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  • How to display Sharepoint Data in a Windows Forms Application

    - by Michael M. Bangoy
    In this post I'm going to demonstrate how to retrieve Sharepoint data and display it on a Windows Forms Application. 1. Open Visual Studio 2010 and create a new Project. 2. In the project template select Windows Forms Application. 3. In order to communicate with Sharepoint from a Windows Forms Application we need to add the 2 Sharepoint Client DLL located in c:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\ISAPI. 4. Select the Microsoft.Sharepoint.Client.dll and Microsoft.Sharepoint.Client.Runtime.dll. (Your solution should look like the one below) 5. Open the Form1 in design view and from the Toolbox menu Add a Button, TextBox, Label and DataGridView on the form. 6. Next double click on the Load Button, this will open the code view of the form. Add Using statement to reference the Sharepoint Client Library then create two method for the Load Site Title and LoadList. See below:   using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Security; using System.Windows.Forms; using SP = Microsoft.SharePoint.Client;   namespace ClientObjectModel {     public partial class Form1 : Form     {         // url of the Sharepoint site         const string _context = "theurlofthesharepointsite";         public Form1()         {             InitializeComponent();         }         private void Form1_Load(object sender, EventArgs e)         {                    }         private void getsitetitle()         {             SP.ClientContext context = new SP.ClientContext(_context);             SP.Web _site = context.Web;             context.Load(_site);             context.ExecuteQuery();             txttitle.Text = _site.Title;             context.Dispose();         }                 private void loadlist()         {             using (SP.ClientContext _clientcontext = new SP.ClientContext(_context))             {                 SP.Web _web = _clientcontext.Web;                 SP.ListCollection _lists = _clientcontext.Web.Lists;                 _clientcontext.Load(_lists);                 _clientcontext.ExecuteQuery();                 DataTable dt = new DataTable();                 DataColumn column;                 DataRow row;                 column = new DataColumn();                 column.DataType = Type.GetType("System.String");                 column.ColumnName = "List Title";                 dt.Columns.Add(column);                 foreach (SP.List listitem in _lists)                 {                     row = dt.NewRow();                     row["List Title"] = listitem.Title;                     dt.Rows.Add(row);                 }                 dataGridView1.DataSource = dt;             }                   }       private void cmdload_Click(object sender, EventArgs e)         {             getsitetitle();             loadlist();          }     } } 7. That’s it. Hit F5 to run the application then click the Load Button. Your screen should like the one below. Hope this helps.

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  • Obtaining positional information in the IEnumerable Select extension method

    - by Kyle Burns
    This blog entry is intended to provide a narrow and brief look into a way to use the Select extension method that I had until recently overlooked. Every developer who is using IEnumerable extension methods to work with data has been exposed to the Select extension method, because it is a pretty critical piece of almost every query over a collection of objects.  The method is defined on type IEnumerable and takes as its argument a function that accepts an item from the collection and returns an object which will be an item within the returned collection.  This allows you to perform transformations on the source collection.  A somewhat contrived example would be the following code that transforms a collection of strings into a collection of anonymous objects: 1: var media = new[] {"book", "cd", "tape"}; 2: var transformed = media.Select( item => 3: { 4: Media = item 5: } ); This code transforms the array of strings into a collection of objects which each have a string property called Media. If every developer using the LINQ extension methods already knows this, why am I blogging about it?  I’m blogging about it because the method has another overload that I hadn’t seen before I needed it a few weeks back and I thought I would share a little about it with whoever happens upon my blog.  In the other overload, the function defined in the first overload as: 1: Func<TSource, TResult> is instead defined as: 1: Func<TSource, int, TResult>   The additional parameter is an integer representing the current element’s position in the enumerable sequence.  I used this information in what I thought was a pretty cool way to compare collections and I’ll probably blog about that sometime in the near future, but for now we’ll continue with the contrived example I’ve already started to keep things simple and show how this works.  The following code sample shows how the positional information could be used in an alternating color scenario.  I’m using a foreach loop because IEnumerable doesn’t have a ForEach extension, but many libraries do add the ForEach extension to IEnumerable so you can update the code if you’re using one of these libraries or have created your own. 1: var media = new[] {"book", "cd", "tape"}; 2: foreach (var result in media.Select( 3: (item, index) => 4: new { Item = item, Index = index })) 5: { 6: Console.ForegroundColor = result.Index % 2 == 0 7: ? ConsoleColor.Blue : ConsoleColor.Yellow; 8: Console.WriteLine(result.Item); 9: }

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  • Checking if an Unloaded Collection Contains Elements

    - by Ricardo Peres
    If you want to know if an unloaded collection in an entity contains elements, or count them, without actually loading them, you need to use a custom query; that is because the Count property (if the collection is not mapped with lazy=”extra”) and the LINQ Count() and Any() methods force the whole collection to be loaded. You can use something like these two methods, one for checking if there are any values, the other for actually counting them: 1: public static Boolean Exists(this ISession session, IEnumerable collection) 2: { 3: if (collection is IPersistentCollection) 4: { 5: IPersistentCollection col = collection as IPersistentCollection; 6:  7: if (col.WasInitialized == false) 8: { 9: String[] roleParts = col.Role.Split('.'); 10: String ownerTypeName = String.Join(".", roleParts, 0, roleParts.Length - 1); 11: String ownerCollectionName = roleParts.Last(); 12: String hql = "select 1 from " + ownerTypeName + " it where it.id = :id and exists elements(it." + ownerCollectionName + ")"; 13: Boolean exists = session.CreateQuery(hql).SetParameter("id", col.Key).List().Count == 1; 14:  15: return (exists); 16: } 17: } 18:  19: return ((collection as IEnumerable).OfType<Object>().Any()); 20: } 21:  22: public static Int64 Count(this ISession session, IEnumerable collection) 23: { 24: if (collection is IPersistentCollection) 25: { 26: IPersistentCollection col = collection as IPersistentCollection; 27:  28: if (col.WasInitialized == false) 29: { 30: String[] roleParts = col.Role.Split('.'); 31: String ownerTypeName = String.Join(".", roleParts, 0, roleParts.Length - 1); 32: String ownerCollectionName = roleParts.Last(); 33: String hql = "select count(elements(it." + ownerCollectionName + ")) from " + ownerTypeName + " it where it.id = :id"; 34: Int64 count = session.CreateQuery(hql).SetParameter("id", col.Key).UniqueResult<Int64>(); 35:  36: return (count); 37: } 38: } 39:  40: return ((collection as IEnumerable).OfType<Object>().Count()); 41: } Here’s how: 1: MyEntity entity = session.Load(100); 2:  3: if (session.Exists(entity.SomeCollection)) 4: { 5: Int32 count = session.Count(entity.SomeCollection); 6: //... 7: }

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  • Heterogeneous Datacenter Management with Enterprise Manager 12c

