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• Oracle TimesTen In-Memory Database Performance on SPARC T4-2

  - by Brian

  The Oracle TimesTen In-Memory Database is optimized to run on Oracle's SPARC T4 processor platforms running Oracle Solaris 11 providing unsurpassed scalability, performance, upgradability, protection of investment and return on investment. The following demonstrate the value of combining Oracle TimesTen In-Memory Database with SPARC T4 servers and Oracle Solaris 11: On a Mobile Call Processing test, the 2-socket SPARC T4-2 server outperforms: Oracle's SPARC Enterprise M4000 server (4 x 2.66 GHz SPARC64 VII+) by 34%. Oracle's SPARC T3-4 (4 x 1.65 GHz SPARC T3) by 2.7x, or 5.4x per processor. Utilizing the TimesTen Performance Throughput Benchmark (TPTBM), the SPARC T4-2 server protects investments with: 2.1x the overall performance of a 4-socket SPARC Enterprise M4000 server in read-only mode and 1.5x the performance in update-only testing. This is 4.2x more performance per processor than the SPARC64 VII+ 2.66 GHz based system. 10x more performance per processor than the SPARC T2+ 1.4 GHz server. 1.6x better performance per processor than the SPARC T3 1.65 GHz based server. In replication testing, the two socket SPARC T4-2 server is over 3x faster than the performance of a four socket SPARC Enterprise T5440 server in both asynchronous replication environment and the highly available 2-Safe replication. This testing emphasizes parallel replication between systems. Performance Landscape Mobile Call Processing Test Performance System Processor Sockets/Cores/Threads Tps SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 218,400 M4000 SPARC64 VII+, 2.66 GHz 4 16 32 162,900 SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 80,400 TimesTen Performance Throughput Benchmark (TPTBM) Read-Only System Processor Sockets/Cores/Threads Tps SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 7.9M SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 6.5M M4000 SPARC64 VII+, 2.66 GHz 4 16 32 3.1M T5440 SPARC T2+, 1.4 GHz 4 32 256 3.1M TimesTen Performance Throughput Benchmark (TPTBM) Update-Only System Processor Sockets/Cores/Threads Tps SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 547,800 M4000 SPARC64 VII+, 2.66 GHz 4 16 32 363,800 SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 240,500 TimesTen Replication Tests System Processor Sockets/Cores/Threads Asynchronous 2-Safe SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 38,024 13,701 SPARC T5440 SPARC T2+, 1.4 GHz 4 32 256 11,621 4,615 Configuration Summary Hardware Configurations: SPARC T4-2 server 2 x SPARC T4 processors, 2.85 GHz 256 GB memory 1 x 8 Gbs FC Qlogic HBA 1 x 6 Gbs SAS HBA 4 x 300 GB internal disks Sun Storage F5100 Flash Array (40 x 24 GB flash modules) 1 x Sun Fire X4275 server configured as COMSTAR head SPARC T3-4 server 4 x SPARC T3 processors, 1.6 GHz 512 GB memory 1 x 8 Gbs FC Qlogic HBA 8 x 146 GB internal disks 1 x Sun Fire X4275 server configured as COMSTAR head SPARC Enterprise M4000 server 4 x SPARC64 VII+ processors, 2.66 GHz 128 GB memory 1 x 8 Gbs FC Qlogic HBA 1 x 6 Gbs SAS HBA 2 x 146 GB internal disks Sun Storage F5100 Flash Array (40 x 24 GB flash modules) 1 x Sun Fire X4275 server configured as COMSTAR head Software Configuration: Oracle Solaris 11 11/11 Oracle TimesTen 11.2.2.4 Benchmark Descriptions TimesTen Performance Throughput BenchMark (TPTBM) is shipped with TimesTen and measures the total throughput of the system. The workload can test read-only, update-only, delete and insert operations as required. Mobile Call Processing is a customer-based workload for processing calls made by mobile phone subscribers. The workload has a mixture of read-only, update, and insert-only transactions. The peak throughput performance is measured from multiple concurrent processes executing the transactions until a peak performance is reached via saturation of the available resources. Parallel Replication tests using both asynchronous and 2-Safe replication methods. For asynchronous replication, transactions are processed in batches to maximize the throughput capabilities of the replication server and network. In 2-Safe replication, also known as no data-loss or high availability, transactions are replicated between servers immediately emphasizing low latency. For both environments, performance is measured in the number of parallel replication servers and the maximum transactions-per-second for all concurrent processes. See Also SPARC T4-2 Server oracle.com OTN Oracle TimesTen In-Memory Database oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 1 October 2012.

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• concurrency::accelerator_view

  - by Daniel Moth

  Overview We saw previously that accelerator represents a target for our C++ AMP computation or memory allocation and that there is a notion of a default accelerator. We ended that post by introducing how one can obtain accelerator_view objects from an accelerator object through the accelerator class's default_view property and the create_view method. The accelerator_view objects can be thought of as handles to an accelerator. You can also construct an accelerator_view given another accelerator_view (through the copy constructor or the assignment operator overload). Speaking of operator overloading, you can also compare (for equality and inequality) two accelerator_view objects between them to determine if they refer to the same underlying accelerator. We'll see later that when we use concurrency::array objects, the allocation of data takes place on an accelerator at array construction time, so there is a constructor overload that accepts an accelerator_view object. We'll also see later that a new concurrency::parallel_for_each function overload can take an accelerator_view object, so it knows on what target to execute the computation (represented by a lambda that the parallel_for_each also accepts). Beyond normal usage, accelerator_view is a quality of service concept that offers isolation to multiple "consumers" of an accelerator. If in your code you are accessing the accelerator from multiple threads (or, in general, from different parts of your app), then you'll want to create separate accelerator_view objects for each thread. flush, wait, and queuing_mode When you create an accelerator_view via the create_view method of the accelerator, you pass in an option of immediate or deferred, which are the two members of the queuing_mode enum. At any point you can access this value from the queuing_mode property of the accelerator_view. When the queuing_mode value is immediate (which is the default), any commands sent to the device such as kernel invocations and data transfers (e.g. parallel_for_each and copy, as we'll see in future posts), will get submitted as soon as the runtime sees fit (that is the definition of immediate). When the value of queuing_mode is deferred, the commands will be batched up. To send all buffered commands to the device for execution, there is a non-blocking flush method that you can call. If you wish to block until all the commands have been sent, there is a wait method you can call. Deferring is a more advanced scenario aimed at performance gains when you are submitting many device commands and you want to avoid the tiny overhead of flushing/submitting each command separately. Querying information Just like accelerator, accelerator_view exposes the is_debug and version properties. In fact, you can always access the accelerator object from the accelerator property on the accelerator_view class to access the accelerator interface we looked at previously. Interop with D3D (aka DX) In a later post I'll show an example of an app that uses C++ AMP to compute data that is used in pixel shaders. In those scenarios, you can benefit by integrating C++ AMP into your graphics pipeline and one of the building blocks for that is being able to use the same device context from both the compute kernel and the other shaders. You can do that by going from accelerator_view to device context (and vice versa), through part of our interop API in amp.h: *get_device, create_accelerator_view. More on those in a later post. Comments about this post by Daniel Moth welcome at the original blog.

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• What Did You Do? is a Bad Question

  - by Ajarn Mark Caldwell

  Brian Moran (blog | Twitter) did a great presentation today for the PASS Professional Development Virtual Chapter on The Art of Questions.  One of the points that Brian made was that there are good questions and bad (or at least not-as-good) questions.  Good questions tend to open-up the conversation and engender positive reactions (perhaps even trust and respect) between the participants; and bad questions tend to close-down a conversation either through the narrow list of possible responses (e.g. strictly Yes/No) or through the negative reactions they can produce.  And this explains why I so frequently had problems troubleshooting real-time problems with users in the past.  I’ll explain that in more detail below, but before we go on, let me recommend that you watch the recording of Brian’s presentation to learn why the question Why is often problematic in the U.S. and yet we so often resort to it. For a short portion (3 years) of my career, I taught basic computer skills and Office applications in an adult vocational school, and this gave me ample opportunity to do live troubleshooting of user challenges with computers.  And like many people who ended up in computer related jobs, I also have had numerous times where I was called upon by less computer-savvy individuals to help them with some challenge they were having, whether it was part of my job or not.  One of the things that I noticed, especially during my time as a teacher, was that when I was helping somebody, typically the first question I would ask them was, “What did you do?”  This seemed to me like a good way to start my detective work trying to figure out what happened, what went wrong, how to fix it, and how to help the person avoid it again in the future.  I always asked it in a polite tone of voice as I was just trying to gather the facts before diving in deeper.  However; 99.999% of the time, I always got the same answer, “Nothing!”  For a long time this frustrated me because (remember I’m in detective mode at that point) I knew it could not possibly be true.  They HAD to have done SOMETHING…just tell me what were the last actions you took before this problem presented itself.  But no, they always stuck with “Nothing”.  At which point, with frustration growing, and not a little bit of disdain for their lack of helpfulness, I would usually ask them to move aside while I took over their machine and got them out of whatever they had gotten themselves into.  After a while I just grew used to the fact that this was the answer I would usually receive, but I always kept asking because for the .001% of the people who would actually tell me, I could then help them understand what went wrong and how to avoid it in the future. Now, after hearing Brian’s talk, I understand what the problem was.  Even though I meant to just be in an information gathering mode, the words I was using, “What did YOU do?” have such a strong negative connotation that people would instinctively go into defense-mode and stop sharing information that might make them look bad.  Many of them probably were not even consciously aware that they had gone on the defensive, but the self-preservation instinct, especially self-preservation of the ego, is so strong that people would end up there without even realizing it. So, if “What did you do” is a bad question, what would have been better?  Well, one suggestion that Brian makes in his talk is something along the lines of, “Can you tell me what led up to this?” or “what was happening on the computer right before this came up?”  It’s subtle, but the point is to take the focus off of the person and their behavior; instead depersonalizing it and talk about events from more of a 3rd-party observer point of view.  With this approach, people will be more likely to talk about what the computer did and what they did in response to it without feeling the interrogation spotlight is on them.  They are also more likely to mention other events that occurred around the same time that may or may not be related, but which could certainly help you troubleshoot a larger problem if it is not just user actions.  And that is the ultimate goal of your asking the questions.  So yes, it does matter how you ask the question; and there are such things as good questions and bad questions.  Excellent topic Brian!  Thanks for getting the thinking gears churning! (Cross-posted to the Professional Development Virtual Chapter blog.)

