Search Results

Search found 1591 results on 64 pages for 'implementations'.

Page 57/64 | < Previous Page | 53 54 55 56 57 58 59 60 61 62 63 64  | Next Page >

• C++ Class Access Specifier Verbosity

  - by PolyTex

  A "traditional" C++ class (just some random declarations) might resemble the following: class Foo { public: Foo(); explicit Foo(const std::string&); ~Foo(); enum FooState { Idle, Busy, Unknown }; FooState GetState() const; bool GetBar() const; void SetBaz(int); private: struct FooPartialImpl; void HelperFunction1(); void HelperFunction2(); void HelperFunction3(); FooPartialImpl* m_impl; // smart ptr FooState m_state; bool m_bar; int m_baz; }; I always found this type of access level specification ugly and difficult to follow if the original programmer didn't organize his "access regions" neatly. Taking a look at the same snippet in a Java/C# style, we get: class Foo { public: Foo(); public: explicit Foo(const std::string&); public: ~Foo(); public: enum FooState { Idle, Busy, Unknown }; public: FooState GetState() const; public: bool GetBar() const; public: void SetBaz(int); private: struct FooPartialImpl; private: void HelperFunction1(); private: void HelperFunction2(); private: void HelperFunction3(); private: FooPartialImpl* m_impl; // smart ptr private: FooState m_state; private: bool m_bar; private: int m_baz; }; In my opinion, this is much easier to read in a header because the access specifier is right next to the target, and not a bunch of lines away. I found this especially true when working with header-only template code that wasn't separated into the usual "*.hpp/*.inl" pair. In that scenario, the size of the function implementations overpowered this small but important information. My question is simple and stems from the fact that I've never seen anyone else actively do this in their C++ code. Assuming that I don't have a "Class View" capable IDE, are there any obvious drawbacks to using this level of verbosity? Any other style recommendations are welcome!

  Read the article

• How do you programmatically set a Style on a View?

  - by Greg

  I would like to do something like this: <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_cotent" style="@style/SubmitButtonType" /> But in code The xml approach works fine provided that SubmitButtonType is defined. Now what I assume happens is that the appt parser runs through this xml, generates an AttributeSet. That AttributeSet when passed to context/theme#obtainStyledAttributes() will have the style ref mask anything that is not written inline in this tag. Great that's fine! Now how do we do this programmatically. Button, as well as other View types, has a constructor that has the form: <Widget>(Context context, AttributeSet set, int defStyle). So I thought this would work. Button button = new Button(context, null, R.style.SubmitButtonType); However, I am finding that defStyle is badly documented as it really should be written to be a resourceId to an attribute (from R.attrs) that will be passed to obtainStyledAttributes() as the attribute resource, and not the style resource. After looking at the code, all the view implementations seem to pass 0 as the styleRef. I don't see the harm in having it passed as both the attr and the style resource (more flexible and negligible overhead) However I might be approaching this all wrong. How do you do this in code then other than by setting each individual element of the style to the specific widget you want to style (only possible by looking a the code to see what param maps to which method or set of methods). The only way I have found to do this is: <declare-styleable> <attr name="totallyAdhoc_attribute_just_for_this_case" format="reference"> </declare-styleable> <style name="MyAlreadyExistantTheme" > ... ... <item name="totallyAdhoc_attribute_just_for_this_case">@style/SubmitButtonType</item> </style> And instead of passing R.style.SubmitButtonType as defStyle, I pass the new R.attr.totallyAdhoc_attribute_just_for_this_case. Button button = new Button(context, null, R.attr.totallyAdhoc_attribute_just_for_this_case); This works but sounds way too complicated.

  Read the article

• [NHibernate and ASP.NET MVC] How can I implement a robust session-per-request pattern in my project,

  - by Guillaume Gervais

  I'm currently building an ASP.NET MVC project, with NHibernate as its persistance layer. For now, some functionnalities have been implemented, but only use local NHibernate sessions: each method that accessed the database (read or write) needs to instanciate its own NHibernate session, with the "using()" directive. The problem is that I want to leverage NHibernate's Lazy-Loading capabilities to improve the performance of my project. This implies an open NHibernate session per request until the view is rendered. Furthermore, simultaneous request must be supported (multiple Sessions at the same time). How can I achieve that as cleanly as possible? I searched the Web a little bit and learned about the session-per-request pattern. Most of the implementations I saw used some sort of Http* (HttpContext, etc.) object to store the session. Also, using the Application_BeginRequest/Application_EndRequest functions is complicated, since they get fired for each HTTP request (aspx files, css files, js files, etc.), when I only want to instanciate a session once per request. The concern that I have is that I don't want my views or controllers to have access to NHibernate sessions (or, more generally, NHibernate namespaces and code). That means that I do not want to handle sessions at the controller level nor the view one. I have a few options in mind. Which one seems the best ? Use interceptors (like in GRAILS) that get triggered before and after the controller action. These would open and close sessions/transactions. Is it possible in the ASP.NET MVC world? Use the CurrentSessionContext Singleton provided by NHibernate in a Web context. Using this page as an example, I think this is quite promising, but that still requires filters at the controller level. Use the HttpContext.Current.Items to store the request session. This, coupled with a few lines of code in Global.asax.cs, can easily provide me with a session on the request level. However, it means that dependencies will be injected between NHibernate and my views (HttpContext). Thank you very much!

  Read the article

• Simplifying const Overloading?

  - by templatetypedef

  Hello all- I've been teaching a C++ programming class for many years now and one of the trickiest things to explain to students is const overloading. I commonly use the example of a vector-like class and its operator[] function: template <typename T> class Vector { public: T& operator[] (size_t index); const T& operator[] (size_t index) const; }; I have little to no trouble explaining why it is that two versions of the operator[] function are needed, but in trying to explain how to unify the two implementations together I often find myself wasting a lot of time with language arcana. The problem is that the only good, reliable way that I know how to implement one of these functions in terms of the other is with the const_cast/static_cast trick: template <typename T> const T& Vector<T>::operator[] (size_t index) const { /* ... your implementation here ... */ } template <typename T> T& Vector<T>::operator[] (size_t index) { return const_cast<T&>(static_cast<const Vector&>(*this)[index]); } The problem with this setup is that it's extremely tricky to explain and not at all intuitively obvious. When you explain it as "cast to const, then call the const version, then strip off constness" it's a little easier to understand, but the actual syntax is frightening,. Explaining what const_cast is, why it's appropriate here, and why it's almost universally inappropriate elsewhere usually takes me five to ten minutes of lecture time, and making sense of this whole expression often requires more effort than the difference between const T* and T* const. I feel that students need to know about const-overloading and how to do it without needlessly duplicating the code in the two functions, but this trick seems a bit excessive in an introductory C++ programming course. My question is this - is there a simpler way to implement const-overloaded functions in terms of one another? Or is there a simpler way of explaining this existing trick to students? Thanks so much!

  Read the article

• Using images in QListWidget, is this possible?

  - by Neko

  Hi, again. :) As with the last few times I posted here, I have a question about QT, which I am using to create a chat messenger client. To display the list of online users, I'm using a QListWidget, as created like this: listWidget = new QListWidget(horizontalLayoutWidget); listWidget->setObjectName("userList"); QSizePolicy sizePolicy1(QSizePolicy::Preferred, QSizePolicy::Expanding); sizePolicy1.setHorizontalStretch(0); sizePolicy1.setVerticalStretch(0); sizePolicy1.setHeightForWidth(listWidget->sizePolicy().hasHeightForWidth()); listWidget->setSizePolicy(sizePolicy1); listWidget->setMinimumSize(QSize(30, 0)); listWidget->setMaximumSize(QSize(150, 16777215)); listWidget->setBaseSize(QSize(100, 0)); listWidget->setContextMenuPolicy(Qt::CustomContextMenu); Users are shown by constantly refreshing the list, like this: (Note: There are different channels, with different userlists, so refreshing it is the most efficient thing to do, as far as I know.) void FMessenger::refreshUserlist() { if (currentPanel == 0) return; listWidget = this->findChild<QListWidget *>(QString("userList")); listWidget->clear(); QList<FCharacter*> charList = currentPanel->charList(); QListWidgetItem* charitem = 0; FCharacter* character; foreach(character, charList) { charitem = new QListWidgetItem(character->name()); // charitem->setIcon(QIcon(":/Images/status.png")); listWidget->addItem(charitem); } } This has always worked perfectly. The line that I commented out is the one I have problems with: my current goal is to be able to display a user's online status with an image, which represents whether they are busy, away, available, etc. Using setIcon() does absolutely nothing though, apparently; the items still show up as they used to, without icons. I'm aware that this is probably not the way this function needs to be used, but I have found little documentation about it online, and absolutely no useful examples of implementations. My question is, can anybody help me with fixing this problem? Any help would be appreciated terrifically, like always!

  Read the article

• Is a Multi-DAL Approach the way to go here?

  - by Krisc

  Working on the data access / model layer in this little MVC2 project and trying to think things out to future projects. I have a database with some basic tables and I have classes in the model layer that represent them. I obviously need something to connect the two. The easiest is to provide some sort of 'provider' that can run operations on the database and return objects. But this is for a website that would potentially be used "a lot" (I know, very general) so I want to cache results from the data layer and keep the cache updated as new data is generated. This question deals with how best to approach this problem of dual DALS. One that returns cached data when possible and goes to the data layer when there is a cache miss. But more importantly, how to integrate the core provider (thing that goes into database) with the caching layer so that it too can rely on cached objects rather than creating new ones. Right now I have the following interfaces: IDataProvider is used to reach the database. It doesn't concern itself with the meaning of the objects it produces, but simply the way to produce them. interface IDataProvider{ // Select, Update, Create, et cetera access IEnumerable<Entry> GetEntries(); Entry GetEntryById(int id); } IDataManager is a layer that sits on top of the IDataProvider layer and manages the cache interface IDataManager : IDataProvider{ void ClearCache(); } Note that in practice the IDataManager implementation will have useful helper functions to add objects to their related cache stores. (In the future I may define other functions on the interface) I guess what I am looking for is the best way to approach a loop back from the IDataProvider implementations so that they can access the cache. Or a different approach entirely may be in order? I am not very interested in 3rd party products at the moment as I am interested in the design of these things much more than this specific implementation. Edit: I realize the title may be a bit misleading. I apologize for that... not sure what to call this question.

  Read the article

• Trouble with abstract generic methods

  - by DanM

  Let's say I have a class library that defines a couple entity interfaces: public interface ISomeEntity { /* ... */ } public interface ISomeOtherEntity { /* ... */ } This library also defines an IRepository interface: public interface IRepository<TEntity> { /* ... */ } And finally, the library has an abstract class called RepositorySourceBase (see below), which the main project needs to implement. The goal of this class is to allow the base class to grab new Repository objects at runtime. Because certain repositories are needed (in this example a repository for ISomeEntity and ISomeOtherEntity), I'm trying to write generic overloads of the GetNew<TEntity>() method. The following implementation doesn't compile (the second GetNew() method gets flagged as "already defined" even though the where clause is different), but it gets at what I'm trying to accomplish: public abstract class RepositorySourceBase // This doesn't work! { public abstract Repository<TEntity> GetNew<TEntity>() where TEntity : SomeEntity; public abstract Repository<TEntity> GetNew<TEntity>() where TEntity : SomeOtherEntity; } The intended usage of this class would be something like this: public class RepositorySourceTester { public RepositorySourceTester(RepositorySourceBase repositorySource) { var someRepository = repositorySource.GetNew<ISomeEntity>(); var someOtherRepository = repositorySource.GetNew<ISomeOtherEntity>(); } } Meanwhile, over in my main project (which references the library project), I have implementations of ISomeEntity and ISomeOtherEntity: public class SomeEntity : ISomeEntity { /* ... */ } public class SomeOtherEntity : ISomeOtherEntity { /* ... */ } The main project also has an implementation for IRepository<TEntity>: public class Repository<TEntity> : IRepository<TEntity> { public Repository(string message) { } } And most importantly, it has an implementation of the abstract RepositorySourceBase: public class RepositorySource : RepositorySourceBase { public override Repository<SomeEntity> GetNew() { return new Repository<SomeEntity>("stuff only I know"); } public override Repository<SomeOtherEntity> GetNew() { return new Repository<SomeOtherEntity>("other stuff only I know"); } } Just as with RepositorySourceBase, the second GetNew() method gets flagged as "already defined". So, C# basically think I'm repeating the same method because there's no way to distinguish the methods from parameters, but if you look at my usage example, it seems like I should be able to distinguish which GetNew() I want from the generic type parameter, e.g, <ISomeEntity> or <ISomeOtherEntity>. What do I need to do to get this to work?

