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• Package Manager Console For More Than Managing Packages

  - by Steve Michelotti

  Like most developers, I prefer to not have to pick up the mouse if I don’t have to. I use the Executor launcher for almost everything so it’s extremely rare for me to ever click the “Start” button in Windows. I also use shortcuts keys when I can so I don’t have to pick up the mouse. By now most people know that the Package Manager Console that comes with NuGet is PowerShell embedded inside of Visual Studio. It is based on its PowerConsole predecessor which was the first (that I’m aware of) to embed PowerShell inside of Visual Studio and give access to the Visual Studio automation DTE object. It does this through an inherent $dte variable that is automatically available and ready for use. This variable is also available inside of the NuGet Package Manager console. Adding a new class file to a Visual Studio project is one of those mundane tasks that should be easier. First I have to pick up the mouse. Then I have to right-click where I want it file to go and select “Add –> New Item…” or “Add –> Class…”   If you know the Ctrl+Shift+A shortcut, then you can avoid the mouse for adding a new item but you have to manually assign a shortcut for adding a new class. At this point it pops up a dialog just so I can enter the name of the class I want. Since this is one of the most common tasks developers do, I figure there has to be an easier way and a way that avoids picking up the mouse and popping up dialogs. This is where your embedded PowerShell prompt in Visual Studio comes in. The first thing you should do is to assign a keyboard shortcut so that you can get a PowerShell prompt (i.e., the Package Manager console) quickly without ever picking up the mouse. I assign “Ctrl+P, Ctrl+M” because “P + M” stands for “Package Manager” so it is easy to remember:   At this point I can type this command to add a new class: PM> $dte.ItemOperations.AddNewItem("Code\Class", "Foo.cs") which will result in the class being added: At this point I’ve satisfied my original goal of not having to pick up a mouse and not having the “Add New Item” dialog pop up. However, having to remember that $dte method call is not very user-friendly at all. The best thing to do is to make this a re-usable function that always loads when Visual Studio starts up. There is a $profile variable that you can use to figure out where that location is for your machine: PM> $profile C:\Users\steve.michelotti\Documents\WindowsPowerShell\NuGet_profile.ps1 If the NuGet_profile.ps1 file does not already exist, you can just create it yourself and place it in the directory. Now you can put a function inside like this: 1: function addClass($className) 2: { 3: if ($className.EndsWith(".cs") -eq $false) { 4: $className = $className + ".cs" 5: } 6: 7: $dte.ItemOperations.AddNewItem("Code\Class", $className) 8: } Since it’s in the NuGet_profile.ps1 file, this function will automatically always be available for me after starting Visual Studio. Now I can simply do this: PM> addClass Foo At this point, we have a *very* nice developer experience. All I did to add a new class was: “Ctrl-P, Ctrl-M”, then “addClass Foo”. No mouse, no pop up dialogs, no complex commands to remember. In fact, PowerShell gives you auto-completion as well. If I type “addc” followed by [TAB], then intellisense pops up: You can see my custom function appear in intellisense above. Now I can type the next letter “c” and [TAB] to auto-complete the command. And if that’s still too many key strokes for you, then you can create your own PowerShell custom alias for your function like this: PM> Set-Alias addc addClass PM> addc Foo While all this is very useful, I did run into some issues which prompted me to make even further customization. This command will add the new class file to the current active directory. Depending on your context, this may not be what you want. For example, by convention all view model objects go in the “Models” folder in an MVC project. So if the current document is in the Controllers folder, it will add your class to that folder which is not what you want. You want it to always add it to the “Models” folder if you are adding a new model in an MVC project. For this situation, I added a new function called “addModel” which looks like this: 1: function addModel($className) 2: { 3: if ($className.EndsWith(".cs") -eq $false) { 4: $className = $className + ".cs" 5: } 6: 7: $modelsDir = $dte.ActiveSolutionProjects[0].UniqueName.Replace(".csproj", "") + "\Models" 8: $dte.Windows.Item([EnvDTE.Constants]::vsWindowKindSolutionExplorer).Activate() 9: $dte.ActiveWindow.Object.GetItem($modelsDir).Select([EnvDTE.vsUISelectionType]::vsUISelectionTypeSelect) 10: $dte.ItemOperations.AddNewItem("Code\Class", $className) 11: } First I figure out the path to the Models directory on line #7. Then I activate the Solution Explorer window on line #8. Then I make sure the Models directory is selected so that my context is correct when I add the new class and it will be added to the Models directory as desired. These are just a couple of examples for things you can do with the PowerShell prompt that you have available in the Package Manager console. As developers we spend so much time in Visual Studio, why would you not customize it so that you can work in whatever way you want to work?! The next time you’re not happy about the way Visual Studio makes you do a particular task – automate it! The sky is the limit.

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• Extending Currying: Partial Functions in Javascript

  - by kerry

  Last week I posted about function currying in javascript.  This week I am taking it a step further by adding the ability to call partial functions. Suppose we have a graphing application that will pull data via Ajax and perform some calculation to update a graph.  Using a method with the signature ‘updateGraph(id,value)’. To do this, we have do something like this: 1: for(var i=0;i<objects.length;i++) { 2: Ajax.request('/some/data',{id:objects[i].id},function(json) { 3: updateGraph(json.id, json.value); 4: } 5: } This works fine.  But, using this method we need to return the id in the json response from the server.  This works fine, but is not that elegant and increase network traffic. Using partial function currying we can bind the id parameter and add the second parameter later (when returning from the asynchronous call).  To do this, we will need the updated curry method.  I have added support for sending additional parameters at runtime for curried methods. 1: Function.prototype.curry = function(scope) { 2: scope = scope || window 3: var args = []; 4: for (var i=1, len = arguments.length; i < len; ++i) { 5: args.push(arguments[i]); 6: } 7: var m = this; 8: return function() { 9: for (var i=0, len = arguments.length; i < len; ++i) { 10: args.push(arguments[i]); 11: } 12: return m.apply(scope, args); 13: }; 14: } To partially curry this method we will call the curry method with the id parameter, then the request will callback on it with just the value.  Any additional parameters are appended to the method call. 1: for(var i=0;i<objects.length;i++) { 2: var id=objects[i].id; 3: Ajax.request('/some/data',{id: id}, updateGraph.curry(id)); 4: } As you can see, partial currying gives is a very useful tool and this simple method should be a part of every developer’s toolbox.

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• Multiple validation using jquery

  - by Prasenjit

  <script type="text/javascript">           $(document).ready(                 function() {                     $("input[id$='btnOK']").click(function(event) {                         $("#form1").validate({                             rules: {                                 txtName: { required: true },                                 txtEmail: { required: true, email: true },                                 txtPostalAddress: { required: true, maxlength: 50 }                             },                             messages: {}, onsubmit: true                         });                     });                     $("input[id$='Button1']").click(function(event) {                         $("#form1").validate({                             rules: {                                 txtName: { required: true }                                                             },                             messages: {}, onsubmit: true                         });                     });                 });                             </script>

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• Hidden web standards behind Google "custom searchEngines"?

  - by Hoàng Long

  Today while playing with Google Chrome Omnibox, I notice a strange behavior. I guess there's some "hidden" web standard behind it, but can't figure it out. Here's how to reproduce: Go to http://edition.cnn.com/ Use the search function at the higher right corner, Search a random keyword, for example: "abc" Close the tabs. Open a new tab, type until Chrome reminds you about http://edition.cnn.com/, then press "Tab" The Omnibox now shows "Search CNN.com"! And when you type "abc" and press Enter, it uses the CNN search function to do the job, not Google! I also tried it for several different sites. To some it won't work. But to some sites, like CNN, vnexpress.net, it works after I use the search function of that site once. I also learnt about chrome://settings/searchEngines (type it in your chrome box and you will see), and learnt about you can add custom search engine in chrome. But the question is, why Chrome can realize the search URL automatically to some pages, and not others? It's not because some site subscribe to Google service, because I can do the same method for my site (http://ledohoanglong.wordpress.com), and I'm sure that there's no subscription. So I guess there's a method to "expose" the search function of a site, so that Google Chrome can catch it (after I call the search function of that site once, of courses). Does anyone know about how it works behind the scene?

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• Why I'm getting the same result when deleting target?