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• glsl shader to allow color change of skydome ogre3d

  - by Tim

  I'm still very new to all this but learning a lot. I'm putting together an application using Ogre3d as the rendering engine. So far I've got it running, with a simple scene, a day/night cycle system which is working okay. I'm now moving on to looking at changing the color of the skydome material based on the time of day. What I've done so far is to create a struct to hold the ColourValues for the different aspects of the scene. struct todColors { Ogre::ColourValue sky; Ogre::ColourValue ambient; Ogre::ColourValue sun; }; I created an array to store all the colours todColors sceneColours [4]; I populated the array with the colours I want to use for the various times of the day. For instance DayTime (when the sun is high in the sky) sceneColours[2].sky = Ogre::ColourValue(135/255, 206/255, 235/255, 255); sceneColours[2].ambient = Ogre::ColourValue(135/255, 206/255, 235/255, 255); sceneColours[2].sun = Ogre::ColourValue(135/255, 206/255, 235/255, 255); I've got code to work out the time of the day using a float currentHours to store the current hour of the day 10.5 = 10:30 am. This updates constantly and updates the sun as required. I am then calculating the appropriate colours for the time of day when relevant using else if( currentHour >= 4 && currentHour < 7) { // Lerp from night to morning Ogre::ColourValue lerp = Ogre::Math::lerp<Ogre::ColourValue, float>(sceneColours[GT_TOD_NIGHT].sky , sceneColours[GT_TOD_MORNING].sky, (currentHour - 4) / (7 - 4)); } My original attempt to get this to work was to dynamically generate a material with the new colour and apply that material to the skydome. This, as you can probably guess... didn't go well. I know it's possible to use shaders where you can pass information such as colour to the shader from the code but I am unsure if there is an existing simple shader to change a colour like this or if I need to create one. What is involved in creating a shader and material definition that would allow me to change the colour of a material without the overheads of dynamically generating materials all the time? EDIT : I've created a glsl vertex and fragment shaders as follows. Vertex uniform vec4 newColor; void main() { gl_FrontColor = newColor; gl_Position = ftransform(); } Fragment void main() { gl_FragColor = gl_Color; } I can pass a colour to it using ShaderDesigner and it seems to work. I now need to investigate how to use it within Ogre as a material. EDIT : I created a material file like this : vertex_program colour_vs_test glsl { source test.vert default_params { param_named newColor float4 0.0 0.0 0.0 1 } } fragment_program colour_fs_glsl glsl { source test.frag } material Test/SkyColor { technique { pass { lighting off fragment_program_ref colour_fs_glsl { } vertex_program_ref colour_vs_test { } } } } In the code I have tried : Ogre::MaterialPtr material = Ogre::MaterialManager::getSingleton().getByName("Test/SkyColor"); Ogre::GpuProgramParametersSharedPtr params = material->getTechnique(0)->getPass(0)->getVertexProgramParameters(); params->setNamedConstant("newcolor", Ogre::Vector4(0.7, 0.5, 0.3, 1)); I've set that as the Skydome material which seems to work initially. I am doing the same with the code that is attempting to lerp between colours, but when I include it there, it all goes black. Seems like there is now a problem with my colour lerping.

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• Filtering data in LINQ with the help of where clause

  - by vik20000in

   LINQ has bought with itself a super power of querying Objects, Database, XML, SharePoint and nearly any other data structure. The power of LINQ lies in the fact that it is managed code that lets you write SQL type code to fetch data.  Whenever working with data we always need a way to filter out the data based on different condition. In this post we will look at some of the different ways in which we can filter data in LINQ with the help of where clause. Simple Filter for an array. Let’s say we have an array of number and we want to filter out data based on some condition. Below is an example int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; var lowNums =                 from num in numbers                 where num < 5                 select num;   Filter based on one of the property in the class. With the help of LINQ we can also filer out data from a list based on value of some property. var soldOutProducts =                 from prod in products                 where prod.UnitsInStock == 0                 select prod; Filter based on Multiple of the property in the class. var expensiveInStockProducts =         from prod in products         where prod.UnitsInStock > 0 && prod.UnitPrice > 3.00M         select prod; Filter based on the index of the Item in the list.In the below example we can see that we are able to filter data based on the index of the item in the list. string[] digits = { "zero", "one", "two", "three", "four", "five", "six"}; var shortDigits = digits.Where((digit, index) => digit.Length < index); There are many other way in which we can filter out data in LINQ. In the above post I have tried and shown few ways using the LINQ. Vikram

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• Using the RSSBus Salesforce Excel Add-In From Excel Macros (VBA)

  - by dataintegration

  The RSSBus Salesforce Excel Add-In makes it easy to retrieve and update data from Salesforce from within Microsoft Excel. In addition to the built-in wizards that make data manipulation possible without code, the full functionality of the RSSBus Excel Add-Ins is available programmatically with Excel Macros (VBA) and Excel Functions. This article shows how to write an Excel macro that can be used to perform bulk inserts into Salesforce. Although this article uses the Salesforce Excel Add-In as an example, the same process can be applied to any of the Excel Add-Ins available on our website. Step 1: Download and install the RSSBus Excel Add-In available on our website. Step 2: Open Excel and create place holder cells for the connection details that are needed from the macro. In this article, a spreadsheet will be created for batch inserts, and these cells will store the connection details, and will be used to report the job Id, the batch Id, and the batch status. Step 3: Switch to the Developer tab in Excel. Add a new button on the spreadsheet, and create a new macro associated with it. This macro will contain the code needed to insert a batch of rows into Salesforce. Step 4: Add a reference to the Excel Add-In by selecting Tools --> References --> RSSBus Excel Add-In. The macro functions of the Excel Add-In will be available once the reference has been added. The following code shows how to call a Stored Procedure. In this example, a job is created to insert Leads by calling the CreateJob stored procedure. CreateJob returns a jobId that can be used to upload a large number of Leads in one transaction. Note the use of cells B1, B2, B3, and B4 that were created in Step 2 to read the connection settings from the Excel SpreadSheet and to write out the status of the procedure. methodName = "CreateJob" module.SetProviderName ("Salesforce") nameArray = Array("ObjectName", "Action", "ConcurrencyMode") valueArray = Array("Lead", "insert", "Serial") user = Range("B1").value pass = Range("B2").value atoken = Range("B3").value If (Not user = "" And Not pass = "" And Not atoken = "") Then module.SetConnectionString ("User=" + user + ";Password=" + pass + ";Access Token=" + atoken + ";") If module.CallSP(methodName, nameArray, valueArray) Then Dim ColumnCount As Integer ColumnCount = module.GetColumnCount Dim idIndex As Integer For Count = 0 To ColumnCount - 1 Dim colName As String colName = module.GetColumnName(Count) If module.GetColumnName(Count) = "id" Then idIndex = Count End If Next While (Not module.EOF) Range("B4").value = module.GetValue(idIndex) module.MoveNext Wend Else MsgBox "The CreateJob query failed." End If Exit Sub Else MsgBox "Please specify the connection details." Exit Sub End If Error: MsgBox "ERROR: " & Err.Description Step 5: Add the code to your macro. If you use the code above, you can check the results at Salesforce.com. They can be seen at Administration Setup -> Monitoring -> Bulk Data Load Jobs. Download the attached sample file for a more complete demo. Distributing an Excel File With Macros An Excel file with macros is saved using the .xlms extension. The code for the macro remains in the Excel file, and you can distribute your Excel file to any machine where the RSSBus Salesforce Excel Add-In is already installed. Macro Sample File Please download the fully functional sample excel file that includes the code referenced here. You will also need the RSSBus Excel Add-In to make the connection. You can download a free trial here. Note: You may get an error message stating: "Can't find project or library." in Excel 2007, since this example is made using Excel 2010. To resolve this, navigate to Tools -> References and uncheck the "MISSING: RSSBus Excel Add-In", then scroll down and check the "RSSBus Excel Add-In" listed below it.

