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  • Deploy ASP.NET Web Applications with Web Deployment Projects

    - by Ben Griswold
    One may quickly build and deploy an ASP.NET web application via the Publish option in Visual Studio.  This option works great for most simple deployment scenarios but it won’t always cut it.  Let’s say you need to automate your deployments. Or you have environment-specific configuration settings. Or you need to execute pre/post build operations when you do your builds.  If so, you should consider using Web Deployment Projects. The Web Deployment Project type doesn’t come out-of-the-box with Visual Studio 2008.  You’ll need to Download Visual Studio® 2008 Web Deployment Projects – RTW and install if you want to follow along with this tutorial. I’ve created a shiny new ASP.NET MVC project.  Web Deployment Projects work with websites, web applications and MVC projects so feel free to go with any web project type you’d like.  Once your web application is in place, it’s time to add the Web Deployment project.  You can hunt and peck around the File > New > New Project… dialogue as long as you’d like, but you aren’t going to find what you need.  Instead, select the web project and then choose the “Add Web Deployment Project…” hiding behind the Build menu option. I prefer to name my projects based on the environment in which I plan to deploy.  In this case, I’ll be rolling to the QA machine. Don’t expect too much to happen at this point.  A seemingly empty project with a funny icon will be added to your solution.  That’s it. I want to take a minute and talk about configuration settings before we continue.  Some of the common settings which might change from environment to environment are appSettings, connectionStrings and mailSettings.  Here’s a look at my updated web.config: <appSettings>   <add key="MvcApplication293.Url" value="http://localhost:50596/" />     </appSettings> <connectionStrings>   <add name="ApplicationServices"        connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true"        providerName="System.Data.SqlClient"/> </connectionStrings>   <system.net>   <mailSettings>     <smtp from="[email protected]">         <network host="server.com" userName="username" password="password" port="587" defaultCredentials="false"/>     </smtp>   </mailSettings> </system.net> I want to update these values prior to deploying to the QA environment.  There are variations to this approach, but I like to maintain environment-specific settings for each of the web.config sections in the Config/[Environment] project folders.  I’ve provided a screenshot of the QA environment settings below. It may be obvious what one should include in each of the three files.  Basically, it is a copy of the associated web.config section with updated setting values.  For example, the AppSettings.config file may include a reference to the QA web url, the DB.config would include the QA database server and login information and the StmpSettings.config would include a QA Stmp server and user information. <?xml version="1.0" encoding="utf-8" ?> <appSettings>   <add key="MvcApplication293.Url" value="http://qa.MvcApplicatinon293.com/" /> </appSettings> AppSettings.config  <?xml version="1.0" encoding="utf-8" ?> <connectionStrings>   <add name="ApplicationServices"        connectionString="server=QAServer;integrated security=SSPI;database=MvcApplication293"        providerName="System.Data.SqlClient"/>   </connectionStrings> Db.config  <?xml version="1.0" encoding="utf-8" ?> <smtp from="[email protected]">     <network host="qaserver.com" userName="qausername" password="qapassword" port="587" defaultCredentials="false"/> </smtp> SmtpSettings.config  I think our web project is ready to deploy.  Now, it’s time to concentrate on the Web Deployment Project itself.  Right-click on the project file and open the Property Pages. The first thing to call out is the Configuration dropdown.  I only deploy a project which is built in Release Mode so I only setup the Web Deployment Project for this mode.  (This is when you change the Configuration selection to “Release.”)  I typically keep the Output Folder default value – .\Release\.  When the application is built, all artifacts will be dropped in the .\Release\ folder relative to the Web Deployment Project root.  The final option may be up for some debate.  I like to roll out updatable websites so I select the “Allow this precompiled site to be updatable” option.  I really do like to follow standard SDLC processes when I release my software but there are those times when you just have to make a hotfix to production and I like to keep this option open if need be.  If you are strongly opposed to this idea, please, by all means, don’t check the box. The next tab is boring.  I don’t like to deploy a crazy number of DLLs so I merge all outputs to a single assembly.  Again, you may have another option and feel free to change this selection if you so wish. If you follow my lead, take care when choosing a single assembly name.  The Assembly Name can not be the same as the website or any other project in your solution otherwise you’ll receive a circular reference build error.  In other words, I can’t name the assembly MvcApplication293 or my output window would start yelling at me. Remember when we called out our QA configuration files?  Click on the Deployment tab and you’ll see how where going to use them.  Notice the Web.config file section replacements value.  All this does is swap called out web.config sections with the content of the Config\QA\* files.  You can reduce or extend this list as you deem fit.  Did you see the “Use external configuration source file” option?  You know how you can point any of your web.config sections to an external file via the configSource attribute?  This option allows you to leverage that technique and instead of replacing the content of the sections, you will replace the configSource attribute value instead. <appSettings configSource="Config\QA\AppSettings.config" /> Go ahead and Apply your changes.  I’d like to take a look at the project file we just updated.  Right-click on the Web Deployment Project and select “Open Project File.” One of the first configuration blocks reflects core Release build settings.  There are a couple of points I’d like to call out here: DebugSymbols=false ensures the compilation debug attribute in your web.config is flipped to false as part of build process.  There’s some crumby (more likely old) documentation which implies you need a ToggleDebugCompilation task to make this happen.  Nope. Just make sure the DebugSymbols is set to false.  EnableUpdateable implies a single dll for the web application rather than a dll for each object and and empty view file. I think updatable applications are cleaner and include the benefit (or risk based on your perspective) that portions of the application can be updated directly on the server.  I called this out earlier but I wanted to reiterate. <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">     <DebugSymbols>false</DebugSymbols>     <OutputPath>.\Release</OutputPath>     <EnableUpdateable>true</EnableUpdateable>     <UseMerge>true</UseMerge>     <SingleAssemblyName>MvcApplication293</SingleAssemblyName>     <DeleteAppCodeCompiledFiles>true</DeleteAppCodeCompiledFiles>     <UseWebConfigReplacement>true</UseWebConfigReplacement>     <ValidateWebConfigReplacement>true</ValidateWebConfigReplacement>     <DeleteAppDataFolder>true</DeleteAppDataFolder>   </PropertyGroup> The next section is self-explanatory.  The content merely reflects the replacement value you provided via the Property Pages. <ItemGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'">     <WebConfigReplacementFiles Include="Config\QA\AppSettings.config">       <Section>appSettings</Section>     </WebConfigReplacementFiles>     <WebConfigReplacementFiles Include="Config\QA\Db.config">       <Section>connectionStrings</Section>     </WebConfigReplacementFiles>     <WebConfigReplacementFiles Include="Config\QA\SmtpSettings.config">       <Section>system.net/mailSettings/smtp</Section>     </WebConfigReplacementFiles>   </ItemGroup> You’ll want to extend the ItemGroup section to include the files you wish to exclude from the build.  The sample ExcludeFromBuild nodes exclude all obj, svn, csproj, user, pdb artifacts from the build. Enough though they files aren’t included in your web project, you’ll need to exclude them or they’ll show up along with required deployment artifacts.  <ItemGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'">     <WebConfigReplacementFiles Include="Config\QA\AppSettings.config">       <Section>appSettings</Section>     </WebConfigReplacementFiles>     <WebConfigReplacementFiles Include="Config\QA\Db.config">       <Section>connectionStrings</Section>     </WebConfigReplacementFiles>     <WebConfigReplacementFiles Include="Config\QA\SmtpSettings.config">       <Section>system.net/mailSettings/smtp</Section>     </WebConfigReplacementFiles>     <ExcludeFromBuild Include="$(SourceWebPhysicalPath)\obj\**\*.*" />     <ExcludeFromBuild Include="$(SourceWebPhysicalPath)\**\.svn\**\*.*" />     <ExcludeFromBuild Include="$(SourceWebPhysicalPath)\**\.svn\**\*" />     <ExcludeFromBuild Include="$(SourceWebPhysicalPath)\**\*.csproj" />     <ExcludeFromBuild Include="$(SourceWebPhysicalPath)\**\*.user" />     <ExcludeFromBuild Include="$(SourceWebPhysicalPath)\bin\*.pdb" />     <ExcludeFromBuild Include="$(SourceWebPhysicalPath)\Notes.txt" />   </ItemGroup> Pre/post build and Pre/post merge tasks are added to the final code block.  By default, your project file should look like the following – a completely commented out section. <!– To modify your build process, add your task inside one of        the targets below and uncomment it. Other similar extension        points exist, see Microsoft.WebDeployment.targets.   <Target Name="BeforeBuild">   </Target>   <Target Name="BeforeMerge">   </Target>   <Target Name="AfterMerge">   </Target>   <Target Name="AfterBuild">   </Target>   –> Update the section to remove all temporary Config folders and files after the build.  <!– To modify your build process, add your task inside one of        the targets below and uncomment it. Other similar extension        points exist, see Microsoft.WebDeployment.targets.     <Target Name="BeforeMerge">   </Target>   <Target Name="AfterMerge">   </Target>     <Target Name="BeforeBuild">      </Target>       –>   <Target Name="AfterBuild">     <!– WebConfigReplacement requires the Config files. Remove after build. –>     <RemoveDir Directories="$(OutputPath)\Config" />   </Target> That’s it for setup.  Save the project file, flip the solution to Release Mode and build.  If there’s an issue, consult the Output window for details.  If all went well, you will find your deployment artifacts in your Web Deployment Project folder like so. Both the code source and published application will be there. Inside the Release folder you will find your “published files” and you’ll notice the Config folder is no where to be found.  In the Source folder, all project files are found with the exception of the items which were excluded from the build. I’ll wrap up this tutorial by calling out a little Web Deployment pet peeve of mine: there doesn’t appear to be a way to add an existing web deployment project to a solution.  The best I can come up with is create a new web deployment project and then copy and paste the contents of the existing project file into the new project file.  It’s not a big deal but it bugs me. Download the Solution

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  • ANTS CLR and Memory Profiler In Depth Review (Part 1 of 2 &ndash; CLR Profiler)

    - by ToStringTheory
    One of the things that people might not know about me, is my obsession to make my code as efficient as possible.  Many people might not realize how much of a task or undertaking that this might be, but it is surely a task as monumental as climbing Mount Everest, except this time it is a challenge for the mind…  In trying to make code efficient, there are many different factors that play a part – size of project or solution, tiers, language used, experience and training of the programmer, technologies used, maintainability of the code – the list can go on for quite some time. I spend quite a bit of time when developing trying to determine what is the best way to implement a feature to accomplish the efficiency that I look to achieve.  One program that I have recently come to learn about – Red Gate ANTS Performance (CLR) and Memory profiler gives me tools to accomplish that job more efficiently as well.  In this review, I am going to cover some of the features of the ANTS profiler set by compiling some hideous example code to test against. Notice As a member of the Geeks With Blogs Influencers program, one of the perks is the ability to review products, in exchange for a free license to the program.  I have not let this affect my opinions of the product in any way, and Red Gate nor Geeks With Blogs has tried to influence my opinion regarding this product in any way. Introduction The ANTS Profiler pack provided by Red Gate was something that I had not heard of before receiving an email regarding an offer to review it for a license.  Since I look to make my code efficient, it was a no brainer for me to try it out!  One thing that I have to say took me by surprise is that upon downloading the program and installing it you fill out a form for your usual contact information.  Sure enough within 2 hours, I received an email from a sales representative at Red Gate asking if she could help me to achieve the most out of my trial time so it wouldn’t go to waste.  After replying to her and explaining that I was looking to review its feature set, she put me in contact with someone that setup a demo session to give me a quick rundown of its features via an online meeting.  After having dealt with a massive ordeal with one of my utility companies and their complete lack of customer service, Red Gates friendly and helpful representatives were a breath of fresh air, and something I was thankful for. ANTS CLR Profiler The ANTS CLR profiler is the thing I want to focus on the most in this post, so I am going to dive right in now. Install was simple and took no time at all.  It installed both the profiler for the CLR and Memory, but also visual studio extensions to facilitate the usage of the profilers (click any images for full size images): The Visual Studio menu options (under ANTS menu) Starting the CLR Performance Profiler from the start menu yields this window If you follow the instructions after launching the program from the start menu (Click File > New Profiling Session to start a new project), you are given a dialog with plenty of options for profiling: The New Session dialog.  Lots of options.  One thing I noticed is that the buttons in the lower right were half-covered by the panel of the application.  If I had to guess, I would imagine that this is caused by my DPI settings being set to 125%.  This is a problem I have seen in other applications as well that don’t scale well to different dpi scales. The profiler options give you the ability to profile: .NET Executable ASP.NET web application (hosted in IIS) ASP.NET web application (hosted in IIS express) ASP.NET web application (hosted in Cassini Web Development Server) SharePoint web application (hosted in IIS) Silverlight 4+ application Windows Service COM+ server XBAP (local XAML browser application) Attach to an already running .NET 4 process Choosing each option provides a varying set of other variables/options that one can set including options such as application arguments, operating path, record I/O performance performance counters to record (43 counters in all!), etc…  All in all, they give you the ability to profile many different .Net project types, and make it simple to do so.  In most cases of my using this application, I would be using the built in Visual Studio extensions, as they automatically start a new profiling project in ANTS with the options setup, and start your program, however RedGate has made it easy enough to profile outside of Visual Studio as well. On the flip side of this, as someone who lives most of their work life in Visual Studio, one thing I do wish is that instead of opening an entirely separate application/gui to perform profiling after launching, that instead they would provide a Visual Studio panel with the information, and integrate more of the profiling project information into Visual Studio.  So, now that we have an idea of what options that the profiler gives us, its time to test its abilities and features. Horrendous Example Code – Prime Number Generator One of my interests besides development, is Physics and Math – what I went to college for.  I have especially always been interested in prime numbers, as they are something of a mystery…  So, I decided that I would go ahead and to test the abilities of the profiler, I would write a small program, website, and library to generate prime numbers in the quantity that you ask for.  I am going to start off with some terrible code, and show how I would see the profiler being used as a development tool. First off, the IPrimes interface (all code is downloadable at the end of the post): interface IPrimes { IEnumerable<int> GetPrimes(int retrieve); } Simple enough, right?  Anything that implements the interface will (hopefully) provide an IEnumerable of int, with the quantity specified in the parameter argument.  Next, I am going to implement this interface in the most basic way: public class DumbPrimes : IPrimes { public IEnumerable<int> GetPrimes(int retrieve) { //store a list of primes already found var _foundPrimes = new List<int>() { 2, 3 }; //if i ask for 1 or two primes, return what asked for if (retrieve <= _foundPrimes.Count()) return _foundPrimes.Take(retrieve); //the next number to look at int _analyzing = 4; //since I already determined I don't have enough //execute at least once, and until quantity is sufficed do { //assume prime until otherwise determined bool isPrime = true; //start dividing at 2 //divide until number is reached, or determined not prime for (int i = 2; i < _analyzing && isPrime; i++) { //if (i) goes into _analyzing without a remainder, //_analyzing is NOT prime if (_analyzing % i == 0) isPrime = false; } //if it is prime, add to found list if (isPrime) _foundPrimes.Add(_analyzing); //increment number to analyze next _analyzing++; } while (_foundPrimes.Count() < retrieve); return _foundPrimes; } } This is the simplest way to get primes in my opinion.  Checking each number by the straight definition of a prime – is it divisible by anything besides 1 and itself. I have included this code in a base class library for my solution, as I am going to use it to demonstrate a couple of features of ANTS.  This class library is consumed by a simple non-MVVM WPF application, and a simple MVC4 website.  I will not post the WPF code here inline, as it is simply an ObservableCollection<int>, a label, two textbox’s, and a button. Starting a new Profiling Session So, in Visual Studio, I have just completed my first stint developing the GUI and DumbPrimes IPrimes class, so now I want to check my codes efficiency by profiling it.  All I have to do is build the solution (surprised initiating a profiling session doesn’t do this, but I suppose I can understand it), and then click the ANTS menu, followed by Profile Performance.  I am then greeted by the profiler starting up and already monitoring my program live: You are provided with a realtime graph at the top, and a pane at the bottom giving you information on how to proceed.  I am going to start by asking my program to show me the first 15000 primes: After the program finally began responding again (I did all the work on the main UI thread – how bad!), I stopped the profiler, which did kill the process of my program too.  One important thing to note, is that the profiler by default wants to give you a lot of detail about the operation – line hit counts, time per line, percent time per line, etc…  The important thing to remember is that this itself takes a lot of time.  When running my program without the profiler attached, it can generate the 15000 primes in 5.18 seconds, compared to 74.5 seconds – almost a 1500 percent increase.  While this may seem like a lot, remember that there is a trade off.  It may be WAY more inefficient, however, I am able to drill down and make improvements to specific problem areas, and then decrease execution time all around. Analyzing the Profiling Session After clicking ‘Stop Profiling’, the process running my application stopped, and the entire execution time was automatically selected by ANTS, and the results shown below: Now there are a number of interesting things going on here, I am going to cover each in a section of its own: Real Time Performance Counter Bar (top of screen) At the top of the screen, is the real time performance bar.  As your application is running, this will constantly update with the currently selected performance counters status.  A couple of cool things to note are the fact that you can drag a selection around specific time periods to drill down the detail views in the lower 2 panels to information pertaining to only that period. After selecting a time period, you can bookmark a section and name it, so that it is easy to find later, or after reloaded at a later time.  You can also zoom in, out, or fit the graph to the space provided – useful for drilling down. It may be hard to see, but at the top of the processor time graph below the time ticks, but above the red usage graph, there is a green bar. This bar shows at what times a method that is selected in the ‘Call tree’ panel is called. Very cool to be able to click on a method and see at what times it made an impact. As I said before, ANTS provides 43 different performance counters you can hook into.  Click the arrow next to the Performance tab at the top will allow you to change between different counters if you have them selected: Method Call Tree, ADO.Net Database Calls, File IO – Detail Panel Red Gate really hit the mark here I think. When you select a section of the run with the graph, the call tree populates to fill a hierarchical tree of method calls, with information regarding each of the methods.   By default, methods are hidden where the source is not provided (framework type code), however, Red Gate has integrated Reflector into ANTS, so even if you don’t have source for something, you can select a method and get the source if you want.  Methods are also hidden where the impact is seen as insignificant – methods that are only executed for 1% of the time of the overall calling methods time; in other words, working on making them better is not where your efforts should be focused. – Smart! Source Panel – Detail Panel The source panel is where you can see line level information on your code, showing the code for the currently selected method from the Method Call Tree.  If the code is not available, Reflector takes care of it and shows the code anyways! As you can notice, there does seem to be a problem with how ANTS determines what line is the actual line that a call is completed on.  I have suspicions that this may be due to some of the inline code optimizations that the CLR applies upon compilation of the assembly.  In a method with comments, the problem is much more severe: As you can see here, apparently the most offending code in my base library was a comment – *gasp*!  Removing the comments does help quite a bit, however I hope that Red Gate works on their counter algorithm soon to improve the logic on positioning for statistics: I did a small test just to demonstrate the lines are correct without comments. For me, it isn’t a deal breaker, as I can usually determine the correct placements by looking at the application code in the region and determining what makes sense, but it is something that would probably build up some irritation with time. Feature – Suggest Method for Optimization A neat feature to really help those in need of a pointer, is the menu option under tools to automatically suggest methods to optimize/improve: Nice feature – clicking it filters the call tree and stars methods that it thinks are good candidates for optimization.  I do wish that they would have made it more visible for those of use who aren’t great on sight: Process Integration I do think that this could have a place in my process.  After experimenting with the profiler, I do think it would be a great benefit to do some development, testing, and then after all the bugs are worked out, use the profiler to check on things to make sure nothing seems like it is hogging more than its fair share.  For example, with this program, I would have developed it, ran it, tested it – it works, but slowly. After looking at the profiler, and seeing the massive amount of time spent in 1 method, I might go ahead and try to re-implement IPrimes (I actually would probably rewrite the offending code, but so that I can distribute both sets of code easily, I’m just going to make another implementation of IPrimes).  Using two pieces of knowledge about prime numbers can make this method MUCH more efficient – prime numbers fall into two buckets 6k+/-1 , and a number is prime if it is not divisible by any other primes before it: public class SmartPrimes : IPrimes { public IEnumerable<int> GetPrimes(int retrieve) { //store a list of primes already found var _foundPrimes = new List<int>() { 2, 3 }; //if i ask for 1 or two primes, return what asked for if (retrieve <= _foundPrimes.Count()) return _foundPrimes.Take(retrieve); //the next number to look at int _k = 1; //since I already determined I don't have enough //execute at least once, and until quantity is sufficed do { //assume prime until otherwise determined bool isPrime = true; int potentialPrime; //analyze 6k-1 //assign the value to potential potentialPrime = 6 * _k - 1; //if there are any primes that divise this, it is NOT a prime number //using PLINQ for quick boost isPrime = !_foundPrimes.AsParallel() .Any(prime => potentialPrime % prime == 0); //if it is prime, add to found list if (isPrime) _foundPrimes.Add(potentialPrime); if (_foundPrimes.Count() == retrieve) break; //analyze 6k+1 //assign the value to potential potentialPrime = 6 * _k + 1; //if there are any primes that divise this, it is NOT a prime number //using PLINQ for quick boost isPrime = !_foundPrimes.AsParallel() .Any(prime => potentialPrime % prime == 0); //if it is prime, add to found list if (isPrime) _foundPrimes.Add(potentialPrime); //increment k to analyze next _k++; } while (_foundPrimes.Count() < retrieve); return _foundPrimes; } } Now there are definitely more things I can do to help make this more efficient, but for the scope of this example, I think this is fine (but still hideous)! Profiling this now yields a happy surprise 27 seconds to generate the 15000 primes with the profiler attached, and only 1.43 seconds without.  One important thing I wanted to call out though was the performance graph now: Notice anything odd?  The %Processor time is above 100%.  This is because there is now more than 1 core in the operation.  A better label for the chart in my mind would have been %Core time, but to each their own. Another odd thing I noticed was that the profiler seemed to be spot on this time in my DumbPrimes class with line details in source, even with comments..  Odd. Profiling Web Applications The last thing that I wanted to cover, that means a lot to me as a web developer, is the great amount of work that Red Gate put into the profiler when profiling web applications.  In my solution, I have a simple MVC4 application setup with 1 page, a single input form, that will output prime values as my WPF app did.  Launching the profiler from Visual Studio as before, nothing is really different in the profiler window, however I did receive a UAC prompt for a Red Gate helper app to integrate with the web server without notification. After requesting 500, 1000, 2000, and 5000 primes, and looking at the profiler session, things are slightly different from before: As you can see, there are 4 spikes of activity in the processor time graph, but there is also something new in the call tree: That’s right – ANTS will actually group method calls by get/post operations, so it is easier to find out what action/page is giving the largest problems…  Pretty cool in my mind! Overview Overall, I think that Red Gate ANTS CLR Profiler has a lot to offer, however I think it also has a long ways to go.  3 Biggest Pros: Ability to easily drill down from time graph, to method calls, to source code Wide variety of counters to choose from when profiling your application Excellent integration/grouping of methods being called from web applications by request – BRILLIANT! 3 Biggest Cons: Issue regarding line details in source view Nit pick – Processor time vs. Core time Nit pick – Lack of full integration with Visual Studio Ratings Ease of Use (7/10) – I marked down here because of the problems with the line level details and the extra work that that entails, and the lack of better integration with Visual Studio. Effectiveness (10/10) – I believe that the profiler does EXACTLY what it purports to do.  Especially with its large variety of performance counters, a definite plus! Features (9/10) – Besides the real time performance monitoring, and the drill downs that I’ve shown here, ANTS also has great integration with ADO.Net, with the ability to show database queries run by your application in the profiler.  This, with the line level details, the web request grouping, reflector integration, and various options to customize your profiling session I think create a great set of features! Customer Service (10/10) – My entire experience with Red Gate personnel has been nothing but good.  their people are friendly, helpful, and happy! UI / UX (8/10) – The interface is very easy to get around, and all of the options are easy to find.  With a little bit of poking around, you’ll be optimizing Hello World in no time flat! Overall (8/10) – Overall, I am happy with the Performance Profiler and its features, as well as with the service I received when working with the Red Gate personnel.  I WOULD recommend you trying the application and seeing if it would fit into your process, BUT, remember there are still some kinks in it to hopefully be worked out. My next post will definitely be shorter (hopefully), but thank you for reading up to here, or skipping ahead!  Please, if you do try the product, drop me a message and let me know what you think!  I would love to hear any opinions you may have on the product. Code Feel free to download the code I used above – download via DropBox

