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• Understanding MotionEvent to implement a virtual DPad and Buttons on Android (Multitouch)

  - by Fabio Gomes

  I once implemented a DPad in XNA and now I'm trying to port it to android, put, I still don't get how the touch events work in android, the more I read the more confused I get. Here is the code I wrote so far, it works, but guess that it will only handle one touch point. public boolean onTouchEvent(MotionEvent event) { if (event.getPointerCount() == 0) return true; int touchX = -1; int touchY = -1; pressedDirection = DPadDirection.None; int actionCode = event.getAction() & MotionEvent.ACTION_MASK; if (actionCode == MotionEvent.ACTION_UP) { if (event.getPointerId(0) == idDPad) { pressedDirection = DPadDirection.None; idDPad = -1; } } else if (actionCode == MotionEvent.ACTION_DOWN || actionCode == MotionEvent.ACTION_MOVE) { touchX = (int)event.getX(); touchY = (int)event.getY(); if (rightRect.contains(touchX, touchY)) pressedDirection = DPadDirection.Right; else if (leftRect.contains(touchX, touchY)) pressedDirection = DPadDirection.Left; else if (upRect.contains(touchX, touchY)) pressedDirection = DPadDirection.Up; else if (downRect.contains(touchX, touchY)) pressedDirection = DPadDirection.Down; if (pressedDirection != DPadDirection.None) idDPad = event.getPointerId(0); } return true; } The logic is: Test if there is a "DOWN" or "MOVED" event, then if one of this events collides with one of the 4 rectangles of my DPad, I set the pressedDirectin variable to the side of the touch event, then I read the DPad actual pressed direction in my Update() event on another class. The thing I'm not sure, is how do I get track of the touch points, I store the ID of the touch point which generated the diretion that is being stored (last one), so when this ID is released I set the Direction to None, but I'm really confused about how to handle this in android, here is the code I had in XNA: public override void Update(GameTime gameTime) { PressedDirection = DpadDirection.None; foreach (TouchLocation _touchLocation in TouchPanel.GetState()) { if (_touchLocation.State == TouchLocationState.Released) { if (_touchLocation.Id == _idDPad) { PressedDirection = DpadDirection.None; _idDPad = -1; } } else if (_touchLocation.State == TouchLocationState.Pressed || _touchLocation.State == TouchLocationState.Moved) { _intersectRect.X = (int)_touchLocation.Position.X; _intersectRect.Y = (int)_touchLocation.Position.Y; _intersectRect.Width = 1; _intersectRect.Height = 1; if (_intersectRect.Intersects(_rightRect)) PressedDirection = DpadDirection.Right; else if (_intersectRect.Intersects(_leftRect)) PressedDirection = DpadDirection.Left; else if (_intersectRect.Intersects(_upRect)) PressedDirection = DpadDirection.Up; else if (_intersectRect.Intersects(_downRect)) PressedDirection = DpadDirection.Down; if (PressedDirection != DpadDirection.None) { _idDPad = _touchLocation.Id; continue; } } } base.Update(gameTime); } So, first of all: Am I doing this correctly? if not, why? I don't want my DPad to handle multiple directions, but I still didn't get how to handle the multiple touch points, is the event called for every touch point, or all touch points comes in a single call? I still don't get it.

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• SSIS – Delete all files except for the most recent one

  - by jorg

  Quite often one or more sources for a data warehouse consist of flat files. Most of the times these files are delivered as a zip file with a date in the file name, for example FinanceDataExport_20100528.zip Currently I work at a project that does a full load into the data warehouse every night. A zip file with some flat files in it is dropped in a directory on a daily basis. Sometimes there are multiple zip files in the directory, this can happen because the ETL failed or somebody puts a new zip file in the directory manually. Because the ETL isn’t incremental only the most recent file needs to be loaded. To implement this I used the simple code below; it checks which file is the most recent and deletes all other files. Note: In a previous blog post I wrote about unzipping zip files within SSIS, you might also find this useful: SSIS – Unpack a ZIP file with the Script Task Public Sub Main() 'Use this piece of code to loop through a set of files in a directory 'and delete all files except for the most recent one based on a date in the filename. 'File name example: 'DataExport_20100413.zip Dim rootDirectory As New DirectoryInfo(Dts.Variables("DirectoryFromSsisVariable").Value.ToString) Dim mostRecentFile As String = "" Dim currentFileDate As Integer Dim mostRecentFileDate As Integer = 0 'Check which file is the most recent For Each fi As FileInfo In rootDirectory.GetFiles("*.zip") currentFileDate = CInt(Left(Right(fi.Name, 12), 8)) 'Get date from current filename (based on a file that ends with: YYYYMMDD.zip) If currentFileDate > mostRecentFileDate Then mostRecentFileDate = currentFileDate mostRecentFile = fi.Name End If Next 'Delete all files except the most recent one For Each fi As FileInfo In rootDirectory.GetFiles("*.zip") If fi.Name <> mostRecentFile Then File.Delete(rootDirectory.ToString + "\" + fi.Name) End If Next Dts.TaskResult = ScriptResults.Success End Sub Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Software for "High-level" source code (C++) Management

  - by Korchkidu

  after a lot of small-medium projects, I have a lot of libraries and test programs here and there. Also, I must admit that some of the "best practices" I learnt are not that "good" IMHO. In particular, documenting your code and making a "high-level" documentation is not useful in practice: High-level documentation are not maintain up to date = I prefer to read the source code directly; Browsing generated developer documentation is a pain (IMHO) = I prefer to read the source code directly. For that reason, I am looking for a tool who could help me organize all my source code directories in a more "readable manner". What I need is a tool which: Maintains an UML diagram from C++ source code. I don't need source code generation from UML; USE CASE: I am in this super-tool, I notice a design issue, I change the source code, when I get back, the UML diagram is updated; Maintains easily browsable call graphs; Lists references to methods, variables, etc. For example, when I want to see where/when a method is called; Helps writing pseudo-code from C++; Embeds a nice C++ source code browser; Is Open Source would be great; Works at least on Win7. The focus of this tool should be to browse source code to understand what's going on. For example, when you have a newcomer and you need him to go through source code. Do you know any great tool? Thanks in advance. PS: please do not answer doxygen (great tool however).

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• Converting Openfire IM datetime values in SQL Server to / from VARCHAR(15) and DATETIME data types

  - by Brian Biales

  A client is using Openfire IM for their users, and would like some custom queries to audit user conversations (which are stored by Openfire in tables in the SQL Server database). Because Openfire supports multiple database servers and multiple platforms, the designers chose to store all date/time stamps in the database as 15 character strings, which get converted to Java Date objects in their code (Openfire is written in Java).  I did some digging around, and, so I don't forget and in case someone else will find this useful, I will put the simple algorithms here for converting back and forth between SQL DATETIME and the Java string representation. The Java string representation is the number of milliseconds since 1/1/1970.  SQL Server's DATETIME is actually represented as a float, the value being the number of days since 1/1/1900, the portion after the decimal point representing the hours/minutes/seconds/milliseconds... as a fractional part of a day.  Try this and you will see this is true:     SELECT CAST(0 AS DATETIME) and you will see it returns the date 1/1/1900. The difference in days between SQL Server's 0 date of 1/1/1900 and the Java representation's 0 date of 1/1/1970 is found easily using the following SQL:   SELECT DATEDIFF(D, '1900-01-01', '1970-01-01') which returns 25567.  There are 25567 days between these dates. So to convert from the Java string to SQL Server's date time, we need to convert the number of milliseconds to a floating point representation of the number of days since 1/1/1970, then add the 25567 to change this to the number of days since 1/1/1900.  To convert to days, you need to divide the number by 1000 ms/s, then by  60 seconds/minute, then by 60 minutes/hour, then by 24 hours/day.  Or simply divide by 1000*60*60*24, or 86400000.   So, to summarize, we need to cast this string as a float, divide by 86400000 milliseconds/day, then add 25567 days, and cast the resulting value to a DateTime.  Here is an example:   DECLARE @tmp as VARCHAR(15)   SET @tmp = '1268231722123'   SELECT @tmp as JavaTime, CAST((CAST(@tmp AS FLOAT) / 86400000) + 25567 AS DATETIME) as SQLTime   To convert from SQL datetime back to the Java time format is not quite as simple, I found, because floats of that size do not convert nicely to strings, they end up in scientific notation using the CONVERT function or CAST function.  But I found a couple ways around that problem. You can convert a date to the number of  seconds since 1/1/1970 very easily using the DATEDIFF function, as this value fits in an Int.  If you don't need to worry about the milliseconds, simply cast this integer as a string, and then concatenate '000' at the end, essentially multiplying this number by 1000, and making it milliseconds since 1/1/1970.  If, however, you do care about the milliseconds, you will need to use DATEPART to get the milliseconds part of the date, cast this integer to a string, and then pad zeros on the left to make sure this is three digits, and concatenate these three digits to the number of seconds string above.  And finally, I discovered by casting to DECIMAL(15,0) then to VARCHAR(15), I avoid the scientific notation issue.  So here are all my examples, pick the one you like best... First, here is the simple approach if you don't care about the milliseconds:   DECLARE @tmp as VARCHAR(15)   DECLARE @dt as DATETIME   SET @dt = '2010-03-10 14:35:22.123'   SET @tmp = CAST(DATEDIFF(s, '1970-01-01 00:00:00' , @dt) AS VARCHAR(15)) + '000'   SELECT @tmp as JavaTime, @dt as SQLTime If you want to keep the milliseconds:   DECLARE @tmp as VARCHAR(15)   DECLARE @dt as DATETIME   DECLARE @ms as int   SET @dt = '2010-03-10 14:35:22.123'   SET @ms as DATEPART(ms, @dt)   SET @tmp = CAST(DATEDIFF(s, '1970-01-01 00:00:00' , @dt) AS VARCHAR(15))           + RIGHT('000' + CAST(@ms AS VARCHAR(3)), 3)   SELECT @tmp as JavaTime, @dt as SQLTime Or, in one fell swoop:   DECLARE @dt as DATETIME   SET @dt = '2010-03-10 14:35:22.123'   SELECT @dt as SQLTime     , CAST(DATEDIFF(s, '1970-01-01 00:00:00' , @dt) AS VARCHAR(15))           + RIGHT('000' + CAST( DATEPART(ms, @dt) AS VARCHAR(3)), 3) as JavaTime   And finally, a way to simply reverse the math used converting from Java date to SQL date. Note the parenthesis - watch out for operator precedence, you want to subtract, then multiply:   DECLARE @dt as DATETIME   SET @dt = '2010-03-10 14:35:22.123'   SELECT @dt as SQLTime     , CAST(CAST((CAST(@dt as Float) - 25567.0) * 86400000.0 as DECIMAL(15,0)) as VARCHAR(15)) as JavaTime Interestingly, I found that converting to SQL Date time can lose some accuracy, when I converted the time above to Java time then converted  that back to DateTime, the number of milliseconds is 120, not 123.  As I am not interested in the milliseconds, this is ok for me.  But you may want to look into using DateTime2 in SQL Server 2008 for more accuracy.