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• 30 Steps to Master ASP.NET MVC Application development

  - by Rajesh Pillai

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Welcome Readers!,   I am starting out a new series on ASP.NET  MVC skill building which will be posted over the next couple of weeks.  Let me know your thoughts on the content, which I have planned and a couple of them has been taken from ASP.NET MVC2 Cookbook. (NOTE: Only the heading has been taken, the content will be not :)).   Do let me know what you would like to see, or any additional inputs or ideas to cover in this topics.  The 30 steps are oultined below for quick reference.  Will start filling this out quickly.   Outlined is the ‘30’ step to master ASP.NET MVC.   A Peek Into Model What is a model? Different types of model Presentation/ViewModel Model Mapping (AutoMapper)   A Peak into View How view works in ASP.NET MVC? View Engine Design Custom View Engine View Best Practices Templated Helpers Partial Views   A Peak into Controller Introduction Controller Design Controller Best Practices Asynchronous Controller Custom Action Result Action Filters Controller Factory to use with IOC   Routes Explanation Routes from the database Routes from XML More complex routing   Master Pages Basics Setting Master Page Dynamically   Working with data in the view Repeating Views Array of check boxes Array of radio buttons Paged data CRUD Client side action Confirmation Dialog (modal window) jqGrid   Working with Forms   Validation Model Validation with DataAnnotations Using the xVal validation framework Client side validation with jQuery Validation Fluent Validation Model Binders   Templating Create strongly typed helper using T4 Custom View Templates with T4 Create custom MVC project template using T4   IOC AutoFac Ninject Unity Application   Areas   jQuery, Ajax and jQuery Plugins   State Maintenance Application State User state Cookies Webfarm   Error Handling View error handling Controller error handling ELMAH (Error Logging Modules and Handlers)   Authentication and Authorization User Registration form SignOn Process Password Reminder Membership and Roles Windows authentication Restricting access to all pages Restricting access to selected pages Restricting access to pages by role Restricting access to a controller Restricting access to selected area   Profiles and Themes Using Profiles Inheriting a Profile Migrating an anonymous profile Creating custom themes Using themes User personalized themes   Configuration Adding custom application settings in web.config Displaying custom error messages Accessing other web.config configuration elements Adding custom configuration elements to web.config Encrypting web.config sections   Tracing, Debugging and Logging   Caching Caching a whole page Caching pages based on route details Caching pages based on browser type and version Caching pages based custom strings Caching partial pages Caching application data Object Caching Using Microsoft Velocity Using MemCache Using AppFabric cache   Localization   HTTP Handlers and Modules   Security XSS/CSRF AnitForgery Encoding   HtmlHelpers Strongly typed helpers Writing custom helpers   Repository Pattern (Data access)   WF/WCF   Unit Testing   Mocking Framework   Integration Testing   Load / Performance Testing   Deployment    Once again let me know your thoughts on this.   Till then, Enjoy MVC'ing!!!

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• Give a session on C++ AMP – here is how

  - by Daniel Moth

  Ever since presenting on C++ AMP at the AMD Fusion conference in June, then the Gamefest conference in August, and the BUILD conference in September, I've had numerous requests about my material from folks that want to re-deliver the same session. The C++ AMP session I put together has evolved over the 3 presentations to its final form that I used at BUILD, so that is the one I recommend you base yours on. Please get the slides and the recording from channel9 (I'll refer to slide numbers below). This is how I've been presenting the C++ AMP session: Context (slide 3, 04:18-08:18) Start with a demo, on my dual-GPU machine. I've been using the N-Body sample (for VS 11 Developer Preview). (slide 4) Use an nvidia slide that has additional examples of performance improvements that customers enjoy with heterogeneous computing. (slide 5) Talk a bit about the differences today between CPU and GPU hardware, leading to the fact that these will continue to co-exist and that GPUs are great for data parallel algorithms, but not much else today. One is a jack of all trades and the other is a number cruncher. (slide 6) Use the APU example from amd, as one indication that the hardware space is still in motion, emphasizing that the C++ AMP solution is a data parallel API, not a GPU API. It has a future proof design for hardware we have yet to see. (slide 7) Provide more meta-data, as blogged about when I first introduced C++ AMP. Code (slide 9-11) Introduce C++ AMP coding with a simplistic array-addition algorithm – the slides speak for themselves. (slide 12-13) index<N>, extent<N>, and grid<N>. (Slide 14-16) array<T,N>, array_view<T,N> and comparison between them. (Slide 17) parallel_for_each. (slide 18, 21) restrict. (slide 19-20) actual restrictions of restrict(direct3d) – the slides speak for themselves. (slide 22) bring it altogether with a matrix multiplication example. (slide 23-24) accelerator, and accelerator_view. (slide 26-29) Introduce tiling incl. tiled matrix multiplication [tiling probably deserves a whole session instead of 6 minutes!]. IDE (slide 34,37) Briefly touch on the concurrency visualizer. It supports GPU profiling, but enhancements specific to C++ AMP we hope will come at the Beta timeframe, which is when I'll be spending more time talking about it. (slide 35-36, 51:54-59:16) Demonstrate the GPU debugging experience in VS 11. Summary (slide 39) Re-iterate some of the points of slide 7, and add the point that the C++ AMP spec will be open for other compiler vendors to implement, even on other platforms (in fact, Microsoft is actively working on that). (slide 40) Links to content – see slide – including where all your questions should go: http://social.msdn.microsoft.com/Forums/en/parallelcppnative/threads.   "But I don't have time for a full blown session, I only need 2 (or just 1, or 3) C++ AMP slides to use in my session on related topic X" If all you want is a small number of slides, you can take some from the session above and customize them. But because I am so nice, I have created some slides for you, including talking points in the notes section. Download them here. Comments about this post by Daniel Moth welcome at the original blog.

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• Ruby 1.9.3 segmentation fault on rackspace

  - by user531065

  I'm having a similar problem as "ruby 1.9 segmentation fault on exit." I followed the solution and updated libselinux with yum and have the following version installed: Package libselinux-2.0.96-6.fc14.1.x86_64 already installed and latest version I am running a RackSpace machine, kernel version: 2.6.35.4-rscloud. My C backtrace is: -- C level backtrace information ------------------------------------------- /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x18910a) [0x7f3cdb6c010a] vm_dump.c:796 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x5eb04) [0x7f3cdb595b04] error.c:258 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_bug+0xb8) [0x7f3cdb5969d8] error.c:277 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x119865) [0x7f3cdb650865] signal.c:609 /lib64/libpthread.so.0() [0x328540eeb0] /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x179272) [0x7f3cdb6b0272] ./include/ruby/ruby.h:1306 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x17f31b) [0x7f3cdb6b631b] vm.c:1220 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x1800d5) [0x7f3cdb6b70d5] vm.c:624 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_yield+0x44) [0x7f3cdb6bb274] vm.c:654 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0xab821) [0x7f3cdb5e2821] numeric.c:3204 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x183601) [0x7f3cdb6ba601] vm_insnhelper.c:404 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x1792b4) [0x7f3cdb6b02b4] insns.def:1015 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x17f31b) [0x7f3cdb6b631b] vm.c:1220 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x1800d5) [0x7f3cdb6b70d5] vm.c:624 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_yield+0x44) [0x7f3cdb6bb274] vm.c:654 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_ary_each+0x54) [0x7f3cdb5622e4] array.c:1478 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x183601) [0x7f3cdb6ba601] vm_insnhelper.c:404 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x1792b4) [0x7f3cdb6b02b4] insns.def:1015 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x17f31b) [0x7f3cdb6b631b] vm.c:1220 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_iseq_eval+0x1f0) [0x7f3cdb6bbae0] vm.c:1447 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x67bfd) [0x7f3cdb59ebfd] load.c:310 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_require_safe+0x6ef) [0x7f3cdb5a02df] load.c:619 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x183601) [0x7f3cdb6ba601] vm_insnhelper.c:404 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x1792b4) [0x7f3cdb6b02b4] insns.def:1015 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x17f31b) [0x7f3cdb6b631b] vm.c:1220 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x1800d5) [0x7f3cdb6b70d5] vm.c:624 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_yield+0x44) [0x7f3cdb6bb274] vm.c:654 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_ary_each+0x54) [0x7f3cdb5622e4] array.c:1478 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x183601) [0x7f3cdb6ba601] vm_insnhelper.c:404 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x1792b4) [0x7f3cdb6b02b4] insns.def:1015 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x17f31b) [0x7f3cdb6b631b] vm.c:1220 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(rb_iseq_eval_main+0xaf) [0x7f3cdb6bbbdf] vm.c:1461 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(+0x6471a) [0x7f3cdb59b71a] eval.c:204 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(ruby_exec_node+0x1d) [0x7f3cdb59c56d] eval.c:251 /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/libruby.so.1.9(ruby_run_node+0x1e) [0x7f3cdb59e60e] eval.c:244 ruby() [0x4008eb] /lib64/libc.so.6(__libc_start_main+0xfd) [0x3284c1ee5d] ruby() [0x4007d9]

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• Blog Buzz - Devoxx 2011

  - by Janice J. Heiss

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

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• C#/.NET Little Wonders &ndash; Cross Calling Constructors