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  • iPhone SDK vs. Windows Phone 7 Series SDK Challenge, Part 2: MoveMe

    In this series, I will be taking sample applications from the iPhone SDK and implementing them on Windows Phone 7 Series.  My goal is to do as much of an apples-to-apples comparison as I can.  This series will be written to not only compare and contrast how easy or difficult it is to complete tasks on either platform, how many lines of code, etc., but Id also like it to be a way for iPhone developers to either get started on Windows Phone 7 Series development, or for developers in general to learn the platform. Heres my methodology: Run the iPhone SDK app in the iPhone Simulator to get a feel for what it does and how it works, without looking at the implementation Implement the equivalent functionality on Windows Phone 7 Series using Silverlight. Compare the two implementations based on complexity, functionality, lines of code, number of files, etc. Add some functionality to the Windows Phone 7 Series app that shows off a way to make the scenario more interesting or leverages an aspect of the platform, or uses a better design pattern to implement the functionality. You can download Microsoft Visual Studio 2010 Express for Windows Phone CTP here, and the Expression Blend 4 Beta here. If youre seeing this series for the first time, check out Part 1: Hello World. A note on methodologyin the prior post there was some feedback about lines of code not being a very good metric for this exercise.  I dont really disagree, theres a lot more to this than lines of code but I believe that is a relevant metric, even if its not the ultimate one.  And theres no perfect answer here.  So I am going to continue to report the number of lines of code that I, as a developer would need to write in these apps as a data point, and Ill leave it up to the reader to determine how that fits in with overall complexity, etc.  The first example was so basic that I think it was difficult to talk about in real terms.  I think that as these apps get more complex, the subjective differences in concept count and will be more important.  MoveMe The MoveMe app is the main end-to-end app writing example in the iPhone SDK, called Creating an iPhone Application.  This application demonstrates a few concepts, including handling touch input, how to do animations, and how to do some basic transforms. The behavior of the application is pretty simple.  User touches the button: The button does a throb type animation where it scales up and then back down briefly. User drags the button: After a touch begins, moving the touch point will drag the button around with the touch. User lets go of the button: The button animates back to its original position, but does a few small bounces as it reaches its original point, which makes the app fun and gives it an extra bit of interactivity. Now, how would I write an app that meets this spec for Windows Phone 7 Series, and how hard would it be?  Lets find out!     Implementing the UI Okay, lets build the UI for this application.  In the HelloWorld example, we did all the UI design in Visual Studio and/or by hand in XAML.  In this example, were going to use the Expression Blend 4 Beta. You might be wondering when to use Visual Studio, when to use Blend, and when to do XAML by hand.  Different people will have different takes on this, but heres mine: XAML by hand simple UI that doesnt contain animations, gradients, etc., and or UI that I want to really optimize and craft when I know exactly what I want to do. Visual Studio Basic UI layout, property setting, data binding, etc. Blend Any serious design work needs to be done in Blend, including animations, handling states and transitions, styling and templating, editing resources. As in Part 1, go ahead and fire up Visual Studio 2010 Express for Windows Phone (yes, soon it will take longer to say the name of our products than to start them up!), and create a new Windows Phone Application.  As in Part 1, clear out the XAML from the designer.  An easy way to do this is to just: Click on the design surface Hit Control+A Hit Delete Theres a little bit left over (the Grid.RowDefinitions element), just go ahead and delete that element so were starting with a clean state of only one outer Grid element. To use Blend, we need to save this project.  See, when you create a project with Visual Studio Express, it doesnt commit it to the disk (well, in a place where you can find it, at least) until you actually save the project.  This is handy if youre doing some fooling around, because it doesnt clutter your disk with WindowsPhoneApplication23-like directories.  But its also kind of dangerous, since when you close VS, if you dont save the projectits all gone.  Yes, this has bitten me since I was saving files and didnt remember that, so be careful to save the project/solution via Save All, at least once. So, save and note the location on disk.  Start Expression Blend 4 Beta, and chose File > Open Project/Solution, and load your project.  You should see just about the same thing you saw over in VS: a blank, black designer surface. Now, thinking about this application, we dont really need a button, even though it looks like one.  We never click it.  So were just going to create a visual and use that.  This is also true in the iPhone example above, where the visual is actually not a button either but a jpg image with a nice gradient and round edges.  Well do something simple here that looks pretty good. In Blend, look in the tool pane on the left for the icon that looks like the below (the highlighted one on the left), and hold it down to get the popout menu, and choose Border:    Okay, now draw out a box in the middle of the design surface of about 300x100.  The Properties Pane to the left should show the properties for this item. First, lets make it more visible by giving it a border brush.  Set the BorderBrush to white by clicking BorderBrush and dragging the color selector all the way to the upper right in the palette.  Then, down a bit farther, make the BorderThickness 4 all the way around, and the CornerRadius set to 6. In the Layout section, do the following to Width, Height, Horizontal and Vertical Alignment, and Margin (all 4 margin values): Youll see the outline now is in the middle of the design surface.  Now lets give it a background color.  Above BorderBrush select Background, and click the third tab over: Gradient Brush.  Youll see a gradient slider at the bottom, and if you click the markers, you can edit the gradient stops individually (or add more).  In this case, you can select something you like, but wheres what I chose: Left stop: #BFACCFE2 (I just picked a spot on the palette and set opacity to 75%, no magic here, feel free to fiddle these or just enter these numbers into the hex area and be done with it) Right stop: #FF3E738F Okay, looks pretty good.  Finally set the name of the element in the Name field at the top of the Properties pane to welcome. Now lets add some text.  Just hit T and itll select the TextBlock tool automatically: Now draw out some are inside our welcome visual and type Welcome!, then click on the design surface (to exit text entry mode) and hit V to go back into selection mode (or the top item in the tool pane that looks like a mouse pointer).  Click on the text again to select it in the tool pane.  Just like the border, we want to center this.  So set HorizontalAlignment and VerticalAlignment to Center, and clear the Margins: Thats it for the UI.  Heres how it looks, on the design surface: Not bad!  Okay, now the fun part Adding Animations Using Blend to build animations is a lot of fun, and its easy.  In XAML, I can not only declare elements and visuals, but also I can declare animations that will affect those visuals.  These are called Storyboards. To recap, well be doing two animations: The throb animation when the element is touched The center animation when the element is released after being dragged. The throb animation is just a scale transform, so well do that first.  In the Objects and Timeline Pane (left side, bottom half), click the little + icon to add a new Storyboard called touchStoryboard: The timeline view will appear.  In there, click a bit to the right of 0 to create a keyframe at .2 seconds: Now, click on our welcome element (the Border, not the TextBlock in it), and scroll to the bottom of the Properties Pane.  Open up Transform, click the third tab ("Scale), and set X and Y to 1.2: This all of this says that, at .2 seconds, I want the X and Y size of this element to scale to 1.2. In fact you can see this happen.  Push the Play arrow in the timeline view, and youll see the animation run! Lets make two tweaks.  First, we want the animation to automatically reverse so it scales up then back down nicely. Click in the dropdown that says touchStoryboard in Objects and Timeline, then in the Properties pane check Auto Reverse: Now run it again, and youll see it go both ways. Lets even make it nicer by adding an easing function. First, click on the Render Transform item in the Objects tree, then, in the Property Pane, youll see a bunch of easing functions to choose from.  Feel free to play with this, then seeing how each runs.  I chose Circle In, but some other ones are fun.  Try them out!  Elastic In is kind of fun, but well stick with Circle In.  Thats it for that animation. Now, we also want an animation to move the Border back to its original position when the user ends the touch gesture.  This is exactly the same process as above, but just targeting a different transform property. Create a new animation called releaseStoryboard Select a timeline point at 1.2 seconds. Click on the welcome Border element again Scroll to the Transforms panel at the bottom of the Properties Pane Choose the first tab (Translate), which may already be selected Set both X and Y values to 0.0 (we do this just to make the values stick, because the value is already 0 and we need Blend to know we want to save that value) Click on RenderTransform in the Objects tree In the properties pane, choose Bounce Out Set Bounces to 6, and Bounciness to 4 (feel free to play with these as well) Okay, were done. Note, if you want to test this Storyboard, you have to do something a little tricky because the final value is the same as the initial value, so playing it does nothing.  If you want to play with it, do the following: Next to the selection dropdown, hit the little "x (Close Storyboard) Go to the Translate Transform value for welcome Set X,Y to 50, 200, respectively (or whatever) Select releaseStoryboard again from the dropdown Hit play, see it run Go into the object tree and select RenderTransform to change the easing function. When youre done, hit the Close Storyboard x again and set the values in Transform/Translate back to 0 Wiring Up the Animations Okay, now go back to Visual Studio.  Youll get a prompt due to the modification of MainPage.xaml.  Hit Yes. In the designer, click on the welcome Border element.  In the Property Browser, hit the Events button, then double click each of ManipulationStarted, ManipulationDelta, ManipulationCompleted.  Youll need to flip back to the designer from code, after each double click. Its code time.  Here we go. Here, three event handlers have been created for us: welcome_ManipulationStarted: This will execute when a manipulation begins.  Think of it as MouseDown. welcome_ManipulationDelta: This executes each time a manipulation changes.  Think MouseMove. welcome_ManipulationCompleted: This will  execute when the manipulation ends. Think MouseUp. Now, in ManipuliationStarted, we want to kick off the throb animation that we called touchAnimation.  Thats easy: 1: private void welcome_ManipulationStarted(object sender, ManipulationStartedEventArgs e) 2: { 3: touchStoryboard.Begin(); 4: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Likewise, when the manipulation completes, we want to re-center the welcome visual with our bounce animation: 1: private void welcome_ManipulationCompleted(object sender, ManipulationCompletedEventArgs e) 2: { 3: releaseStoryboard.Begin(); 4: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Note there is actually a way to kick off these animations from Blend directly via something called Triggers, but I think its clearer to show whats going on like this.  A Trigger basically allows you to say When this event fires, trigger this Storyboard, so its the exact same logical process as above, but without the code. But how do we get the object to move?  Well, for that we really dont want an animation because we want it to respond immediately to user input. We do this by directly modifying the transform to match the offset for the manipulation, and then well let the animation bring it back to zero when the manipulation completes.  The manipulation events do a great job of keeping track of all the stuff that you usually had to do yourself when doing drags: where you started from, how far youve moved, etc. So we can easily modify the position as below: 1: private void welcome_ManipulationDelta(object sender, ManipulationDeltaEventArgs e) 2: { 3: CompositeTransform transform = (CompositeTransform)welcome.RenderTransform; 4:   5: transform.TranslateX = e.CumulativeManipulation.Translation.X; 6: transform.TranslateY = e.CumulativeManipulation.Translation.Y; 7: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Thats it! Go ahead and run the app in the emulator.  I suggest running without the debugger, its a little faster (CTRL+F5).  If youve got a machine that supports DirectX 10, youll see nice smooth GPU accelerated graphics, which also what it looks like on the phone, running at about 60 frames per second.  If your machine does not support DX10 (like the laptop Im writing this on!), it wont be quite a smooth so youll have to take my word for it! Comparing Against the iPhone This is an example where the flexibility and power of XAML meets the tooling of Visual Studio and Blend, and the whole experience really shines.  So, for several things that are declarative and 100% toolable with the Windows Phone 7 Series, this example does them with code on the iPhone.  In parens is the lines of code that I count to do these operations. PlacardView.m: 19 total LOC Creating the view that hosts the button-like image and the text Drawing the image that is the background of the button Drawing the Welcome text over the image (I think you could technically do this step and/or the prior one using Interface Builder) MoveMeView.m:  63 total LOC Constructing and running the scale (throb) animation (25) Constructing the path describing the animation back to center plus bounce effect (38) Beyond the code count, yy experience with doing this kind of thing in code is that its VERY time intensive.  When I was a developer back on Windows Forms, doing GDI+ drawing, we did this stuff a lot, and it took forever!  You write some code and even once you get it basically working, you see its not quite right, you go back, tweak the interval, or the math a bit, run it again, etc.  You can take a look at the iPhone code here to judge for yourself.  Scroll down to animatePlacardViewToCenter toward the bottom.  I dont think this code is terribly complicated, but its not what Id call simple and its not at all simple to get right. And then theres a few other lines of code running around for setting up the ViewController and the Views, about 15 lines between MoveMeAppDelegate, PlacardView, and MoveMeView, plus the assorted decls in the h files. Adding those up, I conservatively get something like 100 lines of code (19+63+15+decls) on iPhone that I have to write, by hand, to make this project work. The lines of code that I wrote in the examples above is 5 lines of code on Windows Phone 7 Series. In terms of incremental concept counts beyond the HelloWorld app, heres a shot at that: iPhone: Drawing Images Drawing Text Handling touch events Creating animations Scaling animations Building a path and animating along that Windows Phone 7 Series: Laying out UI in Blend Creating & testing basic animations in Blend Handling touch events Invoking animations from code This was actually the first example I tried converting, even before I did the HelloWorld, and I was pretty surprised.  Some of this is luck that this app happens to match up with the Windows Phone 7 Series platform just perfectly.  In terms of time, I wrote the above application, from scratch, in about 10 minutes.  I dont know how long it would take a very skilled iPhone developer to write MoveMe on that iPhone from scratch, but if I was to write it on Silverlight in the same way (e.g. all via code), I think it would likely take me at least an hour or two to get it all working right, maybe more if I ended up picking the wrong strategy or couldnt get the math right, etc. Making Some Tweaks Silverlight contains a feature called Projections to do a variety of 3D-like effects with a 2D surface. So lets play with that a bit. Go back to Blend and select the welcome Border in the object tree.  In its properties, scroll down to the bottom, open Transform, and see Projection at the bottom.  Set X,Y,Z to 90.  Youll see the element kind of disappear, replaced by a thin blue line. Now Create a new animation called startupStoryboard. Set its key time to .5 seconds in the timeline view Set the projection values above to 0 for X, Y, and Z. Save Go back to Visual Studio, and in the constructor, add the following bold code (lines 7-9 to the constructor: 1: public MainPage() 2: { 3: InitializeComponent(); 4:   5: SupportedOrientations = SupportedPageOrientation.Portrait; 6:   7: this.Loaded += (s, e) => 8: { 9: startupStoryboard.Begin(); 10: }; 11: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } If the code above looks funny, its using something called a lambda in C#, which is an inline anonymous method.  Its just a handy shorthand for creating a handler like the manipulation ones above. So with this youll get a nice 3D looking fly in effect when the app starts up.  Here it is, in flight: Pretty cool!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Problem using a public key when connecting to a SSH server running on Cygwin

