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  • Fast block placement algorithm, advice needed?

    - by James Morris
    I need to emulate the window placement strategy of the Fluxbox window manager. As a rough guide, visualize randomly sized windows filling up the screen one at a time, where the rough size of each results in an average of 80 windows on screen without any window overlapping another. It is important to note that windows will close and the space that closed windows previously occupied becomes available once more for the placement of new windows. The window placement strategy has three binary options: Windows build horizontal rows or vertical columns (potentially) Windows are placed from left to right or right to left Windows are placed from top to bottom or bottom to top Why is the algorithm a problem? It needs to operate to the deadlines of a real time thread in an audio application. At this moment I am only concerned with getting a fast algorithm, don't concern yourself over the implications of real time threads and all the hurdles in programming that that brings. So far I have two choices which I have built loose prototypes for: 1) A port of the Fluxbox placement algorithm into my code. The problem with this is, the client (my program) gets kicked out of the audio server (JACK) when I try placing the worst case scenario of 256 blocks using the algorithm. This algorithm performs over 14000 full (linear) scans of the list of blocks already placed when placing the 256th window. 2) My alternative approach. Only partially implemented, this approach uses a data structure for each area of rectangular free unused space (the list of windows can be entirely separate, and is not required for testing of this algorithm). The data structure acts as a node in a doubly linked list (with sorted insertion), as well as containing the coordinates of the top-left corner, and the width and height. Furthermore, each block data structure also contains four links which connect to each immediately adjacent (touching) block on each of the four sides. IMPORTANT RULE: Each block may only touch with one block per side. The problem with this approach is, it's very complex. I have implemented the straightforward cases where 1) space is removed from one corner of a block, 2) splitting neighbouring blocks so that the IMPORTANT RULE is adhered to. The less straightforward case, where the space to be removed can only be found within a column or row of boxes, is only partially implemented - if one of the blocks to be removed is an exact fit for width (ie column) or height (ie row) then problems occur. And don't even mention the fact this only checks columns one box wide, and rows one box tall. I've implemented this algorithm in C - the language I am using for this project (I've not used C++ for a few years and am uncomfortable using it after having focused all my attention to C development, it's a hobby). The implementation is 700+ lines of code (including plenty of blank lines, brace lines, comments etc). The implementation only works for the horizontal-rows + left-right + top-bottom placement strategy. So I've either got to add some way of making this +700 lines of code work for the other 7 placement strategy options, or I'm going to have to duplicate those +700 lines of code for the other seven options. Neither of these is attractive, the first, because the existing code is complex enough, the second, because of bloat. The algorithm is not even at a stage where I can use it in the real time worst case scenario, because of missing functionality, so I still don't know if it actually performs better or worse than the first approach. What else is there? I've skimmed over and discounted: Bin Packing algorithms: their emphasis on optimal fit does not match the requirements of this algorithm. Recursive Bisection Placement algorithms: sounds promising, but these are for circuit design. Their emphasis is optimal wire length. Both of these, especially the latter, all elements to be placed/packs are known before the algorithm begins. I need an algorithm which works accumulatively with what it is given to do when it is told to do it. What are your thoughts on this? How would you approach it? What other algorithms should I look at? Or even what concepts should I research seeing as I've not studied computer science/software engineering? Please ask questions in comments if further information is needed. [edit] If it makes any difference, the units for the coordinates will not be pixels. The units are unimportant, but the grid where windows/blocks/whatever can be placed will be 127 x 127 units.

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  • Neural Network Always Produces Same/Similar Outputs for Any Input

    - by l33tnerd
    I have a problem where I am trying to create a neural network for Tic-Tac-Toe. However, for some reason, training the neural network causes it to produce nearly the same output for any given input. I did take a look at Artificial neural networks benchmark, but my network implementation is built for neurons with the same activation function for each neuron, i.e. no constant neurons. To make sure the problem wasn't just due to my choice of training set (1218 board states and moves generated by a genetic algorithm), I tried to train the network to reproduce XOR. The logistic activation function was used. Instead of using the derivative, I multiplied the error by output*(1-output) as some sources suggested that this was equivalent to using the derivative. I can put the Haskell source on HPaste, but it's a little embarrassing to look at. The network has 3 layers: the first layer has 2 inputs and 4 outputs, the second has 4 inputs and 1 output, and the third has 1 output. Increasing to 4 neurons in the second layer didn't help, and neither did increasing to 8 outputs in the first layer. I then calculated errors, network output, bias updates, and the weight updates by hand based on http://hebb.mit.edu/courses/9.641/2002/lectures/lecture04.pdf to make sure there wasn't an error in those parts of the code (there wasn't, but I will probably do it again just to make sure). Because I am using batch training, I did not multiply by x in equation (4) there. I am adding the weight change, though http://www.faqs.org/faqs/ai-faq/neural-nets/part2/section-2.html suggests to subtract it instead. The problem persisted, even in this simplified network. For example, these are the results after 500 epochs of batch training and of incremental training. Input |Target|Output (Batch) |Output(Incremental) [1.0,1.0]|[0.0] |[0.5003781562785173]|[0.5009731800870864] [1.0,0.0]|[1.0] |[0.5003740346965251]|[0.5006347214672715] [0.0,1.0]|[1.0] |[0.5003734471544522]|[0.500589332376345] [0.0,0.0]|[0.0] |[0.5003674110937019]|[0.500095157458231] Subtracting instead of adding produces the same problem, except everything is 0.99 something instead of 0.50 something. 5000 epochs produces the same result, except the batch-trained network returns exactly 0.5 for each case. (Heck, even 10,000 epochs didn't work for batch training.) Is there anything in general that could produce this behavior? Also, I looked at the intermediate errors for incremental training, and the although the inputs of the hidden/input layers varied, the error for the output neuron was always +/-0.12. For batch training, the errors were increasing, but extremely slowly and the errors were all extremely small (x10^-7). Different initial random weights and biases made no difference, either. Note that this is a school project, so hints/guides would be more helpful. Although reinventing the wheel and making my own network (in a language I don't know well!) was a horrible idea, I felt it would be more appropriate for a school project (so I know what's going on...in theory, at least. There doesn't seem to be a computer science teacher at my school). EDIT: Two layers, an input layer of 2 inputs to 8 outputs, and an output layer of 8 inputs to 1 output, produces much the same results: 0.5+/-0.2 (or so) for each training case. I'm also playing around with pyBrain, seeing if any network structure there will work. Edit 2: I am using a learning rate of 0.1. Sorry for forgetting about that. Edit 3: Pybrain's "trainUntilConvergence" doesn't get me a fully trained network, either, but 20000 epochs does, with 16 neurons in the hidden layer. 10000 epochs and 4 neurons, not so much, but close. So, in Haskell, with the input layer having 2 inputs & 2 outputs, hidden layer with 2 inputs and 8 outputs, and output layer with 8 inputs and 1 output...I get the same problem with 10000 epochs. And with 20000 epochs. Edit 4: I ran the network by hand again based on the MIT PDF above, and the values match, so the code should be correct unless I am misunderstanding those equations. Some of my source code is at http://hpaste.org/42453/neural_network__not_working; I'm working on cleaning my code somewhat and putting it in a Github (rather than a private Bitbucket) repository. All of the relevant source code is now at https://github.com/l33tnerd/hsann.

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  • C++ Operator overloading - 'recreating the Vector'

    - by Wallter
    I am currently in a collage second level programing course... We are working on operator overloading... to do this we are to rebuild the vector class... I was building the class and found that most of it is based on the [] operator. When I was trying to implement the + operator I run into a weird error that my professor has not seen before (apparently since the class switched IDE's from MinGW to VS express...) (I am using Visual Studio Express 2008 C++ edition...) Vector.h #include <string> #include <iostream> using namespace std; #ifndef _VECTOR_H #define _VECTOR_H const int DEFAULT_VECTOR_SIZE = 5; class Vector { private: int * data; int size; int comp; public: inline Vector (int Comp = 5,int Size = 0) : comp(Comp), size(Size) { if (comp > 0) { data = new int [comp]; } else { data = new int [DEFAULT_VECTOR_SIZE]; comp = DEFAULT_VECTOR_SIZE; } } int size_ () const { return size; } int comp_ () const { return comp; } bool push_back (int); bool push_front (int); void expand (); void expand (int); void clear (); const string at (int); int operator[ ](int); Vector& operator+ (Vector&); Vector& operator- (const Vector&); bool operator== (const Vector&); bool operator!= (const Vector&); ~Vector() { delete [] data; } }; ostream& operator<< (ostream&, const Vector&); #endif Vector.cpp #include <iostream> #include <string> #include "Vector.h" using namespace std; const string Vector::at(int i) { this[i]; } void Vector::expand() { expand(size); } void Vector::expand(int n ) { int * newdata = new int [comp * 2]; if (*data != NULL) { for (int i = 0; i <= (comp); i++) { newdata[i] = data[i]; } newdata -= comp; comp += n; delete [] data; *data = *newdata; } else if ( *data == NULL || comp == 0) { data = new int [DEFAULT_VECTOR_SIZE]; comp = DEFAULT_VECTOR_SIZE; size = 0; } } bool Vector::push_back(int n) { if (comp = 0) { expand(); } for (int k = 0; k != 2; k++) { if ( size != comp ){ data[size] = n; size++; return true; } else { expand(); } } return false; } void Vector::clear() { delete [] data; comp = 0; size = 0; } int Vector::operator[] (int place) { return (data[place]); } Vector& Vector::operator+ (Vector& n) { int temp_int = 0; if (size > n.size_() || size == n.size_()) { temp_int = size; } else if (size < n.size_()) { temp_int = n.size_(); } Vector newone(temp_int); int temp_2_int = 0; for ( int j = 0; j <= temp_int && j <= n.size_() && j <= size; j++) { temp_2_int = n[j] + data[j]; newone[j] = temp_2_int; } //////////////////////////////////////////////////////////// return newone; //////////////////////////////////////////////////////////// } ostream& operator<< (ostream& out, const Vector& n) { for (int i = 0; i <= n.size_(); i++) { //////////////////////////////////////////////////////////// out << n[i] << " "; //////////////////////////////////////////////////////////// } return out; } Errors: out << n[i] << " "; error C2678: binary '[' : no operator found which takes a left-hand operand of type 'const Vector' (or there is no acceptable conversion) return newone; error C2106: '=' : left operand must be l-value As stated above, I am a student going into Computer Science as my selected major I would appreciate tips, pointers, and better ways to do stuff :D

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  • JavaScript snippet that populates the table

    - by kayn
    I would like to write a JavaScript snippet that populates the table based on the selection, and not create several details panes and toggle their visibility. I tried implement this using the following code but its not working as desired,firstly,it only works with internet explorer under certain conditions and it just toggles visibility of detail panes;Below is my code; <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <HTML> <HEAD> </HEAD> <BODY onLoad="tblTB_0.style.display='';tblTB_1.style.display='none'; tblTB_2.style.display='none'; tblTB_3.style.display='none'"> <center> <table> <tr> <td> <H1> <align="left"> Candi Colledge of Computing <br/>Course Page </H1> </td> </tr> </table> </center> <hr> </br> <H2><P STYLE="color: blue">Honours Courses.</H2> <left> <p><a href="" onclick="tblTB_1.style.display=''; tblTB_2.style.display='none'; tblTB_3.style.display='none'"> Concurrent Programming</a> <br/> <a href="" onclick="tblTB_1.style.display='none';tblTB_2.style.display=''; tblTB_3.style.display='none'">Simulation of Networks</a><br/> <a href="" onclick="tblTB_1.style.display='none';tblTB_2.style.display='none'; tblTB_3.style.display=''">Advanced Computer Science Topics</a></p> <br> <table style="table-layout: fixed"; border=1> <colgroup> <col width="100px"><col width="150px"><col width="150px"> </colgroup> <tbody id="tblTB_0"> <tr> <td>Course Code</td> <td>Lecturer</td> <td>Hours/Week</td> <td>Credits</td> </tr> </tbody> <tbody id="tblTB_1"> <tr> <td>RW 714</td> <td>Dr. kate</td> <td>2 hrs</td> <td>15</td </tr> </tbody> <tbody id="tblTB_2"> <tr> <td>RW 742</td> <td>Prof. Broz</td> <td>4 hrs</td> <td>10</td> </tr> </tbody> <tbody id="tblTB_3"> <tr> <td>RW 716</td> <td>Consultant</td> <td>3 hrs</td> <td>12</td> </tr> </tbody> </table> </left> <br> </BODY> </HTML>

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  • CodePlex Daily Summary for Thursday, March 01, 2012

    CodePlex Daily Summary for Thursday, March 01, 2012Popular ReleasesMetodología General Ajustada - MGA: 01.09.08: Cambios John: Cambios en el MDI: Habilitación del menú e ícono de Imprimir. Deshabilitación de menú Ayuda y opciones de Importar y Exportar del menú Proyectos temporalmente. Integración con código de Crystal Report. Validaciones con Try-Catch al generar los reportes, personalización de los formularios en estilos y botones y validación de selección de tipo de reporte. Creación de instalador con TODOS los cambios y la creación de las carpetas asociadas a los RPT.WatchersNET CKEditor™ Provider for DotNetNuke®: CKEditor Provider 1.14.01: Whats NewAdded New Plugin "Ventrian News Articles Link Selector" to select an Article Link from the News Article Module (This Plugin is not visible by default in your Toolbar, you need to manually add the 'newsarticleslinks' to your toolbarset) http://www.watchersnet.de/Portals/0/screenshots/dnn/CKEditorNewsArticlesLinks.png File-Browser: Added Paging to the Files List. You can define the Page Size in the Options (Default Value: 20) http://www.watchersnet.de/Portals/0/screenshots/dnn/CKEdito...MyRouter (Virtual WiFi Router): MyRouter 1.0 (Beta): A friendlier User Interface. A logger file to catch exceptions so you may send it to use to improve and fix any bugs that may occur. A feedback form because we always love hearing what you guy's think of MyRouter. Check for update menu item for you to stay up to date will the latest changes. Facebook fan page so you may spread the word and share MyRouter with friends and family And Many other exciting features were sure your going to love!WPF Sound Visualization Library: WPF SVL 0.3 (Source, Binaries, Examples, Help): Version 0.3 of WPFSVL. This includes three new controls: an equalizer, a digital clock, and a time editor.Thai Flood Watch: Thai Flood Watch - Source: non commercial use only ** This project supported by Department of Computer Science KhonKaen University Thailand.ZXing.Net: ZXing.Net 0.4.0.0: sync with rev. 2196 of the java version important fix for RGBLuminanceSource generating barcode bitmaps Windows Phone demo client (only tested with emulator, because I don't have a Windows Phone) Barcode generation support for Windows Forms demo client Webcam support for Windows Forms demo clientOrchard Project: Orchard 1.4: Please read our release notes for Orchard 1.4: http://docs.orchardproject.net/Documentation/Orchard-1-4-Release-Notes.NET Assembly Information: Assembly Information 2.1.0.1: - Fixed the issue in which AnyCPU binaries were shown as 32bit - Added support to show the errors in-case if some dlls failed to load.FluentData -Micro ORM with a fluent API that makes it simple to query a database: FluentData version 1.2: New features: - QueryValues method - Added support for automapping to enumerations (both int and string are supported). Fixed 2 reported issues.NetSqlAzMan - .NET SQL Authorization Manager: 3.6.0.15: 3.6.0.15 28-Feb-2012 • Fix: The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state. Work Item 10435: http://netsqlazman.codeplex.com/workitem/10435 • Fix: Made StorageCache thread safe. Thanks to tangrl. • Fix: Members property of SqlAzManApplicationGroup is not functioning. Thanks to tangrl. Work Item 10267: http://netsqlazman.codeplex.com/workitem/10267 • Fix: Indexer are making database calls. Thanks to t...SCCM Client Actions Tool: Client Actions Tool v1.1: SCCM Client Actions Tool v1.1 is the latest version. It comes with following changes since last version: Added stop button to stop the ongoing process. Added action "Query update status". Added option "saveOnlineComputers" in config.ini to enable saving list of online computers from last session. Default value for "LatestClientVersion" set to SP2 R3 (4.00.6487.2157). Wuauserv service manual startup mode is considered healthy on Windows 7. Errors are now suppressed in checkReleases...Kinect PowerPoint Control: Kinect PowerPoint Control v1.1: Updated for Kinect SDK 1.0.SharpCompress - a fully native C# library for RAR, 7Zip, Zip, Tar, GZip, BZip2: SharpCompress 0.8: API Updates: SOLID Extract Method for Archives (7Zip and RAR). ExtractAllEntries method on Archive classes will extract archives as a streaming file. This can offer better 7Zip extraction performance if any of the entries are solid. The IsSolid method on 7Zip archives will return true if any are solid. Removed IExtractionListener was removed in favor of events. Unit tests show example. Bug fixes: PPMd passes tests plus other fixes (Thanks Pavel) Zip used to always write a Post Descri...Social Network Importer for NodeXL: SocialNetImporter(v.1.3): This new version includes: - Download new networks for Facebook fan pages. - New options for downloading more posts - Bug fixes To use the new graph data provider, do the following: Unzip the Zip file into the "PlugIns" folder that can be found in the NodeXL installation folder (i.e "C:\Program Files\Social Media Research Foundation\NodeXL Excel Template\PlugIns") Open NodeXL template and you can access the new importer from the "Import" menuASP.NET REST Services Framework: Release 1.1 - Standard version: Beginning from v1.1 the REST-services Framework is compatible with ASP.NET Routing model as well with CRUD (Create, Read, Update, and Delete) principle. These two are often important when building REST API functionality within your application. It also includes ability to apply Filters to a class to target all WebRest methods, as well as some performance enhancements. New version includes Metadata Explorer providing ability exploring the existing services that becomes essential as the number ...SQL Live Monitor: SQL Live Monitor 1.31: A quick fix to make it this version work with SQL 2012. Version 2 already has 2012 working, but am still developing the UI in version 2, so this is just an interim fix to allow user to monitor SQL 2012.Content Slider Module for DotNetNuke: 01.02.00: This release has the following updates and new features: Feature: One-Click Enabling of Pager Setting Feature: Cache Sliders for Performance Feature: Configurable Cache Setting Enhancement: Transitions can be Selected Bug: Secure Folder Images not Viewable Bug: Sliders Disappear on Postback Bug: Remote Images Cause Error Bug: Deleted Images Cause Error System Requirements DotNetNuke v06.00.00 or newer .Net Framework v3.5 SP1 or newer SQL Server 2005 or newerImage Resizer for Windows: Image Resizer 3 Preview 3: Here is yet another iteration toward what will eventually become Image Resizer 3. This release is stable. However, I'm calling it a preview since there are still many features I'd still like to add before calling it complete. Updated on February 28 to fix an issue with installing on multi-user machines. As usual, here is my progress report. Done Preview 3 Fix: 3206 3076 3077 5688 Fix: 7420 Fix: 7527 Fix: 7576 7612 Preview 2 6308 6309 Fix: 7339 Fix: 7357 Preview 1 UI...Finestra Virtual Desktops: 2.5.4500: This is a bug fix release for version 2.5. It fixes several things and adds a couple of minor features. See the 2.5 release notes for more information on the major new features in that version. Important - If Finestra crashes on startup for you, you must install the Visual C++ 2010 runtime from http://www.microsoft.com/download/en/details.aspx?id=5555. Fixes a bug with window animations not refreshing the screen on XP and with DWM off Fixes a bug with with crashing on XP due to a bug in t...Media Companion: MC 3.432b Release: General Now remembers window location. Catching a few more exceptions when an image is blank TV A couple of UI tweaks Movies Fixed the actor name displaying HTML Fixed crash when using Save files as "movie.nfo", "movie.tbn", & "fanart.jpg" New CSV template for HTML output function Added <createdate> tag for HTML output A couple of UI tweaks Known Issues Multiepisodes are not handled correctly in MC. The created nfo is valid, but they are not displayed in MC correctly & saving the...New Projectsabac: abac cn websiteAION Launcher: simple aion launcher...just edit the background image of your choosing inside the code and other things such as the links for the buttons and the ip adress and port of the serverAXTFSTool: Dynamics AX tool that connects to your project's TFS and lists the objects your colleagues have changed. Written in C#, still under development and improvements. Useful for team leaders, deployment managers, etc.cookieTopo: Topo map viewerCrmFetchKit.js: Simple Library at allows the execution of fetchxml queries via JavaScript for Dynamics CRM 2011 (using the new WCF endpoints). Like the CrmRestKit this framework uses the promise/A capacities of jQuery. The code and the idea for this framework bases on the CrmServiceToolkit (http://crmtoolkit.codeplex.com/) developed by Daniel Cai. cy univerX engine: ????????DNSAPI.NET: A common API for managing DNS servers on Windows. This project is based on the work I started back in 2002 when I needed to create a web front-end for Windows' DNS server using the .Net framework. The plan is to expand on the project and include support for the BIND server on Windows too. ego.net: ego.netfdTFS: Team Foundation Server Source Control Plugin for FlashDevelopGeoWPS: GeoWPS is an implementation of the OGC WPS. It will be developed in C#. IThink: A new project.King Garden: Boy King's .net practical projects.King Garret: Boy King's .net learning projects.LottoCheck: Follow LottoNot-Terraria: This is a like terraria game but NOT terrariaPassword Protector: Password Protector SharePoint 2010 BlobCache Manager: Manage your web application's blobcache settings directly in the central administration.SharePoint 2010 SilverLight Multiple File Uploader: SharePoint 2010 SilverLight Multiple File Uploader for Documents Libraries with MetaData.Sharepoint Tool Collection: I want to Integrate Various Utilities of Sharepoint at one place. It is for easy working of user or developer. Ex-1. A utility which takes some params & csv file and upload 100s of items on the sharepoint list easily. Ex-2 A utility to upload documents in a library. etc.SQLCLR Cmd Exec Framework Example: For users of MS SQL Server, xp_cmdshell is a utility that we usually want to have disabled. However there are still cases where calling a command line is needed. This project provides an framework/example to make command line calls. It is not meant as an xp_cmdshell replacement but as a workaround.Symmetric Designs Python 3.2: Symmetric Designs for Python 3.2 helps graphical artists to design and develop their own designs freestyle. It uses the pygame module for Python 3.2. It can also be analysed in order to get a grasp of graphics programming in Python.Terminsoft open CLR libraries: Terminsoft open CLR libraries. The first is Terminsoft.Intervals, intended for modeling the sets of intervals with elements, the comparison operation is defined for. The second is Terminsoft.Syntax, intended for text parsing and transformation and built upon regular expressions.Thai Flood Watch: Thai Flood Watch provides useful information, up-to-date and visual access to the major canal in Bangkok, Thailand using data from department of drainage and sewerage. Easily monitor river and canal flow information in Bangkok area, right from your hand.TheNerd: Sample video game source code. Using Sunburn.Unity.WebAPI: A library that allows simple Integration of Microsoft's Unity IoC container with ASP.NET's WebAPI. This project includes a bespoke DependencyResolver that creates a child container per HTTP request and disposes of all registered IDisposable instances at the end of the request.Wholemy.RemoteTouch: The project is a remote touch-sensitive keyboard with a customizable interface which allows to supplement control of another computer, regardless of the wires. For example, if you have not so fast Tablet PC - a client and a fast desktop computer - the server using the network.WindowPlace: WindowPlace makes it possible to save Window positions and sizes to a profile. Switching between profiles will effortlessly move and resize your windows. Help improve productivity - especially for multi-monitor systems. Developed in C# using WPF and a few Windows API calls in the background. WP Error Manager (Devv.Core.WPErrorManager): Library to log, handle and report errors on Windows Phone 7 apps. Fully customizable and extremely easy to implement. Works with any WP7 app. Tested with the emulator, Nokia Lumia 800 and Samsung Focus Flash.WPMatic: Windows Phone7 App to manage Homematic (eQ-3) Devices. The App is like the Homematic Central Configuration Unit (CCU) in German.www.Nabaza.com Freeware and Ebooks: www.Nabaza.com Freeware and Ebooks by William R. NabazaZap: Zap is a light weight .NET communication framework. It is designed for programs running in local area network. Zap provides code generation tool that enables user to call remote methods, add/remote event listener to remote objects, while hides the lower details.