    - by Joe Diemer
    The following is a Guest Blog, contributed by Bryce Kaiser, Product Manager at Blue MedoraWhen I envision a perfect datacenter, it would consist of technologies acquired from a single vendor across the entire server, middleware, application, network, and storage stack - Apps to Disk - that meets your organization’s every IT requirement with absolute best-of-breed solutions in every category.   To quote a familiar motto, your datacenter would consist of "Hardware and Software, Engineered to Work Together".  In almost all cases, practical realities dictate something far less than the IT Utopia mentioned above.   You may wish to leverage multiple vendors to keep licensing costs down, a single vendor may not have an offering in the IT category you need, or your preferred vendor may quite simply not have the solution that meets your needs.    In other words, your IT needs dictate a heterogeneous IT environment.  Heterogeneity, however, comes with additional complexity. The following are two pretty typical challenges:1) No End-to-End Visibility into the Enterprise Wide Application Deployment. Each vendor solution which is added to an infrastructure may bring its own tooling creating different consoles for different vendor applications and platforms.2) No Visibility into Performance Bottlenecks. When multiple management tools operate independently, you lose diagnostic capabilities including identifying cross-tier issues with database, hung-requests, slowness, memory leaks and hardware errors/failures causing DB/MW issues. As adoption of Oracle Enterprise Manager (EM) has increased, especially since the release of Enterprise Manager 12c, Oracle has seen an increase in the number of customers who want to leverage their investments in EM to manage non-Oracle workloads.  Enterprise Manager provides a single pane of glass view into their entire datacenter.  By creating a highly extensible framework via the Oracle EM Extensibility Development Kit (EDK), Oracle has provided the tooling for business partners such as my company Blue Medora as well as customers to easily fill gaps in the ecosystem and enhance existing solutions.  As mentioned in the previous post on the Enterprise Manager Extensibility Exchange, customers have access to an assortment of Oracle and Partner provided solutions through this Exchange, which is accessed at http://www.oracle.com/goto/emextensibility.  Currently, there are over 80 Oracle and partner provided plug-ins across the EM 11g and EM 12c versions.  Blue Medora is one of those contributing partners, for which you will find 3 of our solutions including our flagship plugin for VMware.  Let's look at Blue Medora’s VMware plug-in as an example to what I'm trying to convey.  Here is a common situation solved by true visibility into your entire stack:Symptoms•    My database is bogging down, however the database appears okay internally.  Maybe it’s starved for resources?•    My OS tooling is showing everything is “OK”.  Something doesn’t add up. Root cause•    Through the VMware plugin we can see the problem is actually on the virtualization layer Solution•    From within Enterprise Manager  -- the same tool you use for all of your database tuning -- we can overlay the data of the database target, host target, and virtual machine target for a true picture of the true root cause. Here is the console view: Perhaps your monitoring conditions are more specific to your environment.  No worries, Enterprise Manager still has you covered.  With Metric Extensions you have the “Next Generation” of User-Defined Metrics, which easily bring the power of your existing management scripts into a single console while leveraging the proven Enterprise Manager framework. Simply put, Oracle Enterprise manager boasts a growing ecosystem that provides the single pane of glass for your entire datacenter from the database and beyond.  Bryce can be contacted at [email protected]

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  • C# Dev - I've tried Lisps, but I don't get it.

    - by Jonathan Mitchem
    After a few months of learning about and playing with lisps, both CL and a bit of Clojure, I'm still not seeing a compelling reason to write anything in it instead of C#. I would really like some compelling reasons, or for someone to point out that I'm missing something really big. The strengths of a Lisp (per my research): Compact, expressive notation - More so than C#, yes... but I seem to be able to express those ideas in C# too. Implicit support for functional programming - C# with LINQ extension methods: mapcar = .Select( lambda ) mapcan = .Select( lambda ).Aggregate( (a,b) = a.Union(b) ) car/first = .First() cdr/rest = .Skip(1) .... etc. Lambda and higher-order function support - C# has this, and the syntax is arguably simpler: "(lambda (x) ( body ))" versus "x = ( body )" "#(" with "%", "%1", "%2" is nice in Clojure Method dispatch separated from the objects - C# has this through extension methods Multimethod dispatch - C# does not have this natively, but I could implement it as a function call in a few hours Code is Data (and Macros) - Maybe I haven't "gotten" macros, but I haven't seen a single example where the idea of a macro couldn't be implemented as a function; it doesn't change the "language", but I'm not sure that's a strength DSLs - Can only do it through function composition... but it works Untyped "exploratory" programming - for structs/classes, C#'s autoproperties and "object" work quite well, and you can easily escalate into stronger typing as you go along Runs on non-Windows hardware - Yeah, so? Outside of college, I've only known one person who doesn't run Windows at home, or at least a VM of Windows on *nix/Mac. (Then again, maybe this is more important than I thought and I've just been brainwashed...) The REPL for bottom-up design - Ok, I admit this is really really nice, and I miss it in C#. Things I'm missing in a Lisp (due to a mix of C#, .NET, Visual Studio, Resharper): Namespaces. Even with static methods, I like to tie them to a "class" to categorize their context (Clojure seems to have this, CL doesn't seem to.) Great compile and design-time support the type system allows me to determine "correctness" of the datastructures I pass around anything misspelled is underlined realtime; I don't have to wait until runtime to know code improvements (such as using an FP approach instead of an imperative one) are autosuggested GUI development tools: WinForms and WPF (I know Clojure has access to the Java GUI libraries, but they're entirely foreign to me.) GUI Debugging tools: breakpoints, step-in, step-over, value inspectors (text, xml, custom), watches, debug-by-thread, conditional breakpoints, call-stack window with the ability to jump to the code at any level in the stack (To be fair, my stint with Emacs+Slime seemed to provide some of this, but I'm partial to the VS GUI-driven approach) I really like the hype surrounding Lisps and I gave it a chance. But is there anything I can do in a Lisp that I can't do as well in C#? It might be a bit more verbose in C#, but I also have autocomplete. What am I missing? Why should I use Clojure/CL?

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  • How to retrieve Sharepoint data from a Windows Forms Application.

    - by Michael M. Bangoy
    In this demo I'm going to demonstrate how to retrieve Sharepoint data and display it on a Windows Forms Application. 1. Open Visual Studio 2010 and create a new Project. 2. In the project template select Windows Forms Application. 3. In order to communicate with Sharepoint from a Windows Forms Application we need to add the 2 Sharepoint Client DLL located in c:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\ISAPI. 4. Select the Microsoft.Sharepoint.Client.dll and Microsoft.Sharepoint.Client.Runtime.dll. That's it we're ready to write our codes. Note: In this example I've added to controls on the form, the controls are Button, TextBox, Label and DataGridView. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Data.Objects; using System.Drawing; using System.Linq; using System.Text; using System.Security; using System.Windows.Forms; using SP = Microsoft.SharePoint.Client; namespace ClientObjectModel { public partial class Form1 : Form { // declare string url of the Sharepoint site string _context = "theurlofyoursharepointsite"; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { } private void getsitetitle() {    SP.ClientContext context = new SP.ClientContext(_context);    SP.Web _site = context.Web;    context.Load(_site);    context.ExecuteQuery();    txttitle.Text = _site.Title;    context.Dispose(); } private void loadlist() { using (SP.ClientContext _clientcontext = new SP.ClientContext(_context)) {    SP.Web _web = _clientcontext.Web;    SP.ListCollection _lists = _clientcontext.Web.Lists;    _clientcontext.Load(_lists);    _clientcontext.ExecuteQuery();    DataTable dt = new DataTable();    DataColumn column;    DataRow row;    column = new DataColumn();    column.DataType = Type.GetType("System.String");    column.ColumnName = "List Title";    dt.Columns.Add(column);    foreach (SP.List listitem in _lists)    {       row = dt.NewRow();       row["List Title"] = listitem.Title;       dt.Rows.Add(row);    }       dataGridView1.DataSource = dt;    } private void cmdload_Click(object sender, EventArgs e) { getsitetitle(); loadlist(); } } That's it. Running the application and clicking the Load Button will retrieve the Title of the Sharepoint site and display it on the TextBox and also it will retrieve ALL of the Sharepoint List on that site and populate the DataGridView with the List Title. Hope this helps. Thank you.