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• Innovative SPARC: Lighting a Fire Under Oracle's New Hardware Business

  - by Paulo Folgado

  "There's a certain level of things you can do with commercially available parts," says Oracle Executive Vice President Mike Splain. But, he notes, you can do so much more if you design the parts yourself. Mike Splain,EVP, OracleYou can, for example, design cryptographic accelerators into your microprocessors so customers can run their networks fully encrypted if they choose.Of course, it helps if you've already built multiple processing "cores" into those chips so they can handle all that encrypting and decrypting while still getting their other work done.System on a ChipAs the leader of Oracle Microelectronics, Mike knows how implementing clever innovations in silicon can give systems a real competitive advantage.The SPARC microprocessors that his team designed at Sun pioneered the concept of multiple cores several years ago, and the UltraSPARC T2 processor--the industry's first "system on a chip"--packs up to eight cores per chip, each running as many as eight threads at once. That's the most cores and threads of any general-purpose processor. Looking back, Mike points out that the real value of large enterprise-class servers was their ability to run a lot of very large applications in parallel."The beauty of our CMT [chip multi-threading] machines is you can get that same kind of parallel-processing capability at a much lower cost and in a much smaller footprint," he says.The Whole StackWhat has Mike excited these days is that suddenly the opportunity to innovate is much bigger as part of Oracle."In my group, we used to look up the software stack and say, 'We can do any innovation we want, provided the only thing we have to change is what's in the Solaris operating system'--or maybe Java," he says. "If we wanted to change things beyond that, we'd have to go outside the walls of Sun and we'd have to convince the vendors: 'You have to align with us, you have to test with us, you have to build for us, and then you'll reap the benefits.' Now we get access to the entire stack. We can look all the way through the stack and say, 'Okay, what would make the database go faster? What would make the middleware go faster?'"Changing the WorldMike and his microelectronics team also like the fact that Oracle is not just any software company. We're #1 in database, middleware, business intelligence, and more."We're like all the other engineers from Sun; we believe we can change the world, if we can just figure out how to get people to pay attention to us," he says. "Now there's a mechanism at Oracle--much more so than we ever had at Sun."He notes, too, that every innovation in SPARC has involved some combination of hardware and softwareoptimization."Take our cryptography framework, for example. Sure, we can accelerate rapidly, but the Solaris OS has to provide the right set of interfaces that applications can tap into," Mike says. "Same thing with our multicore architecture. We have to have software that can utilize all those threads and run in parallel." His engineers, he points out, have never been interested in producing chips that sell as mere components."Our chips are always designed to go into systems and be combined with various pieces of software," he says. "Our job is to enable the creation of systems."

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• Is recursion really bad?

  - by dotneteer

  After my previous post about the stack space, it appears that there is perception from the feedback that recursion is bad and we should avoid deep recursion. After writing a compiler, I know that the modern computer and compiler are complex enough and one cannot automatically assume that a hand crafted code would out-perform the compiler optimization. The only way is to do some prototype to find out. So why recursive code may not perform as well? Compilers place frames on a stack. In additional to arguments and local variables, compiles also need to place frame and program pointers on the frame, resulting in overheads. So why hand-crafted code may not performance as well? The stack used by a compiler is a simpler data structure and can grow and shrink cleanly. To replace recursion with out own stack, our stack is allocated in the heap that is far more complicated to manage. There could be overhead as well if the compiler needs to mark objects for garbage collection. Compiler also needs to worry about the memory fragmentation. Then there is additional complexity: CPUs have registers and multiple levels of cache. Register access is a few times faster than in-CPU cache access and is a few 10s times than on-board memory access. So it is up to the OS and compiler to maximize the use of register and in-CPU cache. For my particular problem, I did an experiment to rewrite my c# version of recursive code with a loop and stack approach. So here are the outcomes of the two approaches:   Recursive call Loop and Stack Lines of code for the algorithm 17 46 Speed Baseline 3% faster Readability Clean Far more complex So at the end, I was able to achieve 3% better performance with other drawbacks. My message is never assuming your sophisticated approach would automatically work out better than a simpler approach with a modern computer and compiler. Gage carefully before committing to a more complex approach.

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• SQL SERVER – T-SQL Constructs – *= and += – SQL in Sixty Seconds #009 – Video

  - by pinaldave

  There were plenty of request for Vinod Kumar to come back with SQL in Sixty Seconds with T-SQL constructs after his very first well received construct video T-SQL Constructs – Declaration and Initialization – SQL in Sixty Seconds #003 – Video. Vinod finally comes up with this new episode where he demonstrates how dot net developer can write familiar syntax using T-SQL constructs. T-SQL has many enhancements which are less explored. In this quick video we learn how T-SQL Constructions works. We will explore Declaration and Initialization of T-SQL Constructions. We can indeed improve our efficiency using this kind of simple tricks. I strongly suggest that all of us should keep this kind of tricks in our toolbox. More on Errors: Declare and Assign Variable in Single Statement Declare Multiple Variables in One Statement I encourage you to submit your ideas for SQL in Sixty Seconds. We will try to accommodate as many as we can. If we like your idea we promise to share with you educational material. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Video

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• Formatting Dates, Times and Numbers in ASP.NET

  Formatting is the process of converting a variable from its native type into a string representation. Anytime you display a DateTime or numeric variables in an ASP.NET page, you are formatting that variable from its native type into some sort of string representation. How a DateTime or numeric variable is formatted depends on the culture settings and the format string. Because dates and numeric values are formatted differently across cultures, the .NET Framework bases its formatting on the specified culture settings. By default, the formatting routines use the culture settings defined on the web server, but you can indicate that a particular culture be used anytime you format. In addition to the culture settings, formatting is also affected by a format string, which spells out the formatting details to apply. The .NET Framework contains a bounty of format strings. There are standard format strings, which are typically a single letter that applies detailed formatting logic. For example, the "C" format specifier will format a numeric type as a currency value; the "Y" format specifier displays the month name and four-digit year of the specified DateTime value. There are also custom format strings, which display a apply a very specific formatting rule. These custom format strings can be put together to build more intricate formats. For instance, the format string "dddd, MMMM d" displays the full day of the week name followed by a comma followed by the full name of the month followed by the day of the month. For more involved formatting scenarios, where neither the standard or custom format strings cut the mustard, you can always create your own formatting extension methods. This article explores the standard format strings for dates, times and numbers and includes a number of custom formatting methods I've created and use in my own projects. There's also a demo application you can download that lets you specify a culture and then shows you the output for the standard format strings for the selected culture. Read on to learn more! Read More >

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• Announcing ASP.NET MVC 3 (Release Candidate 2)

