it simple. I ran each test: 100,000 iterations Load factor of 20 concurrent connections IISReset before starting A short warm up run for API and MVC to make sure startup cost is mitigated Here is the batch file I used for the test: IISRESET REM make sure you add REM C:\Program Files (x86)\Apache Software Foundation\Apache2.2\bin REM to your path so ab.exe can be found REM Warm up ab.exe -n100 -c20 http://localhost/aspnetperf/MvcPerformance/HelloWorldJsonab.exe -n100 -c20 http://localhost/aspnetperf/api/HelloWorldJson ab.exe -n100 -c20 http://localhost/AspNetPerf/WcfService.svc/HelloWorld ab.exe -n100000 -c20 http://localhost/aspnetperf/handler.ashx > handler.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/HelloWorld_CodeBehind.aspx > AspxCodeBehind.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/HelloWorld_Markup.aspx > AspxMarkup.txt ab.exe -n100000 -c20 http://localhost/AspNetPerf/WcfService.svc/HelloWorld > Wcf.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/MvcPerformance/HelloWorldCode > Mvc.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/api/HelloWorld > WebApi.txt I ran each of these tests 3 times and took the average score for Requests/second, with the machine otherwise idle. I did see a bit of variance when running many tests but the values used here are the medians. Part of this has to do with the fact I ran the tests on my local machine - result would probably more consistent running the load test on a separate machine hitting across the network. I ran these tests locally on my laptop which is a Dell XPS with quad core Sandibridge I7-2720QM @ 2.20ghz and a fast SSD drive on Windows 8. CPU load during tests ran to about 70% max across all 4 cores (IOW, it wasn't overloading the machine). Ideally you can try running these tests on a separate machine hitting the local machine. If I remember correctly IIS 7 and 8 on client OSs don't throttle so the performance here should be Results Ok, let's cut straight to the chase. Below are the results from the tests… It's not surprising that the handler was fastest. But it was a bit surprising to me that the next fastest was WebForms and especially Web Forms with markup over a CodeBehind page. WebPages also fared fairly well. MVC and WebAPI are a little slower and the slowest by far is WCF REST (which again I find surprising). As mentioned at the start the raw throughput tests are not overly practical as they don't test scripting performance for the HTML generation engines or serialization performances of the data engines. All it really does is give you an idea of the raw throughput for the technology from time of request to reaching the endpoint and returning minimal text data back to the client which indicates full round trip performance. But it's still interesting to see that Web Forms performs better in throughput than either MVC, WebAPI or WebPages. It'd be interesting to try this with a few pages that actually have some parsing logic on it, but that's beyond the scope of this throughput test. But what's also amazing about this test is the sheer amount of traffic that a laptop computer is handling. Even the slowest tech managed 5700 requests a second, which is one hell of a lot of requests if you extrapolate that out over a 24 hour period. Remember these are not static pages, but dynamic requests that are being served. Another test - JSON Data Service Results The second test I used a JSON result from several of the technologies. I didn't bother running WebForms and WebPages through this test since that doesn't make a ton of sense to return data from the them (OTOH, returning text from the APIs didn't make a ton of sense either :-) In these tests I have a small Person class that gets serialized and then returned to the client. The Person class looks like this: public class Person { public Person() { Id = 10; Name = "Rick"; Entered = DateTime.Now; } public int Id { get; set; } public string Name { get; set; } public DateTime Entered { get; set; } } Here are the updated handler classes that use Person: Handler public class Handler : IHttpHandler { public void ProcessRequest(HttpContext context) { var action = context.Request.QueryString["action"]; if (action == "json") JsonRequest(context); else TextRequest(context); } public void TextRequest(HttpContext context) { context.Response.ContentType = "text/plain"; context.Response.Write("Hello World. Time is: " + DateTime.Now.ToString()); } public void JsonRequest(HttpContext context) { var json = JsonConvert.SerializeObject(new Person(), Formatting.None); context.Response.ContentType = "application/json"; context.Response.Write(json); } public bool IsReusable { get { return true; } } } This code adds a little logic to check for a action query string and route the request to an optional JSON result method. To generate JSON, I'm using the same JSON.NET serializer (JsonConvert.SerializeObject) used in Web API to create the JSON response. WCF REST   [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class WcfService { [OperationContract] [WebGet] public Stream HelloWorld() { var data = Encoding.Unicode.GetBytes("Hello World " + DateTime.Now.ToString()); var ms = new MemoryStream(data); // Add your operation implementation here return ms; } [OperationContract] [WebGet(ResponseFormat=WebMessageFormat.Json,BodyStyle=WebMessageBodyStyle.WrappedRequest)] public Person HelloWorldJson() { // Add your operation implementation here return new Person(); } } For WCF REST all I have to do is add a method with the Person result type.   