  - by James Michael Hare

  Just a small post today, it’s the final iteration before our release and things are crazy here!  This is another little tidbit that I love using, and it should be fairly common knowledge, yet I’ve noticed many times that less experienced developers tend to have redundant constructor code when they overload their constructors. The Problem – repetitive code is less maintainable Let’s say you were designing a messaging system, and so you want to create a class to represent the properties for a Receiver, so perhaps you design a ReceiverProperties class to represent this collection of properties. Perhaps, you decide to make ReceiverProperties immutable, and so you have several constructors that you can use for alternative construction: 1: // Constructs a set of receiver properties. 2: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable, bool isBuffered) 3: { 4: ReceiverType = receiverType; 5: Source = source; 6: IsDurable = isDurable; 7: IsBuffered = isBuffered; 8: } 9: 10: // Constructs a set of receiver properties with buffering on by default. 11: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable) 12: { 13: ReceiverType = receiverType; 14: Source = source; 15: IsDurable = isDurable; 16: IsBuffered = true; 17: } 18:  19: // Constructs a set of receiver properties with buffering on and durability off. 20: public ReceiverProperties(ReceiverType receiverType, string source) 21: { 22: ReceiverType = receiverType; 23: Source = source; 24: IsDurable = false; 25: IsBuffered = true; 26: } Note: keep in mind this is just a simple example for illustration, and in same cases default parameters can also help clean this up, but they have issues of their own. While strictly speaking, there is nothing wrong with this code, logically, it suffers from maintainability flaws.  Consider what happens if you add a new property to the class?  You have to remember to guarantee that it is set appropriately in every constructor call. This can cause subtle bugs and becomes even uglier when the constructors do more complex logic, error handling, or there are numerous potential overloads (especially if you can’t easily see them all on one screen’s height). The Solution – cross-calling constructors I’d wager nearly everyone knows how to call your base class’s constructor, but you can also cross-call to one of the constructors in the same class by using the this keyword in the same way you use base to call a base constructor. 1: // Constructs a set of receiver properties. 2: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable, bool isBuffered) 3: { 4: ReceiverType = receiverType; 5: Source = source; 6: IsDurable = isDurable; 7: IsBuffered = isBuffered; 8: } 9: 10: // Constructs a set of receiver properties with buffering on by default. 11: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable) 12: : this(receiverType, source, isDurable, true) 13: { 14: } 15:  16: // Constructs a set of receiver properties with buffering on and durability off. 17: public ReceiverProperties(ReceiverType receiverType, string source) 18: : this(receiverType, source, false, true) 19: { 20: } Notice, there is much less code.  In addition, the code you have has no repetitive logic.  You can define the main constructor that takes all arguments, and the remaining constructors with defaults simply cross-call the main constructor, passing in the defaults. Yes, in some cases default parameters can ease some of this for you, but default parameters only work for compile-time constants (null, string and number literals).  For example, if you were creating a TradingDataAdapter that relied on an implementation of ITradingDao which is the data access object to retreive records from the database, you might want two constructors: one that takes an ITradingDao reference, and a default constructor which constructs a specific ITradingDao for ease of use: 1: public TradingDataAdapter(ITradingDao dao) 2: { 3: _tradingDao = dao; 4:  5: // other constructor logic 6: } 7:  8: public TradingDataAdapter() 9: { 10: _tradingDao = new SqlTradingDao(); 11:  12: // same constructor logic as above 13: }   As you can see, this isn’t something we can solve with a default parameter, but we could with cross-calling constructors: 1: public TradingDataAdapter(ITradingDao dao) 2: { 3: _tradingDao = dao; 4:  5: // other constructor logic 6: } 7:  8: public TradingDataAdapter() 9: : this(new SqlTradingDao()) 10: { 11: }   So in cases like this where you have constructors with non compiler-time constant defaults, default parameters can’t help you and cross-calling constructors is one of your best options. Summary When you have just one constructor doing the job of initializing the class, you can consolidate all your logic and error-handling in one place, thus ensuring that your behavior will be consistent across the constructor calls. This makes the code more maintainable and even easier to read.  There will be some cases where cross-calling constructors may be sub-optimal or not possible (if, for example, the overloaded constructors take completely different types and are not just “defaulting” behaviors). You can also use default parameters, of course, but default parameter behavior in a class hierarchy can be problematic (default values are not inherited and in fact can differ) so sometimes multiple constructors are actually preferable. Regardless of why you may need to have multiple constructors, consider cross-calling where you can to reduce redundant logic and clean up the code.   Technorati Tags: C#,.NET,Little Wonders

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• My Red Gate Experience

  - by Colin Rothwell

  I’m Colin, and I’ve been an intern working with Mike in publishing on Simple-Talk and SQLServerCentral for the past ten weeks. I’ve mostly been working “behind the scenes”, making improvements to the spam filtering, along with various other small tweaks. When I arrived at Red Gate, one of the first things Mike asked me was what I wanted to get out of the internship. It wasn’t a question I’d given a great deal of thought to, but my immediate response was the same as almost anybody: to support my growing family. Well, ok, not quite that, but money was certainly a motivator, along with simply making sure that I didn’t get bored over the summer. Three months is a long time to fill, and many of my friends end up getting bored, or worse, knitting obsessively. With the arrogance which seems fairly common among Cambridge people, I wasn’t expecting to really learn much here! In my mind, the part of the year where I am at Uni is the part where I learn things, whilst Red Gate would be an opportunity to apply what I’d learnt. Thankfully, the opposite is true: I’ve learnt a lot during my time here, and there has been a definite positive impact on the way I write code. The first thing I’ve really learnt is that test-driven development is, in general, a sensible way of working. Before coming, I didn’t really get it: how could you test something you hadn’t yet written? It didn’t make sense! My problem was seeing a test as having to test all the behaviour of a given function. Writing tests which test the bare minimum possible and building them up is a really good way of crystallising the direction the code needs to grow in, and ensures you never attempt to write too much code at time. One really good experience of this was early on in my internship when Mike and I were working on the query used to list active authors: I’d written something which I thought would do the trick, but by starting again using TDD we grew something which revealed that there were several subtle mistakes in the query I’d written. I’ve also been awakened to the value of pair programming. Whilst I could sort of see the point before coming, I also thought that it was impossible that two people would ever get more done at the same computer than if they were working separately. I still think that this is true for projects with pieces that developers can easily work on independently, and with developers who both know the codebase, but I’ve found that pair programming can be really good for learning a code base, and for building up small projects to the point where you can start working on separate components, as well as solving particularly difficult problems. Later on in my internship, for my down tools week project, I was working on adding Python support to Glimpse. Another intern and I we pair programmed the entire project, using ping pong pair programming as much as possible. One bonus that this brought which I wasn’t expecting was that I found myself less prone to distraction: with someone else peering over my shoulder, I didn’t have the ever-present temptation to open gmail, or facebook, or yammer, or twitter, or hacker news, or reddit, and so on, and so forth. I’m quite proud of this project: I think it’s some of the best code I’ve written. I’ve also been really won over to the value of descriptive variables names. In my pre-Red Gate life, as a lone-ranger style cowboy programmer, I’d developed a tendency towards laziness in variable names, sometimes abbreviating or, worse, using acronyms. I’ve swiftly realised that this is a bad idea when working with a team: saving a few key strokes is inevitably not worth it when it comes to reading code again in the future. Longer names also mean you can do away with a majority of comments. I appreciate that if you’ve come up with an O(n*log n) algorithm for something which seemed O(n^2), you probably want to explain how it works, but explaining what a variable name means is a big no no: it’s so very easy to change the behaviour of the code, whilst forgetting about the comments. Whilst at Red Gate, I took the opportunity to attend a code retreat, which really helped me to solidify all the things I’d learnt. To be completely free of any existing code base really lets you focus on best practises and think about how you write code. If you get a chance to go on a similar event, I’d highly recommend it! Cycling to Red Gate, I’ve also become much better at fitting inner tubes: if you’re struggling to get the tube out, or re-fit the tire, letting a bit of air out usually helps. I’ve also become quite a bit better at foosball and will miss having a foosball table! I’d like to finish off by saying thank you to everyone at Red Gate for having me. I’ve really enjoyed working with, and learning from, the team that brings you this web site. If you meet any of them, buy them a drink!

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• WebCenter Customer Spotlight: Ancestry.com

  - by me

  Author: Peter Reiser - Social Business Evangelist, Oracle WebCenter  Solution SummaryAncestry.com Inc is the largest for-profit genealogy company in the world and it operates a network of genealogical and historical record websites focused on the U.S. and nine foreign countries, develops and markets genealogical software, and offers a wide array of genealogical related services. As of June 2012, the company provided access to more than 10 billion records, 38 million family trees, and 2 million paying subscribers. Their main business challenges were to improve time to market and agility to respond quickly to fast changing Internet waves while integrating with their existing content (4 PetaByte) and legacy systems. Ancestry.com implemented Oracle WebCenter Sites as their Web Experience Management System for their landing pages and marketing micro sites, added dynamic sections to their existing websites and integrated the existing content and legacy systems through web services. The Ancestry.com landing pages and marketing sites are now managed by the business team without any involvement of engineering resources. Managed content can quickly be added to existing pages without having to refactor the whole page and existing content (4 PetaBytes)  is now served trough Oracle WebCenter Sites without having to migrate from existing systems. Company OverviewAncestry.com Inc is a publicly traded Internet company (NASDAQ: ACOM) based in Provo, Utah, USA. The largest for-profit genealogy company in the world, it operates a network of genealogical and historical record websites focused on the U.S. and nine foreign countries, develops and markets genealogical software, and offers a wide array of genealogical related services. As of June 2012, the company provided access to more than 10 billion records, 38 million family trees, and 2 million paying subscribers. Business ChallengesAncestry main business challenge was to respond quickly to fast changing Internet waves.  Product marketing could not change Web site content without going through development. They needed dedicated developers just to support their marketing efforts. Technical Requirements Support current systems and environments - ASP.NET, MVC.NET, Java, JSP, PHP Scalable and manageable for a world wide network Marketing Requirements Easy to enter content – Without having a degree in HTML Scheduling of content – When is content visible to users Product Requirements Easy to manage content – See when content is out-of-date Rotation of content – Producing new content as old content expires Solution DeployedAncestry implemented  Oracle WebCenter Sites as their Web Experience Management System to manage their landing pages and marketing micro sites. This sites are fully managed by their business team without involvement of any engineering resources. The integration with their existing Web sites is done through Spot Management which allows the ability to add dynamic content to certain sections of a web page. The dynamic content is managed by  Oracle WebCenter Sites. The integration with the existing content (4 PetaBytes!) is done trough  a custom content provider interface which allows to mix existing content with content from  Oracle WebCenter Sites. Business ResultsAncestry.com has achieved following impressive business results: Landing pages and marketing sites are now managed by the business team without any involvement of engineering resources Managed content can quickly be added to existing pages without having to refactor the whole page Provide access to existing content (4 PetaBytes)  without having to migrate from existing systems Additional Information Ancestry Webcast Oracle WebCenter Sites

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• Give a session on C++ AMP – here is how

