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• Adding an Admin user to an ASP.NET MVC 4 application using a single drop-in file

  - by Jon Galloway

  I'm working on an ASP.NET MVC 4 tutorial and wanted to set it up so just dropping a file in App_Start would create a user named "Owner" and assign them to the "Administrator" role (more explanation at the end if you're interested). There are reasons why this wouldn't fit into most application scenarios: It's not efficient, as it checks for (and creates, if necessary) the user every time the app starts up The username, password, and role name are hardcoded in the app (although they could be pulled from config) Automatically creating an administrative account in code (without user interaction) could lead to obvious security issues if the user isn't informed However, with some modifications it might be more broadly useful - e.g. creating a test user with limited privileges, ensuring a required account isn't accidentally deleted, or - as in my case - setting up an account for demonstration or tutorial purposes. Challenge #1: Running on startup without requiring the user to install or configure anything I wanted to see if this could be done just by having the user drop a file into the App_Start folder and go. No copying code into Global.asax.cs, no installing addition NuGet packages, etc. That may not be the best approach - perhaps a NuGet package with a dependency on WebActivator would be better - but I wanted to see if this was possible and see if it offered the best experience. Fortunately ASP.NET 4 and later provide a PreApplicationStartMethod attribute which allows you to register a method which will run when the application starts up. You drop this attribute in your application and give it two parameters: a method name and the type that contains it. I created a static class named PreApplicationTasks with a static method named, then dropped this attribute in it: [assembly: PreApplicationStartMethod(typeof(PreApplicationTasks), "Initializer")] That's it. One small gotcha: the namespace can be a problem with assembly attributes. I decided my class didn't need a namespace. Challenge #2: Only one PreApplicationStartMethod per assembly In .NET 4, the PreApplicationStartMethod is marked as AllMultiple=false, so you can only have one PreApplicationStartMethod per assembly. This was fixed in .NET 4.5, as noted by Jon Skeet, so you can have as many PreApplicationStartMethods as you want (allowing you to keep your users waiting for the application to start indefinitely!). The WebActivator NuGet package solves the multiple instance problem if you're in .NET 4 - it registers as a PreApplicationStartMethod, then calls any methods you've indicated using [assembly: WebActivator.PreApplicationStartMethod(type, method)]. David Ebbo blogged about that here:  Light up your NuGets with startup code and WebActivator. In my scenario (bootstrapping a beginner level tutorial) I decided not to worry about this and stick with PreApplicationStartMethod. Challenge #3: PreApplicationStartMethod kicks in before configuration has been read This is by design, as Phil explains. It allows you to make changes that need to happen very early in the pipeline, well before Application_Start. That's fine in some cases, but it caused me problems when trying to add users, since the Membership Provider configuration hadn't yet been read - I got an exception stating that "Default Membership Provider could not be found." The solution here is to run code that requires configuration in a PostApplicationStart method. But how to do that? Challenge #4: Getting PostApplicationStartMethod without requiring WebActivator The WebActivator NuGet package, among other things, provides a PostApplicationStartMethod attribute. That's generally how I'd recommend running code that needs to happen after Application_Start: [assembly: WebActivator.PostApplicationStartMethod(typeof(TestLibrary.MyStartupCode), "CallMeAfterAppStart")] This works well, but I wanted to see if this would be possible without WebActivator. Hmm. Well, wait a minute - WebActivator works in .NET 4, so clearly it's registering and calling PostApplicationStartup tasks somehow. Off to the source code! Sure enough, there's even a handy comment in ActivationManager.cs which shows where PostApplicationStartup tasks are being registered: public static void Run() { if (!_hasInited) { RunPreStartMethods(); // Register our module to handle any Post Start methods. But outside of ASP.NET, just run them now if (HostingEnvironment.IsHosted) { Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(StartMethodCallingModule)); } else { RunPostStartMethods(); } _hasInited = true; } } Excellent. Hey, that DynamicModuleUtility seems familiar... Sure enough, K. Scott Allen mentioned it on his blog last year. This is really slick - a PreApplicationStartMethod can register a new HttpModule in code. Modules are run right after application startup, so that's a perfect time to do any startup stuff that requires configuration to be read. As K. Scott says, it's this easy: using System; using System.Web; using Microsoft.Web.Infrastructure.DynamicModuleHelper; [assembly:PreApplicationStartMethod(typeof(MyAppStart), "Start")] public class CoolModule : IHttpModule { // implementation not important // imagine something cool here } public static class MyAppStart { public static void Start() { DynamicModuleUtility.RegisterModule(typeof(CoolModule)); } } Challenge #5: Cooperating with SimpleMembership The ASP.NET MVC Internet template includes SimpleMembership. SimpleMembership is a big improvement over traditional ASP.NET Membership. For one thing, rather than forcing a database schema, it can work with your database schema. In the MVC 4 Internet template case, it uses Entity Framework Code First to define the user model. SimpleMembership bootstrap includes a call to InitializeDatabaseConnection, and I want to play nice with that. There's a new [InitializeSimpleMembership] attribute on the AccountController, which calls \Filters\InitializeSimpleMembershipAttribute.cs::OnActionExecuting(). That comment in that method that says "Ensure ASP.NET Simple Membership is initialized only once per app start" which sounds like good advice. I figured the best thing would be to call that directly: new Mvc4SampleApplication.Filters.InitializeSimpleMembershipAttribute().OnActionExecuting(null); I'm not 100% happy with this - in fact, it's my least favorite part of this solution. There are two problems - first, directly calling a method on a filter, while legal, seems odd. Worse, though, the Filter lives in the application's namespace, which means that this code no longer works well as a generic drop-in. The simplest workaround would be to duplicate the relevant SimpleMembership initialization code into my startup code, but I'd rather not. I'm interested in your suggestions here. Challenge #6: Module Init methods are called more than once When debugging, I noticed (and remembered) that the Init method may be called more than once per page request - it's run once per instance in the app pool, and an individual page request can cause multiple resource requests to the server. While SimpleMembership does have internal checks to prevent duplicate user or role entries, I'd rather not cause or handle those exceptions. So here's the standard single-use lock in the Module's init method: void IHttpModule.Init(HttpApplication context) { lock (lockObject) { if (!initialized) { //Do stuff } initialized = true; } } Putting it all together With all of that out of the way, here's the code I came up with: using Mvc4SampleApplication.Filters; using System.Web; using System.Web.Security; using WebMatrix.WebData; [assembly: PreApplicationStartMethod(typeof(PreApplicationTasks), "Initializer")] public static class PreApplicationTasks { public static void Initializer() { Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility .RegisterModule(typeof(UserInitializationModule)); } } public class UserInitializationModule : IHttpModule { private static bool initialized; private static object lockObject = new object(); private const string _username = "Owner"; private const string _password = "p@ssword123"; private const string _role = "Administrator"; void IHttpModule.Init(HttpApplication context) { lock (lockObject) { if (!initialized) { new InitializeSimpleMembershipAttribute().OnActionExecuting(null); if (!WebSecurity.UserExists(_username)) WebSecurity.CreateUserAndAccount(_username, _password); if (!Roles.RoleExists(_role)) Roles.CreateRole(_role); if (!Roles.IsUserInRole(_username, _role)) Roles.AddUserToRole(_username, _role); } initialized = true; } } void IHttpModule.Dispose() { } } The Verdict: Is this a good thing? Maybe. I think you'll agree that the journey was undoubtedly worthwhile, as it took us through some of the finer points of hooking into application startup, integrating with membership, and understanding why the WebActivator NuGet package is so useful Will I use this in the tutorial? I'm leaning towards no - I think a NuGet package with a dependency on WebActivator might work better: It's a little more clear what's going on Installing a NuGet package might be a little less error prone than copying a file A novice user could uninstall the package when complete It's a good introduction to NuGet, which is a good thing for beginners to see This code either requires either duplicating a little code from that filter or modifying the file to use the namespace Honestly I'm undecided at this point, but I'm glad that I can weigh the options. If you're interested: Why are you doing this? I'm updating the MVC Music Store tutorial to ASP.NET MVC 4, taking advantage of a lot of new ASP.NET MVC 4 features and trying to simplify areas that are giving people trouble. One change that addresses both needs us using the new OAuth support for membership as much as possible - it's a great new feature from an application perspective, and we get a fair amount of beginners struggling with setting up membership on a variety of database and development setups, which is a distraction from the focus of the tutorial - learning ASP.NET MVC. Side note: Thanks to some great help from Rick Anderson, we had a draft of the tutorial that was looking pretty good earlier this summer, but there were enough changes in ASP.NET MVC 4 all the way up to RTM that there's still some work to be done. It's high priority and should be out very soon. The one issue I ran into with OAuth is that we still need an Administrative user who can edit the store's inventory. I thought about a number of solutions for that - making the first user to register the admin, or the first user to use the username "Administrator" is assigned to the Administrator role - but they both ended up requiring extra code; also, I worried that people would use that code without understanding it or thinking about whether it was a good fit.

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• C#/.NET Little Wonders: The Predicate, Comparison, and Converter Generic Delegates

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. In the last three weeks, we examined the Action family of delegates (and delegates in general), the Func family of delegates, and the EventHandler family of delegates and how they can be used to support generic, reusable algorithms and classes. This week I will be completing my series on the generic delegates in the .NET Framework with a discussion of three more, somewhat less used, generic delegates: Predicate<T>, Comparison<T>, and Converter<TInput, TOutput>. These are older generic delegates that were introduced in .NET 2.0, mostly for use in the Array and List<T> classes.  Though older, it’s good to have an understanding of them and their intended purpose.  In addition, you can feel free to use them yourself, though obviously you can also use the equivalents from the Func family of delegates instead. Predicate<T> – delegate for determining matches The Predicate<T> delegate was a very early delegate developed in the .NET 2.0 Framework to determine if an item was a match for some condition in a List<T> or T[].  The methods that tend to use the Predicate<T> include: Find(), FindAll(), FindLast() Uses the Predicate<T> delegate to finds items, in a list/array of type T, that matches the given predicate. FindIndex(), FindLastIndex() Uses the Predicate<T> delegate to find the index of an item, of in a list/array of type T, that matches the given predicate. The signature of the Predicate<T> delegate (ignoring variance for the moment) is: 1: public delegate bool Predicate<T>(T obj); So, this is a delegate type that supports any method taking an item of type T and returning bool.  In addition, there is a semantic understanding that this predicate is supposed to be examining the item supplied to see if it matches a given criteria. 1: // finds first even number (2) 2: var firstEven = Array.Find(numbers, n => (n % 2) == 0); 3:  4: // finds all odd numbers (1, 3, 5, 7, 9) 5: var allEvens = Array.FindAll(numbers, n => (n % 2) == 1); 6:  7: // find index of first multiple of 5 (4) 8: var firstFiveMultiplePos = Array.FindIndex(numbers, n => (n % 5) == 0); This delegate has typically been succeeded in LINQ by the more general Func family, so that Predicate<T> and Func<T, bool> are logically identical.  Strictly speaking, though, they are different types, so a delegate reference of type Predicate<T> cannot be directly assigned to a delegate reference of type Func<T, bool>, though the same method can be assigned to both. 1: // SUCCESS: the same lambda can be assigned to either 2: Predicate<DateTime> isSameDayPred = dt => dt.Date == DateTime.Today; 3: Func<DateTime, bool> isSameDayFunc = dt => dt.Date == DateTime.Today; 4:  5: // ERROR: once they are assigned to a delegate type, they are strongly 6: // typed and cannot be directly assigned to other delegate types. 7: isSameDayPred = isSameDayFunc; When you assign a method to a delegate, all that is required is that the signature matches.  This is why the same method can be assigned to either delegate type since their signatures are the same.  However, once the method has been assigned to a delegate type, it is now a strongly-typed reference to that delegate type, and it cannot be assigned to a different delegate type (beyond the bounds of variance depending on Framework version, of course). Comparison<T> – delegate for determining order Just as the Predicate<T> generic delegate was birthed to give Array and List<T> the ability to perform type-safe matching, the Comparison<T> was birthed to give them the ability to perform type-safe ordering. The Comparison<T> is used in Array and List<T> for: Sort() A form of the Sort() method that takes a comparison delegate; this is an alternate way to custom sort a list/array from having to define custom IComparer<T> classes. The signature for the Comparison<T> delegate looks like (without variance): 1: public delegate int Comparison<T>(T lhs, T rhs); The goal of this delegate is to compare the left-hand-side to the right-hand-side and return a negative number if the lhs < rhs, zero if they are equal, and a positive number if the lhs > rhs.  Generally speaking, null is considered to be the smallest value of any reference type, so null should always be less than non-null, and two null values should be considered equal. In most sort/ordering methods, you must specify an IComparer<T> if you want to do custom sorting/ordering.  The Array and List<T> types, however, also allow for an alternative Comparison<T> delegate to be used instead, essentially, this lets you perform the custom sort without having to have the custom IComparer<T> class defined. It should be noted, however, that the LINQ OrderBy(), and ThenBy() family of methods do not support the Comparison<T> delegate (though one could easily add their own extension methods to create one, or create an IComparer() factory class that generates one from a Comparison<T>). So, given this delegate, we could use it to perform easy sorts on an Array or List<T> based on custom fields.  Say for example we have a data class called Employee with some basic employee information: 1: public sealed class Employee 2: { 3: public string Name { get; set; } 4: public int Id { get; set; } 5: public double Salary { get; set; } 6: } And say we had a List<Employee> that contained data, such as: 1: var employees = new List<Employee> 2: { 3: new Employee { Name = "John Smith", Id = 2, Salary = 37000.0 }, 4: new Employee { Name = "Jane Doe", Id = 1, Salary = 57000.0 }, 5: new Employee { Name = "John Doe", Id = 5, Salary = 60000.0 }, 6: new Employee { Name = "Jane Smith", Id = 3, Salary = 59000.0 } 7: }; Now, using the Comparison<T> delegate form of Sort() on the List<Employee>, we can sort our list many ways: 1: // sort based on employee ID 2: employees.Sort((lhs, rhs) => Comparer<int>.Default.Compare(lhs.Id, rhs.Id)); 3:  4: // sort based on employee name 5: employees.Sort((lhs, rhs) => string.Compare(lhs.Name, rhs.Name)); 6:  7: // sort based on salary, descending (note switched lhs/rhs order for descending) 8: employees.Sort((lhs, rhs) => Comparer<double>.Default.Compare(rhs.Salary, lhs.Salary)); So again, you could use this older delegate, which has a lot of logical meaning to it’s name, or use a generic delegate such as Func<T, T, int> to implement the same sort of behavior.  All this said, one of the reasons, in my opinion, that Comparison<T> isn’t used too often is that it tends to need complex lambdas, and the LINQ ability to order based on projections is much easier to use, though the Array and List<T> sorts tend to be more efficient if you want to perform in-place ordering. Converter<TInput, TOutput> – delegate to convert elements The Converter<TInput, TOutput> delegate is used by the Array and List<T> delegate to specify how to convert elements from an array/list of one type (TInput) to another type (TOutput).  It is used in an array/list for: ConvertAll() Converts all elements from a List<TInput> / TInput[] to a new List<TOutput> / TOutput[]. The delegate signature for Converter<TInput, TOutput> is very straightforward (ignoring variance): 1: public delegate TOutput Converter<TInput, TOutput>(TInput input); So, this delegate’s job is to taken an input item (of type TInput) and convert it to a return result (of type TOutput).  Again, this is logically equivalent to a newer Func delegate with a signature of Func<TInput, TOutput>.  In fact, the latter is how the LINQ conversion methods are defined. So, we could use the ConvertAll() syntax to convert a List<T> or T[] to different types, such as: 1: // get a list of just employee IDs 2: var empIds = employees.ConvertAll(emp => emp.Id); 3:  4: // get a list of all emp salaries, as int instead of double: 5: var empSalaries = employees.ConvertAll(emp => (int)emp.Salary); Note that the expressions above are logically equivalent to using LINQ’s Select() method, which gives you a lot more power: 1: // get a list of just employee IDs 2: var empIds = employees.Select(emp => emp.Id).ToList(); 3:  4: // get a list of all emp salaries, as int instead of double: 5: var empSalaries = employees.Select(emp => (int)emp.Salary).ToList(); The only difference with using LINQ is that many of the methods (including Select()) are deferred execution, which means that often times they will not perform the conversion for an item until it is requested.  This has both pros and cons in that you gain the benefit of not performing work until it is actually needed, but on the flip side if you want the results now, there is overhead in the behind-the-scenes work that support deferred execution (it’s supported by the yield return / yield break keywords in C# which define iterators that maintain current state information). In general, the new LINQ syntax is preferred, but the older Array and List<T> ConvertAll() methods are still around, as is the Converter<TInput, TOutput> delegate. Sidebar: Variance support update in .NET 4.0 Just like our descriptions of Func and Action, these three early generic delegates also support more variance in assignment as of .NET 4.0.  Their new signatures are: 1: // comparison is contravariant on type being compared 2: public delegate int Comparison<in T>(T lhs, T rhs); 3:  4: // converter is contravariant on input and covariant on output 5: public delegate TOutput Contravariant<in TInput, out TOutput>(TInput input); 6:  7: // predicate is contravariant on input 8: public delegate bool Predicate<in T>(T obj); Thus these delegates can now be assigned to delegates allowing for contravariance (going to a more derived type) or covariance (going to a less derived type) based on whether the parameters are input or output, respectively. Summary Today, we wrapped up our generic delegates discussion by looking at three lesser-used delegates: Predicate<T>, Comparison<T>, and Converter<TInput, TOutput>.  All three of these tend to be replaced by their more generic Func equivalents in LINQ, but that doesn’t mean you shouldn’t understand what they do or can’t use them for your own code, as they do contain semantic meanings in their names that sometimes get lost in the more generic Func name.   Tweet Technorati Tags: C#,CSharp,.NET,Little Wonders,delegates,generics,Predicate,Converter,Comparison

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• C#/.NET &ndash; Finding an Item&rsquo;s Index in IEnumerable&lt;T&gt;