  Read the article

• How to properly mix generics and inheritance to get the desired result?

  - by yamsha

  My question is not easy to explain using words, fortunately it's not too difficult to demonstrate. So, bear with me: public interface Command<R> { public R execute();//parameter R is the type of object that will be returned as the result of the execution of this command } public abstract class BasicCommand<R> { } public interface CommandProcessor<C extends Command<?>> { public <R> R process(C<R> command);//this is my question... it's illegal to do, but you understand the idea behind it, right? } //constrain BasicCommandProcessor to commands that subclass BasicCommand public class BasicCommandProcessor implements CommandProcessor<C extends BasicCommand<?>> { //here, only subclasses of BasicCommand should be allowed as arguments but these //BasicCommand object should be parameterized by R, like so: BasicCommand<R> //so the method signature should really be // public <R> R process(BasicCommand<R> command) //which would break the inheritance if the interface's method signature was instead: // public <R> R process(Command<R> command); //I really hope this fully illustrates my conundrum public <R> R process(C<R> command) { return command.execute(); } } public class CommandContext { public static void main(String... args) { BasicCommandProcessor bcp = new BasicCommandProcessor(); String textResult = bcp.execute(new BasicCommand<String>() { public String execute() { return "result"; } }); Long numericResult = bcp.execute(new BasicCommand<Long>() { public Long execute() { return 123L; } }); } } Basically, I want the generic "process" method to dictate the type of generic parameter of the Command object. The goal is to be able to restrict different implementations of CommandProcessor to certain classes that implement Command interface and at the same time to able to call the process method of any class that implements the CommandProcessor interface and have it return the object of type specified by the parametarized Command object. I'm not sure if my explanation is clear enough, so please let me know if further explanation is needed. I guess, the question is "Would this be possible to do, at all?" If the answer is "No" what would be the best work-around (I thought of a couple on my own, but I'd like some fresh ideas)

  Read the article

• Is it OK to put a standard, pure C header #include directive inside a namespace?

  - by mic_e

  I've got a project with a class log in the global namespace (::log). So, naturally, after #include <cmath>, the compiler gives an error message each time I try to instantiate an object of my log class, because <cmath> pollutes the global namespace with lots of three-letter methods, one of them being the logarithm function log(). So there are three possible solutions, each having their unique ugly side-effects. Move the log class to it's own namespace and always access it with it's fully qualified name. I really want to avoid this because the logger should be as convenient as possible to use. Write a mathwrapper.cpp file which is the only file in the project that includes <cmath>, and makes all the required <cmath> functions available through wrappers in a namespace math. I don't want to use this approach because I have to write a wrapper for every single required math function, and it would add additional call penalty (cancelled out partially by the -flto compiler flag) The solution I'm currently considering: Replace #include <cmath> by namespace math { #include "math.h" } and then calculating the logarithm function via math::log(). I have tried it out and it does, indeed, compile, link and run as expected. It does, however, have multiple downsides: It's (obviously) impossible to use <cmath>, because the <cmath> code accesses the functions by their fully qualified names, and it's deprecated to use in C++. I've got a really, really bad feeling about it, like I'm gonna get attacked and eaten alive by raptors. So my question is: Is there any recommendation/convention/etc that forbid putting include directives in namespaces? Could anything go wrong with diferent C standard library implementations (I use glibc), different compilers (I use g++ 4.7, -std=c++11), linking? Have you ever tried doing this? Are there any alternate ways to banish the math functions from the global namespace? I've found several similar questions on stackoverflow, but most were about including other C++ headers, which obviously is a bad idea, and those that weren't made contradictory statements about linking behaviour for C libraries. Also, would it be beneficial to additionally put the #include <math.h> inside extern "C" {}?

  Read the article

• How dangerous is e.preventDefault();, and can it be replaced by keydown/mousedown tracking?

  - by yc

  I'm working on a tracking script for a fairly sophisticated CRM for tracking form actions in Google Analytics. I'm trying to balance the desire to track form actions accurately with the need to never prevent a form from not working. Now, I know that doing something like this doesn't work. $('form').submit(function(){ _gaq.push('_trackEvent', 'Form', 'Submit', $(this).attr('action')) }); The DOM unloads before this has a chance to process. So, a lot of sample code recommends something like this: $('form').submit(function(e){ e.preventDefault(); var form = this; _gaq.push('_trackEvent', 'Form', 'Submit', $(this).attr('action')); //...do some other tracking stuff... setTimeout(function(){ form.submit(); }, 400); }); This is reliable in most cases, but it makes me nervous. What if something happens between e.preventDefault();and when I get around to triggering the DOM based submit? I've totally broken the form. I've been poking around some other analytics implementations, and I've noticed something like this: $('form').mousedown(function(){ _gaq.push('_trackEvent', 'Form', 'Submit', $(this).attr('action')); }); $('form').keydown(function(e){ if(e.which===13) //if the keydown is the enter key _gaq.push('_trackEvent', 'Form', 'Submit', $(this).attr('action')); }); Basically, instead of interrupting the form submit, preempting it by assuming that if someone is mousing down or keying down on Enter, than that form is submitted. Obviously, this will result in a certain amount of false positives, but it completely eliminates use of e.preventDefault();, which in my mind eliminates the risk that I might ever prevent a form from successfully submitting. So, my question: Is it possible to take the standard form tracking snippet and prevent it from ever fully preventing the form from submitting? Is the mousedown/keydown alternative viable? Are there any submission cases it may miss? Specifically, are there other ways to end up submitting besides the mouse and the keyboard enter? And will the browser always have time to process javascript before beginning to unload the page?

  Read the article

• IntentService android download and return file to Activity

  - by Andrew G

  I have a fairly tricky situation that I'm trying to determine the best design for. The basics are this: I'm designing a messaging system with a similar interface to email. When a user clicks a message that has an attachment, an activity is spawned that shows the text of that message along with a paper clip signaling that there is an additional attachment. At this point, I begin preloading the attachment so that when the user clicks on it - it loads more quickly. currently, when the user clicks the attachment, it prompts with a loading dialog until the download is complete at which point it loads a separate attachment viewer activity, passing in the bmp byte array. I don't ever want to save attachments to persistent storage. The difficulty I have is in supporting rotation as well as home button presses etc. The download is currently done with a thread and handler setup. Instead of this, I'd like the flow to be the following: User loads message as before, preloading begins of attachment as before (invisible to user). When the user clicks on the attachment link, the attachment viewer activity is spawned right away. If the download was done, the image is displayed. If not, a dialog is shown in THIS activity until it is done and can be displayed. Note that ideally the download never restarts or else I've wasted cycles on the preload. Obviously I need some persistent background process that is able to keep downloading and is able to call back to arbitrarily bonded Activities. It seems like the IntentService almost fits my needs as it does its work in a background thread and has the Service (non UI) lifecycle. However, will it work for my other needs? I notice that common implementations for what I want to do get a Messenger from the caller Activity so that a Message object can be sent back to a Handler in the caller's thread. This is all well and good but what happens in my case when the caller Activity is Stopped or Destroyed and the currently active Activity (the attachment viewer) is showing? Is there some way to dynamically bind a new Activity to a running IntentService so that I can send a Message back to the new Activity? The other question is on the Message object. Can I send arbitrarily large data back in this package? For instance, rather than send back that "The file was downloaded", I need to send back the byte array of the downloaded file itself since I never want to write it to disk (and yes this needs to be the case). Any advice on achieving the behavior I want is greatly appreciated. I've not been working with Android for that long and I often get confused with how to best handle asynchronous processes over the course of the Activity lifecycle especially when it comes to orientation changes and home button presses...

  Read the article

• C# ATM Bank coding help needed please

  - by user1735692

  if anyone can help with with I would be grateful. I am trying to make a program in c# that acts like an ATM with withdrawing, depositing money, displayed in Program.cs that is connected to Account.cs linked class programs. At the moment it works if I manually input the data and tell it what to display, but I what to do is - Allow users to enter amounts to deposit and withdraw using overloaded implementations of the methods makeDeposit and makeWithdrawal. I have tried many things, and can not get it to work, if anyone can help, I would be grateful if anyone can, thanks again Program.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Tut9 { class Program { static void Main(string[] args) { Account myAcc = new Account(); myAcc.makeDeposit(10000); myAcc.showBalance(); Console.WriteLine("Attempting to withdraw £" + 90); myAcc.makeWithdrawal(90); myAcc.showBalance(); myAcc.giveOverdraft(50); myAcc.showBalance(); Account student = new Account(30, -100); student.giveOverdraft(-500); } } } Account.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Tut9 { class Account { ////Need to know the balance & ovedraft private int balance; private int overdraft; ////Constructor public Account() { balance = 0; overdraft = 0; } public Account(int initial) { balance = initial; } public Account(int intial, int over) { balance = intial; overdraft = over; } public void giveOverdraft(int amount) { overdraft = amount; } ////Method to display the balance & overdraft public void showBalance() { Console.WriteLine("The balance is now £" + balance); if (overdraft != 0) { Console.WriteLine("You have an overdraft of £" + overdraft); } } ////Method to make a withdrawl public void makeWithdrawal(int y) { balance = balance - y; Console.WriteLine("Withdrew £" + y); } ////Method to make deposit public void makeDeposit(int x) { balance = balance + x; Console.WriteLine("Desposited £" + x); } } }

  Read the article

• C# Different class objects in one list

  - by jeah_wicer

  I have looked around some now to find a solution to this problem. I found several ways that could solve it but to be honest I didn't realize which of the ways that would be considered the "right" C# or OOP way of solving it. My goal is not only to solve the problems but also to develop a good set of code standards and I'm fairly sure there's a standard way to handle this problem. Let's say I have 2 types of printer hardwares with their respective classes and ways of communicating: PrinterType1, PrinterType2. I would also like to be able to later on add another type if neccessary. One step up in abstraction those have much in common. It should be possible to send a string to each one of them as an example. They both have variables in common and variables unique to each class. (One for instance communicates via COM-port and has such an object, while the other one communicates via TCP and has such an object). I would however like to just implement a List of all those printers and be able to go through the list and perform things as "Send(string message)" on all Printers regardless of type. I would also like to access variables like "PrinterList[0].Name" that are the same for both objects, however I would also at some places like to access data that is specific to the object itself (For instance in the settings window of the application where the COM-port name is set for one object and the IP/port number for another). So, in short something like: In common: Name Send() Specific to PrinterType1: Port Specific to PrinterType2: IP And I wish to, for instance, do Send() on all objects regardless of type and the number of objects present. I've read about polymorphism, Generics, interfaces and such, but I would like to know how this, in my eyes basic, problem typically would be dealt with in C# (and/or OOP in general). I actually did try to make a base class, but it didn't quite seem right to me. For instance I have no use of a "string Send(string Message)" function in the base class itself. So why would I define one there that needs to be overridden in the derived classes when I would never use the function in the base class ever in the first place? I'm really thankful for any answers. People around here seem very knowledgeable and this place has provided me with many solutions earlier. Now I finally have an account to answer and vote with too. EDIT: To additionally explain, I would also like to be able to access the objects of the actual printertype. For instance the Port variable in PrinterType1 which is a SerialPort object. I would like to access it like: PrinterList[0].Port.Open() and have access to the full range of functionality of the underlaying port. At the same time I would like to call generic functions that work in the same way for the different objects (but with different implementations): foreach (printer in Printers) printer.Send(message)

  Read the article

• Abstract class and an inheritor: is it possible to factorize .parent() here?