  - by XNA

  In the following code we use target in the function: moon.mouseEnabled = false; sky0.addChild(moon); addEventListener(MouseEvent.MOUSE_DOWN, onDrag, false, 0, true); addEventListener(MouseEvent.MOUSE_UP, onDrop, false, 0, true); function onDrag(evt:MouseEvent):void { evt.target.addChild(moon); evt.target.startDrag(); } function onDrop(evt:MouseEvent):void { stopDrag(); } But if I rewrite this code without evt.target it still work. So what is the difference, am I going to get errors later in the run time because I didn't put target? If not then why some use target a lot while it works without it. function onDrag(evt:MouseEvent):void { addChild(moon); startDrag(); }

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• Recursion, Stacks and Queues

  An Article that hopes to Function as a Primer for Algorithms

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• Turn off the navigation menus on a MojoPortal page

  - by strongeye

  I needed to figure out how to turn off the navigation for the portal from my custom module. After some searching, I found code in Secure/Login.aspx.cs that did the trick. The function to use is this: SuppressAllMenus() This function is part of MojoPortal.Web.mojoBasePage so pages that inherit from that will already have access to the function.

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• Detecting HTML5/CSS3 Features using Modernizr

  - by dwahlin

  HTML5, CSS3, and related technologies such as canvas and web sockets bring a lot of useful new features to the table that can take Web applications to the next level. These new technologies allow applications to be built using only HTML, CSS, and JavaScript allowing them to be viewed on a variety of form factors including tablets and phones. Although HTML5 features offer a lot of promise, it’s not realistic to develop applications using the latest technologies without worrying about supporting older browsers in the process. If history has taught us anything it’s that old browsers stick around for years and years which means developers have to deal with backward compatibility issues. This is especially true when deploying applications to the Internet that target the general public. This begs the question, “How do you move forward with HTML5 and CSS3 technologies while gracefully handling unsupported features in older browsers?” Although you can write code by hand to detect different HTML5 and CSS3 features, it’s not always straightforward. For example, to check for canvas support you need to write code similar to the following:   <script> window.onload = function () { if (canvasSupported()) { alert('canvas supported'); } }; function canvasSupported() { var canvas = document.createElement('canvas'); return (canvas.getContext && canvas.getContext('2d')); } </script> If you want to check for local storage support the following check can be made. It’s more involved than it should be due to a bug in older versions of Firefox. <script> window.onload = function () { if (localStorageSupported()) { alert('local storage supported'); } }; function localStorageSupported() { try { return ('localStorage' in window && window['localStorage'] != null); } catch(e) {} return false; } </script> Looking through the previous examples you can see that there’s more than meets the eye when it comes to checking browsers for HTML5 and CSS3 features. It takes a lot of work to test every possible scenario and every version of a given browser. Fortunately, you don’t have to resort to writing custom code to test what HTML5/CSS3 features a given browser supports. By using a script library called Modernizr you can add checks for different HTML5/CSS3 features into your pages with a minimal amount of code on your part. Let’s take a look at some of the key features Modernizr offers.   Getting Started with Modernizr The first time I heard the name “Modernizr” I thought it “modernized” older browsers by added missing functionality. In reality, Modernizr doesn’t actually handle adding missing features or “modernizing” older browsers. The Modernizr website states, “The name Modernizr actually stems from the goal of modernizing our development practices (and ourselves)”. Because it relies on feature detection rather than browser sniffing (a common technique used in the past – that never worked that great), Modernizr definitely provides a more modern way to test features that a browser supports and can even handle loading additional scripts called shims or polyfills that fill in holes that older browsers may have. It’s a great tool to have in your arsenal if you’re a web developer. Modernizr is available at http://modernizr.com. Two different types of scripts are available including a development script and custom production script. To generate a production script, the site provides a custom script generation tool rather than providing a single script that has everything under the sun for HTML5/CSS3 feature detection. Using the script generation tool you can pick the specific test functionality that you need and ignore everything that you don’t need. That way the script is kept as small as possible. An example of the custom script download screen is shown next. Notice that specific CSS3, HTML5, and related feature tests can be selected. Once you’ve downloaded your custom script you can add it into your web page using the standard <script> element and you’re ready to start using Modernizr. <script src="Scripts/Modernizr.js" type="text/javascript"></script>   Modernizr and the HTML Element Once you’ve add a script reference to Modernizr in a page it’ll go to work for you immediately. In fact, by adding the script several different CSS classes will be added to the page’s <html> element at runtime. These classes define what features the browser supports and what features it doesn’t support. Features that aren’t supported get a class name of “no-FeatureName”, for example “no-flexbox”. Features that are supported get a CSS class name based on the feature such as “canvas” or “websockets”. An example of classes added when running a page in Chrome is shown next:   <html class=" js flexbox canvas canvastext webgl no-touch geolocation postmessage websqldatabase indexeddb hashchange history draganddrop websockets rgba hsla multiplebgs backgroundsize borderimage borderradius boxshadow textshadow opacity cssanimations csscolumns cssgradients cssreflections csstransforms csstransforms3d csstransitions fontface generatedcontent video audio localstorage sessionstorage webworkers applicationcache svg inlinesvg smil svgclippaths"> Here’s an example of what the <html> element looks like at runtime with Internet Explorer 9:   <html class=" js no-flexbox canvas canvastext no-webgl no-touch geolocation postmessage no-websqldatabase no-indexeddb hashchange no-history draganddrop no-websockets rgba hsla multiplebgs backgroundsize no-borderimage borderradius boxshadow no-textshadow opacity no-cssanimations no-csscolumns no-cssgradients no-cssreflections csstransforms no-csstransforms3d no-csstransitions fontface generatedcontent video audio localstorage sessionstorage no-webworkers no-applicationcache svg inlinesvg smil svgclippaths">   When using Modernizr it’s a common practice to define an <html> element in your page with a no-js class added as shown next:   <html class="no-js">   You’ll see starter projects such as HTML5 Boilerplate (http://html5boilerplate.com) or Initializr (http://initializr.com) follow this approach (see my previous post for more information on HTML5 Boilerplate). By adding the no-js class it’s easy to tell if a browser has JavaScript enabled or not. If JavaScript is disabled then no-js will stay on the <html> element. If JavaScript is enabled, no-js will be removed by Modernizr and a js class will be added along with other classes that define supported/unsupported features. Working with HTML5 and CSS3 Features You can use the CSS classes added to the <html> element directly in your CSS files to determine what style properties to use based upon the features supported by a given browser. For example, the following CSS can be used to render a box shadow for browsers that support that feature and a simple border for browsers that don’t support the feature: .boxshadow #MyContainer { border: none; -webkit-box-shadow: #666 1px 1px 1px; -moz-box-shadow: #666 1px 1px 1px; } .no-boxshadow #MyContainer { border: 2px solid black; }   If a browser supports box-shadows the boxshadow CSS class will be added to the <html> element by Modernizr. It can then be associated with a given element. This example associates the boxshadow class with a div with an id of MyContainer. If the browser doesn’t support box shadows then the no-boxshadow class will be added to the <html> element and it can be used to render a standard border around the div. This provides a great way to leverage new CSS3 features in supported browsers while providing a graceful fallback for older browsers. In addition to using the CSS classes that Modernizr provides on the <html> element, you also use a global Modernizr object that’s created. This object exposes different properties that can be used to detect the availability of specific HTML5 or CSS3 features. For example, the following code can be used to detect canvas and local storage support. You can see that the code is much simpler than the code shown at the beginning of this post. It also has the added benefit of being tested by a large community of web developers around the world running a variety of browsers.   $(document).ready(function () { if (Modernizr.canvas) { //Add canvas code } if (Modernizr.localstorage) { //Add local storage code } }); The global Modernizr object can also be used to test for the presence of CSS3 features. The following code shows how to test support for border-radius and CSS transforms:   $(document).ready(function () { if (Modernizr.borderradius) { $('#MyDiv').addClass('borderRadiusStyle'); } if (Modernizr.csstransforms) { $('#MyDiv').addClass('transformsStyle'); } });   Several other CSS3 feature tests can be performed such as support for opacity, rgba, text-shadow, CSS animations, CSS transitions, multiple backgrounds, and more. A complete list of supported HTML5 and CSS3 tests that Modernizr supports can be found at http://www.modernizr.com/docs.   Loading Scripts using Modernizr In cases where a browser doesn’t support a specific feature you can either provide a graceful fallback or load a shim/polyfill script to fill in missing functionality where appropriate (more information about shims/polyfills can be found at https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills). Modernizr has a built-in script loader that can be used to test for a feature and then load a script if the feature isn’t available. The script loader is built-into Modernizr and is also available as a standalone yepnope script (http://yepnopejs.com). It’s extremely easy to get started using the script loader and it can really simplify the process of loading scripts based on the availability of a particular browser feature. To load scripts dynamically you can use Modernizr’s load() function which accepts properties defining the feature to test (test property), the script to load if the test succeeds (yep property), the script to load if the test fails (nope property), and a script to load regardless of if the test succeeds or fails (both property). An example of using load() with these properties is show next: Modernizr.load({ test: Modernizr.canvas, yep: 'html5CanvasAvailable.js’, nope: 'excanvas.js’, both: 'myCustomScript.js' }); In this example Modernizr is used to not only load scripts but also to test for the presence of the canvas feature. If the target browser supports the HTML5 canvas then the html5CanvasAvailable.js script will be loaded along with the myCustomScript.js script (use of the yep property in this example is a bit contrived – it was added simply to demonstrate how the property can be used in the load() function). Otherwise, a polyfill script named excanvas.js will be loaded to add missing canvas functionality for Internet Explorer versions prior to 9. Once excanvas.js is loaded the myCustomScript.js script will be loaded. Because Modernizr handles loading scripts, you can also use it in creative ways. For example, you can use it to load local scripts when a 3rd party Content Delivery Network (CDN) such as one provided by Google or Microsoft is unavailable for whatever reason. The Modernizr documentation provides the following example that demonstrates the process for providing a local fallback for jQuery when a CDN is down:   Modernizr.load([ { load: '//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js', complete: function () { if (!window.jQuery) { Modernizr.load('js/libs/jquery-1.6.4.min.js'); } } }, { // This will wait for the fallback to load and // execute if it needs to. load: 'needs-jQuery.js' } ]); This code attempts to load jQuery from the Google CDN first. Once the script is downloaded (or if it fails) the function associated with complete will be called. The function checks to make sure that the jQuery object is available and if it’s not Modernizr is used to load a local jQuery script. After all of that occurs a script named needs-jQuery.js will be loaded. Conclusion If you’re building applications that use some of the latest and greatest features available in HTML5 and CSS3 then Modernizr is an essential tool. By using it you can reduce the amount of custom code required to test for browser features and provide graceful fallbacks or even load shim/polyfill scripts for older browsers to help fill in missing functionality. 