    - by binary255
    We have installed Cygwin on a Windows Server 2008 Standard server and it working pretty well. Unfortunately we still have a big problem. We want to connect using a public key through SSH which doesn't work. It always falls back to using password login. We have appended our public key to ~/.ssh/authorized_keys on the server and we have our private and public key in ~/.ssh/id_dsa respective ~/.ssh/id_dsa.pub on the client. When debugging the SSH login session we see that the key is offered by the server apparently rejects it by some unknown reason. The SSH output when connecting from an Ubuntu 9.10 desktop with debug information enabled: $ ssh -v 192.168.10.11 OpenSSH_5.1p1 Debian-6ubuntu2, OpenSSL 0.9.8g 19 Oct 2007 debug1: Reading configuration data /home/myuseraccount/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for debug1: Connecting to 192.168.10.11 [192.168.10.11] port 22. debug1: Connection established. debug1: identity file /home/myuseraccount/.ssh/identity type -1 debug1: identity file /home/myuseraccount/.ssh/id_rsa type -1 debug1: identity file /home/myuseraccount/.ssh/id_dsa type 2 debug1: Checking blacklist file /usr/share/ssh/blacklist.DSA-1024 debug1: Checking blacklist file /etc/ssh/blacklist.DSA-1024 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3 debug1: match: OpenSSH_5.3 pat OpenSSH debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-cbc hmac-md5 none debug1: kex: client->server aes128-cbc hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Host '192.168.10.11' is known and matches the RSA host key. debug1: Found key in /home/myuseraccount/.ssh/known_hosts:12 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Next authentication method: publickey debug1: Offering public key: /home/myuseraccount/.ssh/id_dsa debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Trying private key: /home/myuseraccount/.ssh/identity debug1: Trying private key: /home/myuseraccount/.ssh/id_rsa debug1: Next authentication method: keyboard-interactive debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Next authentication method: password [email protected]'s password: The version of Cygwin: $ uname -a CYGWIN_NT-6.0 servername 1.7.1(0.218/5/3) 2009-12-07 11:48 i686 Cygwin The installed packages: $ cygcheck -c Cygwin Package Information Package Version Status _update-info-dir 00871-1 OK alternatives 1.3.30c-10 OK arj 3.10.22-1 OK aspell 0.60.5-1 OK aspell-en 6.0.0-1 OK aspell-sv 0.50.2-2 OK autossh 1.4b-1 OK base-cygwin 2.1-1 OK base-files 3.9-3 OK base-passwd 3.1-1 OK bash 3.2.49-23 OK bash-completion 1.1-2 OK bc 1.06-2 OK bzip2 1.0.5-10 OK cabextract 1.1-1 OK compface 1.5.2-1 OK coreutils 7.0-2 OK cron 4.1-59 OK crypt 1.1-1 OK csih 0.9.1-1 OK curl 7.19.6-1 OK cvs 1.12.13-10 OK cvsutils 0.2.5-1 OK cygrunsrv 1.34-1 OK cygutils 1.4.2-1 OK cygwin 1.7.1-1 OK cygwin-doc 1.5-1 OK cygwin-x-doc 1.1.0-1 OK dash 0.5.5.1-2 OK diffutils 2.8.7-2 OK doxygen 1.6.1-2 OK e2fsprogs 1.35-3 OK editrights 1.01-2 OK emacs 23.1-10 OK emacs-X11 23.1-10 OK file 5.04-1 OK findutils 4.5.5-1 OK flip 1.19-1 OK font-adobe-dpi75 1.0.1-1 OK font-alias 1.0.2-1 OK font-encodings 1.0.3-1 OK font-misc-misc 1.1.0-1 OK fontconfig 2.8.0-1 OK gamin 0.1.10-10 OK gawk 3.1.7-1 OK gettext 0.17-11 OK gnome-icon-theme 2.28.0-1 OK grep 2.5.4-2 OK groff 1.19.2-2 OK gvim 7.2.264-1 OK gzip 1.3.12-2 OK hicolor-icon-theme 0.11-1 OK inetutils 1.5-6 OK ipc-utils 1.0-1 OK keychain 2.6.8-1 OK less 429-1 OK libaspell15 0.60.5-1 OK libatk1.0_0 1.28.0-1 OK libaudio2 1.9.2-1 OK libbz2_1 1.0.5-10 OK libcairo2 1.8.8-1 OK libcurl4 7.19.6-1 OK libdb4.2 4.2.52.5-2 OK libdb4.5 4.5.20.2-2 OK libexpat1 2.0.1-1 OK libfam0 0.1.10-10 OK libfontconfig1 2.8.0-1 OK libfontenc1 1.0.5-1 OK libfreetype6 2.3.12-1 OK libgcc1 4.3.4-3 OK libgdbm4 1.8.3-20 OK libgdk_pixbuf2.0_0 2.18.6-1 OK libgif4 4.1.6-10 OK libGL1 7.6.1-1 OK libglib2.0_0 2.22.4-2 OK libglitz1 0.5.6-10 OK libgmp3 4.3.1-3 OK libgtk2.0_0 2.18.6-1 OK libICE6 1.0.6-1 OK libiconv2 1.13.1-1 OK libidn11 1.16-1 OK libintl3 0.14.5-1 OK libintl8 0.17-11 OK libjasper1 1.900.1-1 OK libjbig2 2.0-11 OK libjpeg62 6b-21 OK libjpeg7 7-10 OK liblzma1 4.999.9beta-10 OK libncurses10 5.7-18 OK libncurses8 5.5-10 OK libncurses9 5.7-16 OK libopenldap2_3_0 2.3.43-1 OK libpango1.0_0 1.26.2-1 OK libpcre0 8.00-1 OK libpixman1_0 0.16.6-1 OK libpng12 1.2.35-10 OK libpopt0 1.6.4-4 OK libpq5 8.2.11-1 OK libreadline6 5.2.14-12 OK libreadline7 6.0.3-2 OK libsasl2 2.1.19-3 OK libSM6 1.1.1-1 OK libssh2_1 1.2.2-1 OK libssp0 4.3.4-3 OK libstdc++6 4.3.4-3 OK libtiff5 3.9.2-1 OK libwrap0 7.6-20 OK libX11_6 1.3.3-1 OK libXau6 1.0.5-1 OK libXaw3d7 1.5D-8 OK libXaw7 1.0.7-1 OK libxcb-render-util0 0.3.6-1 OK libxcb-render0 1.5-1 OK libxcb1 1.5-1 OK libXcomposite1 0.4.1-1 OK libXcursor1 1.1.10-1 OK libXdamage1 1.1.2-1 OK libXdmcp6 1.0.3-1 OK libXext6 1.1.1-1 OK libXfixes3 4.0.4-1 OK libXft2 2.1.14-1 OK libXi6 1.3-1 OK libXinerama1 1.1-1 OK libxkbfile1 1.0.6-1 OK libxml2 2.7.6-1 OK libXmu6 1.0.5-1 OK libXmuu1 1.0.5-1 OK libXpm4 3.5.8-1 OK libXrandr2 1.3.0-10 OK libXrender1 0.9.5-1 OK libXt6 1.0.7-1 OK links 1.00pre20-1 OK login 1.10-10 OK luit 1.0.5-1 OK lynx 2.8.5-4 OK man 1.6e-1 OK minires 1.02-1 OK mkfontdir 1.0.5-1 OK mkfontscale 1.0.7-1 OK openssh 5.4p1-1 OK openssl 0.9.8m-1 OK patch 2.5.8-9 OK patchutils 0.3.1-1 OK perl 5.10.1-3 OK rebase 3.0.1-1 OK run 1.1.12-11 OK screen 4.0.3-5 OK sed 4.1.5-2 OK shared-mime-info 0.70-1 OK tar 1.22.90-1 OK terminfo 5.7_20091114-13 OK terminfo0 5.5_20061104-11 OK texinfo 4.13-3 OK tidy 041206-1 OK time 1.7-2 OK tzcode 2009k-1 OK unzip 6.0-10 OK util-linux 2.14.1-1 OK vim 7.2.264-2 OK wget 1.11.4-4 OK which 2.20-2 OK wput 0.6.1-2 OK xauth 1.0.4-1 OK xclipboard 1.1.0-1 OK xcursor-themes 1.0.2-1 OK xemacs 21.4.22-1 OK xemacs-emacs-common 21.4.22-1 OK xemacs-sumo 2007-04-27-1 OK xemacs-tags 21.4.22-1 OK xeyes 1.1.0-1 OK xinit 1.2.1-1 OK xinput 1.5.0-1 OK xkbcomp 1.1.1-1 OK xkeyboard-config 1.8-1 OK xkill 1.0.2-1 OK xmodmap 1.0.4-1 OK xorg-docs 1.5-1 OK xorg-server 1.7.6-2 OK xrdb 1.0.6-1 OK xset 1.1.0-1 OK xterm 255-1 OK xz 4.999.9beta-10 OK zip 3.0-11 OK zlib 1.2.3-10 OK zlib-devel 1.2.3-10 OK zlib0 1.2.3-10 OK The ssh deamon configuration file: $ cat /etc/sshd_config # $OpenBSD: sshd_config,v 1.80 2008/07/02 02:24:18 djm Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/bin:/usr/sbin:/sbin:/usr/bin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options change a # default value. Port 22 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: # Disable legacy (protocol version 1) support in the server for new # installations. In future the default will change to require explicit # activation of protocol 1 Protocol 2 # HostKey for protocol version 1 #HostKey /etc/ssh_host_key # HostKeys for protocol version 2 #HostKey /etc/ssh_host_rsa_key #HostKey /etc/ssh_host_dsa_key # Lifetime and size of ephemeral version 1 server key #KeyRegenerationInterval 1h #ServerKeyBits 1024 # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH #LogLevel INFO # Authentication: #LoginGraceTime 2m #PermitRootLogin yes StrictModes no #MaxAuthTries 6 #MaxSessions 10 RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile .ssh/authorized_keys # For this to work you will also need host keys in /etc/ssh_known_hosts #RhostsRSAAuthentication no # similar for protocol version 2 #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # RhostsRSAAuthentication and HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # To disable tunneled clear text passwords, change to no here! #PasswordAuthentication yes #PermitEmptyPasswords no # Change to no to disable s/key passwords #ChallengeResponseAuthentication yes # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. #UsePAM no AllowAgentForwarding yes AllowTcpForwarding yes GatewayPorts yes X11Forwarding yes X11DisplayOffset 10 X11UseLocalhost no #PrintMotd yes #PrintLastLog yes TCPKeepAlive yes #UseLogin no UsePrivilegeSeparation yes #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #UseDNS yes #PidFile /var/run/sshd.pid #MaxStartups 10 #PermitTunnel no #ChrootDirectory none # no default banner path #Banner none # override default of no subsystems Subsystem sftp /usr/sbin/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs #X11Forwarding yes #AllowTcpForwarding yes #ForceCommand cvs server I hope this information is enough to solve the problem. In case any more is needed please comment and I'll add it. Thank you for reading!