  - by James Michael Hare

  Sorry for the long blogging hiatus.  First it was, of course, the holidays hustle and bustle, then my brother and his wife gave birth to their son, so I’ve been away from my blogging for two weeks. Background: Finding an item’s index in List<T> is easy… Many times in our day to day programming activities, we want to find the index of an item in a collection.  Now, if we have a List<T> and we’re looking for the item itself this is trivial: 1: // assume have a list of ints: 2: var list = new List<int> { 1, 13, 42, 64, 121, 77, 5, 99, 132 }; 3:  4: // can find the exact item using IndexOf() 5: var pos = list.IndexOf(64); This will return the position of the item if it’s found, or –1 if not.  It’s easy to see how this works for primitive types where equality is well defined.  For complex types, however, it will attempt to compare them using EqualityComparer<T>.Default which, in a nutshell, relies on the object’s Equals() method. So what if we want to search for a condition instead of equality?  That’s also easy in a List<T> with the FindIndex() method: 1: // assume have a list of ints: 2: var list = new List<int> { 1, 13, 42, 64, 121, 77, 5, 99, 132 }; 3:  4: // finds index of first even number or -1 if not found. 5: var pos = list.FindIndex(i => i % 2 == 0);   Problem: Finding an item’s index in IEnumerable<T> is not so easy... This is all well and good for lists, but what if we want to do the same thing for IEnumerable<T>?  A collection of IEnumerable<T> has no indexing, so there’s no direct method to find an item’s index.  LINQ, as powerful as it is, gives us many tools to get us this information, but not in one step.  As with almost any problem involving collections, there are several ways to accomplish the same goal.  And once again as with almost any problem involving collections, the choice of the solution somewhat depends on the situation. So let’s look at a few possible alternatives.  I’m going to express each of these as extension methods for simplicity and consistency. Solution: The TakeWhile() and Count() combo One of the things you can do is to perform a TakeWhile() on the list as long as your find condition is not true, and then do a Count() of the items it took.  The only downside to this method is that if the item is not in the list, the index will be the full Count() of items, and not –1.  So if you don’t know the size of the list beforehand, this can be confusing. 1: // a collection of extra extension methods off IEnumerable<T> 2: public static class EnumerableExtensions 3: { 4: // Finds an item in the collection, similar to List<T>.FindIndex() 5: public static int FindIndex<T>(this IEnumerable<T> list, Predicate<T> finder) 6: { 7: // note if item not found, result is length and not -1! 8: return list.TakeWhile(i => !finder(i)).Count(); 9: } 10: } Personally, I don’t like switching the paradigm of not found away from –1, so this is one of my least favorites.  Solution: Select with index Many people don’t realize that there is an alternative form of the LINQ Select() method that will provide you an index of the item being selected: 1: list.Select( (item,index) => do something here with the item and/or index... ) This can come in handy, but must be treated with care.  This is because the index provided is only as pertains to the result of previous operations (if any).  For example: 1: // assume have a list of ints: 2: var list = new List<int> { 1, 13, 42, 64, 121, 77, 5, 99, 132 }; 3:  4: // you'd hope this would give you the indexes of the even numbers 5: // which would be 2, 3, 8, but in reality it gives you 0, 1, 2 6: list.Where(item => item % 2 == 0).Select((item,index) => index); The reason the example gives you the collection { 0, 1, 2 } is because the where clause passes over any items that are odd, and therefore only the even items are given to the select and only they are given indexes. Conversely, we can’t select the index and then test the item in a Where() clause, because then the Where() clause would be operating on the index and not the item! So, what we have to do is to select the item and index and put them together in an anonymous type.  It looks ugly, but it works: 1: // extensions defined on IEnumerable<T> 2: public static class EnumerableExtensions 3: { 4: // finds an item in a collection, similar to List<T>.FindIndex() 5: public static int FindIndex<T>(this IEnumerable<T> list, Predicate<T> finder) 6: { 7: // if you don't name the anonymous properties they are the variable names 8: return list.Select((item, index) => new { item, index }) 9: .Where(p => finder(p.item)) 10: .Select(p => p.index + 1) 11: .FirstOrDefault() - 1; 12: } 13: }     So let’s look at this, because i know it’s convoluted: First Select() joins the items and their indexes into an anonymous type. Where() filters that list to only the ones matching the predicate. Second Select() picks the index of the matches and adds 1 – this is to distinguish between not found and first item. FirstOrDefault() returns the first item found from the previous clauses or default (zero) if not found. Subtract one so that not found (zero) will be –1, and first item (one) will be zero. The bad thing is, this is ugly as hell and creates anonymous objects for each item tested until it finds the match.  This concerns me a bit but we’ll defer judgment until compare the relative performances below. Solution: Convert ToList() and use FindIndex() This solution is easy enough.  We know any IEnumerable<T> can be converted to List<T> using the LINQ extension method ToList(), so we can easily convert the collection to a list and then just use the FindIndex() method baked into List<T>. 1: // a collection of extension methods for IEnumerable<T> 2: public static class EnumerableExtensions 3: { 4: // find the index of an item in the collection similar to List<T>.FindIndex() 5: public static int FindIndex<T>(this IEnumerable<T> list, Predicate<T> finder) 6: { 7: return list.ToList().FindIndex(finder); 8: } 9: } This solution is simplicity itself!  It is very concise and elegant and you need not worry about anyone misinterpreting what it’s trying to do (as opposed to the more convoluted LINQ methods above). But the main thing I’m concerned about here is the performance hit to allocate the List<T> in the ToList() call, but once again we’ll explore that in a second. Solution: Roll your own FindIndex() for IEnumerable<T> Of course, you can always roll your own FindIndex() method for IEnumerable<T>.  It would be a very simple for loop which scans for the item and counts as it goes.  There’s many ways to do this, but one such way might look like: 1: // extension methods for IEnumerable<T> 2: public static class EnumerableExtensions 3: { 4: // Finds an item matching a predicate in the enumeration, much like List<T>.FindIndex() 5: public static int FindIndex<T>(this IEnumerable<T> list, Predicate<T> finder) 6: { 7: int index = 0; 8: foreach (var item in list) 9: { 10: if (finder(item)) 11: { 12: return index; 13: } 14:  15: index++; 16: } 17:  18: return -1; 19: } 20: } Well, it’s not quite simplicity, and those less familiar with LINQ may prefer it since it doesn’t include all of the lambdas and behind the scenes iterators that come with deferred execution.  But does having this long, blown out method really gain us much in performance? Comparison of Proposed Solutions So we’ve now seen four solutions, let’s analyze their collective performance.  I took each of the four methods described above and run them over 100,000 iterations of lists of size 10, 100, 1000, and 10000 and here’s the performance results.  Then I looked for targets at the begining of the list (best case), middle of the list (the average case) and not in the list (worst case as must scan all of the list). Each of the times below is the average time in milliseconds for one execution as computer over the 100,000 iterations: Searches Matching First Item (Best Case)   10 100 1000 10000 TakeWhile 0.0003 0.0003 0.0003 0.0003 Select 0.0005 0.0005 0.0005 0.0005 ToList 0.0002 0.0003 0.0013 0.0121 Manual 0.0001 0.0001 0.0001 0.0001   Searches Matching Middle Item (Average Case)   10 100 1000 10000 TakeWhile 0.0004 0.0020 0.0191 0.1889 Select 0.0008 0.0042 0.0387 0.3802 ToList 0.0002 0.0007 0.0057 0.0562 Manual 0.0002 0.0013 0.0129 0.1255   Searches Where Not Found (Worst Case)   10 100 1000 10000 TakeWhile 0.0006 0.0039 0.0381 0.3770 Select 0.0012 0.0081 0.0758 0.7583 ToList 0.0002 0.0012 0.0100 0.0996 Manual 0.0003 0.0026 0.0253 0.2514   Notice something interesting here, you’d think the “roll your own” loop would be the most efficient, but it only wins when the item is first (or very close to it) regardless of list size.  In almost all other cases though and in particular the average case and worst case, the ToList()/FindIndex() combo wins for performance, even though it is creating some temporary memory to hold the List<T>.  If you examine the algorithm, the reason why is most likely because once it’s in a ToList() form, internally FindIndex() scans the internal array which is much more efficient to iterate over.  Thus, it takes a one time performance hit (not including any GC impact) to create the List<T> but after that the performance is much better. Summary If you’re concerned about too many throw-away objects, you can always roll your own FindIndex() method, but for sheer simplicity and overall performance, using the ToList()/FindIndex() combo performs best on nearly all list sizes in the average and worst cases.    Technorati Tags: C#,.NET,Litte Wonders,BlackRabbitCoder,Software,LINQ,List

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• Set-Cookie Headers getting stripped in ASP.NET HttpHandlers

  - by Rick Strahl

  Yikes, I ran into a real bummer of an edge case yesterday in one of my older low level handler implementations (for West Wind Web Connection in this case). Basically this handler is a connector for a backend Web framework that creates self contained HTTP output. An ASP.NET Handler captures the full output, and then shoves the result down the ASP.NET Response object pipeline writing out the content into the Response.OutputStream and seperately sending the HttpHeaders in the Response.Headers collection. The headers turned out to be the problem and specifically Http Cookies, which for some reason ended up getting stripped out in some scenarios. My handler works like this: Basically the HTTP response from the backend app would return a full set of HTTP headers plus the content. The ASP.NET handler would read the headers one at a time and then dump them out via Response.AppendHeader(). But I found that in some situations Set-Cookie headers sent along were simply stripped inside of the Http Handler. After a bunch of back and forth with some folks from Microsoft (thanks Damien and Levi!) I managed to pin this down to a very narrow edge scenario. It's easiest to demonstrate the problem with a simple example HttpHandler implementation. The following simulates the very much simplified output generation process that fails in my handler. Specifically I have a couple of headers including a Set-Cookie header and some output that gets written into the Response object.using System.Web; namespace wwThreads { public class Handler : IHttpHandler { /* NOTE: * * Run as a web.config set handler (see entry below) * * Best way is to look at the HTTP Headers in Fiddler * or Chrome/FireBug/IE tools and look for the * WWHTREADSID cookie in the outgoing Response headers * ( If the cookie is not there you see the problem! ) */ public void ProcessRequest(HttpContext context) { HttpRequest request = context.Request; HttpResponse response = context.Response; // If ClearHeaders is used Set-Cookie header gets removed! // if commented header is sent... response.ClearHeaders(); response.ClearContent(); // Demonstrate that other headers make it response.AppendHeader("RequestId", "asdasdasd"); // This cookie gets removed when ClearHeaders above is called // When ClearHEaders is omitted above the cookie renders response.AppendHeader("Set-Cookie", "WWTHREADSID=ThisIsThEValue; path=/"); // *** This always works, even when explicit // Set-Cookie above fails and ClearHeaders is called //response.Cookies.Add(new HttpCookie("WWTHREADSID", "ThisIsTheValue")); response.Write(@"Output was created.<hr/> Check output with Fiddler or HTTP Proxy to see whether cookie was sent."); } public bool IsReusable { get { return false; } } } } In order to see the problem behavior this code has to be inside of an HttpHandler, and specifically in a handler defined in web.config with: <add name=".ck_handler" path="handler.ck" verb="*" type="wwThreads.Handler" preCondition="integratedMode" /> Note: Oddly enough this problem manifests only when configured through web.config, not in an ASHX handler, nor if you paste that same code into an ASPX page or MVC controller. What's the problem exactly? The code above simulates the more complex code in my live handler that picks up the HTTP response from the backend application and then peels out the headers and sends them one at a time via Response.AppendHeader. One of the headers in my app can be one or more Set-Cookie. I found that the Set-Cookie headers were not making it into the Response headers output. Here's the Chrome Http Inspector trace: Notice, no Set-Cookie header in the Response headers! Now, running the very same request after removing the call to Response.ClearHeaders() command, the cookie header shows up just fine: As you might expect it took a while to track this down. At first I thought my backend was not sending the headers but after closer checks I found that indeed the headers were set in the backend HTTP response, and they were indeed getting set via Response.AppendHeader() in the handler code. Yet, no cookie in the output. In the simulated example the problem is this line:response.AppendHeader("Set-Cookie", "WWTHREADSID=ThisIsThEValue; path=/"); which in my live code is more dynamic ( ie. AppendHeader(token[0],token[1[]) )as it parses through the headers. Bizzaro Land: Response.ClearHeaders() causes Cookie to get stripped Now, here is where it really gets bizarre: The problem occurs only if: Response.ClearHeaders() was called before headers are added It only occurs in Http Handlers declared in web.config Clearly this is an edge of an edge case but of course - knowing my relationship with Mr. Murphy - I ended up running smack into this problem. So in the code above if you remove the call to ClearHeaders(), the cookie gets set!  Add it back in and the cookie is not there. If I run the above code in an ASHX handler it works. If I paste the same code (with a Response.End()) into an ASPX page, or MVC controller it all works. Only in the HttpHandler configured through Web.config does it fail! Cue the Twilight Zone Music. Workarounds As is often the case the fix for this once you know the problem is not too difficult. The difficulty lies in tracking inconsistencies like this down. Luckily there are a few simple workarounds for the Cookie issue. Don't use AppendHeader for Cookies The easiest and obvious solution to this problem is simply not use Response.AppendHeader() to set Cookies. Duh! Under normal circumstances in application level code there's rarely a reason to write out a cookie like this:response.AppendHeader("Set-Cookie", "WWTHREADSID=ThisIsThEValue; path=/"); but rather create the cookie using the Response.Cookies collection:response.Cookies.Add(new HttpCookie("WWTHREADSID", "ThisIsTheValue")); Unfortunately, in my case where I dynamically read headers from the original output and then dynamically  write header key value pairs back  programmatically into the Response.Headers collection, I actually don't look at each header specifically so in my case the cookie is just another header. My first thought was to simply trap for the Set-Cookie header and then parse out the cookie and create a Cookie object instead. But given that cookies can have a lot of different options this is not exactly trivial, plus I don't really want to fuck around with cookie values which can be notoriously brittle. Don't use Response.ClearHeaders() The real mystery in all this is why calling Response.ClearHeaders() prevents a cookie value later written with Response.AppendHeader() to fail. I fired up Reflector and took a quick look at System.Web and HttpResponse.ClearHeaders. There's all sorts of resetting going on but nothing that seems to indicate that headers should be removed later on in the request. The code in ClearHeaders() does access the HttpWorkerRequest, which is the low level interface directly into IIS, and so I suspect it's actually IIS that's stripping the headers and not ASP.NET, but it's hard to know. Somebody from Microsoft and the IIS team would have to comment on that. In my application it's probably safe to simply skip ClearHeaders() in my handler. The ClearHeaders/ClearContent was mainly for safety but after reviewing my code there really should never be a reason that headers would be set prior to this method firing. However, if for whatever reason headers do need to be cleared, it's easy enough to manually clear the headers out:private void RemoveHeaders(HttpResponse response) { List<string> headers = new List<string>(); foreach (string header in response.Headers) { headers.Add(header); } foreach (string header in headers) { response.Headers.Remove(header); } response.Cookies.Clear(); } Now I can replace the call the Response.ClearHeaders() and I don't get the funky side-effects from Response.ClearHeaders(). Summary I realize this is a total edge case as this occurs only in HttpHandlers that are manually configured. It looks like you'll never run into this in any of the higher level ASP.NET frameworks or even in ASHX handlers - only web.config defined handlers - which is really, really odd. After all those frameworks use the same underlying ASP.NET architecture. Hopefully somebody from Microsoft has an idea what crazy dependency was triggered here to make this fail. IAC, there are workarounds to this should you run into it, although I bet when you do run into it, it'll likely take a bit of time to find the problem or even this post in a search because it's not easily to correlate the problem to the solution. It's quite possible that more than cookies are affected by this behavior. Searching for a solution I read a few other accounts where headers like Referer were mysteriously disappearing, and it's possible that something similar is happening in those cases. Again, extreme edge case, but I'm writing this up here as documentation for myself and possibly some others that might have run into this. © Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET   IIS7   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• CodePlex Daily Summary for Monday, November 12, 2012

  CodePlex Daily Summary for Monday, November 12, 2012Popular ReleasesAX 2012 Custom Operating Units: AXPOM (beta): This is beta version of the tool. There are some known issues that will be fixed in the next upcoming release.????: ???? 1.0: ????Unicode IVS Add-in for Microsoft Office: Unicode IVS Add-in for Microsoft Office: Unicode IVS Add-in for Microsoft Office ??? ?????、Unicode IVS?????????????????Unicode IVS???????????????。??、??????????????、?????????????????????????????。EXCEL??、??、????????：DataPie（??MSSQL 2008、ORACLE、ACCESS 2007）: DatePie3.4.2: DatePie3.4.2Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.74: fix for issue #18836 - sometimes throws null-reference errors in ActivationObject.AnalyzeScope method. add back the Context object's 8-parameter constructor, since someone has code that's using it. throw a low-pri warning if an expression statement is == or ===; warn that the developer may have meant an assignment (=). if window.XXXX or window"XXXX" is encountered, add XXXX (as long as it's a valid JavaScript identifier) to the known globals so subsequent references to XXXX won't throw ...Home Access Plus+: v8.3: Changes: Fixed: A odd scroll bar showing up for no reason Changed: Added some code to hopefully sort out the details view when there is a small number of files Fixed: Where the details toolbar shows in the wrong place until you scroll Fixed: Where the Help Desk live tile shows all open tiles, instead of user specific tiles (admins still see all) Added: Powerpoint Files Filter Added: Print style for Booking System Added: Silent check for the logon tracker Updated: Logon Tracker I...Silverlight 4 & 5 Persian DatePicker: Silverlight 4 and 5 Persian DatePicker 1.5: - Improved DateTime Parser.???????: Monitor 2012-11-11: This is the first releaseVidCoder: 1.4.5 Beta: Removed the old Advanced user interface and moved x264 preset/profile/tune there instead. The functionality is still available through editing the options string. Added ability to specify the H.264 level. Added ability to choose VidCoder's interface language. If you are interested in translating, we can get VidCoder in your language! Updated WPF text rendering to use the better Display mode. Updated HandBrake core to SVN 5045. Removed logic that forced the .m4v extension in certain ...ImageGlass: Version 1.5: http://i1214.photobucket.com/albums/cc483/phapsuxeko/ImageGlass/1.png v1.5.4401.3015 Thumbnail bar: Increase loading speed Thumbnail image with ratio Support personal customization: mouse up, mouse down, mouse hover, selected item... Scroll to show all items Image viewer Zoom by scroll, or selected rectangle Speed up loading Zoom to cursor point New background design and customization and others... v1.5.4430.483 Thumbnail bar: Auto move scroll bar to selected image Show / Hi...Building Windows 8 Apps with C# and XAML: Full Source Chapters 1 - 10 for Windows 8 Fix 002: This is the full source from all chapters of the book, compiled and tested on Windows 8 RTM. Includes: A fix for the Netflix example from Chapter 6 that was missing a service reference A fix for the ImageHelper issue (images were not being saved) - this was due to the buffer being inadequate and required streaming the writeable bitmap to a buffer first before encoding and savingmyCollections: Version 2.3.2.0: New in this version : Added TheGamesDB.net API for Games and NDS Added Support for Windows Media Center Added Support for myMovies Added Support for XBMC Added Support for Dune HD Added Support for Mede8er Added Support for WD HDTV Added Fast search options Added order by Artist/Album for music You can now create covers and background for games You can now update your ID3 tag with the info of myCollections Fixed several provider Performance improvement New Splash ...Draw: Draw 1.0: Drawing PadPlayer Framework by Microsoft: Player Framework for Windows 8 (v1.0): IMPORTANT: List of breaking changes from preview 7 Ability to move control panel or individual elements outside media player. more info... New Entertainment app theme for out of the box support for Windows 8 Entertainment app guidelines. more info... VSIX reference names shortened. Allows seeing plugin name from "Add Reference" dialog without resizing. FreeWheel SmartXML now supports new "Standard" event callback type. Other minor misc fixes and improvements ADDITIONAL DOWNLOADSSmo...WebSearch.Net: WebSearch.Net 3.1: WebSearch.Net is an open-source research platform that provides uniform data source access, data modeling, feature calculation, data mining, etc. It facilitates the experiments of web search researchers due to its high flexibility and extensibility. The platform can be used or extended by any language compatible for .Net 2 framework, from C# (recommended), VB.Net to C++ and Java. Thanks to the large coverage of knowledge in web search research, it is necessary to model the techniques and main...Umbraco CMS: Umbraco 4.10.0: NugetNuGet BlogRead the release blog post for 4.10.0. Whats newMVC support New request pipeline Many, many bugfixes (see the issue tracker for a complete list) Read the documentation for the MVC bits. Breaking changesWe have done all we can not to break backwards compatibility, but we had to do some minor breaking changes: Removed graphicHeadlineFormat config setting from umbracoSettings.config (an old relic from the 3.x days) U4-690 DynamicNode ChildrenAsList was fixed, altering it'...SQL Server Partitioned Table Framework: Partitioned Table Framework Release 1.0: SQL Server 2012 ReleaseSharePoint Manager 2013: SharePoint Manager 2013 Release ver 1.0.12.1106: SharePoint Manager 2013 Release (ver: 1.0.12.1106) is now ready for SharePoint 2013. The new version has an expanded view of the SharePoint object model and has been tested on SharePoint 2013 RTM. As a bonus, the new version is also available for SharePoint 2010 as a separate download.Fiskalizacija za developere: FiskalizacijaDev 1.2: Verzija 1.2. je, prije svega, odgovor na novu verziju Tehnicke specifikacije (v1.1.) koja je objavljena prije nekoliko dana. Pored novosti vezanih uz (sitne) izmjene u spomenutoj novoj verziji Tehnicke dokumentacije, projekt smo prošili sa nekim dodatnim feature-ima od kojih je vecina proizašla iz vaših prijedloga - hvala :) Novosti u v1.2. su: - Neusuglašenost zahtjeva (http://fiskalizacija.codeplex.com/workitem/645) - Sample projekt - iznosi se množe sa 100 (http://fiskalizacija.codeplex.c...MFCMAPI: October 2012 Release: Build: 15.0.0.1036 Full release notes at SGriffin's blog. If you just want to run the MFCMAPI or MrMAPI, get the executables. If you want to debug them, get the symbol files and the source. The 64 bit builds will only work on a machine with Outlook 2010 64 bit installed. All other machines should use the 32 bit builds, regardless of the operating system. Facebook BadgeNew Projects.NET C# Wrapper for IQFeed API by Sentinel: An API for DTN IQFeed writtein in C#. Supports: - Historical Data Requests, - Lookup Tables - Level 1 - Level 2 - NewsBaiduMap: ????????API?????Bananagrams: An experimental Java project to find the most efficient strategy of playing Bannagrams, the popular game that I take absolutely no credit for inventing.Cloud Wallet: Don't try to remember every credit card, email, forum and account password of yours. Store them with Cloud Wallet in the skydrive and get them needed.Customer Contact System: System for Local Authorities/Government Bodies to manage enquiries from members of the public in their administrative area.daniel's little electronical bear: Hey, this is Daniel's idea that write her girlfriend a vivid little e-pet. So Daniel is just about to carry on this plan and hopefully fulfill it sooner or later. If you wanna give any advice, please don't hesitate to call me at any time,even ideas is OK!danielzhang0212@gmail.comfacebook page vote and like sample: facebook page vote and like sampleFriendly URL: This application is designed to help large organizations assign simple and memorable URL's to otherwise complicated or non-memorable URL's. GameSDK - Simple Game SDK with events: This game SDK use events for letting know each player through a game board when an events occurs. This is a simple SDK, easily adaptable to your project.GIF o Magic Prototype: GIF o Magic PrototypeHFS+ Driver Installer for Windows: Simple utility to install Read-Only HFS+ Driver to read Mac partitions from Windows.invrt: Simplest-that-could-possibly work inversion of control framework. Written in C#Kwd.Summary: Orchard module to provide alternate summary text for content itemsLogJam: LogJam will provide a modern, efficient, and productive framework for trace logging and metrics logging for all projects. LogJam is currently pre-alpha.Mi-DevEnv: Mi-DevEnv is an integrated set of PowerShell scripts to create virtual machines and populate them with software & tools e.g.: SharePoint,CRM,SQL,Office,K2 & VS.Mltools: mini tools for browser game.More Space Invaders: more then another space invadersMP3 Art Embedder: Embed cover art into MP3 filesMultiple GeoCoder: Serverside geocoding wrapper for various geocoding services. Supports a failover in the event you get throttled.My list: mvc3 project to test some frameworksMyFinalProject_WeamBinjumah: It is a website based on web 2.0 which about sea cruises' experiences with people who love amazing sea cruises. The website will offer most of web 2.0 features.netcached - memcached client for .NET: netcached is a lightweight, high performance .NET client for memcached protocol.paipai: paipaiProjeto Zeus: PROJETO REALIZADO COMO TRABALHO ACADÊMICO.Roy's Tools: Roy's ToolsSuperCotka: SuperCotkaSzoftvertechnológia beadandó: Árva Balázs beadandójának projektvezeto oldalat az ELTE szoftvertechnológia tantárgyára.Twi.Fly: Twi.Fly is designed to change the way that you write most of your code.Coding likes flying, more than twice speed.Unicode IVS Add-in for Microsoft Office: "Unicode IVS Add-in for Microsoft Office" makes Microsoft Office 2007 and 2010 capable to load, save and edit documents contains Unicode IVS.Uyghur Named Date: Generate Uyghur named date string. ???????? ??? ?????? ????? ????? ?????Windows 8 Camp BH: Projeto contendo conteudo de ajuda para o Windows 8 Camp oferecido pelo Microsoft Inovation Center de Belo Horizonte.???????: ??wpf??????? ?? ??

