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  • CodePlex Daily Summary for Saturday, March 20, 2010

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

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  • MySQL Cluster 7.2: Over 8x Higher Performance than Cluster 7.1

    - by Mat Keep
    0 0 1 893 5092 Homework 42 11 5974 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} Summary The scalability enhancements delivered by extensions to multi-threaded data nodes enables MySQL Cluster 7.2 to deliver over 8x higher performance than the previous MySQL Cluster 7.1 release on a recent benchmark What’s New in MySQL Cluster 7.2 MySQL Cluster 7.2 was released as GA (Generally Available) in February 2012, delivering many enhancements to performance on complex queries, new NoSQL Key / Value API, cross-data center replication and ease-of-use. These enhancements are summarized in the Figure below, and detailed in the MySQL Cluster New Features whitepaper Figure 1: Next Generation Web Services, Cross Data Center Replication and Ease-of-Use Once of the key enhancements delivered in MySQL Cluster 7.2 is extensions made to the multi-threading processes of the data nodes. Multi-Threaded Data Node Extensions The MySQL Cluster 7.2 data node is now functionally divided into seven thread types: 1) Local Data Manager threads (ldm). Note – these are sometimes also called LQH threads. 2) Transaction Coordinator threads (tc) 3) Asynchronous Replication threads (rep) 4) Schema Management threads (main) 5) Network receiver threads (recv) 6) Network send threads (send) 7) IO threads Each of these thread types are discussed in more detail below. MySQL Cluster 7.2 increases the maximum number of LDM threads from 4 to 16. The LDM contains the actual data, which means that when using 16 threads the data is more heavily partitioned (this is automatic in MySQL Cluster). Each LDM thread maintains its own set of data partitions, index partitions and REDO log. The number of LDM partitions per data node is not dynamically configurable, but it is possible, however, to map more than one partition onto each LDM thread, providing flexibility in modifying the number of LDM threads. The TC domain stores the state of in-flight transactions. This means that every new transaction can easily be assigned to a new TC thread. Testing has shown that in most cases 1 TC thread per 2 LDM threads is sufficient, and in many cases even 1 TC thread per 4 LDM threads is also acceptable. Testing also demonstrated that in some instances where the workload needed to sustain very high update loads it is necessary to configure 3 to 4 TC threads per 4 LDM threads. In the previous MySQL Cluster 7.1 release, only one TC thread was available. This limit has been increased to 16 TC threads in MySQL Cluster 7.2. The TC domain also manages the Adaptive Query Localization functionality introduced in MySQL Cluster 7.2 that significantly enhanced complex query performance by pushing JOIN operations down to the data nodes. Asynchronous Replication was separated into its own thread with the release of MySQL Cluster 7.1, and has not been modified in the latest 7.2 release. To scale the number of TC threads, it was necessary to separate the Schema Management domain from the TC domain. The schema management thread has little load, so is implemented with a single thread. The Network receiver domain was bound to 1 thread in MySQL Cluster 7.1. With the increase of threads in MySQL Cluster 7.2 it is also necessary to increase the number of recv threads to 8. This enables each receive thread to service one or more sockets used to communicate with other nodes the Cluster. The Network send thread is a new thread type introduced in MySQL Cluster 7.2. Previously other threads handled the sending operations themselves, which can provide for lower latency. To achieve highest throughput however, it has been necessary to create dedicated send threads, of which 8 can be configured. It is still possible to configure MySQL Cluster 7.2 to a legacy mode that does not use any of the send threads – useful for those workloads that are most sensitive to latency. The IO Thread is the final thread type and there have been no changes to this domain in MySQL Cluster 7.2. Multiple IO threads were already available, which could be configured to either one thread per open file, or to a fixed number of IO threads that handle the IO traffic. Except when using compression on disk, the IO threads typically have a very light load. Benchmarking the Scalability Enhancements The scalability enhancements discussed above have made it possible to scale CPU usage of each data node to more than 5x of that possible in MySQL Cluster 7.1. In addition, a number of bottlenecks have been removed, making it possible to scale data node performance by even more than 5x. Figure 2: MySQL Cluster 7.2 Delivers 8.4x Higher Performance than 7.1 The flexAsynch benchmark was used to compare MySQL Cluster 7.2 performance to 7.1 across an 8-node Intel Xeon x5670-based cluster of dual socket commodity servers (6 cores each). As the results demonstrate, MySQL Cluster 7.2 delivers over 8x higher performance per data nodes than MySQL Cluster 7.1. More details of this and other benchmarks will be published in a new whitepaper – coming soon, so stay tuned! In a following blog post, I’ll provide recommendations on optimum thread configurations for different types of server processor. You can also learn more from the Best Practices Guide to Optimizing Performance of MySQL Cluster Conclusion MySQL Cluster has achieved a range of impressive benchmark results, and set in context with the previous 7.1 release, is able to deliver over 8x higher performance per node. As a result, the multi-threaded data node extensions not only serve to increase performance of MySQL Cluster, they also enable users to achieve significantly improved levels of utilization from current and future generations of massively multi-core, multi-thread processor designs.