  - by fge

  Here are what I think are the relevant parts of the code of these two classes. First, TreePointer (original source here): public abstract class TreePointer<T extends TreeNode> implements Iterable<TokenResolver<T>> { //... /** * What this tree can see as a missing node (may be {@code null}) */ private final T missing; /** * The list of token resolvers */ protected final List<TokenResolver<T>> tokenResolvers; /** * Main protected constructor * * <p>This constructor makes an immutable copy of the list it receives as * an argument.</p> * * @param missing the representation of a missing node (may be null) * @param tokenResolvers the list of reference token resolvers */ protected TreePointer(final T missing, final List<TokenResolver<T>> tokenResolvers) { this.missing = missing; this.tokenResolvers = ImmutableList.copyOf(tokenResolvers); } /** * Alternate constructor * * <p>This is the same as calling {@link #TreePointer(TreeNode, List)} with * {@code null} as the missing node.</p> * * @param tokenResolvers the list of token resolvers */ protected TreePointer(final List<TokenResolver<T>> tokenResolvers) { this(null, tokenResolvers); } //... /** * Tell whether this pointer is empty * * @return true if the reference token list is empty */ public final boolean isEmpty() { return tokenResolvers.isEmpty(); } @Override public final Iterator<TokenResolver<T>> iterator() { return tokenResolvers.iterator(); } // .equals(), .hashCode(), .toString() follow } Then, JsonPointer, which contains this .parent() method which I'd like to factorize here (original source here: public final class JsonPointer extends TreePointer<JsonNode> { /** * The empty JSON Pointer */ private static final JsonPointer EMPTY = new JsonPointer(ImmutableList.<TokenResolver<JsonNode>>of()); /** * Return an empty JSON Pointer * * @return an empty, statically allocated JSON Pointer */ public static JsonPointer empty() { return EMPTY; } //... /** * Return the immediate parent of this JSON Pointer * * <p>The parent of the empty pointer is itself.</p> * * @return a new JSON Pointer representing the parent of the current one */ public JsonPointer parent() { final int size = tokenResolvers.size(); return size <= 1 ? EMPTY : new JsonPointer(tokenResolvers.subList(0, size - 1)); } // ... } As mentioned in the subject, the problem I have here is with JsonPointer's .parent() method. In fact, the logic behind this method applies to TreeNode all the same, and therefore to its future implementations. Except that I have to use a constructor, and of course such a constructor is implementation dependent :/ Is there a way to make that .parent() method available to each and every implementation of TreeNode or is it just a pipe dream?

  Read the article

• Load HTML NSString into a UIWebView

  - by ehenrik

  Im doing a project where I connect to a webpage using the NSURLConnection to be able to monitor the status codes that are returned (200 OK / 404 ERROR). I would like to send the user to the top url www.domain.com if I recieve 404 as status code and if i recieve as 200 status code I would like to load the page in to a webview. I have seen several implementations of this problem by creating a new request but I feel that it is unnecessary since you already received the html in the first request so i would just like to load that HTML in to the webView. So i try to use the [webView loadHTMLFromString: baseURL:] but it doesn't always work, I have noticed that when i print the NSString with html in the connectionDidFinnishLoading it sometimes is null and when I monitor these cases by printing the html in didReceiveData a random number of the last packets is NULL (differs between 2-10). It is always the same webpages that doesn't get loaded. If I load them to my webView using [webView loadRequest:myRequest] it always works. My implementation looks like this perhaps someone of you can see what Im doing wrong. I create my first request with a button click. -(IBAction)buttonClick:(id)sender { NSURL *url = [NSURL URLWithString:@"http://www.domain.com/page2/apa.html"]; NSURLRequest *theRequest = [NSURLRequest requestWithURL:url] NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self]; if( theConnection ) { webData = [[NSMutableData data] retain]; } else { } } Then I monitor the response code in the didReceiveResponse method by casting the request to a NSHTTPURLResponse to be able to access the status codes and then setting a Bool depending on the status code. -(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { NSHTTPURLResponse *ne = (NSHTTPURLResponse *)response; if ([ne statusCode] == 200){ ok = TRUE; } [webData setLength: 0]; } I then check the bools value in connectionDidFinnishLoading. If I log the html NSString I get the source of the webpage so i know that it isn't an empty string. -(void)connectionDidFinishLoading:(NSURLConnection *)connection { NSString *html = [[NSString alloc] initWithBytes: [webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding]; NSURL *url = [NSURL URLWithString:@"http://www.domain.com/"]; if (ok){ [webView loadHTMLString:html baseURL:url]; ok = FALSE; } else{ //Create a new request to www.domain.com } } webData is an instance variable and I load it in didReceiveData like this. -(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { [webData appendData:data]; }

  Read the article

• Parallelism in .NET – Part 5, Partitioning of Work

  - by Reed

  When parallelizing any routine, we start by decomposing the problem.  Once the problem is understood, we need to break our work into separate tasks, so each task can be run on a different processing element.  This process is called partitioning. Partitioning our tasks is a challenging feat.  There are opposing forces at work here: too many partitions adds overhead, too few partitions leaves processors idle.  Trying to work the perfect balance between the two extremes is the goal for which we should aim.  Luckily, the Task Parallel Library automatically handles much of this process.  However, there are situations where the default partitioning may not be appropriate, and knowledge of our routines may allow us to guide the framework to making better decisions. First off, I’d like to say that this is a more advanced topic.  It is perfectly acceptable to use the parallel constructs in the framework without considering the partitioning taking place.  The default behavior in the Task Parallel Library is very well-behaved, even for unusual work loads, and should rarely be adjusted.  I have found few situations where the default partitioning behavior in the TPL is not as good or better than my own hand-written partitioning routines, and recommend using the defaults unless there is a strong, measured, and profiled reason to avoid using them.  However, understanding partitioning, and how the TPL partitions your data, helps in understanding the proper usage of the TPL. I indirectly mentioned partitioning while discussing aggregation.  Typically, our systems will have a limited number of Processing Elements (PE), which is the terminology used for hardware capable of processing a stream of instructions.  For example, in a standard Intel i7 system, there are four processor cores, each of which has two potential hardware threads due to Hyperthreading.  This gives us a total of 8 PEs – theoretically, we can have up to eight operations occurring concurrently within our system. In order to fully exploit this power, we need to partition our work into Tasks.  A task is a simple set of instructions that can be run on a PE.  Ideally, we want to have at least one task per PE in the system, since fewer tasks means that some of our processing power will be sitting idle.  A naive implementation would be to just take our data, and partition it with one element in our collection being treated as one task.  When we loop through our collection in parallel, using this approach, we’d just process one item at a time, then reuse that thread to process the next, etc.  There’s a flaw in this approach, however.  It will tend to be slower than necessary, often slower than processing the data serially. The problem is that there is overhead associated with each task.  When we take a simple foreach loop body and implement it using the TPL, we add overhead.  First, we change the body from a simple statement to a delegate, which must be invoked.  In order to invoke the delegate on a separate thread, the delegate gets added to the ThreadPool’s current work queue, and the ThreadPool must pull this off the queue, assign it to a free thread, then execute it.  If our collection had one million elements, the overhead of trying to spawn one million tasks would destroy our performance. The answer, here, is to partition our collection into groups, and have each group of elements treated as a single task.  By adding a partitioning step, we can break our total work into small enough tasks to keep our processors busy, but large enough tasks to avoid overburdening the ThreadPool.  There are two clear, opposing goals here: Always try to keep each processor working, but also try to keep the individual partitions as large as possible. When using Parallel.For, the partitioning is always handled automatically.  At first, partitioning here seems simple.  A naive implementation would merely split the total element count up by the number of PEs in the system, and assign a chunk of data to each processor.  Many hand-written partitioning schemes work in this exactly manner.  This perfectly balanced, static partitioning scheme works very well if the amount of work is constant for each element.  However, this is rarely the case.  Often, the length of time required to process an element grows as we progress through the collection, especially if we’re doing numerical computations.  In this case, the first PEs will finish early, and sit idle waiting on the last chunks to finish.  Sometimes, work can decrease as we progress, since previous computations may be used to speed up later computations.  In this situation, the first chunks will be working far longer than the last chunks.  In order to balance the workload, many implementations create many small chunks, and reuse threads.  This adds overhead, but does provide better load balancing, which in turn improves performance. The Task Parallel Library handles this more elaborately.  Chunks are determined at runtime, and start small.  They grow slowly over time, getting larger and larger.  This tends to lead to a near optimum load balancing, even in odd cases such as increasing or decreasing workloads.  Parallel.ForEach is a bit more complicated, however. When working with a generic IEnumerable<T>, the number of items required for processing is not known in advance, and must be discovered at runtime.  In addition, since we don’t have direct access to each element, the scheduler must enumerate the collection to process it.  Since IEnumerable<T> is not thread safe, it must lock on elements as it enumerates, create temporary collections for each chunk to process, and schedule this out.  By default, it uses a partitioning method similar to the one described above.  We can see this directly by looking at the Visual Partitioning sample shipped by the Task Parallel Library team, and available as part of the Samples for Parallel Programming.  When we run the sample, with four cores and the default, Load Balancing partitioning scheme, we see this: The colored bands represent each processing core.  You can see that, when we started (at the top), we begin with very small bands of color.  As the routine progresses through the Parallel.ForEach, the chunks get larger and larger (seen by larger and larger stripes). Most of the time, this is fantastic behavior, and most likely will out perform any custom written partitioning.  However, if your routine is not scaling well, it may be due to a failure in the default partitioning to handle your specific case.  With prior knowledge about your work, it may be possible to partition data more meaningfully than the default Partitioner. There is the option to use an overload of Parallel.ForEach which takes a Partitioner<T> instance.  The Partitioner<T> class is an abstract class which allows for both static and dynamic partitioning.  By overriding Partitioner<T>.SupportsDynamicPartitions, you can specify whether a dynamic approach is available.  If not, your custom Partitioner<T> subclass would override GetPartitions(int), which returns a list of IEnumerator<T> instances.  These are then used by the Parallel class to split work up amongst processors.  When dynamic partitioning is available, GetDynamicPartitions() is used, which returns an IEnumerable<T> for each partition.  If you do decide to implement your own Partitioner<T>, keep in mind the goals and tradeoffs of different partitioning strategies, and design appropriately. The Samples for Parallel Programming project includes a ChunkPartitioner class in the ParallelExtensionsExtras project.  This provides example code for implementing your own, custom allocation strategies, including a static allocator of a given chunk size.  Although implementing your own Partitioner<T> is possible, as I mentioned above, this is rarely required or useful in practice.  The default behavior of the TPL is very good, often better than any hand written partitioning strategy.