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  • Enterprise Process Maps: A Process Picture worth a Million Words

    - by raul.goycoolea
    p { margin-bottom: 0.08in; }h1 { margin-top: 0.33in; margin-bottom: 0in; color: rgb(54, 95, 145); page-break-inside: avoid; }h1.western { font-family: "Cambria",serif; font-size: 14pt; }h1.cjk { font-family: "DejaVu Sans"; font-size: 14pt; }h1.ctl { font-size: 14pt; } Getting Started with Business Transformations A well-known proverb states that "A picture is worth a thousand words." In relation to Business Process Management (BPM), a credible analyst might have a few questions. What if the picture was taken from some particular angle, like directly overhead? What if it was taken from only an inch away or a mile away? What if the photographer did not focus the camera correctly? Does the value of the picture depend on who is looking at it? Enterprise Process Maps are analogous in this sense of relative value. Every BPM project (holistic BPM kick-off, enterprise system implementation, Service-oriented Architecture, business process transformation, corporate performance management, etc.) should be begin with a clear understanding of the business environment, from the biggest picture representations down to the lowest level required or desired for the particular project type, scope and objectives. The Enterprise Process Map serves as an entry point for the process architecture and is defined: the single highest level of process mapping for an organization. It is constructed and evaluated during the Strategy Phase of the Business Process Management Lifecycle. (see Figure 1) Fig. 1: Business Process Management Lifecycle Many organizations view such maps as visual abstractions, constructed for the single purpose of process categorization. This, in turn, results in a lesser focus on the inherent intricacies of the Enterprise Process view, which are explored in the course of this paper. With the main focus of a large scale process documentation effort usually underlying an ERP or other system implementation, it is common for the work to be driven by the desire to "get to the details," and to the type of modeling that will derive near-term tangible results. For instance, a project in American Pharmaceutical Company X is driven by the Director of IT. With 120+ systems in place, and a lack of standardized processes across the United States, he and the VP of IT have decided to embark on a long-term ERP implementation. At the forethought of both are questions, such as: How does my application architecture map to the business? What are each application's functionalities, and where do the business processes utilize them? Where can we retire legacy systems? Well-developed BPM methodologies prescribe numerous model types to capture such information and allow for thorough analysis in these areas. Process to application maps, Event Driven Process Chains, etc. provide this level of detail and facilitate the completion of such project-specific questions. These models and such analysis are appropriately carried out at a relatively low level of process detail. (see figure 2) Fig. 2: The Level Concept, Generic Process HierarchySome of the questions remaining are ones of documentation longevity, the continuation of BPM practice in the organization, process governance and ownership, process transparency and clarity in business process objectives and strategy. The Level Concept in Brief Figure 2 shows a generic, four-level process hierarchy depicting the breakdown of a "Process Area" into progressively more detailed process classifications. The number of levels and the names of these levels are flexible, and can be fit to the standards of the organization's chosen terminology or any other chosen reference model that makes logical sense for both short and long term process description. It is at Level 1 (in this case the Process Area level), that the Enterprise Process Map is created. This map and its contained objects become the foundation for a top-down approach to subsequent mapping, object relationship development, and analysis of the organization's processes and its supporting infrastructure. Additionally, this picture serves as a communication device, at an executive level, describing the design of the business in its service to a customer. It seems, then, imperative that the process development effort, and this map, start off on the right foot. Figuring out just what that right foot is, however, is critical and trend-setting in an evolving organization. Key Considerations Enterprise Process Maps are usually not as living and breathing as other process maps. Just as it would be an extremely difficult task to change the foundation of the Sears Tower or a city plan for the entire city of Chicago, the Enterprise Process view of an organization usually remains unchanged once developed (unless, of course, an organization is at a stage where it is capable of true, high-level process innovation). Regardless, the Enterprise Process map is a key first step, and one that must be taken in a precise way. What makes this groundwork solid depends on not only the materials used to construct it (process areas), but also the layout plan and knowledge base of what will be built (the entire process architecture). It seems reasonable that care and consideration are required to create this critical high level map... but what are the important factors? Does the process modeler need to worry about how many process areas there are? About who is looking at it? Should he only use the color pink because it's his boss' favorite color? Interestingly, and perhaps surprisingly, these are all valid considerations that may just require a bit of structure. Below are Three Key Factors to consider when building an Enterprise Process Map: Company Strategic Focus Process Categorization: Customer is Core End-to-end versus Functional Processes Company Strategic Focus As mentioned above, the Enterprise Process Map is created during the Strategy Phase of the Business Process Management Lifecycle. From Oracle Business Process Management methodology for business transformation, it is apparent that business processes exist for the purpose of achieving the strategic objectives of an organization. In a prescribed, top-down approach to process development, it must be ensured that each process fulfills its objectives, and in an aggregated manner, drives fulfillment of the strategic objectives of the company, whether for particular business segments or in a broader sense. This is a crucial point, as the strategic messages of the company must therefore resound in its process maps, in particular one that spans the processes of the complete business: the Enterprise Process Map. One simple example from Company X is shown below (see figure 3). Fig. 3: Company X Enterprise Process Map In reviewing Company X's Enterprise Process Map, one can immediately begin to understand the general strategic mindset of the organization. It shows that Company X is focused on its customers, defining 10 of its process areas belonging to customer-focused categories. Additionally, the organization views these end-customer-oriented process areas as part of customer-fulfilling value chains, while support process areas do not provide as much contiguous value. However, by including both support and strategic process categorizations, it becomes apparent that all processes are considered vital to the success of the customer-oriented focus processes. Below is an example from Company Y (see figure 4). Fig. 4: Company Y Enterprise Process Map Company Y, although also a customer-oriented company, sends a differently focused message with its depiction of the Enterprise Process Map. Along the top of the map is the company's product tree, overarching the process areas, which when executed deliver the products themselves. This indicates one strategic objective of excellence in product quality. Additionally, the view represents a less linear value chain, with strong overlaps of the various process areas. Marketing and quality management are seen as a key support processes, as they span the process lifecycle. Often, companies may incorporate graphics, logos and symbols representing customers and suppliers, and other objects to truly send the strategic message to the business. Other times, Enterprise Process Maps may show high level of responsibility to organizational units, or the application types that support the process areas. It is possible that hundreds of formats and focuses can be applied to an Enterprise Process Map. What is of vital importance, however, is which formats and focuses are chosen to truly represent the direction of the company, and serve as a driver for focusing the business on the strategic objectives set forth in that right. Process Categorization: Customer is Core In the previous two examples, processes were grouped using differing categories and techniques. Company X showed one support and three customer process categorizations using encompassing chevron objects; Customer Y achieved a less distinct categorization using a gradual color scheme. Either way, and in general, modeling of the process areas becomes even more valuable and easily understood within the context of business categorization, be it strategic or otherwise. But how one categorizes their processes is typically more complex than simply choosing object shapes and colors. Previously, it was stated that the ideal is a prescribed top-down approach to developing processes, to make certain linkages all the way back up to corporate strategy. But what about external influences? What forces push and pull corporate strategy? Industry maturity, product lifecycle, market profitability, competition, etc. can all drive the critical success factors of a particular business segment, or the company as a whole, in addition to previous corporate strategy. This may seem to be turning into a discussion of theory, but that is far from the case. In fact, in years of recent study and evolution of the way businesses operate, cross-industry and across the globe, one invariable has surfaced with such strength to make it undeniable in the game plan of any strategy fit for survival. That constant is the customer. Many of a company's critical success factors, in any business segment, relate to the customer: customer retention, satisfaction, loyalty, etc. Businesses serve customers, and so do a business's processes, mapped or unmapped. The most effective way to categorize processes is in a manner that visualizes convergence to what is core for a company. It is the value chain, beginning with the customer in mind, and ending with the fulfillment of that customer, that becomes the core or the centerpiece of the Enterprise Process Map. (See figure 5) Fig. 5: Company Z Enterprise Process Map Company Z has what may be viewed as several different perspectives or "cuts" baked into their Enterprise Process Map. It has divided its processes into three main categories (top, middle, and bottom) of Management Processes, the Core Value Chain and Supporting Processes. The Core category begins with Corporate Marketing (which contains the activities of beginning to engage customers) and ends with Customer Service Management. Within the value chain, this company has divided into the focus areas of their two primary business lines, Foods and Beverages. Does this mean that areas, such as Strategy, Information Management or Project Management are not as important as those in the Core category? No! In some cases, though, depending on the organization's understanding of high-level BPM concepts, use of category names, such as "Core," "Management" or "Support," can be a touchy subject. What is important to understand, is that no matter the nomenclature chosen, the Core processes are those that drive directly to customer value, Support processes are those which make the Core processes possible to execute, and Management Processes are those which steer and influence the Core. Some common terms for these three basic categorizations are Core, Customer Fulfillment, Customer Relationship Management, Governing, Controlling, Enabling, Support, etc. End-to-end versus Functional Processes Every high and low level of process: function, task, activity, process/work step (whatever an organization calls it), should add value to the flow of business in an organization. Suppose that within the process "Deliver package," there is a documented task titled "Stop for ice cream." It doesn't take a process expert to deduce the room for improvement. Though stopping for ice cream may create gain for the one person performing it, it likely benefits neither the organization nor, more importantly, the customer. In most cases, "Stop for ice cream" wouldn't make it past the first pass of To-Be process development. What would make the cut, however, would be a flow of tasks that, each having their own value add, build up to greater and greater levels of process objective. In this case, those tasks would combine to achieve a status of "package delivered." Figure 3 shows a simple example: Just as the package can only be delivered (outcome of the process) without first being retrieved, loaded, and the travel destination reached (outcomes of the process steps), some higher level of process "Play Practical Joke" (e.g., main process or process area) cannot be completed until a package is delivered. It seems that isolated or functionally separated processes, such as "Deliver Package" (shown in Figure 6), are necessary, but are always part of a bigger value chain. Each of these individual processes must be analyzed within the context of that value chain in order to ensure successful end-to-end process performance. For example, this company's "Create Joke Package" process could be operating flawlessly and efficiently, but if a joke is never developed, it cannot be created, so the end-to-end process breaks. Fig. 6: End to End Process Construction That being recognized, it is clear that processes must be viewed as end-to-end, customer-to-customer, and in the context of company strategy. But as can also be seen from the previous example, these vital end-to-end processes cannot be built without the functionally oriented building blocks. Without one, the other cannot be had, or at least not in a complete and organized fashion. As it turns out, but not discussed in depth here, the process modeling effort, BPM organizational development, and comprehensive coverage cannot be fully realized without a semi-functional, process-oriented approach. Then, an Enterprise Process Map should be concerned with both views, the building blocks, and access points to the business-critical end-to-end processes, which they construct. Without the functional building blocks, all streams of work needed for any business transformation would be lost mess of process disorganization. End-to-end views are essential for utilization in optimization in context, understanding customer impacts, base-lining all project phases and aligning objectives. Including both views on an Enterprise Process Map allows management to understand the functional orientation of the company's processes, while still providing access to end-to-end processes, which are most valuable to them. (See figures 7 and 8). Fig. 7: Simplified Enterprise Process Map with end-to-end Access Point The above examples show two unique ways to achieve a successful Enterprise Process Map. The first example is a simple map that shows a high level set of process areas and a separate section with the end-to-end processes of concern for the organization. This particular map is filtered to show just one vital end-to-end process for a project-specific focus. Fig. 8: Detailed Enterprise Process Map showing connected Functional Processes The second example shows a more complex arrangement and categorization of functional processes (the names of each process area has been removed). The end-to-end perspective is achieved at this level through the connections (interfaces at lower levels) between these functional process areas. An important point to note is that the organization of these two views of the Enterprise Process Map is dependent, in large part, on the orientation of its audience, and the complexity of the landscape at the highest level. If both are not apparent, the Enterprise Process Map is missing an opportunity to serve as a holistic, high-level view. Conclusion In the world of BPM, and specifically regarding Enterprise Process Maps, a picture can be worth as many words as the thought and effort that is put into it. Enterprise Process Maps alone cannot change an organization, but they serve more purposes than initially meet the eye, and therefore must be designed in a way that enables a BPM mindset, business process understanding and business transformation efforts. Every Enterprise Process Map will and should be different when looking across organizations. Its design will be driven by company strategy, a level of customer focus, and functional versus end-to-end orientations. This high-level description of the considerations of the Enterprise Process Maps is not a prescriptive "how to" guide. However, a company attempting to create one may not have the practical BPM experience to truly explore its options or impacts to the coming work of business process transformation. The biggest takeaway is that process modeling, at all levels, is a science and an art, and art is open to interpretation. It is critical that the modeler of the highest level of process mapping be a cognoscente of the message he is delivering and the factors at hand. Without sufficient focus on the design of the Enterprise Process Map, an entire BPM effort may suffer. For additional information please check: Oracle Business Process Management.

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  • CodePlex Daily Summary for Tuesday, April 20, 2010

    CodePlex Daily Summary for Tuesday, April 20, 2010New ProjectsASP.NET MVC Extensibility: ASP.NET MVC Extensibility.ASP.NET MVC Starter: Tekpub's ASP.NET MVC 2.0 Starter Site, as put together by Rob Conery in Episode 15 of Mastering ASP.NET MVC (http://tekpub.com/production/starter)AzureDemo: An internal Azure demo and test bed for some projects. After demo is complete this project will be closed.Basic Sprite Sheet Creator: A basic c# program to create sprite sheets. CodeDefender: Protect your .Net codes easily with this smart obfuscator!Crawlr: Tema 2 projectDocument Session Manager - Visual Studio addin: Document Session Manager is a Visual Studio 2008 addin for saving and restoring the list of opened documents (xml files, source files, winforms, et...Esferatec.Text.RegularExpressions: assembly to build regular expression patternsFIFA World Cup 2010 Mobile Sticker Checklist: FIFA World Cup 2010 Mobile Sticker Checklist is a small application for Windows Mobile developed in CF 3.5 to keep tracking of your sticker album. ...Finia.net: 追忆 游乐网·幻之大地FusspawnsAI: Fusspawns UT AI is a small test engine for a classic ut remote bot api. intending to improve ut's ai to a god like level without cheating bots(bots...G.A.E.T.: This is a Graphical Asymmetric Encryption Tool based on R.S.A. algorithm with the help of Java Language.Even though, this may be a small applicatio...ItzyBitzySpider: Webcrawler project from computer science at UCN.JingQiao.Ads: My DDD NTier Architecture example project.Managed Meizu SDK Demo: In this project we are sharing the source code to demonstrate the usage of managed SDK for Meizu cell phones, currently for M8. With the help of th...MaxxUtils.MaxxTagger: MaxxTagger: An Mp3 Tag Editor.. Add /Edit/Remove MP3 ID3 V1 and 2.3 Tags like Title, Artist, Album, Album Art, Genre. Besides tag editing, it also ...Maya Project Management: The Maya Project Management is a clone of RedMine with all its functions and plug-in support, using the following technologies: Microsoft .net Fra...MessageBoxLib: A simple, robust library for Xbox 360 and Windows development using the XNA Game Studio that makes using the Guide class's message box functionalit...MyWSAT - ASP.NET Membership Administration Tool: MyWSAT aka ASP.NET WSAT is a WebForms based website Starter Kit for the ASP.NET Membership Provider. It is a feature rich application that takes ca...OntologyCreator: this is my thesis and it is not finished yetPOS for .Net Handheld Products Service Object: POS for .Net Service Object Handheld Products Bar Code ScannerPostBinder: PostBinder is a small helper library that deserializes ASP.NET requests into C# classes. This eliminates having to write repeated hand wiring co...PostSharp for ASP.NET Web Sites: Adds support for PostSharp 2.0 on ASP.NET Web Sites.Rapid Dictionary: * Rapid Dictionary is a Translation Dictionary initialized by language learning network http://wordsteps.com. * Dictionary developed in C# and Co...ROrganizer: If you feel your movie files are kept in messy way, try out the ROrganizer which helps you rearrange them.RoRoWoBlog: 萝萝窝个人博客开源项目SPGroupDeflector - Explicitly deny groups to webs within your Site Collection: Secure webs within your MOSS or WSS Portal by explicitly denying access to specific users in SharePoint groups.SSIS ShapeFileSource: SSIS ShapeFileSource imports ESRI Shapefiles, and the associated attribute file (.dbf). The component based on the free Shapefile C Library.StoreManagement: University assignment. The task is to build an application that can perform basic CRUD operations on a property and use an arbitrary database. ...Surfium: TODO ;-)TaskCleaner: This is a Windows Forms project created to kill some running process in order to enhace the performance of Windows execution. Sometimes it is desi...The Expert Calendar: The Expert Calendar is a MOSS 2007 webpart which allows to connect to a Event Item List and display event items in a small design customizable cale...Visual Studio Find Results Window Tweak: This is a Visual Studio 2010 add-in which enables you to adjust the format of the Find Results Window. It is written in C#, .NET 4.0 and requires ...Weightlifting Sinclair coeficient calculator: Weightlifting Sinclair coeficient calculator for competitors (for Windows Mobile platform)Windows Azure Web Storage Explorer: Windows Azure Web Storage Explorer makes it easier for developers to browse and manage Blobs, Queues and Tables from Windows Azure Storage account....New Releases#SNMP - C# Based Open Source SNMP for .NET and Mono: CatPaw (5.0) Beta 1: SNMP v3 support in snmpd is complete.ASP.Net MVC Crud with JqGrid: Mvc Crud with JqGrid 0.3.0: Fairly major reworking of the GenericDataGrid (with alot of work from James). Most noticeable is the replacing of Edit and Delete with action butt...Basic Sprite Sheet Creator: Sprite Tool v1.1: Fixed the progress bar, it now correctly displays text and progress. Also download will now come with an installer and an executable so you don't h...Basic Sprite Sheet Creator: Sprite Tool Version 1.0: Program used to make basic sprite sheets. please visit http://coderplex.blogspot.com for more infoBraintree Client Library: Braintree-1.2.1: Escape all XMLCodeDefender: CodeDefender v0.1: Protect your .Net exe and dll files with this smart tool.ColinTesting: test: testColinTesting: test2: test2ColinTesting: test3: test3ColinTesting: test4: test4ColinTesting: test6: test6CycleMania Starter Kit EAP - ASP.NET 4 Problem - Design - Solution: Cyclemania 0.08.63: See Source Code tab for recent change history.Document Session Manager - Visual Studio addin: Release v0.45948: Release v0.45948DotNetNuke® Community Edition: 05.04.00: Major Highlights Fixed issue where portal settings were not saved per portal. Fixed issue with importing page templates. Fixed issue with...DotNetNuke® Postgres Data Provider: DNN PG Provider 01.00.00 Beta2: Fixes problems with deprecated datatype money in Postgres. Upgrades DotnetNuke code base to 04.09.05 It comes with a patch for the DotNetNuke insta...FIFA World Cup 2010 Mobile Sticker Checklist: FIFA World Cup 2010 Mobile Sticker Checklist v0.1b: FIFA World Cup 2010 Mobile Sticker Checklist v0.1b First beta release. Requires Microsoft Compact Framework 3.5. It was tested on an HTC Touch Viva...FIFA World Cup 2010 Mobile Sticker Checklist: FIFA World Cup 2010 Mobile Sticker Checklist v0.2b: FIFA World Cup 2010 Mobile Sticker Checklist v0.2b Second beta release. Requires Microsoft Compact Framework 3.5. It was tested on an HTC Touch Viv...Fluent Ribbon Control Suite: Fluent Ribbon Control Suite 1.2: Fluent Ribbon Control Suite 1.2(supports .NET 3.5 and .NET 4 RTM) Includes: Fluent.dll (with .pdb and .xml) Showcase Application Samples Found...G.A.E.T.: Graphical Asymmetric Encryption Tool: User Interface The GAET User Interface is a window with five buttons. Each button is explained the following sections. Each button has a functional...HTML Ruby: 6.21.7: As long as I don't find anything else that I can improve, this will be submitted to Mozilla for review tomorrow. Added back process inserted conten...IBCSharp: IBCSharp 1.03: What IBCSharp 1.03.zip unzips to: http://i43.tinypic.com/24ffbqr.png Note: The above solution has MSTest, Typemock Isolator, and Microsoft CHESS c...LogikBug's IoC Container: Second Release: This project is dependent upon Microsoft.Practices.ServiceLocation and must be referenced when referencing LogikBug.Injection. Click here to view d...Managed Meizu SDK Demo: Library and Demo: Library and DemoMaxxUtils.MaxxTagger: MaxxUtils.MaxxTagger: Version: 1.0.0 (Beta) Instructions: Unzip the files to a folder and then dbl click on the exe. Known Issues: 1. When u copy or move a folde...OrthoLab: Cellule: Compile with Autodesk Maya 2008 32bit and 2010 64bit.OWASP Code Crawler: OWASP Code Crawler 2.7: Code Crawler 2.7 DescriptionIn terms of functionality there is not much new stuff in this release. We transplanted the new engine. Code Crawler is ...PerceptiveMCAPI - A .NET wrapper for the MailChimp Api: V1.2.3 PerceptiveMCAPI .Net Wrapper [Beta 2]: PerceptiveMCAPI – v 1.2.3 Change logFunctionality through MailChimp API announce v1.2.5 on 15-Feb-2010 .NET Wrapper New wrapper directives; api_Me...POS for .Net Handheld Products Service Object: POS for .Net Handhelp Products Service Object: The Service Object contained herein is a work in progress. This Service Object's is written as VS 2008 C# Project. The Target Platform is x86. ...PostSharp for ASP.NET Web Sites: R1: First release.Rich Ajax empowered Web/Cloud Applications: 6.4 beta 2c: A revisiov to the first fully featured version of Visual webGui offering web/cloud development tool that puts all ASP.NET Ajax limits behind with e...Should: Beta - 1.0: This is the initial release of the Should assertions extensions.Shrinkr: v1.0: First public release.Site Directory for SharePoint 2010 (from Microsoft Consulting Services, UK): v1.2: Address a bug found in v1.1 relating to the Delete Site Listings job not incrementing the 'Site Missing Count' for some SharePoint sites.Software Localization Tool: SharpSLT 1.0: New functions Backup before saving Delete entries Undo deletion Added more comments in the codeSPGroupDeflector - Explicitly deny groups to webs within your Site Collection: SPGroupDeflector: Download the source code, the wsp solution package, and Setup.docSSIS ShapeFileSource: Version 0.1: Short Preview of SSIS ShapeFileSource ComponentStarter Kit Mytrip.Mvc.Entity: Mytrip.Mvc.Entity 1.0: Warning Install MySql Connector/Net 6.3 MySQL Membership MSSQL Membership XML Membership UserManager FileManager Localization Captcha ...Surfium: Linux Expo Prebuild: First public releaseTaskCleaner: Initial Working Version: In this version we have all the features listed in the project description working fine. Built under Framework 3.5.Text to HTML: 0.4.5.0: CambiosSustitución de los siguientes caracteres: Anteriores: " < > ¡ © º ¿ Á Ä É Í Ñ Ó Ö Ú Ü ß á ä é í ñ ó ö ú ü € Nuevos: & ´ ≈ ¦ • ¸ ˆ ↓ ð … ∫ ...TS3QueryLib.Net: TS3QueryLib.Net Version 0.21.16.0: This release contains a bugfix for a bug that caused connection problems when connecting using an IP for some cases. So it's strongly recommended t...Tweety - Twitter Client: Tweety - 0.96: Form activation from system tray improved. General fixes. General code refactor.Web/Cloud Applications Development Framework | Visual WebGui: 6.4 Beta 2c: A revision to the first fully featured version of Visual webGui offering unique developer/designer interface and enhanced extensibility and customi...Windows Azure - PHP contributions: PhpAzureExtensions (Azure Drives) - 0.2.0: Extension for use with Windows Azure SDK 1.1! Breaking changes! Documentation can be found at http://phpazurecontrib.codeplex.com/wikipage?title=A...WoW Character Viewer: Viewer (40545): New setup build for 40545.Xrns2XMod: Xrns2XMod 0.0.5.3: Major Source code optimization: >> Separated logical code of xm/mod conversion from renoiseSong xml. Now all necessary renoise song data code is st...XsltDb - DotNetNuke XSLT module: 01.00.99: callable tag is introduced - create javascript ajax functions more easy import/export bug is fixed mdo:ajax checkbox processing is now the same...Most Popular ProjectsRawrWBFS ManagerSilverlight ToolkitAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseWindows Presentation Foundation (WPF)ASP.NETpatterns & practices – Enterprise LibraryPHPExcelMicrosoft SQL Server Community & SamplesMost Active ProjectsRawrpatterns & practices – Enterprise LibraryIndustrial DashboardIonics Isapi Rewrite FilterFarseer Physics EngineBlogEngine.NETPHPExcelCaliburn: An Application Framework for WPF and SilverlightNB_Store - Free DotNetNuke Ecommerce Catalog ModuleTweetSharp

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  • eBooks on iPad vs. Kindle: More Debate than Smackdown