  - by ScottGu

  Earlier today the ASP.NET team shipped the final release candidate (RC2) for ASP.NET MVC 3.  You can download and install it here. Almost there… Today’s RC2 release is the near-final release of ASP.NET MVC 3, and is a true “release candidate” in that we are hoping to not make any more code changes with it.  We are publishing it today so that people can do final testing with it, let us know if they find any last minute “showstoppers”, and start updating their apps to use it.  We will officially ship the final ASP.NET MVC 3 “RTM” build in January. Works with both VS 2010 and VS 2010 SP1 Beta Today’s ASP.NET MVC 3 RC2 release works with both the shipping version of Visual Studio 2010 / Visual Web Developer 2010 Express, as well as the newly released VS 2010 SP1 Beta.  This means that you do not need to install VS 2010 SP1 (or the SP1 beta) in order to use ASP.NET MVC 3.  It works just fine with the shipping Visual Studio 2010.  I’ll do a blog post next week, though, about some of the nice additional feature goodies that come with VS 2010 SP1 (including IIS Express and SQL CE support within VS) which make the dev experience for both ASP.NET Web Forms and ASP.NET MVC even better. Bugs and Perf Fixes Today’s ASP.NET MVC 3 RC2 build contains many bug fixes and performance optimizations.  Our latest performance tests indicate that ASP.NET MVC 3 is now faster than ASP.NET MVC 2, and that existing ASP.NET MVC applications will experience a slight performance increase when updated to run using ASP.NET MVC 3. Final Tweaks and Fit-N-Finish In addition to bug fixes and performance optimizations, today’s RC2 build contains a number of last-minute feature tweaks and “fit-n-finish” changes for the new ASP.NET MVC 3 features.  The feedback and suggestions we’ve received during the public previews has been invaluable in guiding these final tweaks, and we really appreciate people’s support in sending this feedback our way.  Below is a short-list of some of the feature changes/tweaks made between last month’s ASP.NET MVC 3 RC release and today’s ASP.NET MVC 3 RC2 release: jQuery updates and addition of jQuery UI The default ASP.NET MVC 3 project templates have been updated to include jQuery 1.4.4 and jQuery Validation 1.7.  We are also excited to announce today that we are including jQuery UI within our default ASP.NET project templates going forward.  jQuery UI provides a powerful set of additional UI widgets and capabilities.  It will be added by default to your project’s \scripts folder when you create new ASP.NET MVC 3 projects. Improved View Scaffolding The T4 templates used for scaffolding views with the Add-View dialog now generates views that use Html.EditorFor instead of helpers such as Html.TextBoxFor. This change enables you to optionally annotate models with metadata (using data annotation attributes) to better customize the output of your UI at runtime. The Add View scaffolding also supports improved detection and usage of primary key information on models (including support for naming conventions like ID, ProductID, etc).  For example: the Add View dialog box uses this information to ensure that the primary key value is not scaffold as an editable form field, and that links between views are auto-generated correctly with primary key information. The default Edit and Create templates also now include references to the jQuery scripts needed for client validation.  Scaffold form views now support client-side validation by default (no extra steps required).  Client-side validation with ASP.NET MVC 3 is also done using an unobtrusive javascript approach – making pages fast and clean. [ControllerSessionState] –> [SessionState] ASP.NET MVC 3 adds support for session-less controllers.  With the initial RC you used a [ControllerSessionState] attribute to specify this.  We shortened this in RC2 to just be [SessionState]: Note that in addition to turning off session state, you can also set it to be read-only (which is useful for webfarm scenarios where you are reading but not updating session state on a particular request). [SkipRequestValidation] –> [AllowHtml] ASP.NET MVC includes built-in support to protect against HTML and Cross-Site Script Injection Attacks, and will throw an error by default if someone tries to post HTML content as input.  Developers need to explicitly indicate that this is allowed (and that they’ve hopefully built their app to securely support it) in order to enable it. With ASP.NET MVC 3, we are also now supporting a new attribute that you can apply to properties of models/viewmodels to indicate that HTML input is enabled, which enables much more granular protection in a DRY way.  In last month’s RC release this attribute was named [SkipRequestValidation].  With RC2 we renamed it to [AllowHtml] to make it more intuitive: Setting the above [AllowHtml] attribute on a model/viewmodel will cause ASP.NET MVC 3 to turn off HTML injection protection when model binding just that property. Html.Raw() helper method The new Razor view engine introduced with ASP.NET MVC 3 automatically HTML encodes output by default.  This helps provide an additional level of protection against HTML and Script injection attacks. With RC2 we are adding a Html.Raw() helper method that you can use to explicitly indicate that you do not want to HTML encode your output, and instead want to render the content “as-is”: ViewModel/View –> ViewBag ASP.NET MVC has (since V1) supported a ViewData[] dictionary within Controllers and Views that enables developers to pass information from a Controller to a View in a late-bound way.  This approach can be used instead of, or in combination with, a strongly-typed model class.  The below code demonstrates a common use case – where a strongly typed Product model is passed to the view in addition to two late-bound variables via the ViewData[] dictionary: With ASP.NET MVC 3 we are introducing a new API that takes advantage of the dynamic type support within .NET 4 to set/retrieve these values.  It allows you to use standard “dot” notation to specify any number of additional variables to be passed, and does not require that you create a strongly-typed class to do so.  With earlier previews of ASP.NET MVC 3 we exposed this API using a dynamic property called “ViewModel” on the Controller base class, and with a dynamic property called “View” within view templates.  A lot of people found the fact that there were two different names confusing, and several also said that using the name ViewModel was confusing in this context – since often you create strongly-typed ViewModel classes in ASP.NET MVC, and they do not use this API.  With RC2 we are exposing a dynamic property that has the same name – ViewBag – within both Controllers and Views.  It is a dynamic collection that allows you to pass additional bits of data from your controller to your view template to help generate a response.  Below is an example of how we could use it to pass a time-stamp message as well as a list of all categories to our view template: Below is an example of how our view template (which is strongly-typed to expect a Product class as its model) can use the two extra bits of information we passed in our ViewBag to generate the response.  In particular, notice how we are using the list of categories passed in the dynamic ViewBag collection to generate a dropdownlist of friendly category names to help set the CategoryID property of our Product object.  The above Controller/View combination will then generate an HTML response like below.    Output Caching Improvements ASP.NET MVC 3’s output caching system no longer requires you to specify a VaryByParam property when declaring an [OutputCache] attribute on a Controller action method.  MVC3 now automatically varies the output cached entries when you have explicit parameters on your action method – allowing you to cleanly enable output caching on actions using code like below: In addition to supporting full page output caching, ASP.NET MVC 3 also supports partial-page caching – which allows you to cache a region of output and re-use it across multiple requests or controllers.  The [OutputCache] behavior for partial-page caching was updated with RC2 so that sub-content cached entries are varied based on input parameters as opposed to the URL structure of the top-level request – which makes caching scenarios both easier and more powerful than the behavior in the previous RC. @model declaration does not add whitespace In earlier previews, the strongly-typed @model declaration at the top of a Razor view added a blank line to the rendered HTML output. This has been fixed so that the declaration does not introduce whitespace. Changed "Html.ValidationMessage" Method to Display the First Useful Error Message The behavior of the Html.ValidationMessage() helper was updated to show the first useful error message instead of simply displaying the first error. During model binding, the ModelState dictionary can be populated from multiple sources with error messages about the property, including from the model itself (if it implements IValidatableObject), from validation attributes applied to the property, and from exceptions thrown while the property is being accessed. When the Html.ValidationMessage() method displays a validation message, it now skips model-state entries that include an exception, because these are generally not intended for the end user. Instead, the method looks for the first validation message that is not associated with an exception and displays that message. If no such message is found, it defaults to a generic error message that is associated with the first exception. RemoteAttribute “Fields” -> “AdditionalFields” ASP.NET MVC 3 includes built-in remote validation support with its validation infrastructure.  This means that the client-side validation script library used by ASP.NET MVC 3 can automatically call back to controllers you expose on the server to determine whether an input element is indeed valid as the user is editing the form (allowing you to provide real-time validation updates). You can accomplish this by decorating a model/viewmodel property with a [Remote] attribute that specifies the controller/action that should be invoked to remotely validate it.  With the RC this attribute had a “Fields” property that could be used to specify additional input elements that should be sent from the client to the server to help with the validation logic.  To improve the clarity of what this property does we have renamed it to “AdditionalFields” with today’s RC2 release. ViewResult.Model and ViewResult.ViewBag Properties The ViewResult class now exposes both a “Model” and “ViewBag” property off of it.  This makes it easier to unit test Controllers that return views, and avoids you having to access the Model via the ViewResult.ViewData.Model property. Installation Notes You can download and install the ASP.NET MVC 3 RC2 build here.  It can be installed on top of the previous ASP.NET MVC 3 RC release (it should just replace the bits as part of its setup). The one component that will not be updated by the above setup (if you already have it installed) is the NuGet Package Manager.  If you already have NuGet installed, please go to the Visual Studio Extensions Manager (via the Tools –> Extensions menu option) and click on the “Updates” tab.  You should see NuGet listed there – please click the “Update” button next to it to have VS update the extension to today’s release. If you do not have NuGet installed (and did not install the ASP.NET MVC RC build), then NuGet will be installed as part of your ASP.NET MVC 3 setup, and you do not need to take any additional steps to make it work. Summary We are really close to the final ASP.NET MVC 3 release, and will deliver the final “RTM” build of it next month.  It has been only a little over 7 months since ASP.NET MVC 2 shipped, and I’m pretty amazed by the huge number of new features, improvements, and refinements that the team has been able to add with this release (Razor, Unobtrusive JavaScript, NuGet, Dependency Injection, Output Caching, and a lot, lot more).  I’ll be doing a number of blog posts over the next few weeks talking about many of them in more depth. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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• Windows Azure Use Case: Web Applications

  - by BuckWoody

  This is one in a series of posts on when and where to use a distributed architecture design in your organization's computing needs. You can find the main post here: http://blogs.msdn.com/b/buckwoody/archive/2011/01/18/windows-azure-and-sql-azure-use-cases.aspx  Description: Many applications have a requirement to be located outside of the organization’s internal infrastructure control. For instance, the company website for a brick-and-mortar retail company may want to post not only static but interactive content to be available to their external customers, and not want the customers to have access inside the organization’s firewall. There are also cases of pure web applications used for a great many of the internal functions of the business. This allows for remote workers, shared customer/employee workloads and data and other advantages. Some firms choose to host these web servers internally, others choose to contract out the infrastructure to an “ASP” (Application Service Provider) or an Infrastructure as a Service (IaaS) company. In any case, the design of these applications often resembles the following: In this design, a server (or perhaps more than one) hosts the presentation function (http or https) access to the application, and this same system may hold the computational aspects of the program. Authorization and Access is controlled programmatically, or is more open if this is a customer-facing application. Storage is either placed on the same or other servers, hosted within an RDBMS or NoSQL database, or a combination of the options, all coded into the application. High-Availability within this scenario is often the responsibility of the architects of the application, and by purchasing more hosting resources which must be built, licensed and configured, and manually added as demand requires, although some IaaS providers have a partially automatic method to add nodes for scale-out, if the architecture of the application supports it. Disaster Recovery is the responsibility of the system architect as well. Implementation: In a Windows Azure Platform as a Service (PaaS) environment, many of these architectural considerations are designed into the system. The Azure “Fabric” (not to be confused with the Azure implementation of Application Fabric - more on that in a moment) is designed to provide scalability. Compute resources can be added and removed programmatically based on any number of factors. Balancers at the request-level of the Fabric automatically route http and https requests. The fabric also provides High-Availability for storage and other components. Disaster recovery is a shared responsibility between the facilities (which have the ability to restore in case of catastrophic failure) and your code, which should build in recovery. In a Windows Azure-based web application, you have the ability to separate out the various functions and components. Presentation can be coded for multiple platforms like smart phones, tablets and PC’s, while the computation can be a single entity shared between them. This makes the applications more resilient and more object-oriented, and lends itself to a SOA or Distributed Computing architecture. It is true that you could code up a similar set of functionality in a traditional web-farm, but the difference here is that the components are built into the very design of the architecture. The API’s and DLL’s you call in a Windows Azure code base contains components as first-class citizens. For instance, if you need storage, it is simply called within the application as an object.  Computation has multiple options and the ability to scale linearly. You also gain another component that you would either have to write or bolt-in to a typical web-farm: the Application Fabric. This Windows Azure component provides communication between applications or even to on-premise systems. It provides authorization in either person-based or claims-based perspectives. SQL Azure provides relational storage as another option, and can also be used or accessed from on-premise systems. It should be noted that you can use all or some of these components individually. Resources: Design Strategies for Scalable Active Server Applications - http://msdn.microsoft.com/en-us/library/ms972349.aspx  Physical Tiers and Deployment  - http://msdn.microsoft.com/en-us/library/ee658120.aspx

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• Windows Azure Use Case: Agility