  Read the article

• Database users in the Oracle Utilities Application Framework

  - by Anthony Shorten

  I mentioned the product database users fleetingly in the last blog post and they deserve a better mention. This applies to all versions of the Oracle Utilities Application Framework. The Oracle Utilities Application Framework uses up to three users initially as part of the base operations of the product. The type of database supported (the framework supports Oracle, IBM DB2 and Microsoft SQL Server) dictates the number of users used and their permissions. For publishing brevity I will outline what is available for the Oracle database and, in summary, mention where it differs for the other database supported. For Oracle database customers we ship three distinct database users: Administration User (SPLADM or CISADM by default) - This is the database user that actually owns the schema. This user is not used by the product to do any DML (Data Manipulation Language) SQL other than that is necessary for maintenance of the database. This database user performs all the DCL (Data Control Language) and DDL (Data Definition Language) against the database. It is typically reserved for Database Administration use only. Product Read Write User (SPLUSER or CISUSER by default) - This is the database user used by the product itself to execute DML (Data Manipulation Language) statements against the schema owned by the Administration user. This user has the appropriate read and write permission to objects within the schema owned by the Administration user. For databases such as DB2 and SQL Server we may not create this user but use other DCL (Data Control Language) statements and facilities to simulate this user. Product Read User (SPLREAD or CISREAD by default) - This is the database that has read only permission to the schema owned by the Administration user. It is used for reporting or any part of the product or interface that requires read permissions to the database (for example, products that have ConfigLab and Archiving use this user for remote access). For databases such as DB2 and SQL Server we may not create this user but use other DCL (Data Control Language) statements and facilities to simulate this user. You may notice the words by default in the list above. The values supplied with the installer are the default and can be changed to what the site standard or implementation wants to use (as long as they conform to the standards supported by the underlying database). You can even create multiples of each within the same database and pointing to same schema. To manage the permissions for the users, there is a utility provided with the installation (oragensec (Oracle), db2gensec (DB2) or msqlgensec (SQL Server)) that generates the security definitions for the above users. That can be executed a number of times for each schema to give users appropriate permissions. For example, it is possible to define more than one read/write User to access the database. This is a common technique used by implementations to have a different user per access mode (to separate online and batch). In fact you can also allocate additional security (such as resource profiles in Oracle) to limit the impact of specific users at the database. To facilitate users and permissions, in Oracle for example, we create a CISREAD role (read only role) and a CISUSER role (read write role) that can be allocated to the appropriate database user. When the security permissions utility, oragensec in this case, is executed it uses the role to determine the permissions. To give you a case study, my underpowered laptop has multiple installations on it of multiple products but I have one database. I create a different schema for each product and each version (with my own naming convention to help me manage the databases). I create individual users on each schema and run oragensec to maintain the permissions for each appropriately. It works fine as long I have setup the userids appropriately. This means: Creating the users with the appropriate roles. I use the common CISUSER and CISREAD role across versions and across Oracle Utilities Application Framework products. Just remember to associate the CISUSER role with the database user you want to use for read/write operations and the CISREAD role with the user you wish to use for the read only operations. The role is treated as a tag to indicate the oragensec utility which appropriate permissions to assign to the user. The utilities for the other database types essentially do the same, obviously using the technology available within those databases. Run oragensec against the read write user and read only user against the appropriate administration user (I will abbreviate the user to ADM user). This ensures the right permissions are allocated to the right users for the right products. To help me there, I use the same prefix on the user name for the same product. For example, my Oracle Utilities Application Framework V4 environment has the administration user set to FW4ADM and the associated FW4USER and FW4READ as the users for the product to use. For my MWM environment I used MWMADM for the administration user and MWMUSER and MWMREAD for my associated users. You get the picture. When I run oragensec (once for each ADM user), I know what other users to associate with it. Remember to rerun oragensec against the users if I run upgrades, service packs or database based single fixes. This assures that the users are in synchronization with the ADM user. As a side note, for those who do not understand the difference between DML, DCL and DDL: DDL (Data Definition Language) - These are SQL statements that define the database schema and the structures within. SQL Statements such as CREATE and DROP are examples of DDL SQL statements. DCL (Data Control Language) - These are the SQL statements that define the database level permissions to DDL maintained objects within the database. SQL Statements such as GRANT and REVOKE are examples of DCL SQL statements. DML (Database Manipulation Language) - These are SQL statements that alter the data within the tables. SQL Statements such as SELECT, INSERT, UPDATE and DELETE are examples of DML SQL statements. Hope this has clarified the database user support. Remember in Oracle Utilities Application Framework V4 we enhanced this by also supporting CLIENT_IDENTIFIER to allow the database to still use the administration user for the main processing but make the database session more traceable.

  Read the article

• Thursday Community Keynote: "By the Community, For the Community"

  - by Janice J. Heiss

  Sharat Chander, JavaOne Community Chairperson, began Thursday's Community Keynote. As part of the morning’s theme of "By the Community, For the Community," Chander noted that 60% of the material at the 2012 JavaOne conference was presented by Java Community members. "So next year, when the call for papers starts, put-in your submissions," he urged.From there, Gary Frost, Principal Member of Technical Staff, AMD, expanded upon Sunday's Strategy Keynote exploration of Project Sumatra, an OpenJDK project targeted at bringing Java to heterogeneous computing platforms (which combine the CPU and the parallel processor of the GPU into a single piece of silicon). Sumatra entails enhancing the JVM to make maximum use of these advanced platforms. Within this development space, AMD created the Aparapi API, which converts Java bytecode into OpenCL for execution on such GPU devices. The Aparapi API was open sourced in September 2011.Whether it was zooming-in on a Mandelbrot set, "the game of life," or a swarm of 10,000 Dukes in a space-bound gravitational dance, Frost's demos, using an Aparapi/OpenCL implementation, produced stunningly faster display results. He indicated that the Java 9 timeframe is where they see Project Sumatra coming to ultimate fruition, employing the Lamdas of Java 8.Returning to the theme of the keynote, Donald Smith, Director, Java Product Management, Oracle, explored a mind map graphic demonstrating the importance of Community in terms of fostering innovation. "It's the sharing and mixing of culture, the diversity, and the rapid prototyping," he said. Within this topic, Smith, brought up a panel of representatives from Cloudera, Eclipse, Eucalyptus, Perrone Robotics, and Twitter--ideal manifestations of community and innovation in the world of Java.Marten Mickos, CEO, Eucalyptus Systems, explored his company's open source cloud software platform, written in Java, and used by gaming companies, technology companies, media companies, and more. Chris Aniszczyk, Operations Engineering,Twitter, noted the importance of the JVM in terms of their multiple-language development environment. Mike Olson, CEO, Cloudera, described his company's Apache Hadoop-based software, support, and training. Mike Milinkovich, Executive Director, Eclipse Foundation, noted that they have about 270 tools projects at Eclipse, with 267 of them written in Java. Milinkovich added that Eclipse will even be going into space in 2013, as part of the control software on various experiments aboard the International Space Station. Lastly, Paul Perrone, CEO, Perrone Robotics, detailed his company's robotics and automation software platform built 100% on Java, including Java SE and Java ME--"on rat, to cat, to elephant-sized systems." Milinkovic noted that communities are by nature so good at innovation because of their very openness--"The more open you make your innovation process, the more ideas are challenged, and the more developers are focused on justifying their choices all the way through the process."From there, Georges Saab, VP Development Java SE OpenJDK, continued the topic of innovation and helping the Java Community to "Make the Future Java." Martijn Verburg, representing the London Java Community (winner of a Duke's Choice Award 2012 for their activity in OpenJDK and JCP), soon joined Saab onstage. Verburg detailed the LJC's "Adopt a JSR" program--"to get day-to-day developers more involved in the innovation that's happening around them."  From its London launching pad, the innovative program has spread to Brazil, Morocco, Latvia, India, and more.Other active participants in the program joined Verburg onstage--Ben Evans, London Java Community; James Gough, Stackthread; Bruno Souza, SOUJava; Richard Warburton, jClarity; and Cecelia Borg, Oracle--OpenJDK Onboarding. Together, the group explored the goals and tasks inherent in the Adopt a JSR program--from organizing hack days (testing prototype implementations), to managing mailing lists and forums, to triaging issues, to evangelism—all with the goal of fostering greater community/developer involvement, but equally importantly, building better open standards. “Come join us, and make your ecosystem better!" urged Verburg.Paul Perrone returned to profile the latest in his company's robotics work around Java--including the AARDBOTS family of smaller robotic vehicles, running the Perrone MAX platform on top of the Java JVM. Perrone took his "Rumbles" four-wheeled robot out for a spin onstage--a roaming, ARM-based security-bot vehicle, complete with IR, ultrasonic, and "cliff" sensors (the latter, for the raised stage at JavaOne). As an ultimate window into the future of robotics, Perrone displayed a "head-set" controller--a sensor directed at the forehead to monitor brainwaves, for the someday-implementation of brain-to-robot control.Then, just when it seemed this might be the end of the day's futuristic offerings, a mystery voice from offstage pronounced "I've got some toys"--proving to be guest-visitor James Gosling, there to explore his cutting-edge work with Liquid Robotics. While most think of robots as something with wheels or arms or lasers, Gosling explained, the Liquid Robotics vehicle is an entirely new and innovative ocean-going 'bot. Looking like a floating surfboard, with an attached set of underwater wings, the autonomous devices roam the oceans using only the energy of ocean waves to propel them, and a single actuated rudder to steer. "We have to accomplish all guidance just by wiggling the rudder," Gosling said. The devices offer applications from self-installing weather buoy, to pollution monitoring station, to marine mammal monitoring device, to climate change data gathering, to even ocean life genomic sampling. The early versions of the vehicle used C code on very tiny industrial micro controllers, where they had to "count the bytes one at a time."  But the latest generation vehicles, which just hit the water a week or so ago, employ an ARM processor running Linux and the ARM version of JDK 7. Gosling explained that vehicle communication from remote locations is achieved via the Iridium satellite network. But because of the costs of this communication path, the data must be sent in very small bursts--using SBD short burst data. "It costs $1/kb, so that rules everything in the software design,” said Gosling. “If you were trying to stream a Netflix video over this, it would cost a million dollars a movie. …We don't have a 'big data' problem," he quipped. There are currently about 150 Liquid Robotics vehicles out traversing the oceans. Gosling demonstrated real time satellite tracking of several vehicles currently at sea, noting that Java is actually particularly good at AI applications--due to the language having garbage collection, which facilitates complex data structures. To close-out his time onstage, Gosling of course participated in the ceremonial Java tee-shirt toss out to the audience…In parting, Chander passed the JavaOne Community Chairperson baton to Stephen Chin, Java Technology Evangelist, Oracle. Onstage in full motorcycle gear, Chin noted that he'll soon be touring Europe by motorcycle, meeting Java Community Members and streaming live via UStream--the ultimate manifestation of community and technology!  He also reminded attendees of the upcoming JavaOne Latin America 2012, São Paulo, Brazil (December 4-6, 2012), and stated that the CFP (call for papers) at the conference has been extended for one more week. "Remember, December is summer in Brazil!" Chin said.