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  • Exploring the Excel Services REST API

    - by jamiet
    Over the last few years Analysis Services guru Chris Webb and I have been on something of a crusade to enable better access to data that is locked up in countless Excel workbooks that litter the hard drives of enterprise PCs. The most prominent manifestation of that crusade up to now has been a forum thread that Chris began on Microsoft Answers entitled Excel Web App API? Chris began that thread with: I was wondering whether there was an API for the Excel Web App? Specifically, I was wondering if it was possible (or if it will be possible in the future) to expose data in a spreadsheet in the Excel Web App as an OData feed, in the way that it is possible with Excel Services? Up to recently the last 10 words of that paragraph "in the way that it is possible with Excel Services" had completely washed over me however a comment on my recent blog post Thoughts on ExcelMashup.com (and a rant) by Josh Booker in which Josh said: Excel Services is a service application built for sharepoint 2010 which exposes a REST API for excel documents. We're looking forward to pros like you giving it a try now that Office365 makes sharepoint more easily accessible.  Can't wait for your future blog about using REST API to load data from Excel on Offce 365 in SSIS. made me think that perhaps the Excel Services REST API is something I should be looking into and indeed that is what I have been doing over the past few days. And you know what? I'm rather impressed with some of what Excel Services' REST API has to offer. Unfortunately Excel Services' REST API also has one debilitating aspect that renders this blog post much less useful than it otherwise would be; namely that it is not publicly available from the Excel Web App on SkyDrive. Therefore all I can do in this blog post is show you screenshots of what the REST API provides in Sharepoint rather than linking you directly to those REST resources; that's a great shame because one of the benefits of a REST API is that it is easily and ubiquitously demonstrable from a web browser. Instead I am hosting a workbook on Sharepoint in Office 365 because that does include Excel Services' REST API but, again, all I can do is show you screenshots. N.B. If anyone out there knows how to make Office-365-hosted spreadsheets publicly-accessible (i.e. without requiring a username/password) please do let me know (because knowing which forum on which to ask the question is an exercise in futility). In order to demonstrate Excel Services' REST API I needed some decent data and for that I used the World Tourism Organization Statistics Database and Yearbook - United Nations World Tourism Organization dataset hosted on Azure Datamarket (its free, by the way); this dataset "provides comprehensive information on international tourism worldwide and offers a selection of the latest available statistics on international tourist arrivals, tourism receipts and expenditure" and you can explore the data for yourself here. If you want to play along at home by viewing the data as it exists in Excel then it can be viewed here. Let's dive in.   The root of Excel Services' REST API is the model resource which resides at: http://server/_vti_bin/ExcelRest.aspx/Documents/TourismExpenditureInMillionsOfUSD.xlsx/model Note that this is true for every workbook hosted in a Sharepoint document library - each Excel workbook is a RESTful resource. (Update: Mark Stacey on Twitter tells me that "It's turned off by default in onpremise Sharepoint (1 tickbox to turn on though)". Thanks Mark!) The data is provided as an ATOM feed but I have Firefox's feed reading ability turned on so you don't see the underlying XML goo. As you can see there are four top level resources, Ranges, Charts, Tables and PivotTables; exploring one of those resources is where things get interesting. Let's take a look at the Tables Resource: http://server/_vti_bin/ExcelRest.aspx/Documents/TourismExpenditureInMillionsOfUSD.xlsx/model/Tables Our workbook contains only one table, called ‘Table1’ (to reiterate, you can explore this table yourself here). Viewing that table via the REST API is pretty easy, we simply append the name of the table onto our previous URI: http://server/_vti_bin/ExcelRest.aspx/Documents/TourismExpenditureInMillionsOfUSD.xlsx/model/Tables('Table1') As you can see, that quite simply gives us a representation of the data in that table. What you cannot see from this screenshot is that this is pure HTML that is being served up; that is all well and good but actually we can do more interesting things. If we specify that the data should be returned not as HTML but as: http://server/_vti_bin/ExcelRest.aspx/Documents/TourismExpenditureInMillionsOfUSD.xlsx/model/Tables('Table1')?