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• Tools of the Trade

  - by Ajarn Mark Caldwell

  I got pretty excited a couple of days ago when my new laptop arrived. “The new phone books are here!  The new phone books are here!  I’m a somebody!” - Steve Martin in The Jerk It is a Dell Precision M4500 with an Intel i7 Core 2.8 GHZ running 64-bit Windows 7 with a 15.6” widescreen, 8 GB RAM, 256 GB SSD.  For some of you high fliers, this may be nothing to write home about, but compared to the 32–bit Windows XP laptop with 2 GB of RAM and a regular hard disk that I’m coming from, it’s a really nice step forward.  I won’t even bore you with the details of the desktop PC I was first given when I started here 5 1/2 years ago.  Let’s just say that things have improved.  One really nice thing is that while we are definitely running a lean and mean department in terms of staffing, my boss believes in supporting that lean staff with good tools in order to stay lean instead of having to spend even more money on additional employees.  Of course, that only goes so far, and at some point you have to add more people in order to get more work done, which is why we are bringing on-board a new employee and a new contract developer next week.  But that’s a different story for a different time. But the main topic for this post is to highlight the variety of tools that I use in my job and that you might find useful, too.  This is easy to do right now because the process of building up my new laptop from scratch has forced me to assemble a list of software that had to be installed and configured.  Keep in mind as you look through this list that I play many roles in our company.  My official title is Software Engineering Manager, but in addition to managing the team, I am also an active ASP.NET and SQL developer, the Database Administrator, and 50% of the SAN Administrator team.  So, without further ado, here are the tools and some comments about why I use them: Tool Purpose Virtual Clone Drive Easily mount an ISO image as a DVD Drive.  This is particularly handy when you are downloading disk images from Microsoft for your tools. SQL Server 2008 R2 Developer Edition We are migrating all of our active systems to SQL 2008 R2.  Developer Edition has all the features of Enterprise Edition, but intended for development use. SQL Server 2005 Developer Edition (BIDS ONLY) The migration to SSRS 2008 R2 is just getting started, and in the meantime, maintenance work still has to be done on the reports on our SQL 2005 server.  For some reason, you can’t use BIDS from 2008 to write reports for a 2005 server.  There is some different format and when you open 2005 reports in 2008 BIDS, it forces you to upgrade, and they can no longer be uploaded to a 2005 server.  Hopefully Microsoft will fix this soon in some manner similar to Visual Studio now allows you to pick which version of the .NET Framework you are coding against. Visual Studio 2010 Premium All of our application development is in ASP.NET, and we might as well use the tool designed for it. I’ve used a version of Visual Studio going all the way back to VB 6.0 and Visual Interdev. Vault Professional Client Several years ago we replaced Visual Source Safe with SourceGear Vault (then Fortress, and now Vault Pro), and I love it.  It is very reliable with low overhead - perfect for a small to medium size development team.  And being a small ISV, their support is exceptional. Red-Gate Developer Bundle with the SQL Source Control update for Vault I first used, and fell in love with, SQL Prompt shortly before Red-Gate bought it, and then Red-Gate’s first release made me love it even more.  SQL Refactor (which has since been rolled into the latest version of SQL Prompt) has saved me many hours and migraine’s trying to understand somebody else’s code when their indenting was nonexistant, or worse, irrational.  SQL Compare has been awesome for troubleshooting potential schema issues between different instances of system databases.  SQL Data Compare helped us identify the cause behind a bug which appeared in PROD but could not be reproduced in a nearly (but not quite exactly) identical copy in UAT.  And the newest tool we are embracing: SQL Source Control.  I blogged about it here (and here, and here) last December.  This is really going to help us keep each developer’s copy of the database in sync with one another. Fiddler Helps you watch the whole traffic stream on web visits.  Haven’t used it a lot, but it did help me track down some odd 404 errors we were finding in our own application logs.  Has some other JavaScript troubleshooting capabilities, but some of its usefulness has been supplanted by the Developer Tools option in IE8. Funduc Search & Replace Find any string anywhere in a mound of source code really, really fast.  Does RegEx searches, if you understand that foreign language.  Has really helped with some refactoring work to pinpoint, for example, everywhere a particular stored procedure is referenced, whether in .NET code or other SQL procedures (which we have in script files).  Provides in-context preview of the search results.  Fantastic tool, and a bargain price. SciTE SciTE is a Scintilla based Text Editor and it is a fantastic, light-weight tool for quickly reviewing (or writing) program code, SQL scripts, and extract files.  It has language-specific syntax highlighting.  I used it to write several batch and CMD programs a year ago, and to examine data extract files for exchanging information with other systems.  Extremely handy are the options to View End of Line and View Whitespace.  Ever receive a file that is supposed to use CRLF as an end-of-line marker, but really only has CRs?  SciTE will quickly make that visible. Infragistics Controls We do a lot of ASP.NET development, and frequently use the WebGrid, WebTab, and date picker controls.  We will likely be implementing the Hierarchical Data Grid soon.  Infragistics has control suites for WebForms, WinForms, Silverlight, and coming soon MVC/JQuery. WinZip - WITH Command-Line add-in The classic compression program with a great command-line interface that allows me to build those CMD (and soon PowerShell) programs for automated compression jobs.  Our versioned Build packages are zip files. XML Notepad Haven’t used this a lot myself, but one of my team really likes it for examining large XML files. LINQPad Again, haven’t used this one a lot, but it was recommended to me for learning and practicing my LINQ skills which will come in handy as we implement Entity Framework. SQL Sentry Plan Explorer SQL Server Show Plan on steroids.  Great for helping you focus on the parts of a large query that are of most importance.  Also great for just compressing the graphical plan into more readable layout. Araxis Merge A great DIFF and Merge tool.  SourceGear provides a great tool called DiffMerge that we use all the time, but occasionally, I like the cross-edit capabilities of Araxis Merge.  For a while, we also produced DIFF reports in HTML that showed all the changes that occurred between two releases.  This was most important when we were putting out very small, but very important hot fixes on a very politically hot system.  The reports produced by Araxis Merge gave the Director of IS assurance that we were not accidentally introducing ripples throughout the system with our releases. Idera SQL Admin Toolset A great collection of tools including a password checker to help analyze your SQL Server for weak user passwords, a Backup Status tool to quickly scan a large list of servers and databases to identify any that are overdue for backups.  Particularly helpful for highlighting new databases that have been deployed without getting included in your backup processing.  I also like Space Analyzer to keep an eye on disk space consumed by database files. Idera SQL Job Manager This free tool provides a nice calendar view of SQL Server Job Schedules, but to a degree, you also get what you pay for.  We will be purchasing SQL Sentry Event Manager later this year as an even better job schedule reviewer/manager.  But in the meantime, this at least gives me a good view on potential resource conflicts across multiple instances of SQL Server. DBFViewer 2000 I inherited a couple of FoxPro databases that I have to keep an eye on occasionally and have not yet been able to migrate them to SQL Server. Balsamiq Mockups We are still in evaluation-mode on this tool, but I really like it as a quick UI mockup tool that does not require Visual Studio, so someone other than a programmer can do UI design.  The interface looks hand-drawn which definitely has some psychological benefits when communicating to users, too. FeedDemon I have to stay on top of my WAY TOO MANY blog subscriptions somehow.  I may read blogs on a couple of different computers, and FeedDemon’s integration with Google Reader allows me to keep them all in sync.  I don’t particularly like the Google Reader interface, or the fact that it always wanted to mark articles as read just because I scrolled past them.  FeedDemon solves this problem for me, and provides a multi-tabbed interface which is good because fairly frequently one blog will link to something else I want to read, and I can end up with a half-dozen open tabs all from one article. Synergy+ In my office, I run four monitors across two computers all with one mouse and keyboard.  Synergy is the magic software that makes this work. TweetDeck I’m not the most active Tweeter in the world, but when I want to check-in with the Twitterverse, this really helps.  I have found the #sqlhelp and #PoshHelp hash tags particularly useful, and I also have columns setup to make it easy to monitor #sqlpass, #PASSProfDev, and short term events like #sqlsat68.   Whew!  That’s a lot.  No wonder it took me a couple of days to get everything setup the way I wanted it.  Oh, that and actually getting some work accomplished at the same time.  Anyway, I know that is a huge dump of info, and most people never make it here to the end, so for those who did, let me say, CONGRATULATIONS, you made it! I hope you’ll find a new tool or two to make your work life a little easier.

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• Web API, JavaScript, Chrome &amp; Cross-Origin Resource Sharing

  - by Brian Lanham

  The team spent much of the week working through this issues related to Chrome running on Windows 8 consuming cross-origin resources using Web API.  We thought it was resolved on day 2 but it resurfaced the next day.  We definitely resolved it today though.  I believe I do not fully understand the situation but I am going to explain what I know in an effort to help you avoid and/or resolve a similar issue. References We referenced many sources during our trial-and-error troubleshooting.  These are the links we reference in order of applicability to the solution: Zoiner Tejada JavaScript and other material from -> http://www.devproconnections.com/content1/topic/microsoft-azure-cors-141869/catpath/windows-azure-platform2/page/3 WebDAV Where I learned about “Accept” –>  http://www-jo.se/f.pfleger/cors-and-iis? IT Hit Tells about NOT using ‘*’ –> http://www.webdavsystem.com/ajax/programming/cross_origin_requests Carlos Figueira Sample back-end code (newer) –> http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d (older version) –> http://code.msdn.microsoft.com/CORS-support-in-ASPNET-Web-01e9980a   Background As a measure of protection, Web designers (W3C) and implementers (Google, Microsoft, Mozilla) made it so that a request, especially a JSON request (but really any URL), sent from one domain to another will only work if the requestee “knows” about the requester and allows requests from it. So, for example, if you write a ASP.NET MVC Web API service and try to consume it from multiple apps, the browsers used may (will?) indicate that you are not allowed by showing an “Access-Control-Allow-Origin” error indicating the requester is not allowed to make requests. Internet Explorer (big surprise) is the odd-hair-colored step-child in this mix. It seems that running locally at least IE allows this for development purposes.  Chrome and Firefox do not.  In fact, Chrome is quite restrictive.  Notice the images below. IE shows data (a tabular view with one row for each day of a week) while Chrome does not (trust me, neither does Firefox).  Further, the Chrome developer console shows an XmlHttpRequest (XHR) error. Screen captures from IE (left) and Chrome (right). Note that Chrome does not display data and the console shows an XHR error. Why does this happen? The Web browser submits these requests and processes the responses and each browser is different. Okay, so, IE is probably the only one that’s truly different.  However, Chrome has a specific process of performing a “pre-flight” check to make sure the service can respond to an “Access-Control-Allow-Origin” or Cross-Origin Resource Sharing (CORS) request.  So basically, the sequence is, if I understand correctly:  1)Page Loads –> 2)JavaScript Request Processed by Browser –> 3)Browsers Prepares to Submit Request –> 4)[Chrome] Browser Submits Pre-Flight Request –> 5)Server Responds with HTTP 200 –> 6)Browser Submits Request –> 7)Server Responds with Data –> 8)Page Shows Data This situation occurs for both GET and POST methods.  Typically, GET methods are called with query string parameters so there is no data posted.  Instead, the requesting domain needs to be permitted to request data but generally nothing more is required.  POSTs on the other hand send form data.  Therefore, more configuration is required (you’ll see the configuration below).  AJAX requests are not friendly with this (POSTs) either because they don’t post in a form. How to fix it. The team went through many iterations of self-hair removal and we think we finally have a working solution.  The trial-and-error approach eventually worked and we referenced many sources for the information.  I indicate those references above.  There are basically three (3) tasks needed to make this work. Assumptions: You are using Visual Studio, Web API, JavaScript, and have Cross-Origin Resource Sharing, and several browsers. 1. Configure the client Joel Cochran centralized our “cors-oriented” JavaScript (from here). There are two calls including one for GET and one for POST function(url, data, callback) {             console.log(data);             $.support.cors = true;             var jqxhr = $.post(url, data, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("post", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send(data);                     } else {                         console.log(">" + jqXhHR.status);                         alert("corsAjax.post error: " + status + ", " + errorThrown);                     }                 });         }; The GET CORS JavaScript function (credit to Zoiner Tejada) function(url, callback) {             $.support.cors = true;             var jqxhr = $.get(url, null, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("get", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send();                     } else {                         alert("CORS is not supported in this browser or from this origin.");                     }                 });         }; The POST CORS JavaScript function (credit to Zoiner Tejada) Now you need to call these functions to get and post your data (instead of, say, using $.Ajax). Here is a GET example: corsAjax.get(url, function(data) { if (data !== null && data.length !== undefined) { // do something with data } }); And here is a POST example: corsAjax.post(url, item); Simple…except…you’re not done yet. 2. Change Web API Controllers to Allow CORS There are actually two steps here.  Do you remember above when we mentioned the “pre-flight” check?  Chrome actually asks the server if it is allowed to ask it for cross-origin resource sharing access.  So you need to let the server know it’s okay.  This is a two-part activity.  a) Add the appropriate response header Access-Control-Allow-Origin, and b) permit the API functions to respond to various methods including GET, POST, and OPTIONS.  OPTIONS is the method that Chrome and other browsers use to ask the server if it can ask about permissions.  Here is an example of a Web API controller thus decorated: NOTE: You’ll see a lot of references to using “*” in the header value.  For security reasons, Chrome does NOT recognize this is valid. [HttpHeader("Access-Control-Allow-Origin", "http://localhost:51234")] [HttpHeader("Access-Control-Allow-Credentials", "true")] [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPATCH, COPY, MOVE, DELETE, MKCOL, LOCK, UNLOCK, PUT, GETLIB, VERSION-CONTROL, CHECKIN, CHECKOUT, UNCHECKOUT, REPORT, UPDATE, CANCELUPLOAD, HEAD, OPTIONS, GET, POST")] [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destination, Content-Type, Depth, User-Agent, X-File-Size, X-Requested-With, If-Modified-Since, X-File-Name, Cache-Control")] [HttpHeader("Access-Control-Max-Age", "3600")] public abstract class BaseApiController : ApiController {     [HttpGet]     [HttpOptions]     public IEnumerable<foo> GetFooItems(int id)     {         return foo.AsEnumerable();     }     [HttpPost]     [HttpOptions]     public void UpdateFooItem(FooItem fooItem)     {         // NOTE: The fooItem object may or may not         // (probably NOT) be set with actual data.         // If not, you need to extract the data from         // the posted form manually.         if (fooItem.Id == 0) // However you check for default...         {             // We use NewtonSoft.Json.             string jsonString = context.Request.Form.GetValues(0)[0].ToString();             Newtonsoft.Json.JsonSerializer js = new Newtonsoft.Json.JsonSerializer();             fooItem = js.Deserialize<FooItem>(new Newtonsoft.Json.JsonTextReader(new System.IO.StringReader(jsonString)));         }         // Update the set fooItem object.     } } Please note a few specific additions here: * The header attributes at the class level are required.  Note all of those methods and headers need to be specified but we find it works this way so we aren’t touching it. * Web API will actually deserialize the posted data into the object parameter of the called method on occasion but so far we don’t know why it does and doesn’t. * [HttpOptions] is, again, required for the pre-flight check. * The “Access-Control-Allow-Origin” response header should NOT NOT NOT contain an ‘*’. 3. Headers and Methods and Such We had most of this code in place but found that Chrome and Firefox still did not render the data.  Interestingly enough, Fiddler showed that the GET calls succeeded and the JSON data is returned properly.  We learned that among the headers set at the class level, we needed to add “ACCEPT”.  Note that I accidentally added it to methods and to headers.  Adding it to methods worked but I don’t know why.  We added it to headers also for good measure. [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPA... [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destin... Next Steps That should do it.  If it doesn’t let us know.  What to do next?  * Don’t hardcode the allowed domains.  Note that port numbers and other domain name specifics will cause problems and must be specified.  If this changes do you really want to deploy updated software?  Consider Miguel Figueira’s approach in the following link to writing a custom HttpHeaderAttribute class that allows you to specify the domain names and then you can do it dynamically.  There are, of course, other ways to do it dynamically but this is a clean approach. http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d

