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• CodePlex Daily Summary for Wednesday, July 31, 2013

  CodePlex Daily Summary for Wednesday, July 31, 2013Popular ReleasesSharePoint 2010 Export User Information to Text file, SQL server: Full Source code of the project: Please change SharePoint server address. I have used my sharepoint server -> http://sneakpreviewWINJS CTK (Control Toolkit): Initial Release: Initial release supports the following. Expander NumericBoxXMLPreprocess: 2.0.18: What's new in this release For XML Spreadsheet 2003 format, used the frozen row at the top of the worksheet to indicate the beginning of the values. This prevents you from having to start your values at row 7. This can be overridden with the /firstValueRow (or /vr) argument. Issues Fixed Fix for Issue 13006 : Corrected default treatment of the value "false" Beginning with this version, the FixFalse behavior that has caused confusion to so many, has hopefully been addressed in a way that st...MVVM.EventToCommand: Tommy.MVVM.EventToCommand: Tommy.MVVM.EventToCommand is a free, open source developer focused event2command via WinRT for MVVM Pattern.MVC Generator: MVC Generator Visual Studio Addin: This is the latest build, this includes the MVCGenerator.dll, and Visual Studio Addin file. See the home page of this project for installation instructions.Project Nonnon: 2013_07_30: ----------==========----------==========----------==========---------- "No news is good news." ----------==========----------==========----------==========---------- Change Log 2013/07/30 BUGFIX game/sound/directsound.c n_directsound_loop() OLD : crash when DirectSound is not supported NEW : fixed game/sound/waveout.c when included OLD : compile error NEW : fixed game/chara.c when included OLD : compile error NEW : fixed game/direct2d.c when included ...Dynamics CRM 2011 EasyPlugins: EasyPlugins-1.2.3.1-managed: V1.2.3.1 - Bug Fix : Condition expression is not saved on action creation - Bug Fix : Request Param with single attribute result - Some style changes v1.2.3.0 - Bug Fix : Twice plugins execution. - New Abort action - Depth Plugin Execution management on each action - Turn On/Off EasyPlugins feature (can be useful in some cases of imports) v1.2.0.0 Associate / Disassociate actions are now available Import / Export features Better management of Lookups Trigger NamingXmlObjectMapper: XOM Alpha 1.0: first Alpha Version of XOM: read and write xml nodes and attributes mapping to IList or Interfaces simple property attribute mapping creates new xml nodes at run time IList changes (add, remove) implemented in the next releasenopCommerce. Open source shopping cart (ASP.NET MVC): nopCommerce 3.10: Highlight features & improvements: • Performance optimization. • New more user-friendly product/product-variant logic. Now we'll have only products (simple and grouped). • Bundle products support added. • Allow a store owner to associate product image for product variant attribute values. To see the full list of fixes and changes please visit the release notes page (http://www.nopCommerce.com/releasenotes.aspx).ExtJS based ASP.NET Controls: FineUI v3.3.1: ??FineUI ?? ExtJS ??? ASP.NET ???。 FineUI??? ?? No JavaScript，No CSS，No UpdatePanel，No ViewState，No WebServices ???????。 ?????? IE 7.0、Firefox 3.6、Chrome 3.0、Opera 10.5、Safari 3.0+ ???? Apache License v2.0 ?：ExtJS ?? GPL v3 ?????(http://www.sencha.com/license)。 ???? ??：http://fineui.com/bbs/ ??：http://fineui.com/demo/ ??：http://fineui.com/doc/ ??：http://fineui.codeplex.com/ FineUI ???? ExtJS ????????，???? ExtJS ?，???????????ExtJS?： 1. ????? FineUI ? ExtJS ?：http://fineui.com/bbs/fo...AutoNLayered - Domain Oriented N-Layered .NET 4.5: AutoNLayered v1.0.5: - Fix Dtos. Abstract collections replaced by concrete (correct serialization WCF). - OrderBy in navigation properties. - Unit Test with Fakes. - Map of entities/dto moved to application services. - Libraries updated. Warning using Fakes: http://connect.microsoft.com/VisualStudio/feedback/details/782031/visual-studio-2012-add-fakes-assembly-does-not-add-all-needed-referencesPath Copy Copy: 11.1: Minor release with two new features: Submenu's contextual menu item now has an icon next to it Added reference to JavaScript regular expression format in Settings application Since this release does not have any glaring bug fixes, it is more of an optional update for existing users. It depends on whether you want to be able to spot the Path Copy Copy submenu more easily. I recommend you install it to see if the icon makes sense. As always, please don't hesitate to leave feedback via Discus...CMake Tools for Visual Studio: CMake Tools for Visual Studio 1.0 RC3: This is the third release candidate of CMake Tools for Visual Studio 1.0, which contains the following bug fixes: Opening a CMake file from Windows Explorer while Visual Studio is already open will no start