$format=image then that data comes back as a pure image and can be used in any web page where you would ordinarily use images. This is the thing that I really like about Excel Services’ REST API – we can embed an image in any web page but instead of being a copy of the data, that image is actually live – if the underlying data in the workbook were to change then hitting refresh will show a new image. Pretty cool, no? The same is true of any Charts or Pivot Tables in your workbook - those can be embedded as images too and if the underlying data changes, boom, the image in your web page changes too. There is a lot of data in the workbook so the image returned by that previous URI is too large to show here so instead let’s take a look at a different resource, this time a range: http://server/_vti_bin/ExcelRest.aspx/Documents/TourismExpenditureInMillionsOfUSD.xlsx/model/Ranges('Data!A1|C15') That URI returns cells A1 to C15 from a worksheet called “Data”: And if we ask for that as an image again: http://server/_vti_bin/ExcelRest.aspx/Documents/TourismExpenditureInMillionsOfUSD.xlsx/model/Ranges('Data!A1|C15')?$format=image Were this image resource not behind a username/password then this would be a live image of the data in the workbook as opposed to one that I had to copy and upload elsewhere. Nonetheless I hope this little wrinkle doesn't detract from the inate value of what I am trying to articulate here; that an existing image in a web page can be changed on-the-fly simply by inserting some data into an Excel workbook. I for one think that that is very cool indeed! I think that's enough in the way of demo for now as this shows what is possible using Excel Services' REST API. Of course, not all features work quite how I would like and here is a bulleted list of some of my more negative feedback: The URIs are pig-ugly. Are "_vti_bin" & "ExcelRest.aspx" really necessary as part of the URI? Would this not be better: http://server/Documents/TourismExpenditureInMillionsOfUSD.xlsx/Model/Tables(‘Table1’) That URI provides the necessary addressability and is a lot easier to remember. Discoverability of these resources is not easy, we essentially have to handcrank a URI ourselves. Take the example of embedding a chart into a blog post - would it not be better if I could browse first through the document library to an Excel workbook and THEN through the workbook to the chart/range/table that I am interested in? Call it a wizard if you like. That would be really cool and would, I am sure, promote this feature and cut down on the copy-and-paste disease that the REST API is meant to alleviate. The resources that I demonstrated can be returned as feeds as well as images or HTML simply by changing the format parameter to ?$format=atom however for some inexplicable reason they don't return OData and no-one on the Excel Services team can tell me why (believe me, I have asked). $format is an OData parameter however other useful parameters such as $top and $filter are not supported. It would be nice if they were. Although I haven't demonstrated it here Excel Services' REST API does provide a makeshift way of altering the data by changing the value of specific cells however what it does not allow you to do is add new data into the workbook. Google Docs allows this and was one of the motivating factors for Chris Webb's forum post that I linked to above. None of this works for Excel workbooks hosted on SkyDrive This blog post is as long as it needs to be for a short introduction so I'll stop now. If you want to know more than I recommend checking out a few links: Excel Services REST API documentation on MSDNSo what does REST on Excel Services look like??? by Shahar PrishExcel Services in SharePoint 2010 REST API Syntax by Christian Stich. Any thoughts? Let's hear them in the comments section below! @Jamiet 