    - by andrewbrust
    When the iPad was presented at its San Francisco launch event on January 28th, Steve Jobs spent a significant amount of time explaining how well the device would serve as an eBook reader. He showed the iBooks reader application and iBookstore and laid down the gauntlet before Amazon and its beloved Kindle device. Almost immediately afterwards, criticism came rushing forth that the iPad could never beat the Kindle for book reading. The curious part of that criticism is that virtually no one offering it had actually used the iPad yet. A few weeks later, on April 3rd, the iPad was released for sale in the United States. I bought one on that day and in the few additional weeks that have elapsed, I’ve given quite a workout to most of its capabilities, including its eBook features. I’ve also spent some time with the Kindle, albeit a first-generation model, to see how it actually compares to the iPad. I had some expectations going in, but I came away with conclusions about each device that were more scenario-based than absolute. I present my findings to you here.   Vital Statistics Let’s start with an inventory of each device’s underlying technology. The iPad has a color, backlit LCD screen and an on-screen keyboard. It has a battery which, on a full charge, lasts anywhere from 6-10 hours. The Kindle offers a monochrome, reflective E Ink display, a physical keyboard and a battery that on my first gen loaner unit can go up to a week between charges (Amazon claims the battery on the Kindle 2 can last up to 2 weeks on a single charge). The Kindle connects to Amazon’s Kindle Store using a 3G modem (the technology and network vary depending on the model) that incurs no airtime service charges whatsoever. The iPad units that are on-sale today work over WiFi only. 3G-equipped models will be on sale shortly and will command a $130 premium over their WiFi-only counterparts. 3G service on the iPad, in the U.S. from AT&T, will be fee-based, with a 250MB plan at $14.99 per month and an unlimited plan at $29.99. No contract is required for 3G service. All these tech specs aside, I think a more useful observation is that the iPad is a multi-purpose Internet-connected entertainment device, while the Kindle is a dedicated reading device. The question is whether those differences in design and intended use create a clear-cut winner for reading electronic publications. Let’s take a look at each device, in isolation, now.   Kindle To me, what’s most innovative about the Kindle is its E Ink display. E Ink really looks like ink on a sheet of paper. It requires no backlight, it’s fully visible in direct sunlight and it causes almost none of the eyestrain that LCD-based computer display technology (like that used on the iPad) does. It’s really versatile in an all-around way. Forgive me if this sounds precious, but reading on it is really a joy. In fact, it’s a genuinely relaxing experience. Through the Kindle Store, Amazon allows users to download books (including audio books), magazines, newspapers and blog feeds. Books and magazines can be purchased either on a single-issue basis or as an annual subscription. Books, of course, are purchased singly. Oddly, blogs are not free, but instead carry a monthly subscription fee, typically $1.99. To me this is ludicrous, but I suppose the free 3G service is partially to blame. Books and magazine issues download quickly. Magazine and blog subscriptions cause new issues or posts to be pushed to your device on an automated basis. Available blogs include 9000-odd feeds that Amazon offers on the Kindle Store; unless I missed something, arbitrary RSS feeds are not supported (though there are third party workarounds to this limitation). The shopping experience is integrated well, has an huge selection, and offers certain graphical perks. For example, magazine and newspaper logos are displayed in menus, and book cover thumbnails appear as well. A simple search mechanism is provided and text entry through the physical keyboard is relatively painless. It’s very easy and straightforward to enter the store, find something you like and start reading it quickly. If you know what you’re looking for, it’s even faster. Given Kindle’s high portability, very reliable battery, instant-on capability and highly integrated content acquisition, it makes reading on whim, and in random spurts of downtime, very attractive. The Kindle’s home screen lists all of your publications, and easily lets you select one, then start reading it. Once opened, publications display in crisp, attractive text that is adjustable in size. “Turning” pages is achieved through buttons dedicated to the task. Notes can be recorded, bookmarks can be saved and pages can be saved as clippings. I am not an avid book reader, and yet I found the Kindle made it really fun, convenient and soothing to read. There’s something about the easy access to the material and the simplicity of the display that makes the Kindle seduce you into chilling out and reading page after page. On the other hand, the Kindle has an awkward navigation interface. While menus are displayed clearly on the screen, the method of selecting menu items is tricky: alongside the right-hand edge of the main display is a thin column that acts as a second display. It has a white background, and a scrollable silver cursor that is moved up or down through the use of the device’s scrollwheel. Picking a menu item on the main display involves scrolling the silver cursor to a position parallel to that menu item and pushing the scrollwheel in. This navigation technique creates a disconnect, literally. You don’t really click on a selection so much as you gesture toward it. I got used to this technique quickly, but I didn’t love it. It definitely created a kind of anxiety in me, making me feel the need to speed through menus and get to my destination document quickly. Once there, I could calm down and relax. Books are great on the Kindle. Magazines and newspapers much less so. I found the rendering of photographs, and even illustrations, to be unacceptably crude. For this reason, I expect that reading textbooks on the Kindle may leave students wanting. I found that the original flow and layout of any publication was sacrificed on the Kindle. In effect, browsing a magazine or newspaper was almost impossible. Reading the text of individual articles was enjoyable, but having to read this way made the whole experience much more “a la carte” than cohesive and thematic between articles. I imagine that for academic journals this is ideal, but for consumer publications it imposes a stripped-down, low-fidelity experience that evokes a sense of deprivation. In general, the Kindle is great for reading text. For just about anything else, especially activity that involves exploratory browsing, meandering and short-attention-span reading, it presents a real barrier to entry and adoption. Avid book readers will enjoy the Kindle (if they’re not already). It’s a great device for losing oneself in a book over long sittings. Multitaskers who are more interested in periodicals, be they online or off, will like it much less, as they will find compromise, and even sacrifice, to be palpable.   iPad The iPad is a very different device from the Kindle. While the Kindle is oriented to pages of text, the iPad orbits around applications and their interfaces. Be it the pinch and zoom experience in the browser, the rich media features that augment content on news and weather sites, or the ability to interact with social networking services like Twitter, the iPad is versatile. While it shares a slate-like form factor with the Kindle, it’s effectively an elegant personal computer. One of its many features is the iBook application and integration of the iBookstore. But it’s a multi-purpose device. That turns out to be good and bad, depending on what you’re reading. The iBookstore is great for browsing. It’s color, rich animation-laden user interface make it possible to shop for books, rather than merely search and acquire them. Unfortunately, its selection is rather sparse at the moment. If you’re looking for a New York Times bestseller, or other popular titles, you should be OK. If you want to read something more specialized, it’s much harder. Unlike the awkward navigation interface of the Kindle, the iPad offers a nearly flawless touch-screen interface that seduces the user into tinkering and kibitzing every bit as much as the Kindle lulls you into a deep, concentrated read. It’s a dynamic and interactive device, whereas the Kindle is static and passive. The iBook reader is slick and fun. Use the iPad in landscape mode and you can read the book in 2-up (left/right 2-page) display; use it in portrait mode and you can read one page at a time. Rather than clicking a hardware button to turn pages, you simply drag and wipe from right-to-left to flip the single or right-hand page. The page actually travels through an animated path as it would in a physical book. The intuitiveness of the interface is uncanny. The reader also accommodates saving of bookmarks, searching of the text, and the ability to highlight a word and look it up in a dictionary. Pages display brightly and clearly. They’re easy to read. But the backlight and the glare made me less comfortable than I was with the Kindle. The knowledge that completely different applications (including the Web and email and Twitter) were just a few taps away made me antsy and very tempted to task-switch. The knowledge that battery life is an issue created subtle discomfort. If the Kindle makes you feel like you’re in a library reading room, then the iPad makes you feel, at best, like you’re under fluorescent lights at a Barnes and Noble or Borders store. If you’re lucky, you’d be on a couch or at a reading table in the store, but you might also be standing up, in the aisles. Clearly, I didn’t find this conducive to focused and sustained reading. But that may have more to do with my own tendency to read periodicals far more than books, and my neurotic . And, truth be known, the book reading experience, when not explicitly compared to Kindle’s, was still pleasant. It is also important to point out that Kindle Store-sourced books can be read on the iPad through a Kindle reader application, from Amazon, specific to the device. This offered a less rich experience than the iBooks reader, but it was completely adequate. Despite the Kindle brand of the reader, however, it offered little in terms of simulating the reading experience on its namesake device. When it comes to periodicals, the iPad wins hands down. Magazines, even if merely scanned images of their print editions, read on the iPad in a way that felt similar to reading hard copy. The full color display, touch navigation and even the ability to render advertisements in their full glory makes the iPad a great way to read through any piece of work that is measured in pages, rather than chapters. There are many ways to get magazines and newspapers onto the iPad, including the Zinio reader, and publication-specific applications like the Wall Street Journal’s and Popular Science’s. The New York Times’ free Editors’ Choice application offers a Times Reader-like interface to a subset of the Gray Lady’s daily content. The completely Web-based but iPad-optimized Times Skimmer site (at www.nytimes.com/timesskimmer) works well too. Even conventional Web sites themselves can be read much like magazines, given the iPad’s ability to zoom in on the text and crop out advertisements on the margins. While the Kindle does have an experimental Web browser, it reminded me a lot of early mobile phone browsers, only in a larger size. For text-heavy sites with simple layout, it works fine. For just about anything else, it becomes more trouble than it’s worth. And given the way magazine articles make me think of things I want to look up online, I think that’s a real liability for the Kindle.   Summing Up What I came to realize is that the Kindle isn’t so much a computer or even an Internet device as it is a printer. While it doesn’t use physical paper, it still renders its content a page at a time, just like a laser printer does, and its output appears strikingly similar. You can read the rendered text, but you can’t interact with it in any way. That’s why the navigation requires a separate cursor display area. And because of the page-oriented rendering behavior, turning pages causes a flash on the display and requires a sometimes long pause before the next page is rendered. The good side of this is that once the page is generated, no battery power is required to display it. That makes for great battery life, optimal viewing under most lighting conditions (as long as there is some light) and low-eyestrain text-centric display of content. The Kindle is highly portable, has an excellent selection in its store and is refreshingly distraction-free. All of this is ideal for reading books. And iPad doesn’t offer any of it. What iPad does offer is versatility, variety, richness and luxury. It’s flush with accoutrements even if it’s low on focused, sustained text display. That makes it inferior to the Kindle for book reading. But that also makes it better than the Kindle for almost everything else. As such, and given that its book reading experience is still decent (even if not superior), I think the iPad will give Kindle a run for its money. True book lovers, and people on a budget, will want the Kindle. People with a robust amount of discretionary income may want both devices. Everyone else who is interested in a slate form factor e-reading device, especially if they also wish to have leisure-friendly Internet access, will likely choose the iPad exclusively. One thing is for sure: iPad has reduced Kindle’s market, and may have shifted its mass market potential to a mere niche play. If Amazon is smart, it will improve its iPad-based Kindle reader app significantly. It can then leverage the iPad channel as a significant market for the Kindle Store. After all, selling the eBooks themselves is what Amazon should care most about.

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  • LLBLGen Pro feature highlights: automatic element name construction

    - by FransBouma
    (This post is part of a series of posts about features of the LLBLGen Pro system) One of the things one might take for granted but which has a huge impact on the time spent in an entity modeling environment is the way the system creates names for elements out of the information provided, in short: automatic element name construction. Element names are created in both directions of modeling: database first and model first and the more names the system can create for you without you having to rename them, the better. LLBLGen Pro has a rich, fine grained system for creating element names out of the meta-data available, which I'll describe more in detail below. First the model element related element naming features are highlighted, in the section Automatic model element naming features and after that I'll go more into detail about the relational model element naming features LLBLGen Pro has to offer in the section Automatic relational model element naming features. Automatic model element naming features When working database first, the element names in the model, e.g. entity names, entity field names and so on, are in general determined from the relational model element (e.g. table, table field) they're mapped on, as the model elements are reverse engineered from these relational model elements. It doesn't take rocket science to automatically name an entity Customer if the entity was created after reverse engineering a table named Customer. It gets a little trickier when the entity which was created by reverse engineering a table called TBL_ORDER_LINES has to be named 'OrderLine' automatically. Automatic model element naming also takes into effect with model first development, where some settings are used to provide you with a default name, e.g. in the case of navigator name creation when you create a new relationship. The features below are available to you in the Project Settings. Open Project Settings on a loaded project and navigate to Conventions -> Element Name Construction. Strippers! The above example 'TBL_ORDER_LINES' shows that some parts of the table name might not be needed for name creation, in this case the 'TBL_' prefix. Some 'brilliant' DBAs even add suffixes to table names, fragments you might not want to appear in the entity names. LLBLGen Pro offers you to define both prefix and suffix fragments to strip off of table, view, stored procedure, parameter, table field and view field names. In the example above, the fragment 'TBL_' is a good candidate for such a strip pattern. You can specify more than one pattern for e.g. the table prefix strip pattern, so even a really messy schema can still be used to produce clean names. Underscores Be Gone Another thing you might get rid of are underscores. After all, most naming schemes for entities and their classes use PasCal casing rules and don't allow for underscores to appear. LLBLGen Pro can automatically strip out underscores for you. It's an optional feature, so if you like the underscores, you're not forced to see them go: LLBLGen Pro will leave them alone when ordered to to so. PasCal everywhere... or not, your call LLBLGen Pro can automatically PasCal case names on word breaks. It determines word breaks in a couple of ways: a space marks a word break, an underscore marks a word break and a case difference marks a word break. It will remove spaces in all cases, and based on the underscore removal setting, keep or remove the underscores, and upper-case the first character of a word break fragment, and lower case the rest. Say, we keep the defaults, which is remove underscores and PasCal case always and strip the TBL_ fragment, we get with our example TBL_ORDER_LINES, after stripping TBL_ from the table name two word fragments: ORDER and LINES. The underscores are removed, the first character of each fragment is upper-cased, the rest lower-cased, so this results in OrderLines. Almost there! Pluralization and Singularization In general entity names are singular, like Customer or OrderLine so LLBLGen Pro offers a way to singularize the names. This will convert OrderLines, the result we got after the PasCal casing functionality, into OrderLine, exactly what we're after. Show me the patterns! There are other situations in which you want more flexibility. Say, you have an entity Customer and an entity Order and there's a foreign key constraint defined from the target of Order and the target of Customer. This foreign key constraint results in a 1:n relationship between the entities Customer and Order. A relationship has navigators mapped onto the relationship in both entities the relationship is between. For this particular relationship we'd like to have Customer as navigator in Order and Orders as navigator in Customer, so the relationship becomes Customer.Orders 1:n Order.Customer. To control the naming of these navigators for the various relationship types, LLBLGen Pro defines a set of patterns which allow you, using macros, to define how the auto-created navigator names will look like. For example, if you rather have Customer.OrderCollection, you can do so, by changing the pattern from {$EndEntityName$P} to {$EndEntityName}Collection. The $P directive makes sure the name is pluralized, which is not what you want if you're going for <EntityName>Collection, hence it's removed. When working model first, it's a given you'll create foreign key fields along the way when you define relationships. For example, you've defined two entities: Customer and Order, and they have their fields setup properly. Now you want to define a relationship between them. This will automatically create a foreign key field in the Order entity, which reflects the value of the PK field in Customer. (No worries if you hate the foreign key fields in your classes, on NHibernate and EF these can be hidden in the generated code if you want to). A specific pattern is available for you to direct LLBLGen Pro how to name this foreign key field. For example, if all your entities have Id as PK field, you might want to have a different name than Id as foreign key field. In our Customer - Order example, you might want to have CustomerId instead as foreign key name in Order. The pattern for foreign key fields gives you that freedom. Abbreviations... make sense of OrdNr and friends I already described word breaks in the PasCal casing paragraph, how they're used for the PasCal casing in the constructed name. Word breaks are used for another neat feature LLBLGen Pro has to offer: abbreviation support. Burt, your friendly DBA in the dungeons below the office has a hate-hate relationship with his keyboard: he can't stand it: typing is something he avoids like the plague. This has resulted in tables and fields which have names which are very short, but also very unreadable. Example: our TBL_ORDER_LINES example has a lovely field called ORD_NR. What you would like to see in your fancy new OrderLine entity mapped onto this table is a field called OrderNumber, not a field called OrdNr. What you also like is to not have to rename that field manually. There are better things to do with your time, after all. LLBLGen Pro has you covered. All it takes is to define some abbreviation - full word pairs and during reverse engineering model elements from tables/views, LLBLGen Pro will take care of the rest. For the ORD_NR field, you need two values: ORD as abbreviation and Order as full word, and NR as abbreviation and Number as full word. LLBLGen Pro will now convert every word fragment found with the word breaks which matches an abbreviation to the given full word. They're case sensitive and can be found in the Project Settings: Navigate to Conventions -> Element Name Construction -> Abbreviations. Automatic relational model element naming features Not everyone works database first: it may very well be the case you start from scratch, or have to add additional tables to an existing database. For these situations, it's key you have the flexibility that you can control the created table names and table fields without any work: let the designer create these names based on the entity model you defined and a set of rules. LLBLGen Pro offers several features in this area, which are described in more detail below. These features are found in Project Settings: navigate to Conventions -> Model First Development. Underscores, welcome back! Not every database is case insensitive, and not every organization requires PasCal cased table/field names, some demand all lower or all uppercase names with underscores at word breaks. Say you create an entity model with an entity called OrderLine. You work with Oracle and your organization requires underscores at word breaks: a table created from OrderLine should be called ORDER_LINE. LLBLGen Pro allows you to do that: with a simple checkbox you can order LLBLGen Pro to insert an underscore at each word break for the type of database you're working with: case sensitive or case insensitive. Checking the checkbox Insert underscore at word break case insensitive dbs will let LLBLGen Pro create a table from the entity called Order_Line. Half-way there, as there are still lower case characters there and you need all caps. No worries, see below Casing directives so everyone can sleep well at night For case sensitive databases and case insensitive databases there is one setting for each of them which controls the casing of the name created from a model element (e.g. a table created from an entity definition using the auto-mapping feature). The settings can have the following values: AsProjectElement, AllUpperCase or AllLowerCase. AsProjectElement is the default, and it keeps the casing as-is. In our example, we need to get all upper case characters, so we select AllUpperCase for the setting for case sensitive databases. This will produce the name ORDER_LINE. Sequence naming after a pattern Some databases support sequences, and using model-first development it's key to have sequences, when needed, to be created automatically and if possible using a name which shows where they're used. Say you have an entity Order and you want to have the PK values be created by the database using a sequence. The database you're using supports sequences (e.g. Oracle) and as you want all numeric PK fields to be sequenced, you have enabled this by the setting Auto assign sequences to integer pks. When you're using LLBLGen Pro's auto-map feature, to create new tables and constraints from the model, it will create a new table, ORDER, based on your settings I previously discussed above, with a PK field ID and it also creates a sequence, SEQ_ORDER, which is auto-assigns to the ID field mapping. The name of the sequence is created by using a pattern, defined in the Model First Development setting Sequence pattern, which uses plain text and macros like with the other patterns previously discussed. Grouping and schemas When you start from scratch, and you're working model first, the tables created by LLBLGen Pro will be in a catalog and / or schema created by LLBLGen Pro as well. If you use LLBLGen Pro's grouping feature, which allows you to group entities and other model elements into groups in the project (described in a future blog post), you might want to have that group name reflected in the schema name the targets of the model elements are in. Say you have a model with a group CRM and a group HRM, both with entities unique for these groups, e.g. Employee in HRM, Customer in CRM. When auto-mapping this model to create tables, you might want to have the table created for Employee in the HRM schema but the table created for Customer in the CRM schema. LLBLGen Pro will do just that when you check the setting Set schema name after group name to true (default). This gives you total control over where what is placed in the database from your model. But I want plural table names... and TBL_ prefixes! For now we follow best practices which suggest singular table names and no prefixes/suffixes for names. Of course that won't keep everyone happy, so we're looking into making it possible to have that in a future version. Conclusion LLBLGen Pro offers a variety of options to let the modeling system do as much work for you as possible. Hopefully you enjoyed this little highlight post and that it has given you new insights in the smaller features available to you in LLBLGen Pro, ones you might not have thought off in the first place. Enjoy!

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  • C#/.NET Little Wonders: ConcurrentBag and BlockingCollection

    - by James Michael Hare
    In the first week of concurrent collections, began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>.  The last post discussed the ConcurrentDictionary<T> .  Finally this week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see C#/.NET Little Wonders: A Redux. Recap As you'll recall from the previous posts, the original collections were object-based containers that accomplished synchronization through a Synchronized member.  With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization.  With .NET 4.0, a new breed of collections was born in the System.Collections.Concurrent namespace.  Of these, the final concurrent collection we will examine is the ConcurrentBag and a very useful wrapper class called the BlockingCollection. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this informative whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentBag<T> – Thread-safe unordered collection. Unlike the other concurrent collections, the ConcurrentBag<T> has no non-concurrent counterpart in the .NET collections libraries.  Items can be added and removed from a bag just like any other collection, but unlike the other collections, the items are not maintained in any order.  This makes the bag handy for those cases when all you care about is that the data be consumed eventually, without regard for order of consumption or even fairness – that is, it’s possible new items could be consumed before older items given the right circumstances for a period of time. So why would you ever want a container that can be unfair?  Well, to look at it another way, you can use a ConcurrentQueue and get the fairness, but it comes at a cost in that the ordering rules and synchronization required to maintain that ordering can affect scalability a bit.  Thus sometimes the bag is great when you want the fastest way to get the next item to process, and don’t care what item it is or how long its been waiting. The way that the ConcurrentBag works is to take advantage of the new ThreadLocal<T> type (new in System.Threading for .NET 4.0) so that each thread using the bag has a list local to just that thread.  This means that adding or removing to a thread-local list requires very low synchronization.  The problem comes in where a thread goes to consume an item but it’s local list is empty.  In this case the bag performs “work-stealing” where it will rob an item from another thread that has items in its list.  This requires a higher level of synchronization which adds a bit of overhead to the take operation. So, as you can imagine, this makes the ConcurrentBag good for situations where each thread both produces and consumes items from the bag, but it would be less-than-idea in situations where some threads are dedicated producers and the other threads are dedicated consumers because the work-stealing synchronization would outweigh the thread-local optimization for a thread taking its own items. Like the other concurrent collections, there are some curiosities to keep in mind: IsEmpty(), Count, ToArray(), and GetEnumerator() lock collection Each of these needs to take a snapshot of whole bag to determine if empty, thus they tend to be more expensive and cause Add() and Take() operations to block. ToArray() and GetEnumerator() are static snapshots Because it is based on a snapshot, will not show subsequent updates after snapshot. Add() is lightweight Since adding to the thread-local list, there is very little overhead on Add. TryTake() is lightweight if items in thread-local list As long as items are in the thread-local list, TryTake() is very lightweight, much more so than ConcurrentStack() and ConcurrentQueue(), however if the local thread list is empty, it must steal work from another thread, which is more expensive. Remember, a bag is not ideal for all situations, it is mainly ideal for situations where a process consumes an item and either decomposes it into more items to be processed, or handles the item partially and places it back to be processed again until some point when it will complete.  The main point is that the bag works best when each thread both takes and adds items. For example, we could create a totally contrived example where perhaps we want to see the largest power of a number before it crosses a certain threshold.  Yes, obviously we could easily do this with a log function, but bare with me while I use this contrived example for simplicity. So let’s say we have a work function that will take a Tuple out of a bag, this Tuple will contain two ints.  The first int is the original number, and the second int is the last multiple of that number.  So we could load our bag with the initial values (let’s say we want to know the last multiple of each of 2, 3, 5, and 7 under 100. 1: var bag = new ConcurrentBag<Tuple<int, int>> 2: { 3: Tuple.Create(2, 1), 4: Tuple.Create(3, 1), 5: Tuple.Create(5, 1), 6: Tuple.Create(7, 1) 7: }; Then we can create a method that given the bag, will take out an item, apply the multiplier again, 1: public static void FindHighestPowerUnder(ConcurrentBag<Tuple<int,int>> bag, int threshold) 2: { 3: Tuple<int,int> pair; 4:  5: // while there are items to take, this will prefer local first, then steal if no local 6: while (bag.TryTake(out pair)) 7: { 8: // look at next power 9: var result = Math.Pow(pair.Item1, pair.Item2 + 1); 10:  11: if (result < threshold) 12: { 13: // if smaller than threshold bump power by 1 14: bag.Add(Tuple.Create(pair.Item1, pair.Item2 + 1)); 15: } 16: else 17: { 18: // otherwise, we're done 19: Console.WriteLine("Highest power of {0} under {3} is {0}^{1} = {2}.", 20: pair.Item1, pair.Item2, Math.Pow(pair.Item1, pair.Item2), threshold); 21: } 22: } 23: } Now that we have this, we can load up this method as an Action into our Tasks and run it: 1: // create array of tasks, start all, wait for all 2: var tasks = new[] 3: { 4: new Task(() => FindHighestPowerUnder(bag, 100)), 5: new Task(() => FindHighestPowerUnder(bag, 100)), 6: }; 7:  8: Array.ForEach(tasks, t => t.Start()); 9:  10: Task.WaitAll(tasks); Totally contrived, I know, but keep in mind the main point!  When you have a thread or task that operates on an item, and then puts it back for further consumption – or decomposes an item into further sub-items to be processed – you should consider a ConcurrentBag as the thread-local lists will allow for quick processing.  However, if you need ordering or if your processes are dedicated producers or consumers, this collection is not ideal.  As with anything, you should performance test as your mileage will vary depending on your situation! BlockingCollection<T> – A producers & consumers pattern collection The BlockingCollection<T> can be treated like a collection in its own right, but in reality it adds a producers and consumers paradigm to any collection that implements the interface IProducerConsumerCollection<T>.  If you don’t specify one at the time of construction, it will use a ConcurrentQueue<T> as its underlying store. If you don’t want to use the ConcurrentQueue, the ConcurrentStack and ConcurrentBag also implement the interface (though ConcurrentDictionary does not).  In addition, you are of course free to create your own implementation of the interface. So, for those who don’t remember the producers and consumers classical computer-science problem, the gist of it is that you have one (or more) processes that are creating items (producers) and one (or more) processes that are consuming these items (consumers).  Now, the crux of the problem is that there is a bin (queue) where the produced items are placed, and typically that bin has a limited size.  Thus if a producer creates an item, but there is no space to store it, it must wait until an item is consumed.  Also if a consumer goes to consume an item and none exists, it must wait until an item is produced. The BlockingCollection makes it trivial to implement any standard producers/consumers process set by providing that “bin” where the items can be produced into and consumed from with the appropriate blocking operations.  In addition, you can specify whether the bin should have a limited size or can be (theoretically) unbounded, and you can specify timeouts on the blocking operations. As far as your choice of “bin”, for the most part the ConcurrentQueue is the right choice because it is fairly light and maximizes fairness by ordering items so that they are consumed in the same order they are produced.  You can use the concurrent bag or stack, of course, but your ordering would be random-ish in the case of the former and LIFO in the case of the latter. So let’s look at some of the methods of note in BlockingCollection: BoundedCapacity returns capacity of the “bin” If the bin is unbounded, the capacity is int.MaxValue. Count returns an internally-kept count of items This makes it O(1), but if you modify underlying collection directly (not recommended) it is unreliable. CompleteAdding() is used to cut off further adds. This sets IsAddingCompleted and begins to wind down consumers once empty. IsAddingCompleted is true when producers are “done”. Once you are done producing, should complete the add process to alert consumers. IsCompleted is true when producers are “done” and “bin” is empty. Once you mark the producers done, and all items removed, this will be true. Add() is a blocking add to collection. If bin is full, will wait till space frees up Take() is a blocking remove from collection. If bin is empty, will wait until item is produced or adding is completed. GetConsumingEnumerable() is used to iterate and consume items. Unlike the standard enumerator, this one consumes the items instead of iteration. TryAdd() attempts add but does not block completely If adding would block, returns false instead, can specify TimeSpan to wait before stopping. TryTake() attempts to take but does not block completely Like TryAdd(), if taking would block, returns false instead, can specify TimeSpan to wait. Note the use of CompleteAdding() to signal the BlockingCollection that nothing else should be added.  This means that any attempts to TryAdd() or Add() after marked completed will throw an InvalidOperationException.  In addition, once adding is complete you can still continue to TryTake() and Take() until the bin is empty, and then Take() will throw the InvalidOperationException and TryTake() will return false. So let’s create a simple program to try this out.  Let’s say that you have one process that will be producing items, but a slower consumer process that handles them.  This gives us a chance to peek inside what happens when the bin is bounded (by default, the bin is NOT bounded). 1: var bin = new BlockingCollection<int>(5); Now, we create a method to produce items: 1: public static void ProduceItems(BlockingCollection<int> bin, int numToProduce) 2: { 3: for (int i = 0; i < numToProduce; i++) 4: { 5: // try for 10 ms to add an item 6: while (!bin.TryAdd(i, TimeSpan.FromMilliseconds(10))) 7: { 8: Console.WriteLine("Bin is full, retrying..."); 9: } 10: } 11:  12: // once done producing, call CompleteAdding() 13: Console.WriteLine("Adding is completed."); 14: bin.CompleteAdding(); 15: } And one to consume them: 1: public static void ConsumeItems(BlockingCollection<int> bin) 2: { 3: // This will only be true if CompleteAdding() was called AND the bin is empty. 4: while (!bin.IsCompleted) 5: { 6: int item; 7:  8: if (!bin.TryTake(out item, TimeSpan.FromMilliseconds(10))) 9: { 10: Console.WriteLine("Bin is empty, retrying..."); 11: } 12: else 13: { 14: Console.WriteLine("Consuming item {0}.", item); 15: Thread.Sleep(TimeSpan.FromMilliseconds(20)); 16: } 17: } 18: } Then we can fire them off: 1: // create one producer and two consumers 2: var tasks = new[] 3: { 4: new Task(() => ProduceItems(bin, 20)), 5: new Task(() => ConsumeItems(bin)), 6: new Task(() => ConsumeItems(bin)), 7: }; 8:  9: Array.ForEach(tasks, t => t.Start()); 10:  11: Task.WaitAll(tasks); Notice that the producer is faster than the consumer, thus it should be hitting a full bin often and displaying the message after it times out on TryAdd(). 1: Consuming item 0. 2: Consuming item 1. 3: Bin is full, retrying... 4: Bin is full, retrying... 5: Consuming item 3. 6: Consuming item 2. 7: Bin is full, retrying... 8: Consuming item 4. 9: Consuming item 5. 10: Bin is full, retrying... 11: Consuming item 6. 12: Consuming item 7. 13: Bin is full, retrying... 14: Consuming item 8. 15: Consuming item 9. 16: Bin is full, retrying... 17: Consuming item 10. 18: Consuming item 11. 19: Bin is full, retrying... 20: Consuming item 12. 21: Consuming item 13. 22: Bin is full, retrying... 23: Bin is full, retrying... 24: Consuming item 14. 25: Adding is completed. 26: Consuming item 15. 27: Consuming item 16. 28: Consuming item 17. 29: Consuming item 19. 30: Consuming item 18. Also notice that once CompleteAdding() is called and the bin is empty, the IsCompleted property returns true, and the consumers will exit. Summary The ConcurrentBag is an interesting collection that can be used to optimize concurrency scenarios where tasks or threads both produce and consume items.  In this way, it will choose to consume its own work if available, and then steal if not.  However, in situations where you want fair consumption or ordering, or in situations where the producers and consumers are distinct processes, the bag is not optimal. The BlockingCollection is a great wrapper around all of the concurrent queue, stack, and bag that allows you to add producer and consumer semantics easily including waiting when the bin is full or empty. That’s the end of my dive into the concurrent collections.  I’d also strongly recommend, once again, you read this excellent Microsoft white paper that goes into much greater detail on the efficiencies you can gain using these collections judiciously (here). Tweet Technorati Tags: C#,.NET,Concurrent Collections,Little Wonders