a new instance of Visual Studio. Typing a symbol while the IntelliSense list box is visible and the text typed so far does not match any item in the list will dismiss the list box and insert the symbol typed.R.NET: R.NET 1.5: The major changes in v1.5 are: Initialize method must be called before using R. Settings should be passed to the method. EagerEvaluate method renamed to Evaluate (use Defer method when you want old version of Evaluate).Media Companion: Media Companion MC3.574b: Some good bug fixes been going on with the new XBMC-Link function. Thanks to all who were able to do testing and gave feedback. New:* Added some adhoc extra General movie filters, one of which is Plot = Outline (see fixes above). To see the filters, add the following line to your config.xml: <ShowExtraMovieFilters>True</ShowExtraMovieFilters>. The others are: Imdb in folder name, Imdb in not folder name & Imdb not in folder name & year mismatch. * Movie - display <tag> list on browser tab ...OfflineBrowser: Preview Release with Search: I've added search to this release.VG-Ripper & PG-Ripper: VG-Ripper 2.9.46: changes FIXED LoginMath.NET Numerics: Math.NET Numerics v2.6.0: What's New in Math.NET Numerics 2.6 - Announcement, Explanations and Sample Code. New: Linear Curve Fitting Linear least-squares fitting (regression) to lines, polynomials and linear combinations of arbitrary functions. Multi-dimensional fitting. Also works well in F# with the F# extensions. New: Root Finding Brent's method. ~Candy Chiu, Alexander Täschner Bisection method. ~Scott Stephens, Alexander Täschner Broyden's method, for multi-dimensional functions. ~Alexander Täschner ...AJAX Control Toolkit: July 2013 Release: AJAX Control Toolkit Release Notes - July 2013 Release Version 7.0725July 2013 release of the AJAX Control Toolkit. AJAX Control Toolkit .NET 4.5 – AJAX Control Toolkit for .NET 4.5 and sample site (Recommended). AJAX Control Toolkit .NET 4 – AJAX Control Toolkit for .NET 4 and sample site (Recommended). AJAX Control Toolkit .NET 3.5 – AJAX Control Toolkit for .NET 3.5 and sample site (Recommended). Notes: - Instructions for using the AJAX Control Toolkit with ASP.NET 4.5 can be found at...MJP's DirectX 11 Samples: Specular Antialiasing Sample: Sample code to complement my presentation that's part of the Physically Based Shading in Theory and Practice course at SIGGRAPH 2013, entitled "Crafting a Next-Gen Material Pipeline for The Order: 1886". Demonstrates various methods of preventing aliasing from specular BRDF's when using high-frequency normal maps. The zip file contains source code as well as a pre-compiled x64 binary.New ProjectsA Simple Java Encryption program: This is my very first Java project. It's a file encryptor. It's purpose is to codify a file to make it look like it contain random information.AA??: aa??，????。Browser Chooser 2: Browser Chooser 2 is an updated fork of the original. It's primary goal is to simplify using multiple browser.campuscloud-mobile: Dieses Projekt enthält die mobilen Apps zur Campuscloud App.campuscloud-owncloudplugins: Dieses Projekt enthält die ownCloud-Plugins zu den CampuCloud-Apps, die ownCloud-Server um weitere Funktionalitäten ergänzen.campuscloud-windowsphone8: Diese Projekt enthält die Windows Phone 8 App zur Campuscloud App.Chronos .Net Performance Profiler: Free .Net Performance ProfilerConvertServer: a pet project i works onDevelopment Tools for Solid Edge: Development tools for Solid Edge.DocAssist: The project is to facilitate user's day-to-day management of her files in a customisable way on Windows System equipped with .NET framework.epe: epeETP 3: prueba de asp mvc para desarrollar conjuntamente en un repositorio tfsHello World in MVC4: Application to testInvoke-MsTest PowerShell Module: A PowerShell module that makes unit testing Visual Studio projects fast and easy. Uses MsTest.exe to launch all test associated with your project or solution.MarathonTP: MarathonTP (TP stands for Transport Protocol) is a lightweight communication protocol specificaly developped for machine to machine communication.Multicopter Simulator: A simulation environment for multicopter built with Microsoft Robotics Developer Studio 4.MVC Rags: A bunch of ASP.NET MVC4 helpersMVVM.EventToCommand: Tommy.MVVM.EventToCommand is a free, open source developer focused event2command via WinRT for MVVM Pattern.RNT.Common: rnt.commonStorageOrizer: Software to manage disk space, e.g. move Programs without damaging function. Subset Sum Problem Solver: SubsetThirdPartyLogin: ?????twitterBootstrapAspNetMVCControls: Asp.net MVC Controls based on twiiter Boostrap( a beautiful html & css framework published by Twitter).Unify: Unify is an automatic IoC Container Configurator, based on layers approach via annotations.V32 Assembler: The assembler for my assembly language for my 32-bit virtual machine with a home-made instruction set.