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  • Getting the number of fragments which passed the depth test

    - by Etan
    In "modern" environments, the "NV Occlusion Query" extension provides a method to get the number of fragments which passed the depth test. However, on the iPad / iPhone using OpenGL ES, the extension is not available. What is the most performant approach to implement a similar behaviour in the fragment shader? Some of my ideas: Render the object completely in white, then count all the colors together using a two-pass shader where first a vertical line is rendered and for each fragment the shader computes the sum over the whole row. Then, a single vertex is rendered whose fragment sums all the partial sums of the first pass. Doesn't seem to be very efficient. Render the object completely in white over a black background. Downsample recursively, abusing the hardware linear interpolation between textures until being at a reasonably small resolution. This leads to fragments which have a greyscale level depending on the number of white pixels where in their corresponding region. Is this even accurate enough? Use mipmaps and simply read the pixel on the 1x1 level. Again the question of accuracy and if it is even possible using non-power-of-two textures. The problem wit these approaches is, that the pipeline gets stalled which results in major performance issues. Therefore, I'm looking for a more performant way to accomplish my goal. Using the EXT_OCCLUSION_QUERY_BOOLEAN extension Apple introduced EXT_OCCLUSION_QUERY_BOOLEAN in iOS 5.0 for iPad 2. "4.1.6 Occlusion Queries Occlusion queries use query objects to track the number of fragments or samples that pass the depth test. An occlusion query can be started and finished by calling BeginQueryEXT and EndQueryEXT, respectively, with a target of ANY_SAMPLES_PASSED_EXT or ANY_SAMPLES_PASSED_CONSERVATIVE_EXT. When an occlusion query is started with the target ANY_SAMPLES_PASSED_EXT, the samples-boolean state maintained by the GL is set to FALSE. While that occlusion query is active, the samples-boolean state is set to TRUE if any fragment or sample passes the depth test. When the occlusion query finishes, the samples-boolean state of FALSE or TRUE is written to the corresponding query object as the query result value, and the query result for that object is marked as available. If the target of the query is ANY_SAMPLES_PASSED_CONSERVATIVE_EXT, an implementation may choose to use a less precise version of the test which can additionally set the samples-boolean state to TRUE in some other implementation dependent cases." The first sentence hints on a behavior which is exactly what I'm looking for: getting the number of pixels which passed the depth test in an asynchronous manner without much performance loss. However, the rest of the document describes only how to get boolean results. Is it possible to exploit this extension to get the pixel count? Does the hardware support it so that there may be hidden API to get access to the pixel count? Other extensions which could be exploitable would be debugging features like the number of times the fragment shader was invoked (PSInvocations in DirectX - not sure if something simila is available in OpenGL ES). However, this would also result in a pipeline stall.

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  • Gettings Terms asscoiated to a Specific list item

    - by Gino Abraham
    I had a fancy requirement where i had to get all tags associated to a document set in a document library. The normal tag could webpart was not working when i add it to the document set home page, so planned a custom webpart. Was checking in net to find a straight forward way to achieve this, but was not lucky enough to get something. Since i didnt get any samples in net, i looked into Microsoft.Sharerpoint.Portal.Webcontrols and found a solution.The socialdataframemanager control in 14Hive/Template/layouts/SocialDataFrame.aspx directed me to the solution. You can get the dll from ISAPI folder. Following Code snippet can get all Terms associated to the List Item given that you have list name and id for the list item. using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.SharePoint; using Microsoft.Office.Server.SocialData; namespace TagChecker { class Program { static void Main(string[] args) { // Your site url string siteUrl = http://contoso; // List Name string listName = "DocumentLibrary1"; // List Item Id for which you want to get all terms int listItemId = 35; using (SPSite site = new SPSite(siteUrl)) { using(SPWeb web = site.OpenWeb()) { SPListItem listItem = web.Lists[listName].GetItemById(listItemId); string url = string.Empty; // Based on the list type the url would be formed. Code Sniffed from Micosoft dlls :) if (listItem.ParentList.BaseType == SPBaseType.DocumentLibrary) { url = listItem.Web.Url.TrimEnd(new char[] { '/' }) + "/" + listItem.Url.TrimStart(new char[] { '/' }); } else if (SPFileSystemObjectType.Folder == listItem.FileSystemObjectType) { url = listItem.Web.Url.TrimEnd(new char[] { '/' }) + "/" + listItem.Folder.Url.TrimStart(new char[] { '/' }); } else { url = listItem.Web.Url.TrimEnd(new char[] { '/' }) + "/" + listItem.ParentList.Forms[PAGETYPE.PAGE_DISPLAYFORM].Url.TrimStart(new char[] { '/' }) + "?ID=" + listItem.ID.ToString(); } SPServiceContext serviceContext = SPServiceContext.GetContext(site); Uri uri = new Uri(url); SocialTagManager mgr = new SocialTagManager(serviceContext); SocialTerm[] terms = mgr.GetTerms(uri); foreach (SocialTerm term in terms) { Console.WriteLine(term.Term.Labels[0].Value ); } } } Console.Read(); } } } Reference dlls added are Microsoft.Sharepoint , Microsoft.Sharepoint.Taxonomy, Microsoft.office.server, Microsoft.Office.Server.UserProfiles from ISAPI folder. This logic can be used to make a custom tag cloud webpart by taking code from OOB tag cloud, so taht you can have you webpart anywhere in the site and still get Tags added to a specifc libdary/List. Hope this helps some one.

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  • Mutable Records in F#

    - by MarkPearl
    I’m loving my expert F# book – today I thought I would give a post on using mutable records as covered in Chapter 4 of Expert F#. So as they explain the simplest mutable data structures in F# are mutable records. The whole concept of things by default being immutable is a new one for me from my C# background. Anyhow… lets look at some C# code first. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace MutableRecords { public class DiscreteEventCounter { public int Total { get; set; } public int Positive { get; set; } public string Name { get; private set; } public DiscreteEventCounter(string name) { Name = name; } } class Program { private static void recordEvent(DiscreteEventCounter s, bool isPositive) { s.Total += 1; if (isPositive) s.Positive += 1; } private static void reportStatus (DiscreteEventCounter s) { Console.WriteLine("We have {0} {1} out of {2}", s.Positive, s.Name, s.Total); } static void Main(string[] args) { var longCounter = new DiscreteEventCounter("My Discrete Counter"); recordEvent(longCounter, true); recordEvent(longCounter, true); reportStatus(longCounter); Console.ReadLine(); } } } Quite simple, we have a class that has a few values. We instantiate an instance of the class and perform increments etc on the instance. Now lets look at an equivalent F# sample. namespace EncapsulationNS module Module1 = open System type DiscreteEventCounter = { mutable Total : int mutable Positive : int Name : string } let recordEvent (s: DiscreteEventCounter) isPositive = s.Total <- s.Total+1 if isPositive then s.Positive <- s.Positive+1 let reportStatus (s: DiscreteEventCounter) = printfn "We have %d %s out of %d" s.Positive s.Name s.Total let newCounter nm = { Total = 0; Positive = 0; Name = nm } // // Using it... // let longCounter = newCounter "My Discrete Counter" recordEvent longCounter (true) recordEvent longCounter (true) reportStatus longCounter System.Console.ReadLine() Notice in the type declaration of the DiscreteEventCounter we had to explicitly declare that the total and positive value holders were mutable. And that’s it – a very simple example of mutable types.