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  • CodePlex Daily Summary for Tuesday, June 07, 2011

    CodePlex Daily Summary for Tuesday, June 07, 2011Popular ReleasesSCCM Client Actions Tool: SCCM Client Actions Tool v0.5: SCCM Client Actions Tool v0.5 is currently the most stable version and includes all of the functionality requested so far. It comes as a ZIP file that contains three files: ClientActionsTool.hta – The tool itself. Cmdkey.exe – command line tool for managing cached credentials. This is needed for alternate credentials feature when running the HTA on Windows XP. Cmdkey.exe is natively available starting from Windows Vista. Config.ini – A configuration file for default settings. This file is...AcDown????? - Anime&Comic Downloader: AcDown????? v3.0 Beta5: ??AcDown?????????????,??????????????,????、????。?????Acfun????? ????32??64? Windows XP/Vista/7 ????????????? ??:????????Windows XP???,?????????.NET Framework 2.0???(x86)?.NET Framework 2.0???(x64),?????"?????????"??? ??v3.0 Beta5 ?????????? ???? ?? ???????? ???"????????"?? ????????????? ????????/???? ?? ???"????"??? ?? ??????????? ?? ?? ??????????? ?? ?????????????????? ??????????????????? ???????????????? ????????????Discussions???????? ????AcDown??????????????VFPX: GoFish 4 Beta 1: Current beta is Build 144 (released 2011-06-07 ) See the GoFish4 info page for details and video link: http://vfpx.codeplex.com/wikipage?title=GoFishOnTopReplica: Release 3.3.2: Incremental update over 3.3 and 3.3.1. Added Polish language translation (thanks to Jan Romanczyk). Added German language translation (thanks to Eric Hoffmann). Fixed some localization issues.SQL Compact Query Analyzer: Build 0.3.0.0: Beta build of SQL Compact Query Analyzer Features: - Execute SQL Queries against a SQL Server Compact Edition database - Easily edit the contents of the database - Supports SQLCE 3.1, 3.5 and 4.0 Prerequisites: - .NET Framework 4.0ShowUI: Write-UI -in PowerShell: ShowUI: ShowUI is a PowerShell module to help you write rich user interfaces in script.SharePoint 2010 FBA Pack: SharePoint 2010 FBA Pack 1.0.3: Fixed User Management screen when "RequiresQuestionAndAnswer" set to true Reply to Email Address can now be customized User Management page now only displays users that reside in the membership database Web parts have been changed to inherit from System.Web.UI.WebControls.WebParts.WebPart, so that they will display on anonymous application pages For installation and configuration steps see here.Babylon Toolkit: Babylon.Toolkit v1.0.4: Note about samples: In order to run samples, you need to configure visual studio to run them as an "Out-of-browser application". in order to do that, go to the property page of a sample project, go to the Debug tab, and check the "Out-of-browser application" radio. New features : New Effects BasicEffect3Lights (3 dir lights instead of 1 position light) CartoonEffect (work in progress) SkinnedEffect (with normal and specular map support) SplattingEffect (for multi-texturing with smooth ...SizeOnDisk: 1.0.8.2: With installerTerrariViewer: TerrariViewer v2.5: Added new items associated with Terraria v1.0.3 to the character editor. Fixed multiple bugs with Piggy Bank EditorySterling NoSQL OODB for .NET 4.0, Silverlight 4 and 5, and Windows Phone 7: Sterling OODB v1.5: Welcome to the Sterling 1.5 RTM. This version is backwards compatible without modification to the 1.4 beta. For the 1.0, you will need to upgrade your database. Please see this discussion for details. You must modify your 1.0 code for persistence. The 1.5 version defaults to an in-memory driver. To save to isolated storage or use one of the new mechanisms, see the available drivers and pass an instance of the appropriate one to your database (different databases may use different drivers). ...EnhSim: EnhSim 2.4.6 BETA: 2.4.6 BETAThis release supports WoW patch 4.1 at level 85 To use this release, you must have the Microsoft Visual C++ 2010 Redistributable Package installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=A7B7A05E-6DE6-4D3A-A423-37BF0912DB84 To use the GUI you must have the .NET 4.0 Framework installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992 - Added in the proper...Grammar and Spell Checking Plugin for Windows Live Writer: Grammar Checker Plugin v1.0: First version of the grammar checker plugin for Windows Live Writer.patterns & practices: Project Silk: Project Silk Community Drop 10 - June 3, 2011: Changes from previous drop: Many code changes: please see the readme.mht for details. New "Application Notifications" chapter. Updated "Server-Side Implementation" chapter. Guidance Chapters Ready for Review The Word documents for the chapters are included with the source code in addition to the CHM to help you provide feedback. The PDF is provided as a separate download for your convenience. Installation Overview To install and run the reference implementation, you must perform the fol...Claims Based Identity & Access Control Guide: Release Candidate: Highlights of this release This is the release candidate drop of the new "Claims Identity Guide" edition. In this release you will find: All code samples, including all ACS v2: ACS as a Federation Provider - Showing authentication with LiveID, Google, etc. ACS as a FP with Multiple Business Partners. ACS and REST endpoints. Using a WP7 client with REST endpoints. All ACS specific chapters. Two new chapters on SharePoint (SSO and Federation) All revised v1 chapters We are now ...Terraria Map Generator: TerrariaMapTool 1.0.0.4 Beta: 1) Fixed the generated map.html file so that the file:/// is included in the base path. 2) Added the ability to use parallelization during generation. This will cause the program to use as many threads as there are physical cores. 3) Fixed some background overdraw.DotRas: DotRas v1.2 (Version 1.2.4168): This release includes compiled (and signed) versions of the binaries, PDBs, CHM help documentation, along with both C# and VB.NET examples. Please don't forget to rate the release! If you find a bug, please open a work item and give as much description as possible. Stack traces, which operating system(s) you're targeting, and build type is also very helpful for bug hunting. If you find something you believe to be a bug but are not sure, create a new discussion on the discussions board. Thank...BIDS Helper: BIDS Helper 1.5: New Features Duplicate Role feature for SSAS Biml Package Generator feature for SSIS Fixes and Updates Fixes issue with Printer Friendly Dimension Usage not working from the cube right-click menu Integrated new SSIS Expression Editor Control (http://expressioneditor.codeplex.com - v1.0.3.0) SSIS variable move dialog includes improved validation as well as UI enhancements SSIS Expression List now supports variables, constraints and nested objects, as well as UI enhancements New Enab...Caliburn Micro: WPF, Silverlight and WP7 made easy.: Caliburn.Micro v1.1 RTW: Download ContentsDebug and Release Assemblies Samples Changes.txt License.txt Release Highlights For WP7A new Tombstoning API based on ideas from Fluent NHibernate A new Launcher/Chooser API Strongly typed Navigation SimpleContainer included The full phone lifecycle is made easy to work with ie. we figure out whether your app is actually Resurrecting or just Continuing for you For WPFSupport for the Client Profile Better support for WinForms integration All PlatformsA power...VidCoder: 0.9.1: Added color coding to the Log window. Errors are highlighted in red, HandBrake logs are in black and VidCoder logs are in dark blue. Moved enqueue button to the right with the other control buttons. Added logic to report failures when errors are logged during the encode or when the encode finishes prematurely. Added Copy button to Log window. Adjusted audio track selection box to always show the full track name. Changed encode job progress bar to also be colored yellow when the enco...New ProjectsALogger: Alogger is a simple logger for time execution of methods. Uses Postsharp and SQL Server Compact. How to use?? Add Attribute to your method to check their speed of execution and its ready Sample: [AspectLogTime("Category")] private void SpeedMethod(string name) { //do something.. } Is it too simple? Azure WCF with WAS Portsharing: Sample WCF project with an Azure Webrole that supports TCP endpoints on the same port as Web (port 80). This is accomplished with the TCPPortSharing service. This project is a starter project to enable WAS (Windows Activation Service) with Windows Azure.DotNetToscana: DotNetToscana è lo User Group Toscano su .NET, un gruppo senza fini di lucro formato da persone con una forte passione per l’informatica e in particolare per prodotti e tecnologie legate al Microsoft .NET Framework.Email: Email providereriser: sandboxFacturación CFDI para Microempresas: Proyecto que pretende ayudar a la microempresa a realizar su transición de usar factura en papel a formato electrónicoFolder To SharePoint Metadata Migrator (Folders2SP): PowerShell 2.0 script to facilitate migration of SharePoint/Folder structure to a SPS2010 document library using words in the folders to set taxonomy field values, and web services to lookup source metadata and retrieve versions. Use Case: Migrate MOSS library to SPS library.Gestor de tikets de soporte técnico: Una aplicacion basada en ASP.NET que permite gestionar tikets de soporte técnicoGoogle Doc Uploader: Very simple application that allows you to upload documents to your own google document area with the right click of a mouse button.HTML App Host Framework for Phone 7: This is an HTML Application Host framework for building HTML/JavaScript for Windows Phone 7 with mango this will be for HTML5. The framework consists of controls needed to support embed html apps in a standard xap format used by the market place for deploying to phone 7.MOBZKeys: Press a hotkey to expand text fragments in any application. Unobtrusive, fully configurable from the task bar.MVC_imovies: Proyecto de tesis.RandomRat: RandomRat is a program for generating random sets that meet specific criteriaScenario Testing: Scenario Testing is an interactive tool to define your test scenarios by dragging and dropping methods to be tested. It is build using Workflow Foundation 4 (WF 4). The test scenarios can be saved and loaded again for testing.SEProject: SEProject Sharepoint 2010 Diagnostic Log Compression: This sharepoint extention helps you to compress,copy or move sharepoint uls log files to another location with a scheduled time for backup purpose.Snowball: Snowball is an in progress 2D Game Engine written in C#. It uses SlimDX under the covers but the underlying technology is abstracted away from the end user.T24 Project: T24 ProjectTaller Monitor: Taller MonitorTeam Build Deployer: Team Build Deployer makes it easy to deploy web application projects using Team Build 2010. The solution is written in C#, and enhanced build scripts, and enables Team build to use the built in web application deployment packaging configured found in Visual Studio 2010. This solution is intended to make continuous deployment easy and secure and reusable for any Visual Studio 2010 web application.Test SiteDataQuery SharePoint 2010: Software to testing SiteDataQuery Sharepoint 2010TextWrapper: A IIS managed module that enables word wrap of plain text content. Supports GZip and Deflate encoding. This module increases readability of text files that contain long lines.UMC Information System Alumni Center Website: This project is our final task for course Internet Programming II at Study Program of Information System, Faculty of Technology and Science at University of Ma Chung (UMC). UMC is private educational institution, first university in Indonesia applying Microsoft technology thoroughly called the total solution, which established in Malang, East Java, Indonesia. We named our project 'UMC Information System Alumni Center'. It doesn't mean this project is really used to be official website for ...WeatherDotCom Module for Orchard CMS: Using the Weather Channel feeds, you can connect to weather.com and pull in weather conditions for a particular search term. A live working demonstration of this module can be found on my website at jasongaylord.comWindows Phone Essentials: This library is focused on making the common things you have to do in every windows phone application, like persist application settings, use tasks/choosers, log/trace, threading/asynchronous development etc. testable.Wpf .Net Profiler: A .net profiler with wpf and sqlite

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  • C#/.NET Little Wonders: The Useful But Overlooked Sets

    - by James Michael Hare
    Once again we consider some of the lesser known classes and keywords of C#.  Today we will be looking at two set implementations in the System.Collections.Generic namespace: HashSet<T> and SortedSet<T>.  Even though most people think of sets as mathematical constructs, they are actually very useful classes that can be used to help make your application more performant if used appropriately. A Background From Math In mathematical terms, a set is an unordered collection of unique items.  In other words, the set {2,3,5} is identical to the set {3,5,2}.  In addition, the set {2, 2, 4, 1} would be invalid because it would have a duplicate item (2).  In addition, you can perform set arithmetic on sets such as: Intersections: The intersection of two sets is the collection of elements common to both.  Example: The intersection of {1,2,5} and {2,4,9} is the set {2}. Unions: The union of two sets is the collection of unique items present in either or both set.  Example: The union of {1,2,5} and {2,4,9} is {1,2,4,5,9}. Differences: The difference of two sets is the removal of all items from the first set that are common between the sets.  Example: The difference of {1,2,5} and {2,4,9} is {1,5}. Supersets: One set is a superset of a second set if it contains all elements that are in the second set. Example: The set {1,2,5} is a superset of {1,5}. Subsets: One set is a subset of a second set if all the elements of that set are contained in the first set. Example: The set {1,5} is a subset of {1,2,5}. If We’re Not Doing Math, Why Do We Care? Now, you may be thinking: why bother with the set classes in C# if you have no need for mathematical set manipulation?  The answer is simple: they are extremely efficient ways to determine ownership in a collection. For example, let’s say you are designing an order system that tracks the price of a particular equity, and once it reaches a certain point will trigger an order.  Now, since there’s tens of thousands of equities on the markets, you don’t want to track market data for every ticker as that would be a waste of time and processing power for symbols you don’t have orders for.  Thus, we just want to subscribe to the stock symbol for an equity order only if it is a symbol we are not already subscribed to. Every time a new order comes in, we will check the list of subscriptions to see if the new order’s stock symbol is in that list.  If it is, great, we already have that market data feed!  If not, then and only then should we subscribe to the feed for that symbol. So far so good, we have a collection of symbols and we want to see if a symbol is present in that collection and if not, add it.  This really is the essence of set processing, but for the sake of comparison, let’s say you do a list instead: 1: // class that handles are order processing service 2: public sealed class OrderProcessor 3: { 4: // contains list of all symbols we are currently subscribed to 5: private readonly List<string> _subscriptions = new List<string>(); 6:  7: ... 8: } Now whenever you are adding a new order, it would look something like: 1: public PlaceOrderResponse PlaceOrder(Order newOrder) 2: { 3: // do some validation, of course... 4:  5: // check to see if already subscribed, if not add a subscription 6: if (!_subscriptions.Contains(newOrder.Symbol)) 7: { 8: // add the symbol to the list 9: _subscriptions.Add(newOrder.Symbol); 10: 11: // do whatever magic is needed to start a subscription for the symbol 12: } 13:  14: // place the order logic! 15: } What’s wrong with this?  In short: performance!  Finding an item inside a List<T> is a linear - O(n) – operation, which is not a very performant way to find if an item exists in a collection. (I used to teach algorithms and data structures in my spare time at a local university, and when you began talking about big-O notation you could immediately begin to see eyes glossing over as if it was pure, useless theory that would not apply in the real world, but I did and still do believe it is something worth understanding well to make the best choices in computer science). Let’s think about this: a linear operation means that as the number of items increases, the time that it takes to perform the operation tends to increase in a linear fashion.  Put crudely, this means if you double the collection size, you might expect the operation to take something like the order of twice as long.  Linear operations tend to be bad for performance because they mean that to perform some operation on a collection, you must potentially “visit” every item in the collection.  Consider finding an item in a List<T>: if you want to see if the list has an item, you must potentially check every item in the list before you find it or determine it’s not found. Now, we could of course sort our list and then perform a binary search on it, but sorting is typically a linear-logarithmic complexity – O(n * log n) - and could involve temporary storage.  So performing a sort after each add would probably add more time.  As an alternative, we could use a SortedList<TKey, TValue> which sorts the list on every Add(), but this has a similar level of complexity to move the items and also requires a key and value, and in our case the key is the value. This is why sets tend to be the best choice for this type of processing: they don’t rely on separate keys and values for ordering – so they save space – and they typically don’t care about ordering – so they tend to be extremely performant.  The .NET BCL (Base Class Library) has had the HashSet<T> since .NET 3.5, but at that time it did not implement the ISet<T> interface.  As of .NET 4.0, HashSet<T> implements ISet<T> and a new set, the SortedSet<T> was added that gives you a set with ordering. HashSet<T> – For Unordered Storage of Sets When used right, HashSet<T> is a beautiful collection, you can think of it as a simplified Dictionary<T,T>.  That is, a Dictionary where the TKey and TValue refer to the same object.  This is really an oversimplification, but logically it makes sense.  I’ve actually seen people code a Dictionary<T,T> where they store the same thing in the key and the value, and that’s just inefficient because of the extra storage to hold both the key and the value. As it’s name implies, the HashSet<T> uses a hashing algorithm to find the items in the set, which means it does take up some additional space, but it has lightning fast lookups!  Compare the times below between HashSet<T> and List<T>: Operation HashSet<T> List<T> Add() O(1) O(1) at end O(n) in middle Remove() O(1) O(n) Contains() O(1) O(n)   Now, these times are amortized and represent the typical case.  In the very worst case, the operations could be linear if they involve a resizing of the collection – but this is true for both the List and HashSet so that’s a less of an issue when comparing the two. The key thing to note is that in the general case, HashSet is constant time for adds, removes, and contains!  This means that no matter how large the collection is, it takes roughly the exact same amount of time to find an item or determine if it’s not in the collection.  Compare this to the List where almost any add or remove must rearrange potentially all the elements!  And to find an item in the list (if unsorted) you must search every item in the List. So as you can see, if you want to create an unordered collection and have very fast lookup and manipulation, the HashSet is a great collection. And since HashSet<T> implements ICollection<T> and IEnumerable<T>, it supports nearly all the same basic operations as the List<T> and can use the System.Linq extension methods as well. All we have to do to switch from a List<T> to a HashSet<T>  is change our declaration.  Since List and HashSet support many of the same members, chances are we won’t need to change much else. 1: public sealed class OrderProcessor 2: { 3: private readonly HashSet<string> _subscriptions = new HashSet<string>(); 4:  5: // ... 6:  7: public PlaceOrderResponse PlaceOrder(Order newOrder) 8: { 9: // do some validation, of course... 10: 11: // check to see if already subscribed, if not add a subscription 12: if (!_subscriptions.Contains(newOrder.Symbol)) 13: { 14: // add the symbol to the list 15: _subscriptions.Add(newOrder.Symbol); 16: 17: // do whatever magic is needed to start a subscription for the symbol 18: } 19: 20: // place the order logic! 21: } 22:  23: // ... 24: } 25: Notice, we didn’t change any code other than the declaration for _subscriptions to be a HashSet<T>.  Thus, we can pick up the performance improvements in this case with minimal code changes. SortedSet<T> – Ordered Storage of Sets Just like HashSet<T> is logically similar to Dictionary<T,T>, the SortedSet<T> is logically similar to the SortedDictionary<T,T>. The SortedSet can be used when you want to do set operations on a collection, but you want to maintain that collection in sorted order.  Now, this is not necessarily mathematically relevant, but if your collection needs do include order, this is the set to use. So the SortedSet seems to be implemented as a binary tree (possibly a red-black tree) internally.  Since binary trees are dynamic structures and non-contiguous (unlike List and SortedList) this means that inserts and deletes do not involve rearranging elements, or changing the linking of the nodes.  There is some overhead in keeping the nodes in order, but it is much smaller than a contiguous storage collection like a List<T>.  Let’s compare the three: Operation HashSet<T> SortedSet<T> List<T> Add() O(1) O(log n) O(1) at end O(n) in middle Remove() O(1) O(log n) O(n) Contains() O(1) O(log n) O(n)   The MSDN documentation seems to indicate that operations on SortedSet are O(1), but this seems to be inconsistent with its implementation and seems to be a documentation error.  There’s actually a separate MSDN document (here) on SortedSet that indicates that it is, in fact, logarithmic in complexity.  Let’s put it in layman’s terms: logarithmic means you can double the collection size and typically you only add a single extra “visit” to an item in the collection.  Take that in contrast to List<T>’s linear operation where if you double the size of the collection you double the “visits” to items in the collection.  This is very good performance!  It’s still not as performant as HashSet<T> where it always just visits one item (amortized), but for the addition of sorting this is a good thing. Consider the following table, now this is just illustrative data of the relative complexities, but it’s enough to get the point: Collection Size O(1) Visits O(log n) Visits O(n) Visits 1 1 1 1 10 1 4 10 100 1 7 100 1000 1 10 1000   Notice that the logarithmic – O(log n) – visit count goes up very slowly compare to the linear – O(n) – visit count.  This is because since the list is sorted, it can do one check in the middle of the list, determine which half of the collection the data is in, and discard the other half (binary search).  So, if you need your set to be sorted, you can use the SortedSet<T> just like the HashSet<T> and gain sorting for a small performance hit, but it’s still faster than a List<T>. Unique Set Operations Now, if you do want to perform more set-like operations, both implementations of ISet<T> support the following, which play back towards the mathematical set operations described before: IntersectWith() – Performs the set intersection of two sets.  Modifies the current set so that it only contains elements also in the second set. UnionWith() – Performs a set union of two sets.  Modifies the current set so it contains all elements present both in the current set and the second set. ExceptWith() – Performs a set difference of two sets.  Modifies the current set so that it removes all elements present in the second set. IsSupersetOf() – Checks if the current set is a superset of the second set. IsSubsetOf() – Checks if the current set is a subset of the second set. For more information on the set operations themselves, see the MSDN description of ISet<T> (here). What Sets Don’t Do Don’t get me wrong, sets are not silver bullets.  You don’t really want to use a set when you want separate key to value lookups, that’s what the IDictionary implementations are best for. Also sets don’t store temporal add-order.  That is, if you are adding items to the end of a list all the time, your list is ordered in terms of when items were added to it.  This is something the sets don’t do naturally (though you could use a SortedSet with an IComparer with a DateTime but that’s overkill) but List<T> can. Also, List<T> allows indexing which is a blazingly fast way to iterate through items in the collection.  Iterating over all the items in a List<T> is generally much, much faster than iterating over a set. Summary Sets are an excellent tool for maintaining a lookup table where the item is both the key and the value.  In addition, if you have need for the mathematical set operations, the C# sets support those as well.  The HashSet<T> is the set of choice if you want the fastest possible lookups but don’t care about order.  In contrast the SortedSet<T> will give you a sorted collection at a slight reduction in performance.   Technorati Tags: C#,.Net,Little Wonders,BlackRabbitCoder,ISet,HashSet,SortedSet

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  • CodePlex Daily Summary for Wednesday, June 22, 2011