  - by BuckWoody

  This is one in a series of posts on when and where to use a distributed architecture design in your organization's computing needs. You can find the main post here: http://blogs.msdn.com/b/buckwoody/archive/2011/01/18/windows-azure-and-sql-azure-use-cases.aspx  Description: Agility in this context is defined as the ability to quickly develop and deploy an application. In theory, the speed at which your organization can develop and deploy an application on available hardware is identical to what you could deploy in a distributed environment. But in practice, this is not always the case. Having an option to use a distributed environment can be much faster for the deployment and even the development process. Implementation: When an organization designs code, they are essentially becoming a Software-as-a-Service (SaaS) provider to their own organization. To do that, the IT operations team becomes the Infrastructure-as-a-Service (IaaS) to the development teams. From there, the software is developed and deployed using an Application Lifecycle Management (ALM) process. A simplified view of an ALM process is as follows: Requirements Analysis Design and Development Implementation Testing Deployment to Production Maintenance In an on-premise environment, this often equates to the following process map: Requirements Business requirements formed by Business Analysts, Developers and Data Professionals. Analysis Feasibility studies, including physical plant, security, manpower and other resources. Request is placed on the work task list if approved. Design and Development Code written according to organization’s chosen methodology, either on-premise or to multiple development teams on and off premise. Implementation Code checked into main branch. Code forked as needed. Testing Code deployed to on-premise Testing servers. If no server capacity available, more resources procured through standard budgeting and ordering processes. Manual and automated functional, load, security, etc. performed. Deployment to Production Server team involved to select platform and environments with available capacity. If no server capacity available, standard budgeting and procurement process followed. If no server capacity available, systems built, configured and put under standard organizational IT control. Systems configured for proper operating systems, patches, security and virus scans. System maintenance, HA/DR, backups and recovery plans configured and put into place. Maintenance Code changes evaluated and altered according to need. In a distributed computing environment like Windows Azure, the process maps a bit differently: Requirements Business requirements formed by Business Analysts, Developers and Data Professionals. Analysis Feasibility studies, including budget, security, manpower and other resources. Request is placed on the work task list if approved. Design and Development Code written according to organization’s chosen methodology, either on-premise or to multiple development teams on and off premise. Implementation Code checked into main branch. Code forked as needed. Testing Code deployed to Azure. Manual and automated functional, load, security, etc. performed. Deployment to Production Code deployed to Azure. Point in time backup and recovery plans configured and put into place.(HA/DR and automated backups already present in Azure fabric) Maintenance Code changes evaluated and altered according to need. This means that several steps can be removed or expedited. It also means that the business function requesting the application can be held directly responsible for the funding of that request, speeding the process further since the IT budgeting process may not be involved in the Azure scenario. An additional benefit is the “Azure Marketplace”, In effect this becomes an app store for Enterprises to select pre-defined code and data applications to mesh or bolt-in to their current code, possibly saving development time. Resources: Whitepaper download- What is ALM?  http://go.microsoft.com/?linkid=9743693  Whitepaper download - ALM and Business Strategy: http://go.microsoft.com/?linkid=9743690  LiveMeeting Recording on ALM and Windows Azure (registration required, but free): http://www.microsoft.com/uk/msdn/visualstudio/contact-us.aspx?sbj=Developing with Windows Azure (ALM perspective) - 10:00-11:00 - 19th Jan 2011

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• Creando controles personalizados para asp.net

  - by jaullo

  Si bien es cierto que asp.net contiene muchos controles que nos facilitan la vida, en muchas ocasiones requerimos funcionalidades adicionales. Una de las opciones es recurrir a la creación de controles personalizados. Este será el Primero de varios post que dedicare a mostrar como crear algunos controles personalizados utilizando elementos sumamente sencillos y faciles de entender. Para ello utilizaremos unicamente los regularexpressionvalidator y unas cuantas expresiones regulares. Para este ejemplo extenderemos la funcionalidad de un textbox para que valide números de tarjetas de crédito. Nuestro textbox deberá verificar que existan 16 números, en grupos de 4, separados por un - Entonces, creamos un nuevo proyecto de tipo control de servidor asp.net Primeramente importamos los espacios de nombres Imports System.ComponentModel Imports System.Web Imports System.Web.UI.WebControls Imports System.Web.UI   Segundo creamos nuestra clase Public Class TextboxCreditCardNumber end class Ahora,  le decimos a nuestra clase que vamos a heredar de textbox Public Class TextboxCreditCardNumber           Inherits TextBox end class Una vez que tenemos esto, nuestra base de programación esta lista, asi que vamos a codificar nuestra nueva funcionalidad Declaramos nuestra variables y una propiedad pública que contendrá el mensaje de error que debe ser devuelto al usuario, esta será publica para que pueda ser personalizada.    Private req As New RegularExpressionValidator     Private mstrmensaje As String = "Número de Tarjeta Invalido"     Public Property MensajeError() As String         Get             Return mstrmensaje         End Get         Set(ByVal value As String)             mstrmensaje = value         End Set     End Property   Ahora definimos el metodo OnInit de nuestro control, en el cual asignaremos las propiedad e inicializaremos nuestras funciones    Protected Overrides Sub OnInit(ByVal e As System.EventArgs)         req.ControlToValidate = MyBase.ID         req.ErrorMessage = mstrmensaje         req.Display = ValidatorDisplay.Dynamic         req.ValidationExpression = "^(\d{4}-){3}\d{4}$|^(\d{4} ){3}\d{4}$|^\d{16}$"         Controls.Add(New LiteralControl("&nbsp;"))         Controls.Add(req)         MyBase.OnInit(e)     End Sub   Y por último, definimos el evento render (que es el encarado de dibujar nuestro control) Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)         MyBase.Render(writer)         req.RenderControl(writer)     End Sub   Lo unico que nos queda ahora es compilar nuestra clase y añadir nuestro nuevo control al ToolBox de Controles para que pueda ser utilizado.

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• SQL SERVER – CXPACKET – Parallelism – Advanced Solution – Wait Type – Day 7 of 28

  - by pinaldave

  Earlier we discussed about the what is the common solution to solve the issue with CXPACKET wait time. Today I am going to talk about few of the other suggestions which can help to reduce the CXPACKET wait. If you are going to suggest that I should focus on MAXDOP and COST THRESHOLD – I totally agree. I have covered them in details in yesterday’s blog post. Today we are going to discuss few other way CXPACKET can be reduced. Potential Reasons: If data is heavily skewed, there are chances that query optimizer may estimate the correct amount of the data leading to assign fewer thread to query. This can easily lead to uneven workload on threads and may create CXPAKCET wait. While retrieving the data one of the thread face IO, Memory or CPU bottleneck and have to wait to get those resources to execute its tasks, may create CXPACKET wait as well. Data which is retrieved is on different speed IO Subsystem. (This is not common and hardly possible but there are chances). Higher fragmentations in some area of the table can lead less data per page. This may lead to CXPACKET wait. As I said the reasons here mentioned are not the major cause of the CXPACKET wait but any kind of scenario can create the probable wait time. Best Practices to Reduce CXPACKET wait: Refer earlier article regarding MAXDOP and Cost Threshold. De-fragmentation of Index can help as more data can be obtained per page. (Assuming close to 100 fill-factor) If data is on multiple files which are on multiple similar speed physical drive, the CXPACKET wait may reduce. Keep the statistics updated, as this will give better estimate to query optimizer when assigning threads and dividing the data among available threads. Updating statistics can significantly improve the strength of the query optimizer to render proper execution plan. This may overall affect the parallelism process in positive way. Bad Practice: In one of the recent consultancy project, when I was called in I noticed that one of the ‘experienced’ DBA noticed higher CXPACKET wait and to reduce them, he has increased the worker threads. The reality was increasing worker thread has lead to many other issues. With more number of the threads, more amount of memory was used leading memory pressure. As there were more threads CPU scheduler faced higher ‘Context Switching’ leading further degrading performance. When I explained all these to ‘experienced’ DBA he suggested that now we should reduce the number of threads. Not really! Lower number of the threads may create heavy stalling for parallel queries. I suggest NOT to touch the setting of number of the threads when dealing with CXPACKET wait. Read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and I no way claim it to be accurate. I suggest reading book on-line for further clarification. All the discussion of Wait Stats over here is generic and it varies by system to system. You are recommended to test this on development server before implementing to production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• A debugging experience with "highly compatible" ASP.NET 4.5

  - by Jeff

  I have to admit that I will pretty much upgrade software for no reason other than being on the latest version. I won't do it if it's super expensive (Adobe gets money from me about once every three or four years at best), but particularly with frameworks and stuff generally available as part of my MSDN subscription, I'll be bleeding edge. CoasterBuzz was running on the MVC 4 framework pretty much as soon as they did a "go live" license for it. I didn't really jump in head-first with Windows 8 and Visual Studio 2012, in part because I just wasn't interested in doing the reinstalls for each new version. Turns out there weren't that many revisions anyway. But when the final versions were released a week and a half ago, I jumped in. I saw on one of the Microsoft sites that .Net 4.5 was a "highly compatible in-place update" to the framework. Good enough for me. I was obviously running it by default in Windows 8, and installed it on my production server. I suppose it's "highly compatible," except when it isn't. Three of my sites are running with various flavors of the MVC version of POP Forums. All of them stopped working under ASP.NET 4.5. It was not immediately obvious what the problem might be beyond an exception indicating that there were no repository classes registered with Ninject, which I use for dependency injection in the forums. This was made all the more weird by the fact that it ran fine locally in the dev Web host. My first instinct was to spin up a Windows Server VM on my local box and put the remote debugger on it. (Side note: running multiple VM's on a Retina MacBook Pro with 16 gigs of RAM is pretty much the most awesome thing ever. I can't believe this computer is for real, and not a 50-pound tower under my desk.) What might have been going on in IIS that doesn't happen in Visual Studio? In the debugging process, I realized that I might be looking in the wrong place. POP Forums creates a Ninject container using a method called from a PreApplicationStartMethod attribute, and at that time registers a module (what Ninject uses to map interfaces to implementations) that maps all of the core dependencies. It also creates an instance of an HttpModule that originally hosted the "services" (search indexing, mailer, etc.), but now just records errors. That's all well and good, but the actual repository mapping, where data is actually read or persisted, happens in Application_Start() in global.asax. The idea there is that you can swap out the SqlSingleWebServer repos for something tuned for multiple servers, Oracle or something else. Of course, if I used something like StructureMap, which does convention-based mapping for dependency injection (a class implementing ISettingsRepository called SettingsRepository is automagically mapped), I wouldn't have to worry about it. In any case, the HttpModule, being instantiated before Application_Start() gets to run, would throw because there was no repo mapped where it could get settings from the database. This makes total sense. The fix is sort of a hack, where I don't setup the innards of the HttpModule until a call to its BeginRequest is made. I say it's a hack, because its primary function, logging exceptions, won't work until the app has warmed up. Still, this brings up an interesting question about the race condition, and what changed in 4.5 when it's running in IIS. In ASP.NET 4, it would appear that the code called via the PreApplicationStartMethod was either failing silently, and running again later, or it was getting to that code after Application_Start was called. In any case, weird thing. The real pain point I'm experiencing now is a bug in MVC 4 that is extremely serious because it renders the mobile/alternate view functionality very much broken.