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  • Problem using a public key when connecting to a SSH server running on Cygwin

    - by Deleted
    We have installed Cygwin on a Windows Server 2008 Standard server and it working pretty well. Unfortunately we still have a big problem. We want to connect using a public key through SSH which doesn't work. It always falls back to using password login. We have appended our public key to ~/.ssh/authorized_keys on the server and we have our private and public key in ~/.ssh/id_dsa respective ~/.ssh/id_dsa.pub on the client. When debugging the SSH login session we see that the key is offered by the server apparently rejects it by some unknown reason. The SSH output when connecting from an Ubuntu 9.10 desktop with debug information enabled: $ ssh -v 192.168.10.11 OpenSSH_5.1p1 Debian-6ubuntu2, OpenSSL 0.9.8g 19 Oct 2007 debug1: Reading configuration data /home/myuseraccount/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for debug1: Connecting to 192.168.10.11 [192.168.10.11] port 22. debug1: Connection established. debug1: identity file /home/myuseraccount/.ssh/identity type -1 debug1: identity file /home/myuseraccount/.ssh/id_rsa type -1 debug1: identity file /home/myuseraccount/.ssh/id_dsa type 2 debug1: Checking blacklist file /usr/share/ssh/blacklist.DSA-1024 debug1: Checking blacklist file /etc/ssh/blacklist.DSA-1024 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3 debug1: match: OpenSSH_5.3 pat OpenSSH debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-cbc hmac-md5 none debug1: kex: client->server aes128-cbc hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Host '192.168.10.11' is known and matches the RSA host key. debug1: Found key in /home/myuseraccount/.ssh/known_hosts:12 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Next authentication method: publickey debug1: Offering public key: /home/myuseraccount/.ssh/id_dsa debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Trying private key: /home/myuseraccount/.ssh/identity debug1: Trying private key: /home/myuseraccount/.ssh/id_rsa debug1: Next authentication method: keyboard-interactive debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Next authentication method: password [email protected]'s password: The version of Cygwin: $ uname -a CYGWIN_NT-6.0 servername 1.7.1(0.218/5/3) 2009-12-07 11:48 i686 Cygwin The installed packages: $ cygcheck -c Cygwin Package Information Package Version Status _update-info-dir 00871-1 OK alternatives 1.3.30c-10 OK arj 3.10.22-1 OK aspell 0.60.5-1 OK aspell-en 6.0.0-1 OK aspell-sv 0.50.2-2 OK autossh 1.4b-1 OK base-cygwin 2.1-1 OK base-files 3.9-3 OK base-passwd 3.1-1 OK bash 3.2.49-23 OK bash-completion 1.1-2 OK bc 1.06-2 OK bzip2 1.0.5-10 OK cabextract 1.1-1 OK compface 1.5.2-1 OK coreutils 7.0-2 OK cron 4.1-59 OK crypt 1.1-1 OK csih 0.9.1-1 OK curl 7.19.6-1 OK cvs 1.12.13-10 OK cvsutils 0.2.5-1 OK cygrunsrv 1.34-1 OK cygutils 1.4.2-1 OK cygwin 1.7.1-1 OK cygwin-doc 1.5-1 OK cygwin-x-doc 1.1.0-1 OK dash 0.5.5.1-2 OK diffutils 2.8.7-2 OK doxygen 1.6.1-2 OK e2fsprogs 1.35-3 OK editrights 1.01-2 OK emacs 23.1-10 OK emacs-X11 23.1-10 OK file 5.04-1 OK findutils 4.5.5-1 OK flip 1.19-1 OK font-adobe-dpi75 1.0.1-1 OK font-alias 1.0.2-1 OK font-encodings 1.0.3-1 OK font-misc-misc 1.1.0-1 OK fontconfig 2.8.0-1 OK gamin 0.1.10-10 OK gawk 3.1.7-1 OK gettext 0.17-11 OK gnome-icon-theme 2.28.0-1 OK grep 2.5.4-2 OK groff 1.19.2-2 OK gvim 7.2.264-1 OK gzip 1.3.12-2 OK hicolor-icon-theme 0.11-1 OK inetutils 1.5-6 OK ipc-utils 1.0-1 OK keychain 2.6.8-1 OK less 429-1 OK libaspell15 0.60.5-1 OK libatk1.0_0 1.28.0-1 OK libaudio2 1.9.2-1 OK libbz2_1 1.0.5-10 OK libcairo2 1.8.8-1 OK libcurl4 7.19.6-1 OK libdb4.2 4.2.52.5-2 OK libdb4.5 4.5.20.2-2 OK libexpat1 2.0.1-1 OK libfam0 0.1.10-10 OK libfontconfig1 2.8.0-1 OK libfontenc1 1.0.5-1 OK libfreetype6 2.3.12-1 OK libgcc1 4.3.4-3 OK libgdbm4 1.8.3-20 OK libgdk_pixbuf2.0_0 2.18.6-1 OK libgif4 4.1.6-10 OK libGL1 7.6.1-1 OK libglib2.0_0 2.22.4-2 OK libglitz1 0.5.6-10 OK libgmp3 4.3.1-3 OK libgtk2.0_0 2.18.6-1 OK libICE6 1.0.6-1 OK libiconv2 1.13.1-1 OK libidn11 1.16-1 OK libintl3 0.14.5-1 OK libintl8 0.17-11 OK libjasper1 1.900.1-1 OK libjbig2 2.0-11 OK libjpeg62 6b-21 OK libjpeg7 7-10 OK liblzma1 4.999.9beta-10 OK libncurses10 5.7-18 OK libncurses8 5.5-10 OK libncurses9 5.7-16 OK libopenldap2_3_0 2.3.43-1 OK libpango1.0_0 1.26.2-1 OK libpcre0 8.00-1 OK libpixman1_0 0.16.6-1 OK libpng12 1.2.35-10 OK libpopt0 1.6.4-4 OK libpq5 8.2.11-1 OK libreadline6 5.2.14-12 OK libreadline7 6.0.3-2 OK libsasl2 2.1.19-3 OK libSM6 1.1.1-1 OK libssh2_1 1.2.2-1 OK libssp0 4.3.4-3 OK libstdc++6 4.3.4-3 OK libtiff5 3.9.2-1 OK libwrap0 7.6-20 OK libX11_6 1.3.3-1 OK libXau6 1.0.5-1 OK libXaw3d7 1.5D-8 OK libXaw7 1.0.7-1 OK libxcb-render-util0 0.3.6-1 OK libxcb-render0 1.5-1 OK libxcb1 1.5-1 OK libXcomposite1 0.4.1-1 OK libXcursor1 1.1.10-1 OK libXdamage1 1.1.2-1 OK libXdmcp6 1.0.3-1 OK libXext6 1.1.1-1 OK libXfixes3 4.0.4-1 OK libXft2 2.1.14-1 OK libXi6 1.3-1 OK libXinerama1 1.1-1 OK libxkbfile1 1.0.6-1 OK libxml2 2.7.6-1 OK libXmu6 1.0.5-1 OK libXmuu1 1.0.5-1 OK libXpm4 3.5.8-1 OK libXrandr2 1.3.0-10 OK libXrender1 0.9.5-1 OK libXt6 1.0.7-1 OK links 1.00pre20-1 OK login 1.10-10 OK luit 1.0.5-1 OK lynx 2.8.5-4 OK man 1.6e-1 OK minires 1.02-1 OK mkfontdir 1.0.5-1 OK mkfontscale 1.0.7-1 OK openssh 5.4p1-1 OK openssl 0.9.8m-1 OK patch 2.5.8-9 OK patchutils 0.3.1-1 OK perl 5.10.1-3 OK rebase 3.0.1-1 OK run 1.1.12-11 OK screen 4.0.3-5 OK sed 4.1.5-2 OK shared-mime-info 0.70-1 OK tar 1.22.90-1 OK terminfo 5.7_20091114-13 OK terminfo0 5.5_20061104-11 OK texinfo 4.13-3 OK tidy 041206-1 OK time 1.7-2 OK tzcode 2009k-1 OK unzip 6.0-10 OK util-linux 2.14.1-1 OK vim 7.2.264-2 OK wget 1.11.4-4 OK which 2.20-2 OK wput 0.6.1-2 OK xauth 1.0.4-1 OK xclipboard 1.1.0-1 OK xcursor-themes 1.0.2-1 OK xemacs 21.4.22-1 OK xemacs-emacs-common 21.4.22-1 OK xemacs-sumo 2007-04-27-1 OK xemacs-tags 21.4.22-1 OK xeyes 1.1.0-1 OK xinit 1.2.1-1 OK xinput 1.5.0-1 OK xkbcomp 1.1.1-1 OK xkeyboard-config 1.8-1 OK xkill 1.0.2-1 OK xmodmap 1.0.4-1 OK xorg-docs 1.5-1 OK xorg-server 1.7.6-2 OK xrdb 1.0.6-1 OK xset 1.1.0-1 OK xterm 255-1 OK xz 4.999.9beta-10 OK zip 3.0-11 OK zlib 1.2.3-10 OK zlib-devel 1.2.3-10 OK zlib0 1.2.3-10 OK The ssh deamon configuration file: $ cat /etc/sshd_config # $OpenBSD: sshd_config,v 1.80 2008/07/02 02:24:18 djm Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/bin:/usr/sbin:/sbin:/usr/bin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options change a # default value. Port 22 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: # Disable legacy (protocol version 1) support in the server for new # installations. In future the default will change to require explicit # activation of protocol 1 Protocol 2 # HostKey for protocol version 1 #HostKey /etc/ssh_host_key # HostKeys for protocol version 2 #HostKey /etc/ssh_host_rsa_key #HostKey /etc/ssh_host_dsa_key # Lifetime and size of ephemeral version 1 server key #KeyRegenerationInterval 1h #ServerKeyBits 1024 # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH #LogLevel INFO # Authentication: #LoginGraceTime 2m #PermitRootLogin yes StrictModes no #MaxAuthTries 6 #MaxSessions 10 RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile .ssh/authorized_keys # For this to work you will also need host keys in /etc/ssh_known_hosts #RhostsRSAAuthentication no # similar for protocol version 2 #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # RhostsRSAAuthentication and HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # To disable tunneled clear text passwords, change to no here! #PasswordAuthentication yes #PermitEmptyPasswords no # Change to no to disable s/key passwords #ChallengeResponseAuthentication yes # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. #UsePAM no AllowAgentForwarding yes AllowTcpForwarding yes GatewayPorts yes X11Forwarding yes X11DisplayOffset 10 X11UseLocalhost no #PrintMotd yes #PrintLastLog yes TCPKeepAlive yes #UseLogin no UsePrivilegeSeparation yes #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #UseDNS yes #PidFile /var/run/sshd.pid #MaxStartups 10 #PermitTunnel no #ChrootDirectory none # no default banner path #Banner none # override default of no subsystems Subsystem sftp /usr/sbin/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs #X11Forwarding yes #AllowTcpForwarding yes #ForceCommand cvs server I hope this information is enough to solve the problem. In case any more is needed please comment and I'll add it. Thank you for reading!

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  • Red Gate Coder interviews: Alex Davies

    - by Michael Williamson
    Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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  • actionscript3: reflect-class applied on rotationY

    - by algro
    Hi, I'm using a class which applies a visual reflection-effect to defined movieclips. I use a reflection-class from here: link to source. It works like a charm except when I apply a rotation to the movieclip. In my case the reflection is still visible but only a part of it. What am I doing wrong? How could I pass/include the rotation to the Reflection-Class ? Thanks in advance! This is how you apply the Reflection Class to your movieclip: var ref_mc:MovieClip = new MoviClip(); addChild(ref_mc); var r1:Reflect = new Reflect({mc:ref_mc, alpha:50, ratio:50,distance:0, updateTime:0,reflectionDropoff:1}); Now I apply a rotation to my movieclip: ref_mc.rotationY = 30; And Here the Reflect-Class: package com.pixelfumes.reflect{ import flash.display.MovieClip; import flash.display.DisplayObject; import flash.display.BitmapData; import flash.display.Bitmap; import flash.geom.Matrix; import flash.display.GradientType; import flash.display.SpreadMethod; import flash.utils.setInterval; import flash.utils.clearInterval; public class Reflect extends MovieClip{ //Created By Ben Pritchard of Pixelfumes 2007 //Thanks to Mim, Jasper, Jason Merrill and all the others who //have contributed to the improvement of this class //static var for the version of this class private static var VERSION:String = "4.0"; //reference to the movie clip we are reflecting private var mc:MovieClip; //the BitmapData object that will hold a visual copy of the mc private var mcBMP:BitmapData; //the BitmapData object that will hold the reflected image private var reflectionBMP:Bitmap; //the clip that will act as out gradient mask private var gradientMask_mc:MovieClip; //how often the reflection should update (if it is video or animated) private var updateInt:Number; //the size the reflection is allowed to reflect within private var bounds:Object; //the distance the reflection is vertically from the mc private var distance:Number = 0; function Reflect(args:Object){ /*the args object passes in the following variables /we set the values of our internal vars to math the args*/ //the clip being reflected mc = args.mc; //the alpha level of the reflection clip var alpha:Number = args.alpha/100; //the ratio opaque color used in the gradient mask var ratio:Number = args.ratio; //update time interval var updateTime:Number = args.updateTime; //the distance at which the reflection visually drops off at var reflectionDropoff:Number = args.reflectionDropoff; //the distance the reflection starts from the bottom of the mc var distance:Number = args.distance; //store width and height of the clip var mcHeight = mc.height; var mcWidth = mc.width; //store the bounds of the reflection bounds = new Object(); bounds.width = mcWidth; bounds.height = mcHeight; //create the BitmapData that will hold a snapshot of the movie clip mcBMP = new BitmapData(bounds.width, bounds.height, true, 0xFFFFFF); mcBMP.draw(mc); //create the BitmapData the will hold the reflection reflectionBMP = new Bitmap(mcBMP); //flip the reflection upside down reflectionBMP.scaleY = -1; //move the reflection to the bottom of the movie clip reflectionBMP.y = (bounds.height*2) + distance; //add the reflection to the movie clip's Display Stack var reflectionBMPRef:DisplayObject = mc.addChild(reflectionBMP); reflectionBMPRef.name = "reflectionBMP"; //add a blank movie clip to hold our gradient mask var gradientMaskRef:DisplayObject = mc.addChild(new MovieClip()); gradientMaskRef.name = "gradientMask_mc"; //get a reference to the movie clip - cast the DisplayObject that is returned as a MovieClip gradientMask_mc = mc.getChildByName("gradientMask_mc") as MovieClip; //set the values for the gradient fill var fillType:String = GradientType.LINEAR; var colors:Array = [0xFFFFFF, 0xFFFFFF]; var alphas:Array = [alpha, 0]; var ratios:Array = [0, ratio]; var spreadMethod:String = SpreadMethod.PAD; //create the Matrix and create the gradient box var matr:Matrix = new Matrix(); //set the height of the Matrix used for the gradient mask var matrixHeight:Number; if (reflectionDropoff<=0) { matrixHeight = bounds.height; } else { matrixHeight = bounds.height/reflectionDropoff; } matr.createGradientBox(bounds.width, matrixHeight, (90/180)*Math.PI, 0, 0); //create the gradient fill gradientMask_mc.graphics.beginGradientFill(fillType, colors, alphas, ratios, matr, spreadMethod); gradientMask_mc.graphics.drawRect(0,0,bounds.width,bounds.height); //position the mask over the reflection clip gradientMask_mc.y = mc.getChildByName("reflectionBMP").y - mc.getChildByName("reflectionBMP").height; //cache clip as a bitmap so that the gradient mask will function gradientMask_mc.cacheAsBitmap = true; mc.getChildByName("reflectionBMP").cacheAsBitmap = true; //set the mask for the reflection as the gradient mask mc.getChildByName("reflectionBMP").mask = gradientMask_mc; //if we are updating the reflection for a video or animation do so here if(updateTime > -1){ updateInt = setInterval(update, updateTime, mc); } } public function setBounds(w:Number,h:Number):void{ //allows the user to set the area that the reflection is allowed //this is useful for clips that move within themselves bounds.width = w; bounds.height = h; gradientMask_mc.width = bounds.width; redrawBMP(mc); } public function redrawBMP(mc:MovieClip):void { // redraws the bitmap reflection - Mim Gamiet [2006] mcBMP.dispose(); mcBMP = new BitmapData(bounds.width, bounds.height, true, 0xFFFFFF); mcBMP.draw(mc); } private function update(mc):void { //updates the reflection to visually match the movie clip mcBMP = new BitmapData(bounds.width, bounds.height, true, 0xFFFFFF); mcBMP.draw(mc); reflectionBMP.bitmapData = mcBMP; } public function destroy():void{ //provides a method to remove the reflection mc.removeChild(mc.getChildByName("reflectionBMP")); reflectionBMP = null; mcBMP.dispose(); clearInterval(updateInt); mc.removeChild(mc.getChildByName("gradientMask_mc")); } } }

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  • SocketChannel in Java sends data, but it doesn't get to destination application