    CodePlex Daily Summary for Wednesday, June 22, 2011Popular ReleasesEpinova.CRMFramework: Epinova.CRMFramework 0.5: Beta Release Candidate. Issues solved in this release: http://crmframework.codeplex.com/workitem/593DropBox Linker: DropBox Linker 1.3: Added "Get links..." dialog, that provides selective public files links copying Get links link added to tray menu as the default option Fixed URL encoding .NET Framework 4.0 Client Profile requiredDotNetNuke® Community Edition: 06.00.00 Beta: Beta 1 (Build 2300) includes many important enhancements to the user experience. The control panel has been updated for easier access to the most important features and additional forms have been adapted to the new pattern. This release also includes many bug fixes that make it more stable than previous CTP releases. Beta ForumsESRI ArcGIS Silverlight Toolkit: June 2011 - v2.2: ESRI ArcGIS Silverlight Toolkit v2.2 New controls added: Attribution Control ScaleLine Control GpsLayer (WinPhone only)Terraria World Viewer: Version 1.4: Update June 21st World file will be stored in memory to minimize chances of Terraria writing to it while we read it. Different set of APIs allow the program to draw the world much quicker. Loading world information (world variables, chest list) won't cause the GUI to freeze at all anymore. Re-introduced the "Filter chests" checkbox: Allow disabling of chest filter/finder so all chest symbos are always drawn. First-time users will have a default world path suggested to them: C:\Users\U...AcDown????? - Anime&Comic Downloader: AcDown????? v3.0 Beta7: ??AcDown???????????????,?????????????????????。????????????????????,??Acfun、Bilibili、???、???、?????,???????????、???????。 AcDown???????????????????????????,???,???????????????????。 AcDown???????C#??,?????"Acfun?????"。 ????32??64? Windows XP/Vista/7 ????????????? ??:????????Windows XP???,?????????.NET Framework 2.0???(x86)?.NET Framework 2.0???(x64),?????"?????????"??? ??????????????,??????????: ??"AcDown?????"????????? ??v3.0 Beta7 ????????????? ???? ?? ????????????????? "??????"?????"?...BlogEngine.NET: BlogEngine.NET 2.5 RC: BlogEngine.NET Hosting - Click Here! 3 Months FREE – BlogEngine.NET Hosting – Click Here! This is a Release Candidate version for BlogEngine.NET 2.5. The most current, stable version of BlogEngine.NET is version 2.0. Find out more about the BlogEngine.NET 2.5 RC here. If you want to extend or modify BlogEngine.NET, you should download the source code. To get started, be sure to check out our installation documentation. If you are upgrading from a previous version, please take a look at ...Microsoft All-In-One Code Framework - a centralized code sample library: All-In-One Code Framework 2011-06-19: Alternatively, you can install Sample Browser or Sample Browser VS extension, and download the code samples from Sample Browser. Improved and Newly Added Examples:For an up-to-date code sample index, please refer to All-In-One Code Framework Sample Catalog. NEW Samples for Windows Azure Sample Description Owner CSAzureStartupTask The sample demonstrates using the startup tasks to install the prerequisites or to modify configuration settings for your environment in Windows Azure Rafe Wu ...IronPython: 2.7.1 Beta 1: This is the first beta release of IronPython 2.7. Like IronPython 54498, this release requires .NET 4 or Silverlight 4. This release will replace any existing IronPython installation. The highlights of this release are: Updated the standard library to match CPython 2.7.2. Add the ast, csv, and unicodedata modules. Fixed several bugs. IronPython Tools for Visual Studio are disabled by default. See http://pytools.codeplex.com for the next generation of Python Visual Studio support. See...Facebook C# SDK: 5.0.40: This is a RTW release which adds new features to v5.0.26 RTW. Support for multiple FacebookMediaObjects in one request. Allow FacebookMediaObjects in batch requests. Removes support for Cassini WebServer (visual studio inbuilt web server). Better support for unit testing and mocking. updated SimpleJson to v0.6 Refer to CHANGES.txt for details. For more information about this release see the following blog posts: Facebook C# SDK - Multiple file uploads in Batch Requests Faceb...Candescent NUI: Candescent NUI (7774): This is the binary version of the source code in change set 7774.EffectControls-Silverlight controls with animation effects: EffectControls: EffectControlsMedia Companion: MC 3.408b weekly: Some minor fixes..... Fixed messagebox coming up during batch scrape Added <originaltitle></originaltitle> to movie nfo's - when a new movie is scraped, the original title will be set as the returned title. The end user can of course change the title in MC, however the original title will not change. The original title can be seen by hovering over the movie title in the right pane of the main movie tab. To update all of your current nfo's to add the original title the same as your current ...NLog - Advanced .NET Logging: NLog 2.0 Release Candidate: Release notes for NLog 2.0 RC can be found at http://nlog-project.org/nlog-2-rc-release-notesPowerGUI Visual Studio Extension: PowerGUI VSX 1.3.5: Changes - VS SDK no longer required to be installed (a bug in v. 1.3.4).Gendering Add-In for Microsoft Office Word 2010: Gendering Add-In: This is the first stable Version of the Gendering Add-In. Unzip the package and start "setup.exe". The .reg file shows how to config an alternate path for suggestion table.Intelligent Enterprise Solution: Document for this project: Document for this projectTerrariViewer: TerrariViewer v3.1 [Terraria Inventory Editor]: This version adds tool tips. Almost every picture box you mouse over will tell you what item is in that box. I have also cleaned up the GUI a little more to make things easier on my end. There are various bug fixes including ones associated with opening different characters in the same instance of the program. As always, please bring any bugs you find to my attention.Kinect Paint: KinectPaint V1.0: This is version 1.0 of Kinect Paint. To run it, follow the steps: Install the Kinect SDK for Windows (available at http://research.microsoft.com/en-us/um/redmond/projects/kinectsdk/download.aspx) Connect your Kinect device to the computer and to the power. Download the Zip file. Unblock the Zip file by right clicking on it, and pressing the Unblock button in the file properties (if available). Extract the content of the Zip file. Run KinectPaint.exe.CommonLibrary.NET: CommonLibrary.NET - 0.9.7 Beta: A collection of very reusable code and components in C# 3.5 ranging from ActiveRecord, Csv, Command Line Parsing, Configuration, Holiday Calendars, Logging, Authentication, and much more. Samples in <root>\src\Lib\CommonLibrary.NET\Samples CommonLibrary.NET 0.9.7Documentation 6738 6503 New 6535 Enhancements 6583 6737New Projects4wheels: ASP.Net MVC 2 applicationAidbrella: A vast number of individuals and organizations are dedicated to alleviating poverty and advancing wellbeing. However, they often lack knowledge as to the actions of others working in their geographical or topical area. Consequently, many aid initiatives often overlap, leading to duplicated efforts and hindering the delivery of fully effective aid. Aidbrella is a community-driven initiative to help them to share information about what they are doing, and where. AIUB CEC Web: A web portal developed for American International University - Bangladesh (http://www.aiub.edu) for their Continuing Education Center department. The website is live at http://cec.aiub.edu. Now it's Open Source and can be used by you! We would just expect to be mentioned. Enjoy!Arduino to Visual Studio converter.: This projet will make coding for arduino easier and faster for people used to Visual Studio Enviromnent with TRUE autocomplete feature. This tool will convert PDE file into a VC++ project that you can compile with Arduino compiler later. Bango Android Application Analytics SDK: Bango application analytics is an analytics solution for mobile applications. This SDK provides a framework you can use in your application to add analytics capabilities to your mobile applications. It's developed in Java and targets the Android operating system.Bango BlackBerry Application Analytics SDK: Bango application analytics is an analytics solution for mobile applications. This SDK provides a framework you can use in your application to add analytics capabilities to your mobile applications. It's developed in Java and targets the RIM BlackBerry operating system.Certificate Authority Policy Module: Certificate Authority Policy ModuleCheckers: Eric and Zach's checkers game.CUDAfy.NET: CUDAfy .NET allows easy development of high performance GPGPU applications completely from the Microsoft .NET framework. It's developed in C#.DotSpatialApp: DotSpatialApp is a UI wrapper around DotSpatial that includes a ribbon and docking panels.FreeLoader: FreeLoader is a dependency-resolving loader for JavaScript.FXTool: Project contains some ideas about remote indicators, remote analytics to Forex trading.Hal.Net: C# Hal parser for .NetLiver: liver MsgPack-SML: SML library for serialize/deserialize along with MessagePack format. Odd Ends: Odd ends, bits and pieces of stuff I think I've needed or think I might need in various situations. Odd Ends is primarily targeted against development in an ASP.NET MVC Framework environment, but can (hopefully) be useful in a bunch of other situations as well.Phoenix Service Bus - Extensions: The purpose of this project is to house various extensions that can be used in conjunction with Phoenix Service Bus. This project is also create to avoid adding extensions that does not relate to the core function/purpose of Phoenix Service BusPS2EXE: This Powershell script let you create an exe file for other PowerShell scripts. The EXE files will execute the PowerShell script you specified.Regionizer: Regionizer is a C# document formatter and code enhancement tool. Install Regionizer by double clicking on the Regionizer.vsix file in the install directory of the Regionizer project; The path to the install is: Regionizer\Install\Regionizer.vsix For Visual Studio 2010 OnlySimple Set for .net: simple set class makes it easier for students of computer science to manage sets and set related operations. It's developed in C#.SQLBK; una solucion para respaldos de SQL Server: SQLBk es una herramienta desarrollada en .NET Framework que permite realizar respaldos de bases de datos SQL Server, comprimirlas y enviarlas a un servidor FTPSuper Find: Super Find is a search utility tool for windows. It searches any type of files in the system very fast.TetrisDota: Classic tetris game with Dota sounds.TFS OData CodePlex Sample for WP7: Sample project to help people use TFS OData Services with Windows Phone 7 and is coded in C#. TravelAgencySystem: TravelAgencySystemWebConsult: Medical consultations provided onlineWebSql: WebSql

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  • CodePlex Daily Summary for Tuesday, October 23, 2012

    CodePlex Daily Summary for Tuesday, October 23, 2012Popular ReleasesDNN Module Creator: 01.01.00: Updated templates for DNN7 ( ie. DAL2, Web Service API ). Numerous bug fixes and enhancements.WPF Application Framework (WAF): WPF Application Framework (WAF) 2.5.0.390: Version 2.5.0.390 (Release Candidate): This release contains the source code of the WPF Application Framework (WAF) and the sample applications. Requirements .NET Framework 4.0 (The package contains a solution file for Visual Studio 2010) The unit test projects require Visual Studio 2010 Professional Changelog Legend: [B] Breaking change; [O] Marked member as obsolete WAF: Fix recent file list remove issue. WAF: Minor code improvements. BookLibrary: Fix Blend design time support o...ltxml.js - LINQ to XML for JavaScript: 1.0 - Beta 1: First release!EvoGame: EvoGame PreAlpha v0.0.2_c InDev: Yup, a new update, go the sprites working.Ficharts.Net: 1.0 Alpha: ??Ficharts????、???????????,?? ??/???、??/???、???、??/???ZXMAK2: Version 2.6.6.0: + fix refresh debugger after open RZX file + add NoFlic video filterSQLLib: Alpha release 17: Added CLR UDFs: * clr.fn_regex_instr - similar to Oracle REGEX_INSTR * clr.fn_regex_substr - similar to Oracle REGEX_SUBSTR To deploy CLR objects copy ClrAgg.dll and ClrRegEx.dll to a folder of you choice (currently deployment script points to C:\Program Files\Microsoft SQL Server\100\CLR\ClrAgg.dll) and execute deployment scripts InstallCLRAggregates.sql and InstallCLRRegEx.sql Thank you for rating the download and/or your feedback.EPiServer CMS ElencySolutions.MultipleProperty: ElencySolutions.MultipleProperty v1.6.3: The ElencySolutions.MulitpleProperty property controls have been developed by Lee Crowe a technical developer at Fortune Cookie (London). Installation notes The property copy page can be locked down by adding the following location element, the path of this will be different depending on whether you use the embedded or non embedded resource version. When installing the nuget package these will be added automatically, examples below: Embedded: <location path="util/ElencySolutionsMultipleP...Fiskalizacija za developere: FiskalizacijaDev 1.1: Ovo je prva nadogradnja ovog projekta nakon inicijalnog predstavljanja - dodali smo nekoliko feature-a, bilo zato što smo sami primijetili da bi ih bilo dobro dodati, bilo na osnovu vaših sugestija - hvala svima koji su se ukljucili :) Ovo su stvari riješene u v1.1.: 1. Bilo bi dobro da se XML dokument koji se šalje u CIS može snimiti u datoteku (http://fiskalizacija.codeplex.com/workitem/612) 2. Podrška za COM DLL (VB6) (http://fiskalizacija.codeplex.com/workitem/613) 3. Podrška za DOS (unu...MCEBuddy 2.x: MCEBuddy 2.3.4: Changelog for 2.3.4 (32bit and 64bit) 1. Fixed a bug introduced in 2.3.3 that would cause HD recordings and recordings with multiple audio channels to fail. 2. Updated <encoder-unsupported> option to compare with all Audio tracks for videos with multiple audio tracks. 3. Fixed a bug with SRT and EDL files, when input and output directory are the same the files are not preserved.BlogEngine.NET: BlogEngine.NET 2.7 RC: Cheap ASP.NET Hosting - $4.95/Month - Click Here!! Click Here for More Info Cheap ASP.NET Hosting - $4.95/Month - Click Here! dot This is a Release Candidate version for BlogEngine.NET 2.7. The most current, stable version of BlogEngine.NET is version 2.6. Find out more about the BlogEngine.NET 2.7 RC here. To get started, be sure to check out our installation documentation. If you are upgrading from a previous version, please take a look at the Upgrading to BlogEngine.NET 2.7 instructions...Pulse: Pulse 0.6.3.0: Fixed a number of bugs that showed up since my update yesterday. Fixes included are for: - Weird issue where the initial "Nature" wallbase.cc search would duplicate itself - After changing a providers settings it wouldn't take affect until you restarted Pulse (removing or adding a provider entirely did take effect though) - Another small issue with the regex for the wallbase.cc wallpapers that I tweaked yesterday, seems good now though.Liberty: v3.4.0.0 Release 20th October 2012: Change Log -Added -Halo 4 support (invincibility, ammo editing) -Reach A warning dialog now shows up when you first attempt to swap a weapon -Fixed -A few minor bugsClosedXML - The easy way to OpenXML: ClosedXML 0.68.1: ClosedXML now resolves formulas! Yes it finally happened. If you call cell.Value and it has a formula the library will try to evaluate the formula and give you the result. For example: var wb = new XLWorkbook(); var ws = wb.AddWorksheet("Sheet1"); ws.Cell("A1").SetValue(1).CellBelow().SetValue(1); ws.Cell("B1").SetValue(1).CellBelow().SetValue(1); ws.Cell("C1").FormulaA1 = "\"The total value is: \" & SUM(A1:B2)"; var...Orchard Project: Orchard 1.6 RC: RELEASE NOTES This is the Release Candidate version of Orchard 1.6. You should use this version to prepare your current developments to the upcoming final release, and report problems. Please read our release notes for Orchard 1.6 RC: http://docs.orchardproject.net/Documentation/Orchard-1-6-Release-Notes Please do not post questions as reviews. Questions should be posted in the Discussions tab, where they will usually get promptly responded to. If you post a question as a review, you wil...Rawr: Rawr 5.0.1: This is the Downloadable WPF version of Rawr!For web-based version see http://elitistjerks.com/rawr.php You can find the version notes at: http://rawr.codeplex.com/wikipage?title=VersionNotes Rawr Addon (NOT UPDATED YET FOR MOP)We now have a Rawr Official Addon for in-game exporting and importing of character data hosted on Curse. The Addon does not perform calculations like Rawr, it simply shows your exported Rawr data in wow tooltips and lets you export your character to Rawr (including ba...Yahoo! UI Library: YUI Compressor for .Net: Version 2.1.1.0 - Sartha (BugFix): - Revered back the embedding of the 2x assemblies.Visual Studio Team Foundation Server Branching and Merging Guide: v2.1 - Visual Studio 2012: Welcome to the Branching and Merging Guide What is new? The Version Control specific discussions have been moved from the Branching and Merging Guide to the new Advanced Version Control Guide. The Branching and Merging Guide and the Advanced Version Control Guide have been ported to the new document style. See http://blogs.msdn.com/b/willy-peter_schaub/archive/2012/10/17/alm-rangers-raising-the-quality-bar-for-documentation-part-2.aspx for more information. Quality-Bar Details Documentatio...D3 Loot Tracker: 1.5.5: Compatible with 1.05.Write Once, Play Everywhere: MonoGame 3.0 (BETA): This is a beta release of the up coming MonoGame 3.0. It contains an Installer which will install a binary release of MonoGame on windows boxes with the following platforms. Windows, Linux, Android and Windows 8. If you need to build for iOS or Mac you will need to get the source code at this time as the installers for those platforms are not available yet. The installer will also install a bunch of Project templates for Visual Studio 2010 , 2012 and MonoDevleop. For those of you wish...New ProjectsAddition of two numbers: Addition of two integer numbersAddTwoNumbers: Add two numbersASP_BANMAYTINH: Xây d?ng web bán máy tính b?ng ASPAvalon MVC: Do not use, still in alphaCaio Proiete's HG Playground: Simple test project to leverage Mercurial features using CodePlexCaio Proiete's TFS Playground: Simple test project to leverage TFS features using CodePlexcodeplexaddproject: Task 1 adding two numbers.Compresor markov orden 1 shannon: Compresor de fuentes basado en el algoritmo de shannon con markov orden 1Cricket Mania: addd39 grid system: A web-based combat grid system for use in play-by-post DnD (or similar) role playing games.DarkSky Tagit: An Orchard module that exposes the jQuery Tagit plugin written by Hailwood as a script resource.DnnExpert: ??? ????? ?? ???? ???? ????? ? ???? ??? ?????? ??? ?? ???? ?? ???? ?? ???????? ???? ?? ???? ??? ???? ?? ?? ? ?????? ????? ???? ? ?????? ? ???? ???? ?? ????.Expandable Text/HTML for DotNetNuke by IowaComputerGurus Inc.: The DNN Expandable Text/HTML module allows you to display multiple text items with the ability to expand and collapse individual items.FarajsWeb2Project: This project is intended to design a Web2.0 website for 7COM0203 ModuleGeminorum Software Contacts for DotNetNuke: A simple contact manager for DotNetNuke.GitText: Test olyGoDarting by Harsh Maurya: Darts Game developed in WPF. requires .Net Framework 4.0Info Gempa BMKG: Aplikasi pembaca informasi gempa BMKGMassive encryption of files: "Massive Encrypt" allows you to encrypt or rename many files at once. Of course you can decrypt later encrypted files!Metal Player: Simple and easy to use, Metal Player has basic multimedia player functions, and some new functions that will enjoy you.NAntDefineTasks: NAnt Define Tasks allows you to define NAnt tasks in terms of other NAnt tasks, instead of having to write any C# code. Nebulosa: Nebulosa is a complete engine to create a complete websitesNigeria Single Mothers: This website project helps single mothers in Nigeria share ideas on how to raise children given the socio-economic and cultural challenges they face.PCV_Clinic_Pro: PCVClinicPro is a software proRendering.NET: Rendering.NET is an abstraction for any visualization device and over several APIs like OpenGL, DirectX, XNA, WebGL, WPF, Silverlight, Mobile DirectX, etc.RLA: A template for illustrate a MVC2 websiteSecure Password Recovery for DotNetNuke by IowaComputerGurus Inc.: IowaComputerGurus's Secure Password Recovery module is the next step in preventing user passwords from being sent via e-mail!SimpleSum: This calculates a simple sum using Visual Basic.SiteCetic: Sitio de CETIC Social Learning: Social Learning Project for BC 2012Towards a generic DSL for modeling page types in WCMSs: An exploration of creating DSLs to facilitate the creation of page models in WCMSs using VMSDK. The concepts of PIM, PSM, DSL, M2M, and M2T will be explored.TrafficArchives: TrafficArchives is a two people group of TrafficArchives team, in this project ,we will use asp.net do Traffic Archives information manager system.UnivDevs: university test developmentUppityUp: UppityUp is a simple and light-weight tray application which monitors a remote server and shows a notification when it comes online. This is useful when you need to connect to a server that is currently down and you want to be notified the moment it becomes available.uurrooster: Hier wordt nog aan gewerktUWE Computer Science: A collection of all work submitted and completed during my course at UWE - Bristol.ViewMyDeals: This Site is all about sharing dramatic deals and offers of several products using Promotional codes and vouchers .WebUntis4Win8: WebUntis4Win8X.MetaWeblog.Model: This is a model for MetaWeblog API. Detail info at: http://xmlrpc.scripting.com/metaWeblogApi.html http://en.wikipedia.org/wiki/MetaWeblogXPath execution utility: CommonXPath is a utility to execute an XPath expression on some XML and see the result.

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  • CodePlex Daily Summary for Friday, January 21, 2011