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• CodePlex Daily Summary for Wednesday, November 16, 2011

  CodePlex Daily Summary for Wednesday, November 16, 2011Popular ReleasesMVC Controls Toolkit: Mvc Controls Toolkit 1.5.5: Added: Now the DateRanteAttribute accepts complex expressions containing "Now" and "Today" as static minimum and maximum. Menu, MenuFor helpers capable of handling a "currently selected element". The developer can choose between using a standard nested menu based on a standard SimpleMenuItem class or specifying an item template based on a custom class. Added also helpers to build the tree structure containing all data items the menu takes infos from. Improved the pager. Now the developer ...Public Key Infrastructure PowerShell module: PowerShell PKI Module v0.9.2: Installation guide: Use default installation path to install this module for all users To install this module for current user only — use the following path: %MyDocs%\WindowsPowerShell\Modules Note: you MUST uninstall previously installed module versions. Direct upgrade is not supported! Note: at this time PowerShell 3.0 CTP1 is not supported. Release notes for version 0.9.2: updated and corrected help for several commands. added online help for all commands. Get-CertificationAuthorit...Files Name Copier: 1.0.0.1: Files Name Copier is a simple easy to use utility that allows you to drag and drop any number of files onto it. The clipboard will now contain the list of files you just dropped.SQL Monitor - tracking sql server activities: SQLMon 4.1 alpha 3: 1. improved object search, now show previous/next navigation 2. shows server start up time 3. shows process cpu/ioCODE Framework: 4.0.11115.0: Added support for partial views in the WPF framework, as well as a new helper feature that allows hooking commands/actions to all WPF events.Silverlight Toolkit: Windows Phone Toolkit - Nov 2011 (7.1 SDK): This release is coming soon! What's new ListPicker once again works in a ScrollViewer LongListSelector bug fixes around OutOfRange exceptions, wrong ordering of items, grouping issues, and scrolling events. ItemTuple is now refactored to be the public type LongListSelectorItem to provide users better access to the values in selection changed handlers. PerformanceProgressBar binding fix for IsIndeterminate (item 9767 and others) There is no longer a GestureListener dependency with the C...DotNetNuke® Community Edition: 06.01.01: Major Highlights Fixed problem with the core skin object rendering CSS above the other framework inserted files, which caused problems when using core style skin objects Fixed issue with iFrames getting removed when content is saved Fixed issue with the HTML module removing styling and scripts from the content Fixed issue with inserting the link to jquery after the header of the page Security Fixesnone Updated Modules/Providers ModulesHTML version 6.1.0 ProvidersnoneDotNetNuke Performance Settings: 01.00.00: First release of DotNetNuke SQL update queries to set the DNN installation for optimimal performance. Please review and rate this release... (stars are welcome)SCCM Client Actions Tool: SCCM Client Actions Tool v0.8: SCCM Client Actions Tool v0.8 is currently the latest version. It comes with following changes since last version: Added "Wake On LAN" action. WOL.EXE is now included. Added new action "Get all active advertisements" to list all machine based advertisements on remote computers. Added new action "Get all active user advertisements" to list all user based advertisements for logged on users on remote computers. Added config.ini setting "enablePingTest" to control whether ping test is ru...Windows Azure SDK for PHP: Windows Azure SDK for PHP v4.0.4: INSTALLATION Windows Azure SDK for PHP requires no special installation steps. Simply download the SDK, extract it to the folder you would like to keep it in, and add the library directory to your PHP include_path. INSTALLATION VIA PEAR Maarten Balliauw provides an unofficial PEAR channel via http://www.pearplex.net. Here's how to use it: New installation: pear channel-discover pear.pearplex.net pear install pearplex/PHPAzure