    - by Peterson
    Hi Everybody, I'm suffering a lot to create a simple ChatServer in Java, using the NIO libraries. Wonder if someone could help me. I am doing that by using SocketChannel and Selector to handle multiple clients in a single thread. The problem is: I am able to accept new connections and get it's data, but when I try to send data back, the SocketChannel simply doesn't work. In the method write(), it returns a integer that is the same size of the data i'm passing to it, but the client never receives that data. Strangely, when I close the server application, the client receives the data. It's like the socketchannel maintains a buffer, and it only get flushed when I close the application. Here are some more details, to give you more information to help. I'm handling the events in this piece of code: private void run() throws IOException { ServerSocketChannel ssc = ServerSocketChannel.open(); // Set it to non-blocking, so we can use select ssc.configureBlocking( false ); // Get the Socket connected to this channel, and bind it // to the listening port this.serverSocket = ssc.socket(); InetSocketAddress isa = new InetSocketAddress( this.port ); serverSocket.bind( isa ); // Create a new Selector for selecting this.masterSelector = Selector.open(); // Register the ServerSocketChannel, so we can // listen for incoming connections ssc.register( masterSelector, SelectionKey.OP_ACCEPT ); while (true) { // See if we've had any activity -- either // an incoming connection, or incoming data on an // existing connection int num = masterSelector.select(); // If we don't have any activity, loop around and wait // again if (num == 0) { continue; } // Get the keys corresponding to the activity // that has been detected, and process them // one by one Set keys = masterSelector.selectedKeys(); Iterator it = keys.iterator(); while (it.hasNext()) { // Get a key representing one of bits of I/O // activity SelectionKey key = (SelectionKey)it.next(); // What kind of activity is it? if ((key.readyOps() & SelectionKey.OP_ACCEPT) == SelectionKey.OP_ACCEPT) { // Aceita a conexão Socket s = serverSocket.accept(); System.out.println( "LOG: Conexao TCP aceita de " + s.getInetAddress() + ":" + s.getPort() ); // Make sure to make it non-blocking, so we can // use a selector on it. SocketChannel sc = s.getChannel(); sc.configureBlocking( false ); // Registra a conexao no seletor, apenas para leitura sc.register( masterSelector, SelectionKey.OP_READ ); } else if ( key.isReadable() ) { SocketChannel sc = null; // It's incoming data on a connection, so // process it sc = (SocketChannel)key.channel(); // Verifica se a conexão corresponde a um cliente já existente if((clientsMap.getClient(key)) != null){ boolean closedConnection = !processIncomingClientData(key); if(closedConnection){ int id = clientsMap.getClient(key); closeClient(id); } } else { boolean clientAccepted = processIncomingDataFromNewClient(key); if(!clientAccepted){ // Se o cliente não foi aceito, sua conexão é simplesmente fechada sc.socket().close(); sc.close(); key.cancel(); } } } } // We remove the selected keys, because we've dealt // with them. keys.clear(); } } This piece of code is simply handles new clients that wants to connect to the chat. So, a client makes a TCP connection to the server, and once it gets accepted, it sends data to the server following a simply text protocol, informing his id and asking to get registrated to the server. I handle this in the method processIncomingDataFromNewClient(key). I'm also keeping a map of clients and its connections in a data structure similar to a hashtable. I? doing that because I need to recover a client Id from a connection and a connection from a client Id. This is can be shown in: clientsMap.getClient(key). But the problem itself resides in the method processIncomingDataFromNewClient(key). There, I simply read the data that the client sent to me, validate it, and if it's ok, I send a message back to the client to tell that it is connected to the chat server. Here is a similar piece of code: private boolean processIncomingDataFromNewClient(SelectionKey key){ SocketChannel sc = (SocketChannel) key.channel(); String connectionOrigin = sc.socket().getInetAddress() + ":" + sc.socket().getPort(); int id = 0; //id of the client buf.clear(); int bytesRead = 0; try { bytesRead = sc.read(buf); if(bytesRead<=0){ System.out.println("Conexão fechada pelo: " + connectionOrigin); return false; } System.out.println("LOG: " + bytesRead + " bytes lidos de " + connectionOrigin); String msg = new String(buf.array(),0,bytesRead); // Do validations with the client sent me here // gets the client id }catch (Exception e) { e.printStackTrace(); System.out.println("LOG: Oops. Cliente não conhece o protocolo. Fechando a conexão: " + connectionOrigin); System.out.println("LOG: Primeiros 10 caracteres enviados pelo cliente: " + msg); return false; } } } catch (IOException e) { System.out.println("LOG: Erro ao ler dados da conexao: " + connectionOrigin); System.out.println("LOG: "+ e.getLocalizedMessage()); System.out.println("LOG: Fechando a conexão..."); return false; } // If it gets to here, the protocol is ok and we can add the client boolean inserted = clientsMap.addClient(key, id); if(!inserted){ System.out.println("LOG: Não foi possível adicionar o cliente. Ou ele já está conectado ou já têm clientes demais. Id: " + id); System.out.println("LOG: Fechando a conexão: " + connectionOrigin); return false; } System.out.println("LOG: Novo cliente conectado! Enviando mesnsagem de confirmação. Id: " + id + " Conexao: " + connectionOrigin); /* Here is the error */ sendMessage(id, "Servidor pet: connection accepted"); System.out.println("LOG: Novo cliente conectado! Id: " + id + " Conexao: " + connectionOrigin); return true; } And finally, the method sendMessage(SelectionKey key) looks like this: private void sendMessage(int destId, String msg) { Charset charset = Charset.forName("ISO-8859-1"); CharBuffer charBuffer = CharBuffer.wrap(msg, 0, msg.length()); ByteBuffer bf = charset.encode(charBuffer); //bf.flip(); int bytesSent = 0; SelectionKey key = clientsMap.getClient(destId); SocketChannel sc = (SocketChannel) key.channel(); try { / int total_bytes_sent = 0; while(total_bytes_sent < msg.length()){ bytesSent = sc.write(bf); total_bytes_sent += bytesSent; } System.out.println("LOG: Bytes enviados para o cliente " + destId + ": "+ total_bytes_sent + " Tamanho da mensagem: " + msg.length()); } catch (IOException e) { System.out.println("LOG: Erro ao mandar mensagem para: " + destId); System.out.println("LOG: " + e.getLocalizedMessage()); } } So, what is happening is that the server, when send a message, prints something like this: LOG: Bytes sent to the client: 28 Size of the message: 28 So, it tells that it sent the data, but the chat client keeps blocking, waiting in the recv() method. So, the data never gets to it. When I close the server application, though, all the data appears in the client. I wonder why. It is important to say that the client is in C and the server JAVA, and I'm running both in the same machine, an Ubuntu Guest in virtualbox under windows. I also run both under windows host and under linuxes hosts, and keep getting the same strange problem. I'm sorry for the great lenght of this question, but I already searched a lot of places for an answer, found a lot of tutorials and questions, including here at StackOverflow, but coundn't find a reasonable explanation. I am really not liking this Java NIO, and i saw a lot of people complaining about it too. I am thinking that if I had done that in C it would have been a lot easier :-D So, if someone could help me and even discuss this behavor, it would be great! :-) Thanks everybody in advance, Péterson

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  • Traditional IO vs memory-mapped

    - by Senne
    I'm trying to illustrate the difference in performance between traditional IO and memory mapped files in java to students. I found an example somewhere on internet but not everything is clear to me, I don't even think all steps are nececery. I read a lot about it here and there but I'm not convinced about a correct implementation of neither of them. The code I try to understand is: public class FileCopy{ public static void main(String args[]){ if (args.length < 1){ System.out.println(" Wrong usage!"); System.out.println(" Correct usage is : java FileCopy <large file with full path>"); System.exit(0); } String inFileName = args[0]; File inFile = new File(inFileName); if (inFile.exists() != true){ System.out.println(inFileName + " does not exist!"); System.exit(0); } try{ new FileCopy().memoryMappedCopy(inFileName, inFileName+".new" ); new FileCopy().customBufferedCopy(inFileName, inFileName+".new1"); }catch(FileNotFoundException fne){ fne.printStackTrace(); }catch(IOException ioe){ ioe.printStackTrace(); }catch (Exception e){ e.printStackTrace(); } } public void memoryMappedCopy(String fromFile, String toFile ) throws Exception{ long timeIn = new Date().getTime(); // read input file RandomAccessFile rafIn = new RandomAccessFile(fromFile, "rw"); FileChannel fcIn = rafIn.getChannel(); ByteBuffer byteBuffIn = fcIn.map(FileChannel.MapMode.READ_WRITE, 0,(int) fcIn.size()); fcIn.read(byteBuffIn); byteBuffIn.flip(); RandomAccessFile rafOut = new RandomAccessFile(toFile, "rw"); FileChannel fcOut = rafOut.getChannel(); ByteBuffer writeMap = fcOut.map(FileChannel.MapMode.READ_WRITE,0,(int) fcIn.size()); writeMap.put(byteBuffIn); long timeOut = new Date().getTime(); System.out.println("Memory mapped copy Time for a file of size :" + (int) fcIn.size() +" is "+(timeOut-timeIn)); fcOut.close(); fcIn.close(); } static final int CHUNK_SIZE = 100000; static final char[] inChars = new char[CHUNK_SIZE]; public static void customBufferedCopy(String fromFile, String toFile) throws IOException{ long timeIn = new Date().getTime(); Reader in = new FileReader(fromFile); Writer out = new FileWriter(toFile); while (true) { synchronized (inChars) { int amountRead = in.read(inChars); if (amountRead == -1) { break; } out.write(inChars, 0, amountRead); } } long timeOut = new Date().getTime(); System.out.println("Custom buffered copy Time for a file of size :" + (int) new File(fromFile).length() +" is "+(timeOut-timeIn)); in.close(); out.close(); } } When exactly is it nececary to use RandomAccessFile? Here it is used to read and write in the memoryMappedCopy, is it actually nececary just to copy a file at all? Or is it a part of memorry mapping? In customBufferedCopy, why is synchronized used here? I also found a different example that -should- test the performance between the 2: public class MappedIO { private static int numOfInts = 4000000; private static int numOfUbuffInts = 200000; private abstract static class Tester { private String name; public Tester(String name) { this.name = name; } public long runTest() { System.out.print(name + ": "); try { long startTime = System.currentTimeMillis(); test(); long endTime = System.currentTimeMillis(); return (endTime - startTime); } catch (IOException e) { throw new RuntimeException(e); } } public abstract void test() throws IOException; } private static Tester[] tests = { new Tester("Stream Write") { public void test() throws IOException { DataOutputStream dos = new DataOutputStream( new BufferedOutputStream( new FileOutputStream(new File("temp.tmp")))); for(int i = 0; i < numOfInts; i++) dos.writeInt(i); dos.close(); } }, new Tester("Mapped Write") { public void test() throws IOException { FileChannel fc = new RandomAccessFile("temp.tmp", "rw") .getChannel(); IntBuffer ib = fc.map( FileChannel.MapMode.READ_WRITE, 0, fc.size()) .asIntBuffer(); for(int i = 0; i < numOfInts; i++) ib.put(i); fc.close(); } }, new Tester("Stream Read") { public void test() throws IOException { DataInputStream dis = new DataInputStream( new BufferedInputStream( new FileInputStream("temp.tmp"))); for(int i = 0; i < numOfInts; i++) dis.readInt(); dis.close(); } }, new Tester("Mapped Read") { public void test() throws IOException { FileChannel fc = new FileInputStream( new File("temp.tmp")).getChannel(); IntBuffer ib = fc.map( FileChannel.MapMode.READ_ONLY, 0, fc.size()) .asIntBuffer(); while(ib.hasRemaining()) ib.get(); fc.close(); } }, new Tester("Stream Read/Write") { public void test() throws IOException { RandomAccessFile raf = new RandomAccessFile( new File("temp.tmp"), "rw"); raf.writeInt(1); for(int i = 0; i < numOfUbuffInts; i++) { raf.seek(raf.length() - 4); raf.writeInt(raf.readInt()); } raf.close(); } }, new Tester("Mapped Read/Write") { public void test() throws IOException { FileChannel fc = new RandomAccessFile( new File("temp.tmp"), "rw").getChannel(); IntBuffer ib = fc.map( FileChannel.MapMode.READ_WRITE, 0, fc.size()) .asIntBuffer(); ib.put(0); for(int i = 1; i < numOfUbuffInts; i++) ib.put(ib.get(i - 1)); fc.close(); } } }; public static void main(String[] args) { for(int i = 0; i < tests.length; i++) System.out.println(tests[i].runTest()); } } I more or less see whats going on, my output looks like this: Stream Write: 653 Mapped Write: 51 Stream Read: 651 Mapped Read: 40 Stream Read/Write: 14481 Mapped Read/Write: 6 What is makeing the Stream Read/Write so unbelievably long? And as a read/write test, to me it looks a bit pointless to read the same integer over and over (if I understand well what's going on in the Stream Read/Write) Wouldn't it be better to read int's from the previously written file and just read and write ints on the same place? Is there a better way to illustrate it? I've been breaking my head about a lot of these things for a while and I just can't get the whole picture..

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  • Using Handlebars.js issue

    - by Roland
    I'm having a small issue when I'm compiling a template with Handlebars.js . I have a JSON text file which contains an big array with objects : Source ; and I'm using XMLHTTPRequest to get it and then parse it so I can use it when compiling the template. So far the template has the following structure : <div class="product-listing-wrapper"> <div class="product-listing"> <div class="left-side-content"> <div class="thumb-wrapper"> <img src="{{ThumbnailUrl}}"> </div> <div class="google-maps-wrapper"> <div class="google-coordonates-wrapper"> <div class="google-coordonates"> <p>{{LatLon.Lat}}</p> <p>{{LatLon.Lon}}</p> </div> </div> <div class="google-maps-button"> <a class="google-maps" href="#" data-latitude="{{LatLon.Lat}}" data-longitude="{{LatLon.Lon}}">Google Maps</a> </div> </div> </div> <div class="right-side-content"></div> </div> And the following block of code would be the way I'm handling the JS part : $(document).ready(function() { /* Default Javascript Options ~a javascript object which contains all the variables that will be passed to the cluster class */ var default_cluster_options = { animations : ['flash', 'bounce', 'shake', 'tada', 'swing', 'wobble', 'wiggle', 'pulse', 'flip', 'flipInX', 'flipOutX', 'flipInY', 'flipOutY', 'fadeIn', 'fadeInUp', 'fadeInDown', 'fadeInLeft', 'fadeInRight', 'fadeInUpBig', 'fadeInDownBig', 'fadeInLeftBig', 'fadeInRightBig', 'fadeOut', 'fadeOutUp', 'fadeOutDown', 'fadeOutLeft', 'fadeOutRight', 'fadeOutUpBig', 'fadeOutDownBig', 'fadeOutLeftBig', 'fadeOutRightBig', 'bounceIn', 'bounceInUp', 'bounceInDown', 'bounceInLeft', 'bounceInRight', 'bounceOut', 'bounceOutUp', 'bounceOutDown', 'bounceOutLeft', 'bounceOutRight', 'rotateIn', 'rotateInDownLeft', 'rotateInDownRight', 'rotateInUpLeft', 'rotateInUpRight', 'rotateOut', 'rotateOutDownLeft', 'rotateOutDownRight', 'rotateOutUpLeft', 'rotateOutUpRight', 'lightSpeedIn', 'lightSpeedOut', 'hinge', 'rollIn', 'rollOut'], json_data_url : 'data.json', template_data_url : 'template.php', base_maps_api_url : 'https://maps.googleapis.com/maps/api/js?sensor=false', cluser_wrapper_id : '#content-wrapper', maps_wrapper_class : '.google-maps', }; /* Cluster ~main class, handles all javascript operations */ var Cluster = function(environment, cluster_options) { var self = this; this.options = $.extend({}, default_cluster_options, cluster_options); this.environment = environment; this.animations = this.options.animations; this.json_data_url = this.options.json_data_url; this.template_data_url = this.options.template_data_url; this.base_maps_api_url = this.options.base_maps_api_url; this.cluser_wrapper_id = this.options.cluser_wrapper_id; this.maps_wrapper_class = this.options.maps_wrapper_class; this.test_environment_mode(this.environment); this.initiate_environment(); this.test_xmlhttprequest_availability(); this.initiate_gmaps_lib_load(self.base_maps_api_url); this.initiate_data_processing(); }; /* Test Environment Mode ~adds a modernizr test which looks wheater the cluster class is initiated in development or not */ Cluster.prototype.test_environment_mode = function(environment) { var self = this; return Modernizr.addTest('test_environment', function() { return (typeof environment !== 'undefined' && environment !== null && environment === "Development") ? true : false; }); }; /* Test XMLHTTPRequest Availability ~adds a modernizr test which looks wheater the xmlhttprequest class is available or not in the browser, exception makes IE */ Cluster.prototype.test_xmlhttprequest_availability = function() { return Modernizr.addTest('test_xmlhttprequest', function() { return (typeof window.XMLHttpRequest === 'undefined' || window.XMLHttpRequest === null) ? true : false; }); }; /* Initiate Environment ~depending on what the modernizr test returns it puts LESS in the development mode or not */ Cluster.prototype.initiate_environment = function() { return (Modernizr.test_environment) ? (less.env = "development", less.watch()) : true; }; Cluster.prototype.initiate_gmaps_lib_load = function(lib_url) { return Modernizr.load(lib_url); }; /* Initiate XHR Request ~prototype function that creates an xmlhttprequest for processing json data from an separate json text file */ Cluster.prototype.initiate_xhr_request = function(url, mime_type) { var request, data; var self = this; (Modernizr.test_xmlhttprequest) ? request = new ActiveXObject('Microsoft.XMLHTTP') : request = new XMLHttpRequest(); request.onreadystatechange = function() { if(request.readyState == 4 && request.status == 200) { data = request.responseText; } }; request.open("GET", url, false); request.overrideMimeType(mime_type); request.send(); return data; }; Cluster.prototype.initiate_google_maps_action = function() { var self = this; return $(this.maps_wrapper_class).each(function(index, element) { return $(element).on('click', function(ev) { var html = $('<div id="map-canvas" class="map-canvas"></div>'); var latitude = $(element).attr('data-latitude'); var longitude = $(element).attr('data-longitude'); log("LAT : " + latitude); log("LON : " + longitude); $.lightbox(html, { "width": 900, "height": 250, "onOpen" : function() { } }); ev.preventDefault(); }); }); }; Cluster.prototype.initiate_data_processing = function() { var self = this; var json_data = JSON.parse(self.initiate_xhr_request(self.json_data_url, 'application/json; charset=ISO-8859-1')); var source_data = self.initiate_xhr_request(self.template_data_url, 'text/html'); var template = Handlebars.compile(source_data); for(var i = 0; i < json_data.length; i++ ) { var result = template(json_data[i]); $(result).appendTo(self.cluser_wrapper_id); } self.initiate_google_maps_action(); }; /* Cluster ~initiate the cluster class */ var cluster = new Cluster("Development"); }); My problem would be that I don't think I'm iterating the JSON object right or I'm using the template the wrong way because if you check this link : http://rolandgroza.com/labs/valtech/ ; you will see that there are some numbers there ( which represents latitude and longitude ) but they are all the same and if you take only a brief look at the JSON object each number is different. So what am I doing wrong that it makes the same number repeat ? Or what should I do to fix it ? I must notice that I've just started working with templates so I have little knowledge it.