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• Timeout Considerations for Solicit Response

  - by Michael Stephenson

  Background One of the clients I work with had been experiencing some issues for a while surrounding web service timeouts.  It's been a little challenging to work through the problems due to limitations in the diagnostic information available from one of the applications, but I learned some interesting things while troubleshooting the problem which don't seem to have been discussed much in the community so I thought I'd share my findings. In the scenario we have BizTalk trying to make calls to a .net web service which was exposed as a WSE 2 endpoint.  In the process BizTalk will try to make a large number of concurrent web service calls to the application, and the backend application has more than enough infrastructure and capability to handle the load. We have configured the <ConnectionManagement> section of the BizTalk configuration file to support up to 100 concurrent connections from each of our 2 BizTalk send servers to the web servers of the application. The problem we were facing was that the BizTalk side was reporting a significant number of timeouts when calling the web service.   One of the biggest issues was the challenge of being able to correlate a message from BizTalk to the IIS log in the .net application and the custom logs in the application especially when there was a fairly large number of servers hosting the web services.  However the key moment came when we were able to identify a specific call which had taken 40 seconds to execute on the server (yes a long time I know but that's a different story!).  Anyway we were able to identify that this had timed out on the BizTalk side.  Based on the normal 2 minute timeout we knew something unexpected was going on. From here I decided to do some experimentation and I wanted to start outside of BizTalk because my hunch was this was not a BizTalk behaviour but something which was being highlighted by BizTalk because of our large load.     Server-side - Sample Web Service To begin with I created a sample web service.  Nothing special just a vanilla asmx web service hosted in IIS6 on Windows 2003 Standard Edition.  The web service is just a hello world style web service as shown in the below picture.  The only key feature is that the server side web method has a 30 second sleep in it and will trace out some information before and after the thread is set to sleep.      In the configuration for this web service there again is nothing special it's pretty much the most plain simple web service you could build. Client-Side To begin looking at what was happening with our example I created a number of different ways to consume the web service. SoapHttpClientProtocol Example I created a small application which would use a normal proxy generated to call the web service.  It would iterate around a loop and make calls using the begin/end methods so I can do this asynchronously.  I would do a loop of 20 calls with the ConnectionManager configuration section supporting only 5 concurrent connections to the server.     <connectionManagement> <remove address="*"/> <add address = "*" maxconnection = "12" /> <add address = "http://<ServerName>" maxconnection = "5" />                         </connectionManagement> </system.net>     The below picture shows an example of the service calling code, key points are: I have configured the timeout of 40 seconds for the proxy I am using the asynchronous methods on the proxy to call the web service         The Test I would run the client and execute 21 calls to the web service.   The Results  Below is the client side trace showing what's happening on the client. In the below diagram is the web service side trace showing what's happening on the server Some observations on the results are: All of the calls were successful from the clients perspective You could see the next call starting on the server as soon as the previous one had completed Calls took significantly longer than 40 seconds from the start of our call to the return. In fact call 20 took 2 minutes and 30 seconds from the perspective of my code to execute even though I had set the timeout to 40 seconds     WSE 2 Sample In the second example I used the exact same code to call the web service again with a single exception that I modified the web service proxy to derive from WebServiceClient protocol which is part of WSE 2 (using SP3).  The below picture shows the basic code and the key points are: I have configured the timeout of 40 seconds for the proxy I am using the asynchronous methods on the proxy to call the web service        The Test This test would execute 21 calls from the client to the web service.   The Results  The below trace is from the client side: The below trace is from the server side:   Some observations on the trace results for this scenario are: With call 4 if you look at the server side trace it did not start executing on the server for a number of seconds after the other 4 initial calls which were accepted by the server. I re-ran the test and this happened a couple of times and not on most others so at this point I'm just putting this down to something unexpected happening on the development machine and we will leave this observation out of scope of this article. You can see that the client side trace statement executed almost immediately in all cases All calls after the initial few calls would timeout On the client side the calls that did timeout; timed out in a longer duration than the 40 seconds we set as the timeout You can see that as calls were completing on the server the next calls were starting to come through The calls that timed out on the client did actually connect to the server and their server side execution completed successfully     Elaboration on the findings Based on the above observations I have drawn the below sequence diagram to illustrate conceptually what is happening.  Everything except the final web service object is on the client side of the call. In the diagram below I've put two notes on the Web Service Proxy to show the two different places where the different base classes seem to start their timeout counters. From the earlier samples we can work out that the timeout counter for the WSE web service proxy starts before the one for the SoapHttpClientProtocol proxy and the WSE one includes the time to get a connection from the pool; whereas the Soap proxy timeout just covers the method execution. One interesting observation is if we rerun the above sample and increase the number of calls from 21 to 100,000 then for the WSE sample we will see a similar pattern where everything after the first few calls will timeout on the client as soon as it makes a connection to the server whereas the soap proxy will happily plug away and process all of the calls without a single timeout. I have actually set the sample running overnight and this did happen. At this point you are probably thinking the same thoughts I was at the time about the differences in behaviour and which is right and why are they different? I'm not sure there is a definitive answer to this in the documentation, or at least not that I could find! I think you just have to consider that they are different and they could have different effects depending on your messaging solution. In lots of situations this is just not an issue as your concurrent requests doesn't get to the situation where you end up throttling the web service calls on the client side, however this is definitely more common with an integration broker such as BizTalk where you often have high throughput requirements.  Some of the considerations you should make Based on this behaviour you should be aware of the following: In a .net application if you are making lots of concurrent web service calls from an application in an asynchronous manner your user may thing they are experiencing poor performance but you think your web service is working well. The problem could be that the client will have a default of 2 connections to remote servers so you should bear this in mind When you are developing a BizTalk solution or a .net solution with the WSE 2 stack you may experience timeouts under load and throttling the number of connections using the max connections element in the configuration file will not help you For an application using WSE2 or SoapHttpClientProtocol an expired timeout will not throw an error until after a connection to the server has been made so you should consider this in your transaction and durability patterns     Our Work Around In the short term for our specific scenario we know that we can handle this by just increasing our timeout value.  There is only a specific small window when we get lots of concurrent traffic that causes this scenario so we should be able to increase the timeout to take into consideration the additional client side wait, and on the odd occasion where we do get a timeout the BizTalk send port retry will handle this. What was causing our original problem was that for that short window we were getting a lot of retries which significantly increased the load on our send servers and highlighted the issue.  Longer Term Solution As a longer term solution this really gives us more ammunition to argue a migration to WCF. The application we are calling has some factors which limit the protocols we can use but with WCF we would have more control on the various timeout options because in WCF you can configure specific parts of the timeout. Summary I've had this blog post on my to do list for ages but hopefully it will be useful to some people to just understand this behaviour and to possibly help you with some performance issues you may have. I do not believe there is too much in the way of documentation particularly around WSE2 and ASMX in this area so again another bit of ammunition for migrating to WCF. I'll try to do a follow up post with the sample for WCF to show how this changes things.

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• Oracle Linux Tips and Tricks: Using SSH

  - by Robert Chase

  Out of all of the utilities available to systems administrators ssh is probably the most useful of them all. Not only does it allow you to log into systems securely, but it can also be used to copy files, tunnel IP traffic and run remote commands on distant servers. It’s truly the Swiss army knife of systems administration. Secure Shell, also known as ssh, was developed in 1995 by Tau Ylonen after the University of Technology in Finland suffered a password sniffing attack. Back then it was common to use tools like rcp, rsh, ftp and telnet to connect to systems and move files across the network. The main problem with these tools is they provide no security and transmitted data in plain text including sensitive login credentials. SSH provides this security by encrypting all traffic transmitted over the wire to protect from password sniffing attacks. One of the more common use cases involving SSH is found when using scp. Secure Copy (scp) transmits data between hosts using SSH and allows you to easily copy all types of files. The syntax for the scp command is: scp /pathlocal/filenamelocal remoteuser@remotehost:/pathremote/filenameremote In the following simple example, I move a file named myfile from the system test1 to the system test2. I am prompted to provide valid user credentials for the remote host before the transfer will proceed.  If I were only using ftp, this information would be unencrypted as it went across the wire.  However, because scp uses SSH, my user credentials and the file and its contents are confidential and remain secure throughout the transfer.  [user1@test1 ~]# scp /home/user1/myfile user1@test2:/home/user1user1@test2's password: myfile                                    100%    0     0.0KB/s   00:00 You can also use ssh to send network traffic and utilize the encryption built into ssh to protect traffic over the wire. This is known as an ssh tunnel. In order to utilize this feature, the server that you intend to connect to (the remote system) must have TCP forwarding enabled within the sshd configuraton. To enable TCP forwarding on the remote system, make sure AllowTCPForwarding is set to yes and enabled in the /etc/ssh/sshd_conf file: AllowTcpForwarding yes Once you have this configured, you can connect to the server and setup a local port which you can direct traffic to that will go over the secure tunnel. The following command will setup a tunnel on port 8989 on your local system. You can then redirect a web browser to use this local port, allowing the traffic to go through the encrypted tunnel to the remote system. It is important to select a local port that is not being used by a service and is not restricted by firewall rules.  In the following example the -D specifies a local dynamic application level port forwarding and the -N specifies not to execute a remote command.   ssh –D 8989 [email protected] -N You can also forward specific ports on both the local and remote host. The following example will setup a port forward on port 8080 and forward it to port 80 on the remote machine. ssh -L 8080:farwebserver.com:80 [email protected] You can even run remote commands via ssh which is quite useful for scripting or remote system administration tasks. The following example shows how to  log in remotely and execute the command ls –la in the home directory of the machine. Because ssh encrypts the traffic, the login credentials and output of the command are completely protected while they travel over the wire. [rchase@test1 ~]$ ssh rchase@test2 'ls -la'rchase@test2's password: total 24drwx------  2 rchase rchase 4096 Sep  6 15:17 .drwxr-xr-x. 3 root   root   4096 Sep  6 15:16 ..-rw-------  1 rchase rchase   12 Sep  6 15:17 .bash_history-rw-r--r--  1 rchase rchase   18 Dec 20  2012 .bash_logout-rw-r--r--  1 rchase rchase  176 Dec 20  2012 .bash_profile-rw-r--r--  1 rchase rchase  124 Dec 20  2012 .bashrc You can execute any command contained in the quotations marks as long as you have permission with the user account that you are using to log in. This can be very powerful and useful for collecting information for reports, remote controlling systems and performing systems administration tasks using shell scripts. To make your shell scripts even more useful and to automate logins you can use ssh keys for running commands remotely and securely without the need to enter a password. You can accomplish this with key based authentication. The first step in setting up key based authentication is to generate a public key for the system that you wish to log in from. In the following example you are generating a ssh key on a test system. In case you are wondering, this key was generated on a test VM that was destroyed after this article. [rchase@test1 .ssh]$ ssh-keygen -t rsaGenerating public/private rsa key pair.Enter file in which to save the key (/home/rchase/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/rchase/.ssh/id_rsa.Your public key has been saved in /home/rchase/.ssh/id_rsa.pub.The key fingerprint is:7a:8e:86:ef:59:70:ef:43:b7:ee:33:03:6e:6f:69:e8 rchase@test1The key's randomart image is:+--[ RSA 2048]----+|                 ||  . .            ||   o .           ||    . o o        ||   o o oS+       ||  +   o.= =      ||   o ..o.+ =     ||    . .+. =      ||     ...Eo       |+-----------------+ Now that you have the key generated on the local system you should to copy it to the target server into a temporary location. The user’s home directory is fine for this. [rchase@test1 .ssh]$ scp id_rsa.pub rchase@test2:/home/rchaserchase@test2's password: id_rsa.pub                  Now that the file has been copied to the server, you need to append it to the authorized_keys file. This should be appended to the end of the file in the event that there are other authorized keys on the system. [rchase@test2 ~]$ cat id_rsa.pub >> .ssh/authorized_keys Once the process is complete you are ready to login. Since you are using key based authentication you are not prompted for a password when logging into the system.   [rchase@test1 ~]$ ssh test2Last login: Fri Sep  6 17:42:02 2013 from test1 This makes it much easier to run remote commands. Here’s an example of the remote command from earlier. With no password it’s almost as if the command ran locally. [rchase@test1 ~]$ ssh test2 'ls -la'total 32drwx------  3 rchase rchase 4096 Sep  6 17:40 .drwxr-xr-x. 3 root   root   4096 Sep  6 15:16 ..-rw-------  1 rchase rchase   12 Sep  6 15:17 .bash_history-rw-r--r--  1 rchase rchase   18 Dec 20  2012 .bash_logout-rw-r--r--  1 rchase rchase  176 Dec 20  2012 .bash_profile-rw-r--r--  1 rchase rchase  124 Dec 20  2012 .bashrc As a security consideration it's important to note the permissions of .ssh and the authorized_keys file.  .ssh should be 700 and authorized_keys should be set to 600.  This prevents unauthorized access to ssh keys from other users on the system.   An even easier way to move keys back and forth is to use ssh-copy-id. Instead of copying the file and appending it manually to the authorized_keys file, ssh-copy-id does both steps at once for you.  Here’s an example of moving the same key using ssh-copy-id.The –i in the example is so that we can specify the path to the id file, which in this case is /home/rchase/.ssh/id_rsa.pub [rchase@test1]$ ssh-copy-id -i /home/rchase/.ssh/id_rsa.pub rchase@test2 One of the last tips that I will cover is the ssh config file. By using the ssh config file you can setup host aliases to make logins to hosts with odd ports or long hostnames much easier and simpler to remember. Here’s an example entry in our .ssh/config file. Host dev1 Hostname somereallylonghostname.somereallylongdomain.com Port 28372 User somereallylongusername12345678 Let’s compare the login process between the two. Which would you want to type and remember? ssh somereallylongusername12345678@ somereallylonghostname.somereallylongdomain.com –p 28372 ssh dev1 I hope you find these tips useful.  There are a number of tools used by system administrators to streamline processes and simplify workflows and whether you are new to Linux or a longtime user, I'm sure you will agree that SSH offers useful features that can be used every day.  Send me your comments and let us know the ways you  use SSH with Linux.  If you have other tools you would like to see covered in a similar post, send in your suggestions.

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• When someone deletes a shared data source in SSRS

  - by Rob Farley

  SQL Server Reporting Services plays nicely. You can have things in the catalogue that get shared. You can have Reports that have Links, Datasets that can be used across different reports, and Data Sources that can be used in a variety of ways too. So if you find that someone has deleted a shared data source, you potentially have a bit of a horror story going on. And this works for this month’s T-SQL Tuesday theme, hosted by Nick Haslam, who wants to hear about horror stories. I don’t write about LobsterPot client horror stories, so I’m writing about a situation that a fellow MVP friend asked me about recently instead. The best thing to do is to grab a recent backup of the ReportServer database, restore it somewhere, and figure out what’s changed. But of course, this isn’t always possible. And it’s much nicer to help someone with this kind of thing, rather than to be trying to fix it yourself when you’ve just deleted the wrong data source. Unfortunately, it lets you delete data sources, without trying to scream that the data source is shared across over 400 reports in over 100 folders, as was the case for my friend’s colleague. So, suddenly there’s a big problem – lots of reports are failing, and the time to turn it around is small. You probably know which data source has been deleted, but getting the shared data source back isn’t the hard part (that’s just a connection string really). The nasty bit is all the re-mapping, to get those 400 reports working again. I know from exploring this kind of stuff in the past that the ReportServer database (using its default name) has a table called dbo.Catalog to represent the catalogue, and that Reports are stored here. However, the information about what data sources these deployed reports are configured to use is stored in a different table, dbo.DataSource. You could be forgiven for thinking that shared data sources would live in this table, but they don’t – they’re catalogue items just like the reports. Let’s have a look at the structure of these two tables (although if you’re reading this because you have a disaster, feel free to skim past). Frustratingly, there doesn’t seem to be a Books Online page for this information, sorry about that. I’m also not going to look at all the columns, just ones that I find interesting enough to mention, and that are related to the problem at hand. These fields are consistent all the way through to SQL Server 2012 – there doesn’t seem to have been any changes here for quite a while. dbo.Catalog The Primary Key is ItemID. It’s a uniqueidentifier. I’m not going to comment any more on that. A minor nice point about using GUIDs in unfamiliar databases is that you can more easily figure out what’s what. But foreign keys are for that too… Path, Name and ParentID tell you where in the folder structure the item lives. Path isn’t actually required – you could’ve done recursive queries to get there. But as that would be quite painful, I’m more than happy for the Path column to be there. Path contains the Name as well, incidentally. Type tells you what kind of item it is. Some examples are 1 for a folder and 2 a report. 4 is linked reports, 5 is a data source, 6 is a report model. I forget the others for now (but feel free to put a comment giving the full list if you know it). Content is an image field, remembering that image doesn’t necessarily store images – these days we’d rather use varbinary(max), but even in SQL Server 2012, this field is still image. It stores the actual item definition in binary form, whether it’s actually an image, a report, whatever. LinkSourceID is used for Linked Reports, and has a self-referencing foreign key (allowing NULL, of course) back to ItemID. Parameter is an ntext field containing XML for the parameters of the report. Not sure why this couldn’t be a separate table, but I guess that’s just the way it goes. This field gets changed when the default parameters get changed in Report Manager. There is nothing in dbo.Catalog that describes the actual data sources that the report uses. The default data sources would be part of the Content field, as they are defined in the RDL, but when you deploy reports, you typically choose to NOT replace the data sources. Anyway, they’re not in this table. Maybe it was already considered a bit wide to throw in another ntext field, I’m not sure. They’re in dbo.DataSource instead. dbo.DataSource The Primary key is DSID. Yes it’s a uniqueidentifier... ItemID is a foreign key reference back to dbo.Catalog Fields such as ConnectionString, Prompt, UserName and Password do what they say on the tin, storing information about how to connect to the particular source in question. Link is a uniqueidentifier, which refers back to dbo.Catalog. This is used when a data source within a report refers back to a shared data source, rather than embedding the connection information itself. You’d think this should be enforced by foreign key, but it’s not. It does allow NULLs though. Flags this is an int, and I’ll come back to this. When a Data Source gets deleted out of dbo.Catalog, you might assume that it would be disallowed if there are references to it from dbo.DataSource. Well, you’d be wrong. And not because of the lack of a foreign key either. Deleting anything from the catalogue is done by calling a stored procedure called dbo.DeleteObject. You can look at the definition in there – it feels very much like the kind of Delete stored procedures that many people write, the kind of thing that means they don’t need to worry about allowing cascading deletes with foreign keys – because the stored procedure does the lot. Except that it doesn’t quite do that. If it deleted everything on a cascading delete, we’d’ve lost all the data sources as configured in dbo.DataSource, and that would be bad. This is fine if the ItemID from dbo.DataSource hooks in – if the report is being deleted. But if a shared data source is being deleted, you don’t want to lose the existence of the data source from the report. So it sets it to NULL, and it marks it as invalid. We see this code in that stored procedure. UPDATE [DataSource]    SET       [Flags] = [Flags] & 0x7FFFFFFD, -- broken link       [Link] = NULL FROM    [Catalog] AS C    INNER JOIN [DataSource] AS DS ON C.[ItemID] = DS.[Link] WHERE    (C.Path = @Path OR C.Path LIKE @Prefix ESCAPE '*') Unfortunately there’s no semi-colon on the end (but I’d rather they fix the ntext and image types first), and don’t get me started about using the table name in the UPDATE clause (it should use the alias DS). But there is a nice comment about what’s going on with the Flags field. What I’d LIKE it to do would be to set the connection information to a report-embedded copy of the connection information that’s in the shared data source, the one that’s about to be deleted. I understand that this would cause someone to lose the benefit of having the data sources configured in a central point, but I’d say that’s probably still slightly better than LOSING THE INFORMATION COMPLETELY. Sorry, rant over. I should log a Connect item – I’ll put that on my todo list. So it sets the Link field to NULL, and marks the Flags to tell you they’re broken. So this is your clue to fixing it. A bitwise AND with 0x7FFFFFFD is basically stripping out the ‘2’ bit from a number. So numbers like 2, 3, 6, 7, 10, 11, etc, whose binary representation ends in either 11 or 10 get turned into 0, 1, 4, 5, 8, 9, etc. We can test for it using a WHERE clause that matches the SET clause we’ve just used. I’d also recommend checking for Link being NULL and also having no ConnectionString. And join back to dbo.Catalog to get the path (including the name) of broken reports are – in case you get a surprise from a different data source being broken in the past. SELECT c.Path, ds.Name FROM dbo.[DataSource] AS ds JOIN dbo.[Catalog] AS c ON c.ItemID = ds.ItemID WHERE ds.[Flags] = ds.[Flags] & 0x7FFFFFFD AND ds.[Link] IS NULL AND ds.[ConnectionString] IS NULL; When I just ran this on my own machine, having deleted a data source to check my code, I noticed a Report Model in the list as well – so if you had thought it was just going to be reports that were broken, you’d be forgetting something. So to fix those reports, get your new data source created in the catalogue, and then find its ItemID by querying Catalog, using Path and Name to find it. And then use this value to fix them up. To fix the Flags field, just add 2. I prefer to use bitwise OR which should do the same. Use the OUTPUT clause to get a copy of the DSIDs of the ones you’re changing, just in case you need to revert something later after testing (doing it all in a transaction won’t help, because you’ll just lock out the table, stopping you from testing anything). UPDATE ds SET [Flags] = [Flags] | 2, [Link] = '3AE31CBA-BDB4-4FD1-94F4-580B7FAB939D' /*Insert your own GUID*/ OUTPUT deleted.Name, deleted.DSID, deleted.ItemID, deleted.Flags FROM dbo.[DataSource] AS ds JOIN dbo.[Catalog] AS c ON c.ItemID = ds.ItemID WHERE ds.[Flags] = ds.[Flags] & 0x7FFFFFFD AND ds.[Link] IS NULL AND ds.[ConnectionString] IS NULL; But please be careful. Your mileage may vary. And there’s no reason why 400-odd broken reports needs to be quite the nightmare that it could be. Really, it should be less than five minutes. @rob_farley