  - by Daniel Moth

  Ever since presenting on C++ AMP at the AMD Fusion conference in June, then the Gamefest conference in August, and the BUILD conference in September, I've had numerous requests about my material from folks that want to re-deliver the same session. The C++ AMP session I put together has evolved over the 3 presentations to its final form that I used at BUILD, so that is the one I recommend you base yours on. Please get the slides and the recording from channel9 (I'll refer to slide numbers below). This is how I've been presenting the C++ AMP session: Context (slide 3, 04:18-08:18) Start with a demo, on my dual-GPU machine. I've been using the N-Body sample (for VS 11 Developer Preview). (slide 4) Use an nvidia slide that has additional examples of performance improvements that customers enjoy with heterogeneous computing. (slide 5) Talk a bit about the differences today between CPU and GPU hardware, leading to the fact that these will continue to co-exist and that GPUs are great for data parallel algorithms, but not much else today. One is a jack of all trades and the other is a number cruncher. (slide 6) Use the APU example from amd, as one indication that the hardware space is still in motion, emphasizing that the C++ AMP solution is a data parallel API, not a GPU API. It has a future proof design for hardware we have yet to see. (slide 7) Provide more meta-data, as blogged about when I first introduced C++ AMP. Code (slide 9-11) Introduce C++ AMP coding with a simplistic array-addition algorithm – the slides speak for themselves. (slide 12-13) index<N>, extent<N>, and grid<N>. (Slide 14-16) array<T,N>, array_view<T,N> and comparison between them. (Slide 17) parallel_for_each. (slide 18, 21) restrict. (slide 19-20) actual restrictions of restrict(direct3d) – the slides speak for themselves. (slide 22) bring it altogether with a matrix multiplication example. (slide 23-24) accelerator, and accelerator_view. (slide 26-29) Introduce tiling incl. tiled matrix multiplication [tiling probably deserves a whole session instead of 6 minutes!]. IDE (slide 34,37) Briefly touch on the concurrency visualizer. It supports GPU profiling, but enhancements specific to C++ AMP we hope will come at the Beta timeframe, which is when I'll be spending more time talking about it. (slide 35-36, 51:54-59:16) Demonstrate the GPU debugging experience in VS 11. Summary (slide 39) Re-iterate some of the points of slide 7, and add the point that the C++ AMP spec will be open for other compiler vendors to implement, even on other platforms (in fact, Microsoft is actively working on that). (slide 40) Links to content – see slide – including where all your questions should go: http://social.msdn.microsoft.com/Forums/en/parallelcppnative/threads.   "But I don't have time for a full blown session, I only need 2 (or just 1, or 3) C++ AMP slides to use in my session on related topic X" If all you want is a small number of slides, you can take some from the session above and customize them. But because I am so nice, I have created some slides for you, including talking points in the notes section. Download them here. Comments about this post by Daniel Moth welcome at the original blog.

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• Think before you animate

  - by David Paquette

  Animations are becoming more and more common in our applications.  With technologies like WPF, Silverlight and jQuery, animations are becoming easier for developers to use (and abuse).  When used properly, animation can augment the user experience.  When used improperly, animation can degrade the user experience.  Sometimes, the differences can be very subtle. I have recently made use of animations in a few projects and I very quickly realized how easy it is to abuse animation techniques.  Here are a few things I have learned along the way. 1) Don’t animate for the sake of animating We’ve all seen the PowerPoint slides with annoying slide transitions that animate 20 different ways.  It’s distracting and tacky.  The same holds true for your application.  While animations are fun and becoming easy to implement, resist the urge to use the technology just because you think the technology is amazing.   2) Animations should (and do) have meaning I recently built a simple Windows Phone 7 (WP7) application, Steeped (download it here).  The application has 2 pages.  The first page lists a number of tea types.  When the user taps on one of the tea types, the application navigates to the second page with information about that tea type and some options for the user to choose from.       One of the last things I did before submitting Steeped to the marketplace was add a page transition between the 2 pages.  I choose the Slide / Fade Out transition.  When the user selects a tea type, the main page slides to the left and fades out.  At the same time, the details page slides in from the right and fades in.  I tested it and thought it looked great so I submitted the app.  A few days later, I asked a friend to try the app.  He selected a tea type, and I was a little surprised by how he used the app.  When he wanted to navigate back to the main page, instead of pressing the back button on the phone, he tried to use a swiping gesture.  Of course, the swiping gesture did nothing because I had not implemented that feature.  After thinking about it for a while, I realized that the page transition I had chosen implied a particular behaviour.  As a user, if an action I perform causes an item (in this case the page) to move, then my expectation is that I should be able to move it back.  I have since added logic to handle the swipe gesture and I think the app flows much better now. When using animation, it pays to ask yourself:  What story does this animation tell my users?   3) Watch the replay Some animations might seem great initially but can get annoying over time.  When you use an animation in your application, make sure you try using it over and over again to make sure it doesn’t get annoying.  When I add an animation, I try watch it at least 25 times in a row.  After watching the animation repeatedly, I can make a more informed decision whether or not I should keep the animation.  Often, I end up shortening the length of the animations.   4) Don’t get in the users way An animation should never slow the user down.  When implemented properly, an animation can give a perceived bump in performance.  A good example of this is a the page transitions in most of the built in apps on WP7.  Obviously, these page animations don’t make the phone any faster, but they do provide a more responsive user experience.  Why?  Because most of the animations begin as soon as the user has performed some action.  The destination page might not be fully loaded yet, but the system responded immediately to user action, giving the impression that the system is more responsive.  If the user did not see anything happen until after the destination page was fully loaded, the application would feel clumsy and slow.  Also, it is important to make sure the animation does not degrade the performance (or perceived performance) of the application.   Jut a few things to consider when using animations.  As is the case with many technologies, we often learn how to misuse it before we learn how to use it effectively.

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• FBX Importer - Texture Name

  - by CmasterG

  I have a problem with the FBX SDK. I read in the data for the vertex position and the uv coordinates. It works fine, but now I want to read for each polygon to which texture it belongs, so that I can have models with multiple textures. Can anyone tell me how I can get the texture name (file name) for my polygon. My code to read in vertex position and uv coordinates is the following: int i, j, lPolygonCount = pMesh->GetPolygonCount(); FbxVector4* lControlPoints = pMesh->GetControlPoints(); int vertexId = 0; for (i = 0; i < lPolygonCount; i++) { int lPolygonSize = pMesh->GetPolygonSize(i); for (j = 0; j < lPolygonSize; j++) { int lControlPointIndex = pMesh->GetPolygonVertex(i, j); FbxVector4 pos = lControlPoints[lControlPointIndex]; current_model[vertex_index].x = pos.mData[0] - pivot_offset[0]; current_model[vertex_index].y = pos.mData[1] - pivot_offset[1]; current_model[vertex_index].z = pos.mData[2]- pivot_offset[2]; FbxVector4 vertex_normal; pMesh->GetPolygonVertexNormal(i,j, vertex_normal); current_model[vertex_index].nx = vertex_normal.mData[0]; current_model[vertex_index].ny = vertex_normal.mData[1]; current_model[vertex_index].nz = vertex_normal.mData[2]; //read in UV data FbxStringList lUVSetNameList; pMesh->GetUVSetNames(lUVSetNameList); //get lUVSetIndex-th uv set const char* lUVSetName = lUVSetNameList.GetStringAt(0); const FbxGeometryElementUV* lUVElement = pMesh->GetElementUV(lUVSetName); if(!lUVElement) continue; // only support mapping mode eByPolygonVertex and eByControlPoint if( lUVElement->GetMappingMode() != FbxGeometryElement::eByPolygonVertex && lUVElement->GetMappingMode() != FbxGeometryElement::eByControlPoint ) return; //index array, where holds the index referenced to the uv data const bool lUseIndex = lUVElement->GetReferenceMode() != FbxGeometryElement::eDirect; const int lIndexCount= (lUseIndex) ? lUVElement->GetIndexArray().GetCount() : 0; FbxVector2 lUVValue; //get the index of the current vertex in control points array int lPolyVertIndex = pMesh->GetPolygonVertex(i,j); //the UV index depends on the reference mode //int lUVIndex = lUseIndex ? lUVElement->GetIndexArray().GetAt(lPolyVertIndex) : lPolyVertIndex; int lUVIndex = pMesh->GetTextureUVIndex(i, j); lUVValue = lUVElement->GetDirectArray().GetAt(lUVIndex); current_model[vertex_index].tu = (float)lUVValue.mData[0]; current_model[vertex_index].tv = (float)lUVValue.mData[1]; vertex_index ++; } } float v1[3], v2[3], v3[3]; v1[0] = current_model[vertex_index - 3].x; v1[1] = current_model[vertex_index - 3].y; v1[2] = current_model[vertex_index - 3].z; v2[0] = current_model[vertex_index - 2].x; v2[1] = current_model[vertex_index - 2].y; v2[2] = current_model[vertex_index - 2].z; v3[0] = current_model[vertex_index - 1].x; v3[1] = current_model[vertex_index - 1].y; v3[2] = current_model[vertex_index - 1].z; collision_model->addTriangle(v1,v2,v3);

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• Issues glVertexAttribPointer last 2 parameters?