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  • css menu <ul><li> dinamically centered or width of buttons that covers the whole page

    - by Tony Stark
    I am building a home page for my minecraft server. Probably in the following 4-6 months I will opend my second and this is why I am in trouble. My first site is 1000 pixel wide, and the second will be 1200. First big difference. My menus are dinamically generated by my php code. It checks on my databases if there is another button or it is over. These buttons can be added or removed directly online. Another big issue is the browser compatibility. In a survey I did on our previous server I had a lot of users using: chrome, internet explorer, safari and firefox. That means that I must find a solution that is compatible with most browsers. What do I have to do? I came up with this CSS, which is touch compatible, it allows menus to be swapped to the left and it is enough to set 1 parameter to fix it for every page width. Sadly it is left aligned. body, nav, ul, li, a {margin: 0; padding: 0;} body {font-family: Verdana,"Helvetica Neue", Helvetica, Arial, sans-serif; } a {text-decoration: none;} .container { max-width: 900px; margin: 0px auto 0px auto; } .toggleMenu { display: none; background: #666; padding: 10px 15px; color: #999999; } .nav { border: 1px solid #424242; background-color: #121212; filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#686868', endColorstr='#121212'); background-image: -moz-linear-gradient(#686868, #121212); background-image: -webkit-gradient(linear, left top, left bottom, from(#686868), to(#121212)); background-image: -webkit-linear-gradient(#686868, #121212); background-image: -o-linear-gradient(#686868, #121212); background-image: -ms-linear-gradient(#686868, #121212); background-image: linear-gradient(#686868, #121212); -moz-box-shadow: 0 1px 1px #777, 0 1px 0 #666 inset; -webkit-box-shadow: 0 1px 1px #777, 0 1px 0 #666 inset; box-shadow: 0 1px 1px #777, 0 1px 0 #666 inset; list-style: none; *zoom: 1; position: relative; } .nav:before,.nav:after { content: " "; display: table; } .nav:after { clear: both; } .nav ul { list-style: none; width: 11em; z-index: 1; background-color: #121212; -moz-box-shadow: 0 -1px rgba(255,255,255,.3); -webkit-box-shadow: 0 -1px 0 rgba(255,255,255,.3); box-shadow: 0 -1px 0 rgba(255,255,255,.3); } .nav a { padding: 10px 15px; color:#999999; text-transform: uppercase; font: bold 11px Arial, Helvetica; text-decoration: none; text-shadow: 0 1px 0 #000; *zoom: 1; } .nav a:hover{ color:#000000; background-color: #B2B2B2; filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#D3D3D3', endColorstr='#B2B2B2'); background-image: -moz-linear-gradient(#D3D3D3, #B2B2B2); background-image: -webkit-gradient(linear, left top, left bottom, from(#D3D3D3), to(#B2B2B2)); background-image: -webkit-linear-gradient(#D3D3D3, #B2B2B2); background-image: -o-linear-gradient(#D3D3D3, #B2B2B2); background-image: -ms-linear-gradient(#D3D3D3, #B2B2B2); background-image: linear-gradient(#D3D3D3, #B2B2B2); } /*Delimitazione di ogni tab | HOME | */ .nav li { position: relative; border-right: 1px solid #424242; -moz-box-shadow: 1px 0 0 #686868; -webkit-box-shadow: 1px 0 0 #686868; box-shadow: 1px 0 0 #686868; } .nav > li { float: left; border-top: 1px solid #424242; z-index: 200; } .nav > li > .parent { background-image: url("../downArrow.png"); background-repeat: no-repeat; background-position: center right; } .nav > li li > .parent { background-image: url("../rightArrow.png"); background-repeat: no-repeat; background-position: center right; } .nav > li > a { display: block; } .nav li ul { position: absolute; left: -9999px; z-index: 100; } /* freccetta che indica un sottomenu nell'ultimo tab */ .nav > li:last-child li > .parent{ background-image: url("../leftArrow.png"); background-repeat: no-repeat; background-position: left; } /*flip subsubmenu*/ .nav li.last.hover > ul { left:auto; right: 0; } .nav > li.hover > ul { left: 0; } .nav li li.hover > ul { left: 100%; top: 0; } /* Spostare il 2^ sottomenu a sinistra */ .nav li.last li.hover ul { left:auto; right: 100%; top:0; } .nav li li a { display: block; background-color: #686868; -moz-box-shadow: 0 -1px rgba(255,255,255,.3); -webkit-box-shadow: 0 -1px 0 rgba(255,255,255,.3); box-shadow: 0 -1px 0 rgba(255,255,255,.3); z-index:100; border-top: 1px solid #686868; } .nav li li li a { background-color: #686868; -moz-box-shadow: 0 -1px rgba(255,255,255,.3); -webkit-box-shadow: 0 -1px 0 rgba(255,255,255,.3); box-shadow: 0 -1px 0 rgba(255,255,255,.3); z-index:200; border-top: 1px solid #686868; } .nav li li li li a { display: block; background-color: #686868; -moz-box-shadow: 0 -1px rgba(255,255,255,.3); -webkit-box-shadow: 0 -1px 0 rgba(255,255,255,.3); box-shadow: 0 -1px 0 rgba(255,255,255,.3); z-index:300; border-top: 1px solid #686868; } .nav li li li li a { background-color: #686868; -moz-box-shadow: 0 -1px rgba(255,255,255,.3); -webkit-box-shadow: 0 -1px 0 rgba(255,255,255,.3); box-shadow: 0 -1px 0 rgba(255,255,255,.3); z-index:400; border-top: 1px solid #686868; } @media screen and (max-width: 768px) { .active { display: block; } .nav > li { float: none; } .nav > li > .parent { background-position: 95% 50%; } .nav li li .parent { background-image: url("../downArrow.png"); background-repeat: no-repeat; background-position: 95% 50%; } .nav ul { display: block; width: 100%; } .nav > li.hover > ul , .nav li li.hover ul { position: static; } } My girlfriend (who adapted this code) is really busy for school and cannot help me. Leaving the borders on the whole square (page width), is it possible to make buttons cover the page width dinamically? Or is it possible to center the buttons? Thank you very much!

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  • Generating a drop down list of timezones with PHP

    - by Xeoncross
    Most sites need some way to show the dates on the site in the users preferred timezone. Below are two lists that I found and then one method using the built in PHP DateTime class in PHP 5. I need help knowing which of these would be the best to attempt to use when trying to get the UTC offset from the user on register. One: <option value="-12">[UTC - 12] Baker Island Time</option> <option value="-11">[UTC - 11] Niue Time, Samoa Standard Time</option> <option value="-10">[UTC - 10] Hawaii-Aleutian Standard Time, Cook Island Time</option> <option value="-9.5">[UTC - 9:30] Marquesas Islands Time</option> <option value="-9">[UTC - 9] Alaska Standard Time, Gambier Island Time</option> <option value="-8">[UTC - 8] Pacific Standard Time</option> <option value="-7">[UTC - 7] Mountain Standard Time</option> <option value="-6">[UTC - 6] Central Standard Time</option> <option value="-5">[UTC - 5] Eastern Standard Time</option> <option value="-4.5">[UTC - 4:30] Venezuelan Standard Time</option> <option value="-4">[UTC - 4] Atlantic Standard Time</option> <option value="-3.5">[UTC - 3:30] Newfoundland Standard Time</option> <option value="-3">[UTC - 3] Amazon Standard Time, Central Greenland Time</option> <option value="-2">[UTC - 2] Fernando de Noronha Time, South Georgia &amp; the South Sandwich Islands Time</option> <option value="-1">[UTC - 1] Azores Standard Time, Cape Verde Time, Eastern Greenland Time</option> <option value="0" selected="selected">[UTC] Western European Time, Greenwich Mean Time</option> <option value="1">[UTC + 1] Central European Time, West African Time</option> <option value="2">[UTC + 2] Eastern European Time, Central African Time</option> <option value="3">[UTC + 3] Moscow Standard Time, Eastern African Time</option> <option value="3.5">[UTC + 3:30] Iran Standard Time</option> <option value="4">[UTC + 4] Gulf Standard Time, Samara Standard Time</option> <option value="4.5">[UTC + 4:30] Afghanistan Time</option> <option value="5">[UTC + 5] Pakistan Standard Time, Yekaterinburg Standard Time</option> <option value="5.5">[UTC + 5:30] Indian Standard Time, Sri Lanka Time</option> <option value="5.75">[UTC + 5:45] Nepal Time</option> <option value="6">[UTC + 6] Bangladesh Time, Bhutan Time, Novosibirsk Standard Time</option> <option value="6.5">[UTC + 6:30] Cocos Islands Time, Myanmar Time</option> <option value="7">[UTC + 7] Indochina Time, Krasnoyarsk Standard Time</option> <option value="8">[UTC + 8] Chinese Standard Time, Australian Western Standard Time, Irkutsk Standard Time</option> <option value="8.75">[UTC + 8:45] Southeastern Western Australia Standard Time</option> <option value="9">[UTC + 9] Japan Standard Time, Korea Standard Time, Chita Standard Time</option> <option value="9.5">[UTC + 9:30] Australian Central Standard Time</option> <option value="10">[UTC + 10] Australian Eastern Standard Time, Vladivostok Standard Time</option> <option value="10.5">[UTC + 10:30] Lord Howe Standard Time</option> <option value="11">[UTC + 11] Solomon Island Time, Magadan Standard Time</option> <option value="11.5">[UTC + 11:30] Norfolk Island Time</option> <option value="12">[UTC + 12] New Zealand Time, Fiji Time, Kamchatka Standard Time</option> <option value="12.75">[UTC + 12:45] Chatham Islands Time</option> <option value="13">[UTC + 13] Tonga Time, Phoenix Islands Time</option> <option value="14">[UTC + 14] Line Island Time</option> Or using PHP friendly values: <option value="Pacific/Midway">(GMT-11:00) Midway Island, Samoa</option> <option value="America/Adak">(GMT-10:00) Hawaii-Aleutian</option> <option value="Etc/GMT+10">(GMT-10:00) Hawaii</option> <option value="Pacific/Marquesas">(GMT-09:30) Marquesas Islands</option> <option value="Pacific/Gambier">(GMT-09:00) Gambier Islands</option> <option value="America/Anchorage">(GMT-09:00) Alaska</option> <option value="America/Ensenada">(GMT-08:00) Tijuana, Baja California</option> <option value="Etc/GMT+8">(GMT-08:00) Pitcairn Islands</option> <option value="America/Los_Angeles">(GMT-08:00) Pacific Time (US & Canada)</option> <option value="America/Denver">(GMT-07:00) Mountain Time (US & Canada)</option> <option value="America/Chihuahua">(GMT-07:00) Chihuahua, La Paz, Mazatlan</option> <option value="America/Dawson_Creek">(GMT-07:00) Arizona</option> <option value="America/Belize">(GMT-06:00) Saskatchewan, Central America</option> <option value="America/Cancun">(GMT-06:00) Guadalajara, Mexico City, Monterrey</option> <option value="Chile/EasterIsland">(GMT-06:00) Easter Island</option> <option value="America/Chicago">(GMT-06:00) Central Time (US & Canada)</option> <option value="America/New_York">(GMT-05:00) Eastern Time (US & Canada)</option> <option value="America/Havana">(GMT-05:00) Cuba</option> <option value="America/Bogota">(GMT-05:00) Bogota, Lima, Quito, Rio Branco</option> <option value="America/Caracas">(GMT-04:30) Caracas</option> <option value="America/Santiago">(GMT-04:00) Santiago</option> <option value="America/La_Paz">(GMT-04:00) La Paz</option> <option value="Atlantic/Stanley">(GMT-04:00) Faukland Islands</option> <option value="America/Campo_Grande">(GMT-04:00) Brazil</option> <option value="America/Goose_Bay">(GMT-04:00) Atlantic Time (Goose Bay)</option> <option value="America/Glace_Bay">(GMT-04:00) Atlantic Time (Canada)</option> <option value="America/St_Johns">(GMT-03:30) Newfoundland</option> <option value="America/Araguaina">(GMT-03:00) UTC-3</option> <option value="America/Montevideo">(GMT-03:00) Montevideo</option> <option value="America/Miquelon">(GMT-03:00) Miquelon, St. Pierre</option> <option value="America/Godthab">(GMT-03:00) Greenland</option> <option value="America/Argentina/Buenos_Aires">(GMT-03:00) Buenos Aires</option> <option value="America/Sao_Paulo">(GMT-03:00) Brasilia</option> <option value="America/Noronha">(GMT-02:00) Mid-Atlantic</option> <option value="Atlantic/Cape_Verde">(GMT-01:00) Cape Verde Is.</option> <option value="Atlantic/Azores">(GMT-01:00) Azores</option> <option value="Europe/Belfast">(GMT) Greenwich Mean Time : Belfast</option> <option value="Europe/Dublin">(GMT) Greenwich Mean Time : Dublin</option> <option value="Europe/Lisbon">(GMT) Greenwich Mean Time : Lisbon</option> <option value="Europe/London">(GMT) Greenwich Mean Time : London</option> <option value="Africa/Abidjan">(GMT) Monrovia, Reykjavik</option> <option value="Europe/Amsterdam">(GMT+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna</option> <option value="Europe/Belgrade">(GMT+01:00) Belgrade, Bratislava, Budapest, Ljubljana, Prague</option> <option value="Europe/Brussels">(GMT+01:00) Brussels, Copenhagen, Madrid, Paris</option> <option value="Africa/Algiers">(GMT+01:00) West Central Africa</option> <option value="Africa/Windhoek">(GMT+01:00) Windhoek</option> <option value="Asia/Beirut">(GMT+02:00) Beirut</option> <option value="Africa/Cairo">(GMT+02:00) Cairo</option> <option value="Asia/Gaza">(GMT+02:00) Gaza</option> <option value="Africa/Blantyre">(GMT+02:00) Harare, Pretoria</option> <option value="Asia/Jerusalem">(GMT+02:00) Jerusalem</option> <option value="Europe/Minsk">(GMT+02:00) Minsk</option> <option value="Asia/Damascus">(GMT+02:00) Syria</option> <option value="Europe/Moscow">(GMT+03:00) Moscow, St. Petersburg, Volgograd</option> <option value="Africa/Addis_Ababa">(GMT+03:00) Nairobi</option> <option value="Asia/Tehran">(GMT+03:30) Tehran</option> <option value="Asia/Dubai">(GMT+04:00) Abu Dhabi, Muscat</option> <option value="Asia/Yerevan">(GMT+04:00) Yerevan</option> <option value="Asia/Kabul">(GMT+04:30) Kabul</option> <option value="Asia/Yekaterinburg">(GMT+05:00) Ekaterinburg</option> <option value="Asia/Tashkent">(GMT+05:00) Tashkent</option> <option value="Asia/Kolkata">(GMT+05:30) Chennai, Kolkata, Mumbai, New Delhi</option> <option value="Asia/Katmandu">(GMT+05:45) Kathmandu</option> <option value="Asia/Dhaka">(GMT+06:00) Astana, Dhaka</option> <option value="Asia/Novosibirsk">(GMT+06:00) Novosibirsk</option> <option value="Asia/Rangoon">(GMT+06:30) Yangon (Rangoon)</option> <option value="Asia/Bangkok">(GMT+07:00) Bangkok, Hanoi, Jakarta</option> <option value="Asia/Krasnoyarsk">(GMT+07:00) Krasnoyarsk</option> <option value="Asia/Hong_Kong">(GMT+08:00) Beijing, Chongqing, Hong Kong, Urumqi</option> <option value="Asia/Irkutsk">(GMT+08:00) Irkutsk, Ulaan Bataar</option> <option value="Australia/Perth">(GMT+08:00) Perth</option> <option value="Australia/Eucla">(GMT+08:45) Eucla</option> <option value="Asia/Tokyo">(GMT+09:00) Osaka, Sapporo, Tokyo</option> <option value="Asia/Seoul">(GMT+09:00) Seoul</option> <option value="Asia/Yakutsk">(GMT+09:00) Yakutsk</option> <option value="Australia/Adelaide">(GMT+09:30) Adelaide</option> <option value="Australia/Darwin">(GMT+09:30) Darwin</option> <option value="Australia/Brisbane">(GMT+10:00) Brisbane</option> <option value="Australia/Hobart">(GMT+10:00) Hobart</option> <option value="Asia/Vladivostok">(GMT+10:00) Vladivostok</option> <option value="Australia/Lord_Howe">(GMT+10:30) Lord Howe Island</option> <option value="Etc/GMT-11">(GMT+11:00) Solomon Is., New Caledonia</option> <option value="Asia/Magadan">(GMT+11:00) Magadan</option> <option value="Pacific/Norfolk">(GMT+11:30) Norfolk Island</option> <option value="Asia/Anadyr">(GMT+12:00) Anadyr, Kamchatka</option> <option value="Pacific/Auckland">(GMT+12:00) Auckland, Wellington</option> <option value="Etc/GMT-12">(GMT+12:00) Fiji, Kamchatka, Marshall Is.</option> <option value="Pacific/Chatham">(GMT+12:45) Chatham Islands</option> <option value="Pacific/Tongatapu">(GMT+13:00) Nuku'alofa</option> <option value="Pacific/Kiritimati">(GMT+14:00) Kiritimati</option> Or just using PHP it's self $timezones = DateTimeZone::listAbbreviations(); $cities = array(); foreach( $timezones as $key => $zones ) { foreach( $zones as $id => $zone ) { /** * Only get timezones explicitely not part of "Others". * @see http://www.php.net/manual/en/timezones.others.php */ if ( preg_match( '/^(America|Antartica|Arctic|Asia|Atlantic|Europe|Indian|Pacific)\//', $zone['timezone_id'] ) && $zone['timezone_id']) { $cities[$zone['timezone_id']][] = $key; } } } // For each city, have a comma separated list of all possible timezones for that city. foreach( $cities as $key => $value ) $cities[$key] = join( ', ', $value); // Only keep one city (the first and also most important) for each set of possibilities. $cities = array_unique( $cities ); // Sort by area/city name. ksort( $cities ); It seems like the last one would be the safest as it would grow with the PHP release being used. You could also flip that array around when needed to tie timezones to city names.