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• How to Implement Project Type "Copy", "Move", "Rename", and "Delete"

  - by Geertjan

  You've followed the NetBeans Project Type Tutorial and now you'd like to let the user copy, move, rename, and delete the projects conforming to your project type. When they right-click a project, they should see the relevant menu items and those menu items should provide dialogs for user interaction, followed by event handling code to deal with the current operation. Right now, at the end of the tutorial, the "Copy" and "Delete" menu items are present but disabled, while the "Move" and "Rename" menu items are absent: The NetBeans Project API provides a built-in mechanism out of the box that you can leverage for project-level "Copy", "Move", "Rename", and "Delete" actions. All the functionality is there for you to use, while all that you need to do is a bit of enablement and configuration, which is described below. To get started, read the following from the NetBeans Project API: http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/ActionProvider.html http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/CopyOperationImplementation.html http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/MoveOrRenameOperationImplementation.html http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/DeleteOperationImplementation.html Now, let's do some work. For each of the menu items we're interested in, we need to do the following: Provide enablement and invocation handling in an ActionProvider implementation. Provide appropriate OperationImplementation classes. Add the new classes to the Project Lookup. Make the Actions visible on the Project Node. Run the application and verify the Actions work as you'd like. Here we go: Create an ActionProvider. Here you specify the Actions that should be supported, the conditions under which they should be enabled, and what should happen when they're invoked, using lots of default code that lets you reuse the functionality provided by the NetBeans Project API: class CustomerActionProvider implements ActionProvider { @Override public String[] getSupportedActions() { return new String[]{ ActionProvider.COMMAND_RENAME, ActionProvider.COMMAND_MOVE, ActionProvider.COMMAND_COPY, ActionProvider.COMMAND_DELETE }; } @Override public void invokeAction(String string, Lookup lkp) throws IllegalArgumentException { if (string.equalsIgnoreCase(ActionProvider.COMMAND_RENAME)) { DefaultProjectOperations.performDefaultRenameOperation( CustomerProject.this, ""); } if (string.equalsIgnoreCase(ActionProvider.COMMAND_MOVE)) { DefaultProjectOperations.performDefaultMoveOperation( CustomerProject.this); } if (string.equalsIgnoreCase(ActionProvider.COMMAND_COPY)) { DefaultProjectOperations.performDefaultCopyOperation( CustomerProject.this); } if (string.equalsIgnoreCase(ActionProvider.COMMAND_DELETE)) { DefaultProjectOperations.performDefaultDeleteOperation( CustomerProject.this); } } @Override public boolean isActionEnabled(String command, Lookup lookup) throws IllegalArgumentException { if ((command.equals(ActionProvider.COMMAND_RENAME))) { return true; } else if ((command.equals(ActionProvider.COMMAND_MOVE))) { return true; } else if ((command.equals(ActionProvider.COMMAND_COPY))) { return true; } else if ((command.equals(ActionProvider.COMMAND_DELETE))) { return true; } return false; } } Importantly, to round off this step, add "new CustomerActionProvider()" to the "getLookup" method of the project. If you were to run the application right now, all the Actions we're interested in would be enabled (if they are visible, as described in step 4 below) but when you invoke any of them you'd get an error message because each of the DefaultProjectOperations above looks in the Lookup of the Project for the presence of an implementation of a class for handling the operation. That's what we're going to do in the next step. Provide Implementations of Project Operations. For each of our operations, the NetBeans Project API lets you implement classes to handle the operation. The dialogs for interacting with the project are provided by the NetBeans project system, but what happens with the folders and files during the operation can be influenced via the operations. Below are the simplest possible implementations, i.e., here we assume we want nothing special to happen. Each of the below needs to be in the Lookup of the Project in order for the operation invocation to succeed. private final class CustomerProjectMoveOrRenameOperation implements MoveOrRenameOperationImplementation { @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public List<FileObject> getDataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyRenaming() throws IOException { } @Override public void notifyRenamed(String nueName) throws IOException { } @Override public void notifyMoving() throws IOException { } @Override public void notifyMoved(Project original, File originalPath, String nueName) throws IOException { } } private final class CustomerProjectCopyOperation implements CopyOperationImplementation { @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public List<FileObject> getDataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyCopying() throws IOException { } @Override public void notifyCopied(Project prjct, File file, String string) throws IOException { } } private final class CustomerProjectDeleteOperation implements DeleteOperationImplementation { @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public List<FileObject> getDataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyDeleting() throws IOException { } @Override public void notifyDeleted() throws IOException { } } Also make sure to put the above methods into the Project Lookup. Check the Lookup of the Project. The "getLookup()" method of the project should now include the classes you created above, as shown in bold below: @Override public Lookup getLookup() { if (lkp == null) { lkp = Lookups.fixed(new Object[]{ this, new Info(), new CustomerProjectLogicalView(this), new CustomerCustomizerProvider(this), new CustomerActionProvider(), new CustomerProjectMoveOrRenameOperation(), new CustomerProjectCopyOperation(), new CustomerProjectDeleteOperation(), new ReportsSubprojectProvider(this), }); } return lkp; } Make Actions Visible on the Project Node. The NetBeans Project API gives you a number of CommonProjectActions, including for the actions we're dealing with. Make sure the items in bold below are in the "getActions" method of the project node: @Override public Action[] getActions(boolean arg0) { return new Action[]{ CommonProjectActions.newFileAction(), CommonProjectActions.copyProjectAction(), CommonProjectActions.moveProjectAction(), CommonProjectActions.renameProjectAction(), CommonProjectActions.deleteProjectAction(), CommonProjectActions.customizeProjectAction(), CommonProjectActions.closeProjectAction() }; } Run the Application. When you run the application, you should see this: Let's now try out the various actions: Copy. When you invoke the Copy action, you'll see the dialog below. Provide a new project name and location and then the copy action is performed when the Copy button is clicked below: The message you see above, in red, might not be relevant to your project type. When you right-click the application and choose Branding, you can find the string in the Resource Bundles tab, as shown below: However, note that the message will be shown in red, no matter what the text is, hence you can really only put something like a warning message there. If you have no text at all, it will also look odd.If the project has subprojects, the copy operation will not automatically copy the subprojects. Take a look here and here for similar more complex scenarios. Move. When you invoke the Move action, the dialog below is shown: Rename. The Rename Project dialog below is shown when you invoke the Rename action: I tried it and both the display name and the folder on disk are changed. Delete. When you invoke the Delete action, you'll see this dialog: The checkbox is not checkable, in the default scenario, and when the dialog above is confirmed, the project is simply closed, i.e., the node hierarchy is removed from the application. However, if you truly want to let the user delete the project on disk, pass the Project to the DeleteOperationImplementation and then add the children of the Project you want to delete to the getDataFiles method: private final class CustomerProjectDeleteOperation implements DeleteOperationImplementation { private final CustomerProject project; private CustomerProjectDeleteOperation(CustomerProject project) { this.project = project; } @Override public List<FileObject> getDataFiles() { List<FileObject> files = new ArrayList<FileObject>(); FileObject[] projectChildren = project.getProjectDirectory().getChildren(); for (FileObject fileObject : projectChildren) { addFile(project.getProjectDirectory(), fileObject.getNameExt(), files); } return files; } private void addFile(FileObject projectDirectory, String fileName, List<FileObject> result) { FileObject file = projectDirectory.getFileObject(fileName); if (file != null) { result.add(file); } } @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyDeleting() throws IOException { } @Override public void notifyDeleted() throws IOException { } } Now the user will be able to check the checkbox, causing the method above to be called in the DeleteOperationImplementation: Hope this answers some questions or at least gets the discussion started. Before asking questions about this topic, please take the steps above and only then attempt to apply them to your own scenario. Useful implementations to look at: http://kickjava.com/src/org/netbeans/modules/j2ee/clientproject/AppClientProjectOperations.java.htm https://kenai.com/projects/nbandroid/sources/mercurial/content/project/src/org/netbeans/modules/android/project/AndroidProjectOperations.java

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• Session Evaluations

  - by BuckWoody

  I do a lot of public speaking. I write, teach, present and communicate at many levels. I love to do those things. And I love to get better at them. And one of the ways you get better at something is to get feedback on how you did. That being said, I have to confess that I really despise the “evaluations” I get at most venues. From college to technical events to other locations, at Microsoft and points in between, I find these things to be just shy of damaging, and most certainly useless. And it’s not always your fault. Ouch. That seems harsh. But let me ask you one question – and be as honest as you can with the answer – think about it first: “What is the point of a session evaluation?” I’m not saying there isn’t one. In fact, I think there’s a really important reason for them. In my mind, it’s really this: To make the speaker / next session better. Now, if you look at that, you can see right away that most session evals don’t accomplish this goal – not even a little. No, the way that they are worded and the way you (and I) fill them out, it’s more like the implied goal is this: Tell us how you liked this speaker / session. The current ones are for you, not for the speaker or the next person. It’s a popularity contest. Don’t get me wrong. I want to you have a good time. I want you to learn. I want (desperately, oh, please oh please) for you to like me. But in fact, that’s probably not why you went to the session / took the class / read that post. No, you want to learn, and to learn for a particular reason. Remember, I’m talking about college classes, sessions and other class environments here, not a general public event. Most – OK, all – session evaluations make you answer the second goal, not the first. Let’s see how: First, they don’t ask you why you’re there. They don’t ask you if you’re even qualified to evaluate the session or speaker. They don’t ask you how to make it better or keep it great. They use odd numeric scales that are meaningless. For instance, can someone really tell me the difference between a 100-level session and a 200-level one? Between a 400-level and a 500? Is it “internals” (whatever that means) or detail, or length or code, or what? I once heard a great description: A 100-level session makes me say, “wow - I’m smart.” A 500-level session makes me say “wow – that presenter is smart.” And just what is the difference between a 6 and a 7 answer on this question: How well did the speaker know the material? 1  2  3  4  5  6  7  8  9  10 Oh. My. Gosh. How does that make the next session better, or the speaker? And what criteria did you use to answer? And is a “10” better than a “1” (not always clear, and various cultures answer this differently). When it’s all said and done, a speaker basically finds out one thing from the current session evals: “They liked me. They really really liked me.” Or, “Wow. I think I may need to schedule some counseling for the depression I’m about to go into.” You may not think that’s what the speaker hears, but trust me, they do. Those are the only two reactions to the current feedback sheets they get. Either they keep doing what they are doing, or they get their feelings hurt. They just can’t use the information provided to do better. Sorry, but there it is. Keep in mind I do want your feedback. I want to get better. I want you to get your money and time’s worth, probably as much as any speaker alive. But I want those evaluations to be accurate, specific and actionable. I want to know if you had a good time, sure, but I also want to know if I did the right things, and if not, if I can do something different or better. And so, for your consideration, here is the evaluation form I would LOVE for you to use. Feel free to copy it and mail it to me any time. I’m going to put some questions here, and then I’ll even include why they are there. Notice that the form asks you a subjective question right away, and then makes you explain why. That’s work on your part. Notice also that it separates the room and the coffee and the lights and the LiveMeeting from the presenter. So many presenters are faced with circumstances beyond their control, and yet are rated high or low personally on those things. This form helps tease those apart. It’s not numeric. Numbers are easier for the scoring committees but are useless for you and me. So I don’t have any numbers. We’re actually going to have to read these things, not put them in a machine. Hey, if you put in the work to write stuff down, the least we could do is take the time to read it. It’s not anonymous. If you’ve got something to say, say it, and own up to it. People are not “more honest” when they are anonymous, they are less honest. So put your name on it. In fact – this is radical – I posit that these evaluations should be publicly available. Forever. Just like replies to a blog post. Hey, if I’m an organizer, I would LOVE to be able to have access to specific, actionable information on the attendees and the speakers. So if you want mine to be public, go for it. I’ll take the good and the bad. Enjoy. ------------------------------------------------------------------------------------------------------------------------------------------- Session Evaluation – Date, Time, Location, Topic Thanks for giving us your time today. We know that’s valuable, and we hope you learned something you can use from the session. If you can answer these questions as completely as you can, it will help the next person who attends a session here. Your Name: What you do for a living: (We Need your background to evaluate your evaluation) How long you have been doing that: (Again, we need your background to evaluate your evaluation) Paste Session Description Here: (This is what I said I would talk about) Did you like the session?                     No        Meh        Yes (General subjective question – overall “feeling”. You’ll tell us why in a minute.)  Tell us about the venue. Temperature, lights, coffee, or the online sound, performance, anything other than the speaker and the material. (Helps the logistics to be better or as good for the next person) 1. What did you expect to learn in this session? (How did you interpret that extract – did you have expectations that I should work towards for the next person?) 2. Did you learn what you expected to learn? Why? Be very specific. (This is the most important question there is. It tells us how to make the session better for someone like you.) 3. If you were giving this presentation, would you have done anything differently? What? (Helps us to gauge you, the listener, and might give us a great idea on how to do something better. Thanks!) 4. What will you do with the information you got? (Every presenter wants you to learn, and learn something useful. This will help us do that as well or better)  

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• Java Program help [migrated]

  - by georgetheevilman

  Okay I have a really annoying error. Its coming from my retainAll method. The problem is that I am outputting 1,3,5 in ints at the end, but I need 1,3,5,7,9. Here is the code below for the MySet and driver classes public class MySetTester { public static void main(String[]args) { MySet<String> strings = new MySet<String>(); strings.add("Hey!"); strings.add("Hey!"); strings.add("Hey!"); strings.add("Hey!"); strings.add("Hey!"); strings.add("Listen!"); strings.add("Listen!"); strings.add("Sorry, I couldn't resist."); strings.add("Sorry, I couldn't resist."); strings.add("(you know you would if you could)"); System.out.println("Testing add:\n"); System.out.println("Your size: " + strings.size() + ", contains(Sorry): " + strings.contains("Sorry, I couldn't resist.")); System.out.println("Exp. size: 4, contains(Sorry): true\n"); MySet<String> moreStrings = new MySet<String>(); moreStrings.add("Sorry, I couldn't resist."); moreStrings.add("(you know you would if you could)"); strings.removeAll(moreStrings); System.out.println("Testing remove and removeAll:\n"); System.out.println("Your size: " + strings.size() + ", contains(Sorry): " + strings.contains("Sorry, I couldn't resist.")); System.out.println("Exp. size: 2, contains(Sorry): false\n"); MySet<Integer> ints = new MySet<Integer>(); for (int i = 0; i < 100; i++) { ints.add(i); } System.out.println("Your size: " + ints.size()); System.out.println("Exp. size: 100\n"); for (int i = 0; i < 100; i += 2) { ints.remove(i); } System.out.println("Your size: " + ints.size()); System.out.println("Exp. size: 50\n"); MySet<Integer> zeroThroughNine = new MySet<Integer>(); for (int i = 0; i < 10; i++) { zeroThroughNine.add(i); } ints.retainAll(zeroThroughNine); System.out.println("ints should now only retain odd numbers" + " 0 through 10\n"); System.out.println("Testing your iterator:\n"); for (Integer i : ints) { System.out.println(i); } System.out.println("\nExpected: \n\n1 \n3 \n5 \n7 \n9\n"); System.out.println("Yours:"); for (String s : strings) { System.out.println(s); } System.out.println("\nExpected: \nHey! \nListen!"); strings.clear(); System.out.println("\nClearing your set...\n"); System.out.println("Your set is empty: " + strings.isEmpty()); System.out.println("Exp. set is empty: true"); } } And here is the main code. But still read the top part because that's where my examples are. import java.util.Set; import java.util.Collection; import java.lang.Iterable; import java.util.Iterator; import java.util.Arrays; import java.lang.reflect.Array; public class MySet implements Set, Iterable { // instance variables - replace the example below with your own private E[] backingArray; private int numElements; /** * Constructor for objects of class MySet */ public MySet() { backingArray=(E[]) new Object[5]; numElements=0; } public boolean add(E e){ for(Object elem:backingArray){ if (elem==null ? e==null : elem.equals(e)){ return false; } } if(numElements==backingArray.length){ E[] newArray=Arrays.copyOf(backingArray,backingArray.length*2); newArray[numElements]=e; numElements=numElements+1; backingArray=newArray; return true; } else{ backingArray[numElements]=e; numElements=numElements+1; return true; } } public boolean addAll(Collection<? extends E> c){ for(E elem:c){ this.add(elem); } return true; } public void clear(){ E[] newArray=(E[])new Object[backingArray.length]; numElements=0; backingArray=newArray; } public boolean equals(Object o){ if(o instanceof Set &&(((Set)o).size()==numElements)){ for(E elem:(Set<E>)o){ if (this.contains(o)==false){ return false; } return true; } } return false; } public boolean contains(Object o){ for(E backingElem:backingArray){ if (o!=null && o.equals(backingElem)){ return true; } } return false; } public boolean containsAll(Collection<?> c){ for(E elem:(Set<E>)c){ if(!(this.contains(elem))){ return false; } } return true; } public int hashCode(){ int sum=0; for(E elem:backingArray){ if(elem!=null){ sum=sum+elem.hashCode(); } } return sum; } public boolean isEmpty(){ if(numElements==0){ return true; } else{ return false; } } public boolean remove(Object o){ int i=0; for(Object elem:backingArray){ if(o!=null && o.equals(elem)){ backingArray[i]=null; numElements=numElements-1; E[] newArray=Arrays.copyOf(backingArray,backingArray.length-1); return true; } i=i+1; } return false; } public boolean removeAll(Collection<?> c){ for(Object elem:c){ this.remove(elem); } return true; } public boolean retainAll(Collection<?> c){ MySet<E> removalArray=new MySet<E>(); for(E arrayElem:backingArray){ if(arrayElem!= null && !(c.contains(arrayElem))){ this.remove(arrayElem); } } return false; } public int size(){ return numElements; } public <T> T[] toArray(T[] a) throws ArrayStoreException,NullPointerException{ for(int i=0;i<numElements;i++){ a[i]=(T)backingArray[i]; } for(int j=numElements;j<a.length;j++){ a[j]=null; } return a; } public Object[] toArray(){ Object[] newArray=new Object[numElements]; for(int i=0;i<numElements;i++){ newArray[i]=backingArray[i]; } return newArray; } public Iterator<E> iterator(){ setIterator iterator=new setIterator(); return iterator; } private class setIterator implements Iterator<E>{ private int currIndex; private E lastElement; public setIterator(){ currIndex=0; lastElement=null; } public boolean hasNext(){ while(currIndex<=numElements && backingArray[currIndex]==null){ currIndex=currIndex+1; } if (currIndex<=numElements){ return true; } return false; } public E next(){ E element=backingArray[currIndex]; currIndex=currIndex+1; lastElement=element; return element; } public void remove() throws UnsupportedOperationException,IllegalStateException{ if(lastElement!=null){ MySet.this.remove((Object)lastElement); numElements=numElements-1; } else{ throw new IllegalStateException(); } } } } I've been able to reduce the problems, but otherwise this thing is still causing problems.