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  • C# Performance Pitfall – Interop Scenarios Change the Rules

    - by Reed
    C# and .NET, overall, really do have fantastic performance in my opinion.  That being said, the performance characteristics dramatically differ from native programming, and take some relearning if you’re used to doing performance optimization in most other languages, especially C, C++, and similar.  However, there are times when revisiting tricks learned in native code play a critical role in performance optimization in C#. I recently ran across a nasty scenario that illustrated to me how dangerous following any fixed rules for optimization can be… The rules in C# when optimizing code are very different than C or C++.  Often, they’re exactly backwards.  For example, in C and C++, lifting a variable out of loops in order to avoid memory allocations often can have huge advantages.  If some function within a call graph is allocating memory dynamically, and that gets called in a loop, it can dramatically slow down a routine. This can be a tricky bottleneck to track down, even with a profiler.  Looking at the memory allocation graph is usually the key for spotting this routine, as it’s often “hidden” deep in call graph.  For example, while optimizing some of my scientific routines, I ran into a situation where I had a loop similar to: for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i]); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This loop was at a fairly high level in the call graph, and often could take many hours to complete, depending on the input data.  As such, any performance optimization we could achieve would be greatly appreciated by our users. After a fair bit of profiling, I noticed that a couple of function calls down the call graph (inside of ProcessElement), there was some code that effectively was doing: // Allocate some data required DataStructure* data = new DataStructure(num); // Call into a subroutine that passed around and manipulated this data highly CallSubroutine(data); // Read and use some values from here double values = data->Foo; // Cleanup delete data; // ... return bar; Normally, if “DataStructure” was a simple data type, I could just allocate it on the stack.  However, it’s constructor, internally, allocated it’s own memory using new, so this wouldn’t eliminate the problem.  In this case, however, I could change the call signatures to allow the pointer to the data structure to be passed into ProcessElement and through the call graph, allowing the inner routine to reuse the same “data” memory instead of allocating.  At the highest level, my code effectively changed to something like: DataStructure* data = new DataStructure(numberToProcess); for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i], data); } delete data; Granted, this dramatically reduced the maintainability of the code, so it wasn’t something I wanted to do unless there was a significant benefit.  In this case, after profiling the new version, I found that it increased the overall performance dramatically – my main test case went from 35 minutes runtime down to 21 minutes.  This was such a significant improvement, I felt it was worth the reduction in maintainability. In C and C++, it’s generally a good idea (for performance) to: Reduce the number of memory allocations as much as possible, Use fewer, larger memory allocations instead of many smaller ones, and Allocate as high up the call stack as possible, and reuse memory I’ve seen many people try to make similar optimizations in C# code.  For good or bad, this is typically not a good idea.  The garbage collector in .NET completely changes the rules here. In C#, reallocating memory in a loop is not always a bad idea.  In this scenario, for example, I may have been much better off leaving the original code alone.  The reason for this is the garbage collector.  The GC in .NET is incredibly effective, and leaving the allocation deep inside the call stack has some huge advantages.  First and foremost, it tends to make the code more maintainable – passing around object references tends to couple the methods together more than necessary, and overall increase the complexity of the code.  This is something that should be avoided unless there is a significant reason.  Second, (unlike C and C++) memory allocation of a single object in C# is normally cheap and fast.  Finally, and most critically, there is a large advantage to having short lived objects.  If you lift a variable out of the loop and reuse the memory, its much more likely that object will get promoted to Gen1 (or worse, Gen2).  This can cause expensive compaction operations to be required, and also lead to (at least temporary) memory fragmentation as well as more costly collections later. As such, I’ve found that it’s often (though not always) faster to leave memory allocations where you’d naturally place them – deep inside of the call graph, inside of the loops.  This causes the objects to stay very short lived, which in turn increases the efficiency of the garbage collector, and can dramatically improve the overall performance of the routine as a whole. In C#, I tend to: Keep variable declarations in the tightest scope possible Declare and allocate objects at usage While this tends to cause some of the same goals (reducing unnecessary allocations, etc), the goal here is a bit different – it’s about keeping the objects rooted for as little time as possible in order to (attempt) to keep them completely in Gen0, or worst case, Gen1.  It also has the huge advantage of keeping the code very maintainable – objects are used and “released” as soon as possible, which keeps the code very clean.  It does, however, often have the side effect of causing more allocations to occur, but keeping the objects rooted for a much shorter time. Now – nowhere here am I suggesting that these rules are hard, fast rules that are always true.  That being said, my time spent optimizing over the years encourages me to naturally write code that follows the above guidelines, then profile and adjust as necessary.  In my current project, however, I ran across one of those nasty little pitfalls that’s something to keep in mind – interop changes the rules. In this case, I was dealing with an API that, internally, used some COM objects.  In this case, these COM objects were leading to native allocations (most likely C++) occurring in a loop deep in my call graph.  Even though I was writing nice, clean managed code, the normal managed code rules for performance no longer apply.  After profiling to find the bottleneck in my code, I realized that my inner loop, a innocuous looking block of C# code, was effectively causing a set of native memory allocations in every iteration.  This required going back to a “native programming” mindset for optimization.  Lifting these variables and reusing them took a 1:10 routine down to 0:20 – again, a very worthwhile improvement. Overall, the lessons here are: Always profile if you suspect a performance problem – don’t assume any rule is correct, or any code is efficient just because it looks like it should be Remember to check memory allocations when profiling, not just CPU cycles Interop scenarios often cause managed code to act very differently than “normal” managed code. Native code can be hidden very cleverly inside of managed wrappers