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  • SQL 2014 does data the way developers want

    - by Rob Farley
    A post I’ve been meaning to write for a while, good that it fits with this month’s T-SQL Tuesday, hosted by Joey D’Antoni (@jdanton) Ever since I got into databases, I’ve been a fan. I studied Pure Maths at university (as well as Computer Science), and am very comfortable with Set Theory, which undergirds relational database concepts. But I’ve also spent a long time as a developer, and appreciate that that databases don’t exactly fit within the stuff I learned in my first year of uni, particularly the “Algorithms and Data Structures” subject, in which we studied concepts like linked lists. Writing in languages like C, we used pointers to quickly move around data, without a database in sight. Of course, if we had a power failure all this data was lost, as it was only persisted in RAM. Perhaps it’s why I’m a fan of database internals, of indexes, latches, execution plans, and so on – the developer in me wants to be reassured that we’re getting to the data as efficiently as possible. Back when SQL Server 2005 was approaching, one of the big stories was around CLR. Many were saying that T-SQL stored procedures would be a thing of the past because we now had CLR, and that obviously going to be much faster than using the abstracted T-SQL. Around the same time, we were seeing technologies like Linq-to-SQL produce poor T-SQL equivalents, and developers had had a gutful. They wanted to move away from T-SQL, having lost trust in it. I was never one of those developers, because I’d looked under the covers and knew that despite being abstracted, T-SQL was still a good way of getting to data. It worked for me, appealing to both my Set Theory side and my Developer side. CLR hasn’t exactly become the default option for stored procedures, although there are plenty of situations where it can be useful for getting faster performance. SQL Server 2014 is different though, through Hekaton – its In-Memory OLTP environment. When you create a table using Hekaton (that is, a memory-optimized one), the table you create is the kind of thing you’d’ve made as a developer. It creates code in C leveraging structs and pointers and arrays, which it compiles into fast code. When you insert data into it, it creates a new instance of a struct in memory, and adds it to an array. When the insert is committed, a small write is made to the transaction to make sure it’s durable, but none of the locking and latching behaviour that typifies transactional systems is needed. Indexes are done using hashes and using bw-trees (which avoid locking through the use of pointers) and by handling each updates as a delete-and-insert. This is data the way that developers do it when they’re coding for performance – the way I was taught at university before I learned about databases. Being done in C, it compiles to very quick code, and although these tables don’t support every feature that regular SQL tables do, this is still an excellent direction that has been taken. @rob_farley

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  • In hindsight, is basing XAML on XML a mistake or a good approach?

    - by romkyns
    XAML is essentially a subset of XML. One of the main benefits of basing XAML on XML is said to be that it can be parsed with existing tools. And it can, to a large degree, although the (syntactically non-trivial) attribute values will stay in text form and require further parsing. There are two major alternatives to describing a GUI in an XML-derived language. One is to do what WinForms did, and describe it in real code. There are numerous problems with this, though it’s not completely advantage-free (a question to compare XAML to this approach). The other major alternative is to design a completely new syntax specifically tailored for the task at hand. This is generally known as a domain-specific language. So, in hindsight, and as a lesson for the future generations, was it a good idea to base XAML on XML, or would it have been better as a custom-designed domain-specific language? If we were designing an even better UI framework, should we pick XML or a custom DSL? Since it’s much easier to think positively about the status quo, especially one that is quite liked by the community, I’ll give some example reasons for why building on top of XML might be considered a mistake. Basing a language off XML has one thing going for it: it’s much easier to parse (the core parser is already available), requires much, much less design work, and alternative parsers are also much easier to write for 3rd party developers. But the resulting language can be unsatisfying in various ways. It is rather verbose. If you change the type of something, you need to change it in the closing tag. It has very poor support for comments; it’s impossible to comment out an attribute. There are limitations placed on the content of attributes by XML. The markup extensions have to be built "on top" of the XML syntax, not integrated deeply and nicely into it. And, my personal favourite, if you set something via an attribute, you use completely different syntax than if you set the exact same thing as a content property. It’s also said that since everyone knows XML, XAML requires less learning. Strictly speaking this is true, but learning the syntax is a tiny fraction of the time spent learning a new UI framework; it’s the framework’s concepts that make the curve steep. Besides, the idiosyncracies of an XML-based language might actually add to the "needs learning" basket. Are these disadvantages outweighted by the ease of parsing? Should the next cool framework continue the tradition, or invest the time to design an awesome DSL that can’t be parsed by existing tools and whose syntax needs to be learned by everyone? P.S. Not everyone confuses XAML and WPF, but some do. XAML is the XML-like thing. WPF is the framework with support for bindings, theming, hardware acceleration and a whole lot of other cool stuff.

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  • Assessing Relative Maintainability

    - by João Bragança
    We (a contractor, actually) are implementing an off the shelf system to replace a legacy homegrown system for the core domain of the company (designing widgets). Unfortunately both systems will have to run concurrently for some time, as the product just isn't ready yet. Also, the decision was made to only migrate some of the widgets from the legacy system, based on date of last sale activity. Later on a new requirement came down: certain people in the company, most of them outside of the widget development context, want to search all widgets. The search results screen has 3 pieces of data: a GUID, a human readable id that is searchable, and a brief description (may need to be searchable in the future). In the widget details, there will be multiple screens. These screens align very well along SOA / bounded context lines - a screen for marketing data, a screen for sales history, etc. UML ahead! I am probably using the wrong kind of arrows here so please forgive me. The current solution - which is not in production yet - is something like the following: Both systems will be queried and the controller will merge the results. The new system has its own proprietary query language (we've alleviated this a bit with a LINQ provider). It also puts a lot of data on the wire. 15 search results typically run about 60k of unintelligible SOAP-wrapped xml. So I would prefer to avoid querying this system directly. These two systems publish events to help us integrate with other systems, mainly an ERP system. One of these events contains all the data necessary for the search screen. I proposed the following alternative: However I am being told that 'adding another database' will create more maintenance down the road. However, I believe this to be false, as I had to add a relatively simple feature that took several hours longer than anticipated because of this merging code. I want to get a feel for which system is more maintainable in the long run. I personally have not had the burden of maintaining any large system. I want something more than my gut. Specifically I'd like to know if having more, specialized physical databases is more or less maintainable than having less larger physical databases.

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  • How to use DoDirect/Paypal Pro in asp.net?