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• How to export SSIS to Microsoft Excel without additional software?

  - by Dr. Zim

  This question is long winded because I have been updating the question over a very long time trying to get SSIS to properly export Excel data. I managed to solve this issue, although not correctly. Aside from someone providing a correct answer, the solution listed in this question is not terrible. The only answer I found was to create a single row named range wide enough for my columns. In the named range put sample data and hide it. SSIS appends the data and reads metadata from the single row (that is close enough for it to drop stuff in it). The data takes the format of the hidden single row. This allows headers, etc. WOW what a pain in the butt. It will take over 450 days of exports to recover the time lost. However, I still love SSIS and will continue to use it because it is still way better than Filemaker LOL. My next attempt will be doing the same thing in the report server. Original question notes: If you are in Sql Server Integrations Services designer and want to export data to an Excel file starting on something other than the first line, lets say the forth line, how do you specify this? I tried going in to the Excel Destination of the Data Flow, changed the AccessMode to OpenRowSet from Variable, then set the variable to "YPlatters$A4:I20000" This fails saying it cannot find the sheet. The sheet is called YPlatters. I thought you could specify (Sheet$)(Starting Cell):(Ending Cell)? Update Apparently in Excel you can select a set of cells and name them with the name box. This allows you to select the name instead of the sheet without the $ dollar sign. Oddly enough, whatever the range you specify, it appends the data to the next row after the range. Oddly, as you add data, it increases the named selection's row count. Another odd thing is the data takes the format of the last line of the range specified. My header rows are bold. If I specify a range that ends with the header row, the data appends to the row below, and makes all the entries bold. if you specify one row lower, it puts a blank line between the header row and the data, but the data is not bold. Another update No matter what I try, SSIS samples the "first row" of the file and sets the metadata according to what it finds. However, if you have sample data that has a value of zero but is formatted as the first row, it treats that column as text and inserts numeric values with a single quote in front ('123.34). I also tried headers that do not reflect the data types of the columns. I tried changing the metadata of the Excel destination, but it always changes it back when I run the project, then fails saying it will truncate data. If I tell it to ignore errors, it imports everything except that column. Several days of several hours a piece later... Another update I tried every combination. A mostly working example is to create the named range starting with the column headers. Format your column headers as you want the data to look as the data takes on this format. In my example, these exist from A4 to E4, which is my defined range. SSIS appends to the row after the defined range, so defining A4 to E68 appends the rows starting at A69. You define the Connection as having the first row contains the field names. It takes on the metadata of the header row, oddly, not the second row, and it guesses at the data type, not the formatted data type of the column, i.e., headers are text, so all my metadata is text. If your headers are bold, so is all of your data. I even tried making a sample data row without success... I don't think anyone actually uses Excel with the default MS SSIS export. If you could define the "insert range" (A5 to E5) with no header row and format those columns (currency, not bold, etc.) without it skipping a row in Excel, this would be very helpful. From what I gather, noone uses SSIS to export Excel without a third party connection manager. Any ideas on how to set this up properly so that data is formatted correctly, i.e., the metadata read from Excel is proper to the real data, and formatting inherits from the first row of data, not the headers in Excel? One last update (July 17, 2009) I got this to work very well. One thing I added to Excel was the IMEX=1 in the Excel connection string: "Excel 8.0;HDR=Yes;IMEX=1". This forces Excel (I think) to look at all rows to see what kind of data is in it. Generally, this does not drop information, say for instance if you have a zip code then about 9 rows down you have a zip+4, Excel without this blanks that field entirely without error. With IMEX=1, it recognizes that Zip is actually a character field instead of numeric. And of course, one more update (August 27, 2009) The IMEX=1 will succeed importing data with missing contents in the first 8 rows, but it will fail exporting data where no data exists. So, have it on your import connection string, but not your export Excel connection string. I have to say, after so much fiddling, it works pretty well.

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• How do I rotate only some views when working with a uinavigationcontroller as a tab of a uitabbarcon

  - by maxpower

  Here is a flow that I can not figure out how to work. ( when I state (working) it means that in that current state the rules for orientation for that view are working correctly) First View: TableView on the stack of a UINavigationController that is a tab of UITabBarController. TableView is only allowed to be portrait. (working) When you rotate the TableView to landscape a modal comes up with a custom UIView that is like a coverflow (which i'll explain the problem there in a moment). A Selection made on tableview pushes a UIScrollview on to the stack. UIScrollView is allowed all orientations. (working) When UIScrollView is in landscape mode and the user hits back they are taken to the custom UIView that is like the coverflow and only allows landscape. The problem is here. Because the UIScrollView allows full rotation it permitted the TableView to rotate as well to landscape. I have a method attached to a notification "UIDeviceOrientationDidChangeNotification" that checks to see if the custom view is the current controller and if it is and if the user has rotated back to portrait I need to pop the custom view and show the table view. The table view has to rotate back to portrait, which really is okay as long as the user doesn't see it. When I create custom animations it works pretty good except for some odd invisible black box that seems to rotate with the device right before I fade out the customview to the tableview. Further inorder to ensure that my tableview will rotate to portrait I have to allow the customview to support all orientations because the system looks to the current view (in my code) as to whether or not that app is allowed to rotate to a certain orientation. Because of this I many proposed solutions will show the customview rotating to portrait as the table view comes back to focus. My other problem is very similar. If you are viewing the tableview and rotate the modalview of the customview is presented. When you make a selection on this view it pushes the UIScrollview onto the stack, but because the Tableview only supports portrait the UIScrollview comes in in portrait while the device is in landscape mode. How can I overcome these awful blocks? This is my current attempt: When it comes to working with UITabBarController the system really only cares what the tabbarcontroller has to say about rotation. Currently whenever a view loads it reports it supported orientations. TabBarController.m - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { switch (self.supportedOrientation) { case SupportPortraitOrientation: [[UIApplication sharedApplication] setStatusBarHidden:NO animated:YES]; return (interfaceOrientation == UIInterfaceOrientationPortrait); break; case SupportPortraitUpsideDownOrientation: [[UIApplication sharedApplication] setStatusBarHidden:NO animated:YES]; return (interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown); break; case SupportPortraitAllOrientation: [[UIApplication sharedApplication] setStatusBarHidden:NO animated:YES]; return (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown); break; case SupportLandscapeLeftOrientation: [[UIApplication sharedApplication] setStatusBarHidden:YES animated:YES]; return (interfaceOrientation == UIInterfaceOrientationLandscapeLeft); break; case SupportLandscapeRightOrienation: [[UIApplication sharedApplication] setStatusBarHidden:YES animated:YES]; return (interfaceOrientation == UIInterfaceOrientationLandscapeRight); break; case SupportLandscapeAllOrientation: [[UIApplication sharedApplication] setStatusBarHidden:YES animated:YES]; return (interfaceOrientation == UIInterfaceOrientationLandscapeLeft || interfaceOrientation == UIInterfaceOrientationLandscapeRight); break; case SupportAllOrientation: if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft || interfaceOrientation == UIInterfaceOrientationLandscapeRight) { [[UIApplication sharedApplication] setStatusBarHidden:YES animated:YES]; }else { //[[UIApplication sharedApplication] setStatusBarHidden:NO animated:YES]; } return YES; break; default: return (interfaceOrientation == UIInterfaceOrientationPortrait); break; } } This block of code is part of my UINavigationController and is in a method that responds to the UIDeviceOrientationDidChangeNotification Notification. It is responsible for poping the customview and showing the tableview. There are two different versions in place that originally were for two different versions of the SDK but both are pretty close to solutions. The reason the first is not supported on 3.0 is for some reason you can't have a view showing and then showen as a modal view. Not sure if that is a bug or a feature. The second solution works pretty good except that I see an outer box rotating around the iphone. if ([[self topViewController] isKindOfClass:FlowViewController.class]) { NSString *iphoneVersion = [[UIDevice currentDevice] systemVersion]; double version = [iphoneVersion doubleValue]; if(version > 3.0){ //1st solution //if the delivered app is not built with the 3.1 SDK I don't think this will happen anyway //we need to test this [self presentModalViewController:self.flowViewController animated:NO]; //[self toInterfaceOrientation:UIDeviceOrientationPortrait animated:NO]; [self popViewControllerAnimated:NO]; [self setNavigationBarHidden:NO animated:NO]; [self dismissModalViewControllerAnimated:YES]; }else{ //2nd solution DLog(@"3.0!!"); //[self toInterfaceOrientation:UIDeviceOrientationPortrait animated:NO]; CATransition *transition = [CATransition animation]; transition.duration = 0.50; transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; transition.type = kCATransitionPush; transition.subtype = kCATransitionFade; CATransition *tabBarControllerLayer = [CATransition animation]; tabBarControllerLayer.duration = 0.50; tabBarControllerLayer.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; tabBarControllerLayer.type = kCATransitionPush; tabBarControllerLayer.subtype = kCATransitionFade; [self.tabBarController.view.layer addAnimation:transition forKey:kCATransition]; [self.view.layer addAnimation:transition forKey:kCATransition]; [self popViewControllerAnimated:NO]; [self setNavigationBarHidden:NO animated:NO]; } [self performSelector:@selector(resetFlow) withObject:nil afterDelay:0.75]; } I'm near convinced there is no solution except for manual rotation which messes up the keyboard rotation. Any advice would be appreciated! Thanks.

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• SQL CLR Assembly Error 80131051 when late binding to a registered C# COM .dll

  - by Shanubus

  I must have hit an unusual one, because I can't find any reference to this specific failing anywhere... Scenario: I have a legacy SQL function used to transform(encrypt) data. This function is called from within many stored procedures used by multiple applications. I say this, because the obvious answer of 'just call it from your code' is not really an option (or at least one I'd prefer not explore). The legacy function used sp_OA with an ActiveX dll on SQL2000 to perform its work. The new function is targeted at SQL2008 x64. I am ditching the sp_OA call in favor of CLR assembly; and am getting rid of the ActiveX dll and using a COM+ .dll (3rd party) to perform the same work. This 3rd party COM+ is required to be used based on spec given to me, so can't get rid of this piece either. Problem: After multiple attempts at getting this to work I have eliminated the following approaches 1) Create a Sql Assembly to call the local COM+ directly -- Can't do this as it requires a reference to System.EnterpriseServices. Including this requires that a whole slew of unsupported assemblies be registered which I don't want. The COM+ requires it's methods to be accessed via an Interface, so my attempts at late binding to it directly have not been successful (late binding would allow me to drop the unsupported references). 2) Create a Sql Assembly which references a C# class library that then calls the COM+. -- Same issue as #1; since the referenced dll uses System.EnterpriseServices and will be added as a dependency when referenced in the Sql Assembly, again trying to load all the unsupported libraries 3) Create a Sql Assembly which late binds to an ActiveX COM dll that calls the COM+. -- Worked in my dev environment, but can't go to x64 in production with ActiveX dll's written in VB6 (not to mention I hate backtracking anyway)... again failure... I am now onto an approach that is almost working, with of course one last hangup. I now have -a Sql Assembly that late binds to a C# COM dll, eliminating the need for including System.EnterpriseServices and eliminating the need to reference the C# COM in the SqlAssembly itself. The C# COM does reference System.EnterpriseServices to call the COM+, but since I am late binding to it from the SqlAssembly, I bypass the need for Sql to actually load them as referenced assemblies. Works in debugger.. Works on my dev box when the SqlAssembly dll is referenced in a test console app and called directly Installs to Sql2008 just fine Executing the actual UDF works, but returns no data due to a failure reporting from the late bound dll! So the SqlAssembly is instanciated just fine. It actually fails on it's late binding to the C# COM, which is working from a test console app on the same machine. It appears to be a difference in behavior based on whether called from within the SQL UDF or not. Since it is working on the same box from my console app, I am assuming it's on the SQL side. My steps to install were. --Install the COM+ dll and ensure it can be called successfully (as from with in the console app) --Register the C# COM dll (which calls the COM+) and get it to the GAC (again proofed to be working from console app) --Create my Assymetric Key CREATE ASYMMETRIC KEY SqlCryptoKey FROM EXECUTABLE FILE = 'D:\SqlEx.dll' CREATE LOGIN SqlExLogin FROM ASYMMETRIC KEY SqlExKey GRANT UNSAFE ASSEMBLY TO SqlExLogin GO --Add the assembly CREATE ASSEMBLY SqlEx FROM 'D:\SqlEx.dll' WITH PERMISSION_SET = UNSAFE; GO --Create the function CREATE FUNCTION dbo.f_SqlEx( @clearText [nvarchar](512) ) RETURNS nvarchar(512) WITH EXECUTE AS CALLER AS EXTERNAL NAME SqlEx.[SqlEx.SqlEx].Ex GO With all that done, I can now call my function SELECT dbo.f_SqlEx('test') But get this error in the event log... Retrieving the COM class factory for component with CLSID {F69D6320-5884-323F-936A-7657946604BE} failed due to the following error: 80131051. I can't really provide direct code examples, due to internal security implications; but all the code itself seems to work, I am suspecting perms or something of the like... I just find it odd that I can't find any reference to error 80131051. If someone out there believe some 'indirect' code samples will help, I will be happy to provide. Any assistance is appreciated.

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• JQuery tablesorter - Keeping grouped subheaders together, but still sorted

  - by hfidgen

  Hiya, I'm not really a Javascript programmer, so I'm struggling with this! I'm using the tablesorter plugin along with the Tablegroup plugin, which work very nicely to group the table rows by a parent, and then sort the parents. My problem is though, that I'd also like the child rows to be sorted whilst within the parent group I've done my best to get this working but I'm afraid I've hit a wall. Can anyone suggest a new starter for 10? The example below is working fine - There are 2x groups here: Nordics (Norway and Denmark) DACH (Germany and Austria) If I click on the header row, the groups are sorted, but the child rows within the group are not sorted. <script type="text/javascript"> $(document).ready(function () { $(".tablesorter") .tablesorter({ // set default sort column sortList: [[0,0]], // don't sort by first column headers: {0: {sorter: false}} , onRenderHeader: function (){ this.wrapInner("<span></span>"); } , debug: true }) }); </script> <table id="results-header" class="grid tablesorter table-header" cellpadding="0" cellspacing="0" border="0"> <thead> <tr class="title"> <th class="countries">&nbsp;</th> <th>% market share</th> <th>% increase in mkt share</th> <th>Target achieved</th> <th>% targets</th> <th>% sales inc. M-o-M</th> <th>% sales inc. M-o-M for country</th> <th>% training</th> </tr> </thead> <tbody> <tr id="Nord" class="collapsible parent parent-even collapsed"> <td class="countries">Nordics</td> <td>39.5</td> <td>49</td> <td>69.8</td> <td>51.8</td> <td>43</td> <td>42.5</td> <td>38</td> </tr> <tr id="row-Norway" class="expand-child child child-Nord"> <td class="countries">Norway</td> <td>6</td> <td>45</td> <td>101</td> <td>10</td> <td>20</td> <td>40</td> <td>30</td> </tr> <tr id="row-Denmark" class="expand-child child child-Nord"> <td class="countries">Denmark</td> <td>10</td> <td>20</td> <td>3</td> <td>40</td> <td>50</td> <td>25</td> <td>8</td> </tr> <tr id="DACH" class="collapsible parent parent-odd collapsed"> <td class="countries">DACH</td> <td>77</td> <td>61</td> <td>43</td> <td>98</td> <td>65</td> <td>92.5</td> <td>59.5</td> </tr> <tr id="row-Germany" class="expand-child child child-DACH"> <td class="countries">Germany</td> <td>56</td> <td>24</td> <td>84</td> <td>98</td> <td>32</td> <td>87</td> <td>21</td> </tr> <tr id="row-Austria" class="expand-child child child-DACH"> <td class="countries">Austria</td> <td>98</td> <td>98</td> <td>2</td> <td>98</td> <td>98</td> <td>98</td> <td>98</td> </tr> </tbody> </table>

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• Why won't my UISearchDisplayController fire the didSelectRowAtIndexPath moethod?