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  • Why Is Vertical Resolution Monitor Resolution so Often a Multiple of 360?

    - by Jason Fitzpatrick
    Stare at a list of monitor resolutions long enough and you might notice a pattern: many of the vertical resolutions, especially those of gaming or multimedia displays, are multiples of 360 (720, 1080, 1440, etc.) But why exactly is this the case? Is it arbitrary or is there something more at work? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Trojandestroy recently noticed something about his display interface and needs answers: YouTube recently added 1440p functionality, and for the first time I realized that all (most?) vertical resolutions are multiples of 360. Is this just because the smallest common resolution is 480×360, and it’s convenient to use multiples? (Not doubting that multiples are convenient.) And/or was that the first viewable/conveniently sized resolution, so hardware (TVs, monitors, etc) grew with 360 in mind? Taking it further, why not have a square resolution? Or something else unusual? (Assuming it’s usual enough that it’s viewable). Is it merely a pleasing-the-eye situation? So why have the display be a multiple of 360? The Answer SuperUser contributor User26129 offers us not just an answer as to why the numerical pattern exists but a history of screen design in the process: Alright, there are a couple of questions and a lot of factors here. Resolutions are a really interesting field of psychooptics meeting marketing. First of all, why are the vertical resolutions on youtube multiples of 360. This is of course just arbitrary, there is no real reason this is the case. The reason is that resolution here is not the limiting factor for Youtube videos – bandwidth is. Youtube has to re-encode every video that is uploaded a couple of times, and tries to use as little re-encoding formats/bitrates/resolutions as possible to cover all the different use cases. For low-res mobile devices they have 360×240, for higher res mobile there’s 480p, and for the computer crowd there is 360p for 2xISDN/multiuser landlines, 720p for DSL and 1080p for higher speed internet. For a while there were some other codecs than h.264, but these are slowly being phased out with h.264 having essentially ‘won’ the format war and all computers being outfitted with hardware codecs for this. Now, there is some interesting psychooptics going on as well. As I said: resolution isn’t everything. 720p with really strong compression can and will look worse than 240p at a very high bitrate. But on the other side of the spectrum: throwing more bits at a certain resolution doesn’t magically make it better beyond some point. There is an optimum here, which of course depends on both resolution and codec. In general: the optimal bitrate is actually proportional to the resolution. So the next question is: what kind of resolution steps make sense? Apparently, people need about a 2x increase in resolution to really see (and prefer) a marked difference. Anything less than that and many people will simply not bother with the higher bitrates, they’d rather use their bandwidth for other stuff. This has been researched quite a long time ago and is the big reason why we went from 720×576 (415kpix) to 1280×720 (922kpix), and then again from 1280×720 to 1920×1080 (2MP). Stuff in between is not a viable optimization target. And again, 1440P is about 3.7MP, another ~2x increase over HD. You will see a difference there. 