  Read the article

• Interesting articles and blogs on SPARC T4

  - by mv

  Interesting articles and blogs on SPARC T4 processor   I have consolidated all the interesting information I could get on SPARC T4 processor and its hardware cryptographic capabilities.  Hope its useful. 1. Advantages of SPARC T4 processor  Most important points in this T4 announcement are : "The SPARC T4 processor was designed from the ground up for high speed security and has a cryptographic stream processing unit (SPU) integrated directly into each processor core. These accelerators support 16 industry standard security ciphers and enable high speed encryption at rates 3 to 5 times that of competing processors. By integrating encryption capabilities directly inside the instruction pipeline, the SPARC T4 processor eliminates the performance and cost barriers typically associated with secure computing and makes it possible to deliver high security levels without impacting the user experience." Data Sheet has more details on these  : "New on-chip Encryption Instruction Accelerators with direct non-privileged support for 16 industry-standard cryptographic algorithms plus random number generation in each of the eight cores: AES, Camellia, CRC32c, DES, 3DES, DH, DSA, ECC, Kasumi, MD5, RSA, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512" I ran "isainfo -v" command on Solaris 11 Sparc T4-1 system. It shows the new instructions as expected  : $ isainfo -v 64-bit sparcv9 applications crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5 camellia kasumi des aes ima hpc vis3 fmaf asi_blk_init vis2 vis popc 32-bit sparc applications crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5 camellia kasumi des aes ima hpc vis3 fmaf asi_blk_init vis2 vis popc v8plus div32 mul32  2.  Dan Anderson's Blog have some interesting points about how these can be used : "New T4 crypto instructions include: aes_kexpand0, aes_kexpand1, aes_kexpand2,         aes_eround01, aes_eround23, aes_eround01_l, aes_eround_23_l, aes_dround01, aes_dround23, aes_dround01_l, aes_dround_23_l.       Having SPARC T4 hardware crypto instructions is all well and good, but how do we access it ?      The software is available with Solaris 11 and is used automatically if you are running Solaris a SPARC T4.  It is used internally in the kernel through kernel crypto modules.  It is available in user space through the PKCS#11 library." 3.   Dans' Blog on Where's the Crypto Libraries? Although this was written in 2009 but still is very useful  "Here's a brief tour of the major crypto libraries shown in the digraph:   The libpkcs11 library contains the PKCS#11 API (C_\*() functions, such as C_Initialize()). That in turn calls library pkcs11_softtoken or pkcs11_kernel, for userland or kernel crypto providers. The latter is used mostly for hardware-assisted cryptography (such as n2cp for Niagara2 SPARC processors), as that is performed more efficiently in kernel space with the "kCF" module (Kernel Crypto Framework). Additionally, for Solaris 10, strong crypto algorithms were split off in separate libraries, pkcs11_softtoken_extra libcryptoutil contains low-level utility functions to help implement cryptography. libsoftcrypto (OpenSolaris and Solaris Nevada only) implements several symmetric-key crypto algorithms in software, such as AES, RC4, and DES3, and the bignum library (used for RSA). libmd implements MD5, SHA, and SHA2 message digest algorithms" 4. Difference in T3 and T4 Diagram in this blog is good and self explanatory. Jeff's blog also highlights the differences  "The T4 servers have improved crypto acceleration, described at https://blogs.oracle.com/DanX/entry/sparc_t4_openssl_engine. It is "just built in" so administrators no longer have to assign crypto accelerator units to domains - it "just happens". Every physical or virtual CPU on a SPARC-T4 has full access to hardware based crypto acceleration at all times. .... For completeness sake, it's worth noting that the T4 adds more crypto algorithms, and accelerates Camelia, CRC32c, and more SHA-x." 5. About performance counters In this blog, performance counters are explained : "Note that unlike T3 and before, T4 crypto doesn't require kernel modules like ncp or n2cp, there is no visibility of crypto hardware with kstats or cryptoadm. T4 does provide hardware counters for crypto operations.  You can see these using cpustat: cpustat -c pic0=Instr_FGU_crypto 5 You can check the general crypto support of the hardware and OS with the command "isainfo -v". Since T4 crypto's implementation now allows direct userland access, there are no "crypto units" visible to cryptoadm.  " For more details refer Martin's blog as well. 6. How to turn off  SPARC T4 or Intel AES-NI crypto acceleration  I found this interesting blog from Darren about how to turn off  SPARC T4 or Intel AES-NI crypto acceleration. "One of the new Solaris 11 features of the linker/loader is the ability to have a single ELF object that has multiple different implementations of the same functions that are selected at runtime based on the capabilities of the machine.   The alternate to this is having the application coded to call getisax(2) system call and make the choice itself.  We use this functionality of the linker/loader when we build the userland libraries for the Solaris Cryptographic Framework (specifically libmd.so and libsoftcrypto.so) The Solaris linker/loader allows control of a lot of its functionality via environment variables, we can use that to control the version of the cryptographic functions we run.  To do this we simply export the LD_HWCAP environment variable with values that tell ld.so.1 to not select the HWCAP section matching certain features even if isainfo says they are present.  This will work for consumers of the Solaris Cryptographic Framework that use the Solaris PKCS#11 libraries or use libmd.so interfaces directly.  For SPARC T4 : export LD_HWCAP="-aes -des -md5 -sha256 -sha512 -mont -mpul" .. For Intel systems with AES-NI support: export LD_HWCAP="-aes"" Note that LD_HWCAP is explained in  http://docs.oracle.com/cd/E23823_01/html/816-5165/ld.so.1-1.html "LD_HWCAP, LD_HWCAP_32, and LD_HWCAP_64 -  Identifies an alternative hardware capabilities value... A “-” prefix results in the capabilities that follow being removed from the alternative capabilities." 7. Whitepaper on SPARC T4 Servers—Optimized for End-to-End Data Center Computing This Whitepaper on SPARC T4 Servers—Optimized for End-to-End Data Center Computing explains more details.  It has DTrace scripts which may come in handy : "To ensure the hardware-assisted cryptographic acceleration is configured to use and working with the security scenarios, it is recommended to use the following Solaris DTrace script. #!/usr/sbin/dtrace -s pid$1:libsoftcrypto:yf*:entry, pid$target:libsoftcrypto:rsa*:entry, pid$1:libmd:yf*:entry { @[probefunc] = count(); } tick-1sec { printa(@ops); trunc(@ops); }" Note that I have slightly modified the D Script to have RSA "libsoftcrypto:rsa*:entry" as well as per recommendations from Chi-Chang Lin. 8. References http://www.oracle.com/us/corporate/features/sparc-t4-announcement-494846.html http://www.oracle.com/us/products/servers-storage/servers/sparc-enterprise/t-series/sparc-t4-1-ds-487858.pdf https://blogs.oracle.com/DanX/entry/sparc_t4_openssl_engine https://blogs.oracle.com/DanX/entry/where_s_the_crypto_libraries https://blogs.oracle.com/darren/entry/howto_turn_off_sparc_t4 http://docs.oracle.com/cd/E23823_01/html/816-5165/ld.so.1-1.html   https://blogs.oracle.com/hardware/entry/unleash_the_power_of_cryptography https://blogs.oracle.com/cmt/entry/t4_crypto_cheat_sheet https://blogs.oracle.com/martinm/entry/t4_performance_counters_explained  https://blogs.oracle.com/jsavit/entry/no_mau_required_on_a http://www.oracle.com/us/products/servers-storage/servers/sparc-enterprise/t-series/sparc-t4-business-wp-524472.pdf

  Read the article

• Is Berkeley DB a NoSQL solution?

  - by Gregory Burd

  Berkeley DB is a library. To use it to store data you must link the library into your application. You can use most programming languages to access the API, the calls across these APIs generally mimic the Berkeley DB C-API which makes perfect sense because Berkeley DB is written in C. The inspiration for Berkeley DB was the DBM library, a part of the earliest versions of UNIX written by AT&T's Ken Thompson in 1979. DBM was a simple key/value hashtable-based storage library. In the early 1990s as BSD UNIX was transitioning from version 4.3 to 4.4 and retrofitting commercial code owned by AT&T with unencumbered code, it was the future founders of Sleepycat Software who wrote libdb (aka Berkeley DB) as the replacement for DBM. The problem it addressed was fast, reliable local key/value storage. At that time databases almost always lived on a single node, even the most sophisticated databases only had simple fail-over two node solutions. If you had a lot of data to store you would choose between the few commercial RDBMS solutions or to write your own custom solution. Berkeley DB took the headache out of the custom approach. These basic market forces inspired other DBM implementations. There was the "New DBM" (ndbm) and the "GNU DBM" (GDBM) and a few others, but the theme was the same. Even today TokyoCabinet calls itself "a modern implementation of DBM" mimicking, and improving on, something first created over thirty years ago. In the mid-1990s, DBM was the name for what you needed if you were looking for fast, reliable local storage. Fast forward to today. What's changed? Systems are connected over fast, very reliable networks. Disks are cheep, fast, and capable of storing huge amounts of data. CPUs continued to follow Moore's Law, processing power that filled a room in 1990 now fits in your pocket. PCs, servers, and other computers proliferated both in business and the personal markets. In addition to the new hardware entire markets, social systems, and new modes of interpersonal communication moved onto the web and started evolving rapidly. These changes cause a massive explosion of data and a need to analyze and understand that data. Taken together this resulted in an entirely different landscape for database storage, new solutions were needed. A number of novel solutions stepped up and eventually a category called NoSQL emerged. The new market forces inspired the CAP theorem and the heated debate of BASE vs. ACID. But in essence this was simply the market looking at what to trade off to meet these new demands. These new database systems shared many qualities in common. There were designed to address massive amounts of data, millions of requests per second, and scale out across multiple systems. The first large-scale and successful solution was Dynamo, Amazon's distributed key/value database. Dynamo essentially took the next logical step and added a twist. Dynamo was to be the database of record, it would be distributed, data would be partitioned across many nodes, and it would tolerate failure by avoiding single points of failure. Amazon did this because they recognized that the majority of the dynamic content they provided to customers visiting their web store front didn't require the services of an RDBMS. The queries were simple, key/value look-ups or simple range queries with only a few queries that required more complex joins. They set about to use relational technology only in places where it was the best solution for the task, places like accounting and order fulfillment, but not in the myriad of other situations. The success of Dynamo, and it's design, inspired the next generation of Non-SQL, distributed database solutions including Cassandra, Riak and Voldemort. The problem their designers set out to solve was, "reliability at massive scale" so the first focal point was distributed database algorithms. Underneath Dynamo there is a local transactional database; either Berkeley DB, Berkeley DB Java Edition, MySQL or an in-memory key/value data structure. Dynamo was an evolution of local key/value storage onto networks. Cassandra, Riak, and Voldemort all faced similar design decisions and one, Voldemort, choose Berkeley DB Java Edition for it's node-local storage. Riak at first was entirely in-memory, but has recently added write-once, append-only log-based on-disk storage similar type of storage as Berkeley DB except that it is based on a hash table which must reside entirely in-memory rather than a btree which can live in-memory or on disk. Berkeley DB evolved too, we added high availability (HA) and a replication manager that makes it easy to setup replica groups. Berkeley DB's replication doesn't partitioned the data, every node keeps an entire copy of the database. For consistency, there is a single node where writes are committed first - a master - then those changes are delivered to the replica nodes as log records. Applications can choose to wait until all nodes are consistent, or fire and forget allowing Berkeley DB to eventually become consistent. Berkeley DB's HA scales-out quite well for read-intensive applications and also effectively eliminates the central point of failure by allowing replica nodes to be elected (using a PAXOS algorithm) to mastership if the master should fail. This implementation covers a wide variety of use cases. MemcacheDB is a server that implements the Memcache network protocol but uses Berkeley DB for storage and HA to replicate the cache state across all the nodes in the cache group. Google Accounts, the user authentication layer for all Google properties, was until recently running Berkeley DB HA. That scaled to a globally distributed system. That said, most NoSQL solutions try to partition (shard) data across nodes in the replication group and some allow writes as well as reads at any node, Berkeley DB HA does not. So, is Berkeley DB a "NoSQL" solution? Not really, but it certainly is a component of many of the existing NoSQL solutions out there. Forgetting all the noise about how NoSQL solutions are complex distributed databases when you boil them down to a single node you still have to store the data to some form of stable local storage. DBMs solved that problem a long time ago. NoSQL has more to do with the layers on top of the DBM; the distributed, sometimes-consistent, partitioned, scale-out storage that manage key/value or document sets and generally have some form of simple HTTP/REST-style network API. Does Berkeley DB do that? Not really. Is Berkeley DB a "NoSQL" solution today? Nope, but it's the most robust solution on which to build such a system. Re-inventing the node-local data storage isn't easy. A lot of people are starting to come to appreciate the sophisticated features found in Berkeley DB, even mimic them in some cases. Could Berkeley DB grow into a NoSQL solution? Absolutely. Our key/value API could be extended over the net using any of a number of existing network protocols such as memcache or HTTP/REST. We could adapt our node-local data partitioning out over replicated nodes. We even have a nice query language and cost-based query optimizer in our BDB XML product that we could reuse were we to build out a document-based NoSQL-style product. XML and JSON are not so different that we couldn't adapt one to work with the other interchangeably. Without too much effort we could add what's missing, we could jump into this No SQL market withing a single product development cycle. Why isn't Berkeley DB already a NoSQL solution? Why aren't we working on it? Why indeed...