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  • Choosing a VS project type (C++)

    - by typoknig
    Hi all, I do not use C++ much (I try to stick to the easier stuff like Java and VB.NET), but the lately I have not had a choice. When I am picking a project type in VS for some C++ source I download, what project type should I pick? I had just been sticking with Win32 Console Applications, but I just downloaded some code (below) that will not work right even when it compiles with out errors. I have tried to use a CLR Console Application and an empty project too, and have changed many variables along the way, but I cannot get this code to work. I noticed that this code does not have "int main()" at its beginning, does that have something to do with it? Anyways, here is the code, got it from here: /* Demo of modified Lucas-Kanade optical flow algorithm. See the printf below */ #ifdef _CH_ #pragma package <opencv> #endif #ifndef _EiC #include "cv.h" #include "highgui.h" #include <stdio.h> #include <ctype.h> #endif #include <windows.h> #define FULL_IMAGE_AS_OUTPUT_FILE #define cvMirror cvFlip //IplImage *image = 0, *grey = 0, *prev_grey = 0, *pyramid = 0, *prev_pyramid = 0, *swap_temp; IplImage **buf = 0; IplImage *image1 = 0; IplImage *imageCopy=0; IplImage *image = 0; int win_size = 10; const int MAX_COUNT = 500; CvPoint2D32f* points[2] = {0,0}, *swap_points; char* status = 0; //int count = 0; //int need_to_init = 0; //int night_mode = 0; int flags = 0; //int add_remove_pt = 0; bool bLButtonDown = false; //bool bstopLoop = false; CvPoint pt, pt1,pt2; //IplImage* img1; FILE* FileDest; char* strImageDir = "E:\\Projects\\TSCreator\\Images"; char* strItemName = "b"; int imageCount=0; int bFirstFace = 1; // flag for first face int mode = 1; // Mode 1 - Haar Traing Sample Creation, 2 - HMM sample creation, Mode = 3 - Both Harr and HMM. //int startImgeNo = 1; bool isEqualRation = false; //Weidth to height ratio is equal //Selected Image data IplImage *selectedImage = 0; int selectedX = 0, selectedY = 0, currentImageNo = 0, selectedWidth = 0, selectedHeight= 0; CvRect selectedROI; void saveFroHarrTraining(IplImage *src, int x, int y, int width, int height, int imageCount); void saveForHMMTraining(IplImage *src, CvRect roi,int imageCount); // Code for draw ROI Cropping Image void on_mouse( int event, int x, int y, int flags, void* param ) { char f[200]; CvRect reg; if( !image ) return; if( event == CV_EVENT_LBUTTONDOWN ) { bLButtonDown = true; pt1.x = x; pt1.y = y; } else if ( event == CV_EVENT_MOUSEMOVE ) //Draw the selected area rectangle { pt2.x = x; pt2.y = y; if(bLButtonDown) { if( !image1 ) { /* allocate all the buffers */ image1 = cvCreateImage( cvGetSize(image), 8, 3 ); image1->origin = image->origin; points[0] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); points[1] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); status = (char*)cvAlloc(MAX_COUNT); flags = 0; } cvCopy( image, image1, 0 ); //Equal Weight-Height Ratio if(isEqualRation) { pt2.y = pt1.y + (pt2.x-pt1.x); } //Max Height and Width is the image width and height if(pt2.x>image->width) { pt2.x = image->width; } if(pt2.y>image->height) { pt2.y = image->height; } CvPoint InnerPt1 = pt1; CvPoint InnerPt2 = pt2; if ( InnerPt1.x > InnerPt2.x) { int tempX = InnerPt1.x; InnerPt1.x = InnerPt2.x; InnerPt2.x = tempX; } if ( pt2.y < InnerPt1.y ) { int tempY = InnerPt1.y; InnerPt1.y = InnerPt2.y; InnerPt2.y = tempY; } InnerPt1.y = image->height - InnerPt1.y; InnerPt2.y = image->height - InnerPt2.y; CvFont font; double hScale=1.0; double vScale=1.0; int lineWidth=1; cvInitFont(&font,CV_FONT_HERSHEY_SIMPLEX|CV_FONT_ITALIC, hScale,vScale,0,lineWidth); char size [200]; reg.x = pt1.x; reg.y = image->height - pt2.y; reg.height = abs (pt2.y - pt1.y); reg.width = InnerPt2.x -InnerPt1.x; //print width and heght of the selected reagion sprintf(size, "(%dx%d)",reg.width, reg.height); cvPutText (image1,size,cvPoint(10,10), &font, cvScalar(255,255,0)); cvRectangle(image1, InnerPt1, InnerPt2, CV_RGB(255,0,0), 1); //Mark Selected Reagion selectedImage = image; selectedX = pt1.x; selectedY = pt1.y; selectedWidth = reg.width; selectedHeight = reg.height; selectedROI = reg; //Show the modified image cvShowImage("HMM-Harr Positive Image Creator",image1); } } else if ( event == CV_EVENT_LBUTTONUP ) { bLButtonDown = false; // pt2.x = x; // pt2.y = y; // // if ( pt1.x > pt2.x) // { // int tempX = pt1.x; // pt1.x = pt2.x; // pt2.x = tempX; // } // // if ( pt2.y < pt1.y ) // { // int tempY = pt1.y; // pt1.y = pt2.y; // pt2.y = tempY; // // } // //reg.x = pt1.x; //reg.y = image->height - pt2.y; // //reg.height = abs (pt2.y - pt1.y); ////reg.width = reg.height/3; //reg.width = pt2.x -pt1.x; ////reg.height = (2 * reg.width)/3; #ifdef FULL_IMAGE_AS_OUTPUT_FILE CvRect FullImageRect; FullImageRect.x = 0; FullImageRect.y = 0; FullImageRect.width = image->width; FullImageRect.height = image->height; IplImage *regionFullImage =0; regionFullImage = cvCreateImage(cvSize (FullImageRect.width, FullImageRect.height), image->depth, image->nChannels); image->roi = NULL; //cvSetImageROI (image, FullImageRect); //cvCopy (image, regionFullImage, 0); #else IplImage *region =0; region = cvCreateImage(cvSize (reg.width, reg.height), image1->depth, image1->nChannels); image->roi = NULL; cvSetImageROI (image1, reg); cvCopy (image1, region, 0); #endif //cvNamedWindow("Result", CV_WINDOW_AUTOSIZE); //selectedImage = image; //selectedX = pt1.x; //selectedY = pt1.y; //selectedWidth = reg.width; //selectedHeight = reg.height; ////currentImageNo = startImgeNo; //selectedROI = reg; /*if(mode == 1) { saveFroHarrTraining(image,pt1.x,pt1.y,reg.width,reg.height,startImgeNo); } else if(mode == 2) { saveForHMMTraining(image,reg,startImgeNo); } else if(mode ==3) { saveFroHarrTraining(image,pt1.x,pt1.y,reg.width,reg.height,startImgeNo); saveForHMMTraining(image,reg,startImgeNo); } else { printf("Invalid mode."); } startImgeNo++;*/ } } /* Save popsitive samples for Harr Training. Also add an entry to the PositiveSample.txt with the location of the item of interest. */ void saveFroHarrTraining(IplImage *src, int x, int y, int width, int height, int imageCount) { char f[255] ; sprintf(f,"%s\\%s\\harr_%s%d%d.jpg",strImageDir,strItemName,strItemName,imageCount/10, imageCount%10); cvNamedWindow("Harr", CV_WINDOW_AUTOSIZE); cvShowImage("Harr", src); cvSaveImage(f, src); printf("output%d%d \t ", imageCount/10, imageCount%10); printf("width %d \t", width); printf("height %d \t", height); printf("x1 %d \t", x); printf("y1 %d \t\n", y); char f1[255]; sprintf(f1,"%s\\PositiveSample.txt",strImageDir); FileDest = fopen(f1, "a"); fprintf(FileDest, "%s\\harr_%s%d.jpg 1 %d %d %d %d \n",strItemName,strItemName, imageCount, x, y, width, height); fclose(FileDest); } /* Create Sample Images for HMM recognition algorythm trai ning. */ void saveForHMMTraining(IplImage *src, CvRect roi,int imageCount) { char f[255] ; printf("x=%d, y=%d, w= %d, h= %d\n",roi.x,roi.y,roi.width,roi.height); //Create the file name sprintf(f,"%s\\%s\\hmm_%s%d.pgm",strImageDir,strItemName,strItemName, imageCount); //Create storage for grayscale image IplImage* gray = cvCreateImage(cvSize(roi.width,roi.height), 8, 1); //Create storage for croped reagon IplImage* regionFullImage = cvCreateImage(cvSize(roi.width,roi.height),8,3); //Croped marked region cvSetImageROI(src,roi); cvCopy(src,regionFullImage); cvResetImageROI(src); //Flip croped image - otherwise it will saved upside down cvConvertImage(regionFullImage, regionFullImage, CV_CVTIMG_FLIP); //Convert croped image to gray scale cvCvtColor(regionFullImage,gray, CV_BGR2GRAY); //Show final grayscale image cvNamedWindow("HMM", CV_WINDOW_AUTOSIZE); cvShowImage("HMM", gray); //Save final grayscale image cvSaveImage(f, gray); } int maina( int argc, char** argv ) { CvCapture* capture = 0; //if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0]))) // capture = cvCaptureFromCAM( argc == 2 ? argv[1][0] - '0' : 0 ); //else if( argc == 2 ) // capture = cvCaptureFromAVI( argv[1] ); char* video; if(argc ==7) { mode = atoi(argv[1]); strImageDir = argv[2]; strItemName = argv[3]; video = argv[4]; currentImageNo = atoi(argv[5]); int a = atoi(argv[6]); if(a==1) { isEqualRation = true; } else { isEqualRation = false; } } else { printf("\nUsage: TSCreator.exe <Mode> <Sample Image Save Path> <Sample Image Save Directory> <Video File Location> <Start Image No> <Is Equal Ratio>\n"); printf("Mode = 1 - Haar Traing Sample Creation. \nMode = 2 - HMM sample creation.\nMode = 3 - Both Harr and HMM\n"); printf("Is Equal Ratio = 0 or 1. 1 - Equal weidth and height, 0 - custom."); printf("Note: You have to create the image save directory in correct path first.\n"); printf("Eg: TSCreator.exe 1 E:\Projects\TSCreator\Images A 11.avi 1 1\n\n"); return 0; } capture = cvCaptureFromAVI(video); if( !capture ) { fprintf(stderr,"Could not initialize capturing...\n"); return -1; } cvNamedWindow("HMM-Harr Positive Image Creator", CV_WINDOW_AUTOSIZE); cvSetMouseCallback("HMM-Harr Positive Image Creator", on_mouse, 0); //cvShowImage("Test", image1); for(;;) { IplImage* frame = 0; int i, k, c; frame = cvQueryFrame( capture ); if( !frame ) break; if( !image ) { /* allocate all the buffers */ image = cvCreateImage( cvGetSize(frame), 8, 3 ); image->origin = frame->origin; //grey = cvCreateImage( cvGetSize(frame), 8, 1 ); //prev_grey = cvCreateImage( cvGetSize(frame), 8, 1 ); //pyramid = cvCreateImage( cvGetSize(frame), 8, 1 ); // prev_pyramid = cvCreateImage( cvGetSize(frame), 8, 1 ); points[0] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); points[1] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); status = (char*)cvAlloc(MAX_COUNT); flags = 0; } cvCopy( frame, image, 0 ); // cvCvtColor( image, grey, CV_BGR2GRAY ); cvShowImage("HMM-Harr Positive Image Creator", image); cvSetMouseCallback("HMM-Harr Positive Image Creator", on_mouse, 0); c = cvWaitKey(0); if((char)c == 's') { //Save selected reagion as training data if(selectedImage) { printf("Selected Reagion Saved\n"); if(mode == 1) { saveFroHarrTraining(selectedImage,selectedX,selectedY,selectedWidth,selectedHeight,currentImageNo); } else if(mode == 2) { saveForHMMTraining(selectedImage,selectedROI,currentImageNo); } else if(mode ==3) { saveFroHarrTraining(selectedImage,selectedX,selectedY,selectedWidth,selectedHeight,currentImageNo); saveForHMMTraining(selectedImage,selectedROI,currentImageNo); } else { printf("Invalid mode."); } currentImageNo++; } } } cvReleaseCapture( &capture ); //cvDestroyWindow("HMM-Harr Positive Image Creator"); cvDestroyAllWindows(); return 0; } #ifdef _EiC main(1,"lkdemo.c"); #endif If I put... #include "stdafx.h" int _tmain(int argc, _TCHAR* argv[]) { return 0; } ... before the previous code (and link it to the correct OpenCV .lib files) it compiles without errors, but does nothing at the command line. How do I make it work?

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  • Null reading in stream images? Unable to start activity ComponentInfo