  - by NoobScratcher

  Introduction Hello I will start out by explaining my setup, showing samples as I go along explaining the situation. I'm using these tools: OpenGL 3.3 GLSL 330 C++ Problem The problem is when I render the wavefront obj 3d model it gives a very weird visual glitch the model was supposed to be a square but instead its a triangluated mess with parts of the vertexes pointing in a stretched direction in massive amounts towards the bottom left side of the frustum.... Explanation: I'm using std::vectors to store my wavefront .obj model data using sscanf to get the floating point values into the structure members x,y,z and store them into the Points structure variable p; int index = IndexAssigner(1, 1); ifstream file (list[index].c_str() ); points.push_back(Point()); Point p; int face[4]; while (!file.eof() ) { char modelbuffer[10000]; file.getline(modelbuffer, 10000); switch(modelbuffer[0]) { case 'v' : sscanf(modelbuffer, "v %f %f %f", &p.x, &p.y, &p.z); points.push_back(p); break; case 'f': sscanf(modelbuffer, "f %d %d %d %d", face, face+1, face+2, face+3 ); faces.push_back(face[0]); faces.push_back(face[1]); faces.push_back(face[2]); faces.push_back(face[3]); } //Turn on FileReader aka "RENDER CODE" FileReader = true; } then I render the Points vector using the .data() member of std::vectors to the frustum. Other declarations: int numfloats = 4; float* point=reinterpret_cast<float*>(&points[0]); int num_bytes=numfloats*sizeof(float); Vector declarations: struct Point {float x, y , z; }; std::vector<int>faces; std::vector<Point>points; Render code: glGenBuffers(1, &vertexbuffer); glGenTextures(1, &ModelTexture); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glBindTexture(GL_TEXTURE_3D, ModelTexture); glTexImage2D(GL_TEXTURE_2D, 0,GL_RGBA, ModelSurface->w, ModelSurface->h, 0, GL_BGR, GL_UNSIGNED_BYTE, ModelSurface->pixels); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glBufferData(GL_ARRAY_BUFFER, sizeof(points), points.data(), GL_STATIC_DRAW); glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE,num_bytes ,points.data()); glEnableVertexAttribArray(3); //Translation Process GLfloat TranslationMatrix[] = { 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 0.0, 1.0 }; //Send Translation Matrix up to the vertex shader glUniformMatrix4fv(translation, 1, TRUE, TranslationMatrix); glDrawElements( GL_QUADS, faces.size(), GL_UNSIGNED_INT, faces.data()); I tried looking at what was causing this and went through every function every parameter ,etc looked at the man pages. Then found out that it could be my glVertexAttribPointer. Here are the man pages for glVertexAttribPointer http://www.opengl.org/sdk/docs/man/xhtml/glVertexAttribPointer.xml The last 2 parameters is my problem How do I write those 2 last parameters do I try putting the data from Points into it?. glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE,num_bytes ,points.data()); How does it work with vectors? Is it fast?* if you can not be bothered too look at the man pages here is the scripts coming from the man pages directly. Stride Specifies the byte offset between consecutive generic vertex attributes. If stride is 0, the generic vertex attributes are understood to be tightly packed in the array. The initial value is 0. Pointer Specifies a pointer to the first component of the first generic vertex attribute in the array. The initial value is 0. If you want my full source - http://ideone.com/fPfkg Thanks Again if you do read this.

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• Texture displays on Android emulator but not on device

  - by Rob

  I have written a simple UI which takes an image (256x256) and maps it to a rectangle. This works perfectly on the emulator however on the phone the texture does not show, I see only a white rectangle. This is my code: public void onSurfaceCreated(GL10 gl, EGLConfig config) { byteBuffer = ByteBuffer.allocateDirect(shape.length * 4); byteBuffer.order(ByteOrder.nativeOrder()); vertexBuffer = byteBuffer.asFloatBuffer(); vertexBuffer.put(cardshape); vertexBuffer.position(0); byteBuffer = ByteBuffer.allocateDirect(shape.length * 4); byteBuffer.order(ByteOrder.nativeOrder()); textureBuffer = byteBuffer.asFloatBuffer(); textureBuffer.put(textureshape); textureBuffer.position(0); // Set the background color to black ( rgba ). gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Enable Smooth Shading, default not really needed. gl.glShadeModel(GL10.GL_SMOOTH); // Depth buffer setup. gl.glClearDepthf(1.0f); // Enables depth testing. gl.glEnable(GL10.GL_DEPTH_TEST); // The type of depth testing to do. gl.glDepthFunc(GL10.GL_LEQUAL); // Really nice perspective calculations. gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST); gl.glEnable(GL10.GL_TEXTURE_2D); loadGLTexture(gl); } public void onDrawFrame(GL10 gl) { gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); gl.glDisable(GL10.GL_DEPTH_TEST); gl.glMatrixMode(GL10.GL_PROJECTION); // Select Projection gl.glPushMatrix(); // Push The Matrix gl.glLoadIdentity(); // Reset The Matrix gl.glOrthof(0f, 480f, 0f, 800f, -1f, 1f); gl.glMatrixMode(GL10.GL_MODELVIEW); // Select Modelview Matrix gl.glPushMatrix(); // Push The Matrix gl.glLoadIdentity(); // Reset The Matrix gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY); gl.glLoadIdentity(); gl.glTranslatef(card.x, card.y, 0.0f); gl.glBindTexture(GL10.GL_TEXTURE_2D, texture[0]); //activates texture to be used now gl.glVertexPointer(2, GL10.GL_FLOAT, 0, vertexBuffer); gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer); gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4); gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY); } public void onSurfaceChanged(GL10 gl, int width, int height) { // Sets the current view port to the new size. gl.glViewport(0, 0, width, height); // Select the projection matrix gl.glMatrixMode(GL10.GL_PROJECTION); // Reset the projection matrix gl.glLoadIdentity(); // Calculate the aspect ratio of the window GLU.gluPerspective(gl, 45.0f, (float) width / (float) height, 0.1f, 100.0f); // Select the modelview matrix gl.glMatrixMode(GL10.GL_MODELVIEW); // Reset the modelview matrix gl.glLoadIdentity(); } public int[] texture = new int[1]; public void loadGLTexture(GL10 gl) { // loading texture Bitmap bitmap; bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.image); // generate one texture pointer gl.glGenTextures(0, texture, 0); //adds texture id to texture array // ...and bind it to our array gl.glBindTexture(GL10.GL_TEXTURE_2D, texture[0]); //activates texture to be used now // create nearest filtered texture gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST); gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR); // Use Android GLUtils to specify a two-dimensional texture image from our bitmap GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0); // Clean up bitmap.recycle(); } As per many other similar issues and resolutions on the web i have tried setting the minsdkversion is 3, loading the bitmap via an input stream bitmap = BitmapFactory.decodeStream(is), setting BitmapFactory.Options.inScaled to false, putting the images in the nodpi folder and putting them in the raw folder.. all of which didn't help. I'm not really sure what else to try..

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• University teaches DOS-style C++, how to deal with it

  - by gaidal

  Half a year ago I had a look at available programming educations. I chose this one because unlike most of the choices: The majority of the courses seemed to be about something concrete and useful; the languages used are C++ and Java which are platform-independent; later courses include developing for mobile devices and a course on Android development, which seemed modern and relevant. Now after two introductory courses we're just starting with C++, and my programming professor seems a bit weird. He's tested us on things like "why should you use constants" and "why are globals bad" in a kind of mechanical way, without much context, before teaching actual programming. His handouts use system("pause"), system("cls"), and getch() from some conio.h that seems ancient according to what I've read. I just did a task that was about printing the "ASCII letters from 32 to 255" (huh?), with an example picture showing a table with Windows' Extended ASCII - of course I got other results for 128-255 on my Arch Linux that uses Unicode, and this isn't mentioned at all. I don't know, it just doesn't seem right... As if he is teaching programming because he has to, perhaps? Should I bring such things up? Hmm. I was looking forward to learning from someone who really knows stuff, and in an academic, rigorous way, like SICP or something. Aren't professors in programming supposed to be like that? I studied math for a while and every teacher and assistant there were really precise about what they said, but this is my second programming teacher that is sort of disappointing. Oh well. Now, question: Is this what to expect from universities or Not OK, and how do I deal with it? I have never touched the language C++ (or C) until now, and am not the right person to jump up and say "This is So Wrong!", so if I google something and find 10 people who say "xxx is blasphemy", how do I skillfully communicate this? I do think it would be better for those classmates who are total beginners not to learn bad habits (such as these vibes of total ignorance of other platforms!) during the upcoming courses, but don't want to disrespect the teacher. I don't know if it's reasonable or just cocky to bring up things like "what about other platforms?" or "but what about this article or stackoverflow answer that I read that said..." for every assignment? Or, if he keeps ignoring non-Windows-programming, should I give up and focus on my own projects or somehow argue that this really isn't OK nowadays? Are there any programming teachers out there, what do you think? By the way these are web-based courses, all interaction between teachers and students takes place in a forum. EDIT: A few answers seem to be making some incorrect assumptions, so maybe I should add a few things. I have been doing programming for fun on and off for 10 years, am pretty comfortable in 3 languages and read programming blogs et c regularly. Also, I feel kind of done being a student, having a degree in another field. I just need another, relevant diploma to work as a programmer, so I'm going back for that. Studying computer science for 5 years is not for me anymore, even though I enjoy learning and solving problems in my free time. Second, let me highlight that I don't expect it to be like the industry at all, quite the contrary. I expect it to be academic, dry and unnecessarily correct. No, it's not just math. Every professor I have had in math, or Japanese (major) or Chinese (minor) have been very very academic, discussing subtle points for hours with passion. But the courses I'm taking now and a previous one in programming don't seem serious. They neither resemble industry NOR academia. That is the problem. And it's not because I can't learn programming anyway. Third, I don't necessarily want to learn C++ or Android development, and I know I could teach myself those and anything else if I wanted to. But I am going back to school anyway, and those platform-independent languages and mobile stuff made me think that maybe they're serious about teaching something relevant here. Seems like I got this wrong, but we'll see.