    - by ptahiliani
    using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Net;using System.IO;using System.Collections;public partial class Default2 : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {    }    protected void Button1_Click(object sender, EventArgs e)    {        //API Credentials (3-token)        string strUsername = "<<enter your sandbox username here>>";        string strPassword = "<<enter your sandbox password here>>";        string strSignature = "<<enter your signature here>>";        string strCredentials = "USER=" + strUsername + "&PWD=" + strPassword + "&SIGNATURE=" + strSignature;        string strNVPSandboxServer = "https://api-3t.sandbox.paypal.com/nvp";        string strAPIVersion = "2.3";        string strNVP = strCredentials + "&METHOD=DoDirectPayment" +        "&CREDITCARDTYPE=" + "Visa" +        "&ACCT=" + "4710496235600346" +        "&EXPDATE=" + "10" + "2017" +        "&CVV2=" + "123" +        "&AMT=" + "12.34" +        "&FIRSTNAME=" + "Demo" +        "&LASTNAME=" + "User" +        "&IPADDRESS=192.168.2.236" +        "&STREET=" + "Lorem-1" +        "&CITY=" + "Lipsum-1" +        "&STATE=" + "Lorem" +        "&COUNTRY=" + "INDIA" +        "&ZIP=" + "302004" +        "&COUNTRYCODE=IN" +        "&PAYMENTACTION=Sale" +        "&VERSION=" + strAPIVersion;        try        {            //Create web request and web response objects, make sure you using the correct server (sandbox/live)            HttpWebRequest wrWebRequest = (HttpWebRequest)WebRequest.Create(strNVPSandboxServer);            wrWebRequest.Method = "POST";            StreamWriter requestWriter = new StreamWriter(wrWebRequest.GetRequestStream());            requestWriter.Write(strNVP);            requestWriter.Close();            // Get the response.            HttpWebResponse hwrWebResponse = (HttpWebResponse)wrWebRequest.GetResponse();            StreamReader responseReader = new StreamReader(wrWebRequest.GetResponse().GetResponseStream());            //and read the response            string responseData = responseReader.ReadToEnd();            responseReader.Close();            string result = Server.UrlDecode(responseData);            string[] arrResult = result.Split('&');            Hashtable htResponse = new Hashtable();            string[] responseItemArray;            foreach (string responseItem in arrResult)            {                responseItemArray = responseItem.Split('=');                htResponse.Add(responseItemArray[0], responseItemArray[1]);            }            string strAck = htResponse["ACK"].ToString();            if (strAck == "Success" || strAck == "SuccessWithWarning")            {                string strAmt = htResponse["AMT"].ToString();                string strCcy = htResponse["CURRENCYCODE"].ToString();                string strTransactionID = htResponse["TRANSACTIONID"].ToString();                //ordersDataSource.InsertParameters["TransactionID"].DefaultValue = strTransactionID;                string strSuccess = "Thank you, your order for: $" + strAmt + " " + strCcy + " has been processed.";                //successLabel.Text = strSuccess;                Response.Write(strSuccess.ToString());            }            else            {                string strErr = "Error: " + htResponse["L_LONGMESSAGE0"].ToString();                string strErrcode = "Error code: " + htResponse["L_ERRORCODE0"].ToString();                //errLabel.Text = strErr;                //errcodeLabel.Text = strErrcode;                Response.Write(strErr.ToString() + "<br/>" + strErrcode.ToString());                return;            }        }        catch (Exception ex)        {            // do something to catch the error, like write to a log file.            Response.Write("error processing");        }    }}

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  • The long road to bug-free software

    - by Tony Davis
    The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

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  • Video works with 'Try me' but not after install. What is the difference? U12.04LTS,

    - by HarveyP
    My hard drive got corrupted so I did a reinstall. Tested Youtube in FF during 'try me' and it worked - jerky, but it worked. Instal without all the updates (576 outstanding now) in order to get ff installed as per the demo - to no avail. In 'try me' mode ff NEVER crashed! After install ff crashed whilst I was typing in 'youtube' in the address field. When I finally got to youtube - no video. What is the difference between ff in try me and ff after install? Off to try some selected updates now to see if I can see it for myself. In previous installation I had several profiles and aliased ff with -safe-mode switch to simplify startup of most stable ff. Also found that ff startup in graphic mode worked better (but still without video) with all of the extensions disabled and all of the plugins set to "ask" and always denied ... I have SiS graphic card in SiS Motherboard for XP and ancient Hyundai ImageQuest QV770 monitor. I have Ubuntu 12.04.01 LTS 1 day after install with only the immediate upgrades requested to language pack (English UK). Using FR Alternative keyboard. Connected with domestic wifi network from Orange (FT) I really want to use Skype, but won't bother installing it (again) without video as I can do my sms on FB - whilst ff is not crashed ... Update ... Is something overflowing? I have just had to reboot in order to get ff to restart in any way shape or form - restart on crash form generates new crash form, etc. It was however a good half hour before it crashed so some improvement over conditions before disk corruption. I have now installed all of the critical updates (332 recommended updates still outstanding) which included some relating to ff. Still no video. Still crashing - especially when on Grepolis website. Since the re-install I have had a lovely 1024x768 screen, but after last ff crash and reboot I got a message about 'low graphics mode' and 'setting things myself'. I was not sufficiently tuned in at the time to take proper note - I have no doubt I shall see it again and shall report accordingly. I still have only laptop options for my screen and do not know how to rectify this. Spent a few days with ubuntu on a different, newer machine which has now suffered a graphics breakdown. Returned to this old one again, but with new flat screen Monitor. Found SIS drivers for my graphics BUT it is intended for Red Hat 7.2. I chose this over the version for 7.0 because I thought what the hell, I might not be able to do anything with either of them but this is the later one ... The file will not open with software manager - found a similar problem on Overclock but it has not helped me to install this driver. File name is sis_drv.o-410 and it is currently idling away in my Downloads folder ... I have tried the solution offered on another sis problem, but this shows that my xserver-xorg-video-sis driver is up to date. I am now at a loss as to how to proceed if I can't install the latest sis driver from sis ... Does nobody know how FF changes from "try-me" to "installed"? Any time I MUST have video I reboot from the disk again, but this is tedious! Also one of the things I mock most about MS is the constant rebooting ... UPDATE 10/6/2014 I have installed chromium-browser - worse, crashes even more often than ff.I have installed epiphany - better; Video works but not the associated soundtrack.FireFox is version 14.01 in 'try me' and version 29.0 from my install. Would it be useful to try to downgrade FireFox in order to get video?

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  • edited and reversed changes on .htaccess - site starts redirecting to .comindex.php/

    - by Aurigae
    Site is a Joomla 2.5 site. I wanted to add a non www to www redirect to the htaccess file, did so, then the redirection went mad, reversed but still the site redirects. When i click view site in admin panel, i get linked to http://domain.comindex.php/ The website is http://www.domain.com Visiting the website URL works without www, but once you click on projects it acts mad too. Projects is managed with joomshopping extension. EDIT: the redirect also happens when rewrite is deactivated in admin panel. ## # @package Joomla # @copyright Copyright (C) 2005 - 2012 Open Source Matters. All rights reserved. # @license GNU General Public License version 2 or later; see LICENSE.txt ## ## # READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE! # # The line just below this section: 'Options +FollowSymLinks' may cause problems # with some server configurations. It is required for use of mod_rewrite, but may already # be set by your server administrator in a way that dissallows changing it in # your .htaccess file. If using it causes your server to error out, comment it out (add # to # beginning of line), reload your site in your browser and test your sef url's. If they work, # it has been set by your server administrator and you do not need it set here. ## ## Can be commented out if causes errors, see notes above. Options +FollowSymLinks ## Mod_rewrite in use. RewriteEngine On ## Begin - Rewrite rules to block out some common exploits. # If you experience problems on your site block out the operations listed below # This attempts to block the most common type of exploit `attempts` to Joomla! # # Block out any script trying to base64_encode data within the URL. RewriteCond %{QUERY_STRING} base64_encode[^(]*\([^)]*\) [OR] # Block out any script that includes a <script> tag in URL. RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR] # Block out any script trying to set a PHP GLOBALS variable via URL. RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR] # Block out any script trying to modify a _REQUEST variable via URL. RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2}) # Return 403 Forbidden header and show the content of the root homepage RewriteRule .* index.php [F] # ## End - Rewrite rules to block out some common exploits. ## Begin - Custom redirects # # If you need to redirect some pages, or set a canonical non-www to # www redirect (or vice versa), place that code here. Ensure those # redirects use the correct RewriteRule syntax and the [R=301,L] flags. # ## End - Custom redirects ## # Uncomment following line if your webserver's URL # is not directly related to physical file paths. # Update Your Joomla! Directory (just / for root). ## # RewriteBase / ## Begin - Joomla! core SEF Section. # RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}] # # If the requested path and file is not /index.php and the request # has not already been internally rewritten to the index.php script RewriteCond %{REQUEST_URI} !^/index\.php # and the request is for something within the component folder, # or for the site root, or for an extensionless URL, or the # requested URL ends with one of the listed extensions RewriteCond %{REQUEST_URI} /component/|(/[^.]*|\.(php|html?|feed|pdf|vcf|raw))$ [NC] # and the requested path and file doesn't directly match a physical file RewriteCond %{REQUEST_FILENAME} !-f # and the requested path and file doesn't directly match a physical folder RewriteCond %{REQUEST_FILENAME} !-d # internally rewrite the request to the index.php script RewriteRule .* index.php [L] # ## End - Joomla! core SEF Section. Redirect 301 /index.html /index.php Redirect 301 /services /project Redirect 301 /projects/projects.html /project Redirect 301 /projects/project1.html /project Redirect 301 /projects/project2.html /project Redirect 301 /projects /project Redirect 301 /keypersonnel.html /about-agrin/keystaff Redirect 301 /cooperation.htm /about-agrin/intcoop Redirect 301 /member.html /about-agrin/memberships Redirect 301 /contact.html /contacts Redirect 301 /hr.htm /jobs Redirect 301 /index.php/404 /index.php