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• jQuery "Auto Post-back" Select/Drop-Down List

  - by Doug Lampe

  I have one common piece of jQuery code which I use to submit a form any time the selection changes on a drop-down list (HTML select tag).  This is similar to setting AutoPostBack = true in ASP.Net.  I use a single CSS class (autoSubmit) to annotate that I want the drop-down to force the form to submit on change so the HTML looks something like this: <select id="myAutoSubmitDropDown" name="myAutoSubmitDropDown" class="autoSubmit">     <option value="1">Option 1</option>     <option value="2">Option 2</option> </select> Then the following jQuery will look for any element with this CSS class and submit the parent form when the value is changed: function wireUpAutoSubmit() {   $(".autoSubmit").each(function (index) {     $(this).change(function () {       $(this).closest('form').submit();     })   }); } I put this in a separate function since I might need to wire this up explicitly after an ajax call.  Therefore I use the following code to set this method to fire when the DOM is loaded: $(document).ready(function () {   wireUpAutoSubmit(); });

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• SQL Server Cast

  - by Derek Dieter

  The SQL Server cast function is the easiest data type conversion function to be used compared to the CONVERT function. It takes only one parameter followed by the AS clause to convert a specified value. A quick example is the following:SELECT UserID_String = CAST(UserID AS varchar(50)) FROM dbo.UserThis example will convert the integer to a character value. [...]

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• Is my JS/Jquery methodology good?

  - by absentx

  I always struggle with which of the stack sites is best to post "questions of theory" like this, but I think programmers is the best, if not, as usual a mod will move it etc... I am seeking critique on what has become my normal methodology of writing javascript. I have become heavily reliant on the Jquery library, but I think this has helped me learn the native language better also. Anyways, please critique the following style of JS coding...buried are a lot of questions of scope, if you could point out the strengths and weaknesses of this style I would appreciate it. var critique ={ start: function(){ globalness = 'GLOBAL-GLOBAL'; //available to all critique's methods var notglobalness = 'LOCAL-LOCAL';// only available to critiques start method //am I using the "method" teminology properly here?? $('#stuff').on('click','a.closer-target',function(){ $target = $(this); if($target.hasClass('active')){ $target.removeClass('active'); } else{ $target.addClass('active'); critique.madness($target); } }) console.log(notglobalness+': at least I am useful at home'); console.log('note here that: '+notglobalness+' is no longer available after this point, lets continue on:'); critique.madness(notglobalness); }, madness: function($e){ // do a bunch of awesomeness with $e //but continue to keep it seperate because you think its best to keep things isolated. //send to the next function when complete here console.log('here is globalness, which is still available from the start method of critique!! ' + globalness); console.log('lets see if the globalness carries on to a new var object!!'); console.log('the locally isolated variable of NOTGLOBALNESS is available here because it was passed to this method, lets show it:'+$e); carryOn.start(); } } //end critique var carryOn={ start: function(){ console.log('any chance critique.globalness will work here??? lets see: ' +globalness); console.log('it absolutely does'); } } $(document).ready(critique.start);

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• How to select and deselect checkbox field into the GridView

  - by SAMIR BHOGAYTA

  //JavaScript function for Select and Deselect checkbox field in GridView function SelectDeselectAll(chkAll) { var a = document.forms[0]; var i=0; for(i=0;i lessthansign a.length;i++) { if(a[i].name.indexOf("chkItem") != -1) { a[i].checked = chkAll.checked; } } } function DeselectChkAll(chk) { var c=0; var d=1; var a = document.forms[0]; //alert(a.length); if(chk.checked == false) { document.getElementById("chkAll").checked = chk.checked; } else { for(i=0;i lessthansign a.length;i++) { if(a[i].name.indexOf("chkItem") != -1) { if(a[i].checked==true) { c=1; } else { d=0; } } } if(d != 0) { document.getElementById("chkAll").checked =true; } } } //How to use this function asp:TemplateField input id="Checkbox1" runat="server" onclick="javascript:SelectDeselectAll(this);" type="checkbox" / /HeaderTemplate /asp:GridView columns asp:TemplateFieldheadertemplate input id="chkAll" runat="server" onclick="javascript:SelectDeselectAll(this);" type="checkbox" / /HeaderTemplate

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• How do I check on non-transparent pixels in a bitmapdata?

  - by Opoe

  I'm still working on my window cleaning game from one of my previous questions I marked a contribution as my answer, but after all this time I can't get it to work and I have to many questions about this so I decided to ask some more about it. As a sequel on my mentioned previous question, my question to you is: How can I check whether or not a bitmapData contains non transparent pixels? Subquestion: Is this possible when the masked image is a movieclip? Shouldn't I use graphics instead? Information I have: A dirtywindow movieclip on the bottom layer and a clean window movieclip on layer 2(mc1) on the layer above. To hide the top layer(the dirty window) I assign a mask to it. Code // this creates a mask that hides the movieclip on top var mask_mc:MovieClip = new MovieClip(); addChild(mask_mc) //assign the mask to the movieclip it should 'cover' mc1.mask = mask_mc; With a brush(cursor) the player wipes of the dirt ( actualy setting the fill from the mask to transparent so the clean window appears) //add event listeners for the 'brush' brush_mc.addEventListener(MouseEvent.MOUSE_DOWN,brushDown); brush_mc.addEventListener(MouseEvent.MOUSE_UP,brushUp); //function to drag the brush over the mask function brushDown(dragging:MouseEvent):void{ dragging.currentTarget.startDrag(); MovieClip(dragging.currentTarget).addEventListener(Event.ENTER_FRAME,erase) ; mask_mc.graphics.moveTo(brush_mc.x,brush_mc.y); } //function to stop dragging the brush over the mask function brushUp(dragging:MouseEvent):void{ dragging.currentTarget.stopDrag(); MovieClip(dragging.currentTarget).removeEventListener(Event.ENTER_FRAME,erase); } //fill the mask with transparant pixels so the movieclip turns visible function erase(e:Event):void{ with(mask_mc.graphics){ beginFill(0x000000); drawRect(brush_mc.x,brush_mc.y,brush_mc.width,brush_mc.height); endFill(); } }

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• How to use correctly the comments in C/++