4K is the next step after that. Next up is that magical number of 360 vertical pixels. Actually, the magic number is 120 or 128. All resolutions are some kind of multiple of 120 pixels nowadays, back in the day they used to be multiples of 128. This is something that just grew out of LCD panel industry. LCD panels use what are called line drivers, little chips that sit on the sides of your LCD screen that control how bright each subpixel is. Because historically, for reasons I don’t really know for sure, probably memory constraints, these multiple-of-128 or multiple-of-120 resolutions already existed, the industry standard line drivers became drivers with 360 line outputs (1 per subpixel). If you would tear down your 1920×1080 screen, I would be putting money on there being 16 line drivers on the top/bottom and 9 on one of the sides. Oh hey, that’s 16:9. Guess how obvious that resolution choice was back when 16:9 was ‘invented’. Then there’s the issue of aspect ratio. This is really a completely different field of psychology, but it boils down to: historically, people have believed and measured that we have a sort of wide-screen view of the world. Naturally, people believed that the most natural representation of data on a screen would be in a wide-screen view, and this is where the great anamorphic revolution of the ’60s came from when films were shot in ever wider aspect ratios. Since then, this kind of knowledge has been refined and mostly debunked. Yes, we do have a wide-angle view, but the area where we can actually see sharply – the center of our vision – is fairly round. Slightly elliptical and squashed, but not really more than about 4:3 or 3:2. So for detailed viewing, for instance for reading text on a screen, you can utilize most of your detail vision by employing an almost-square screen, a bit like the screens up to the mid-2000s. However, again this is not how marketing took it. Computers in ye olden days were used mostly for productivity and detailed work, but as they commoditized and as the computer as media consumption device evolved, people didn’t necessarily use their computer for work most of the time. They used it to watch media content: movies, television series and photos. And for that kind of viewing, you get the most ‘immersion factor’ if the screen fills as much of your vision (including your peripheral vision) as possible. Which means widescreen. But there’s more marketing still. When detail work was still an important factor, people cared about resolution. As many pixels as possible on the screen. SGI was selling almost-4K CRTs! The most optimal way to get the maximum amount of pixels out of a glass substrate is to cut it as square as possible. 1:1 or 4:3 screens have the most pixels per diagonal inch. But with displays becoming more consumery, inch-size became more important, not amount of pixels. And this is a completely different optimization target. To get the most diagonal inches out of a substrate, you want to make the screen as wide as possible. First we got 16:10, then 16:9 and there have been moderately successful panel manufacturers making 22:9 and 2:1 screens (like Philips). Even though pixel density and absolute resolution went down for a couple of years, inch-sizes went up and that’s what sold. Why buy a 19″ 1280×1024 when you can buy a 21″ 1366×768? Eh… I think that about covers all the major aspects here. There’s more of course; bandwidth limits of HDMI, DVI, DP and of course VGA played a role, and if you go back to the pre-2000s, graphics memory, in-computer bandwdith and simply the limits of commercially available RAMDACs played an important role. But for today’s considerations, this is about all you need to know. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