    CodePlex Daily Summary for Friday, January 21, 2011Popular ReleasesTweetSharp: TweetSharp v2.0.0.0 - Preview 9: Documentation for this release may be found at http://tweetsharp.codeplex.com/wikipage?title=UserGuide&referringTitle=Documentation. Note: This code is currently preview quality. Preview 9 ChangesAdded support for lists and suggested users Fixes based on user feedback Third Party Library VersionsHammock v1.1.6: http://hammock.codeplex.com Json.NET 4.0 Release 1: http://json.codeplex.comjqGrid ASP.Net MVC Control: Version 1.2.0.0: jqGrid 3.8 support jquery 1.4 support New and exciting features Many bugfixes Complete separation from the jquery, & jqgrid codeMediaScout: MediaScout 3.0 Preview 4: Update ReleaseCoding4Fun Tools: Coding4Fun.Phone.Toolkit v1: Coding4Fun.Phone.Toolkit v1MFCMAPI: January 2011 Release: Build: 6.0.0.1024 Full release notes at SGriffin's blog. If you just want to run the tool, get the executable. If you want to debug it, get the symbol file and the source. The 64 bit build will only work on a machine with Outlook 2010 64 bit installed. All other machines should use the 32 bit build, regardless of the operating system. Facebook BadgeAutoLoL: AutoLoL v1.5.4: Added champion: Renekton Removed automatic file association Fix: The recent files combobox didn't always open a file when an item was selected Fix: Removing a recently opened file caused an errorRazorEngine: RazorEngine v2.0: IMPORTANT RazorEngine v2 is a complete rewrite of the templating framework. Because of this, there are no guarantees that code written around v1.2 will run without modification. The v2 framework is cleaner and refined. Please check the forthcoming codeplex site updates which will detail the new functionality. Features in v2: ASP.NET Medium Trust Support Custom Template Activation with Dependency Injection Support Subtemplating using the new @Include method. Known issues: @Include doe...DotNetNuke® Community Edition: 05.06.01: Major Highlights Fixed issue to remove preCondition checks when upgrading to .Net 4.0 Fixed issue where some valid domains were failing email validation checks. Fixed issue where editing Host menu page settings assigns the page to a Portal. Fixed issue which caused XHTML validation problems in 5.6.0 Fixed issue where an aspx page in any subfolder was inaccessible. Fixed issue where Config.Touch method signature had an unintentional breaking change in 5.6.0 Fixed issue which caused...MiniTwitter: 1.65: MiniTwitter 1.65 ???? ?? List ????? in-reply-to ???????? ????????????????????????? ?? OAuth ????????????????????????????ASP.net Ribbon: Version 2.1: Tadaaa... So Version 2.1 brings a lot of things... Have a look at the homepage to see what's new. Also, I wanted to (really) improve the Designer. I wanted to add great things... but... it took to much time. And as some of you were waiting for fixes, I decided just to fix bugs and add some features. So have a look at the demo app to see new features. Thanks ! (You can expect some realeses if bugs are not fixed correctly... 2.2, 2.3, 2.4....)iTracker Asp.Net Starter Kit: Version 3.0.0: This is the inital release of the version 3.0.0 Visual Studio 2010 (.Net 4.0) remake of the ITracker application. I connsider this a working, stable application but since there are still some features missing to make it "complete" I'm leaving it listed as a "beta" release. I am hoping to make it feature complete for v3.1.0 but anything is possible.ASP.NET MVC Project Awesome, jQuery Ajax helpers (controls): 1.6.1: A rich set of helpers (controls) that you can use to build highly responsive and interactive Ajax-enabled Web applications. These helpers include Autocomplete, AjaxDropdown, Lookup, Confirm Dialog, Popup Form, Popup and Pager changes: RenderView controller extension works for razor also live demo switched to razorBloodSim: BloodSim - 1.3.3.1: - Priority update to resolve a bug that was causing Boss damage to ignore Blood Shields entirelyRawr: Rawr 4.0.16 Beta: Rawr is now web-based. The link to use Rawr4 is: http://elitistjerks.com/rawr.phpThis is the Cataclysm Beta Release. More details can be found at the following link http://rawr.codeplex.com/Thread/View.aspx?ThreadId=237262 As of this release, you can now also begin using the new Downloadable WPF version of Rawr!This is a pre-alpha release of the WPF version, there are likely to be a lot of issues. If you have a problem, please follow the Posting Guidelines and put it into the Issue Tracker. W...MvcContrib: an Outer Curve Foundation project: MVC 3 - 3.0.51.0: Please see the Change Log for a complete list of changes. MVC BootCamp Description of the releases: MvcContrib.Release.zip MvcContrib.dll MvcContrib.TestHelper.dll MvcContrib.Extras.Release.zip T4MVC. The extra view engines / controller factories and other functionality which is in the project. This file includes the main MvcContrib assembly. Samples are included in the release. You do not need MvcContrib if you download the Extras.Yahoo! UI Library: YUI Compressor for .Net: Version 1.5.0.0 - Jalthi: Updated solution to VS2010. New: Work Item #4450 - Optional MSBuild task parameter :: Do not error if no files were found. Fixed: Work Item #5028 - Output file encoding is the same as the optional MSBuild task encoding argument. Fixed: Work Item #5824 - MSBuilds where slow, after the first build due to the Current Thread being forced to en-gb, on none en-gb systems. Changed: Work Item #6873 - Project license changed from MS-PL to GPLv2. New: Added all the unit tests from the Java YU...N2 CMS: 2.1.1: N2 is a lightweight CMS framework for ASP.NET. It helps you build great web sites that anyone can update. 2.1.1 Maintenance release List of changes 2.1 Major Changes Support for auto-implemented properties ({get;set;}, based on contribution by And Poulsen) File manager improvements (multiple file upload, resize images to fit) New image gallery Infinite scroll paging on news Content templates First time with N2? Try the demo site Download one of the template packs (above) and open...VidCoder: 0.8.1: Adds ability to choose an arbitrary range (in seconds or frames) to encode. Adds ability to override the title number in the output file name when enqueing multiple titles. Updated presets: Added iPhone 4, Apple TV 2, fixed some existing presets that should have had weightp=0 or trellis=0 on them. Added {parent} option to auto-name format. Use {parent:2} to refer to a folder 2 levels above the input file. Added {title:2} option to auto-name format. Adds leading zeroes to reach the sp...Microsoft SQL Server Product Samples: Database: AdventureWorks2008R2 without filestream: This download contains a version of the AdventureWorks2008R2 OLTP database without FILESTREAM properties. You do not need to have filestream enabled to attach this database. No additional schema or data changes have been made. To install the version of AdventureWorks2008R2 that includes filestream, use the SR1 installer available here. Prerequisites: Microsoft SQL Server 2008 R2 must be installed. Full-Text Search must be enabled. Installing the AdventureWorks2008R2 OLTP database: 1. Cl...ASP.NET: ASP.NET MVC 3 Application Upgrader: This standalone application upgrades ASP.NET MVC 2 applications to ASP.NET MVC 3. It works for both ASP.NET MVC 3 RC 2 and RTM. The tool only supports Visual Studio 2010 solutions and MVC 2 projects targeting .NET 4. It will not work with VS 2008 solutions, MVC 1 projects, or projects targeting .NET 3.5. Those projects will first have to be upgraded using Visual Studio 2010 and/or retargeted for .NET 4. The tool will: Create a backup of your entire solution Update all Web Applications and ...New ProjectsAppCore: Setup application to create core components and services for .NET applications. The goal of AppCore is to provide a developer friendly installation that will let a dev choose an application type, dependency injection framework, testing and mocking framework, object relational mAsp.Net Performance: Asp.Net Performance?????????Asp.Net?????????????,?????????????????,??????????,???????????,???Issue Tracker????.BizTalk Context Adder Pipeline Component (BRE): BizTalk Context Property Adder pipeline component, which utilize BizTalk Rule Engine configuration.BKM: BKM is a software system to convert Arabic sign language to speech using computer vision technique developed by ROSHAR team as graduation project from computer science department supervised by Dr.Mohammad AnsariBlackJack: BlackJack is a Littel Game like 17+4. It's developed in VB.NET and WPF4. It is a Training Application from me to learn VB.NET and WPF4. C# RushHour Puzzle: RushHour Project uses the A* algorithm to solve instances of the Rush Hour puzzle. This involved implementing a graph-search version of A*, along with three heuristics, and testing the implementation on several Rush Hour puzzlesCoding4Fun Tools: This is a set of tools to make people's lifes easier. First up: Windows Phone 7 SilverlightEBP: Enterprise Basis Platform. Include Application Management, User Management, File Management, Permission, Workflow, Forms, Reporting, SSO, Real-Time Message, etc. It's developed in C#, based on .NET Framework 4.0.ETL with Talend for Aras Innovator PLM: This project is answering a lot of request about Aras Innovator on starting to use this PLM solution in a Pilot Project. The Aras migration tool is more advanced but reserved to subscribers. Using the Open Source ETL Talend Open Suite we will help to migrate any data to Aras.hg5build17501: hg5build17501Manager: The Multifunctional manager: -Friends -Contacts -Numbers -Websites -Credit cards/bank accounts -Passwords -Accounts (games/websites/forums) -Books -Magazines -Discs -MoremelodyMe - Unlimited Music Streaming: melodyMe is an application that allows music lovers to take their Music Library with them without needing to copy the music and install other software. This application uses internet sources to try and find tracks from servers on the web. It's developed in C#.Mint: Mint is a framework enabling fast and flexible modular programming in .NET Framework.navPic@Zure: navPic@Zure is simple photo sharing portal. This is project is purely aimed to create an end to end application to understand and get the hands dirty on Cloud technologies like Windows Azure, SQL Auzre, App Fabric etc...NHibernate 3.0 SQL Logger: NH3SQLLogger is a lightweight NHibernate 3 SQL Logger, with SQL Formatting, Caller methods loggings and Syntax highlighting.openPMU SynchroPhasor Sensor Project: openPMU is a Phasor Measurement Unit (PMU) sensor used to measure SynchroPhasors. The openPMU project's goal is to provide an open source PMU sensor that can be used for experimentation and, research. The openPMU sensor is developed for compatibility with the openPDC project.Orchard Typekit Module: A Typekit module for Orchard.PL_Fahrradverleih: PL_FahrradVerleih PMS ProjektSharePoint 2010 Social Connector: Project in draft.SimuMill3C: This is a 3C milling simulation software with error detection and G-Code generationSmart Skelta Web Logger: Smart Skelta Web logger is an alternative and web based solution for Skelta Logger Console.Since its web based application, many users can able to access simultaneously.It supports filtering the log items based on repository,workflow,etc. and user can navigate to old log entries.TeamWebSite: Sample code for the Team Web Site Application built with ASP.NET 4, Code First EF 4 and SQL CE 4.TextTemplate: A text templating class library for .NET 3.5 and 4.0 written in C#.tfs 2010 work item RSS Feed: tfs 2010 work item RSS Feed you can see work item assigned to you or to your subordinates and updates on work items you have createdTIMESHARE: N/AVB CPCC Class: I will be posting my projects for my class hererWindows Phone 7 Bing Maps CloudMade TileSource Sample: This project is designed to be a sample of how you can use Custom map tiles provided by CloudMade.com in the Bing Maps Windows Phone 7 Control. This give you the benefit of using one of the many thousands of pre created map styles at CloudMade.com or creating your own map styleZicuer: Test zicuer site??? ???: ????????? ???????

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  • CodePlex Daily Summary for Thursday, November 22, 2012

    CodePlex Daily Summary for Thursday, November 22, 2012Popular ReleasesStackBuilder: StackBuilder 1.0.11.0: +Added Box/Case analysis...VidCoder: 1.4.7 Beta: Added view modes to the Preview window. Now you can see the image in 1:1 or in "Corners" mode to show a close-up of cropping results. Added the ability to set a custom completion sound. Gave the encoding settings command bar a more distinctive background color and extended it to the whole width of the window. Added the preview button to the command bar. Rearranged UI in Video tab and added back the section headers. Added the "Most" choice for the advanced x264 analysis option. Updat...ServiceMon - Extensible Real-time, Service Monitoring Utility for Windows: ServiceMon Release 1.2.0.58: Auto-uploaded from build serverImapX 2: ImapX 2.0.0.6: An updated release of the ImapX 2 library, containing many bugfixes for both, the library and the sample application.WiX Toolset: WiX v3.7 RC: WiX v3.7 RC (3.7.1119.0) provides feature complete Bundle update and reference tracking plus several bug fixes. For more information see Rob's blog post about the release: http://robmensching.com/blog/posts/2012/11/20/WiX-v3.7-Release-Candidate-availablePicturethrill: Version 2.11.20.0: Fixed up Bing image provider on Windows 8Excel AddIn to reset the last worksheet cell: XSFormatCleaner.xla: Modified the commandbar code to use CommandBar IDs instead of English names.Json.NET: Json.NET 4.5 Release 11: New feature - Added ITraceWriter, MemoryTraceWriter, DiagnosticsTraceWriter New feature - Added StringEscapeHandling with options to escape HTML and non-ASCII characters New feature - Added non-generic JToken.ToObject methods New feature - Deserialize ISet<T> properties as HashSet<T> New feature - Added implicit conversions for Uri, TimeSpan, Guid New feature - Missing byte, char, Guid, TimeSpan and Uri explicit conversion operators added to JToken New feature - Special case...EntitiesToDTOs - Entity Framework DTO Generator: EntitiesToDTOs.v3.0: DTOs and Assemblers can be generated inside project folders! Choose the types you want to generate! Support for Visual Studio 2012 !!! Support for new Entity Framework EDMX (format used by VS2012) ! Support for Enum Types! Optional automatic check for updates! Added the following methods to Assemblers! IEnumerable<DTO>.ToEntities() : ICollection<Entity> IEnumerable<Entity>.ToDTOs() : ICollection<DTO> Indicate class identifier for DTOs and Assemblers! Cleaner Assemblers code....mojoPortal: 2.3.9.4: see release notes on mojoportal.com http://www.mojoportal.com/mojoportal-2394-released Note that we have separate deployment packages for .NET 3.5 and .NET 4.0, but we recommend you to use .NET 4, we will probably drop support for .NET 3.5 once .NET 4.5 is available The deployment package downloads on this page are pre-compiled and ready for production deployment, they contain no C# source code and are not intended for use in Visual Studio. To download the source code see getting the lates...DotNetNuke® Store: 03.01.07: What's New in this release? IMPORTANT: this version requires DotNetNuke 04.06.02 or higher! DO NOT REPORT BUGS HERE IN THE ISSUE TRACKER, INSTEAD USE THE DotNetNuke Store Forum! Bugs corrected: - Replaced some hard coded references to the default address provider classes by the corresponding interfaces to allow the creation of another address provider with a different name. New Features: - Added the 'pickup' delivery option at checkout. - Added the 'no delivery' option in the Store Admin ...Bundle Transformer - a modular extension for ASP.NET Web Optimization Framework: Bundle Transformer 1.6.10: Version: 1.6.10 Published: 11/18/2012 Now almost all of the Bundle Transformer's assemblies is signed (except BundleTransformer.Yui.dll); In BundleTransformer.SassAndScss the SassAndCoffee.Ruby library was replaced by my own implementation of the Sass- and SCSS-compiler (based on code of the SassAndCoffee.Ruby library version 2.0.2.0); In BundleTransformer.CoffeeScript added support of CoffeeScript version 1.4.0-3; In BundleTransformer.TypeScript added support of TypeScript version 0....ExtJS based ASP.NET 2.0 Controls: FineUI v3.2.0: +2012-11-18 v3.2.0 -?????????????????SelectedValueArray????????(◇?◆:)。 -???????????????????RecoverPropertiesFromJObject????(〓?〓、????、??、Vian_Pan)。 -????????????,?????????????,???SelectedValueArray???????(sam.chang)。 -??Alert.Show???????????(swtseaman)。 -???????????????,??Icon??IconUrl????(swtseaman)。 -?????????TimePicker(??)。 -?????????,??/res.axd?css=blue.css&v=1。 -????????,?????????????,???????。 -????MenuCheckBox(???????)。 -?RadioButton??AutoPostBack??。 -???????FCKEditor?????????...BugNET Issue Tracker: BugNET 1.2: Please read our release notes for BugNET 1.2: http://blog.bugnetproject.com/bugnet-1-2-has-been-released Please do not post questions as reviews. Questions should be posted in the Discussions tab, where they will usually get promptly responded to. If you post a question as a review, you will pollute the rating, and you won't get an answer.Paint.NET PSD Plugin: 2.2.0: Changes: Layer group visibility is now applied to all layers within the group. This greatly improves the visual fidelity of complex PSD files that have hidden layer groups. Layer group names are prefixed so that users can get an indication of the layer group hierarchy. (Paint.NET has a flat list of layers, so the hierarchy is flattened out on load.) The progress bar now reports status when saving PSD files, instead of showing an indeterminate rolling bar. Performance improvement of 1...CRM 2011 Visual Ribbon Editor: Visual Ribbon Editor (1.3.1116.7): [IMPROVED] Detailed error message descriptions for FaultException [FIX] Fixed bug in rule CrmOfflineAccessStateRule which had incorrect State attribute name [FIX] Fixed bug in rule EntityPropertyRule which was missing PropertyValue attribute [FIX] Current connection information was not displayed in status bar while refreshing list of entitiesSuper Metroid Randomizer: Super Metroid Randomizer v5: v5 -Added command line functionality for automation purposes. -Implented Krankdud's change to randomize the Etecoon's item. NOTE: this version will not accept seeds from a previous version. The seed format has changed by necessity. v4 -Started putting version numbers at the top of the form. -Added a warning when suitless Maridia is required in a parsed seed. v3 -Changed seed to only generate filename-legal characters. Using old seeds will still work exactly the same. -Files can now be saved...Caliburn Micro: WPF, Silverlight, WP7 and WinRT/Metro made easy.: Caliburn.Micro v1.4: Changes This version includes many bug fixes across all platforms, improvements to nuget support and...the biggest news of all...full support for both WinRT and WP8. Download Contents Debug and Release Assemblies Samples Readme.txt License.txt Packages Available on Nuget Caliburn.Micro – The full framework compiled into an assembly. Caliburn.Micro.Start - Includes Caliburn.Micro plus a starting bootstrapper, view model and view. Caliburn.Micro.Container – The Caliburn.Micro invers...DirectX Tool Kit: November 15, 2012: November 15, 2012 Added support for WIC2 when available on Windows 8 and Windows 7 with KB 2670838 Cleaned up warning level 4 warningsDotNetNuke® Community Edition CMS: 06.02.05: Major Highlights Updated the system so that it supports nested folders in the App_Code folder Updated the Global Error Handling so that when errors within the global.asax handler happen, they are caught and shown in a page displaying the original HTTP error code Fixed issue that stopped users from specifying Link URLs that open on a new window Security FixesFixed issue in the Member Directory module that could show members to non authenticated users Fixed issue in the Lists modul...New Projects1122case1325: It is a codeplex project1122case1327: Never be so greedy Accommodation Portal: This is a skeleton web site for holiday home owners, who wishes to rent their holiday accommodations to visitors from around the world. Analog Clock: This is project contains analog clock made in win forms.Android Socket Plus: ????Android??????。???????Android???????Socket???,?????????(?PC?Windows????????)??????Socket???,??,????????????;??????????????Socket???,??????????????Socket???。Bancosol: PFCBig Data Twitter Demo: This demo analyzes tweets in real-time, even including a dashboard. The tweets are also archived in Azure DB/Blob and Hadoop where Excel can be used for BI!Cloud For Science: This project serves as issue tracker for C4S components, and is used by participants of the C4S project. cwt: cwtDiary Application for Elementary Student: A Simple Diary Application Made for Elementary Student. Dice Dreams: Dice Dreams Dice Dreams is a dice game , the player must get 1.000.000 point to win, you start with 100.000 point. Dynamic Entity Framework Filtering: Generates linq to Entity Framework Queries by examining the EF data model, thus allowing for code reduction for queries to commonly requested entities.EazyErp: Enterprise Resource Planning System of Vf AsiaGoPlay: Tooke - add a project description here...HMyBlog: myblogHumanitarian Toolbox: This project is the publication site for bits built by the Humanitarian Toolbox ( http://humanitariantoolbox.net/).Impulse Media Player: Impulse Media Player is the ultimate media player for WindowsInspiration.Web: Description: A simple (but entertaining) ASP.NET MVC (C#) project to suggest random code names for projects. Intended audience: People who need a name (any name) to get started with their projects. Application written during Webcamp Singapore (4th Jun 2010 - 5th Jun 2010).iPictureUploader: Simple tool to upload images onto WEB and share via blogs/forums/etc lugionline: test projectMosaic Snake 3D: A clone of the popular Snake game for Windows 8. It contains a simple 3D engine based on SharpDX and is completely written in C# and Xaml.Outage Display: A simple web-based outage displayPrestaShop free Electronic Brown Shop Template - ModuleBazaar: Check out Latest and Best Featured PrestaShop Templates, Modules Magento Extensions, Opencart Extensions, Clone scripts from ModuleBazaarRackspace Cloud Files Manager: A simple Rackspace Cloud Files manager for static websitesRoll The Dice: Roll The Dice is a simple game developed by Erika Enggar Savitri and Queen Anugerah Aguslia who are currently studying Information System at Ma Chung UniversityRussian IDM: Russian IDM is free IdM solutionshootout: Comparing the speed of different languages and the constructs available within those languagessmart messaging connector: Sending fax from a PrintDocument or a file. Sending broadcast fax. Managing (Pause/Resume/Restart) current fax job. Managing configuration of the fax serverTeen Diary: Teen Diary Software - FREEWARE SOFTWARE. - SIMPLE, LIGHTWEIGHT, PORTABLE, COMPATIBLE. - made from .NET FRAMEWORK languange with XML data. Tekapo: Tekapo is a wizard style application that will help you manage your digital photos. Most digital cameras will store images as JPEG files. Information about the camera and how the camera has taken the photo is placed into the JPEG file along with the image data. One of the pieces of information stored is the date and time that the photo was taken. Tekapo uses the picture taken date to organise the photos.The Byte Kitchen's Open Sources: This project is related to The Byte Kitchen Blog (at thebytekitchen.com). It typically deals with Windows 8 apps, DirectX, and the Kinect for Windows.TheDiary: daily-self journalWCFsample: WCFsampleXNA Game Editor: This project will has familiar features like Unity Engine Editor.

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  • CodePlex Daily Summary for Friday, October 25, 2013

    CodePlex Daily Summary for Friday, October 25, 2013Popular Releases7zbackup - PowerShell Script to Backup Files with 7zip: 7zBackup v. 1.9.5 Stable: Do you like this piece of software ? It took some time and effort to develop. Please consider a helping me with a donation Or please visit my blog Code : Rewritten the launcher of 7zip whith "old" fashioned batch. Better handling of exit codes Feat : New argument --notifyextra to drive the way extra information is delivered with the notification log Bug : NoFollowJunctions switch was inverted Feat : Added new directives maxfilesize and minfilesize to enhance file selection upon their ...Gac Library -- C++ Utilities for GPU Accelerated GUI and Script: Gaclib 0.5.5.0: Gaclib.zip contains the following content GacUIDemo Demo solution and projects Public Source GacUI library Document HTML document. Please start at reference_gacui.html Content Necessary CSS/JPG files for document. Improvements to the previous release Add 1 demos Editor.Toolstrip.Document Added new features GuiDocumentViewer and GuiDocumentLabel is editable like an RichTextEdit control.PowerShell App Deployment Toolkit: PowerShell App Deployment Toolkit v3.0.7: This is a bug fix release, containing some important fixes! Fixed issue where Session 0 was not detected correctly, resulting in issues when attempting to display a UI when none was allowed Fixed Installation Prompt and Installation Restart Prompt appearing when deploy mode was non-interactive or silent Fixed issue where defer prompt is displayed after force closing multiple applications Fixed issue executing blocked app execution dialog from UNC path (executed instead from local tempo...BlackJumboDog: Ver5.9.7: 2013.10.24 Ver5.9.7 (1)FTP???????、2?????????????shift-jis????????????? (2)????HTTP????、???????POST??????????????????CtrlAltStudio Viewer: CtrlAltStudio Viewer 1.1.0.34322 Alpha 4: This experimental release of the CtrlAltStudio Viewer includes the following significant features: Oculus Rift support. Stereoscopic 3D display support. Based on Firestorm viewer 4.4.2 codebase. For more details, see the release notes linked to below. Release notes: http://ctrlaltstudio.com/viewer/release-notes/1-1-0-34322-alpha-4 Support info: http://ctrlaltstudio.com/viewer/support Privacy policy: http://ctrlaltstudio.com/viewer/privacy Disclaimer: This software is not provided or sup...ImapX 2: ImapX 2.0.0.13: The long awaited ImapX 2.0.0.13 release. The library has been rewritten from scratch, massive optimizations and refactoring done. Several new features introduced. Added support for Mono. Added support for Windows Phone 7.1 and 8.0 Added support for .Net 2.0, 3.0 Simplified connecting to server by reducing the number of parameters and adding automatic port selection. Changed authentication handling to be universal and allowing to build custom providers. Added advanced server featur...VsTortoise - a TortoiseSVN add-in for Microsoft Visual Studio: VsTortoise Build 32 Beta: Note: This release does not work with custom VsTortoise toolbars. These get removed every time when you shutdown Visual Studio. (#7940) This release has been tested with Visual Studio 2008, 2010, 2012 and 2013, using TortoiseSVN 1.6, 1.7 and 1.8. It should also still work with Visual Studio 2005, but I couldn't find anyone to test it in VS2005. Build 32 (beta) changelogNew: Added Visual Studio 2013 support New: Added Visual Studio 2012 support New: Added SVN 1.8 support New: Added 'Ch...ABCat: ABCat v.2.0.1a: ?????????? ???????? ? ?????????? ?????? ???? ??? Win7. ????????? ?????? ????????? ?? ???????. ????? ?????, ???? ????? ???????? ????????? ?????????? ????????? "?? ??????? ????? ???????????? ?????????? ??????...", ?? ?????????? ??????? ? ?????????? ?????? Microsoft SQL Ce ?? ????????? ??????: http://www.microsoft.com/en-us/download/details.aspx?id=17876. ???????? ?????? x64 ??? x86 ? ??????????? ?? ?????? ???????????? ???????. ??? ??????? ????????? ?? ?????????? ?????? Entity Framework, ? ???? ...patterns & practices: Data Access Guidance: Data Access Guidance 2013: This is the 2013 release of Data Access Guidance. The documentation for this RI is also available on MSDN: Data Access for Highly-Scalable Solutions: Using SQL, NoSQL, and Polyglot Persistence: http://msdn.microsoft.com/en-us/library/dn271399.aspxMedia Companion: Media Companion MC3.584b: IMDB changes fixed. Fixed* mc_com.exe - Fixed to using new profile entries. * Movie - fixed rename movie and folder if use foldername selected. * Movie - Alt Edit Movie, trailer url check if changed and confirm valid. * Movie - Fixed IMDB poster scraping * Movie - Fixed outline and Plot scraping, including removal of Hyperlink's. * Movie Poster refactoring, attempts to catch gdi+ errors Revision HistoryJayData -The unified data access library for JavaScript: JayData 1.3.4: JayData is a unified data access library for JavaScript to CRUD + Query data from different sources like WebAPI, OData, MongoDB, WebSQL, SQLite, HTML5 localStorage, Facebook or YQL. The library can be integrated with KendoUI, Angular.js, Knockout.js or Sencha Touch 2 and can be used on Node.js as well. See it in action in this 6 minutes video KendoUI examples: JayData example site Examples for map integration JayData example site What's new in JayData 1.3.4 For detailed release notes check ...TerrariViewer: TerrariViewer v7.2 [Terraria Inventory Editor]: Added "Check for Update" button Hopefully fixed Windows XP issue You can now backspace in Item stack fieldsVirtual Wifi Hotspot for Windows 7 & 8: Virtual Router Plus 2.6.0: Virtual Router Plus 2.6.0Fast YouTube Downloader: Fast YouTube Downloader 2.3.0: Fast YouTube DownloaderMagick.NET: Magick.NET 6.8.7.101: Magick.NET linked with ImageMagick 6.8.7.1. Breaking changes: - Renamed Matrix classes: MatrixColor = ColorMatrix and MatrixConvolve = ConvolveMatrix. - Renamed Depth method with Channels parameter to BitDepth and changed the other method into a property.VidCoder: 1.5.9 Beta: Added Rip DVD and Rip Blu-ray AutoPlay actions for Windows: now you can have VidCoder start up and scan a disc when you insert it. Go to Start -> AutoPlay to set it up. Added error message for Windows XP users rather than letting it crash. Removed "quality" preset from list for QSV as it currently doesn't offer much improvement. Changed installer to ignore version number when copying files over. Should reduce the chances of a bug from me forgetting to increment a version number. Fixed ...MSBuild Extension Pack: October 2013: Release Blog Post The MSBuild Extension Pack October 2013 release provides a collection of over 480 MSBuild tasks. A high level summary of what the tasks currently cover includes the following: System Items: Active Directory, Certificates, COM+, Console, Date and Time, Drives, Environment Variables, Event Logs, Files and Folders, FTP, GAC, Network, Performance Counters, Registry, Services, Sound Code: Assemblies, AsyncExec, CAB Files, Code Signing, DynamicExecute, File Detokenisation, GUI...VG-Ripper & PG-Ripper: VG-Ripper 2.9.49: changes NEW: Added Support for "ImageTeam.org links NEW: Added Support for "ImgNext.com" links NEW: Added Support for "HostUrImage.com" links NEW: Added Support for "3XVintage.com" linksmyCollections: Version 2.8.7.0: New in this version : Added Public Rating Added Collection Number Added Order by Collection Number Improved XBMC integrations Play on music item will now launch default player. Settings are now saved in database. Tooltip now display sort information. Fix Issue with Stars on card view. Fix Bug with PDF Export. Fix Bug with technical information's. Fix HotMovies Provider. Improved Performance on Save. Bug FixingMoreTerra (Terraria World Viewer): MoreTerra 1.11.3.1: Release 1.11.3.1 ================ = New Features = ================ Added markers for Copper Cache, Silver Cache and the Enchanted Sword. ============= = Bug Fixes = ============= Use Official Colors now no longer tries to change the Draw Wires option instead. World reading was breaking for people with a stock 1.2 Terraria version. Changed world name reading so it does not crash the program if you load MoreTerra while Terraria is saving the world. =================== = Feature Removal = =...New ProjectsAdder: Adder is simply converter for WPF binding. They add a value from parameter to target if a target int or double, concatenate parameter and value if type a strinAir Control ATV: App for Windows Phone to remote control Apple TV with FireCore aTV Flash (or Black) and AirControl installed.Bangladeshi Open Source Windows 8/Phone Apps: The largest Bangladeshi Open Source project with a vision. Mostly community-contributed Windows 8 and Windows Phone apps.BTB: Tumor board presentation tool for oncologyBulletin: not completed yet. the basic functions are ready, though.CRM Dashboard for Lync: Dynamics CRM Dashboard for Lync is an add-on that makes both applications seamlessly communicate between one another.Crowd CMS: Crowd CMS - A Crowd Funded Web Content Management System Built Using ASP.Net MVC 4 Website: http://www.crowdcms.co.uk CrowdCube: http://goo.gl/Mnd1Xsdusanproject: It is a project for Web Scripting and Application Development (COM), School of Computer of Science, University of HertfordshireElectronic Integrated Disease Surveillance System (EIDSS™) - Web Version: EIDSS can be configured as an electronic disease surveillance network, implemented in a region, to support public health practitioners and epidemiologists.Facebook Login Tool: Facebook Login ToolGadgeteer interface: Project aimed at creating common wrappers and interfaces for common components. This would allow for building applications based on the interfaces, this should Madoko: Madoko is a fast javascript Markdown processor written in Koka. It can render beautiful HTML and PDF (via LaTeX) and supports many Markdown extensions.MinotaurTeam: Project Management System using ASP.NET MVCmobSocial: Open Source Social Network for free!Online Room Reservation for Exchange: When you have Microsoft Exchange Server and meeting rooms you share with people from outside your company this is the ideal application for you.Pescar2013-shop-Masapan: aproyecto_Andy_y_Meli: mely and andyQMachine: A platform for World Wide Computingquarkz: It's just a try-out of Visual C++ (on example of Windows Forms Application). In this project I tried out to re-write one simple Flash game called quarkz in VC++TFS Workspaces Cleaner: TFS Workspaces Cleaner deletes Team Foundation Server workspaces that have not been accessed in a number of days, along with their files locally on disk.Ticketing System With ASP.NET MVC: Ticketing System where visitors (without authentication) should be able to view most commented tickets, as well as to register and login in the system. RegisterTotalFreedom Angular JS MVC: This library provides more tight integration between C# classes and AngularJS, helps to those who prefer to use as much C# and as little JavaScript as possiblevWordToHtml: vWordToHtmlvwpHistory: vwpHistoryweibowinform: weibowinformweibowinformweibowinformweibowinformweibowinformweibowinformweibowinformweibowinformweibowinformweibowinformweibowinformXompare - XML files comparison: Xompare - XML files comparison