  - by Lucio

  I'm learning to program in C and in my stage, the best form to use correctly the comments is writing good comments from the beginning. As the comments are not just for that one understands better the code but others too, I want to know the views of all of you to reach a consensus. So what I want is that the most experienced users edit the following code as you please. (If it's unnecessary, delete it; If it's wrong, correct it; If needed, add more) Thus there'll be multiple answers with different syntax and the responses with the most votes will be taken as referring when commenting. The code to copy, paste and edit to your pleasure is: (And I remark again, just import the comments, not the code) /* This programs find 1 number in 1 file. The file is binary type and has integers in series. The number is integer type and it's entered from the keyboard. When finished the program, a poster will show the results: Saying if the number is in the file or not. */ #include <stdio.h> //FUNCTION 1 //Open file 'path' and closes it. void openf(char path[]) { int num; //Read from Keyboard a Number and it save it into 'num' var printf("Ready for read number.\n\nNumber --> "); fflush(stdin); scanf("%d",&num); //Open file 'path' in READ mode FILE *fvar; fvar=fopen(path,"rb"); //IF error happens when open file, exit of function if (fvar==NULL) { printf("ERROR while open file %s in read mode.",path); exit(1); } /*Verify the result of 'funct' function IF TRUE, 'num' it's in the file*/ if (funct(path,fvar,num)) printf("The number %d it is in the file %s.",num,path); else printf("The number %d it is not in the file %s.",num,path); fclose(fvar); } /*FUNCTION 2 It is a recursive function. Reads number by number until the file is empty or the number is found. Parameters received: 'path' -> Directory file 'fvar' -> Pointer file 'num' -> Number to compare */ int funct(char path[],FILE *fvar,int num) { int compare; //FALSE condition when the pointer reaches the end if (fread(&compare,sizeof(int),1,fvar)>0) /*TRUE condition when the number readed is iqual that 'num' ELSE will go to the function itself*/ if (compare!=num) funct(path,fvar,num); else return 1; else return 0; } int main(int argc, char **argv) { char path[30]="file.bin"; //Direction of the file to process openf(path); //Function with algorithm return 0; }

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• Disable pasting in a textbox using jQuery

  - by Michel Grootjans

  I had fun writing this one My current client asked me to allow users to paste text into textboxes/textareas, but that the pasted text should be cleaned from '<...>' tags. Here's what we came up with: $(":input").bind('paste', function(e) { var el = $(this); setTimeout(function() { var text = $(el).val(); $(el).val(text.replace(/<(.*?)>/gi, '')); }, 100); }) ; This is so simple, I'm amazed. The first part just binds a function to the paste operation applied to any input  declared on the page. $(":input").bind('paste', function(e) {...}); In the first line, I just capture the element. Then wait for 100ms setTimeout(function() {....}, 100); then get the actual value from the textbox, and replace it with a regular expression that basically means replace everything that looks like '<{0}>' with ''. gi at the end are regex arguments in javascript. /<(.*?)>/gi

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• Difference between IN and FIND_IN_SET

  - by Madhan ayyasamy

  Hi Friends,You may be confused with IN() and FIND_IN_SET() MYSQL functions. There are specific case/situation for both functions where to use which Mysql function. Look at below explanation about IN() and FIND_IN_SET()IN() : This function is used when you have a list of possible values and a single value in your database.Example: WHERE memberid IN (1,2,3)FIND_IN_SET() : This function is used where you have comma separated list of values stored in database and want to see if a certain value exists in that comma seperated list.Example: WHERE FIND_IN_SET( ‘table column name like id’, 'dynamic idlist' )

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• Was API hooking done as needed for Stuxnet to work? I don't think so

  - by The Kaykay

  Caveat: I am a political science student and I have tried my level best to understand the technicalities; if I still sound naive please overlook that. In the Symantec report on Stuxnet, the authors say that once the worm infects the 32-bit Windows computer which has a WINCC setup on it, Stuxnet does many things and that it specifically hooks the function CreateFileA(). This function is the route which the worm uses to actually infect the .s7p project files that are used to program the PLCs. ie when the PLC programmer opens a file with .s7p the control transfers to the hooked function CreateFileA_hook() instead of CreateFileA(). Once Stuxnet gains the control it covertly inserts code blocks into the PLC without the programmers knowledge and hides it from his view. However, it should be noted that there is also one more function called CreateFileW() which does the same task as CreateFileA() but both work on different character sets. CreateFileA works with ASCII character set and CreateFileW works with wide characters or Unicode character set. Farsi (the language of the Iranians) is a language that needs unicode character set and not ASCII Characters. I'm assuming that the developers of any famous commercial software (for ex. WinCC) that will be sold in many countries will take 'Localization' and/or 'Internationalization' into consideration while it is being developed in order to make the product fail-safe ie. the software developers would use UNICODE while compiling their code and not just 'ASCII'. Thus, I think that CreateFileW() would have been invoked on a WINCC system in Iran instead of CreateFileA(). Do you agree? My question is: If Stuxnet has hooked only the function CreateFileA() then based on the above assumption there is a significant chance that it did not work at all? I think my doubt will get clarified if: my assumption is proved wrong, or the Symantec report is proved incorrect. Please help me clarify this doubt. Note: I had posted this question on the general stackexchange website and did not get appropriate responses that I was looking for so I'm posting it here.

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• HTML Canvas: Should my app x, y values be global?

  - by Joe

  I have a large file of functions. Each of these functions is responsible for drawing a particular part of the application. My app has x and y parameters that I use in the setup function to move the whole app around in order to try different placements. So, naturally, I need to use these x and y values to anchor each function's component rendering so that everything moves in unison if the global x,y values ever change. My question is, is it bad practice/architecture to have these x,y values in the global namespace and having the each function directly access them like so? function renderFace() { var x = App.x; var y = App.y; // drawing here } is there a better way i'm missing?

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• JSCompress fails to compress my js file - why?

  - by Renso

  Issue: You use the online compression utility jscompress.com to compress your js file but it fails with an error. Why this may be happening and how to fix it. Possible causes: Apparently not using open and closing curly brackets in an IF statement would cause this. Well turns out this is not the case. Look at the following example and see if you can figure out what the issue is :-)   function SetupDeliveredVPRecontactNotes($item, id) {     var theData;     $.ajax({         data: { deliveredVPId: id },         url: $('#ajaxGetDeliveredVPRecontactNotesUrl').val(),         type: "GET",         async: false,         dataType: "html",         success: function(data, result) {             $item.empty();             var input = '<textarea class="recontactNote" rows="4" name="DeliveredVPRecontactNotes_' + id + '" id="DeliveredVPRecontactNotes_' + id + '" cols="115">' + data + '</textarea>';             $item.append(input);             theData = data;         },         error: function(XMLHttpRequest, textStatus, errorThrown) {             $item.empty();             alert("An error occurred: The operation to retrieve the DeliveredVP's Recontact Notes has failed");         }     });                  //ajax     return theData; }     Solution: The name of the method/function is the same as the message in the ALERT message when the spaces are removed: " DeliveredVP Recontact Notes" becomes " DeliveredVPRecontactNotes" and mathes that of the function. So I changed it to " DeliveredVP's Recontact Notes"

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• What is wrong with my game loop/mechanic?

  - by elias94xx

  I'm currently working on a 2d sidescrolling game prototype in HTML5 canvas. My implementations so far include a sprite, vector, loop and ticker class/object. Which can be viewed here: http://elias-schuett.de/apps/_experiments/2d_ssg/js/ So my game essentially works well on todays lowspec PC's and laptops. But it does not on an older win xp machine I own and on my Android 2.3 device. I tend to get ~10 FPS with these devices which results in a too high delta value, which than automaticly gets fixed to 1.0 which results in a slow loop. Now I know for a fact that there is a way to implement a super smooth 60 or 30 FPS loop on both devices. Best example would be: http://playbiolab.com/ I don't need all the chunk and debugging technology impact.js offers. I could even write a super simple game where you just control a damn square and it still wouldn't run on a equally fast 30 or 60 fps. Here is the Loop class/object I'm using. It requires a requestAnimationFrame unify function. Both devices I've tested my game on support requestAnimationFrame, so there is no interval fallback. var Loop = function(callback) { this.fps = null; this.delta = 1; this.lastTime = +new Date; this.callback = callback; this.request = null; }; Loop.prototype.start = function() { var _this = this; this.request = requestAnimationFrame(function(now) { _this.start(); _this.delta = (now - _this.lastTime); _this.fps = 1000/_this.delta; _this.delta = _this.delta / (1000/60) > 2 ? 1 : _this.delta / (1000/60); _this.lastTime = now; _this.callback(); }); }; Loop.prototype.stop = function() { cancelAnimationFrame(this.request); };

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• Unrealscript splitting a string

  - by burntsugar

  Note, this is repost from stackoverflow - I have only just discovered this site :) I need to split a string in Unrealscript, in the same way that Java's split function works. For instance - return the string "foo" as an array of char. I have tried to use the SplitString function: array SplitString( string Source, optional string Delimiter=",", optional bool bCullEmpty ) Wrapper for splitting a string into an array of strings using a single expression. as found at http://udn.epicgames.com/Three/UnrealScriptFunctions.html but it returns the entire String. simulated function wordDraw() { local String inputString; inputString = "trolls"; local string whatwillitbe; local int b; local int x; local array<String> letterArray; letterArray = SplitString(inputString,, false); for (x = 0; x < letterArray.Length; x++) { whatwillitbe = letterArray[x]; `log('it will be '@whatwillitbe); b = letterarray.Length; `log('letterarray length is '@b); `log('letter number '@x); } } Output is: b returns: 1 whatwillitbe returns: trolls However I would like b to return 6 and whatwillitbe to return each character individually. I have had a few answers proposed, however, I would still like to properly understand how the SplitString function works. For instance, if the Delimiter parameter is optional, what does the function use as a delimiter by default?