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  • WIF using SAML 2 protocol / Federate AD FS 2.0 with CAS

    - by spa
    I'am are trying to implement a Web SSO with claim based identity using WIF and AD FS 2.0 right now. Right now I have a existing ASP.Net application which delegates authentification to the AD FS 2.0 server and trust issued security tokens. That works just fine. However, in the organization there is an existing JA-SIG Central Authentication Service (CAS) server which supports the SAML 2 protocol. I would like to replace AD FS 2.0 with the existing CAS service. In my understanding WIF uses WS-Federation, which is like a container around a SAML token. Is it possible to use the plain SAML 2 protocol and it's bindings (redirect or POST)? If that is not possible (as I guess), a second alternative might be to use federate identity and federate AD FS 2.0 with CAS. Is that possible? There is little to no information about that on the web. Thanks :-)

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  • How to export skype history

    - by Peter Štibraný
    Is it possible to export skype chat history into some readable plain-text format? (txt, xml, html) Alternatively, is it possible to backup/restore skype chat history? (I wouldn't mind backup to Gmail, or to readable plain-text format). I have found numerous tools on the internet and even tried some of them, but they don't seem to work as advertised :-( Please answer only if you have good experience with some tool. I'm using Skype v4.

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  • Fancy dynamic list in Android: TableLayout vs ListView

    - by Ralkie
    There is a requirement to have not-so-trivial dynamic list, each record of which consists of several columns (texts, buttons). It should look something like: Text11 Text12 Button1 Button2 Text21 Text22 Button1 Button2 ... At first obvious way to accomplish that seemed to be TableLayout. I was expecting to have layout/styling data specified in res/layout/*.xml and to populate it with some dataset from java code (as with ListView, for which its possible to specify TextView of item in *.xml and bind it to some array using ArrayAdapter). But after playing for a while, all I found to be possible is fully populating TableLayout programatically. Still, creating TableRow by TableRow and setting layout attributes directly in java code doesn't seem elegant enough. So the questions are: Am I at the right path? Is TableLayout really best View to accomplish that? Maybe it's more appropriate to extend ListView or something else to meet such requirements? Is it possible to have TableLayout/TableRow template specified in *.xml and data bound to this template in java side?

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  • Any free networking lab?

    - by Gok Demir
    I want to study network. But I don't have an access to a sample network (routers, DNS, IP4, IP6 windows linux mixed heterogenous system). Do you know any online network to study (Free as possible). Is it possible to simulate network topologies with a single PC using virtual machine. If so could you guide me?

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  • Using an ATA-100 Hard Drive with a Thermaltake BlacX External Hard Drive Dock

    - by Joe
    Is it possible for a Thermaltake BlacX HDD Dock to connect to and recognize an ATA-100 Hard Drive? I know that the specifications for the BlacX say that it only supports SATA & SATAII, but I was hoping for one of three things: 1) for it to still work even though it isn't supported 2) for there to be some sort of workaround to make this possible 3) for there to be another part of some sort that I could purchase to make this work

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  • Getting ANT to scp only new/changed files

    - by Artem
    I would like to optimize my scp deployment which currently copies all files to only copy files that have changed since the last build. I believe it should be possible with the current setup somehow, but I don't know how to do this. I have the following: Project/src/blah/blah/ <---- files I am editing (mostly PHP in this case, some static assets) Project/build <------- I have a local build step that I use to copy the files to here I have an scp task right now that copies all of Project/build out to a remote server when I need it. Is it possible to somehow take advantage of this extra "build" directory to accomplish what I want -- meaning I only want to upload the "diff" between src/** and build/**. Is it possible to somehow retrieve this as a fileset in ANT and then scp that? I do realize that what it means is that if I somehow delete/mess around with files on the server in between, the ANT script would not notice, but for me this is okay.