    - by lasmith
    I have reviewed a lot of similar questions regarding not being able to launch an activity but they don't seem to quite match my problem. I am working on a simple black jack game but its force quitting. I suspect there is a problem with loading up the card png images I have. Stepping through the debugger it crashes right while in the resetGame() function. I'm sure I am doing something dumb. My Logcat: 10-15 20:21:43.309: E/AndroidRuntime(2863): FATAL EXCEPTION: main 10-15 20:21:43.309: E/AndroidRuntime(2863): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.smith.blackjack/com.smith.blackjack.Main}: java.lang.NullPointerException 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.ActivityThread.access$600(ActivityThread.java:130) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.os.Handler.dispatchMessage(Handler.java:99) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.os.Looper.loop(Looper.java:137) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.ActivityThread.main(ActivityThread.java:4745) 10-15 20:21:43.309: E/AndroidRuntime(2863): at java.lang.reflect.Method.invokeNative(Native Method) 10-15 20:21:43.309: E/AndroidRuntime(2863): at java.lang.reflect.Method.invoke(Method.java:511) 10-15 20:21:43.309: E/AndroidRuntime(2863): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 10-15 20:21:43.309: E/AndroidRuntime(2863): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 10-15 20:21:43.309: E/AndroidRuntime(2863): at dalvik.system.NativeStart.main(Native Method) 10-15 20:21:43.309: E/AndroidRuntime(2863): Caused by: java.lang.NullPointerException 10-15 20:21:43.309: E/AndroidRuntime(2863): at com.smith.blackjack.DeckOfCards.<init>(DeckOfCards.java:17) 10-15 20:21:43.309: E/AndroidRuntime(2863): at com.smith.blackjack.Main.resetGame(Main.java:98) 10-15 20:21:43.309: E/AndroidRuntime(2863): at com.smith.blackjack.Main.onCreate(Main.java:67) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.Activity.performCreate(Activity.java:5008) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 10-15 20:21:43.309: E/AndroidRuntime(2863): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 10-15 20:21:43.309: E/AndroidRuntime(2863): ... 11 more My androidmanifest: <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.smith.blackjack" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="11" android:targetSdkVersion="15" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".Main" android:label="@string/title_activity_main" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> Here is my Main.java package com.smith.blackjack; import android.os.Bundle; import android.app.Activity; import android.content.res.AssetManager; import android.graphics.drawable.Drawable; import java.io.IOException; import java.io.InputStream; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ImageView; public class Main extends Activity { private ImageView dealerCard0; private ImageView dealerCard1; private ImageView dealerCard2; private ImageView dealerCard3; private ImageView playerCard0; private ImageView playerCard1; private ImageView playerCard2; private ImageView playerCard3; private ImageView imgResult; private Button btnDeal; private Button btnDraw; private Button btnHold; private DeckOfCards deckOfCards; private int[] dealerValues; private int dealerSum; private int dealerCardNumber; private int[] playerValues; private int playerSum; private int playerCardNumber; private InputStream dealerHiddenCard; private Card dealerCard; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); dealerCard0 = (ImageView) findViewById(R.id.dealerCard0); dealerCard1 = (ImageView) findViewById(R.id.dealerCard1); dealerCard2 = (ImageView) findViewById(R.id.dealerCard2); dealerCard3 = (ImageView) findViewById(R.id.dealerCard3); playerCard0 = (ImageView) findViewById(R.id.playerCard0); playerCard1 = (ImageView) findViewById(R.id.playerCard1); playerCard2 = (ImageView) findViewById(R.id.playerCard2); playerCard3 = (ImageView) findViewById(R.id.playerCard3); imgResult = (ImageView) findViewById(R.id.imgResult); btnDeal = (Button) findViewById(R.id.deal); btnDraw = (Button) findViewById(R.id.draw); btnHold = (Button) findViewById(R.id.hold); btnDeal.setOnClickListener(btnDealListener); btnDraw.setOnClickListener(btnDrawListener); btnHold.setOnClickListener(btnHoldListener); resetGame(); } private void resetGame(){ AssetManager assets = getAssets(); dealerValues = new int[4]; playerValues = new int[4]; dealerSum = 0; playerSum = 0; dealerCardNumber = 0; playerCardNumber = 0; for (int i = 0; i < 4; i++) { dealerValues[i] = 0; playerValues[i] = 0; } try { InputStream stream = assets.open("cardback.png"); // stream = assets.open("cardback.png"); Drawable cardImage = Drawable.createFromStream(stream, null); dealerCard0.setImageDrawable(cardImage); dealerCard1.setImageDrawable(cardImage); dealerCard2.setImageDrawable(cardImage); dealerCard3.setImageDrawable(cardImage); playerCard0.setImageDrawable(cardImage); playerCard1.setImageDrawable(cardImage); playerCard2.setImageDrawable(cardImage); playerCard3.setImageDrawable(cardImage); imgResult.setImageDrawable(cardImage); deckOfCards = new DeckOfCards(); deckOfCards.shuffle(); assets.close(); } catch (IOException e){ Log.e("Reset Game", "Error Loading", e); } } public OnClickListener btnDealListener = new OnClickListener() { // @Override public void onClick(View v) { try { AssetManager assets = getAssets(); InputStream stream; // first player card Card newCard; newCard = deckOfCards.dealCard(); playerValues[playerCardNumber] = newCard.faceValue; playerCardNumber++; stream = assets.open(newCard.File); Drawable cardImage = Drawable.createFromStream(stream, newCard.File); playerCard0.setImageDrawable(cardImage); assets.close(); // second player card newCard = deckOfCards.dealCard(); playerValues[playerCardNumber] = newCard.faceValue; playerCardNumber++; stream = assets.open(newCard.File); cardImage = Drawable.createFromStream(stream, newCard.File); playerCard1.setImageDrawable(cardImage); assets.close(); // first dealer card hidden newCard = deckOfCards.dealCard(); dealerCard = newCard; dealerValues[dealerCardNumber] = newCard.faceValue; dealerCardNumber++; dealerHiddenCard = assets.open(newCard.File); stream = assets.open("cardback.png"); cardImage = Drawable.createFromStream(stream, "cardback"); dealerCard0.setImageDrawable(cardImage); assets.close(); // second dealer card open newCard = deckOfCards.dealCard(); dealerValues[dealerCardNumber] = newCard.faceValue; dealerCardNumber++; stream = assets.open(newCard.File); cardImage = Drawable.createFromStream(stream, newCard.File); dealerCard1.setImageDrawable(cardImage); assets.close(); } catch (IOException e){ Log.e("Deal", "Error Loading", e); } }; }; public OnClickListener btnDrawListener = new OnClickListener() { // @Override public void onClick(View v) { try { AssetManager assets = getAssets(); InputStream stream; // get next player card Card newCard; newCard = deckOfCards.dealCard(); playerValues[playerCardNumber] = newCard.faceValue; playerCardNumber++; stream = assets.open(newCard.File); Drawable cardImage = Drawable.createFromStream(stream, newCard.File); switch (playerCardNumber){ case 3: playerCard2.setImageDrawable(cardImage); case 4: playerCard3.setImageDrawable(cardImage); } assets.close(); } catch (IOException e){ Log.e("Draw", "Error Loading", e); } }; }; public OnClickListener btnHoldListener = new OnClickListener() { // @Override public void onClick(View v) { Drawable cardImage; // evaluate player hand playerSum = evaluate(playerValues); if (playerSum > 21){ // player losses } // flip over the dealer hidden card cardImage = Drawable.createFromStream(dealerHiddenCard, dealerCard.File); Card newCard; InputStream stream; AssetManager assets = getAssets(); for (int i=2; i<4; i++){ dealerSum = evaluate(dealerValues); if (dealerSum < 16 ) { newCard = deckOfCards.dealCard(); dealerValues[dealerCardNumber] = newCard.faceValue; dealerCardNumber++; try { stream = assets.open(newCard.File); cardImage = Drawable.createFromStream(stream, newCard.File); switch (dealerCardNumber){ case 3: dealerCard2.setImageDrawable(cardImage); case 4: dealerCard3.setImageDrawable(cardImage); } assets.close(); } catch (IOException e){ Log.e("Draw", "Error Loading", e); } if (dealerSum < playerSum) { // player wins } if (dealerSum > playerSum){ // dealer wins } if (dealerSum == playerSum){ // it is a draw } } } }; }; public int evaluate (int[]values) { int sumCards = 0; for (int i = 0; i < 4; i++){ sumCards += values[i]; } if (sumCards > 21) { for (int i = 0; i < 4; i++){ if (values[i] == 11) { values[i] = 1; sumCards -= 10; continue; } } } return sumCards; } } My DeckOfCards class: package com.smith.blackjack; import java.util.Random; public class DeckOfCards { private Card [] deck; private int currentCard; private static final int NUMBER_OF_CARDS = 52; private static final Random randomNumbers = new Random(); public DeckOfCards () { deck = new Card[NUMBER_OF_CARDS]; currentCard = 0 ; for(int count = 0; count < deck.length; count++) { deck[count].faceValue = count + 1; } } public void shuffle () { currentCard = 0; for (int first = 0; first < deck.length; first ++){ int second = randomNumbers.nextInt(NUMBER_OF_CARDS); int temp = deck[first].faceValue; deck[first].faceValue=deck[second].faceValue; deck[second].faceValue = temp; } } public Card dealCard(){ Card temp = new Card(); temp.faceValue = 0; temp.File = ""; if(currentCard < deck.length) { temp.faceValue = deck[currentCard].faceValue / 4; int suit = deck[currentCard].faceValue % 4; String suitString = ""; switch (suit){ case 0: suitString = "c"; case 1: suitString = "d"; case 2: suitString = "h"; case 3: suitString = "s"; } Integer face = temp.faceValue / 4 ; String faceString = face.toString(); temp.File = faceString + suitString + ".png"; switch (temp.faceValue){ case 11: temp.faceValue = 10; case 12: temp.faceValue = 10; case 13: temp.faceValue = 10; } return temp; } else return temp; } }

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  • Thread not behaving correctly

    - by ivor
    Hello, I wonder if anyone can help me to understand where I could be going wrong with this code; Basically I'm working on a turorial and calling the class below from another class - and it is getting the following error; Exception in thread "Thread-1" java.lang.NullPointerException at org.newdawn.spaceinvaders.TCPChat.run(TCPChat.java:322) at java.lang.Thread.run(Unknown Source) I realise the error is beibg flagged in another class- but I have tested the other class with a small class which sets up a separate thread - and it works fine, but as soon as I try and implement a new thread in this class - it causes all sorts of problems. Am I setting up the thread correctly in this class? Basically I can set up a thread in this class, with a test loop and it's fine, but when I bring in the functionality of the rest of the game it sometimes hangs, or does not display at all. Any suggestions on where I could be going wrong would be greatly appreciated. Thanks for looking. package org.newdawn.spaceinvaders; import java.awt.BorderLayout; import java.awt.Canvas; import java.awt.Color; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.image.BufferStrategy; import java.util.ArrayList; import java.util.Scanner; import java.awt.*;//maybe not needed import javax.swing.*;//maybenot needed import java.util.Random; //import java.io.*; /** * The main hook of our game. This class with both act as a manager * for the display and central mediator for the game logic. * * Display management will consist of a loop that cycles round all * entities in the game asking them to move and then drawing them * in the appropriate place. With the help of an inner class it * will also allow the player to control the main ship. * * As a mediator it will be informed when entities within our game * detect events (e.g. alient killed, played died) and will take * appropriate game actions. * * @author Kevin Glass */ public class Game extends Canvas implements Runnable{ /** The stragey that allows us to use accelerate page flipping */ private BufferStrategy strategy; /** True if the game is currently "running", i.e. the game loop is looping */ private boolean gameRunning = true; /** The list of all the entities that exist in our game */ private ArrayList entities = new ArrayList(); /** The list of entities that need to be removed from the game this loop */ private ArrayList removeList = new ArrayList(); /** The entity representing the player */ private Entity ship; /** The speed at which the player's ship should move (pixels/sec) */ private double moveSpeed = 300; /** The time at which last fired a shot */ private long lastFire = 0; /** The interval between our players shot (ms) */ private long firingInterval = 500; /** The number of aliens left on the screen */ private int alienCount; /** The number of levels progressed */ private double levelCount; /** high score for the user */ private int highScore; /** high score for the user */ private String player = "bob"; //private GetUserInput getPlayer; /** The list of entities that need to be removed from the game this loop */ /** The message to display which waiting for a key press */ private String message = ""; /** True if we're holding up game play until a key has been pressed */ private boolean waitingForKeyPress = true; /** True if the left cursor key is currently pressed */ private boolean leftPressed = false; /** True if the right cursor key is currently pressed */ private boolean rightPressed = false; /** True if we are firing */ private boolean firePressed = false; /** True if game logic needs to be applied this loop, normally as a result of a game event */ private boolean logicRequiredThisLoop = false; //private Thread cThread = new Thread(this); //public Thread t = new Thread(this); //private Thread g = new Thread(this); void setHighscore(int setHS) { highScore = setHS; } public int getHighscore() { return highScore; } public void setPlayer(String setPlayer) { player = setPlayer; } public String getPlayer() { return player; } public void run() { //setup(); System.out.println("hello im running bob"); /*int count = 1; do { System.out.println("Count is: " + count); count++; try{Thread.sleep(1);} catch(InterruptedException e){} } while (count <= 2000000);*/ //Game g =new Game(); //Game g = this; // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //setup(); //this.gameLoop(); //try{thread.sleep(1);} //catch{InterruptedException e} } /** * Construct our game and set it running. */ public Game () { //Thread t = new Thread(this);//set up new thread for invaders game //t.run();//run the run method of the game //Game g =new Game(); //setup(); //Thread t = new Thread(this); //thread.start(); //SwingUtilities.invokeLater(this); Thread er = new Thread(this); er.start(); } public void setup(){ //initialise highscore setHighscore(0); // create a frame to contain our game JFrame container = new JFrame("Space Invaders 101"); // get hold the content of the frame and set up the resolution of the game JPanel panel = (JPanel) container.getContentPane(); panel.setPreferredSize(new Dimension(800,600)); //panel.setLayout(null); // setup our canvas size and put it into the content of the frame setBounds(0,0,800,600); panel.add(this); // Tell AWT not to bother repainting our canvas since we're // going to do that our self in accelerated mode setIgnoreRepaint(true); // finally make the window visible container.pack(); container.setResizable(false); container.setVisible(true); // add a listener to respond to the user closing the window. If they // do we'd like to exit the game container.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { //cThread.interrupt(); System.exit(0); } }); // add a key input system (defined below) to our canvas // so we can respond to key pressed addKeyListener(new KeyInputHandler()); // request the focus so key events come to us requestFocus(); // create the buffering strategy which will allow AWT // to manage our accelerated graphics createBufferStrategy(2); strategy = getBufferStrategy(); // initialise the entities in our game so there's something // to see at startup initEntities(); } /** * Start a fresh game, this should clear out any old data and * create a new set. */ private void startGame() { // clear out any existing entities and intialise a new set entities.clear(); initEntities(); //initialise highscore setHighscore(0); // blank out any keyboard settings we might currently have leftPressed = false; rightPressed = false; firePressed = false; } /** * Initialise the starting state of the entities (ship and aliens). Each * entitiy will be added to the overall list of entities in the game. */ //private void initEntities() { public void initEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = 1.02; for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){ //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",100+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } } //private void initEntities() { public void initAlienEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal //ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side //entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = levelCount + 0.10;//this increases the speed on every level for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){//randome check to show alien //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",-250+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } advanceAlienSpeed(levelCount); } /** * Notification from a game entity that the logic of the game * should be run at the next opportunity (normally as a result of some * game event) */ public void updateLogic() { logicRequiredThisLoop = true; } /** * Remove an entity from the game. The entity removed will * no longer move or be drawn. * * @param entity The entity that should be removed */ public void removeEntity(Entity entity) { removeList.add(entity); } /** * Notification that the player has died. */ public void notifyDeath() { message = "Oh no! They got you, try again?"; waitingForKeyPress = true; } /** * Notification that the player has won since all the aliens * are dead. */ public void notifyWin() { message = "Well done! You Win!"; waitingForKeyPress = true; } /** * Notification that an alien has been killed */ public void notifyAlienKilled() { // reduce the alient count, if there are none left, the player has won! alienCount--; if (alienCount == 0) { //notifyWin();win not relevant here... this.initAlienEntities();//call fresh batch of aliens } // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens advanceAlienSpeed(1.30); } public void advanceAlienSpeed(double speed) { // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); if (entity instanceof AlienEntity) { // speed up by 2% entity.setHorizontalMovement(entity.getHorizontalMovement() * speed); //entity.setVerticalMovement(entity.getVerticalMovement() * 1.02); } } } /** * Attempt to fire a shot from the player. Its called "try" * since we must first check that the player can fire at this * point, i.e. has he/she waited long enough between shots */ public void tryToFire() { // check that we have waiting long enough to fire if (System.currentTimeMillis() - lastFire < firingInterval) { return; } // if we waited long enough, create the shot entity, and record the time. lastFire = System.currentTimeMillis(); ShotEntity shot = new ShotEntity(this,"sprites/shot.gif",ship.getX()+10,ship.getY()-30); entities.add(shot); } /** * The main game loop. This loop is running during all game * play as is responsible for the following activities: * <p> * - Working out the speed of the game loop to update moves * - Moving the game entities * - Drawing the screen contents (entities, text) * - Updating game events * - Checking Input * <p> */ public void gameLoop() { long lastLoopTime = System.currentTimeMillis(); // keep looping round til the game ends while (gameRunning) { // work out how long its been since the last update, this // will be used to calculate how far the entities should // move this loop long delta = System.currentTimeMillis() - lastLoopTime; lastLoopTime = System.currentTimeMillis(); // Get hold of a graphics context for the accelerated // surface and blank it out Graphics2D g = (Graphics2D) strategy.getDrawGraphics(); g.setColor(Color.black); g.fillRect(0,0,800,600); // cycle round asking each entity to move itself if (!waitingForKeyPress) { for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.move(delta); } } // cycle round drawing all the entities we have in the game for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.draw(g); } // brute force collisions, compare every entity against // every other entity. If any of them collide notify // both entities that the collision has occured for (int p=0;p<entities.size();p++) { for (int s=p+1;s<entities.size();s++) { Entity me = (Entity) entities.get(p); Entity him = (Entity) entities.get(s); if (me.collidesWith(him)) { me.collidedWith(him); him.collidedWith(me); } } } // remove any entity that has been marked for clear up entities.removeAll(removeList); removeList.clear(); // if a game event has indicated that game logic should // be resolved, cycle round every entity requesting that // their personal logic should be considered. if (logicRequiredThisLoop) { //g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.doLogic(); } logicRequiredThisLoop = false; } // if we're waiting for an "any key" press then draw the // current message //show highscore at top of screen //show name at top of screen g.setColor(Color.white); g.drawString("Player : "+getPlayer()+" : Score : "+getHighscore(),20,20); if (waitingForKeyPress) { g.setColor(Color.white); g.drawString(message,(800-g.getFontMetrics().stringWidth(message))/2,250); g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); } // finally, we've completed drawing so clear up the graphics // and flip the buffer over g.dispose(); strategy.show(); // resolve the movement of the ship. First assume the ship // isn't moving. If either cursor key is pressed then // update the movement appropraitely ship.setVerticalMovement(0);//set to vertical movement if ((leftPressed) && (!rightPressed)) { ship.setVerticalMovement(-moveSpeed);//**took out setHorizaontalMOvement } else if ((rightPressed) && (!leftPressed)) { ship.setVerticalMovement(moveSpeed);//**took out setHorizaontalMOvement } // if we're pressing fire, attempt to fire if (firePressed) { tryToFire(); } // finally pause for a bit. Note: this should run us at about // 100 fps but on windows this might vary each loop due to // a bad implementation of timer try { Thread.sleep(10); } catch (Exception e) {} } } /** * A class to handle keyboard input from the user. The class * handles both dynamic input during game play, i.e. left/right * and shoot, and more static type input (i.e. press any key to * continue) * * This has been implemented as an inner class more through * habbit then anything else. Its perfectly normal to implement * this as seperate class if slight less convienient. * * @author Kevin Glass */ private class KeyInputHandler extends KeyAdapter { /** The number of key presses we've had while waiting for an "any key" press */ private int pressCount = 1; /** * Notification from AWT that a key has been pressed. Note that * a key being pressed is equal to being pushed down but *NOT* * released. Thats where keyTyped() comes in. * * @param e The details of the key that was pressed */ public void keyPressed(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "press" if (waitingForKeyPress) { return; } // if (e.getKeyCode() == KeyEvent.VK_LEFT) { ////leftPressed = true; ///} //// if (e.getKeyCode() == KeyEvent.VK_RIGHT) { //rightPressed = true; if (e.getKeyCode() == KeyEvent.VK_UP) { leftPressed = true; } if (e.getKeyCode() == KeyEvent.VK_DOWN) { rightPressed = true; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = true; } } /** * Notification from AWT that a key has been released. * * @param e The details of the key that was released */ public void keyReleased(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "released" if (waitingForKeyPress) { return; } if (e.getKeyCode() == KeyEvent.VK_UP) {//changed from VK_LEFT leftPressed = false; } if (e.getKeyCode() == KeyEvent.VK_DOWN) {//changed from VK_RIGHT rightPressed = false; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = false; } } /** * Notification from AWT that a key has been typed. Note that * typing a key means to both press and then release it. * * @param e The details of the key that was typed. */ public void keyTyped(KeyEvent e) { // if we're waiting for a "any key" type then // check if we've recieved any recently. We may // have had a keyType() event from the user releasing // the shoot or move keys, hence the use of the "pressCount" // counter. if (waitingForKeyPress) { if (pressCount == 1) { // since we've now recieved our key typed // event we can mark it as such and start // our new game waitingForKeyPress = false; startGame(); pressCount = 0; } else { pressCount++; } } // if we hit escape, then quit the game if (e.getKeyChar() == 27) { //cThread.interrupt(); System.exit(0); } } } /** * The entry point into the game. We'll simply create an * instance of class which will start the display and game * loop. * * @param argv The arguments that are passed into our game */ //public static void main(String argv[]) { //Game g =new Game(); // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //g.gameLoop(); //} }

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