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  • JEP 124: Enhance the Certificate Revocation-Checking API

    - by smullan
    Revocation checking is the mechanism to determine the revocation status of a certificate. If it is revoked, it is considered invalid and should not be used. Currently as of JDK 7, the PKIX implementation of java.security.cert.CertPathValidator  includes a revocation checking implementation that supports both OCSP and CRLs, the two main methods of checking revocation. However, there are very few options that allow you to configure the behavior. You can always implement your own revocation checker, but that's a lot of work. JEP 124 (Enhance the Certificate Revocation-Checking API) is one of the 11 new security features in JDK 8. This feature enhances the java.security.cert API to support various revocation settings such as best-effort checking, end-entity certificate checking, and mechanism-specific options and parameters. Let's describe each of these in more detail and show some examples. The features are provided through a new class named PKIXRevocationChecker. A PKIXRevocationChecker instance is returned by a PKIX CertPathValidator as follows: CertPathValidator cpv = CertPathValidator.getInstance("PKIX"); PKIXRevocationChecker prc = (PKIXRevocationChecker)cpv.getRevocationChecker(); You can now set various revocation options by calling different methods of the returned PKIXRevocationChecker object. For example, the best-effort option (called soft-fail) allows the revocation check to succeed if the status cannot be obtained due to a network connection failure or an overloaded server. It is enabled as follows: prc.setOptions(Enum.setOf(Option.SOFT_FAIL)); When the SOFT_FAIL option is specified, you can still obtain any exceptions that may have been thrown due to network issues. This can be useful if you want to log this information or treat it as a warning. You can obtain these exceptions by calling the getSoftFailExceptions method: List<CertPathValidatorException> exceptions = prc.getSoftFailExceptions(); Another new option called ONLY_END_ENTITY allows you to only check the revocation status of the end-entity certificate. This can improve performance, but you should be careful using this option, as the revocation status of CA certificates will not be checked. To set more than one option, simply specify them together, for example: prc.setOptions(Enum.setOf(Option.SOFT_FAIL, Option.ONLY_END_ENTITY)); By default, PKIXRevocationChecker will try to check the revocation status of a certificate using OCSP first, and then CRLs as a fallback. However, you can switch the order using the PREFER_CRLS option, or disable the fallback altogether using the NO_FALLBACK option. For example, here is how you would only use CRLs to check the revocation status: prc.setOptions(Enum.setOf(Option.PREFER_CRLS, Option.NO_FALLBACK)); There are also a number of other useful methods which allow you to specify various options such as the OCSP responder URI, the trusted OCSP responder certificate, and OCSP request extensions. However, one of the most useful features is the ability to specify a cached OCSP response with the setOCSPResponse method. This can be quite useful if the OCSPResponse has already been obtained, for example in a protocol that uses OCSP stapling. After you have set all of your preferred options, you must add the PKIXRevocationChecker to your PKIXParameters object as one of your custom CertPathCheckers before you validate the certificate chain, as follows: PKIXParameters params = new PKIXParameters(keystore); params.addCertPathChecker(prc); CertPathValidatorResult result = cpv.validate(path, params); Early access binaries of JDK 8 can be downloaded from http://jdk8.java.net/download.html

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  • Custom Text and Binary Payloads using WebSocket (TOTD #186)

    - by arungupta
    TOTD #185 explained how to process text and binary payloads in a WebSocket endpoint. In summary, a text payload may be received as public void receiveTextMessage(String message) {    . . . } And binary payload may be received as: public void recieveBinaryMessage(ByteBuffer message) {    . . .} As you realize, both of these methods receive the text and binary data in raw format. However you may like to receive and send the data using a POJO. This marshaling and unmarshaling can be done in the method implementation but JSR 356 API provides a cleaner way. For encoding and decoding text payload into POJO, Decoder.Text (for inbound payload) and Encoder.Text (for outbound payload) interfaces need to be implemented. A sample implementation below shows how text payload consisting of JSON structures can be encoded and decoded. public class MyMessage implements Decoder.Text<MyMessage>, Encoder.Text<MyMessage> {     private JsonObject jsonObject;    @Override    public MyMessage decode(String string) throws DecodeException {        this.jsonObject = new JsonReader(new StringReader(string)).readObject();               return this;    }     @Override    public boolean willDecode(String string) {        return true;    }     @Override    public String encode(MyMessage myMessage) throws EncodeException {        return myMessage.jsonObject.toString();    } public JsonObject getObject() { return jsonObject; }} In this implementation, the decode method decodes incoming text payload to MyMessage, the encode method encodes MyMessage for the outgoing text payload, and the willDecode method returns true or false if the message can be decoded. The encoder and decoder implementation classes need to be specified in the WebSocket endpoint as: @WebSocketEndpoint(value="/endpoint", encoders={MyMessage.class}, decoders={MyMessage.class}) public class MyEndpoint { public MyMessage receiveMessage(MyMessage message) { . . . } } Notice the updated method signature where the application is working with MyMessage instead of the raw string. Note that the encoder and decoder implementations just illustrate the point and provide no validation or exception handling. Similarly Encooder.Binary and Decoder.Binary interfaces need to be implemented for encoding and decoding binary payload. Here are some references for you: JSR 356: Java API for WebSocket - Specification (Early Draft) and Implementation (already integrated in GlassFish 4 promoted builds) TOTD #183 - Getting Started with WebSocket in GlassFish TOTD #184 - Logging WebSocket Frames using Chrome Developer Tools, Net-internals and Wireshark TOTD #185: Processing Text and Binary (Blob, ArrayBuffer, ArrayBufferView) Payload in WebSocket Subsequent blogs will discuss the following topics (not necessary in that order) ... Error handling Interface-driven WebSocket endpoint Java client API Client and Server configuration Security Subprotocols Extensions Other topics from the API

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  • Why is the framerate (fps) capped at 60?