  - by John Wells

  I am having an odd problem when searching a UITableView using a UISearchDisplayController. The UITableViewController is a subclass of another UITableViewController with a working didSelectRowAtIndexPath method. Without searching the controller handles selections fine, sending the superclass a didSelectRowAtIndexPath call, but if I select a cell when searching the superclass receives nothing but the cell is highlighted. Below is the code from my subclass. @implementation AdvancedViewController @synthesize searchDisplayController, dict, filteredList; - (void)viewDidLoad { [super viewDidLoad]; // Programmatically set up search bar UISearchBar *mySearchBar = [[UISearchBar alloc] init]; mySearchBar.delegate = self; [mySearchBar setAutocapitalizationType:UITextAutocapitalizationTypeNone]; [mySearchBar sizeToFit]; self.tableView.tableHeaderView = mySearchBar; // Programmatically set up search display controller searchDisplayController = [[UISearchDisplayController alloc] initWithSearchBar:mySearchBar contentsController:self]; [self setSearchDisplayController:searchDisplayController]; [searchDisplayController setDelegate:self]; [searchDisplayController setSearchResultsDataSource:self]; // Parse data from server NSData * jsonData = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]]; NSArray * items = [[NSArray alloc] initWithArray:[[CJSONDeserializer deserializer] deserializeAsArray:jsonData error:nil]]; // Init variables dict = [[NSMutableDictionary alloc] init]; listIndex = [[NSMutableArray alloc] init]; fullList = [[NSMutableArray alloc] init]; filteredList = [[NSMutableArray alloc] init]; // Get each item and format it for the UI for(NSMutableArray * item in items) { // Get the first letter NSString * firstKey = [[[item objectAtIndex:0] substringWithRange:NSMakeRange(0,1)] uppercaseString]; // Put symbols and numbers in the same section if ([[firstKey stringByTrimmingCharactersInSet:[[NSCharacterSet letterCharacterSet] invertedSet]] isEqualToString:@""]) firstKey = @"#"; // If there isn't a section with this key if (![listIndex containsObject:firstKey]) { // Add the key to the index for faster access (because it's already sorted) [listIndex addObject:firstKey]; // Add the key to the unordered dictionary [dict setObject:[NSMutableArray array] forKey:firstKey]; } // Add the object to the dictionary [[dict objectForKey:firstKey] addObject:[[NSMutableDictionary alloc] initWithObjects:item forKeys:[NSArray arrayWithObjects:@"name", @"url", nil]]]; // Add the object to the list for simple searching [fullList addObject:[[NSMutableDictionary alloc] initWithObjects:item forKeys:[NSArray arrayWithObjects:@"name", @"url", nil]]]; } filteredList = [NSMutableArray arrayWithCapacity:[fullList count]]; } #pragma mark - #pragma mark Table view data source // Custom method for object oriented data access - (NSString *)tableView:(UITableView *)tableView dataForRowAtIndexPath:(NSIndexPath *)indexPath withKey:(NSString *)key { return (NSString *)((tableView == self.searchDisplayController.searchResultsTableView) ? [[filteredList objectAtIndex:indexPath.row] objectForKey:key] : [[[dict objectForKey:[listIndex objectAtIndex:indexPath.section]] objectAtIndex:indexPath.row] valueForKey:key]); } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return (tableView == self.searchDisplayController.searchResultsTableView) ? 1 : (([listIndex count] > 0) ? [[dict allKeys] count] : 1); } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return (tableView == self.searchDisplayController.searchResultsTableView) ? [filteredList count] : [[dict objectForKey:[listIndex objectAtIndex:section]] count]; } - (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView { return (tableView == self.searchDisplayController.searchResultsTableView) ? [[NSArray alloc] initWithObjects:nil] : listIndex; } - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { return (tableView == self.searchDisplayController.searchResultsTableView) ? @"" : [listIndex objectAtIndex:section]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *kCellID = @"cellID"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kCellID]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:kCellID] autorelease]; cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; } NSString * name = nil; // TODO: Make dataForRowAtIndexPath work here if (tableView == self.searchDisplayController.searchResultsTableView) { // NOTE: dataForRowAtIndexPath causes this to crash for some unknown reason. Maybe it is called before viewDidLoad and has no data? name = [[filteredList objectAtIndex:indexPath.row] objectForKey:@"name"]; } else { // This always works name = [self tableView:[self tableView] dataForRowAtIndexPath:indexPath withKey:@"name"]; } cell.textLabel.text = name; return cell; } #pragma mark Search Methods - (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope { // Clear the filtered array [self.filteredList removeAllObjects]; // Filter the array for (NSDictionary *item in fullList) { // Compare the item's name to the search text NSComparisonResult result = [[item objectForKey:@"name"] compare:searchText options:(NSCaseInsensitiveSearch|NSDiacriticInsensitiveSearch) range:NSMakeRange(0, [searchText length])]; if (result == NSOrderedSame) { // Add to the filtered array if it matches [self.filteredList addObject:item]; } } } - (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString { [self filterContentForSearchText:searchString scope: [[self.searchDisplayController.searchBar scopeButtonTitles] objectAtIndex:[self.searchDisplayController.searchBar selectedScopeButtonIndex]]]; // Return YES to cause the search result table view to be reloaded. return YES; } - (void)viewDidUnload { filteredList = nil; } @end

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• qemu-kvm virtual machine virtio network freeze under load

  - by Rick Koshi

  I'm having a problem with my virtual machines, where the network will freeze under heavy load. I'm using CentOS 6.2 as both host and guest, not using libvirt, just running qemu-kvm directly as follows: /usr/libexec/qemu-kvm \ -drive file=/data2/vm/rb-dev2-www1-vm.img,index=0,media=disk,cache=none,if=virtio \ -boot order=c \ -m 2G \ -smp cores=1,threads=2 \ -vga std \ -name rb-dev2-www1-vm \ -vnc :84,password \ -net nic,vlan=0,macaddr=52:54:20:00:00:54,model=virtio \ -net tap,vlan=0,ifname=tap84,script=/etc/qemu-ifup \ -monitor unix:/var/run/vm/rb-dev2-www1-vm.mon,server,nowait \ -rtc base=utc \ -device piix3-usb-uhci \ -device usb-tablet /etc/qemu-ifup (used by the above command) is a very simple script, containing the following: #!/bin/sh sudo /sbin/ifconfig $1 0.0.0.0 promisc up sudo /usr/sbin/brctl addif br0 $1 sleep 2 And here's the info on br0 and other interfaces: avl-host3 14# brctl show bridge name bridge id STP enabled interfaces br0 8000.180373f5521a no bond0 tap84 virbr0 8000.525400858961 yes virbr0-nic avl-host3 15# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: em1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc mq master bond0 state UP qlen 1000 link/ether 18:03:73:f5:52:1a brd ff:ff:ff:ff:ff:ff 3: em2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc mq master bond0 state UP qlen 1000 link/ether 18:03:73:f5:52:1a brd ff:ff:ff:ff:ff:ff 4: em3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 18:03:73:f5:52:1e brd ff:ff:ff:ff:ff:ff 5: em4: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 18:03:73:f5:52:20 brd ff:ff:ff:ff:ff:ff 6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP link/ether 18:03:73:f5:52:1a brd ff:ff:ff:ff:ff:ff inet6 fe80::1a03:73ff:fef5:521a/64 scope link valid_lft forever preferred_lft forever 7: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN link/ether 18:03:73:f5:52:1a brd ff:ff:ff:ff:ff:ff inet 172.16.1.46/24 brd 172.16.1.255 scope global br0 inet6 fe80::1a03:73ff:fef5:521a/64 scope link valid_lft forever preferred_lft forever 8: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN link/ether 52:54:00:85:89:61 brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 9: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 500 link/ether 52:54:00:85:89:61 brd ff:ff:ff:ff:ff:ff 12: tap84: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500 link/ether ba:e8:9b:2a:ff:48 brd ff:ff:ff:ff:ff:ff inet6 fe80::b8e8:9bff:fe2a:ff48/64 scope link valid_lft forever preferred_lft forever bond0 is a bond of em1 and em2. virbr0 and virbr0-nic are vestigial interfaces left over from CentOS's default installation. They are unused (as far as I know). The guest runs perfectly until I run a large 'rsync', when the network will freeze after some seemingly-random time (usually under a minute). When it freezes, there is no network activity in or out of the guest. I can still connect to the guest's console via vnc, but it is unable to speak out its network interface. Any attempt to 'ping' from the guest gives a "Destination Host Unreachable" error for 3/4 packets and no reply for every fourth packet. Sometimes (perhaps two thirds of the time), I can bring the interface back to life by doing a "service network restart" from the guest's console. If this works (and if I do it before the rsync times out), the rsync will resume. Usually it will freeze again within a minute or two. If I repeat, the rsync will eventually finish, and I presume the machine goes back to waiting for another period of heavy load. Throughout the whole process, there are no console errors or relevant (that I can see) syslog messages on either guest or host machine. If the "service network restart" doesn't work the first time, trying again (and again and again) never seems to work. The command completes normally, with normal output, but the interface stays frozen. However, a soft reboot of the guest machine (without restarting qemu-kvm) always seems to bring it back. I am aware of the "lowest mac address" assignment problem, where the bridge takes on the mac address of the slave interface with the lowest mac address. This causes temporary network freezes, but is definitely not what's happening for me. My freezes are permanent until manual intervention, and you can see from the 'ip addr show' output above that the mac address being used by br0 is that of the physical ethernet. There are no other virtual machines running on the host. I've verified that each virtual machine on the subnet has its own unique mac address. I have rebuilt the guest machine several times, and I have tried this on three different host machines (identical hardware, built identically). Oddly, I do have one virtual host (the second of this series) which never seemed to have a problem. It never had its network freeze when it was running the same rsync during its build. It's particularly odd because it was the second build. The first, on a different host, did have the freezing problem, but the second did not. I assumed at the time that I had done something wrong with the first build, and that the problem was resolved. Unfortunately, the problem reappeared when I built the third VM. Also unfortunately, I can't do many tests with the working VM, as it's now in production use, and I'm hoping I can find the cause of this issue before that machine starts having problems. It's possible that I just got really lucky while running the rsync on the working machine, and that one time it didn't freeze. Of course it's possible that I somehow changed the build scripts without realizing it and re-broke something, but I can't find any such thing. In any case, I'm hoping someone has some idea what could cause this. Addendum: Preliminary tests suggest that I don't have the problem if I substitute e1000 for virtio in the first -net flag to qemu-kvm. I don't consider this a solution, but it is suitable for a stopgap. Has anyone else had (or better yet, solved) this problem with the virtio network driver?

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• NFS issue brings down entire vSphere ESX estate

  - by growse

  I experienced an odd issue this morning where an NFS issue appeared to have taken down the majority of my VMs hosted on a small vSphere 5.0 estate. The infrastructure itself is 4x IBM HS21 blades running around 20 VMs. The storage is provided by a single HP X1600 array with attached D2700 chassis running Solaris 11. There's a couple of storage pools on this which are exposed over NFS for the storage of the VM files, and some iSCSI LUNs for things like MSCS shared disks. Normally, this is pretty stable, but I appreciate the lack of resiliancy in having a single X1600 doing all the storage. This morning, in the logs of each ESX host, at around 0521 GMT I saw a lot of entries like this: 2011-11-30T05:21:54.161Z cpu2:2050)NFSLock: 608: Stop accessing fd 0x41000a4cf9a8 3 2011-11-30T05:21:54.161Z cpu2:2050)NFSLock: 608: Stop accessing fd 0x41000a4dc9e8 3 2011-11-30T05:21:54.161Z cpu2:2050)NFSLock: 608: Stop accessing fd 0x41000a4d3fa8 3 2011-11-30T05:21:54.161Z cpu2:2050)NFSLock: 608: Stop accessing fd 0x41000a4de0a8 3 [....] 2011-11-30T06:16:07.042Z cpu0:2058)WARNING: NFS: 283: Lost connection to the server 10.13.111.197 mount point /sastank/VMStorage, mounted as f0342e1c-19be66b5-0000-000000000000 ("SAStank") 2011-11-30T06:17:01.459Z cpu2:4011)NFS: 292: Restored connection to the server 10.13.111.197 mount point /sastank/VMStorage, mounted as f0342e1c-19be66b5-0000-000000000000 ("SAStank") 2011-11-30T06:25:17.887Z cpu3:2051)NFSLock: 608: Stop accessing fd 0x41000a4c2b28 3 2011-11-30T06:27:16.063Z cpu3:4011)NFSLock: 568: Start accessing fd 0x41000a4d8928 again 2011-11-30T06:35:30.827Z cpu1:2058)WARNING: NFS: 283: Lost connection to the server 10.13.111.197 mount point /tank/ISO, mounted as 5acdbb3e-410e56e3-0000-000000000000 ("ISO (1)") 2011-11-30T06:36:37.953Z cpu6:2054)NFS: 292: Restored connection to the server 10.13.111.197 mount point /tank/ISO, mounted as 5acdbb3e-410e56e3-0000-000000000000 ("ISO (1)") 2011-11-30T06:40:08.242Z cpu6:2054)NFSLock: 608: Stop accessing fd 0x41000a4c3e68 3 2011-11-30T06:40:34.647Z cpu3:2051)NFSLock: 568: Start accessing fd 0x41000a4d8928 again 2011-11-30T06:44:42.663Z cpu1:2058)WARNING: NFS: 283: Lost connection to the server 10.13.111.197 mount point /sastank/VMStorage, mounted as f0342e1c-19be66b5-0000-000000000000 ("SAStank") 2011-11-30T06:44:53.973Z cpu0:4011)NFS: 292: Restored connection to the server 10.13.111.197 mount point /sastank/VMStorage, mounted as f0342e1c-19be66b5-0000-000000000000 ("SAStank") 2011-11-30T06:51:28.296Z cpu5:2058)NFSLock: 608: Stop accessing fd 0x41000ae3c528 3 2011-11-30T06:51:44.024Z cpu4:2052)NFSLock: 568: Start accessing fd 0x41000ae3b8e8 again 2011-11-30T06:56:30.758Z cpu4:2058)WARNING: NFS: 283: Lost connection to the server 10.13.111.197 mount point /sastank/VMStorage, mounted as f0342e1c-19be66b5-0000-000000000000 ("SAStank") 2011-11-30T06:56:53.389Z cpu7:2055)NFS: 292: Restored connection to the server 10.13.111.197 mount point /sastank/VMStorage, mounted as f0342e1c-19be66b5-0000-000000000000 ("SAStank") 2011-11-30T07:01:50.350Z cpu6:2054)ScsiDeviceIO: 2316: Cmd(0x41240072bc80) 0x12, CmdSN 0x9803 to dev "naa.600508e000000000505c16815a36c50d" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x5 0x24 0x0. 2011-11-30T07:03:48.449Z cpu3:2051)NFSLock: 608: Stop accessing fd 0x41000ae46b68 3 2011-11-30T07:03:57.318Z cpu4:4009)NFSLock: 568: Start accessing fd 0x41000ae48228 again (I've put a complete dump from one of the hosts on pastebin: http://pastebin.com/Vn60wgTt) When I got in the office at 9am, I saw various failures and alarms and troubleshooted the issue. It turned out that pretty much all of the VMs were inaccessible, and that the ESX hosts either were describing each VM as 'powered off', 'powered on', or 'unavailable'. The VMs described as 'powered on' where not in any way reachable or responding to pings, so this may be lies. There's absolutely no indication on the X1600 that anything was awry, and nothing on the switches to indicate any loss of connectivity. I only managed to resolve the issue by rebooting the ESX hosts in turn. I have a number of questions: What the hell happened? If this was a temporary NFS failure, why did it put the ESX hosts into a state from which a reboot was the only recovery? In the future, when the NFS server goes a little off-piste, what would be the best approach to add some resilience? I've been looking at budgeting for next year and potentially have budget to purchase another X1600/D2700/disks, would an identical mirrored disk setup help to mitigate these sorts of failures automatically? Edit (Added requested details) To expand with some details as requested: The X1600 has 12x 1TB disks lumped together in mirrored pairs as tank, and the D2700 (connected with a mini SAS cable) has 12x 300GB 10k SAS disks lumped together in mirrored pairs as sastank zpool status pool: rpool state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM rpool ONLINE 0 0 0 c7t0d0s0 ONLINE 0 0 0 errors: No known data errors pool: sastank state: ONLINE scan: scrub repaired 0 in 74h21m with 0 errors on Wed Nov 30 02:51:58 2011 config: NAME STATE READ WRITE CKSUM sastank ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c7t14d0 ONLINE 0 0 0 c7t15d0 ONLINE 0 0 0 mirror-1 ONLINE 0 0 0 c7t16d0 ONLINE 0 0 0 c7t17d0 ONLINE 0 0 0 mirror-2 ONLINE 0 0 0 c7t18d0 ONLINE 0 0 0 c7t19d0 ONLINE 0 0 0 mirror-3 ONLINE 0 0 0 c7t20d0 ONLINE 0 0 0 c7t21d0 ONLINE 0 0 0 mirror-4 ONLINE 0 0 0 c7t22d0 ONLINE 0 0 0 c7t23d0 ONLINE 0 0 0 mirror-5 ONLINE 0 0 0 c7t24d0 ONLINE 0 0 0 c7t25d0 ONLINE 0 0 0 errors: No known data errors pool: tank state: ONLINE scan: scrub repaired 0 in 17h28m with 0 errors on Mon Nov 28 17:58:19 2011 config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c7t1d0 ONLINE 0 0 0 c7t2d0 ONLINE 0 0 0 mirror-1 ONLINE 0 0 0 c7t3d0 ONLINE 0 0 0 c7t4d0 ONLINE 0 0 0 mirror-2 ONLINE 0 0 0 c7t5d0 ONLINE 0 0 0 c7t6d0 ONLINE 0 0 0 mirror-3 ONLINE 0 0 0 c7t8d0 ONLINE 0 0 0 c7t9d0 ONLINE 0 0 0 mirror-4 ONLINE 0 0 0 c7t10d0 ONLINE 0 0 0 c7t11d0 ONLINE 0 0 0 mirror-5 ONLINE 0 0 0 c7t12d0 ONLINE 0 0 0 c7t13d0 ONLINE 0 0 0 errors: No known data errors The filesystem exposed over NFS for the primary datastore is sastank/VMStorage zfs list NAME USED AVAIL REFER MOUNTPOINT rpool 45.1G 13.4G 92.5K /rpool rpool/ROOT 2.28G 13.4G 31K legacy rpool/ROOT/solaris 2.28G 13.4G 2.19G / rpool/dump 15.0G 13.4G 15.0G - rpool/export 11.9G 13.4G 32K /export rpool/export/home 11.9G 13.4G 32K /export/home rpool/export/home/andrew 11.9G 13.4G 11.9G /export/home/andrew rpool/swap 15.9G 29.2G 123M - sastank 1.08T 536G 33K /sastank sastank/VMStorage 1.01T 536G 1.01T /sastank/VMStorage sastank/comstar 71.7G 536G 31K /sastank/comstar sastank/comstar/sql_tempdb 6.31G 536G 6.31G - sastank/comstar/sql_tx_data 65.4G 536G 65.4G - tank 4.79T 578G 42K /tank tank/FTP 269G 578G 269G /tank/FTP tank/ISO 28.8G 578G 25.9G /tank/ISO tank/backupstage 2.64T 578G 2.49T /tank/backupstage tank/cifs 301G 578G 297G /tank/cifs tank/comstar 1.54T 578G 31K /tank/comstar tank/comstar/msdtc 1.07G 579G 32.8M - tank/comstar/quorum 577M 578G 47.9M - tank/comstar/sqldata 1.54T 886G 304G - tank/comstar/vsphere_lun 2.09G 580G 22.2M - tank/mcs-asset-repository 7.01M 578G 6.99M /tank/mcs-asset-repository tank/mscs-quorum 55K 578G 36K /tank/mscs-quorum tank/sccm 16.1G 578G 12.8G /tank/sccm As for the networking, all connections between the X1600, the Blades and the switch are either LACP or Etherchannel bonded 2x 1Gbit links. Switch is a single Cisco 3750. Storage traffic sits on its own VLAN segregated from VM machine traffic.

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• NSStream sockets missing data

  - by Chris T.