ASP.NET MVC public class MvcPerformanceController : Controller { // // GET: /MvcPerformance/ public ActionResult Index() { return View(); } public ActionResult HelloWorldCode() { return new ContentResult() { Content = "Hello World. Time is: " + DateTime.Now.ToString() }; } public JsonResult HelloWorldJson() { return Json(new Person(), JsonRequestBehavior.AllowGet); } } For MVC all I have to do for a JSON response is return a JSON result. ASP.NET internally uses JavaScriptSerializer. ASP.NET WebAPI public class WebApiPerformanceController : ApiController { [HttpGet] public HttpResponseMessage HelloWorldCode() { return new HttpResponseMessage() { Content = new StringContent("Hello World. Time is: " + DateTime.Now.ToString(), Encoding.UTF8, "text/plain") }; } [HttpGet] public Person HelloWorldJson() { return new Person(); } [HttpGet] public HttpResponseMessage HelloWorldJson2() { var response = new HttpResponseMessage(HttpStatusCode.OK); response.Content = new ObjectContent<Person>(new Person(), GlobalConfiguration.Configuration.Formatters.JsonFormatter); return response; } } Testing and Results To run these data requests I used the following ab.exe commands:REM JSON RESPONSES ab.exe -n100000 -c20 http://localhost/aspnetperf/Handler.ashx?action=json > HandlerJson.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/MvcPerformance/HelloWorldJson > MvcJson.txt ab.exe -n100000 -c20 http://localhost/aspnetperf/api/HelloWorldJson > WebApiJson.txt ab.exe -n100000 -c20 http://localhost/AspNetPerf/WcfService.svc/HelloWorldJson > WcfJson.txt The results from this test run are a bit interesting in that the WebAPI test improved performance significantly over returning plain string content. Here are the results:   The performance for each technology drops a little bit except for WebAPI which is up quite a bit! From this test it appears that WebAPI is actually significantly better performing returning a JSON response, rather than a plain string response. Snag with Apache Benchmark and 'Length Failures' I ran into a little snag with Apache Benchmark, which was reporting failures for my Web API requests when serializing. As the graph shows performance improved significantly from with JSON results from 5580 to 6530 or so which is a 15% improvement (while all others slowed down by 3-8%). However, I was skeptical at first because the WebAPI test reports showed a bunch of errors on about 10% of the requests. Check out this report: Notice the Failed Request count. What the hey? Is WebAPI failing on roughly 10% of requests when sending JSON? Turns out: No it's not! But it took some sleuthing to figure out why it reports these failures. At first I thought that Web API was failing, and so to make sure I re-ran the test with Fiddler attached and runiisning the ab.exe test by using the -X switch: ab.exe -n100 -c10 -X localhost:8888 http://localhost/aspnetperf/api/HelloWorldJson which showed that indeed all requests where returning proper HTTP 200 results with full content. However ab.exe was reporting the errors. After some closer inspection it turned out that the dates varying in size altered the response length in dynamic output. For example: these two results: {"Id":10,"Name":"Rick","Entered":"2012-09-04T10:57:24.841926-10:00"} {"Id":10,"Name":"Rick","Entered":"2012-09-04T10:57:24.8519262-10:00"} are different in length for the number which results in 68 and 69 bytes respectively. The same URL produces different result lengths which is what ab.exe reports. I didn't notice at first bit the same is happening when running the ASHX handler with JSON.NET result since it uses the same serializer that varies the milliseconds. Moral: You can typically ignore Length failures in Apache Benchmark and when in doubt check the actual output with Fiddler. Note that the other failure values are accurate though. Another interesting Side Note: Perf drops over Time As I was running these tests repeatedly I was finding that performance steadily dropped from a startup peak to a 10-15% lower stable level. IOW, with Web API I'd start out with around 6500 req/sec and in subsequent runs it keeps dropping until it would stabalize somewhere around 5900 req/sec occasionally jumping lower. For these tests this is why I did the IIS RESET and warm up for individual tests. This is a little puzzling. Looking at Process Monitor while the test are running memory very quickly levels out as do handles and threads, on the first test run. Subsequent runs everything stays stable, but the