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• Deferred vs Immediate execution in Linq

  - by Jalpesh P. Vadgama

  In this post, We are going to learn about Deferred vs Immediate execution in Linq.  There an interesting variations how Linq operators executes and in this post we are going to learn both Deferred execution and immediate execution. What is Deferred Execution? In the Deferred execution query will be executed and evaluated at the time of query variables usage. Let’s take an example to understand Deferred Execution better. Example: Following is a code for that. using System; using System.Collections.Generic; using System.Linq; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { var customers = new List<Customer>( new[] { new Customer{FirstName = "Jalpesh",LastName = "Vadgama"}, new Customer{FirstName = "Vishal",LastName = "Vadgama"}, new Customer{FirstName = "Tushar",LastName = "Maru"} } ); var newCustomers = customers.Where(c => c.LastName == "Vadgama"); customers.Add(new Customer {FirstName = "Teerth", LastName = "Vadgama"}); foreach (var c in newCustomers) { Console.WriteLine(c.FirstName); } } public class Customer { public string FirstName { get; set; } public string LastName { get; set; } } } } More on my personal blog @www.dotnetjalps.com

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• Ventajas y Beneficios de migrar a las últimas versiones de JD Edwards

  - by Ramon Riera

  La semana pasada realicé un webinar acerca de las Ventajas y Beneficios de migrar a las últimas versiones de JD Edwards EnterpriseOne. El objetivo no era contar en detalle todas las mejoras de las últimas versiones ya que son muchas y variables según la versión actual; si no resaltar algunos de los motivos generales por los que os valdría la pena migrar. En el video repaso la historia de JD Edwards y la estrategia y compromiso que Oracle tiene con el producto como se refleja en las políticas de Applications Unlimited, Lifetime Support y el roadmap del producto. También las principales mejoras que ha habido, especialmente centrándome en los 3 principales ejes de mejora que ha tenido y tiene JD Edwards: · El funcional con los nuevos módulos de Apparel Management, Fulfillment Managment y Environmental Accounting · Las mejoras que aporta la tecnología de Oracle, haciendo un especial énfasis en las mejoras en usabilidad de pantallas y uso del iPad · Las integraciones con el resto de aplicaciones de Oracle, como por ejemplo las aplicaciones analíticas de BI. Finalmente comento las facilidades que desde Oracle damos a los clientes para migrar y que se pueden resumir en la página web www.upgradejde.com dónde ponemos a disposición toda la información necesaria para planificar una migración como: Situación actual de mantenimiento de cada versión Productos y mejoras de cada versión Comparativas por versión tanto a nivel funcional como a nivel de cambios en la base de datos Consejos de migración para evaluar, planificar y ejecutar un proyecto de migración Toda la documentación de las versiones A continuación os djo el video:

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• Why does Ubuntu reset brightness settings at the loading screen?

  - by leugim

  Since I first installed Ubuntu 11.10, I noticed that volume and screen brightness get reset every time Ubuntu starts. Why is this so? And what ways are there to keep brightness and volume levels after rebooting? I have found some scripts that change the screen-brightness at login. But this is not a good solution since login is slower because it seems to wait until the screen brightness is at the level specified by the script. After entering the password I see the screen brightness go down gradually. Only after this is complete (~1 or 2 seconds) does the background disappear and Unity come up. The screenbrightness is not remembered but instead redefined at login. So it gets remembered for the first part of the boot, then set to MAX and then again re-set to normal value by the script. My boot process is as follows: desired brightness: 2 (13,33%) / Max brightness: 15 (100%) Bios / brightness: OK GRUB (violet background color, white text) / brightness: OK Ubuntu loading screen with the dots / brightness: MAX (win7 loads with OK-brightness) User Login / brightness: MAX Unity starts / brightness: OK It seems to be more like a temporary patch than a actual solution. I'm looking for solutions that set the desired brightness permanently and consistently throughout the whole boot-process After updating to 12.04 the behavior is the same. I tried setpci -s 02:00.0 F4.B=XX The value of F4.B is always '0' regardless of what value I try to set it to (tried 0, ff, f, 5, etc) The solution in this answer does not have any noticeable effect: Desktop doesn't remember brightness settings after a reboot The variables at /sys/class/backlight/acpi_video0/ get changed if I use Fn+UP and Fn+DOWN Any help is appreciated. Thanks!

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• Refactor This (Ugly Code)!

  - by Alois Kraus

  Ayende has put on his blog some ugly code to refactor. First and foremost it is nearly impossible to reason about other peoples code without knowing the driving forces behind the current code. It is certainly possible to make it much cleaner when potential sources of errors cannot happen in the first place due to good design. I can see what the intention of the code is but I do not know about every brittle detail if I am allowed to reorder things here and there to simplify things. So I decided to make it much simpler by identifying the different responsibilities of the methods and encapsulate it in different classes. The code we need to refactor seems to deal with a handler after a message has been sent to a message queue. The handler does complete the current transaction if there is any and does handle any errors happening there. If during the the completion of the transaction errors occur the transaction is at least disposed. We can enter the handler already in a faulty state where we try to deliver the complete event in any case and signal a failure event and try to resend the message again to the queue if it was not inside a transaction. All is decorated with many try/catch blocks, duplicated code and some state variables to route the program flow. It is hard to understand and difficult to reason about. In other words: This code is a mess and could be written by me if I was under pressure. Here comes to code we want to refactor:         private void HandleMessageCompletion(                                      Message message,                                      TransactionScope tx,                                      OpenedQueue messageQueue,                                      Exception exception,                                      Action<CurrentMessageInformation, Exception> messageCompleted,                                      Action<CurrentMessageInformation> beforeTransactionCommit)         {             var txDisposed = false;             if (exception == null)             {                 try                 {                     if (tx != null)                     {                         if (beforeTransactionCommit != null)                             beforeTransactionCommit(currentMessageInformation);                         tx.Complete();                         tx.Dispose();                         txDisposed = true;                     }                     try                     {                         if (messageCompleted != null)                             messageCompleted(currentMessageInformation, exception);                     }                     catch (Exception e)                     {                         Trace.TraceError("An error occured when raising the MessageCompleted event, the error will NOT affect the message processing"+ e);                     }                     return;                 }                 catch (Exception e)                 {                     Trace.TraceWarning("Failed to complete transaction, moving to error mode"+ e);                     exception = e;                 }             }             try             {                 if (txDisposed == false && tx != null)                 {                     Trace.TraceWarning("Disposing transaction in error mode");                     tx.Dispose();                 }             }             catch (Exception e)             {                 Trace.TraceWarning("Failed to dispose of transaction in error mode."+ e);             }             if (message == null)                 return;                 try             {                 if (messageCompleted != null)                     messageCompleted(currentMessageInformation, exception);             }             catch (Exception e)             {                 Trace.TraceError("An error occured when raising the MessageCompleted event, the error will NOT affect the message processing"+ e);             }               try             {                 var copy = MessageProcessingFailure;                 if (copy != null)                     copy(currentMessageInformation, exception);             }             catch (Exception moduleException)             {                 Trace.TraceError("Module failed to process message failure: " + exception.Message+                                              moduleException);             }               if (messageQueue.IsTransactional == false)// put the item back in the queue             {                 messageQueue.Send(message);             }         }     You can see quite some processing and handling going on there. Yes this looks like real world code one did put together to make things work and he does not trust his callbacks. I guess these are event handlers which are optional and the delegates were extracted from an event to call them back later when necessary.  Lets see what the author of this code did intend:          private void HandleMessageCompletion(             TransactionHandler transactionHandler,             MessageCompletionHandler handler,             CurrentMessageInformation messageInfo,             ErrorCollector errors             )         {               // commit current pending transaction             transactionHandler.CallHandlerAndCommit(messageInfo, errors);               // We have an error for a null message do not send completion event             if (messageInfo.CurrentMessage == null)                 return;               // Send completion event in any case regardless of errors             handler.OnMessageCompleted(messageInfo, errors);               // put message back if queue is not transactional             transactionHandler.ResendMessageOnError(messageInfo.CurrentMessage, errors);         }   I did not bother to write the intention here again since the code should be pretty self explaining by now. I have used comments to explain the still nontrivial procedure step by step revealing the real intention about all this complex program flow. The original complexity of the problem domain does not go away but by applying the techniques of SRP (Single Responsibility Principle) and some functional style but we can abstract the necessary complexity away in useful abstractions which make it much easier to reason about it. Since most of the method seems to deal with errors I thought it was a good idea to encapsulate the error state of our current message in an ErrorCollector object which stores all exceptions in a list along with a description what the error all was about in the exception itself. We can log it later or not depending on the log level or whatever. It is really just a simple list that encapsulates the current error state.          class ErrorCollector          {              List<Exception> _Errors = new List<Exception>();                public void Add(Exception ex, string description)              {                  ex.Data["Description"] = description;                  _Errors.Add(ex);              }                public Exception Last              {                  get                  {                      return _Errors.LastOrDefault();                  }              }                public bool HasError              {                  get                  {                      return _Errors.Count > 0;                  }              }          }   Since the error state is global we have two choices to store a reference in the other helper objects (TransactionHandler and MessageCompletionHandler)or pass it to the method calls when necessary. I did chose the latter one because a second argument does not hurt and makes it easier to reason about the overall state while the helper objects remain stateless and immutable which makes the helper objects much easier to understand and as a bonus thread safe as well. This does not mean that the stored member variables are stateless or thread safe as well but at least our helper classes are it. Most of the complexity is located the transaction handling I consider as a separate responsibility that I delegate to the TransactionHandler which does nothing if there is no transaction or Call the Before Commit Handler Commit Transaction Dispose Transaction if commit did throw In fact it has a second responsibility to resend the message if the transaction did fail. I did see a good fit there since it deals with transaction failures.          class TransactionHandler          {              TransactionScope _Tx;              Action<CurrentMessageInformation> _BeforeCommit;              OpenedQueue _MessageQueue;                public TransactionHandler(TransactionScope tx, Action<CurrentMessageInformation> beforeCommit, OpenedQueue messageQueue)              {                  _Tx = tx;                  _BeforeCommit = beforeCommit;                  _MessageQueue = messageQueue;              }                public void CallHandlerAndCommit(CurrentMessageInformation currentMessageInfo, ErrorCollector errors)              {                  if (_Tx != null && !errors.HasError)                  {                      try                      {                          if (_BeforeCommit != null)                          {                              _BeforeCommit(currentMessageInfo);                          }                            _Tx.Complete();                          _Tx.Dispose();                      }                      catch (Exception ex)                      {                          errors.Add(ex, "Failed to complete transaction, moving to error mode");                          Trace.TraceWarning("Disposing transaction in error mode");                          try                          {                              _Tx.Dispose();                          }                          catch (Exception ex2)                          {                              errors.Add(ex2, "Failed to dispose of transaction in error mode.");                          }                      }                  }              }                public void ResendMessageOnError(Message message, ErrorCollector errors)              {                  if (errors.HasError && !_MessageQueue.IsTransactional)                  {                      _MessageQueue.Send(message);                  }              }          } If we need to change the handling in the future we have a much easier time to reason about our application flow than before. After we did complete our transaction and called our callback we can call the completion handler which is the main purpose of the HandleMessageCompletion method after all. The responsiblity o the MessageCompletionHandler is to call the completion callback and the failure callback when some error has occurred.            class MessageCompletionHandler          {              Action<CurrentMessageInformation, Exception> _MessageCompletedHandler;              Action<CurrentMessageInformation, Exception> _MessageProcessingFailure;                public MessageCompletionHandler(Action<CurrentMessageInformation, Exception> messageCompletedHandler,                                              Action<CurrentMessageInformation, Exception> messageProcessingFailure)              {                  _MessageCompletedHandler = messageCompletedHandler;                  _MessageProcessingFailure = messageProcessingFailure;              }                  public void OnMessageCompleted(CurrentMessageInformation currentMessageInfo, ErrorCollector errors)              {                  try                  {                      if (_MessageCompletedHandler != null)                      {                          _MessageCompletedHandler(currentMessageInfo, errors.Last);                      }                  }                  catch (Exception ex)                  {                      errors.Add(ex, "An error occured when raising the MessageCompleted event, the error will NOT affect the message processing");                  }                    if (errors.HasError)                  {                      SignalFailedMessage(currentMessageInfo, errors);                  }              }                void SignalFailedMessage(CurrentMessageInformation currentMessageInfo, ErrorCollector errors)              {                  try                  {                      if (_MessageProcessingFailure != null)                          _MessageProcessingFailure(currentMessageInfo, errors.Last);                  }                  catch (Exception moduleException)                  {                      errors.Add(moduleException, "Module failed to process message failure");                  }              }            }   If for some reason I did screw up the logic and we need to call the completion handler from our Transaction handler we can simple add to the CallHandlerAndCommit method a third argument to the MessageCompletionHandler and we are fine again. If the logic becomes even more complex and we need to ensure that the completed event is triggered only once we have now one place the completion handler to capture the state. During this refactoring I simple put things together that belong together and came up with useful abstractions. If you look at the original argument list of the HandleMessageCompletion method I have put many things together:   Original Arguments New Arguments Encapsulate Message message CurrentMessageInformation messageInfo         Message message TransactionScope tx Action<CurrentMessageInformation> beforeTransactionCommit OpenedQueue messageQueue TransactionHandler transactionHandler        TransactionScope tx        OpenedQueue messageQueue        Action<CurrentMessageInformation> beforeTransactionCommit Exception exception,             ErrorCollector errors Action<CurrentMessageInformation, Exception> messageCompleted MessageCompletionHandler handler          Action<CurrentMessageInformation, Exception> messageCompleted          Action<CurrentMessageInformation, Exception> messageProcessingFailure The reason is simple: Put the things that have relationships together and you will find nearly automatically useful abstractions. I hope this makes sense to you. If you see a way to make it even more simple you can show Ayende your improved version as well.