  Read the article

• CodePlex Daily Summary for Monday, May 03, 2010

  CodePlex Daily Summary for Monday, May 03, 2010New Projects.radiko: エアログラス採用のシンプルなradiko(http://radiko.jp/)クライアントです。タスクトレイのアイコンからラジオ局の切り替えができます。7Scale: EmptyB2C MVC Plattform: The B2C MVC Plattform aims to be pluggable site framework to help small busisness accomplish basic tasks between business and customers.ElValWeb: The goal of the project to create full featured implementation of ModelValidatorProvider for Enterprise Library Application Validation Block, wich ...esatis yazilimi: asp.net yazılımı ile satış magazasi websitesi kur.IEnumerable.It sample code: IEnumerable.It sample codejQuery MicroAjax for ASP.NET: MicroAjax is a set of jQuery plugins and .NET components designed to provide simple, powerful and efficient Ajax centric web application design pat...Karbon VOS: Karbon VOS is an advanced Virtual Operating System Template for Visual Basic Express. It's developed in Visual Basic. Karbon VOS hopes to one day b...LINQ Mapper: LINQ Mapper translates simple LINQ queries between different sources. It allows you to write queries against your domain model, but have them run ...Meccano Silverlight Framework: Meccano is a new generation of frameworks for creation of LOB Silverlight applications based on MEF, RX, WCF, ADO.NET Data Services etc. It is inte...Multiuse Model View (MMV) Library: This project is an open source library for the Multiuse Model View (MMV) pattern for building robust WPF and ASP.Net applications. Visit my blog ht...Process Affinity Control: Process Affinity Control allows to set the affinity masks of processes based on rules.SilverSpatial: This project helps bridge the gap between Silverlight and Geo-Spatial data type (such as SQL Spatial). It implements the Well-Known-Binary (WKB) fo...StageAssets: Application for storing data about "things" and people in theatre. For example equipment, actors and so on.Stratosphere: Mono compatible library with set of primitives to work with scalable table, queue and block containers with corresponding implementations for Amazo...TRX Web-Viewer: A simple web-based application to upload and view VSTS 2008 and VSTS 2010 test result files with some basic lookup and feature-wise management of r...WDT2: WDT 2 is the school project to begin learning .NET enviroment, The main focus is on learning the use of almost all the componenets.WPF Behavior Library: WPF Behavior Library is a set of additional actions for WPF that allow you to add extra behaviors to a control quickly and easily. Currently the on...YouTubeEmbeddedVideo WebControl for ASP.NET: A Control to embed YouTube videos in ASP.NET pages. Works in C# and VB.NETNew Releases.radiko: beta: 東京局のみ対応 あとは手抜きActiveWorlds Managed .NET SDK: AwManaged Technology Preview - WIN32 (Alpha): This WIN32 release contains the Server Console Application. The Setup executable should be run as administrator on O.S. using UAC (Vista/Win7)AJAX Control Framework: v1.0.1.0: v1.0.1.0 - Contains a Bing Maps sample project, a number of bug fixes and a few performance improvements. - AJAX enable ANY custom control that der...App_Code (and Usercontrol) Editor (ACE): v1.0.0 alpha: The first alpha release of the AppCode Editor for Umbraco 4.0.3 is now available to download! Tested to work with usercontrols - pre-compilation wi...ElValWeb: ElValWeb 0.0.1.0: Version 0.0.1.0 contains client validation support forAndCompositeValidator ContainsCharactersValidator DomainValidator NotNullValidator Or...esatis yazilimi: magaza: magazanın yazılımları ve veri tabanının yazılımlarıGrunty OS: Grunty OS USB: Download Grunty OS for USBGrunty OS: Grunty OS.ISO: Grunty OS ISOKarbon VOS: Milestone 1 (Kaptua): Milestone 1...Live Meeting API Wrapper: LiveMeetingAPIWrapperV1.2: Added get meeting and update meeting.Multiuse Model View (MMV) Library: v0.3: first alpha release. Medium amount of functionality and some use cases tested.MVC Foolproof Validation: Beta 0.9.3774: Adds resource provided error messages, regular expression operators and a new RegularExpressionIf attribute.Process Affinity Control: Version 1.0.0: This is the first release. Planned features for the next release: No administrative privileges needed to run the manager Select the active scena...SharePoint 2010 Service Manager: SharePoint 2010 Service Manager 1.1: Added support to run under UAC with automatic security elevationSharePoint Event Handler Manager: Event Handler Manager 2.0: Please download the application here: http://www.ackermantech.com/registerevents.aspxSkyDrive Synchronizer: SkyDrive Sync Beta 0.1: Beta release includes: Upload and download Synchronize updated files Delete files on web/locally if not in source Split larger files into sma...Stratosphere: Stratosphere 1.0.0.0: Initial beta releaseSuggested Resources for .NET Developers: 0.8.0.0 VS2010 - focus on displaying content: This is the first release of Suggested Resources that can be downloaded from the internet. While there is still a lot of work to be done this rele...TRX Web-Viewer: TRX Web-Viewer V1.0: First working versionVCC: Latest build, v2.1.30502.0: Automatic drop of latest buildWatchersNET.TagCloud: WatchersNET.TagCloud 01.04.00: !Whats New New Tag Mode: Search Referrers (Shows Search Tags From Google, Ask, Bing, Yahoo and the Dnn Site Search) Taxonomy Tags now contains L...Web/Cloud Applications Development Framework | Visual WebGui: 6.4 Beta 2e: Fully featured beta version of Visual WebGui Web/Cloud Applicaiton Development FrameworkWPF Behavior Library: WPF Behavior Library 0.1 Release: First alpha release of the WPF Behavior Library. It should be stable but doesn't have all of the features it will have in the future and the API ma...xvanneste: Sharepoint Social Network Client: Client permettant d'avoir accés au social network de sharepoint a l'exterieur du navigateur.Most Popular ProjectsRawrWBFS ManagerAJAX Control Toolkitpatterns & practices – Enterprise LibraryMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)iTuner - The iTunes CompanionASP.NETDotNetNuke® Community EditionMost Active ProjectsIonics Isapi Rewrite Filterpatterns & practices – Enterprise LibraryRawrHydroServer - CUAHSI Hydrologic Information System ServerAJAX Control Frameworkpatterns & practices: Azure Security GuidanceTinyProjectBlogEngine.NETNB_Store - Free DotNetNuke Ecommerce Catalog ModuleDambach Linear Algebra Framework

  Read the article

• Mocking the Unmockable: Using Microsoft Moles with Gallio

  - by Thomas Weller

  Usual opensource mocking frameworks (like e.g. Moq or Rhino.Mocks) can mock only interfaces and virtual methods. In contrary to that, Microsoft’s Moles framework can ‘mock’ virtually anything, in that it uses runtime instrumentation to inject callbacks in the method MSIL bodies of the moled methods. Therefore, it is possible to detour any .NET method, including non-virtual/static methods in sealed types. This can be extremely helpful when dealing e.g. with code that calls into the .NET framework, some third-party or legacy stuff etc… Some useful collected resources (links to website, documentation material and some videos) can be found in my toolbox on Delicious under this link: http://delicious.com/thomasweller/toolbox+moles A Gallio extension for Moles Originally, Moles is a part of Microsoft’s Pex framework and thus integrates best with Visual Studio Unit Tests (MSTest). However, the Moles sample download contains some additional assemblies to also support other unit test frameworks. They provide a Moled attribute to ease the usage of mole types with the respective framework (there are extensions for NUnit, xUnit.net and MbUnit v2 included with the samples). As there is no such extension for the Gallio platform, I did the few required lines myself – the resulting Gallio.Moles.dll is included with the sample download. With this little assembly in place, it is possible to use Moles with Gallio like that: [Test, Moled] public void SomeTest() {     ... What you can do with it Moles can be very helpful, if you need to ‘mock’ something other than a virtual or interface-implementing method. This might be the case when dealing with some third-party component, legacy code, or if you want to ‘mock’ the .NET framework itself. Generally, you need to announce each moled type that you want to use in a test with the MoledType attribute on assembly level. For example: [assembly: MoledType(typeof(System.IO.File))] Below are some typical use cases for Moles. For a more detailed overview (incl. naming conventions and an instruction on how to create the required moles assemblies), please refer to the reference material above.  Detouring the .NET framework Imagine that you want to test a method similar to the one below, which internally calls some framework method:   public void ReadFileContent(string fileName) {     this.FileContent = System.IO.File.ReadAllText(fileName); } Using a mole, you would replace the call to the File.ReadAllText(string) method with a runtime delegate like so: [Test, Moled] [Description("This 'mocks' the System.IO.File class with a custom delegate.")] public void ReadFileContentWithMoles() {     // arrange ('mock' the FileSystem with a delegate)     System.IO.Moles.MFile.ReadAllTextString = (fname => fname == FileName ? FileContent : "WrongFileName");       // act     var testTarget = new TestTarget.TestTarget();     testTarget.ReadFileContent(FileName);       // assert     Assert.AreEqual(FileContent, testTarget.FileContent); } Detouring static methods and/or classes A static method like the below… public static string StaticMethod(int x, int y) {     return string.Format("{0}{1}", x, y); } … can be ‘mocked’ with the following: [Test, Moled] public void StaticMethodWithMoles() {     MStaticClass.StaticMethodInt32Int32 = ((x, y) => "uups");       var result = StaticClass.StaticMethod(1, 2);       Assert.AreEqual("uups", result); } Detouring constructors You can do this delegate thing even with a class’ constructor. The syntax for this is not all  too intuitive, because you have to setup the internal state of the mole, but generally it works like a charm. For example, to replace this c’tor… public class ClassWithCtor {     public int Value { get; private set; }       public ClassWithCtor(int someValue)     {         this.Value = someValue;     } } … you would do the following: [Test, Moled] public void ConstructorTestWithMoles() {     MClassWithCtor.ConstructorInt32 =            ((@class, @value) => new MClassWithCtor(@class) {ValueGet = () => 99});       var classWithCtor = new ClassWithCtor(3);       Assert.AreEqual(99, classWithCtor.Value); } Detouring abstract base classes You can also use this approach to ‘mock’ abstract base classes of a class that you call in your test. Assumed that you have something like that: public abstract class AbstractBaseClass {     public virtual string SaySomething()     {         return "Hello from base.";     } }      public class ChildClass : AbstractBaseClass {     public override string SaySomething()     {         return string.Format(             "Hello from child. Base says: '{0}'",             base.SaySomething());     } } Then you would set up the child’s underlying base class like this: [Test, Moled] public void AbstractBaseClassTestWithMoles() {     ChildClass child = new ChildClass();     new MAbstractBaseClass(child)         {                 SaySomething = () => "Leave me alone!"         }         .InstanceBehavior = MoleBehaviors.Fallthrough;       var hello = child.SaySomething();       Assert.AreEqual("Hello from child. Base says: 'Leave me alone!'", hello); } Setting the moles behavior to a value of  MoleBehaviors.Fallthrough causes the ‘original’ method to be called if a respective delegate is not provided explicitly – here it causes the ChildClass’ override of the SaySomething() method to be called. There are some more possible scenarios, where the Moles framework could be of much help (e.g. it’s also possible to detour interface implementations like IEnumerable<T> and such…). One other possibility that comes to my mind (because I’m currently dealing with that), is to replace calls from repository classes to the ADO.NET Entity Framework O/R mapper with delegates to isolate the repository classes from the underlying database, which otherwise would not be possible… Usage Since Moles relies on runtime instrumentation, mole types must be run under the Pex profiler. This only works from inside Visual Studio if you write your tests with MSTest (Visual Studio Unit Test). While other unit test frameworks generally can be used with Moles, they require the respective tests to be run via command line, executed through the moles.runner.exe tool. A typical test execution would be similar to this: moles.runner.exe <mytests.dll> /runner:<myframework.console.exe> /args:/<myargs> So, the moled test can be run through tools like NCover or a scripting tool like MSBuild (which makes them easy to run in a Continuous Integration environment), but they are somewhat unhandy to run in the usual TDD workflow (which I described in some detail here). To make this a bit more fluent, I wrote a ReSharper live template to generate the respective command line for the test (it is also included in the sample download – moled_cmd.xml). - This is just a quick-and-dirty ‘solution’. Maybe it makes sense to write an extra Gallio adapter plugin (similar to the many others that are already provided) and include it with the Gallio download package, if  there’s sufficient demand for it. As of now, the only way to run tests with the Moles framework from within Visual Studio is by using them with MSTest. From the command line, anything with a managed console runner can be used (provided that the appropriate extension is in place)… A typical Gallio/Moles command line (as generated by the mentioned R#-template) looks like that: "%ProgramFiles%\Microsoft Moles\bin\moles.runner.exe" /runner:"%ProgramFiles%\Gallio\bin\Gallio.Echo.exe" "Gallio.Moles.Demo.dll" /args:/r:IsolatedAppDomain /args:/filter:"ExactType:TestFixture and Member:ReadFileContentWithMoles" -- Note: When using the command line with Echo (Gallio’s console runner), be sure to always include the IsolatedAppDomain option, otherwise the tests won’t use the instrumentation callbacks! -- License issues As I already said, the free mocking frameworks can mock only interfaces and virtual methods. if you want to mock other things, you need the Typemock Isolator tool for that, which comes with license costs (Although these ‘costs’ are ridiculously low compared to the value that such a tool can bring to a software project, spending money often is a considerable gateway hurdle in real life...).  The Moles framework also is not totally free, but comes with the same license conditions as the (closely related) Pex framework: It is free for academic/non-commercial use only, to use it in a ‘real’ software project requires an MSDN Subscription (from VS2010pro on). The demo solution The sample solution (VS 2008) can be downloaded from here. It contains the Gallio.Moles.dll which provides the here described Moled attribute, the above mentioned R#-template (moled_cmd.xml) and a test fixture containing the above described use case scenarios. To run it, you need the Gallio framework (download) and Microsoft Moles (download) being installed in the default locations. Happy testing…