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• jrunscript as a cross platform scripting environment

  - by user12798506

  ?????????????????????????????????????????????????????????sh????????????UNIX???????????????????sh???????????????????????????????????????????Windows????????????????? sh??????????????find?grep?sed?awk???Windows??????????????????????????????????????????????????????????????????????????????????????????????Windows???Cygwin????????????sh??????Windows??????????????Cygwin????????????????????????????????????????????JDK?????jrunscript?????JavaScript???????????????????????1?????????jrunscript??????????????????? Windows???UNIX??????????????????????? find?grep?sed?awk?????????sh???????????????Windows Script Host??????? Java????????????? ??????????????????????????????????????????????????????????(?????????????????????????????????????????) ?????????????JDK 6??????????????????????????PC????????????????JDK 6?PC????????????????????????????????????JDK????????????????????????????????????????jrunscript?????????????????????????? ?????jrunscript????JavaScript?????????????????????????????????????????? 1) Windows???UNIX????????????????? ?????????????????????????????????????????JavaScript???mytool.js???????????????????????jrunscript???????????UNIX????sh???????Windows????bat????????????????????? mytool.sh (UNIX?): #!/bin/sh bindir=$(cd $(dirname $0) && pwd) case "`uname`" in CYGWIN*) bindir=`cygpath -w "$bindir"` ;; esac jrunscript "${bindir}/mytool.js" $* mytool.bat (Windows?): @echo off set bindir=%~dp0 jrunscript "%bindir%mytool.js" %* UNIX??sh????????Cygwin???????????????????????????????????????????js??????????????UNIX?Windows??????????????????????????????? 2) jrunscript??cat, cp, find?grep?????? jrunscript???UNIX?????????????????????????????????? jrunscript JavaScript built-in functions ????UNIX??sh?????????????????????UNIX?????????????????????????????????????????src??????????java????????????enum???????java?????????????????????????????????????????????? find('src', '.*.java', function(f) { grep('enum', f); }); ???????UNIX?????????????????????????????????????????????????????????????????????????????????????????cp(from, to)??????????????????????????????????????????UNIX??????????? $ cp -r src/* tmp/ ?????????????????????????????????????????find()???????cp -r????????·?????????????????????? function cpr(fromdir, todir, pattern) { if (pattern == undefined) { pattern = ".*"; } var frdir = pathToFile(fromdir).getCanonicalPath(); find(fromdir, pattern, function(f) { // relative dir of file f from 'fromdir'. var relative = f.getParentFile().getCanonicalPath().substring(frdir.length() + 1); var dstdir = pathToFile(todir + "/" + relative); if (!dstdir.exists()) { // Create the destination dir for file f. mkdirs(dstdir); } // Copy file f to 'dstdir'. cp(f, dstdir + "/" + f.getName()); }); } java?????I/O?API??Windows?????????????"/"??????????????????????????????UNIX?Windows?????????????? ????????????exec(cmd)?????????jar???????????????????????????????????????????? $ jrunscript js> exec("jar xvf example.jar") META-INF/ ?????????????µ???B META-INF/MANIFEST.MF ???W?J???????µ???B com/ ?????????????µ???B com/example/ ?????????????µ???B com/example/Bar.class ???W?J???????µ???B com/example/dummy/ ?????????????µ???B com/example/dummy/dummy.txt ?????o???????µ???B com/example/dummy.properties ?????o???????µ???B com/example/Foo.class ???W?J???????µ???B ???exec()?????????????????????????????????????????????????????????????????Windows????????????I/O??????????????????????????????????BAT????????? errmsg.bat: for /L %%i in (1,1,50) do echo "Error Message count = %%i" 1&2 jrunscript??exec()???????????????18??????????????????????????????????? C:\tmp>jrunscript -e "exec('errmsg.bat')" C:\tmp>for /L %i in (1 1 100) do echo "Error Message count = %i" 1>&2 C:\tmp>echo "Error Message count = 1" 1>&2 : C:\tmp>echo "Error Message count = 18" 1>&2 ? ??? ???????????exec()?????????????????????????????????????????????????????????????????DataInputStream???????????????????????? $ jrunscript js this["exec"].toString() function exec(cmd) { var process = java.lang.Runtime.getRuntime().exec(cmd); var inp = new DataInputStream(process.getInputStream()); var line = null; while ((line = inp.readLine()) != null) { println(line); } process.waitFor(); $exit = process.exitValue(); } ?????????????????????????????????????????????????????exec()???????????????exec()?????????????????????????????exec()??????? function exec(cmd) { var process = java.lang.Runtime.getRuntime().exec(cmd); var stdworker = new java.lang.Runnable( {run: function() { cat(process.getInputStream()); }}); var errworker = new java.lang.Runnable( {run: function() { cat(process.getErrorStream()); }}); new java.lang.Thread(stdworker).start(); new java.lang.Thread(errworker).start(); return proc.waitFor(); } ???????????????????cat()???????????cat()?InputStreamReader?????????????????????????????????????????????????? 3) JavaScript???????????????? JavaScript?Java???????????????????????JavaScript????????????Ruby?Groovy?Scala???????????????????????????????????????????????10MB?????????????????????????????????????JavaScript????????????????????KB?????????????MB?JAR??????????????????????????JRE?JDK?????????????????????????????????????????

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• A good way to build a game loop in OpenGL

  - by Jeff

  I'm currently beginning to learn OpenGL at school, and I've started making a simple game the other day (on my own, not for school). I'm using freeglut, and am building it in C, so for my game loop I had really just been using a function I made passed to glutIdleFunc to update all the drawing and physics in one pass. This was fine for simple animations that I didn't care too much about the frame rate, but since the game is mostly physics based, I really want to (need to) tie down how fast it's updating. So my first attempt was to have my function I pass to glutIdleFunc (myIdle()) to keep track of how much time has passed since the previous call to it, and update the physics (and currently graphics) every so many milliseconds. I used timeGetTime() to do this (by using <windows.h>). And this got me to thinking, is using the idle function really a good way of going about the game loop? My question is, what is a better way to implement the game loop in OpenGL? Should I avoid using the idle function?

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• Using R to Analyze G1GC Log Files