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• My New BDD Style

  - by Liam McLennan

  I have made a change to my code-based BDD style. I start with a scenario such as: Pre-Editing * Given I am a book editor * And some chapters are locked and some are not * When I view the list of chapters for editing * Then I should see some chapters are editable and are not locked * And I should see some chapters are not editable and are locked and I implement it using a modified SpecUnit base class as: [Concern("Chapter Editing")] public class when_pre_editing_a_chapter : BaseSpec { private User i; // other context variables protected override void Given() { i_am_a_book_editor(); some_chapters_are_locked_and_some_are_not(); } protected override void Do() { i_view_the_list_of_chapters_for_editing(); } private void i_am_a_book_editor() { i = new UserBuilder().WithUsername("me").WithRole(UserRole.BookEditor).Build(); } private void some_chapters_are_locked_and_some_are_not() { } private void i_view_the_list_of_chapters_for_editing() { } [Observation] public void should_see_some_chapters_are_editable_and_are_not_locked() { } [Observation] public void should_see_some_chapters_are_not_editable_and_are_locked() { } } and the output from the specunit report tool is: Chapter Editing specifications    1 context, 2 specifications Chapter Editing, when pre editing a chapter    2 specifications should see some chapters are editable and are not locked should see some chapters are not editable and are locked The intent is to provide a clear mapping from story –> scenarios –> bdd tests.

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• How to Watch NCAA March Madness Online

  - by DigitalGeekery

  You’ve filled out your brackets and now you are ready for one of America’s most popular sporting events. But what if you are you stuck at work or away from your TV?  Or your local affiliate is showing a different game? Today we show how to catch all the March Madness online. March Madness on Demand You’ll need a broadband connection, 512 MB RAM or higher, with cookies and Javascript enabled in your browser. March Madness on Demand offers two viewing options, a Standard Player and a High Quality player. The High Quality player is not, unfortunately, high definition. Standard Player Requirements Windows XP/Vista/7 or Mac OS X IE 6+ (We also successfully tested it in Firefox, Chrome, & Opera) Adobe Flash Player 9 or higher High Quality Player Requirements 2.4 GHz Pentium 4 or Intel-based Macintosh Mac OS 10.4.8+ (Intel-based) Windows: XP SP2, Vista, Server 2003, Server 2008, Windows 7 Firefox 1.5+ or IE 6/7/8 Silverlight 3 browser plug-in Watching March Madness on Demand Go to the March Madness on Demand website. (Link below) Check the “Watch in High Quality” section to see if your browser is ready and compatible for the High Quality viewer. If not, you’ll see a message indicating either your browser and system are incompatible… Or that you need to install Silverlight. To install Silverlight, click on the “Get HQ” button and follow the prompts to download and install Silverlight. To launch the player, click the large red “Launch Player” button. At the top of the screen, you’ll see the current and upcoming games. Click on “Watch Now” below to begin watching. At the bottom left, is where you click to watch with the High Quality player. If to many people are watching the High Quality player, you’ll see the following message and have to go back to the Standard Player. At the lower right are volume controls, a “Full Screen” button, and a “Share” button which allows you to share the game you are watching on various social networking sites like Facebook and Twitter. Perhaps most importantly for those who want to steal a bit of viewing time while at work is the “Boss Button” at the top right. Clicking on the “Boss Button” will open a fake Office document so it may appear at first glance like you’re actually doing legitimate work. To return to the game, click anywhere on the screen with your mouse. You’ll be able to catch every single game of the tournament from the first round all the way through the championship with March Madness on Demand. If your computer and Internet connection can handle it, you can even watch multiple games at the same time by opening March Madness on Demand in multiple browser windows. Watch March Madness online Similar Articles Productive Geek Tips Weekend Fun: Watch Television on Your PC with AnyTVWatch NFL Sunday Night Football On Your PCWatch TV On Your PC with FreeZ Online TVGeek Fun: Download Favorite NBC Programs for FreeDitch the RealPlayer Bloat with Real Alternative TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional How to Browse Privately in Firefox Kill Processes Quickly with Process Assassin Need to Come Up with a Good Name? Try Wordoid StockFox puts a Lightweight Stock Ticker in your Statusbar Explore Google Public Data Visually The Ultimate Excel Cheatsheet

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• ODI 11g – How to override SQL at runtime?

  - by David Allan

  Following on from the posting some time back entitled ‘ODI 11g – Simple, Powerful, Flexible’ here we push the envelope even further. Rather than just having the SQL we override defined statically in the interface design we will have it configurable via a variable….at runtime. Imagine you have a well defined interface shape that you want to be fulfilled and that shape can be satisfied from a number of different sources that is what this allows - or the ability for one interface to consume data from many different places using variables. The cool thing about ODI’s reference API and this is that it can be fantastically flexible and useful. When I use the variable as the option value, and I execute the top level scenario that uses this temporary interface I get prompted (or can get prompted to be correct) for the value of the variable. Note I am using the <@=odiRef.getObjectName("L","EMP", "SCOTT","D")@> notation for the table reference, since this is done at runtime, then the context will resolve to the correct table name etc. Each time I execute, I could use a different source provider (obviously some dependencies on KMs/technologies here). For example, the following groovy snippet first executes and the query uses SCOTT model with EMP, the next time it is from BOB model and the datastore OTHERS. m=new Properties(); m.put("DEMO.SQLSTR", "select empno, deptno from <@=odiRef.getObjectName("L","EMP", "SCOTT","D")@>"); s=new StartupParams(m); runtimeAgent.startScenario("TOP", null, s, null, "GLOBAL", 5, null, true); m2=new Properties(); m2.put("DEMO.SQLSTR", "select empno, deptno from <@=odiRef.getObjectName("L","OTHERS", "BOB","D")@>"); s2=new StartupParams(m); runtimeAgent.startScenario("TOP", null, s2, null, "GLOBAL", 5, null, true); You’ll need a patch to 11.1.1.6 for this type of capability, thanks to my ole buddy Ron Gonzalez from the Enterprise Management group for help pushing the envelope!

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• Investigation: Can different combinations of components effect Dataflow performance?