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  • Stumbling Through: Visual Studio 2010 (Part I)

    Ive spent the better part of the last two years doing nothing but K2 workflow development, which until very recently could only be done in Visual Studio 2005 so I am a bit behind the times. I seem to have skipped over using Visual Studio 2008 entirely, and I am now ready to stumble through all that Ive missed. Not that I will abandon my K2 ramblings, but I need to get back to some of the other technologies I am passionate about but havent had the option of working with them on a day-to-day basis as I have with K2 blackpearl. Specifically, I am going to be focusing my efforts on what is new in the Entity Framework and WPF in Visual Studio 2010, though you have to keep in mind that since I have skipped VS 2008, I may be giving VS 2010 credit for things that really have been around for a while (hey, if I havent seen it, it is new to me!). I have the following simple goals in mind for this exercise: Entity Framework Model an inherited class Entity Framework Model a lookup entity WPF Bind a list of entities WPF - on selection of an entity in the bound list, display values of the selected entity WPF For the lookup field, provide a dropdown of potential values to lookup All of these goals must be accomplished using as little code as possible, relying on the features we get out of the box in Visual Studio 2010. This isnt going to be rocket science here, Im not even looking to get or save this data from/to a data source, but I gotta start somewhere and hopefully it will grow into something more interesting. For this exercise, I am going to try to model some fictional data about football players and personnel (maybe turning this into some sort of NFL simulation game if I lose my job and can play with this all day), so Ill start with a Person class that has a name property, and extend that with a Player class to include a Position lookup property. The idea is that a Person can be a Player, Coach or whatever other personnel type may be associated with a football team but well only flesh out the Player aspect of a person for this. So to get started, I fired up Visual Studio 2010 and created a new WPF Application: To this project, I added a new ADO.NET Entity Data Model named PlayerModel (for now, not sure what will be an appropriate name so this may be revisited): I chose for it to be an empty model, as I dont have a database designed for this yet: Using the toolbox, I dragged out an entity for each of the items we identified earlier: Person, Player and Position, and gave them some simple properties (note that I kept the default Id property for each of them): Now to figure out how to link these things together the way I want to first, lets try to tell it that Player extends Person. I see that Inheritance is one of the items in the toolbox, but I cant seem to drag it out anywhere onto the canvas. However, when I right-click an element, I get the option to Add Inheritance to it, which gives us exactly what we want: Ok, now that we have that, how do we tell it that each player has a position? Well, despite association being in the toolbox, I have learned that you cant just drag and drop those elements so I right click Player and select Add -> Association to get the following dialog: I see the option here to Add foreign key properties to my entities Ive read somewhere this this is a new and highly-sought after feature so Ill see what it does. Selecting it includes a PositionId on the Player element for me, which seems pretty database-centric and I would like to see if I can live without it for now given that we also got the Position property out of this association. Ill bring it back into the fold if it ends up being useful later. Here is what we end up with now: Trying to compile this resulted in an error stating that the Player entity cannot have an Id, because the Person element it extends already has a property named Id. Makes sense, so I remove it and compile again. Success, but with a warning but success is a good thing so Ill pretend I didnt see that warning for now. It probably has to do with the fact that my Player entity is now pretty useless as it doesnt have any non-navigation properties. So things seem to match what we are going for, great now what the heck do we do with this? Lets switch gears and see what we get for free dealing with this model from the UI. Lets open up the MainWindow.xaml and see if we can connect to our entities as a data source. Hey, whats this? Have you read my mind, Visual Studio? Our entities are already listed in the Data Sources panel: I do notice, however, that our Player entity is missing. Is this due to that compilation warning? Ill add a bogus property to our player entity just to see if that is the case no, still no love. The warning reads: Error 2062: No mapping specified for instances of the EntitySet and AssociationSet in the EntityContainer PlayerModelContainer. Well if everything worked without any issues, then I wouldnt be stumbling through at all, so lets get to the bottom of this. My good friend google indicates that the warning is due to the model not being tied up to a database. Hmmm, so why dont Players show up in my data sources? A little bit of drill-down shows that they are, in fact, exposed under Positions: Well now that isnt quite what I want. While you could get to players through a position, it shouldnt be that way exclusively. Oh well, I can ignore that for now lets drag Players out onto the canvas after selecting List from the dropdown: Hey, what the heck? I wanted a list not a listview. Get rid of that list view that was just dropped, drop in a listbox and then drop the Players entity into it. That will bind it for us. Of course, there isnt any data to show, which brings us to the really hacky part of all this and that is to stuff some test data into our view source without actually getting it from any data source. To do this through code, we need to grab a reference to the positionsPlayersViewSource resource that was created for us when we dragged out our Players entity. We then set the source of that reference equal to a populated list of Players.  Well add a couple of players that way as well as a few positions via the positionsViewSource resource, and Ill ensure that each player has a position specified.  Ultimately, the code looks like this: System.Windows.Data.CollectionViewSource positionViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("positionsViewSource")));             List<Position> positions = new List<Position>();             Position newPosition = new Position();             newPosition.Id = 0;             newPosition.Name = "WR";             positions.Add(newPosition);             newPosition = new Position();             newPosition.Id = 1;             newPosition.Name = "RB";             positions.Add(newPosition);             newPosition = new Position();             newPosition.Id = 2;             newPosition.Name = "QB";             positions.Add(newPosition);             positionViewSource.Source = positions;             System.Windows.Data.CollectionViewSource playerViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("positionsPlayersViewSource")));             List<Player> players = new List<Player>();             Player newPlayer = new Player();             newPlayer.Id = 0;             newPlayer.Name = "Test Dude";             newPlayer.Position = positions[0];             players.Add(newPlayer);             newPlayer = new Player();             newPlayer.Id = 1;             newPlayer.Name = "Test Dude II";             newPlayer.Position = positions[1];             players.Add(newPlayer);             newPlayer = new Player();             newPlayer.Id = 2;             newPlayer.Name = "Test Dude III";             newPlayer.Position = positions[2];             players.Add(newPlayer);             playerViewSource.Source = players; Now that our views are being loaded with data, we can go about tying things together visually. Drop a text box (to show the selected players name) and a combo box (to show the selected players position). Drag the Positions entity from the data sources panel to the combo box to wire it up to the positions view source. Click the text box that was dragged, and find its Text property in the properties pane. There is a little glyph next to it that displays Advanced Properties when hovered over click this and then select Apply Data Binding. In the dialog that appears, we can select the current players name as the value to bind to: Similarly, we can wire up the combo boxs SelectedItem value to the current players position: When the application is executed and we navigate through the various players, we automatically get their name and position bound to the appropriate fields: All of this was accomplished with no code save for loading the test data, and I might add, it was pretty intuitive to do so via the drag and drop of entities straight from the data sources panel. So maybe all of this was old hat to you, but I was very impressed with this experience and I look forward to stumbling through the caveats of doing more complex data modeling and binding in this fashion. Next up, I suppose, will be figuring out how to get the entities to get real data from a data source instead of stuffing it with test data as well as trying to figure out why Players ended up being under Positions in the data sources panel.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • .NET Code Evolution

    - by Alois Kraus
    Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/07/24/153504.aspxAt my day job I do look at a lot of code written by other people. Most of the code is quite good and some is even a masterpiece. And there is also code which makes you think WTF… oh it was written by me. Hm not so bad after all. There are many excuses reasons for bad code. Most often it is time pressure followed by not enough ambition (who cares) or insufficient training. Normally I do care about code quality quite a lot which makes me a (perceived) slow worker who does write many tests and refines the code quite a lot because of the design deficiencies. Most of the deficiencies I do find by putting my design under stress while checking for invariants. It does also help a lot to step into the code with a debugger (sometimes also Windbg). I do this much more often when my tests are red. That way I do get a much better understanding what my code really does and not what I think it should be doing. This time I do want to show you how code can evolve over the years with different .NET Framework versions. Once there was  time where .NET 1.1 was new and many C++ programmers did switch over to get rid of not initialized pointers and memory leaks. There were also nice new data structures available such as the Hashtable which is fast lookup table with O(1) time complexity. All was good and much code was written since then. At 2005 a new version of the .NET Framework did arrive which did bring many new things like generics and new data structures. The “old” fashioned way of Hashtable were coming to an end and everyone used the new Dictionary<xx,xx> type instead which was type safe and faster because the object to type conversion (aka boxing) was no longer necessary. I think 95% of all Hashtables and dictionaries use string as key. Often it is convenient to ignore casing to make it easy to look up values which the user did enter. An often followed route is to convert the string to upper case before putting it into the Hashtable. Hashtable Table = new Hashtable(); void Add(string key, string value) { Table.Add(key.ToUpper(), value); } This is valid and working code but it has problems. First we can pass to the Hashtable a custom IEqualityComparer to do the string matching case insensitive. Second we can switch over to the now also old Dictionary type to become a little faster and we can keep the the original keys (not upper cased) in the dictionary. Dictionary<string, string> DictTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); void AddDict(string key, string value) { DictTable.Add(key, value); } Many people do not user the other ctors of Dictionary because they do shy away from the overhead of writing their own comparer. They do not know that .NET has for strings already predefined comparers at hand which you can directly use. Today in the many core area we do use threads all over the place. Sometimes things break in subtle ways but most of the time it is sufficient to place a lock around the offender. Threading has become so mainstream that it may sound weird that in the year 2000 some guy got a huge incentive for the idea to reduce the time to process calibration data from 12 hours to 6 hours by using two threads on a dual core machine. Threading does make it easy to become faster at the expense of correctness. Correct and scalable multithreading can be arbitrarily hard to achieve depending on the problem you are trying to solve. Lets suppose we want to process millions of items with two threads and count the processed items processed by all threads. A typical beginners code might look like this: int Counter; void IJustLearnedToUseThreads() { var t1 = new Thread(ThreadWorkMethod); t1.Start(); var t2 = new Thread(ThreadWorkMethod); t2.Start(); t1.Join(); t2.Join(); if (Counter != 2 * Increments) throw new Exception("Hmm " + Counter + " != " + 2 * Increments); } const int Increments = 10 * 1000 * 1000; void ThreadWorkMethod() { for (int i = 0; i < Increments; i++) { Counter++; } } It does throw an exception with the message e.g. “Hmm 10.222.287 != 20.000.000” and does never finish. The code does fail because the assumption that Counter++ is an atomic operation is wrong. The ++ operator is just a shortcut for Counter = Counter + 1 This does involve reading the counter from a memory location into the CPU, incrementing value on the CPU and writing the new value back to the memory location. When we do look at the generated assembly code we will see only inc dword ptr [ecx+10h] which is only one instruction. Yes it is one instruction but it is not atomic. All modern CPUs have several layers of caches (L1,L2,L3) which try to hide the fact how slow actual main memory accesses are. Since cache is just another word for redundant copy it can happen that one CPU does read a value from main memory into the cache, modifies it and write it back to the main memory. The problem is that at least the L1 cache is not shared between CPUs so it can happen that one CPU does make changes to values which did change in meantime in the main memory. From the exception you can see we did increment the value 20 million times but half of the changes were lost because we did overwrite the already changed value from the other thread. This is a very common case and people do learn to protect their  data with proper locking.   void Intermediate() { var time = Stopwatch.StartNew(); Action acc = ThreadWorkMethod_Intermediate; var ar1 = acc.BeginInvoke(null, null); var ar2 = acc.BeginInvoke(null, null); ar1.AsyncWaitHandle.WaitOne(); ar2.AsyncWaitHandle.WaitOne(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Intermediate did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Intermediate() { for (int i = 0; i < Increments; i++) { lock (this) { Counter++; } } } This is better and does use the .NET Threadpool to get rid of manual thread management. It does give the expected result but it can result in deadlocks because you do lock on this. This is in general a bad idea since it can lead to deadlocks when other threads use your class instance as lock object. It is therefore recommended to create a private object as lock object to ensure that nobody else can lock your lock object. When you read more about threading you will read about lock free algorithms. They are nice and can improve performance quite a lot but you need to pay close attention to the CLR memory model. It does make quite weak guarantees in general but it can still work because your CPU architecture does give you more invariants than the CLR memory model. For a simple counter there is an easy lock free alternative present with the Interlocked class in .NET. As a general rule you should not try to write lock free algos since most likely you will fail to get it right on all CPU architectures. void Experienced() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); t1.Wait(); t2.Wait(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Experienced did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Experienced() { for (int i = 0; i < Increments; i++) { Interlocked.Increment(ref Counter); } } Since time does move forward we do not use threads explicitly anymore but the much nicer Task abstraction which was introduced with .NET 4 at 2010. It is educational to look at the generated assembly code. The Interlocked.Increment method must be called which does wondrous things right? Lets see: lock inc dword ptr [eax] The first thing to note that there is no method call at all. Why? Because the JIT compiler does know very well about CPU intrinsic functions. Atomic operations which do lock the memory bus to prevent other processors to read stale values are such things. Second: This is the same increment call prefixed with a lock instruction. The only reason for the existence of the Interlocked class is that the JIT compiler can compile it to the matching CPU intrinsic functions which can not only increment by one but can also do an add, exchange and a combined compare and exchange operation. But be warned that the correct usage of its methods can be tricky. If you try to be clever and look a the generated IL code and try to reason about its efficiency you will fail. Only the generated machine code counts. Is this the best code we can write? Perhaps. It is nice and clean. But can we make it any faster? Lets see how good we are doing currently. Level Time in s IJustLearnedToUseThreads Flawed Code Intermediate 1,5 (lock) Experienced 0,3 (Interlocked.Increment) Master 0,1 (1,0 for int[2]) That lock free thing is really a nice thing. But if you read more about CPU cache, cache coherency, false sharing you can do even better. int[] Counters = new int[12]; // Cache line size is 64 bytes on my machine with an 8 way associative cache try for yourself e.g. 64 on more modern CPUs void Master() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Master, 0); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Master, Counters.Length - 1); t1.Wait(); t2.Wait(); Counter = Counters[0] + Counters[Counters.Length - 1]; if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Master did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Master(object number) { int index = (int) number; for (int i = 0; i < Increments; i++) { Counters[index]++; } } The key insight here is to use for each core its own value. But if you simply use simply an integer array of two items, one for each core and add the items at the end you will be much slower than the lock free version (factor 3). Each CPU core has its own cache line size which is something in the range of 16-256 bytes. When you do access a value from one location the CPU does not only fetch one value from main memory but a complete cache line (e.g. 16 bytes). This means that you do not pay for the next 15 bytes when you access them. This can lead to dramatic performance improvements and non obvious code which is faster although it does have many more memory reads than another algorithm. So what have we done here? We have started with correct code but it was lacking knowledge how to use the .NET Base Class Libraries optimally. Then we did try to get fancy and used threads for the first time and failed. Our next try was better but it still had non obvious issues (lock object exposed to the outside). Knowledge has increased further and we have found a lock free version of our counter which is a nice and clean way which is a perfectly valid solution. The last example is only here to show you how you can get most out of threading by paying close attention to your used data structures and CPU cache coherency. Although we are working in a virtual execution environment in a high level language with automatic memory management it does pay off to know the details down to the assembly level. Only if you continue to learn and to dig deeper you can come up with solutions no one else was even considering. I have studied particle physics which does help at the digging deeper part. Have you ever tried to solve Quantum Chromodynamics equations? Compared to that the rest must be easy ;-). Although I am no longer working in the Science field I take pride in discovering non obvious things. This can be a very hard to find bug or a new way to restructure data to make something 10 times faster. Now I need to get some sleep ….

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  • C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

    - by James Michael Hare
    Once again we consider some of the lesser known classes and keywords of C#.  In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>.  Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>.  Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework.  And out of this framework emerged the System.Collections namespace, and it was good.  It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections.  The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever!  With generics the C# language finally got an equivalent of the very powerful C++ templates.  As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections.  The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on.  The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well.  So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them.  The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required.  Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11:  12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20:  21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner.  Looking at  today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes.  With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe.  This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations.  Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5:  6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9:  10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17:  18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock.  With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level).  So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently!  For example, what if you have a Dictionary that has frequent reads but in-frequent updates?  Do you want to lock down the entire Dictionary for every access?  This would be overkill and would prevent concurrent reads.  In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell).  This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in.  The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null.  Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to.  Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic.  For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty!  This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models.  I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts.  Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration).  Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container.  If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations.  This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek().  This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed.  Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items.  Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6:  7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10:  11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call.  That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call.  This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: var results = stack.GetEnumerator(); 7:  8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10:  11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct.  You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all.  In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class.  The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays.  Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart.  Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count.  This results overall in a O(1) complexity which is quite good.  It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue.  There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue().  Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results.  Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5:  6: var iterator = queue.GetEnumerator(); 7:  8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10:  11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious.  Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation.  This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5:  6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12:  13: results.Enqueue(result); 14: }); 15:  16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here.   Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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  • Extending NerdDinner: Adding Geolocated Flair

    - by Jon Galloway
    NerdDinner is a website with the audacious goal of “Organizing the world’s nerds and helping them eat in packs.” Because nerds aren’t likely to socialize with others unless a website tells them to do it. Scott Hanselman showed off a lot of the cool features we’ve added to NerdDinner lately during his popular talk at MIX10, Beyond File | New Company: From Cheesy Sample to Social Platform. Did you miss it? Go ahead and watch it, I’ll wait. One of the features we wanted to add was flair. You know about flair, right? It’s a way to let folks who like your site show it off in their own site. For example, here’s my StackOverflow flair: Great! So how could we add some of this flair stuff to NerdDinner? What do we want to show? If we’re going to encourage our users to give up a bit of their beautiful website to show off a bit of ours, we need to think about what they’ll want to show. For instance, my StackOverflow flair is all about me, not StackOverflow. So how will this apply to NerdDinner? Since NerdDinner is all about organizing local dinners, in order for the flair to be useful it needs to make sense for the person viewing the web page. If someone visits from Egypt visits my blog, they should see information about NerdDinners in Egypt. That’s geolocation – localizing site content based on where the browser’s sitting, and it makes sense for flair as well as entire websites. So we’ll set up a simple little callout that prompts them to host a dinner in their area: Hopefully our flair works and there is a dinner near your viewers, so they’ll see another view which lists upcoming dinners near them: The Geolocation Part Generally website geolocation is done by mapping the requestor’s IP address to a geographic area. It’s not an exact science, but I’ve always found it to be pretty accurate. There are (at least) three ways to handle it: You pay somebody like MaxMind for a database (with regular updates) that sits on your server, and you use their API to do lookups. I used this on a pretty big project a few years ago and it worked well. You use HTML 5 Geolocation API or Google Gears or some other browser based solution. I think those are cool (I use Google Gears a lot), but they’re both in flux right now and I don’t think either has a wide enough of an install base yet to rely on them. You might want to, but I’ve heard you do all kinds of crazy stuff, and sometimes it gets you in trouble. I don’t mean talk out of line, but we all laugh behind your back a bit. But, hey, it’s up to you. It’s your flair or whatever. There are some free webservices out there that will take an IP address and give you location information. Easy, and works for everyone. That’s what we’re doing. I looked at a few different services and settled on IPInfoDB. It’s free, has a great API, and even returns JSON, which is handy for Javascript use. The IP query is pretty simple. We hit a URL like this: http://ipinfodb.com/ip_query.php?ip=74.125.45.100&timezone=false … and we get an XML response back like this… <?xml version="1.0" encoding="UTF-8"?> <Response> <Ip>74.125.45.100</Ip> <Status>OK</Status> <CountryCode>US</CountryCode> <CountryName>United States</CountryName> <RegionCode>06</RegionCode> <RegionName>California</RegionName> <City>Mountain View</City> <ZipPostalCode>94043</ZipPostalCode> <Latitude>37.4192</Latitude> <Longitude>-122.057</Longitude> </Response> So we’ll build some data transfer classes to hold the location information, like this: public class LocationInfo { public string Country { get; set; } public string RegionName { get; set; } public string City { get; set; } public string ZipPostalCode { get; set; } public LatLong Position { get; set; } } public class LatLong { public float Lat { get; set; } public float Long { get; set; } } And now hitting the service is pretty simple: public static LocationInfo HostIpToPlaceName(string ip) { string url = "http://ipinfodb.com/ip_query.php?ip={0}&timezone=false"; url = String.Format(url, ip); var result = XDocument.Load(url); var location = (from x in result.Descendants("Response") select new LocationInfo { City = (string)x.Element("City"), RegionName = (string)x.Element("RegionName"), Country = (string)x.Element("CountryName"), ZipPostalCode = (string)x.Element("CountryName"), Position = new LatLong { Lat = (float)x.Element("Latitude"), Long = (float)x.Element("Longitude") } }).First(); return location; } Getting The User’s IP Okay, but first we need the end user’s IP, and you’d think it would be as simple as reading the value from HttpContext: HttpContext.Current.Request.UserHostAddress But you’d be wrong. Sorry. UserHostAddress just wraps HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"], but that doesn’t get you the IP for users behind a proxy. That’s in another header, “HTTP_X_FORWARDED_FOR". So you can either hit a wrapper and then check a header, or just check two headers. I went for uniformity: string SourceIP = string.IsNullOrEmpty(Request.ServerVariables["HTTP_X_FORWARDED_FOR"]) ? Request.ServerVariables["REMOTE_ADDR"] : Request.ServerVariables["HTTP_X_FORWARDED_FOR"]; We’re almost set to wrap this up, but first let’s talk about our views. Yes, views, because we’ll have two. Selecting the View We wanted to make it easy for people to include the flair in their sites, so we looked around at how other people were doing this. The StackOverflow folks have a pretty good flair system, which allows you to include the flair in your site as either an IFRAME reference or a Javascript include. We’ll do both. We have a ServicesController to handle use of the site information outside of NerdDinner.com, so this fits in pretty well there. We’ll be displaying the same information for both HTML and Javascript flair, so we can use one Flair controller action which will return a different view depending on the requested format. Here’s our general flow for our controller action: Get the user’s IP Translate it to a location Grab the top three upcoming dinners that are near that location Select the view based on the format (defaulted to “html”) Return a FlairViewModel which contains the list of dinners and the location information public ActionResult Flair(string format = "html") { string SourceIP = string.IsNullOrEmpty( Request.ServerVariables["HTTP_X_FORWARDED_FOR"]) ? Request.ServerVariables["REMOTE_ADDR"] : Request.ServerVariables["HTTP_X_FORWARDED_FOR"]; var location = GeolocationService.HostIpToPlaceName(SourceIP); var dinners = dinnerRepository. FindByLocation(location.Position.Lat, location.Position.Long). OrderByDescending(p => p.EventDate).Take(3); // Select the view we'll return. // Using a switch because we'll add in JSON and other formats later. string view; switch (format.ToLower()) { case "javascript": view = "JavascriptFlair"; break; default: view = "Flair"; break; } return View( view, new FlairViewModel { Dinners = dinners.ToList(), LocationName = string.IsNullOrEmpty(location.City) ? "you" : String.Format("{0}, {1}", location.City, location.RegionName) } ); } Note: I’m not in love with the logic here, but it seems like overkill to extract the switch statement away when we’ll probably just have two or three views. What do you think? The HTML View The HTML version of the view is pretty simple – the only thing of any real interest here is the use of an extension method to truncate strings that are would cause the titles to wrap. public static string Truncate(this string s, int maxLength) { if (string.IsNullOrEmpty(s) || maxLength <= 0) return string.Empty; else if (s.Length > maxLength) return s.Substring(0, maxLength) + "..."; else return s; }   So here’s how the HTML view ends up looking: <%@ Page Title="" Language="C#" Inherits="System.Web.Mvc.ViewPage<FlairViewModel>" %> <%@ Import Namespace="NerdDinner.Helpers" %> <%@ Import Namespace="NerdDinner.Models" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Nerd Dinner</title> <link href="/Content/Flair.css" rel="stylesheet" type="text/css" /> </head> <body> <div id="nd-wrapper"> <h2 id="nd-header">NerdDinner.com</h2> <div id="nd-outer"> <% if (Model.Dinners.Count == 0) { %> <div id="nd-bummer"> Looks like there's no Nerd Dinners near <%:Model.LocationName %> in the near future. Why not <a target="_blank" href="http://www.nerddinner.com/Dinners/Create">host one</a>?</div> <% } else { %> <h3> Dinners Near You</h3> <ul> <% foreach (var item in Model.Dinners) { %> <li> <%: Html.ActionLink(String.Format("{0} with {1} on {2}", item.Title.Truncate(20), item.HostedBy, item.EventDate.ToShortDateString()), "Details", "Dinners", new { id = item.DinnerID }, new { target = "_blank" })%></li> <% } %> </ul> <% } %> <div id="nd-footer"> More dinners and fun at <a target="_blank" href="http://nrddnr.com">http://nrddnr.com</a></div> </div> </div> </body> </html> You’d include this in a page using an IFRAME, like this: <IFRAME height=230 marginHeight=0 src="http://nerddinner.com/services/flair" frameBorder=0 width=160 marginWidth=0 scrolling=no></IFRAME> The Javascript view The Javascript flair is written so you can include it in a webpage with a simple script include, like this: <script type="text/javascript" src="http://nerddinner.com/services/flair?format=javascript"></script> The goal of this view is very similar to the HTML embed view, with a few exceptions: We’re creating a script element and adding it to the head of the document, which will then document.write out the content. Note that you have to consider if your users will actually have a <head> element in their documents, but for website flair use cases I think that’s a safe bet. Since the content is being added to the existing page rather than shown in an IFRAME, all links need to be absolute. That means we can’t use Html.ActionLink, since it generates relative routes. We need to escape everything since it’s being written out as strings. We need to set the content type to application/x-javascript. The easiest way to do that is to use the <%@ Page ContentType%> directive. <%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<NerdDinner.Models.FlairViewModel>" ContentType="application/x-javascript" %> <%@ Import Namespace="NerdDinner.Helpers" %> <%@ Import Namespace="NerdDinner.Models" %> document.write('<script>var link = document.createElement(\"link\");link.href = \"http://nerddinner.com/content/Flair.css\";link.rel = \"stylesheet\";link.type = \"text/css\";var head = document.getElementsByTagName(\"head\")[0];head.appendChild(link);</script>'); document.write('<div id=\"nd-wrapper\"><h2 id=\"nd-header\">NerdDinner.com</h2><div id=\"nd-outer\">'); <% if (Model.Dinners.Count == 0) { %> document.write('<div id=\"nd-bummer\">Looks like there\'s no Nerd Dinners near <%:Model.LocationName %> in the near future. Why not <a target=\"_blank\" href=\"http://www.nerddinner.com/Dinners/Create\">host one</a>?</div>'); <% } else { %> document.write('<h3> Dinners Near You</h3><ul>'); <% foreach (var item in Model.Dinners) { %> document.write('<li><a target=\"_blank\" href=\"http://nrddnr.com/<%: item.DinnerID %>\"><%: item.Title.Truncate(20) %> with <%: item.HostedBy %> on <%: item.EventDate.ToShortDateString() %></a></li>'); <% } %> document.write('</ul>'); <% } %> document.write('<div id=\"nd-footer\"> More dinners and fun at <a target=\"_blank\" href=\"http://nrddnr.com\">http://nrddnr.com</a></div></div></div>'); Getting IP’s for Testing There are a variety of online services that will translate a location to an IP, which were handy for testing these out. I found http://www.itouchmap.com/latlong.html to be most useful, but I’m open to suggestions if you know of something better. Next steps I think the next step here is to minimize load – you know, in case people start actually using this flair. There are two places to think about – the NerdDinner.com servers, and the services we’re using for Geolocation. I usually think about caching as a first attack on server load, but that’s less helpful here since every user will have a different IP. Instead, I’d look at taking advantage of Asynchronous Controller Actions, a cool new feature in ASP.NET MVC 2. Async Actions let you call a potentially long-running webservice without tying up a thread on the server while waiting for the response. There’s some good info on that in the MSDN documentation, and Dino Esposito wrote a great article on Asynchronous ASP.NET Pages in the April 2010 issue of MSDN Magazine. But let’s think of the children, shall we? What about ipinfodb.com? Well, they don’t have specific daily limits, but they do throttle you if you put a lot of traffic on them. From their FAQ: We do not have a specific daily limit but queries that are at a rate faster than 2 per second will be put in "queue". If you stay below 2 queries/second everything will be normal. If you go over the limit, you will still get an answer for all queries but they will be slowed down to about 1 per second. This should not affect most users but for high volume websites, you can either use our IP database on your server or we can whitelist your IP for 5$/month (simply use the donate form and leave a comment with your server IP). Good programming practices such as not querying our API for all page views (you can store the data in a cookie or a database) will also help not reaching the limit. So the first step there is to save the geolocalization information in a time-limited cookie, which will allow us to look up the local dinners immediately without having to hit the geolocation service.