  - by user12620111

  Using R to Analyze G1GC Log Files body, td { font-family: sans-serif; background-color: white; font-size: 12px; margin: 8px; } tt, code, pre { font-family: 'DejaVu Sans Mono', 'Droid Sans Mono', 'Lucida Console', Consolas, Monaco, monospace; } h1 { font-size:2.2em; } h2 { font-size:1.8em; } h3 { font-size:1.4em; } h4 { font-size:1.0em; } h5 { font-size:0.9em; } h6 { font-size:0.8em; } a:visited { color: rgb(50%, 0%, 50%); } pre { margin-top: 0; max-width: 95%; border: 1px solid #ccc; white-space: pre-wrap; } pre code { display: block; padding: 0.5em; } code.r, code.cpp { background-color: #F8F8F8; } table, td, th { border: none; } blockquote { color:#666666; margin:0; padding-left: 1em; border-left: 0.5em #EEE solid; } hr { height: 0px; border-bottom: none; border-top-width: thin; border-top-style: dotted; border-top-color: #999999; } @media print { * { background: transparent !important; color: black !important; filter:none !important; -ms-filter: none !important; } body { 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  Using R to Analyze G1GC Log Files   Using R to Analyze G1GC Log Files Introduction Working in Oracle Platform Integration gives an engineer opportunities to work on a wide array of technologies. My team’s goal is to make Oracle applications run best on the Solaris/SPARC platform. When looking for bottlenecks in a modern applications, one needs to be aware of not only how the CPUs and operating system are executing, but also network, storage, and in some cases, the Java Virtual Machine. I was recently presented with about 1.5 GB of Java Garbage First Garbage Collector log file data. If you’re not familiar with the subject, you might want to review Garbage First Garbage Collector Tuning by Monica Beckwith. The customer had been running Java HotSpot 1.6.0_31 to host a web application server. I was told that the Solaris/SPARC server was running a Java process launched using a commmand line that included the following flags: -d64 -Xms9g -Xmx9g -XX:+UseG1GC -XX:MaxGCPauseMillis=200 -XX:InitiatingHeapOccupancyPercent=80 -XX:PermSize=256m -XX:MaxPermSize=256m -XX:+PrintGC -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC -XX:+PrintGCDateStamps -XX:+PrintFlagsFinal -XX:+DisableExplicitGC -XX:+UnlockExperimentalVMOptions -XX:ParallelGCThreads=8 Several sources on the internet indicate that if I were to print out the 1.5 GB of log files, it would require enough paper to fill the bed of a pick up truck. Of course, it would be fruitless to try to scan the log files by hand. Tools will be required to summarize the contents of the log files. Others have encountered large Java garbage collection log files. There are existing tools to analyze the log files: IBM’s GC toolkit The chewiebug GCViewer gchisto HPjmeter Instead of using one of the other tools listed, I decide to parse the log files with standard Unix tools, and analyze the data with R. Data Cleansing The log files arrived in two different formats. I guess that the difference is that one set of log files was generated using a more verbose option, maybe -XX:+PrintHeapAtGC, and the other set of log files was generated without that option. Format 1 In some of the log files, the log files with the less verbose format, a single trace, i.e. the report of a singe garbage collection event, looks like this: {Heap before GC invocations=12280 (full 61): garbage-first heap total 9437184K, used 7499918K [0xfffffffd00000000, 0xffffffff40000000, 0xffffffff40000000) region size 4096K, 1 young (4096K), 0 survivors (0K) compacting perm gen total 262144K, used 144077K [0xffffffff40000000, 0xffffffff50000000, 0xffffffff50000000) the space 262144K, 54% used [0xffffffff40000000, 0xffffffff48cb3758, 0xffffffff48cb3800, 0xffffffff50000000) No shared spaces configured. 2014-05-14T07:24:00.988-0700: 60586.353: [GC pause (young) 7324M->7320M(9216M), 0.1567265 secs] Heap after GC invocations=12281 (full 61): garbage-first heap total 9437184K, used 7496533K [0xfffffffd00000000, 0xffffffff40000000, 0xffffffff40000000) region size 4096K, 0 young (0K), 0 survivors (0K) compacting perm gen total 262144K, used 144077K [0xffffffff40000000, 0xffffffff50000000, 0xffffffff50000000) the space 262144K, 54% used [0xffffffff40000000, 0xffffffff48cb3758, 0xffffffff48cb3800, 0xffffffff50000000) No shared spaces configured. } A simple grep can be used to extract a summary: $ grep "\[ GC pause (young" g1gc.log 2014-05-13T13:24:35.091-0700: 3.109: [GC pause (young) 20M->5029K(9216M), 0.0146328 secs] 2014-05-13T13:24:35.440-0700: 3.459: [GC pause (young) 9125K->6077K(9216M), 0.0086723 secs] 2014-05-13T13:24:37.581-0700: 5.599: [GC pause (young) 25M->8470K(9216M), 0.0203820 secs] 2014-05-13T13:24:42.686-0700: 10.704: [GC pause (young) 44M->15M(9216M), 0.0288848 secs] 2014-05-13T13:24:48.941-0700: 16.958: [GC pause (young) 51M->20M(9216M), 0.0491244 secs] 2014-05-13T13:24:56.049-0700: 24.066: [GC pause (young) 92M->26M(9216M), 0.0525368 secs] 2014-05-13T13:25:34.368-0700: 62.383: [GC pause (young) 602M->68M(9216M), 0.1721173 secs] But that format wasn't easily read into R, so I needed to be a bit more tricky. I used the following Unix command to create a summary file that was easy for R to read. $ echo "SecondsSinceLaunch BeforeSize AfterSize TotalSize RealTime" $ grep "\[GC pause (young" g1gc.log | grep -v mark | sed -e 's/[A-SU-z\(\),]/ /g' -e 's/->/ /' -e 's/: / /g' | more SecondsSinceLaunch BeforeSize AfterSize TotalSize RealTime 2014-05-13T13:24:35.091-0700 3.109 20 5029 9216 0.0146328 2014-05-13T13:24:35.440-0700 3.459 9125 6077 9216 0.0086723 2014-05-13T13:24:37.581-0700 5.599 25 8470 9216 0.0203820 2014-05-13T13:24:42.686-0700 10.704 44 15 9216 0.0288848 2014-05-13T13:24:48.941-0700 16.958 51 20 9216 0.0491244 2014-05-13T13:24:56.049-0700 24.066 92 26 9216 0.0525368 2014-05-13T13:25:34.368-0700 62.383 602 68 9216 0.1721173 Format 2 In some of the log files, the log files with the more verbose format, a single trace, i.e. the report of a singe garbage collection event, was more complicated than Format 1. Here is a text file with an example of a single G1GC trace in the second format. As you can see, it is quite complicated. It is nice that there is so much information available, but the level of detail can be overwhelming. I wrote this awk script (download) to summarize each trace on a single line. #!/usr/bin/env awk -f BEGIN { printf("SecondsSinceLaunch IncrementalCount FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize\n") } ###################### # Save count data from lines that are at the start of each G1GC trace. # Each trace starts out like this: # {Heap before GC invocations=14 (full 0): # garbage-first heap total 9437184K, used 325496K [0xfffffffd00000000, 0xffffffff40000000, 0xffffffff40000000) ###################### /{Heap.*full/{ gsub ( "\\)" , "" ); nf=split($0,a,"="); split(a[2],b," "); getline; if ( match($0, "first") ) { G1GC=1; IncrementalCount=b[1]; FullCount=substr( b[3], 1, length(b[3])-1 ); } else { G1GC=0; } } ###################### # Pull out time stamps that are in lines with this format: # 2014-05-12T14:02:06.025-0700: 94.312: [GC pause (young), 0.08870154 secs] ###################### /GC pause/ { DateTime=$1; SecondsSinceLaunch=substr($2, 1, length($2)-1); } ###################### # Heap sizes are in lines that look like this: # [ 4842M->4838M(9216M)] ###################### /\[ .*]$/ { gsub ( "\\[" , "" ); gsub ( "\ \]" , "" ); gsub ( "->" , " " ); gsub ( "\\( " , " " ); gsub ( "\ \)" , " " ); split($0,a," "); if ( split(a[1],b,"M") > 1 ) {BeforeSize=b[1]*1024;} if ( split(a[1],b,"K") > 1 ) {BeforeSize=b[1];} if ( split(a[2],b,"M") > 1 ) {AfterSize=b[1]*1024;} if ( split(a[2],b,"K") > 1 ) {AfterSize=b[1];} if ( split(a[3],b,"M") > 1 ) {TotalSize=b[1]*1024;} if ( split(a[3],b,"K") > 1 ) {TotalSize=b[1];} } ###################### # Emit an output line when you find input that looks like this: # [Times: user=1.41 sys=0.08, real=0.24 secs] ###################### /\[Times/ { if (G1GC==1) { gsub ( "," , "" ); split($2,a,"="); UserTime=a[2]; split($3,a,"="); SysTime=a[2]; split($4,a,"="); RealTime=a[2]; print DateTime,SecondsSinceLaunch,IncrementalCount,FullCount,UserTime,SysTime,RealTime,BeforeSize,AfterSize,TotalSize; G1GC=0; } } The resulting summary is about 25X smaller that the original file, but still difficult for a human to digest. SecondsSinceLaunch IncrementalCount FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize ... 