  - by jamiet

  Introduction The Dataflow task is one of the core components (if not the core component) of SQL Server Integration Services (SSIS) and often the most misunderstood. This is not surprising, its an incredibly complicated beast and we’re abstracted away from that complexity via some boxes that go yellow red or green and that have some lines drawn between them. Example dataflow In this blog post I intend to look under that facade and get into some of the nuts and bolts of the Dataflow Task by investigating how the decisions we make when building our packages can affect performance. I will do this by comparing the performance of three dataflows that all have the same input, all produce the same output, but which all operate slightly differently by way of having different transformation components. I also want to use this blog post to challenge a common held opinion that I see perpetuated over and over again on the SSIS forum. That is, that people assume adding components to a dataflow will be detrimental to overall performance. Its not surprising that people think this –it is intuitive to think that more components means more work- however this is not a view that I share. I have always been of the opinion that there are many factors affecting dataflow duration and the number of components is actually one of the less important ones; having said that I have never proven that assertion and that is one reason for this investigation. I have actually seen evidence that some people think dataflow duration is simply a function of number of rows and number of components. I’ll happily call that one out as a myth even without any investigation!  The Setup I have a 2GB datafile which is a list of 4731904 (~4.7million) customer records with various attributes against them and it contains 2 columns that I am going to use for categorisation: [YearlyIncome] [BirthDate] The data file is a SSIS raw format file which I chose to use because it is the quickest way of getting data into a dataflow and given that I am testing the transformations, not the source or destination adapters, I want to minimise external influences as much as possible. In the test I will split the customers according to month of birth (12 of those) and whether or not their yearly income is above or below 50000 (2 of those); in other words I will be splitting them into 24 discrete categories and in order to do it I shall be using different combinations of SSIS’ Conditional Split and Derived Column transformation components. The 24 datapaths that occur will each input to a rowcount component, again because this is the least resource intensive means of terminating a datapath. The test is being carried out on a Dell XPS Studio laptop with a quad core (8 logical Procs) Intel Core i7 at 1.73GHz and Samsung SSD hard drive. Its running SQL Server 2008 R2 on Windows 7. The Variables Here are the three combinations of components that I am going to test:     One Conditional Split - A single Conditional Split component CSPL Split by Month of Birth and income category that will use expressions on [YearlyIncome] & [BirthDate] to send each row to one of 24 outputs. This next screenshot displays the expression logic in use: Derived Column & Conditional Split - A Derived Column component DER Income Category that adds a new column [IncomeCategory] which will contain one of two possible text values {“LessThan50000”,”GreaterThan50000”} and uses [YearlyIncome] to determine which value each row should get. A Conditional Split component CSPL Split by Month of Birth and Income Category then uses that new column in conjunction with [BirthDate] to determine which of the same 24 outputs to send each row to. Put more simply, I am separating the Conditional Split of #1 into a Derived Column and a Conditional Split. The next screenshots display the expression logic in use: DER Income Category         CSPL Split by Month of Birth and Income Category       Three Conditional Splits - A Conditional Split component that produces two outputs based on [YearlyIncome], one for each Income Category. Each of those outputs will go to a further Conditional Split that splits the input into 12 outputs, one for each month of birth (identical logic in each). In this case then I am separating the single Conditional Split of #1 into three Conditional Split components. The next screenshots display the expression logic in use: CSPL Split by Income Category         CSPL Split by Month of Birth 1& 2       Each of these combinations will provide an input to one of the 24 rowcount components, just the same as before. For illustration here is a screenshot of the dataflow containing three Conditional Split components: As you can these dataflows have a fair bit of work to do and remember that they’re doing that work for 4.7million rows. I will execute each dataflow 10 times and use the average for comparison. I foresee three possible outcomes: The dataflow containing just one Conditional Split (i.e. #1) will be quicker There is no significant difference between any of them One of the two dataflows containing multiple transformation components will be quicker Regardless of which of those outcomes come to pass we will have learnt something and that makes this an interesting test to carry out. Note that I will be executing the dataflows using dtexec.exe rather than hitting F5 within BIDS. The Results and Analysis The table below shows all of the executions, 10 for each dataflow. It also shows the average for each along with a standard deviation. All durations are in seconds. I’m pasting a screenshot because I frankly can’t be bothered with the faffing about needed to make a presentable HTML table. It is plain to see from the average that the dataflow containing three conditional splits is significantly faster, the other two taking 43% and 52% longer respectively. This seems strange though, right? Why does the dataflow containing the most components outperform the other two by such a big margin? The answer is actually quite logical when you put some thought into it and I’ll explain that below. Before progressing, a side note. The standard deviation for the “Three Conditional Splits” dataflow is orders of magnitude smaller – indicating that performance for this dataflow can be predicted with much greater confidence too. The Explanation I refer you to the screenshot above that shows how CSPL Split by Month of Birth and salary category in the first dataflow is setup. Observe that there is a case for each combination of Month Of Date and Income Category – 24 in total. These expressions get evaluated in the order that they appear and hence if we assume that Month of Date and Income Category are uniformly distributed in the dataset we can deduce that the expected number of expression evaluations for each row is 12.5 i.e. 1 (the minimum) + 24 (the maximum) divided by 2 = 12.5. Now take a look at the screenshots for the second dataflow. We are doing one expression evaluation in DER Income Category and we have the same 24 cases in CSPL Split by Month of Birth and Income Category as we had before, only the expression differs slightly. In this case then we have 1 + 12.5 = 13.5 expected evaluations for each row – that would account for the slightly longer average execution time for this dataflow. Now onto the third dataflow, the quick one. CSPL Split by Income Category does a maximum of 2 expression evaluations thus the expected number of evaluations per row is 1.5. CSPL Split by Month of Birth 1 & CSPL Split by Month of Birth 2 both have less work to do than the previous Conditional Split components because they only have 12 cases to test for thus the expected number of expression evaluations is 6.5 There are two of them so total expected number of expression evaluations for this dataflow is 6.5 + 6.5 + 1.5 = 14.5. 14.5 is still more than 12.5 & 13.5 though so why is the third dataflow so much quicker? Simple, the conditional expressions in the first two dataflows have two boolean predicates to evaluate – one for Income Category and one for Month of Birth; the expressions in the Conditional Split in the third dataflow however only have one predicate thus they are doing a lot less work. To sum up, the difference in execution times can be attributed to the difference between: MONTH(BirthDate) == 1 && YearlyIncome <= 50000 and MONTH(BirthDate) == 1 In the first two dataflows YearlyIncome <= 50000 gets evaluated an average of 12.5 times for every row whereas in the third dataflow it is evaluated once and once only. Multiply those 11.5 extra operations by 4.7million rows and you get a significant amount of extra CPU cycles – that’s where our duration difference comes from. The Wrap-up The obvious point here is that adding new components to a dataflow isn’t necessarily going to make it go any slower, moreover you may be able to achieve significant improvements by splitting logic over multiple components rather than one. Performance tuning is all about reducing the amount of work that needs to be done and that doesn’t necessarily mean use less components, indeed sometimes you may be able to reduce workload in ways that aren’t immediately obvious as I think I have proven here. Of course there are many variables in play here and your mileage will most definitely vary. I encourage you to download the package and see if you get similar results – let me know in the comments. The package contains all three dataflows plus a fourth dataflow that will create the 2GB raw file for you (you will also need the [AdventureWorksDW2008] sample database from which to source the data); simply disable all dataflows except the one you want to test before executing the package and remember, execute using dtexec, not within BIDS. If you want to explore dataflow performance tuning in more detail then here are some links you might want to check out: Inequality joins, Asynchronous transformations and Lookups Destination Adapter Comparison Don’t turn the dataflow into a cursor SSIS Dataflow – Designing for performance (webinar) Any comments? Let me know! @Jamiet

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• 45° Slopes in a Tile based 2D platformer

  - by xNidhogg

  I want to have simple 45° slopes in my tile based platformer, however I just cant seem to get the algorithm down. Please take a look at the code and video, maybe I'm missing the obvious? //collisionRectangle is the collision rectangle of the player with //origin at the top left and width and height //wantedPosition is the new position the player will be set to. //this is determined elsewhere by checking the bottom center point of the players rect if(_leftSlope || _rightSlope) { //Test bottom center point var calculationPoint = new Vector2(collisionRectangle.Center.X, collisionRectangle.Bottom); //Get the collision rectangle of the tile, origin is top-left Rectangle cellRect = _tileMap.CellWorldRectangle( _tileMap.GetCellByPixel(calculationPoint)); //Calculate the new Y coordinate depending on if its a left or right slope //CellSize = 8 float newY = _leftSlope ? (calculationPoint.X % CellSize) + cellRect.Y : (-1 * (calculationPoint.X % CellSize) - CellSize) + cellRect.Y; //reset variables so we dont jump in here next frame _leftSlope = false; _rightSlope = false; //now change the players Y according to the difference of our calculation wantedPosition.Y += newY - calculationPoint.Y; } Video of what it looks like: http://youtu.be/EKOWgD2muoc

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• Solaris X86 64-bit Assembly Programming