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  • Bind an ip address to Postfix as outgoing ip

    - by jack
    Is that possible to bind all available public ip addresses on a server to one Postfix instance as its outgoing ip pool and let it choose a random ip or specified ip from the pool each time it sends out an email? If above is not possible, can it be configured to listen on one public ip address per instance and each time it delivers a message, it use the binded one as outgoing ip address.

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  • Auto-execute command after going to a folder with the CD command

    - by Patrick
    Is it possible to auto-execute a command in a folder if you move to it via the cd command? Of course I can define my own command (e.g. CHD.BAT) doing something like this: @echo off cd %1 if exist init.bat ( init.bat ) else ( color 0F title Command Prompt ) But I wonder if something like this would be possible using the standard CD command.

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  • xml schema and using a choice as the document root

    - by mikey
    I have a bit of a newbie xml schema question. I believe the answer is that what I need to do is not possible with schema, but I'd like to be sure. The problem is that I have a webservice that returns a response with one type of root element on success (say <Response), and on a complete failure, returns a document with a different root element (say, <Exception). So, basically, two completely different documents: <Response......</Response OR <Exception....</Exception Is it possible to describe these two different documents with one schema document? It's like I want a choice as the first element under the schema element -- but that isn't valid syntax. I've tried a couple of variants that parse as valid xsd, but don't validate the documents. Any suggestions? Or is this simply not possible? Thanks very much in advance -- m

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  • Different SVN Serverversions and Clients

    - by lueda
    Hi, we are going to migrate from CVS to SVN using subversion 1.6. But also we have another SVN-Server using subversion 1.2 (no chance to update). So we plan to use the newer TortoiseSVN 1.6.x Is it possible to use two different servers while using only the new TortoiseSVN? Another solution may be using an old TortoiseSVN compiled against subversion 1.2. Is this possible? What about using two TortoiseSVN (1.2.x and 1.6.x)?

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  • Sql Server CE - Temporary disable auto increment on a specific collum

    - by Fábio Antunes
    Hi guys. I have this little question, thats been on my head for while now. Here it goes: Is it possible to temporary disable the Auto_Increment on the collum ID. So that i can add a new row to the table and being able specify the ID value when inserting the row. And then in the end enable the Auto_Increment again, and let do its work as usual? And if its possible how can i do it. The Table structure is very simple Collum Name (atributes) ID (Primary Key, Auto Increment, int, not null) Name (nvarchar(100), not null) Notice: The table name is: People. Lets also consider that the table already has data and cannot be changed. The database server is SQL Server CE. The SQL commands will be executed in a C# program, if its of any help. I really hope its possible, it would come very handy. Thanks

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  • Pos receipt printer

    - by unknown (google)
    Is it possible to connect a receipt printer to a telephone for printing similar to how a Credit card terminal works when connected to a telephone line. Our clients donot have internet connections where we can connect the printer over Ethernet, so was thinking if it was possible to do the same via telephone line.

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  • Outlook meetings and auto accept/reply

    - by Morten
    First, I'm not sure if this question should be here or superuser, but here it comes. Im trying to set up a room to auto accept meetings and so far its good but i was wondering if it's possible to change it to "do not send respond" when it accepts and sends some reply when it's the same time as another existing meeting, so it declined. And a little extra question: is it possible to chance that auto reply it sends, since it's in English, and I would like to chance it to Danish and some text I choose myself?

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  • Traversing Scheme function as a list

    - by csl
    Isn't it possible to treat functions in Scheme as any other list? Basically, what I want do to is something like this: (define (foo) "hello") (cdr foo) ; or similar, should return the list ((foo) "hello") I've found a similar discussion about this, and I feel a bit disappointed if this is not possible with Scheme. If so, why is this impossible? Is it possible in other lisps? EDIT: Changed (cdr 'foo) to (cdr foo) -- it was misleading. I'm asking, why can't I access a function as a list?

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