2014-05-12T18:36:34.669-0700: 3985.744 561 0 0.57 0.06 0.16 1724416 1720320 9437184 2014-05-12T18:36:34.839-0700: 3985.914 562 0 0.51 0.06 0.19 1724416 1720320 9437184 2014-05-12T18:36:35.069-0700: 3986.144 563 0 0.60 0.04 0.27 1724416 1721344 9437184 2014-05-12T18:36:35.354-0700: 3986.429 564 0 0.33 0.04 0.09 1725440 1722368 9437184 2014-05-12T18:36:35.545-0700: 3986.620 565 0 0.58 0.04 0.17 1726464 1722368 9437184 2014-05-12T18:36:35.726-0700: 3986.801 566 0 0.43 0.05 0.12 1726464 1722368 9437184 2014-05-12T18:36:35.856-0700: 3986.930 567 0 0.30 0.04 0.07 1726464 1723392 9437184 2014-05-12T18:36:35.947-0700: 3987.023 568 0 0.61 0.04 0.26 1727488 1723392 9437184 2014-05-12T18:36:36.228-0700: 3987.302 569 0 0.46 0.04 0.16 1731584 1724416 9437184 Reading the Data into R Once the GC log data had been cleansed, either by processing the first format with the shell script, or by processing the second format with the awk script, it was easy to read the data into R. g1gc.df = read.csv("summary.txt", row.names = NULL, stringsAsFactors=FALSE,sep="") str(g1gc.df) ## 'data.frame': 8307 obs. of 10 variables: ## $ row.names : chr "2014-05-12T14:00:32.868-0700:" "2014-05-12T14:00:33.179-0700:" "2014-05-12T14:00:33.677-0700:" "2014-05-12T14:00:35.538-0700:" ... ## $ SecondsSinceLaunch: num 1.16 1.47 1.97 3.83 6.1 ... ## $ IncrementalCount : int 0 1 2 3 4 5 6 7 8 9 ... ## $ FullCount : int 0 0 0 0 0 0 0 0 0 0 ... ## $ UserTime : num 0.11 0.05 0.04 0.21 0.08 0.26 0.31 0.33 0.34 0.56 ... ## $ SysTime : num 0.04 0.01 0.01 0.05 0.01 0.06 0.07 0.06 0.07 0.09 ... ## $ RealTime : num 0.02 0.02 0.01 0.04 0.02 0.04 0.05 0.04 0.04 0.06 ... ## $ BeforeSize : int 8192 5496 5768 22528 24576 43008 34816 53248 55296 93184 ... ## $ AfterSize : int 1400 1672 2557 4907 7072 14336 16384 18432 19456 21504 ... ## $ TotalSize : int 9437184 9437184 9437184 9437184 9437184 9437184 9437184 9437184 9437184 9437184 ... head(g1gc.df) ## row.names SecondsSinceLaunch IncrementalCount ## 1 2014-05-12T14:00:32.868-0700: 1.161 0 ## 2 2014-05-12T14:00:33.179-0700: 1.472 1 ## 3 2014-05-12T14:00:33.677-0700: 1.969 2 ## 4 2014-05-12T14:00:35.538-0700: 3.830 3 ## 5 2014-05-12T14:00:37.811-0700: 6.103 4 ## 6 2014-05-12T14:00:41.428-0700: 9.720 5 ## FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize ## 1 0 0.11 0.04 0.02 8192 1400 9437184 ## 2 0 0.05 0.01 0.02 5496 1672 9437184 ## 3 0 0.04 0.01 0.01 5768 2557 9437184 ## 4 0 0.21 0.05 0.04 22528 4907 9437184 ## 5 0 0.08 0.01 0.02 24576 7072 9437184 ## 6 0 0.26 0.06 0.04 43008 14336 9437184 Basic Statistics Once the data has been read into R, simple statistics are very easy to generate. All of the numbers from high school statistics are available via simple commands. For example, generate a summary of every column: summary(g1gc.df) ## row.names SecondsSinceLaunch IncrementalCount FullCount ## Length:8307 Min. : 1 Min. : 0 Min. : 0.0 ## Class :character 1st Qu.: 9977 1st Qu.:2048 1st Qu.: 0.0 ## Mode :character Median :12855 Median :4136 Median : 12.0 ## Mean :12527 Mean :4156 Mean : 31.6 ## 3rd Qu.:15758 3rd Qu.:6262 3rd Qu.: 61.0 ## Max. :55484 Max. :8391 Max. :113.0 ## UserTime SysTime RealTime BeforeSize ## Min. :0.040 Min. :0.0000 Min. : 0.0 Min. : 5476 ## 1st Qu.:0.470 1st Qu.:0.0300 1st Qu.: 0.1 1st Qu.:5137920 ## Median :0.620 Median :0.0300 Median : 0.1 Median :6574080 ## Mean :0.751 Mean :0.0355 Mean : 0.3 Mean :5841855 ## 3rd Qu.:0.920 3rd Qu.:0.0400 3rd Qu.: 0.2 3rd Qu.:7084032 ## Max. :3.370 Max. :1.5600 Max. :488.1 Max. :8696832 ## AfterSize TotalSize ## Min. : 1380 Min. :9437184 ## 1st Qu.:5002752 1st Qu.:9437184 ## Median :6559744 Median :9437184 ## Mean :5785454 Mean :9437184 ## 3rd Qu.:7054336 3rd Qu.:9437184 ## Max. :8482816 Max. :9437184 Q: What is the total amount of User CPU time spent in garbage collection? sum(g1gc.df$UserTime) ## [1] 6236 As you can see, less than two hours of CPU time was spent in garbage collection. Is that too much? To find the percentage of time spent in garbage collection, divide the number above by total_elapsed_time*CPU_count. In this case, there are a lot of CPU’s and it turns out the the overall amount of CPU time spent in garbage collection isn’t a problem when viewed in isolation. When calculating rates, i.e. events per unit time, you need to ask yourself if the rate is homogenous across the time period in the log file. Does the log file include spikes of high activity that should be separately analyzed? Averaging in data from nights and weekends with data from business hours may alias problems. If you have a reason to suspect that the garbage collection rates include peaks and valleys that need independent analysis, see the “Time Series” section, below. Q: How much garbage is collected on each pass? The amount of heap space that is recovered per GC pass is surprisingly low: At least one collection didn’t recover any data. (“Min.=0”) 25% of the passes recovered 3MB or less. (“1st Qu.=3072”) Half of the GC passes recovered 4MB or less. (“Median=4096”) The average amount recovered was 56MB. (“Mean=56390”) 75% of the passes recovered 36MB or less. (“3rd Qu.=36860”) At least one pass recovered 2GB. (“Max.=2121000”) g1gc.df$Delta = g1gc.df$BeforeSize - g1gc.df$AfterSize summary(g1gc.df$Delta) ## Min. 1st Qu. Median Mean 3rd Qu. Max. ## 0 3070 4100 56400 36900 2120000 Q: What is the maximum User CPU time for a single collection? The worst garbage collection (“Max.”) is many standard deviations away from the mean. The data appears to be right skewed. summary(g1gc.df$UserTime) ## Min. 1st Qu. Median Mean 3rd Qu. Max. ## 0.040 0.470 0.620 0.751 0.920 3.370 sd(g1gc.df$UserTime) ## [1] 0.3966 Basic Graphics Once the data is in R, it is trivial to plot the data with formats including dot plots, line charts, bar charts (simple, stacked, grouped), pie charts, boxplots, scatter plots histograms, and kernel density plots. Histogram of User CPU Time per Collection I don't think that this graph requires any explanation. hist(g1gc.df$UserTime, main="User CPU Time per Collection", xlab="Seconds", ylab="Frequency") Box plot to identify outliers When the initial data is viewed with a box plot, you can see the one crazy outlier in the real time per GC. Save this data point for future analysis and drop the outlier so that it’s not throwing off our statistics. Now the box plot shows many outliers, which will be examined later, using times series analysis. Notice that the scale of the x-axis changes drastically once the crazy outlier is removed. par(mfrow=c(2,1)) boxplot(g1gc.df$UserTime,g1gc.df$SysTime,g1gc.df$RealTime, main="Box Plot of Time per GC\n(dominated by a crazy outlier)", names=c("usr","sys","elapsed"), xlab="Seconds per GC", ylab="Time (Seconds)", horizontal = TRUE, outcol="red") crazy.outlier.df=g1gc.df[g1gc.df$RealTime > 400,] g1gc.df=g1gc.df[g1gc.df$RealTime < 400,] boxplot(g1gc.df$UserTime,g1gc.df$SysTime,g1gc.df$RealTime, main="Box Plot of Time per GC\n(crazy outlier excluded)", names=c("usr","sys","elapsed"), xlab="Seconds per GC", ylab="Time (Seconds)", horizontal = TRUE, outcol="red") box(which = "outer", lty = "solid") Here is the crazy outlier for future analysis: crazy.outlier.df ## row.names SecondsSinceLaunch IncrementalCount ## 8233 2014-05-12T23:15:43.903-0700: 20741 8316 ## FullCount UserTime SysTime RealTime BeforeSize AfterSize TotalSize ## 8233 112 0.55 0.42 488.1 8381440 8235008 9437184 ## Delta ## 8233 146432 R Time Series Data To analyze the garbage collection as a time series, I’ll use Z’s Ordered Observations (zoo). “zoo