performance starts going downwards. This applies to all the technologies - Handlers, Web Forms, MVC, Web API - curious to see if others test this and see similar results. Doing an IISRESET then resets everything and performance starts off at peak again… Summary As I stated at the outset, these were informal to satiate my curiosity not to prove that any technology is better or even faster than another. While there clearly are differences in performance the differences (other than WCF REST which was by far the slowest and the raw handler which was by far the highest) are relatively minor, so there is no need to feel that any one technology is a runaway standout in raw performance. Choosing a technology is about more than pure performance but also about the adequateness for the job and the easy of implementation. The strengths of each technology will make for any minor performance difference we see in these tests. However, to me it's important to get an occasional reality check and compare where new technologies are heading. Often times old stuff that's been optimized and designed for a time of less horse power can utterly blow the doors off newer tech and simple checks like this let you compare. Luckily we're seeing that much of the new stuff performs well even in V1.0 which is great. To me it was very interesting to see Web API perform relatively badly with plain string content, which originally led me to think that Web API might not be properly optimized just yet. For those that caught my Tweets late last week regarding WebAPI's slow responses was with String content which is in fact considerably slower. Luckily where it counts with serialized JSON and XML WebAPI actually performs better. But I do wonder what would make generic string content slower than serialized code? This stresses another point: Don't take a single test as the final gospel and don't extrapolate out from a single set of tests. Certainly Twitter can make you feel like a fool when you post something immediate that hasn't been fleshed out a little more <blush>. Egg on my face. As a result I ended up screwing around with this for a few hours today to compare different scenarios. Well worth the time… I hope you found this useful, if not for the results, maybe for the process of quickly testing a few requests for performance and charting out a comparison. Now onwards with more serious stuff… Resources Source Code on GitHub Apache HTTP Server Project (ab.exe is part of the binary distribution)© Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET  Web Api   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Dynamically loading Assemblies to reduce Runtime Depencies

  - by Rick Strahl

  I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change.  So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. That being said though - I serialized 10,000 objects in 80ms vs. 45ms so this isn't hardly slouchy. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?On occasion dynamic loading makes sense. But there's a price to be paid in added code complexity and a performance hit. But for some operations that are not pivotal to a component or application and only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful tool. Hopefully some of you find this information useful…© Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET  C#   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Dynamically loading Assemblies to reduce Runtime Dependencies

  - by Rick Strahl

  I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change.  So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. This will change though depending on the size of objects serialized - the larger the object the more processing time is spent inside the actual dynamically activated components and the less difference there will be. Dynamic code is always slower, but how much it really affects your application primarily depends on how frequently the dynamic code is called in relation to the non-dynamic code executing. In most situations where dynamic code is used 'to get the process rolling' as I do here the overhead is small enough to not matter.All that being said though - I serialized 10,000 objects in 80ms vs. 45ms so this is hardly slouchy performance. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?Dynamic loading is not something you need to worry about but on occasion dynamic loading makes sense. But there's a price to be paid in added code  and a performance hit which depends on how frequently the dynamic code is accessed. But for some operations that are not pivotal to a component or application and are only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files adding dependencies and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems like a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful option in your toolset… © Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET  C#   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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