    - by dennmat
    ISSUE I recently moved a project from my laptop to my desktop(machine info below). On my laptop the exact same code displays the fps(and ms/f) correctly. On my desktop it does not. What I mean by this is on the laptop it will display 300 fps(for example) where on my desktop it will show only up to 60. If I add 100 objects to the game on the laptop I'll see my frame rate drop accordingly; the same test on the desktop results in no change and the frames stay at 60. It takes a lot(~300) entities before I'll see a frame drop on the desktop, then it will descend. It seems as though its "theoretical" frames would be 400 or 500 but will never actually get to that and only do 60 until there's too much to handle at 60. This 60 frame cap is coming from no where. I'm not doing any frame limiting myself. It seems like something external is limiting my loop iterations on the desktop, but for the last couple days I've been scratching my head trying to figure out how to debug this. SETUPS Desktop: Visual Studio Express 2012 Windows 7 Ultimate 64-bit Laptop: Visual Studio Express 2010 Windows 7 Ultimate 64-bit The libraries(allegro, box2d) are the same versions on both setups. CODE Main Loop: while(!abort) { frameTime = al_get_time(); if (frameTime - lastTime >= 1.0) { lastFps = fps/(frameTime - lastTime); lastTime = frameTime; avgMspf = cumMspf/fps; cumMspf = 0.0; fps = 0; } /** DRAWING/UPDATE CODE **/ fps++; cumMspf += al_get_time() - frameTime; } Note: There is no blocking code in the loop at any point. Where I'm at My understanding of al_get_time() is that it can return different resolutions depending on the system. However the resolution is never worse than seconds, and the double is represented as [seconds].[finer-resolution] and seeing as I'm only checking for a whole second al_get_time() shouldn't be responsible. My project settings and compiler options are the same. And I promise its the same code on both machines. My googling really didn't help me much, and although technically it's not that big of a deal. I'd really like to figure this out or perhaps have it explained, whichever comes first. Even just an idea of how to go about figuring out possible causes, because I'm out of ideas. Any help at all is greatly appreciated. EDIT: Thanks All. For any others that find this to disable vSync(windows only) in opengl: First get "wglext.h". It's all over the web. Then you can use a tool like GLee or just write your own quick extensions manager like: bool WGLExtensionSupported(const char *extension_name) { PFNWGLGETEXTENSIONSSTRINGEXTPROC _wglGetExtensionsStringEXT = NULL; _wglGetExtensionsStringEXT = (PFNWGLGETEXTENSIONSSTRINGEXTPROC) wglGetProcAddress("wglGetExtensionsStringEXT"); if (strstr(_wglGetExtensionsStringEXT(), extension_name) == NULL) { return false; } return true; } and then create and setup your function pointers: PFNWGLSWAPINTERVALEXTPROC wglSwapIntervalEXT = NULL; PFNWGLGETSWAPINTERVALEXTPROC wglGetSwapIntervalEXT = NULL; if (WGLExtensionSupported("WGL_EXT_swap_control")) { // Extension is supported, init pointers. wglSwapIntervalEXT = (PFNWGLSWAPINTERVALEXTPROC) wglGetProcAddress("wglSwapIntervalEXT"); // this is another function from WGL_EXT_swap_control extension wglGetSwapIntervalEXT = (PFNWGLGETSWAPINTERVALEXTPROC) wglGetProcAddress("wglGetSwapIntervalEXT"); } Then just call wglSwapIntervalEXT(0) to disable vSync and 1 to enable vSync. I found the reason this is windows only is that openGl actually doesn't deal with anything other than rendering it leaves the rest up to the OS and Hardware. Thanks everyone saved me a lot of time!

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  • The long road to bug-free software

    - by Tony Davis
    The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

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  • Taking too long to get skills for entry level programmer position [closed]

    - by greenonion
    I don't have the skills for an entry level position as a .Net programmer. I am trying to learn what I need but there is too much to learn and too little time. What can I do? About two months ago, I went to a job interview for an entry level C# .Net programming/consultant position in NYC. When I heard back from them, they told me that the knowledge gap between what I knew and what they needed me to know was too big and I might have been a better fit if I had 6 months of experience. This was the first interview that I went on since graduating college. before the interview, I read a book on visual C#. Turns out it wasn't a very good book and I was missing a lot of key areas of knowledge such as ADO.net SQL (I had learned some LINQ) A little bit about how memory is handled Multiple threaded programming, etc. Because the book wasn't very good, the stuff I did know, I didn't know very well. I felt crushed. I've applied for jobs to gain experience but when recruiters hear that I have no experience they lose interest. I figured that I can at least work on my knowledge. Since then, I read "SQL Essentials" to cover the SQL bit and I found a pretty awesome book that is good enough to clear up what's hazy in my mind and covers almost all of the extra topics. The book is "C# 4.0: The Complete Reference" by Herbert Schildt. I'm even learning a lot about the topics I was familiar with. For a month now I've been working my way through this beast of a book. However, gaining the knowledge I need is taking too long. I can't hold off not having a full-time job much longer. I'm not stupid and I'm studying constantly pouring through the book, asking questions on stackoverflow, referencing the C# specification, etc. I have made great progress but there is just too much ground to cover. I'm on chapter 12 which is about a 3rd through the book. To get an idea of what I know vs don't know, the table of contents is on amazon: http://www.amazon.com/C-4-0-The-Complete-Reference/dp/007174116X How on earth can someone know enough to function as a programmer in the real world? Can I try for a job in academia? Will I have time to finish learning the rest of the C# language or am I just un-hireable?

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  • High Resolution Timeouts

    - by user12607257
    The default resolution of application timers and timeouts is now 1 msec in Solaris 11.1, down from 10 msec in previous releases. This improves out-of-the-box performance of polling and event based applications, such as ticker applications, and even the Oracle rdbms log writer. More on that in a moment. As a simple example, the poll() system call takes a timeout argument in units of msec: System Calls poll(2) NAME poll - input/output multiplexing SYNOPSIS int poll(struct pollfd fds[], nfds_t nfds, int timeout); In Solaris 11, a call to poll(NULL,0,1) returns in 10 msec, because even though a 1 msec interval is requested, the implementation rounds to the system clock resolution of 10 msec. In Solaris 11.1, this call returns in 1 msec. In specification lawyer terms, the resolution of CLOCK_REALTIME, introduced by POSIX.1b real time extensions, is now 1 msec. The function clock_getres(CLOCK_REALTIME,&res) returns 1 msec, and any library calls whose man page explicitly mention CLOCK_REALTIME, such as nanosleep(), are subject to the new resolution. Additionally, many legacy functions that pre-date POSIX.1b and do not explicitly mention a clock domain, such as poll(), are subject to the new resolution. Here is a fairly comprehensive list: nanosleep pthread_mutex_timedlock pthread_mutex_reltimedlock_np pthread_rwlock_timedrdlock pthread_rwlock_reltimedrdlock_np pthread_rwlock_timedwrlock pthread_rwlock_reltimedwrlock_np mq_timedreceive mq_reltimedreceive_np mq_timedsend mq_reltimedsend_np sem_timedwait sem_reltimedwait_np poll select pselect _lwp_cond_timedwait _lwp_cond_reltimedwait semtimedop sigtimedwait aiowait aio_waitn aio_suspend port_get port_getn cond_timedwait cond_reltimedwait setitimer (ITIMER_REAL) misc rpc calls, misc ldap calls This change in resolution was made feasible because we made the implementation of timeouts more efficient a few years back when we re-architected the callout subsystem of Solaris. Previously, timeouts were tested and expired by the kernel's clock thread which ran 100 times per second, yielding a resolution of 10 msec. This did not scale, as timeouts could be posted by every CPU, but were expired by only a single thread. The resolution could be changed by setting hires_tick=1 in /etc/system, but this caused the clock thread to run at 1000 Hz, which made the potential scalability problem worse. Given enough CPUs posting enough timeouts, the clock thread could be a performance bottleneck. We fixed that by re-implementing the timeout as a per-CPU timer interrupt (using the cyclic subsystem, for those familiar with Solaris internals). This decoupled the clock thread frequency from timeout resolution, and allowed us to improve default timeout resolution without adding CPU overhead in the clock thread. Here are some exceptions for which the default resolution is still 10 msec. The thread scheduler's time quantum is 10 msec by default, because preemption is driven by the clock thread (plus helper threads for scalability). See for example dispadmin, priocntl, fx_dptbl, rt_dptbl, and ts_dptbl. This may be changed using hires_tick. The resolution of the clock_t data type, primarily used in DDI functions, is 10 msec. It may be changed using hires_tick. These functions are only used by developers writing kernel modules. A few functions that pre-date POSIX CLOCK_REALTIME mention _SC_CLK_TCK, CLK_TCK, "system clock", or no clock domain. These functions are still driven by the clock thread, and their resolution is 10 msec. They include alarm, pcsample, times, clock, and setitimer for ITIMER_VIRTUAL and ITIMER_PROF. Their resolution may be changed using hires_tick. Now back to the database. How does this help the Oracle log writer? Foreground processes post a redo record to the log writer, which releases them after the redo has committed. When a large number of foregrounds are waiting, the release step can slow down the log writer, so under heavy load, the foregrounds switch to a mode where they poll for completion. This scales better because every foreground can poll independently, but at the cost of waiting the minimum polling interval. That was 10 msec, but is now 1 msec in Solaris 11.1, so the foregrounds process transactions faster under load. Pretty cool.