  I am trying to pull some sample data from FreeDB as a proof of concept, but I am having a tough time retrieving all of the data off the incoming stream (I am only getting the last bits for the final query listed here (if handshakeCode = 3) I think this may be something with the threading on the main runloop, but I am not sure. Odd thing is when the buffer size is larger than 1-2 bytes (which works as expected), I seem to be losing access to the data programmatically (the totalOutput variable on the first set of data is incomplete). I set up a packet capture, and it looks like those 1024 bytes are coming across the wire, but the app just isn't working with it. It looks like the next event is coming through and basically taking over. I tried using an NSLock to no avail as well. If I drop the buffer size down to 1 or 2, things seem to be reading just fine. This is probably obvious to someone who does this all the time, but this is my first foray into this with something I am familiar with, technology wise in other languages / platforms. The following code will show you what is happening. Run with the buffer set to 1024, and you will see a short final string, but once you set it to 1, you will see the amount of data I was expecting (I was even expecting it to be split, so that's not a big worry) #import <Foundation/Foundation.h> #import <Cocoa/Cocoa.h> //STACK OVERFLOW CODE: @interface stackoverflow : NSObject <NSStreamDelegate> { NSInputStream *iStream; NSOutputStream *oStream; int handshakeCode; NSString *selectedDiscId; NSString *selectedGenre; } -(void)getMatchesFromFreeDB; -(void)sendToOutputStream:(NSString*)command; @end @implementation stackoverflow -(void)getMatchesFromFreeDB { NSHost *host = [NSHost hostWithName:@"freedb.freedb.org"]; [NSStream getStreamsToHost:host port:8880 inputStream:&iStream outputStream:&oStream]; [iStream retain]; [oStream retain]; [iStream setDelegate:self]; [oStream setDelegate:self]; [iStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [oStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [iStream open]; [oStream open]; handshakeCode = 0; //not done any processing } -(void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode { switch(eventCode) { case NSStreamEventOpenCompleted: { NSLog(@"Stream open completed"); break; } case NSStreamEventHasBytesAvailable: { NSLog(@"Stream has bytes available"); if (aStream == iStream) { NSMutableString *totalOutput = [NSMutableString stringWithString:@""]; //read data uint8_t buffer[1024]; int len; while ([iStream hasBytesAvailable]) { len = [iStream read:buffer maxLength:sizeof(buffer)]; if (len 0) { NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSUTF8StringEncoding]; //this could have also been put into an NSData object if (nil != output) { //append to the total output [totalOutput appendString:output]; } } } NSLog(@"OUTPUT , %i:\n\n%@", [totalOutput lengthOfBytesUsingEncoding:NSUTF8StringEncoding], totalOutput); NSArray *outputComponents = [totalOutput componentsSeparatedByString:@" "]; //Attempt to get handshake code, since we haven't done it yet: if (handshakeCode == 1) { //we are just getting the sign-on banner: //let's move on: handshakeCode = 2; } else if (handshakeCode == 2) { handshakeCode = [[outputComponents objectAtIndex:0] intValue]; if (handshakeCode == 200) { NSLog(@"---Handshake OK %i", handshakeCode); NSMutableString *query = [NSMutableString stringWithString:@"cddb query f3114b11 17 225 19915 36489 54850 69425 87025 103948 123242 136075 152817 178335 192850 211677 235104 262090 284882 308658 4430\n"]; handshakeCode = 3; [self sendToOutputStream:query]; } } else if (handshakeCode == 3) { //now, we are reading out the matches: if ([[outputComponents objectAtIndex:0] intValue] == 200) //found exact match: { NSLog(@"Found exact match"); selectedGenre = [outputComponents objectAtIndex:1] ; selectedDiscId = [outputComponents objectAtIndex:2]; if (selectedGenre && selectedDiscId) { //send off the request to get the entry: NSString *query = [NSString stringWithFormat:@"cddb read %@ %@\n", selectedGenre, selectedDiscId]; [self sendToOutputStream:query]; handshakeCode = 4; } } } } break; } case NSStreamEventEndEncountered: { NSLog(@"Stream event end encountered"); break; } case NSStreamEventErrorOccurred: { NSLog(@"Stream error occurred"); break; } case NSStreamEventHasSpaceAvailable: { NSLog(@"Stream has space available"); if (aStream == oStream) { if (handshakeCode == 0) { handshakeCode = 1; [self sendToOutputStream:@"cddb hello stackoverflow localhost.localdomain test .01BETA\n"]; } } break; } } } -(void)sendToOutputStream:(NSString*)command { const uint8_t *rawCommand = (const uint8_t *)[command UTF8String]; [oStream write:rawCommand maxLength:strlen(rawCommand)]; NSLog(@"Sent command: %@",command); } @end int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; stackoverflow *test = [[stackoverflow alloc] init]; [test getMatchesFromFreeDB]; NSRunLoop *runLoop = [NSRunLoop currentRunLoop]; [runLoop run]; [pool drain]; return 0; } Any help is much appreciated! Thanks

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• Graphics.MeasureCharacterRanges giving wrong size calculations in C#.Net?

  - by Owen Blacker

  I'm trying to render some text into a specific part of an image in a Web Forms app. The text will be user entered, so I want to vary the font size to make sure it fits within the bounding box. I have code that was doing this fine on my proof-of-concept implementation, but I'm now trying it against the assets from the designer, which are larger, and I'm getting some odd results. I'm running the size calculation as follows: StringFormat fmt = new StringFormat(); fmt.Alignment = StringAlignment.Center; fmt.LineAlignment = StringAlignment.Near; fmt.FormatFlags = StringFormatFlags.NoClip; fmt.Trimming = StringTrimming.None; int size = __startingSize; Font font = __fonts.GetFontBySize(size); while (GetStringBounds(text, font, fmt).IsLargerThan(__textBoundingBox)) { context.Trace.Write("MyHandler.ProcessRequest", "Decrementing font size to " + size + ", as size is " + GetStringBounds(text, font, fmt).Size() + " and limit is " + __textBoundingBox.Size()); size--; if (size < __minimumSize) { break; } font = __fonts.GetFontBySize(size); } context.Trace.Write("MyHandler.ProcessRequest", "Writing " + text + " in " + font.FontFamily.Name + " at " + font.SizeInPoints + "pt, size is " + GetStringBounds(text, font, fmt).Size() + " and limit is " + __textBoundingBox.Size()); I then use the following line to render the text onto an image I'm pulling from the filesystem: g.DrawString(text, font, __brush, __textBoundingBox, fmt); where: __fonts is a PrivateFontCollection, PrivateFontCollection.GetFontBySize is an extension method that returns a FontFamily RectangleF __textBoundingBox = new RectangleF(150, 110, 212, 64); int __minimumSize = 8; int __startingSize = 48; Brush __brush = Brushes.White; int size starts out at 48 and decrements within that loop Graphics g has SmoothingMode.AntiAlias and TextRenderingHint.AntiAlias set context is a System.Web.HttpContext (this is an excerpt from the ProcessRequest method of an IHttpHandler) The other methods are: private static RectangleF GetStringBounds(string text, Font font, StringFormat fmt) { CharacterRange[] range = { new CharacterRange(0, text.Length) }; StringFormat myFormat = fmt.Clone() as StringFormat; myFormat.SetMeasurableCharacterRanges(range); using (Graphics g = Graphics.FromImage(new Bitmap( (int) __textBoundingBox.Width - 1, (int) __textBoundingBox.Height - 1))) { g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias; g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias; Region[] regions = g.MeasureCharacterRanges(text, font, __textBoundingBox, myFormat); return regions[0].GetBounds(g); } } public static string Size(this RectangleF rect) { return rect.Width + "×" + rect.Height; } public static bool IsLargerThan(this RectangleF a, RectangleF b) { return (a.Width > b.Width) || (a.Height > b.Height); } Now I have two problems. Firstly, the text sometimes insists on wrapping by inserting a line-break within a word, when it should just fail to fit and cause the while loop to decrement again. I can't see why it is that Graphics.MeasureCharacterRanges thinks that this fits within the box when it shouldn't be word-wrapping within a word. This behaviour is exhibited irrespective of the character set used (I get it in Latin alphabet words, as well as other parts of the Unicode range, like Cyrillic, Greek, Georgian and Armenian). Is there some setting I should be using to force Graphics.MeasureCharacterRanges only to be word-wrapping at whitespace characters (or hyphens)? This first problem is the same as post 2499067. Secondly, in scaling up to the new image and font size, Graphics.MeasureCharacterRanges is giving me heights that are wildly off. The RectangleF I am drawing within corresponds to a visually apparent area of the image, so I can easily see when the text is being decremented more than is necessary. Yet when I pass it some text, the GetBounds call is giving me a height that is almost double what it's actually taking. Using trial and error to set the __minimumSize to force an exit from the while loop, I can see that 24pt text fits within the bounding box, yet Graphics.MeasureCharacterRanges is reporting that the height of that text, once rendered to the image, is 122px (when the bounding box is 64px tall and it fits within that box). Indeed, without forcing the matter, the while loop iterates to 18pt, at which point Graphics.MeasureCharacterRanges returns a value that fits. The trace log excerpt is as follows: Decrementing font size to 24, as size is 193×122 and limit is 212×64 Decrementing font size to 23, as size is 191×117 and limit is 212×64 Decrementing font size to 22, as size is 200×75 and limit is 212×64 Decrementing font size to 21, as size is 192×71 and limit is 212×64 Decrementing font size to 20, as size is 198×68 and limit is 212×64 Decrementing font size to 19, as size is 185×65 and limit is 212×64 Writing VENNEGOOR of HESSELINK in DIN-Black at 18pt, size is 178×61 and limit is 212×64 So why is Graphics.MeasureCharacterRanges giving me a wrong result? I could understand it being, say, the line height of the font if the loop stopped around 21pt (which would visually fit, if I screenshot the results and measure it in Paint.Net), but it's going far further than it should be doing because, frankly, it's returning the wrong damn results. Any and all help gratefully received. Thanks!

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• Repeated Squaring - Matrix Multiplication using NEWMAT

  - by Dinakar Kulkarni

  I'm trying to use the repeated squaring algorithm (using recursion) to perform matrix exponentiation. I've included header files from the NEWMAT library instead of using arrays. The original matrix has elements in the range (-5,5), all numbers being of type float. # include "C:\User\newmat10\newmat.h" # include "C:\User\newmat10\newmatio.h" # include "C:\User\newmat10\newmatap.h" # include <iostream> # include <time.h> # include <ctime> # include <cstdlib> # include <iomanip> using namespace std; Matrix repeated_squaring(Matrix A, int exponent, int n) //Recursive function { A(n,n); IdentityMatrix I(n); if (exponent == 0) //Matrix raised to zero returns an Identity Matrix return I; else { if ( exponent%2 == 1 ) // if exponent is odd return (A * repeated_squaring (A*A, (exponent-1)/2, n)); else //if exponent is even return (A * repeated_squaring( A*A, exponent/2, n)); } } Matrix direct_squaring(Matrix B, int k, int no) //Brute Force Multiplication { B(no,no); Matrix C = B; for (int i = 1; i <= k; i++) C = B*C; return C; } //----Creating a matrix with elements b/w (-5,5)---- float unifRandom() { int a = -5; int b = 5; float temp = (float)((b-a)*( rand()/RAND_MAX) + a); return temp; } Matrix initialize_mat(Matrix H, int ord) { H(ord,ord); for (int y = 1; y <= ord; y++) for(int z = 1; z<= ord; z++) H(y,z) = unifRandom(); return(H); } //--------------------------------------------------- void main() { int exponent, dimension; cout<<"Insert exponent:"<<endl; cin>>exponent; cout<< "Insert dimension:"<<endl; cin>>dimension; cout<<"The number of rows/columns in the square matrix is: "<<dimension<<endl; cout<<"The exponent is: "<<exponent<<endl; Matrix A(dimension,dimension),B(dimension,dimension); Matrix C(dimension,dimension),D(dimension,dimension); B= initialize_mat(A,dimension); cout<<"Initial Matrix: "<<endl; cout<<setw(5)<<setprecision(2)<<B<<endl; //----------------------------------------------------------------------------- cout<<"Repeated Squaring Result: "<<endl; clock_t time_before1 = clock(); C = repeated_squaring (B, exponent , dimension); cout<< setw(5) <<setprecision(2) <<C; clock_t time_after1 = clock(); float diff1 = ((float) time_after1 - (float) time_before1); cout << "It took " << diff1/CLOCKS_PER_SEC << " seconds to complete" << endl<<endl; //--------------------------------------------------------------------------------- cout<<"Direct Squaring Result:"<<endl; clock_t time_before2 = clock(); D = direct_squaring (B, exponent , dimension); cout<<setw(5)<<setprecision(2)<<D; clock_t time_after2 = clock(); float diff2 = ((float) time_after2 - (float) time_before2); cout << "It took " << diff2/CLOCKS_PER_SEC << " seconds to complete" << endl<<endl; } I face the following problems: The random number generator returns only "-5" as each element in the output. The Matrix multiplication yield different results with brute force multiplication and using the repeated squaring algorithm. I'm timing the execution time of my code to compare the times taken by brute force multiplication and by repeated squaring. Could someone please find out what's wrong with the recursion and with the matrix initialization? NOTE: While compiling this program, make sure you've imported the NEWMAT library. Thanks in advance!

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• Getting a NullPointerException at seemingly random intervals, not sure why

  - by Miles

  I'm running an example from a Kinect library for Processing (http://www.shiffman.net/2010/11/14/kinect-and-processing/) and sometimes get a NullPointerException pointing to this line: int rawDepth = depth[offset]; The depth array is created in this line: int[] depth = kinect.getRawDepth(); I'm not exactly sure what a NullPointerException is, and much googling hasn't really helped. It seems odd to me that the code compiles 70% of the time and returns the error unpredictably. Could the hardware itself be affecting it? Here's the whole example if it helps: // Daniel Shiffman // Kinect Point Cloud example // http://www.shiffman.net // https://github.com/shiffman/libfreenect/tree/master/wrappers/java/processing import org.openkinect.*; import org.openkinect.processing.*; // Kinect Library object Kinect kinect; float a = 0; // Size of kinect image int w = 640; int h = 480; // We'll use a lookup table so that we don't have to repeat the math over and over float[] depthLookUp = new float[2048]; void setup() { size(800,600,P3D); kinect = new Kinect(this); kinect.start(); kinect.enableDepth(true); // We don't need the grayscale image in this example // so this makes it more efficient kinect.processDepthImage(false); // Lookup table for all possible depth values (0 - 2047) for (int i = 0; i < depthLookUp.length; i++) { depthLookUp[i] = rawDepthToMeters(i); } } void draw() { background(0); fill(255); textMode(SCREEN); text("Kinect FR: " + (int)kinect.getDepthFPS() + "\nProcessing FR: " + (int)frameRate,10,16); // Get the raw depth as array of integers int[] depth = kinect.getRawDepth(); // We're just going to calculate and draw every 4th pixel (equivalent of 160x120) int skip = 4; // Translate and rotate translate(width/2,height/2,-50); rotateY(a); for(int x=0; x<w; x+=skip) { for(int y=0; y<h; y+=skip) { int offset = x+y*w; // Convert kinect data to world xyz coordinate int rawDepth = depth[offset]; PVector v = depthToWorld(x,y,rawDepth); stroke(255); pushMatrix(); // Scale up by 200 float factor = 200; translate(v.x*factor,v.y*factor,factor-v.z*factor); // Draw a point point(0,0); popMatrix(); } } // Rotate a += 0.015f; } // These functions come from: http://graphics.stanford.edu/~mdfisher/Kinect.html float rawDepthToMeters(int depthValue) { if (depthValue < 2047) { return (float)(1.0 / ((double)(depthValue) * -0.0030711016 + 3.3309495161)); } return 0.0f; } PVector depthToWorld(int x, int y, int depthValue) { final double fx_d = 1.0 / 5.9421434211923247e+02; final double fy_d = 1.0 / 5.9104053696870778e+02; final double cx_d = 3.3930780975300314e+02; final double cy_d = 2.4273913761751615e+02; PVector result = new PVector(); double depth = depthLookUp[depthValue];//rawDepthToMeters(depthValue); result.x = (float)((x - cx_d) * depth * fx_d); result.y = (float)((y - cy_d) * depth * fy_d); result.z = (float)(depth); return result; } void stop() { kinect.quit(); super.stop(); } And here are the errors: processing.app.debug.RunnerException: NullPointerException at processing.app.Sketch.placeException(Sketch.java:1543) at processing.app.debug.Runner.findException(Runner.java:583) at processing.app.debug.Runner.reportException(Runner.java:558) at processing.app.debug.Runner.exception(Runner.java:498) at processing.app.debug.EventThread.exceptionEvent(EventThread.java:367) at processing.app.debug.EventThread.handleEvent(EventThread.java:255) at processing.app.debug.EventThread.run(EventThread.java:89) Exception in thread "Animation Thread" java.lang.NullPointerException at org.openkinect.processing.Kinect.enableDepth(Kinect.java:70) at PointCloud.setup(PointCloud.java:48) at processing.core.PApplet.handleDraw(PApplet.java:1583) at processing.core.PApplet.run(PApplet.java:1503) at java.lang.Thread.run(Thread.java:637)

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• Factorising program not working. Help required.

  - by Ender

  I am working on a factorisation problem using Fermat's Factorization and for small numbers it is working well. I've been able to calculate the factors (getting the answers from Wolfram Alpha) for small numbers, like the one on the Wikipedia page (5959). Just when I thought I had the problem licked I soon realised that my program was not working when it came to larger numbers. The program follows through the examples from the Wikipedia page, printing out the values a, b, a2 and b2; the results printed for large numbers are not correct. I've followed the pseudocode provided on the Wikipedia page, but am struggling to understand where to go next. Along with the Wikipedia page I have been following this guide. Once again, as my Math knowledge is pretty poor I cannot follow what I need to do next. The code I am using so far is as follows: import java.math.BigInteger; /** * * @author AlexT */ public class Fermat { private BigInteger a, b; private BigInteger b2; private static final BigInteger TWO = BigInteger.valueOf(2); public void fermat(BigInteger N) { // floor(sqrt(N)) BigInteger tmp = getIntSqrt(N); // a <- ceil(sqrt(N)) a = tmp.add(BigInteger.ONE); // b2 <- a*a-N b2 = (a.multiply(a)).subtract(N); final int bitLength = N.bitLength(); BigInteger root = BigInteger.ONE.shiftLeft(bitLength / 2); root = root.add(b2.divide(root)).divide(TWO); // while b2 not square root while(!(isSqrt(b2, root))) { // a <- a + 1 a = a.add(BigInteger.ONE); // b2 <- (a * a) - N b2 = (a.multiply(a)).subtract(N); root = root.add(b2.divide(root)).divide(TWO); } b = getIntSqrt(b2); BigInteger a2 = a.pow(2); // Wrong BigInteger sum = (a.subtract(b)).multiply((a.add(b))); //if(sum.compareTo(N) == 0) { System.out.println("A: " + a + "\nB: " + b); System.out.println("A^2: " + a2 + "\nB^2: " + b2); //} } /** * Is the number provided a perfect Square Root? * @param n * @param root * @return */ private static boolean isSqrt(BigInteger n, BigInteger root) { final BigInteger lowerBound = root.pow(2); final BigInteger upperBound = root.add(BigInteger.ONE).pow(2); return lowerBound.compareTo(n) <= 0 && n.compareTo(upperBound) < 0; } public BigInteger getIntSqrt(BigInteger x) { // It returns s where s^2 < x < (s+1)^2 BigInteger s; // final result BigInteger currentRes = BigInteger.valueOf(0); // init value is 0 BigInteger currentSum = BigInteger.valueOf(0); // init value is 0 BigInteger sum = BigInteger.valueOf(0); String xS = x.toString(); // change input x to a string xS int lengthOfxS = xS.length(); int currentTwoBits; int i=0; // index if(lengthOfxS % 2 != 0) {// if odd length, add a dummy bit xS = "0".concat(xS); // add 0 to the front of string xS lengthOfxS++; } while(i < lengthOfxS){ // go through xS two by two, left to right currentTwoBits = Integer.valueOf(xS.substring(i,i+2)); i += 2; // sum = currentSum*100 + currentTwoBits sum = currentSum.multiply(BigInteger.valueOf(100)); sum = sum.add(BigInteger.valueOf(currentTwoBits)); // subtraction loop do { currentSum = sum; // remember the value before subtract // in next 3 lines, we work out // currentRes = sum - 2*currentRes - 1 sum = sum.subtract(currentRes); // currentRes++ currentRes = currentRes.add(BigInteger.valueOf(1)); sum = sum.subtract(currentRes); } while(sum.compareTo(BigInteger.valueOf(0)) >= 0); // the loop stops when sum < 0 // go one step back currentRes = currentRes.subtract(BigInteger.valueOf(1)); currentRes = currentRes.multiply(BigInteger.valueOf(10)); } s = currentRes.divide(BigInteger.valueOf(10)); // go one step back return s; } /** * @param args the command line arguments */ public static void main(String[] args) { Fermat fermat = new Fermat(); //Works //fermat.fermat(new BigInteger("5959")); // Doesn't Work fermat.fermat(new BigInteger("90283")); } } If anyone can help me out with this problem I'll be eternally grateful.

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