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  • PTLQueue : a scalable bounded-capacity MPMC queue

    - by Dave
    Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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  • Informed TDD &ndash; Kata &ldquo;To Roman Numerals&rdquo;

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/05/28/informed-tdd-ndash-kata-ldquoto-roman-numeralsrdquo.aspxIn a comment on my article on what I call Informed TDD (ITDD) reader gustav asked how this approach would apply to the kata “To Roman Numerals”. And whether ITDD wasn´t a violation of TDD´s principle of leaving out “advanced topics like mocks”. I like to respond with this article to his questions. There´s more to say than fits into a commentary. Mocks and TDD I don´t see in how far TDD is avoiding or opposed to mocks. TDD and mocks are orthogonal. TDD is about pocess, mocks are about structure and costs. Maybe by moving forward in tiny red+green+refactor steps less need arises for mocks. But then… if the functionality you need to implement requires “expensive” resource access you can´t avoid using mocks. Because you don´t want to constantly run all your tests against the real resource. True, in ITDD mocks seem to be in almost inflationary use. That´s not what you usually see in TDD demonstrations. However, there´s a reason for that as I tried to explain. I don´t use mocks as proxies for “expensive” resource. Rather they are stand-ins for functionality not yet implemented. They allow me to get a test green on a high level of abstraction. That way I can move forward in a top-down fashion. But if you think of mocks as “advanced” or if you don´t want to use a tool like JustMock, then you don´t need to use mocks. You just need to stand the sight of red tests for a little longer ;-) Let me show you what I mean by that by doing a kata. ITDD for “To Roman Numerals” gustav asked for the kata “To Roman Numerals”. I won´t explain the requirements again. You can find descriptions and TDD demonstrations all over the internet, like this one from Corey Haines. Now here is, how I would do this kata differently. 1. Analyse A demonstration of TDD should never skip the analysis phase. It should be made explicit. The requirements should be formalized and acceptance test cases should be compiled. “Formalization” in this case to me means describing the API of the required functionality. “[D]esign a program to work with Roman numerals” like written in this “requirement document” is not enough to start software development. Coding should only begin, if the interface between the “system under development” and its context is clear. If this interface is not readily recognizable from the requirements, it has to be developed first. Exploration of interface alternatives might be in order. It might be necessary to show several interface mock-ups to the customer – even if that´s you fellow developer. Designing the interface is a task of it´s own. It should not be mixed with implementing the required functionality behind the interface. Unfortunately, though, this happens quite often in TDD demonstrations. TDD is used to explore the API and implement it at the same time. To me that´s a violation of the Single Responsibility Principle (SRP) which not only should hold for software functional units but also for tasks or activities. In the case of this kata the API fortunately is obvious. Just one function is needed: string ToRoman(int arabic). And it lives in a class ArabicRomanConversions. Now what about acceptance test cases? There are hardly any stated in the kata descriptions. Roman numerals are explained, but no specific test cases from the point of view of a customer. So I just “invent” some acceptance test cases by picking roman numerals from a wikipedia article. They are supposed to be just “typical examples” without special meaning. Given the acceptance test cases I then try to develop an understanding of the problem domain. I´ll spare you that. The domain is trivial and is explain in almost all kata descriptions. How roman numerals are built is not difficult to understand. What´s more difficult, though, might be to find an efficient solution to convert into them automatically. 2. Solve The usual TDD demonstration skips a solution finding phase. Like the interface exploration it´s mixed in with the implementation. But I don´t think this is how it should be done. I even think this is not how it really works for the people demonstrating TDD. They´re simplifying their true software development process because they want to show a streamlined TDD process. I doubt this is helping anybody. Before you code you better have a plan what to code. This does not mean you have to do “Big Design Up-Front”. It just means: Have a clear picture of the logical solution in your head before you start to build a physical solution (code). Evidently such a solution can only be as good as your understanding of the problem. If that´s limited your solution will be limited, too. Fortunately, in the case of this kata your understanding does not need to be limited. Thus the logical solution does not need to be limited or preliminary or tentative. That does not mean you need to know every line of code in advance. It just means you know the rough structure of your implementation beforehand. Because it should mirror the process described by the logical or conceptual solution. Here´s my solution approach: The arabic “encoding” of numbers represents them as an ordered set of powers of 10. Each digit is a factor to multiply a power of ten with. The “encoding” 123 is the short form for a set like this: {1*10^2, 2*10^1, 3*10^0}. And the number is the sum of the set members. The roman “encoding” is different. There is no base (like 10 for arabic numbers), there are just digits of different value, and they have to be written in descending order. The “encoding” XVI is short for [10, 5, 1]. And the number is still the sum of the members of this list. The roman “encoding” thus is simpler than the arabic. Each “digit” can be taken at face value. No multiplication with a base required. But what about IV which looks like a contradiction to the above rule? It is not – if you accept roman “digits” not to be limited to be single characters only. Usually I, V, X, L, C, D, M are viewed as “digits”, and IV, IX etc. are viewed as nuisances preventing a simple solution. All looks different, though, once IV, IX etc. are taken as “digits”. Then MCMLIV is just a sum: M+CM+L+IV which is 1000+900+50+4. Whereas before it would have been understood as M-C+M+L-I+V – which is more difficult because here some “digits” get subtracted. Here´s the list of roman “digits” with their values: {1, I}, {4, IV}, {5, V}, {9, IX}, {10, X}, {40, XL}, {50, L}, {90, XC}, {100, C}, {400, CD}, {500, D}, {900, CM}, {1000, M} Since I take IV, IX etc. as “digits” translating an arabic number becomes trivial. I just need to find the values of the roman “digits” making up the number, e.g. 1954 is made up of 1000, 900, 50, and 4. I call those “digits” factors. If I move from the highest factor (M=1000) to the lowest (I=1) then translation is a two phase process: Find all the factors Translate the factors found Compile the roman representation Translation is just a look-up. Finding, though, needs some calculation: Find the highest remaining factor fitting in the value Remember and subtract it from the value Repeat with remaining value and remaining factors Please note: This is just an algorithm. It´s not code, even though it might be close. Being so close to code in my solution approach is due to the triviality of the problem. In more realistic examples the conceptual solution would be on a higher level of abstraction. With this solution in hand I finally can do what TDD advocates: find and prioritize test cases. As I can see from the small process description above, there are two aspects to test: Test the translation Test the compilation Test finding the factors Testing the translation primarily means to check if the map of factors and digits is comprehensive. That´s simple, even though it might be tedious. Testing the compilation is trivial. Testing factor finding, though, is a tad more complicated. I can think of several steps: First check, if an arabic number equal to a factor is processed correctly (e.g. 1000=M). Then check if an arabic number consisting of two consecutive factors (e.g. 1900=[M,CM]) is processed correctly. Then check, if a number consisting of the same factor twice is processed correctly (e.g. 2000=[M,M]). Finally check, if an arabic number consisting of non-consecutive factors (e.g. 1400=[M,CD]) is processed correctly. I feel I can start an implementation now. If something becomes more complicated than expected I can slow down and repeat this process. 3. Implement First I write a test for the acceptance test cases. It´s red because there´s no implementation even of the API. That´s in conformance with “TDD lore”, I´d say: Next I implement the API: The acceptance test now is formally correct, but still red of course. This will not change even now that I zoom in. Because my goal is not to most quickly satisfy these tests, but to implement my solution in a stepwise manner. That I do by “faking” it: I just “assume” three functions to represent the transformation process of my solution: My hypothesis is that those three functions in conjunction produce correct results on the API-level. I just have to implement them correctly. That´s what I´m trying now – one by one. I start with a simple “detail function”: Translate(). And I start with all the test cases in the obvious equivalence partition: As you can see I dare to test a private method. Yes. That´s a white box test. But as you´ll see it won´t make my tests brittle. It serves a purpose right here and now: it lets me focus on getting one aspect of my solution right. Here´s the implementation to satisfy the test: It´s as simple as possible. Right how TDD wants me to do it: KISS. Now for the second equivalence partition: translating multiple factors. (It´a pattern: if you need to do something repeatedly separate the tests for doing it once and doing it multiple times.) In this partition I just need a single test case, I guess. Stepping up from a single translation to multiple translations is no rocket science: Usually I would have implemented the final code right away. Splitting it in two steps is just for “educational purposes” here. How small your implementation steps are is a matter of your programming competency. Some “see” the final code right away before their mental eye – others need to work their way towards it. Having two tests I find more important. Now for the next low hanging fruit: compilation. It´s even simpler than translation. A single test is enough, I guess. And normally I would not even have bothered to write that one, because the implementation is so simple. I don´t need to test .NET framework functionality. But again: if it serves the educational purpose… Finally the most complicated part of the solution: finding the factors. There are several equivalence partitions. But still I decide to write just a single test, since the structure of the test data is the same for all partitions: Again, I´m faking the implementation first: I focus on just the first test case. No looping yet. Faking lets me stay on a high level of abstraction. I can write down the implementation of the solution without bothering myself with details of how to actually accomplish the feat. That´s left for a drill down with a test of the fake function: There are two main equivalence partitions, I guess: either the first factor is appropriate or some next. The implementation seems easy. Both test cases are green. (Of course this only works on the premise that there´s always a matching factor. Which is the case since the smallest factor is 1.) And the first of the equivalence partitions on the higher level also is satisfied: Great, I can move on. Now for more than a single factor: Interestingly not just one test becomes green now, but all of them. Great! You might say, then I must have done not the simplest thing possible. And I would reply: I don´t care. I did the most obvious thing. But I also find this loop very simple. Even simpler than a recursion of which I had thought briefly during the problem solving phase. And by the way: Also the acceptance tests went green: Mission accomplished. At least functionality wise. Now I´ve to tidy up things a bit. TDD calls for refactoring. Not uch refactoring is needed, because I wrote the code in top-down fashion. I faked it until I made it. I endured red tests on higher levels while lower levels weren´t perfected yet. But this way I saved myself from refactoring tediousness. At the end, though, some refactoring is required. But maybe in a different way than you would expect. That´s why I rather call it “cleanup”. First I remove duplication. There are two places where factors are defined: in Translate() and in Find_factors(). So I factor the map out into a class constant. Which leads to a small conversion in Find_factors(): And now for the big cleanup: I remove all tests of private methods. They are scaffolding tests to me. They only have temporary value. They are brittle. Only acceptance tests need to remain. However, I carry over the single “digit” tests from Translate() to the acceptance test. I find them valuable to keep, since the other acceptance tests only exercise a subset of all roman “digits”. This then is my final test class: And this is the final production code: Test coverage as reported by NCrunch is 100%: Reflexion Is this the smallest possible code base for this kata? Sure not. You´ll find more concise solutions on the internet. But LOC are of relatively little concern – as long as I can understand the code quickly. So called “elegant” code, however, often is not easy to understand. The same goes for KISS code – especially if left unrefactored, as it is often the case. That´s why I progressed from requirements to final code the way I did. I first understood and solved the problem on a conceptual level. Then I implemented it top down according to my design. I also could have implemented it bottom-up, since I knew some bottom of the solution. That´s the leaves of the functional decomposition tree. Where things became fuzzy, since the design did not cover any more details as with Find_factors(), I repeated the process in the small, so to speak: fake some top level, endure red high level tests, while first solving a simpler problem. Using scaffolding tests (to be thrown away at the end) brought two advantages: Encapsulation of the implementation details was not compromised. Naturally private methods could stay private. I did not need to make them internal or public just to be able to test them. I was able to write focused tests for small aspects of the solution. No need to test everything through the solution root, the API. The bottom line thus for me is: Informed TDD produces cleaner code in a systematic way. It conforms to core principles of programming: Single Responsibility Principle and/or Separation of Concerns. Distinct roles in development – being a researcher, being an engineer, being a craftsman – are represented as different phases. First find what, what there is. Then devise a solution. Then code the solution, manifest the solution in code. Writing tests first is a good practice. But it should not be taken dogmatic. And above all it should not be overloaded with purposes. And finally: moving from top to bottom through a design produces refactored code right away. Clean code thus almost is inevitable – and not left to a refactoring step at the end which is skipped often for different reasons.   PS: Yes, I have done this kata several times. But that has only an impact on the time needed for phases 1 and 2. I won´t skip them because of that. And there are no shortcuts during implementation because of that.

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  • Display database content which is last inserted using last inserted ID

    - by user2330772
    What i am doing is i am displaying last inserted data when form data is submitted,the form is multipart/form-data. I am getting this form data using jquery,here i am sending this data to php file using Ajax POST.In that php file i am inserting that data in db table..where i am getting the id of inserted data..on success of Ajax call i am sending that id to another PHP file..where using that id i am displaying the last inserted data... My form is: <form method="post" enctype="multipart/form-data" name="upload_form" id="data"> <select id="sel"> <option>Select the Project Stream</option> <option value="1">Computer Science</option> <option value="2">Mechanical</option> <option value="3">IT</option> <option value="4">Web Development</option> <option value="5">MCA</option> <option value="6">Civil</option> </select><br /> <input type="text" id="title" placeholder="Project Title"/><br /> <input type="text" id="vurl" placeholder="If You have any video about project write your video url path here" style="width:435px;"/><br /> <textarea id="prjdesc" name="prjdesc" rows="20" cols="80" style="border-style:groove;box-shadow: 10px 10px 10px 10px #888888;"placeholder="Please describe Your Project"></textarea> <label for="file">Filename:</label> <input type="file" name="file" id="file"/><br /> <button>Submit</button> </form> My js file: $("form#data").submit(function() { alert("update"); var sid=$("#sel").val(); alert(sid); var ttle = $("#title").val(); alert(ttle); var text = $("#prjdesc").val(); var vurl = $("#vurl").val(); /*var dataString = 'param='+text+'&param1='+vurl+'&param2='+ttle+'&param3='+id;*/ var formData = new FormData($(this)[0]); formData.append('param',text); formData.append('param1',vurl); formData.append('param2',ttle ); formData.append('param3',sid ); $.ajax({ type:'POST', data:formData, url:'insert.php', success:function(id) { alert(id); window.location ="another.php?id="+id; }, cache: false, contentType: false, processData: false }); return false; }); insert.php: <?php print_r($_FILES); $desc = $_POST['param']; echo $desc; $video = $_POST['param1']; echo $video ; $title = $_POST['param2']; echo $title; $tech_id=$_POST['param3']; echo $tech_id; $host="localhost"; $username="root"; $password=""; $db_name="geny"; $tbl_name="project_details"; mysql_connect("$host", "$username", "$password")or die("cannot connect"); mysql_select_db("$db_name")or die("cannot select DB"); $allowedExts = array("gif", "jpeg", "jpg", "png"); $extension = end(explode(".", $_FILES["file"]["name"])); $url_dir = "C:/wamp/www/WebsiteTemplate4/upload/"; if ((($_FILES["file"]["type"] == "image/gif") || ($_FILES["file"]["type"] == "image/jpeg") || ($_FILES["file"]["type"] == "image/jpg") || ($_FILES["file"]["type"] == "image/pjpeg") || ($_FILES["file"]["type"] == "image/x-png") || ($_FILES["file"]["type"] == "image/png")) && ($_FILES["file"]["size"] < 50000) && in_array($extension, $allowedExts)) { if ($_FILES["file"]["error"] > 0) { echo "Return Code: " . $_FILES["file"]["error"] . "<br>"; } else { if (file_exists($url_dir . $_FILES["file"]["name"])) { echo $_FILES["file"]["name"] . " already exists. "; } else { move_uploaded_file($_FILES["file"]["tmp_name"],$url_dir. $_FILES["file"]["name"]); // echo "Stored in: " . "upload/" . $_FILES["file"]["name"]; $tmp = "C:/wamp/www/WebsiteTemplate4/upload/" . $_FILES["file"]["name"]; $sql="INSERT INTO $tbl_name (title, content, img_path, video_url, project_tech_Id) VALUES ('$title','$desc','$tmp','$video','$tech_id')"; if(mysql_query($sql)) { echo mysql_insert_id(); } else { echo "Cannot Insert"; } } } } else { echo "Invalid file"; } ?> another.php: <?php $temp=$_GET['id']; echo $temp; $host="localhost"; $username="root"; $password=""; $db_name="geny"; $tbl_name="project_details"; mysql_connect("$host", "$username", "$password")or die("cannot connect"); mysql_select_db("$db_name")or die("cannot select DB"); $query = mysql_query("SELECT content FROM project_details WHERE id=". $temp); if (!$query) { echo 'Could not run query: ' . mysql_error(); exit; } $row = mysql_fetch_row($query); echo "<div id='uprjct' style='background:#336699;'> <p>$row[0]</p> </div>"; ?> but the ID what i am returning in insert.php containg array of elements...i dont want all these thing i want only ID(which is number).. please tell me what is wrong in my code...

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  • PHP / MYSQL: Database empties when I use a variable in the WHERE condition of the last mysql_query

    - by Christian Cugnet
    <?php require 'connect.php'; $search = $_POST["search"]; These two queries work fine. So I used their format for the one below. $result = mysql_query("SELECT * FROM `subjects` WHERE $search = `student_id`"); $result2 = mysql_query("SELECT * FROM `grades` WHERE $search = `student_id`"); while($row = mysql_fetch_array($result)) { $row2 = mysql_fetch_array($result2); echo"<table border='1'>"; echo "<tr>"; echo "<th>Subjects:</th>"; echo "<th>Current Mark:</th>"; echo "<th>Edit Mark:</th>"; echo"</tr>"; echo"<tr>"; echo "<td>". $row['c1'] ."</td>"; echo "<td>". $row2['m1'] ."</td>"; echo "<td><input type='text' name='m1'></td>"; echo "</tr>"; echo "<tr>"; echo "<td>". $row['c2'] ."</td>"; echo "<td>". $row2['m2'] ."</td>"; echo "<td><input type='text' name='m2'></td>"; echo "</tr>"; echo "<tr>"; echo "<td>". $row['c3'] ."</td>"; echo "<td>". $row2['m3'] ."</td>"; echo "<td><input type='text' name='m3'></td>"; echo "</tr>"; echo "<tr>"; echo "<td>". $row['c4'] ."</td>"; echo "<td>". $row2['m4'] ."</td>"; echo "<td><input type='text' name='m4'></td>"; echo "</tr>"; echo "<tr>"; echo "<td>". $row['c5'] ."</td>"; echo "<td>". $row2['m5'] ."</td>"; echo "<td><input type='text' name='m5'></td>"; echo "</tr>"; echo "<tr>"; echo "<td>". $row['c6'] ."</td>"; echo "<td>". $row2['m6'] ."</td>"; echo "<td><input type='text' name='m6'></td>"; echo "</tr>"; echo "<tr>"; echo "<td>". $row['c7'] ."</td>"; echo "<td>". $row2['m7'] ."</td>"; echo "<td><input type='text' name='m7'></td>"; echo "</tr>"; echo "</table>"; echo "<input type='submit' name='submit' value='Submit'>"; echo "</form>"; } $M1 = $_POST["m1"]; $M2 = $_POST["m2"]; $M3 = $_POST["m3"]; $M4 = $_POST["m4"]; $M5 = $_POST["m5"]; $M6 = $_POST["m6"]; $M7 = $_POST["m7"]; It works if I put numbers e.x. 11111 Otherwise it just enters blank spaces into the table. I've tried '".$search."' I've tried ".$search." mysql_query("UPDATE grades SET m1 = '$M1', m2 = '$M2',m3 = '$M3',m4 = '$M4',m5 = '$M5',m6 = '$M6',m7 = '$M7' WHERE $search = `student_id`"); ?> Table +------------+---+---+---+---+---+---+---+ |student_id|m1|m2|m3|m4|m5|m6|m7| +------------+---+---+---+---+---+---+---+ ===Database d1 == Table structure for table grades |------ |Column|Type|Null|Default |------ |//student_id//|int(5)|No| |m1|text|No| |m2|text|No| |m3|text|No| |m4|text|No| |m5|text|No| |m6|text|No| |m7|text|No| == Dumping data for table grades |11111| | | | | | | |11112|fg|fd|f|f|fd|f|f ===Database d1 == Table structure for table subjects |------ |Column|Type|Null|Default |------ |//student_id//|int(11)|No| |c1|text|No| |c2|text|No| |c3|text|No| |c4|text|No| |c5|text|No| |c6|text|No| |c7|text|No| == Dumping data for table subjects |11111|English|Math|Science|Sport|IT|Art|History |11112|grdgg|vsbvbbb|bdbbrfd|bdbrb|dbrbfbf|fbdfbdbf|dbfbdfb

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