  - by danx

  Solaris X86 64-bit Assembly Programming This is a simple example on writing, compiling, and debugging Solaris 64-bit x86 assembly language with a C program. This is also referred to as "AMD64" assembly. The term "AMD64" is used in an inclusive sense to refer to all X86 64-bit processors, whether AMD Opteron family or Intel 64 processor family. Both run Solaris x86. I'm keeping this example simple mainly to illustrate how everything comes together—compiler, assembler, linker, and debugger when using assembly language. The example I'm using here is a C program that calls an assembly language program passing a C string. The assembly language program takes the C string and calls printf() with it to print the string. AMD64 Register Usage But first let's review the use of AMD64 registers. AMD64 has several 64-bit registers, some special purpose (such as the stack pointer) and others general purpose. By convention, Solaris follows the AMD64 ABI in register usage, which is the same used by Linux, but different from Microsoft Windows in usage (such as which registers are used to pass parameters). This blog will only discuss conventions for Linux and Solaris. The following chart shows how AMD64 registers are used. The first six parameters to a function are passed through registers. If there's more than six parameters, parameter 7 and above are pushed on the stack before calling the function. The stack is also used to save temporary "stack" variables for use by a function. 64-bit Register Usage %rip Instruction Pointer points to the current instruction %rsp Stack Pointer %rbp Frame Pointer (saved stack pointer pointing to parameters on stack) %rdi Function Parameter 1 %rsi Function Parameter 2 %rdx Function Parameter 3 %rcx Function Parameter 4 %r8 Function Parameter 5 %r9 Function Parameter 6 %rax Function return value %r10, %r11 Temporary registers (need not be saved before used) %rbx, %r12, %r13, %r14, %r15 Temporary registers, but must be saved before use and restored before returning from the current function (usually with the push and pop instructions). 32-, 16-, and 8-bit registers To access the lower 32-, 16-, or 8-bits of a 64-bit register use the following: 64-bit register Least significant 32-bits Least significant 16-bits Least significant 8-bits %rax%eax%ax%al %rbx%ebx%bx%bl %rcx%ecx%cx%cl %rdx%edx%dx%dl %rsi%esi%si%sil %rdi%edi%di%axl %rbp%ebp%bp%bp %rsp%esp%sp%spl %r9%r9d%r9w%r9b %r10%r10d%r10w%r10b %r11%r11d%r11w%r11b %r12%r12d%r12w%r12b %r13%r13d%r13w%r13b %r14%r14d%r14w%r14b %r15%r15d%r15w%r15b %r16%r16d%r16w%r16b There's other registers present, such as the 64-bit %mm registers, 128-bit %xmm registers, 256-bit %ymm registers, and 512-bit %zmm registers. Except for %mm registers, these registers may not present on older AMD64 processors. Assembly Source The following is the source for a C program, helloas1.c, that calls an assembly function, hello_asm(). $ cat helloas1.c extern void hello_asm(char *s); int main(void) { hello_asm("Hello, World!"); } The assembly function called above, hello_asm(), is defined below. $ cat helloas2.s /* * helloas2.s * To build: * cc -m64 -o helloas2-cpp.s -D_ASM -E helloas2.s * cc -m64 -c -o helloas2.o helloas2-cpp.s */ #if defined(lint) || defined(__lint) /* ARGSUSED */ void hello_asm(char *s) { } #else /* lint */ #include <sys/asm_linkage.h> .extern printf ENTRY_NP(hello_asm) // Setup printf parameters on stack mov %rdi, %rsi // P2 (%rsi) is string variable lea .printf_string, %rdi // P1 (%rdi) is printf format string call printf ret SET_SIZE(hello_asm) // Read-only data .text .align 16 .type .printf_string, @object .printf_string: .ascii "The string is: %s.\n\0" #endif /* lint || __lint */ In the assembly source above, the C skeleton code under "#if defined(lint)" is optionally used for lint to check the interfaces with your C program--very useful to catch nasty interface bugs. The "asm_linkage.h" file includes some handy macros useful for assembly, such as ENTRY_NP(), used to define a program entry point, and SET_SIZE(), used to set the function size in the symbol table. The function hello_asm calls C function printf() by passing two parameters, Parameter 1 (P1) is a printf format string, and P2 is a string variable. The function begins by moving %rdi, which contains Parameter 1 (P1) passed hello_asm, to printf()'s P2, %rsi. Then it sets printf's P1, the format string, by loading the address the address of the format string in %rdi, P1. Finally it calls printf. After returning from printf, the hello_asm function returns itself. Larger, more complex assembly functions usually do more setup than the example above. If a function is returning a value, it would set %rax to the return value. Also, it's typical for a function to save the %rbp and %rsp registers of the calling function and to restore these registers before returning. %rsp contains the stack pointer and %rbp contains the frame pointer. Here is the typical function setup and return sequence for a function: ENTRY_NP(sample_assembly_function) push %rbp // save frame pointer on stack mov %rsp, %rbp // save stack pointer in frame pointer xor %rax, %r4ax // set function return value to 0. mov %rbp, %rsp // restore stack pointer pop %rbp // restore frame pointer ret // return to calling function SET_SIZE(sample_assembly_function) Compiling and Running Assembly Use the Solaris cc command to compile both C and assembly source, and to pre-process assembly source. You can also use GNU gcc instead of cc to compile, if you prefer. The "-m64" option tells the compiler to compile in 64-bit address mode (instead of 32-bit). $ cc -m64 -o helloas2-cpp.s -D_ASM -E helloas2.s $ cc -m64 -c -o helloas2.o helloas2-cpp.s $ cc -m64 -c helloas1.c $ cc -m64 -o hello-asm helloas1.o helloas2.o $ file hello-asm helloas1.o helloas2.o hello-asm: ELF 64-bit LSB executable AMD64 Version 1 [SSE FXSR FPU], dynamically linked, not stripped helloas1.o: ELF 64-bit LSB relocatable AMD64 Version 1 helloas2.o: ELF 64-bit LSB relocatable AMD64 Version 1 $ hello-asm The string is: Hello, World!. Debugging Assembly with MDB MDB is the Solaris system debugger. It can also be used to debug user programs, including assembly and C. The following example runs the above program, hello-asm, under control of the debugger. In the example below I load the program, set a breakpoint at the assembly function hello_asm, display the registers and the first parameter, step through the assembly function, and continue execution. $ mdb hello-asm # Start the debugger > hello_asm:b # Set a breakpoint > ::run # Run the program under the debugger mdb: stop at hello_asm mdb: target stopped at: hello_asm: movq %rdi,%rsi > $C # display function stack ffff80ffbffff6e0 hello_asm() ffff80ffbffff6f0 0x400adc() > $r # display registers %rax = 0x0000000000000000 %r8 = 0x0000000000000000 %rbx = 0xffff80ffbf7f8e70 %r9 = 0x0000000000000000 %rcx = 0x0000000000000000 %r10 = 0x0000000000000000 %rdx = 0xffff80ffbffff718 %r11 = 0xffff80ffbf537db8 %rsi = 0xffff80ffbffff708 %r12 = 0x0000000000000000 %rdi = 0x0000000000400cf8 %r13 = 0x0000000000000000 %r14 = 0x0000000000000000 %r15 = 0x0000000000000000 %cs = 0x0053 %fs = 0x0000 %gs = 0x0000 %ds = 0x0000 %es = 0x0000 %ss = 0x004b %rip = 0x0000000000400c70 hello_asm %rbp = 0xffff80ffbffff6e0 %rsp = 0xffff80ffbffff6c8 %rflags = 0x00000282 id=0 vip=0 vif=0 ac=0 vm=0 rf=0 nt=0 iopl=0x0 status=<of,df,IF,tf,SF,zf,af,pf,cf> %gsbase = 0x0000000000000000 %fsbase = 0xffff80ffbf782a40 %trapno = 0x3 %err = 0x0 > ::dis # disassemble the current instructions hello_asm: movq %rdi,%rsi hello_asm+3: leaq 0x400c90,%rdi hello_asm+0xb: call -0x220 <PLT:printf> hello_asm+0x10: ret 0x400c81: nop 0x400c85: nop 0x400c88: nop 0x400c8c: nop 0x400c90: pushq %rsp 0x400c91: pushq $0x74732065 0x400c96: jb +0x69 <0x400d01> > 0x0000000000400cf8/S # %rdi contains Parameter 1 0x400cf8: Hello, World! > [ # Step and execute 1 instruction mdb: target stopped at: hello_asm+3: leaq 0x400c90,%rdi > [ mdb: target stopped at: hello_asm+0xb: call -0x220 <PLT:printf> > [ The string is: Hello, World!. mdb: target stopped at: hello_asm+0x10: ret > [ mdb: target stopped at: main+0x19: movl $0x0,-0x4(%rbp) > :c # continue program execution mdb: target has terminated > $q # quit the MDB debugger $ In the example above, at the start of function hello_asm(), I display the stack contents with "$C", display the registers contents with "$r", then disassemble the current function with "::dis". The first function parameter, which is a C string, is passed by reference with the string address in %rdi (see the register usage chart above). The address is 0x400cf8, so I print the value of the string with the "/S" MDB command: "0x0000000000400cf8/S". I can also print the contents at an address in several other formats. Here's a few popular formats. For more, see the mdb(1) man page for details. address/S C string address/C ASCII character (1 byte) address/E unsigned decimal (8 bytes) address/U unsigned decimal (4 bytes) address/D signed decimal (4 bytes) address/J hexadecimal (8 bytes) address/X hexadecimal (4 bytes) address/B hexadecimal (1 bytes) address/K pointer in hexadecimal (4 or 8 bytes) address/I disassembled instruction Finally, I step through each machine instruction with the "[" command, which steps over functions. If I wanted to enter a function, I would use the "]" command. Then I continue program execution with ":c", which continues until the program terminates. MDB Basic Cheat Sheet Here's a brief cheat sheet of some of the more common MDB commands useful for assembly debugging. There's an entire set of macros and more powerful commands, especially some for debugging the Solaris kernel, but that's beyond the scope of this example. $C Display function stack with pointers $c Display function stack $e Display external function names $v Display non-zero variables and registers $r Display registers ::fpregs Display floating point (or "media" registers). Includes %st, %xmm, and %ymm registers. ::status Display program status ::run Run the program (followed by optional command line parameters) $q Quit the debugger address:b Set a breakpoint address:d Delete a breakpoint $b Display breakpoints :c Continue program execution after a breakpoint [ Step 1 instruction, but step over function calls ] Step 1 instruction address::dis Disassemble instructions at an address ::events Display events Further Information "Assembly Language Techniques for Oracle Solaris on x86 Platforms" by Paul Lowik (2004). Good tutorial on Solaris x86 optimization with assembly. The Solaris Operating System on x86 Platforms An excellent, detailed tutorial on X86 architecture, with Solaris specifics. By an ex-Sun employee, Frank Hofmann (2005). "AMD64 ABI Features", Solaris 64-bit Developer's Guide contains rules on data types and register usage for Intel 64/AMD64-class processors. (available at docs.oracle.com) Solaris X86 Assembly Language Reference Manual (available at docs.oracle.com) SPARC Assembly Language Reference Manual (available at docs.oracle.com) System V Application Binary Interface (2003) defines the AMD64 ABI for UNIX-class operating systems, including Solaris, Linux, and BSD. Google for it—the original website is gone. cc(1), gcc(1), and mdb(1) man pages.

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• Pass Extra Parameters to JavaScript Callback Function

  - by BRADINO

  Here is a simple example of a function that takes a callback function as a parameter. query.send(handleQueryResponse); function handleQueryResponse(response){      alert('Processing...'); } If you wanted to pass extra variables to the callback function, you can do it like this. var param1 = 'something'; var param2 ='something else'; query.send(function(response) { handleQueryResponse(response, param1, param2) }); function handleQueryResponse(response,param1,param2){      alert('Processing...');      alert(param1);      alert(param2); }

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