  Read the article

• MSCC: Scripting - Administrator's­ toolbox of magic...

  Finally, we made it to have our April meetup - in May. The most obvious explanation is the increased amount of open source and IT activities that either the MSCC, the Linux User Group of Mauritius (LUGM), or the University of Mauritius Student's Computer Club is organising. It's absolutely incredible to see the recent hype of events here on the island. And I'm loving it! Unfortunately, we also had to deal with arranging for a location this time. It was kind of an odyssey as my requests (and phone calls) haven't been answered, even though I tried it several times - well, kind of disappointing and I have to look into that for future gatherings. In my opinion, it is essential that two parameters of a community meeting are fixed as early as possible: Location, and Date and time You can't just change one or both on the very last minute. Well, this time we had to do it due to unforeseen reasons, and I apologise to any MSCC member which couldn't make it to our April meetup. Okay, lesson learned but now back to the actual meetup report ... Shortly after the meeting I placed the following statement as my first impression: "Spontaneous and improvised :) No, seriously, Ish and Dan had well prepared presentations on shell scripting, mainly focused towards Bourne Again Shell (bash), and the pros and cons of scripting versus actually writing something in a decent programming language. I thought that I could cut myself out of the equation but the demand for information about PowerShell was higher than expected..." Well, it turned out that the interest in Windows PowerShell was high, as I even got a couple of questions on it via social media networks during the evening. I also like to mention that the number of attendees went back to what I would call a "standard" number of participation. This time there were 12 craftsmen, but again a good number of First Timers. Reactions of other attendees Here are some impressions and feedback from our participants: "Enjoyed the bash and powershell (linux / windows) presentations ..." -- Nadim on event comments "He [Daniel] also showed us some syntax loopholes in Bash that could leave someone with bad code." -- Ish on MSCC – Let's talk about Scripting   Glad to see a couple of first time attendees, especially students from the university itself. Some details on the presentations MSCC: First time visit at the University of Mauritius - Phase II Engineering Tower, room 2.9 Gimme some love ... bash and other shells Ish gave a great introduction into shell scripting as he spoke about existing shell environments and a little bit about their history. Furthermore, he talked about various built-in commands, the use of coreutils, the ability to daisy-chain multiple commands using pipes, the importance of the standard I/O streams and their file descriptors in advanced scripting techniques. Combined with a couple of sample statements in the Linux terminal on Ubuntu 14.04 machine it was a solid presentation. Have a closer look at his slides - published on his blog on MSCC – Let's talk about Scripting. Oddities of scripting After the brief introduction into bash it was Daniel's turn to highlight a good number of oddities when working with shell scripts. First of all, it should be clear that scripting is not supposed for any kind of implementations in terms of software but simply to automate administrative procedures and to simplify routine jobs on a system. One of the cool oddities that he mentioned is that everything (!) in a shell is represented by strings; there are no other types like integer, float, date-time, etc. that you'd like to use in a full-fledged programming language. Let's have a look at his sample:  more to come... What's the output? As a conclusion, Daniel suggests that shell scripting should be limited but not restricted to automatic repetitive command stacks and batch jobs, startup wrapper for applications in order to set up the execution environment, and other not too sophisticated jobs. But as soon as it might involve a little bit more logic or you might rely on performance it's better to write an application in Ruby, Python, or Perl (among others of course). This is also enables the possibility to test your code properly. MSCC: Ish talking about Bourne Again Shell (bash) and shell scripting to automate regular tasks MSCC: Daniel gives an overview about the pros and cons of shell scripting versus programming MSCC: PowerShell as your scripting solution on Windows operating systems The path of the Enlightened is long ... and tough. Honestly, even though PowerShell was mentioned without any further details on the meetup's agenda, I didn't expect that there would be demand to give a presentation on Microsoft PowerShell after all. I already took this topic out of the announcement but the audience wanted to have some information. Okay, then let's see what I could do - improvised style. While my machine booted and got hooked up to the projector, I started to talk about the beginnings of PowerShell from back in 2006, and its predecessors MS DOS and Command Prompt. A throwback in history... always good for young people. As usual, Microsoft didn't get it at that time. Instead of listening to their client's needs and demands they ignored the feasibility to administrate Windows server farms without any UI tools. PowerShell is actually a result of this, and seeing that shell scripting is a common, reliable and fast way in an administrator's toolbox for decades, Microsoft had to adapt from their Microsoft Management Console (MMC) to a broader approach. It's not like shell scripting was something new; it is in daily use by alternative operating systems like AIX, HP UX, Solaris, and last but not least Linux. Most interestingly, Microsoft is very good at renovating existing architectures, and over the years PowerShell not only replaced their own combination of Command Prompt and Scripting Hosts (VBScript and CScript) but really turned into a challenging competitor on the market. The shell is easy to extend with cmdlets, and open to other Microsoft products like SQL Server, SharePoint, as well as Third-party software applications. Similar to MMC PowerShell also offers the ability to administer other machine remotely - only without a graphical user interface and therefore it's easier to automate and schedule regular tasks. Following is a sample of a PowerShell script file (extension .ps1): $strComputer = "." $colItems = get-wmiobject -class Win32_BIOS -namespace root\CIMV2 -comp $strComputer foreach ($objItem in $colItems) {write-host "BIOS Characteristics: " $objItem.BiosCharacteristicswrite-host "BIOS Version: " $objItem.BIOSVersionwrite-host "Build Number: " $objItem.BuildNumberwrite-host "Caption: " $objItem.Captionwrite-host "Code Set: " $objItem.CodeSetwrite-host "Current Language: " $objItem.CurrentLanguagewrite-host "Description: " $objItem.Descriptionwrite-host "Identification Code: " $objItem.IdentificationCodewrite-host "Installable Languages: " $objItem.InstallableLanguageswrite-host "Installation Date: " $objItem.InstallDatewrite-host "Language Edition: " $objItem.LanguageEditionwrite-host "List Of Languages: " $objItem.ListOfLanguageswrite-host "Manufacturer: " $objItem.Manufacturerwrite-host "Name: " $objItem.Namewrite-host "Other Target Operating System: " $objItem.OtherTargetOSwrite-host "Primary BIOS: " $objItem.PrimaryBIOSwrite-host "Release Date: " $objItem.ReleaseDatewrite-host "Serial Number: " $objItem.SerialNumberwrite-host "SMBIOS BIOS Version: " $objItem.SMBIOSBIOSVersionwrite-host "SMBIOS Major Version: " $objItem.SMBIOSMajorVersionwrite-host "SMBIOS Minor Version: " $objItem.SMBIOSMinorVersionwrite-host "SMBIOS Present: " $objItem.SMBIOSPresentwrite-host "Software Element ID: " $objItem.SoftwareElementIDwrite-host "Software Element State: " $objItem.SoftwareElementStatewrite-host "Status: " $objItem.Statuswrite-host "Target Operating System: " $objItem.TargetOperatingSystemwrite-host "Version: " $objItem.Versionwrite-host} Which gives you information about your BIOS and Windows OS. Then change the computer name to another one on your network (NetBIOS based) and run the script again. There lots of samples and tutorials at the Microsoft Script Center, and I would advise you to pay a visit over there if you are more interested in PowerShell. The Script Center provides the download links, too. Upcoming Events What are the upcoming events here in Mauritius? So far, we have the following ones (incomplete list as usual) in chronological order: Hacking Defence (14. May 2014) WebCup Maurice (7. & 8. June 2014) Developers Conference (TBA ~ July 2014) Linuxfest 2014 (TBA ~ November 2014) Hopefully, there will be more announcements during the next couple of weeks and months. If you know about any other event, like a bootcamp, a code challenge or hackathon here in Mauritius, please drop me a note in the comment section below this article. Thanks! My resume of the day Spontaneous and improvised :) The new location at the University of Mauritius turned out very well, there is plenty of space, and it could be a good choice for future meetings. Especially, having the ability to get more and more students into our IT community sounds like a great opportunity. Later during the day, I got some promising mails from Nadim regarding future sessions at the local branch of the Middlesex University. Well, we will see in the future... But for now this will be on hold until approximately October when students resume their regular studies. Anyway, it was a good experience at the university, and thanks again to the UoM Student's Computer Club that made the necessary arrangements for the MSCC!