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• lvm disappeared after disc replacement on raid10

  - by user142295

  here my problem: I am running ubuntu 12.04 on a raid10 (4 disks), on top of which I installed an lvm with two volume groups (one for /, one for /home). The layout of the disks are as follows: Disk /dev/sda: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0003f3b6 Device Boot Start End Blocks Id System /dev/sda1 * 63 481949 240943+ 83 Linux /dev/sda2 481950 2910640634 1455079342+ fd Linux raid autodetect /dev/sda3 2910640635 2930272064 9815715 82 Linux swap / Solaris Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00069785 Device Boot Start End Blocks Id System /dev/sdb1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdb2 2910158685 2930272064 10056690 82 Linux swap / Solaris Disk /dev/sdc: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdc1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdc2 2910158685 2930272064 10056690 82 Linux swap / Solaris Disk /dev/sdd: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000f14de Device Boot Start End Blocks Id System /dev/sdd1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdd2 2910158685 2930272064 10056690 82 Linux swap / Solaris The first disk (/dev/sda) contains the /boot partition on /dev/sda1. I use grub2 to boot the system off this partition. On top of this raid10 I installed two volume groups, one for /, one for /home. This system worked well, I even exchanged two disks during the last two years. It always worked. But not this time. For the first time, /dev/sda broke. I do not know if this is an issue – I know I would have struggled anyways to overcome the problem with /boot installed on that disk and grub2 installed on the mbr of /dev/sda. Anyways, I did what I always did: start knoppix fire up the raid sudo mdadm --examine -scan which returns ARRAY /dev/md127 UUID=0dbf4558:1a943464:132783e8:19cdff95 start it up sudo mdadm --assemble /dev/md127 fail the failing disk (smart event) sudo mdadm /dev/md127 --fail /dev/sda2 remove the failing disk sudo mdadm /dev/md127 --remove /dev/sda2 stop the raid sudo mdadm -S /dev/md127 take out the disk replace it with a new one create the same partitions as on the failling one add it to the raid sudo mdadm --assemble /dev/md127 sudo mdadm /dev/md127 --add /dev/sda2 wait 4 hours All looks fine: cat /proc/mdstat returns: Personalities : [raid10] md127 : active raid10 sda2[0] sdd1[3] sdc1[2] sdb1[1] 2910158464 blocks 64K chunks 2 near-copies [4/4] [UUUU] unused devices: <none> and sudo mdadm --detail /dev/md127 returns /dev/md127: Version : 0.90 Creation Time : Wed Jun 10 13:08:46 2009 Raid Level : raid10 Array Size : 2910158464 (2775.34 GiB 2980.00 GB) Used Dev Size : 1455079232 (1387.67 GiB 1490.00 GB) Raid Devices : 4 Total Devices : 4 Preferred Minor : 127 Persistence : Superblock is persistent Update Time : Thu Mar 21 16:27:40 2013 State : clean Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : near=2 Chunk Size : 64K UUID : 0dbf4558:1a943464:132783e8:19cdff95 (local to host Microknoppix) Events : 0.4824680 Number Major Minor RaidDevice State 0 8 2 0 active sync /dev/sda2 1 8 17 1 active sync /dev/sdb1 2 8 33 2 active sync /dev/sdc1 3 8 49 3 active sync /dev/sdd1 However, there is no trace of the volume groups. Rebooting into knoppix does not help Restarting the old system (I actually replugged and re-added the failing disk for that – the system begins to start, but then fails to see the / partition – no wonder if the volume group is gone) does not help. sudo vgscan, sudo vgdisplay, sudo lvs, sudo lvdisplay, sudo vgscan –mknodes all returned No volume groups found. I am completely at a loss. Can anyone tell me if and how I can recover my data? Thanks in advance!

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• If the model is validating the data, shouldn't it throw exceptions on bad input?

  - by Carlos Campderrós

  Reading this SO question it seems that throwing exceptions for validating user input is frowned upon. But who should validate this data? In my applications, all validations are done in the business layer, because only the class itself really knows which values are valid for each one of its properties. If I were to copy the rules for validating a property to the controller, it is possible that the validation rules change and now there are two places where the modification should be made. Is my premise that validation should be done on the business layer wrong? What I do So my code usually ends up like this: <?php class Person { private $name; private $age; public function setName($n) { $n = trim($n); if (mb_strlen($n) == 0) { throw new ValidationException("Name cannot be empty"); } $this->name = $n; } public function setAge($a) { if (!is_int($a)) { if (!ctype_digit(trim($a))) { throw new ValidationException("Age $a is not valid"); } $a = (int)$a; } if ($a < 0 || $a > 150) { throw new ValidationException("Age $a is out of bounds"); } $this->age = $a; } // other getters, setters and methods } In the controller, I just pass the input data to the model, and catch thrown exceptions to show the error(s) to the user: <?php $person = new Person(); $errors = array(); // global try for all exceptions other than ValidationException try { // validation and process (if everything ok) try { $person->setAge($_POST['age']); } catch (ValidationException $e) { $errors['age'] = $e->getMessage(); } try { $person->setName($_POST['name']); } catch (ValidationException $e) { $errors['name'] = $e->getMessage(); } ... } catch (Exception $e) { // log the error, send 500 internal server error to the client // and finish the request } if (count($errors) == 0) { // process } else { showErrorsToUser($errors); } Is this a bad methodology? Alternate method Should maybe I create methods for isValidAge($a) that return true/false and then call them from the controller? <?php class Person { private $name; private $age; public function setName($n) { $n = trim($n); if ($this->isValidName($n)) { $this->name = $n; } else { throw new Exception("Invalid name"); } } public function setAge($a) { if ($this->isValidAge($a)) { $this->age = $a; } else { throw new Exception("Invalid age"); } } public function isValidName($n) { $n = trim($n); if (mb_strlen($n) == 0) { return false; } return true; } public function isValidAge($a) { if (!is_int($a)) { if (!ctype_digit(trim($a))) { return false; } $a = (int)$a; } if ($a < 0 || $a > 150) { return false; } return true; } // other getters, setters and methods } And the controller will be basically the same, just instead of try/catch there are now if/else: <?php $person = new Person(); $errors = array(); if ($person->isValidAge($age)) { $person->setAge($age); } catch (Exception $e) { $errors['age'] = "Invalid age"; } if ($person->isValidName($name)) { $person->setName($name); } catch (Exception $e) { $errors['name'] = "Invalid name"; } ... if (count($errors) == 0) { // process } else { showErrorsToUser($errors); } So, what should I do? I'm pretty happy with my original method, and my colleagues to whom I have showed it in general have liked it. Despite this, should I change to the alternate method? Or am I doing this terribly wrong and I should look for another way?

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• Pro/con of using Angular directives for complex form validation/ GUI manipulation

  - by tengen

  I am building a new SPA front end to replace an existing enterprise's legacy hodgepodge of systems that are outdated and in need of updating. I am new to angular, and wanted to see if the community could give me some perspective. I'll state my problem, and then ask my question. I have to generate several series of check boxes based on data from a .js include, with data like this: $scope.fieldMappings.investmentObjectiveMap = [ {'id':"CAPITAL PRESERVATION", 'name':"Capital Preservation"}, {'id':"STABLE", 'name':"Moderate"}, {'id':"BALANCED", 'name':"Moderate Growth"}, // etc {'id':"NONE", 'name':"None"} ]; The checkboxes are created using an ng-repeat, like this: <div ng-repeat="investmentObjective in fieldMappings.investmentObjectiveMap"> ... </div> However, I needed the values represented by the checkboxes to map to a different model (not just 2-way-bound to the fieldmappings object). To accomplish this, I created a directive, which accepts a destination array destarray which is eventually mapped to the model. I also know I need to handle some very specific gui controls, such as unchecking "None" if anything else gets checked, or checking "None" if everything else gets unchecked. Also, "None" won't be an option in every group of checkboxes, so the directive needs to be generic enough to accept a validation function that can fiddle with the checked state of the checkbox group's inputs based on what's already clicked, but smart enough not to break if there is no option called "NONE". I started to do that by adding an ng-click which invoked a function in the controller, but in looking around Stack Overflow, I read people saying that its bad to put DOM manipulation code inside your controller - it should go in directives. So do I need another directive? So far: (html): <input my-checkbox-group type="checkbox" fieldobj="investmentObjective" ng-click="validationfunc()" validationfunc="clearOnNone()" destarray="investor.investmentObjective" /> Directive code: .directive("myCheckboxGroup", function () { return { restrict: "A", scope: { destarray: "=", // the source of all the checkbox values fieldobj: "=", // the array the values came from validationfunc: "&" // the function to be called for validation (optional) }, link: function (scope, elem, attrs) { if (scope.destarray.indexOf(scope.fieldobj.id) !== -1) { elem[0].checked = true; } elem.bind('click', function () { var index = scope.destarray.indexOf(scope.fieldobj.id); if (elem[0].checked) { if (index === -1) { scope.destarray.push(scope.fieldobj.id); } } else { if (index !== -1) { scope.destarray.splice(index, 1); } } }); } }; }) .js controller snippet: .controller( 'SuitabilityCtrl', ['$scope', function ( $scope ) { $scope.clearOnNone = function() { // naughty jQuery DOM manipulation code that // looks at checkboxes and checks/unchecks as needed }; The above code is done and works fine, except the naughty jquery code in clearOnNone(), which is why I wrote this question. And here is my question: after ALL this, I think to myself - I could be done already if I just manually handled all this GUI logic and validation junk with jQuery written in my controller. At what point does it become foolish to write these complicated directives that future developers will have to puzzle over more than if I had just written jQuery code that 99% of us would understand with a glance? How do other developers draw the line? I see this all over Stack Overflow. For example, this question seems like it could be answered with a dozen lines of straightforward jQuery, yet he has opted to do it the angular way, with a directive and a partial... it seems like a lot of work for a simple problem. Specifically, I suppose I would like to know: how SHOULD I be writing the code that checks whether "None" has been selected (if it exists as an option in this group of checkboxes), and then check/uncheck the other boxes accordingly? A more complex directive? I can't believe I'm the only developer that is having to implement code that is more complex than needed just to satisfy an opinionated framework.