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  • ????????????????? Oracle Solaris ??? - Solaris 11 ????

    - by kazun
    ???????????????? OS ????????????????????? 20 ??????????????????? Solaris?????????????????????? OS????????????????????????Solaris ???????????????????? ??????Solaris ?????????????? 4 ????????????????????? Oracle Solaris 11 ??????????????? [????????????]???? ?(????????????? ???)???? ?(??????????????)???? ?(????????)???? ?(?????????????????)(50??) Oracle Solaris 11 ??????? ???:Oracle Solaris 11??????? Solaris ??????????????????????????????????????????????Oracle Solaris 10 ?????????????????Oracle Solaris 11 ???Oracle Solaris ???????????????????????????????????????????????????????????????????????????????????Oracle Solaris ??????????????????????????Oracle Solaris ????????????????????????????????????????? ??:??????????????????????????????????????????????????????????????????????????????????Oracle Solaris 11 ????????????????????????????????????????????????????????????????????????????????????????????????Oracle Solaris 11 ????????????? ???:Oracle Solaris 11 ????????????????????????????????????????????????????????????Oracle Solaris ??????????????????????Solaris ????????????????????????Oracle Solaris 11 ?????????????????????????????????????????????????????????????????????? Oracle Solaris 11 ??????????????? ??:???????????????????ZFS?????????????Oracle Solaris ???????????????????????????????????????IPS???????????????????????? ??:?????????????????????? OS ??????????????????????????????????????????????????????????????????? OS ????? Oracle Solaris 11 ??? ??:????????????????????????????????????????????????? Oracle Solaris 11 ???????????????????????????????????????????????????????? ??:????????????????????Solaris Trusted Extensions ? Solaris ????????????Privilege ????????????????????????????????Solaris 10 ???????????????????? ??:UNIX ?????????????????????????????????????Oracle Solaris 11 ??????????????????????????????????????????????????ZFS ??????????????????????????????????????????????????Oracle Solaris ?????????????????????????????????? ???:Oracle Solaris ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????Oracle Solaris 11 ??????????????????????????????????????????????????? ?????????????Oracle Solaris 11 ??:Oracle Solaris ?????????????????????????????????????????????????????????????????? ZFS ?????????????????????????????????????????????? ??:?????????????????????????????????????????????????????????????????????Oracle Solaris ??????????????????????? ??:DTrace ????????????????????????????????????????????????????????????? ??:???????????????????????????????????????????????????????????????????????????????????????? ???:?????????????????????????????????????????????????????????????????????????Solaris ???????????????????????????????????????????????????????????????????????????? ??:?????????????????? Solaris 10 ?????????????????????????????????????? ???:ISV ??????????????????????????????? ????????????????? T4 ??????????????? T ?????? 5 ???????????????????????????????????? CPU ?????????????????? OS ? Solaris ??????????????????????????????????????????????? ??:???????????????? OS ???? Solaris ???????????????????????????????????????????????????? Oracle Solaris ????????? ??:???????????????????????????????????????????????????????????????????????????????????????? ZFS ?????????????????????????ZFS ??????????????????????????????????????? ???:Linux ??????????????????????????Solaris 11 ?????????????????????? GNU ????????????????????????????Solaris ?????????(Oracle Solaris Studio)????????????? Oracle Solaris Studio ?Linux??????????????Linux ??????????? Solaris ????????????????Linux ? Oracle Solaris Studio ?????????????????????????? Solaris ??????????????????? ??:??????????????????????????????????????????????????????????????????????????????????????????????????????????????????BCP(??????)??????????????????? ??:???????? Solaris 11 ?????? IA Server ?????????????????????????????????????????????…???????????Windows ????????????????????? Oracle Virtual Box ????????? Oracle Solaris 11 ??????????? ??:???Oracle Solaris ????????(?)??????????????ZFS???DTrace?????????????????????????????????????Solaris ?????????????????????????????????????????????????????????????????????????????Solaris ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ??:??? 3 ??????????????????????????????????????Oracle Solaris 11 ???????????? ??:???????????????????? OS ??????????????????????????Oracle Solaris 11 ???????????????????????????????????????????????????????????????? ???:???????????? Solaris ???????????????Solaris 10 ???? 6 ??????????????????????????????????Oracle Solaris ?????????????????????????????? ?????? Oracle Solaris 10 Oracle Solaris 11

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  • A network-related or instance-specific error occurred while establishing a connection to SQL Server

    - by sf
    Hi, I'm getting the following error when trying to load an Asp.NET MVC App on IIS 7 with Sql Server 2008 Express. The App uses Linq to SQL. A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) I've done some searching and all answers point to enabling TCP connections in Sql Server Configuration which I have done to no avail. The connection string I am using is: Server=SERVERNAME\SQLEXPRESS;Database=DBName;Integrated Security=true The catch. I have another app that already could talk to the Sql Server just fine. Even before playing around with the Sql Server Configuration Settings. The other app uses the following connectionstring: Data Source=SERVERNAME\SQLEXPRESS;Initial Catalog=OtherDbName;Integrated Security=True;Persist Security Info=False;Connect Timeout=120 I've tried this connectionstring on the app that isn't working and it still doesn't work. Please help. I think i'm about to go crazy

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  • Whats the easiest route to trying out mono 2.6?

    - by E J
    We have several web applications built on Microsoft technologies (asp.net+mvc framework, built using VS2008, MS SQL Server). I have recently be playing with Ubuntu (9.10), installed using Wubi, and wanted to see if I can get our apps running on a foss software stack. I have got the hang of the very basics of Postgresql and I have read that there is some support for Linq to SQL in mono (as of 2.6) as well as asp.net/MVC. However I am unsure how to go about getting Mono 2.6 up and running. Here is what I have discovered so far: Ubuntu is not meant for the 'cutting edge' it is designed to be stable hence, it sometimes takes a release cycle or two for new software to make it to the repositories Mono is already installed by default, but it is likely to stay at version 2.4 for at least the 10.4 release You can install paralell environments of Mono, if you know what your doing. I have had a go at setting up parallel environments, but haven't had any luck yet. (And TBH I am not certain that that will do what I think it's gonna do). (tl;dr start here) Is there a distribution of Linux similar enough to Ubuntu, that I wouldn't have to start the learning curve all over again, but that will let me install Mono 2.6, Postgresql, (and possibly mono-develop 2.4)? Or should I persist with Ubuntu?

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