  Read the article

• When OneTug Just Isn&rsquo;t Enough&hellip;

  - by onefloridacoder

  I stole that from the back of a T-shirt I saw at the Orlando Code Camp 2010.  This was my first code camp and my first time volunteering for an event like this as well.  It was an awesome day.  I cannot begin to count the “aaahh”, “I did-not-know I could do that”, in the crowds and for myself.  I think it was a great day of learning for everyone at all levels.  All of the presenters were different and provided great insights into the topics they were presenting.  Here’s a list of the ones that I attended. KodeFuGuru, “Pirates vs. Ninjas” He touched on many good topics to relax some of the ways we think when we are writing out code, and still looks good, readable, etc.  As he pointed out in all of his examples, we might not always realize everything that’s going on under the covers.  He exposed a bug in his own code, and verbalized the mental gymnastics he went through when he knew there was something wrong with one of his IEnumerable implementations.  For me, it was great to hear that someone else labors over these gut reactions to code quickly snapped together, to the point that we rush to the refactor stage to fix what’s bothering us – and learn.  He has some content on extension methods that was very interesting.  My “that is so cool” moment was when he swapped out AddEntity method on an entity class and used a With extension method instead.  Some of the LINQ scales fell off my eyes at that moment, and I realized my own code could be a lot more powerful (and readable) if incorporate a few of these examples at the appropriate times.  And he cautioned as well… “don’t go crazy with this stuff”, there’s a place and time for everything.  One of his examples demo’d toward the end of the talk is on his sight where he’s chaining methods together, cool stuff. Quotes I liked: “Extension Methods - Extension methods to put features back on the model type, without impacting the type.” “Favor Declarative Code” – Check out the ? and ?? operators if you’re not already using them. “Favor Fluent Code” “Avoid Pirate Ninja Zombies!  If you see one run!” I’m definitely going to be looking at “Extract Projection” when I get into VS2010. BDD 101 – Sean Chambers http://github.com/schambers This guy had a whole host of gremlins against him, final score Sean 5, Gremlins 1.  He ran the code samples from his github repo  in the code github code viewer since the PC they school gave him to use didn’t have VS installed. He did a great job of converting the grammar between BDD and TDD, and how this style of development can be used in integration tests as well as the different types of gated builds on a CI box – he didn’t go into a discussion around CI, but we could infer that it could work. Like when we use WSSF, it does cause a class explosion to happen however the amount of code per class it limit to just covering the concern at hand – no more, no less.  As in “When I as a <Role>, expect {something} to happen, because {}”  This keeps us (the developer) from gold plating our solutions and creating less waste.  He basically keeps the code that prove out the requirement to two lines of code.  Nice. He uses SpecUnit to merge this grammar into his .NET projects and gave an overview on how this ties into writing his own BDD tests.  Some folks were familiar with Given / When / Then as story acceptance criteria and here’s how he mapped it: “Given <Context>  When <Something Happens> Then <I expect...>”  There are a few base classes and overrides in the SpecUnit framework that help with setting up the context for each test which looked very handy. Successfully Running Your Own Coding Business The speaker ran through a list of items that sounded like common sense stuff LLC, banking, separating expenses, etc.  Then moved into role playing with business owners and an ISV.  That was pretty good stuff, it pays to be a good listener all of the time even if your client is sitting on the other side of the phone tearing you head off for you – but that’s all it is, and get used to it its par for the course.  Oh, yeah always answer the phone was one simple thing that you can do to move  your business forward.  But like Cory Foy tweeted this week, “If you owe me a lot of money, don’t have a message that says your away for five weeks skiing in Colorado.”  Lots of food for thought that’s on my list of “todo’s and to-don’ts”. Speaker Idol Next, I had the pleasure of helping Russ Fustino tape this part of Code Camp as my primary volunteer opportunity that day.  You remember Russ, “know the code” from the awesome Russ’ Tool Shed series.  He did a great job orchestrating and capturing the Speaker Idol finals.   So I didn’t actually miss any sessions, but was able to see three back to back in one setting.  The idol finalists gave a 10 minute talk and very deep subjects, but different styles of talks.  No one walked away empty handed for jobs very well done.  Russ has details on his site.  The pictures and  video captured is supposed to be published on Channel 9 at a later date.  It was also a valuable experience to see what makes technical speakers effective in their talks.  I picked up quite a few speaking tips from what I heard from the judges and contestants. Design For Developers – Diane Leeper If you are a great developer, you’re probably a lousy designer.  Diane didn’t come to poke holes in what we think we can do with UI layout and design, but she provided some tools we can use to figure out metaphors for visualizing data.  If you need help with that check out Silverlight Pivot – that’s what she was getting at.  I was first introduced to her at one of John Papa’s talks last year at a Lakeland User Group meeting and she’s very passionate about design.  She was able to discuss different elements of Pivot, while to a developer is just looked cool. I believe she was providing the deck from her talk to folks after her talk, so send her an email if you’re interested.   She says she can talk about design for hours and hours – we all left that session believing her.   Rinse and Repeat Orlando Code Camp 2010 was awesome, and would totally do it again.  There were lots of folks from my shop there, and some that have left my shop to go elsewhere.  So it was a reunion of sorts and a great celebration for the simple fact that its great to be a developer and there’s a community that supports and recognizes it as well.  The sponsors were generous and the organizers were very tired, namely Esteban Garcia and Will Strohl who were responsible for making a lot of this magic happen.  And if you don’t believe me, check out the chatter on Twitter.

  Read the article

• CodePlex Daily Summary for Saturday, March 20, 2010

  CodePlex Daily Summary for Saturday, March 20, 2010New ProjectsaMaze Mapa Generator: Parte do Projeto aMazeASP.Net RIA Controls: Simple ASP.Net server controls to integrate Flash and Silverlight controls into your web applications. Included controls don't use any JavaScript,...BMap.NET: BMaps.NET is a .NET application written in C#, for access Bing Maps from your computer without web browsers. With it you can access to Bing Maps an...DaliNet: A .NET API for the Tridonic.Atco DALI USB device.Fabrica7: This is the main project of Fabrica 7 Corp.Image Ripper: A Winform application parse & fetch various HD pictures in specific photo galleries.IoCWrap: Provides interfaces which wrap various IoC container implementations so that it is possible to switch to a different provider without changing any ...NetSockets: NetSockets is a .NET class library that provides easy-to-use, multi-threaded, event-based, client and server network communication.Network Backup: Network Backup is a home and small company backup solution for workstations and a backup server. It incorporates a backup service, scheduler, data ...NUnit.Specs: Specification extensions for NUnit.Nutrivida: Sistema para avaliação de especialização.OHTB Snake: OHTB Snake is a multiplayer game. In this incarnation, snakes may eat 3 types of powerups: standard berries, causing them to grow; sawberries, caus...Playground TDrouen: Tjerk's PlaygroundPower Plan Chooser: This is my first endeavor into a C# Windows application with XAML. The program sits in the notification area (task bar) and lets you quickly activa...Search IMDB in C#: In lack of an IMDB API most of us resort to screen scraping utilities to query the Internet Movie Database. This one is written in C# (.NET 2.0 sta...SIGPRO Desktop: FUNCERNSql2008 PerfMonCounter Fix: Small console application to Fix the SQL 2008 Express Edition installation error: Pequena aplicação para Corrigir o seguinte erro de Instalação do...TwiztedTracker: TwiztedTracker designed to make your bug tracking easy.UmbracoXsltLogHelper: I needed a way to easily add log rows from my xslt macros, and added a single-line-extension for that reason. Then I played around with the umbraco...VisualStock: VisualStock is stock data visualization, analysis application build on the Micorsoft Composite Application Library.WHS File Mover: A Windows Home Server Plugin to move files from a local directory ("drop" or "staging" directory to a folder share)XML based Content Deployment in SharePoint: XML based Content Deployment in Sharepoint helps you to easy deploy content into SharePoint, including webs, lists, items, files and folder. You wi...New ReleasesASP.Net RIA Controls: Version 1.0 Beta: The first functionnal version.BMap.NET: BMap.NET 1: This is the 1st version of BMap.NETDigital Media Processing Project 1: Image Processor: Image Processor 1.0: All features implemented. Added: clipping imageFamily Tree Analyzer: Version 1.3.1.0: Version 1.3.1.0 Added a cancel button to marriage and children IGI Searches Opening Results window now automatically shows first record Updated IGI...Free Silverlight & WPF Chart Control - Visifire: Visifire SL and WPF Charts 3.0.5 Released: Hi, This release contains fix for the following bug: * Chart threw exception if ZoomingEnabled property was set to True at real-time. You ca...Homework Helper: Homework Helper v.1.1: Sorry but the latest release didn't seem to be the latest. This should be the right one!Image Ripper: Image Ripper: Image Ripper based on HtmlAgilityPack and GData library.ManPowerEngine: 0.1: UpdatesSound System added. Bitmap Collider in Physics System works now. Improved the performance of HTTP download in images Physics Framework...NIPO Data Processing Component Framework: NIPO 1.0: The first release of NIPO. Includes the NIPO binary dll and documentation. This release does not include a starter application since it is still in...patterns & practices SharePoint Guidance: SPG2010 Drop7: SharePoint Guidance Drop Notes Microsoft patterns and practices ****************************************** ***************************************...Photosynth Point Cloud Exporter: Photosynth Point Cloud Exporter 1.0.2: Photosynth webservice reference updated to work with the new site OBJ file format support added (Note: this format doesn't support vertex colors)Power Plan Chooser: Power Plan Chooser 1.0.0: Power Plan Chooser is a small utility that sits in the notification area (task bar) in Windows 7 and allows the user to quickly activate one of the...Restart Explorer: RestartExplorer Release 1.00.0001: Initial release: Start, stop and restart Windows Explorer with this utility.Search IMDB in C#: Search IMDB 1.0: Source code included with compiled example.SIMD Detector: 3rd Release: Added Intel AES instruction check Added a CSharp Winform NetSIMDDetector application. Changes the red ball and green ball images to red cross a...Sql2008 PerfMonCounter Fix: Sql2008FIx_PerfMonCounter.zip: Small console application to Fix the SQL 2008 Express Edition installation error: http://support.microsoft.com/kb/300956 Rule Name PerfMonCounter...UmbracoXsltLogHelper: 0.9 Working Beta: First version. XsltLogHelper09 is the installable package.VCC: Latest build, v2.1.30319.0: Automatic drop of latest buildWCF RIA Services Contrib: RIA Services Contrib RC Release: This version is recompiled against the RC release of WCF RIA Services.XML based Content Deployment in SharePoint: SPContentDeployment 1.0.0.0: The first link contains the resources and a sample project. The second link contains everything included in the first package and an additional fo...Yet Another GPS: YAGPS Alfa.2: Yet another GPS tracker is a very powerful GPS track application for Windows Mobile Speed Guage, Sat Count number, KML for google map file formatZGuideTV.NET: ZGuideTV.NET 0.92: Vendredi 19 mars 2010 (ZGuideTV.NET bêta 9 build 0.92) - English below Corrections : - Gestion de certains contrôles dans l'écran principal. - Div...Most Popular ProjectsMetaSharpRawrWBFS ManagerSilverlight ToolkitASP.NET Ajax LibraryMicrosoft SQL Server Product Samples: DatabaseAJAX Control ToolkitLiveUpload to FacebookWindows Presentation Foundation (WPF)ASP.NETMost Active ProjectsLINQ to TwitterRawrOData SDK for PHPjQuery Library for SharePoint Web ServicesDirectQPHPExcelpatterns & practices – Enterprise LibraryBlogEngine.NETFarseer Physics EngineNB_Store - Free DotNetNuke Ecommerce Catalog Module

  Read the article

< Previous Page | 53 54 55 56 57 58 59 60 61 62 63 64  | Next Page >