is the creator for an S3 class of indexed totally ordered observations which includes irregular time series.” require(zoo) ## Loading required package: zoo ## ## Attaching package: 'zoo' ## ## The following objects are masked from 'package:base': ## ## as.Date, as.Date.numeric head(g1gc.df[,1]) ## [1] "2014-05-12T14:00:32.868-0700:" "2014-05-12T14:00:33.179-0700:" ## [3] "2014-05-12T14:00:33.677-0700:" "2014-05-12T14:00:35.538-0700:" ## [5] "2014-05-12T14:00:37.811-0700:" "2014-05-12T14:00:41.428-0700:" options("digits.secs"=3) times=as.POSIXct( g1gc.df[,1], format="%Y-%m-%dT%H:%M:%OS%z:") g1gc.z = zoo(g1gc.df[,-c(1)], order.by=times) head(g1gc.z) ## SecondsSinceLaunch IncrementalCount FullCount ## 2014-05-12 17:00:32.868 1.161 0 0 ## 2014-05-12 17:00:33.178 1.472 1 0 ## 2014-05-12 17:00:33.677 1.969 2 0 ## 2014-05-12 17:00:35.538 3.830 3 0 ## 2014-05-12 17:00:37.811 6.103 4 0 ## 2014-05-12 17:00:41.427 9.720 5 0 ## UserTime SysTime RealTime BeforeSize AfterSize ## 2014-05-12 17:00:32.868 0.11 0.04 0.02 8192 1400 ## 2014-05-12 17:00:33.178 0.05 0.01 0.02 5496 1672 ## 2014-05-12 17:00:33.677 0.04 0.01 0.01 5768 2557 ## 2014-05-12 17:00:35.538 0.21 0.05 0.04 22528 4907 ## 2014-05-12 17:00:37.811 0.08 0.01 0.02 24576 7072 ## 2014-05-12 17:00:41.427 0.26 0.06 0.04 43008 14336 ## TotalSize Delta ## 2014-05-12 17:00:32.868 9437184 6792 ## 2014-05-12 17:00:33.178 9437184 3824 ## 2014-05-12 17:00:33.677 9437184 3211 ## 2014-05-12 17:00:35.538 9437184 17621 ## 2014-05-12 17:00:37.811 9437184 17504 ## 2014-05-12 17:00:41.427 9437184 28672 Example of Two Benchmark Runs in One Log File The data in the following graph is from a different log file, not the one of primary interest to this article. I’m including this image because it is an example of idle periods followed by busy periods. It would be uninteresting to average the rate of garbage collection over the entire log file period. More interesting would be the rate of garbage collect in the two busy periods. Are they the same or different? Your production data may be similar, for example, bursts when employees return from lunch and idle times on weekend evenings, etc. Once the data is in an R Time Series, you can analyze isolated time windows. Clipping the Time Series data Flashing back to our test case… Viewing the data as a time series is interesting. You can see that the work intensive time period is between 9:00 PM and 3:00 AM. Lets clip the data to the interesting period:     par(mfrow=c(2,1)) plot(g1gc.z$UserTime, type="h", main="User Time per GC\nTime: Complete Log File", xlab="Time of Day", ylab="CPU Seconds per GC", col="#1b9e77") clipped.g1gc.z=window(g1gc.z, start=as.POSIXct("2014-05-12 21:00:00"), end=as.POSIXct("2014-05-13 03:00:00")) plot(clipped.g1gc.z$UserTime, type="h", main="User Time per GC\nTime: Limited to Benchmark Execution", xlab="Time of Day", ylab="CPU Seconds per GC", col="#1b9e77") box(which = "outer", lty = "solid") Cumulative Incremental and Full GC count Here is the cumulative incremental and full GC count. When the line is very steep, it indicates that the GCs are repeating very quickly. Notice that the scale on the Y axis is different for full vs. incremental. plot(clipped.g1gc.z[,c(2:3)], main="Cumulative Incremental and Full GC count", xlab="Time of Day", col="#1b9e77") GC Analysis of Benchmark Execution using Time Series data In the following series of 3 graphs: The “After Size” show the amount of heap space in use after each garbage collection. Many Java objects are still referenced, i.e. alive, during each garbage collection. This may indicate that the application has a memory leak, or may indicate that the application has a very large memory footprint. Typically, an application's memory footprint plateau's in the early stage of execution. One would expect this graph to have a flat top. The steep decline in the heap space may indicate that the application crashed after 2:00. The second graph shows that the outliers in real execution time, discussed above, occur near 2:00. when the Java heap seems to be quite full. The third graph shows that Full GCs are infrequent during the first few hours of execution. The rate of Full GC's, (the slope of the cummulative Full GC line), changes near midnight.   plot(clipped.g1gc.z[,c("AfterSize","RealTime","FullCount")], xlab="Time of Day", col=c("#1b9e77","red","#1b9e77")) GC Analysis of heap recovered Each GC trace includes the amount of heap space in use before and after the individual GC event. During garbage coolection, unreferenced objects are identified, the space holding the unreferenced objects is freed, and thus, the difference in before and after usage indicates how much space has been freed. The following box plot and bar chart both demonstrate the same point - the amount of heap space freed per garbage colloection is surprisingly low. par(mfrow=c(2,1)) boxplot(as.vector(clipped.g1gc.z$Delta), main="Amount of Heap Recovered per GC Pass", xlab="Size in KB", horizontal = TRUE, col="red") hist(as.vector(clipped.g1gc.z$Delta), main="Amount of Heap Recovered per GC Pass", xlab="Size in KB", breaks=100, col="red") box(which = "outer", lty = "solid") This graph is the most interesting. The dark blue area shows how much heap is occupied by referenced Java objects. This represents memory that holds live data. The red fringe at the top shows how much data was recovered after each garbage collection. barplot(clipped.g1gc.z[,c("AfterSize","Delta")], col=c("#7570b3","#e7298a"), xlab="Time of Day", border=NA) legend("topleft", c("Live Objects","Heap Recovered on GC"), fill=c("#7570b3","#e7298a")) box(which = "outer", lty = "solid") When I discuss the data in the log files with the customer, I will ask for an explaination for the large amount of referenced data resident in the Java heap. There are two are posibilities: There is a memory leak and the amount of space required to hold referenced objects will continue to grow, limited only by the maximum heap size. After the maximum heap size is reached, the JVM will throw an “Out of Memory” exception every time that the application tries to allocate a new object. If this is the case, the aplication needs to be debugged to identify why old objects are referenced when they are no longer needed. The application has a legitimate requirement to keep a large amount of data in memory. The customer may want to further increase the maximum heap size. Another possible solution would be to partition the application across multiple cluster nodes, where each node has responsibility for managing a unique subset of the data. Conclusion In conclusion, R is a very powerful tool for the analysis of Java garbage collection log files. The primary difficulty is data cleansing so that information can be read into an R data frame. Once the data has been read into R, a rich set of tools may be used for thorough evaluation.

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• Samsung Galaxy S2 ROM compilation error?

  - by Bashir

  I'm running Ubuntu 12.04 X64 and have installed all the tools(Toolchain: arm-2010q1 and Samsung Galaxy S2 source as given Here) to compile a ROM. When I run make Command I'm getting this error: kernel/built-in.o: In function `cpufreq_table_show': cpu_pm.c:(.text+0x39b64): undefined reference to `cpufreq_frequency_get_table' kernel/built-in.o: In function `cpufreq_max_limit_store': cpu_pm.c:(.text+0x39cd4): undefined reference to `omap_cpufreq_max_limit' cpu_pm.c:(.text+0x39d04): undefined reference to `omap_cpufreq_max_limit_free' cpu_pm.c:(.text+0x39d24): undefined reference to `omap_cpufreq_max_limit_free' kernel/built-in.o: In function `cpufreq_min_limit_store': cpu_pm.c:(.text+0x39dd4): undefined reference to `omap_cpufreq_min_limit' cpu_pm.c:(.text+0x39e04): undefined reference to `omap_cpufreq_min_limit_free' cpu_pm.c:(.text+0x39e24): undefined reference to `omap_cpufreq_min_limit_free' make: *** [.tmp_vmlinux1] Error 1

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