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• Storing non-content data in Orchard

  - by Bertrand Le Roy

  A CMS like Orchard is, by definition, designed to store content. What differentiates content from other kinds of data is rather subtle. The way I would describe it is by saying that if you would put each instance of a kind of data on its own web page, if it would make sense to add comments to it, or tags, or ratings, then it is content and you can store it in Orchard using all the convenient composition options that it offers. Otherwise, it probably isn't and you can store it using somewhat simpler means that I will now describe. In one of the modules I wrote, Vandelay.ThemePicker, there is some configuration data for the module. That data is not content by the definition I gave above. Let's look at how this data is stored and queried. The configuration data in question is a set of records, each of which has a number of properties: public class SettingsRecord { public virtual int Id { get; set;} public virtual string RuleType { get; set; } public virtual string Name { get; set; } public virtual string Criterion { get; set; } public virtual string Theme { get; set; } public virtual int Priority { get; set; } public virtual string Zone { get; set; } public virtual string Position { get; set; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Each property has to be virtual for nHibernate to handle it (it creates derived classed that are instrumented in all kinds of ways). We also have an Id property. The way these records will be stored in the database is described from a migration: public int Create() { SchemaBuilder.CreateTable("SettingsRecord", table => table .Column<int>("Id", column => column.PrimaryKey().Identity()) .Column<string>("RuleType", column => column.NotNull().WithDefault("")) .Column<string>("Name", column => column.NotNull().WithDefault("")) .Column<string>("Criterion", column => column.NotNull().WithDefault("")) .Column<string>("Theme", column => column.NotNull().WithDefault("")) .Column<int>("Priority", column => column.NotNull().WithDefault(10)) .Column<string>("Zone", column => column.NotNull().WithDefault("")) .Column<string>("Position", column => column.NotNull().WithDefault("")) ); return 1; } When we enable the feature, the migration will run, which will create the table in the database. Once we've done that, all we have to do in order to use the data is inject an IRepository<SettingsRecord>, which is what I'm doing from the set of helpers I put under the SettingsService class: private readonly IRepository<SettingsRecord> _repository; private readonly ISignals _signals; private readonly ICacheManager _cacheManager; public SettingsService( IRepository<SettingsRecord> repository, ISignals signals, ICacheManager cacheManager) { _repository = repository; _signals = signals; _cacheManager = cacheManager; } The repository has a Table property, which implements IQueryable<SettingsRecord> (enabling all kind of Linq queries) as well as methods such as Delete and Create. Here's for example how I'm getting all the records in the table: _repository.Table.ToList() And here's how I'm deleting a record: _repository.Delete(_repository.Get(r => r.Id == id)); And here's how I'm creating one: _repository.Create(new SettingsRecord { Name = name, RuleType = ruleType, Criterion = criterion, Theme = theme, Priority = priority, Zone = zone, Position = position }); In summary, you create a record class, a migration, and you're in business and can just manipulate the data through the repository that the framework is exposing. You even get ambient transactions from the work context.

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• Joining on NULLs

  - by Dave Ballantyne

  A problem I see on a fairly regular basis is that of dealing with NULL values.  Specifically here, where we are joining two tables on two columns, one of which is ‘optional’ ie is nullable.  So something like this: i.e. Lookup where all the columns are equal, even when NULL.   NULL’s are a tricky thing to initially wrap your mind around.  Statements like “NULL is not equal to NULL and neither is it not not equal to NULL, it’s NULL” can cause a serious brain freeze and leave you a gibbering wreck and needing your mummy. Before we plod on, time to setup some data to demo against. Create table #SourceTable ( Id integer not null, SubId integer null, AnotherCol char(255) not null ) go create unique clustered index idxSourceTable on #SourceTable(id,subID) go with cteNums as ( select top(1000) number from master..spt_values where type ='P' ) insert into #SourceTable select Num1.number,nullif(Num2.number,0),'SomeJunk' from cteNums num1 cross join cteNums num2 go Create table #LookupTable ( Id integer not null, SubID integer null ) go insert into #LookupTable Select top(100) id,subid from #SourceTable where subid is not null order by newid() go insert into #LookupTable Select top(3) id,subid from #SourceTable where subid is null order by newid() If that has run correctly, you will have 1 million rows in #SourceTable and 103 rows in #LookupTable.  We now want to join one to the other. First attempt – Lets just join select * from #SourceTable join #LookupTable on #LookupTable.id = #SourceTable.id and #LookupTable.SubID = #SourceTable.SubID OK, that’s a fail.  We had 100 rows back,  we didn’t correctly account for the 3 rows that have null values.  Remember NULL <> NULL and the join clause specifies SUBID=SUBID, which for those rows is not true. Second attempt – Lets deal with those pesky NULLS select * from #SourceTable join #LookupTable on #LookupTable.id = #SourceTable.id and isnull(#LookupTable.SubID,0) = isnull(#SourceTable.SubID,0) OK, that’s the right result, well done and 99.9% of the time that is where its left. It is a relatively trivial CPU overhead to wrap ISNULL around both columns and compare that result, so no problems.  But, although that’s true, this a relational database we are using here, not a procedural language.  SQL is a declarative language, we are making a request to the engine to get the results we want.  How we ask for them can make a ton of difference. Lets look at the plan for our second attempt, specifically the clustered index seek on the #SourceTable   There are 2 predicates. The ‘seek predicate’ and ‘predicate’.  The ‘seek predicate’ describes how SQLServer has been able to use an Index.  Here, it has been able to navigate the index to resolve where ID=ID.  So far so good, but what about the ‘predicate’ (aka residual probe) ? This is a row-by-row operation.  For each row found in the index matching the Seek Predicate, the leaf level nodes have been scanned and tested using this logical condition.  In this example [Expr1007] is the result of the IsNull operation on #LookupTable and that is tested for equality with the IsNull operation on #SourceTable.  This residual probe is quite a high overhead, if we can express our statement slightly differently to take full advantage of the index and make the test part of the ‘Seek Predicate’. Third attempt – X is null and Y is null So, lets state the query in a slightly manner: select * from #SourceTable join #LookupTable on #LookupTable.id = #SourceTable.id and ( #LookupTable.SubID = #SourceTable.SubID or (#LookupTable.SubID is null and #SourceTable.SubId is null) ) So its slightly wordier and may not be as clear in its intent to the human reader, that is what comments are for, but the key point is that it is now clearer to the query optimizer what our intention is. Let look at the plan for that query, again specifically the index seek operation on #SourceTable No ‘predicate’, just a ‘Seek Predicate’ against the index to resolve both ID and SubID.  A subtle difference that can be easily overlooked.  But has it made a difference to the performance ? Well, yes , a perhaps surprisingly high one. Clever query optimizer well done. If you are using a scalar function on a column, you a pretty much guaranteeing that a residual probe will be used.  By re-wording the query you may well be able to avoid this and use the index completely to resolve lookups. In-terms of performance and scalability your system will be in a much better position if you can.

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• How to place rooms proceduraly (rule based) on in a game word

  - by gardian06

  I am trying to design the algorithm for my level generation which is a rule driven system. I have created all the rules for the system. I have taken care to insure that all rooms make sense in a grid type setup. for example: these rooms could make this configuration The logic flow code that I have so far Door{ Vector3 position; POD orient; // 5 possible values (up is not an option) bool Open; } Room{ String roomRule; Vector3 roomPos; Vector3 dimensions; POD roomOrient; // 4 possible values List doors<Door>; } LevelManager{ float scale = 18f; List usedRooms<Room>; List openDoors<Door> bool Grid[][][]; Room CreateRoom(String rule, Vector3 position, POD Orient){ place recieved values based on rule fill in other data } Vector3 getDimenstions(String rule){ return dimensions of the room } RotateRoom(POD rotateAmount){ rotate all items in the room } MoveRoom(Room toBeMoved, POD orientataion, float distance){ move the position of the room based on inputs } GenerateMap(Vector3 size, Vector3 start, Vector3 end){ Grid = array[size.y][size.x][size.z]; Room floatingRoom; floatingRoom = Room.CreateRoom(S01, start, rand(4)); usedRooms.Add(floatingRoom); for each Door in floatingRoom.doors{ openDoors.Add(door); } // fill used grid spaces floatingRoom = Room.CreateRoom(S02, end, rand(4); usedRooms.Add(floatingRoom); for each Door in floatingRoom.doors{ openDoors.Add(door); } Vector3 nRoomLocation; Door workingDoor; string workingRoom; // fill used grid spaces // pick random door on the openDoors list workingDoor = /*randomDoor*/ // get a random rule nRoomLocation = workingDoor.position; // then I'm lost } } I know that I have to make sure for convergence (namely the end is reachable), and to do this until there are no more doors on the openDoors list. right now I am simply trying to get this to work in 2D (there are rules that introduce 3D), but I am working on a presumption that a rigorous algorithm can be trivially extended to 3D. EDIT: my thought pattern so far is to take an existing open door and then pick a random room (restrictions can be put in later) place that room's center at the doors location move the room in the direction of the doors orientation half the rooms dimension w/respect to that axis then test against the 3D array to see if all the grid points are open, or have been used, or if there is even space to put the room (caseEdge) if caseEdge (which can also occur in between rooms) then put the door on a toBeClosed list, and remove it from the open list (placing a wall or something there). then to do some kind of test that both the start, and the goal are connected, and reachable from each other (each room has nodes for AI, but I don't want to "have" to pull those out to accomplish this). but this logic has the problem for say the U, or L shaped rooms in my example, and then I also have a problem conceptually if the room needs to be rotated.

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