Or if you've already installed PHPAzure before: pear upgrade p...QuickGraph, Graph Data Structures And Algorithms for .Net: 3.6.61116.0: Portable library build that allows to use QuickGraph in any .NET environment: .net 4.0, silverlight 4.0, WP7, Win8 Metro apps.Devpad: 4.7: Whats new for Devpad 4.7: New export to Rich Text New export to FlowDocument Minor Bug Fix's, improvements and speed upsDesktop Google Reader: 1.4.2: This release remove the like and the broadcast buttons as Google Reader stopped supporting them (no, we don't like this decission...) Additionally and to have at least a small plus: the login window now automaitcally logs you in if you stored username and passwort (no more extra click needed) Finally added WebKit .NET to the about window and removed Awesomium MD5-Hash: 5fccf25a2fb4fecc1dc77ebabc8d3897 SHA-Hash: d44ff788b123bd33596ad1a75f3b9fa74a862fdbRDRemote: Remote Desktop remote configurator V 1.0.0: Remote Desktop remote configurator V 1.0.0Rawr: Rawr 4.2.7: 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 AddonWe 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 bag and bank items) like Char...VidCoder: 1.2.2: Updated Handbrake core to svn 4344. Fixed the 6-channel discrete mixdown option not appearing for AAC encoders. Added handling for possible exceptions when copying to the clipboard, added retries and message when it fails. Fixed issue with audio bitrate UI not appearing sometimes when switching audio encoders. Added extra checks to protect against reported crashes. Added code to upgrade encoding profiles on old queued items.Media Companion: MC 3.422b Weekly: Ensure .NET 4.0 Full Framework is installed. (Available from http://www.microsoft.com/download/en/details.aspx?id=17718) Ensure the NFO ID fix is applied when transitioning from versions prior to 3.416b. (Details here) TV Show Resolutions... Made the TV Shows folder list sorted. Re-visibled 'Manually Add Path' in Root Folders. Sorted list to process during new tv episode search Rebuild Movies now processes thru folders alphabetically Fix for issue #208 - Display Missing Episodes is not popu...XPath Visualizer: XPathVisualizer v1.3 Latest: This is v1.3.0.6 of XpathVisualizer. This is an update release for v1.3. These workitems have been fixed since v1.3.0.5: 7429 7432 7427MSBuild Extension Pack: November 2011: Release Blog Post The MSBuild Extension Pack November 2011 release provides a collection of over 415 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, GU...Extensions for Reactive Extensions (Rxx): Rxx 1.2: What's NewRelated Work Items Please read the latest release notes for details about what's new. Content SummaryRxx provides the following features. See the Documentation for details. Many IObservable<T> extension methods and IEnumerable<T> extension methods. Many useful types such as ViewModel, CommandSubject, ListSubject, DictionarySubject, ObservableDynamicObject, Either<TLeft, TRight>, Maybe<T> and others. Various interactive labs that illustrate the runtime behavior of the extensio...New Projects#foo MigratorFoo: Migration generator for NHibernate projects with integrated NuGet console commands.Best music production software: Programmers needed to make the perfect open source music production software: I have a well structured creative idea based on the following principle "powerful simplicity"...Bricks: Bricks is a development foundation for different technologyCultiv Jupiter Contact Form: A contact form package for Umbraco v5 (Jupiter)DNN Fan Gate: A simple module for fan gating content in DotNetNukeDobo: DoboDotNetNuke Performance Settings: A set of SQL queries that will change the (Host & Schedule) settings of your DotNetNuke installation for maximal production performance or set it optimal for Development. These queries were used in my presentation on DotNetNuke World 2011.Experiment Manager: This project was developed as a response to the requirements for an experiment manager software for clinical psychology experiments. Feedbook: Feedbook supports any RSS and Atom news feeds, It can also download podcasts saliently and play it within Feedbook. It integrates with Twitter and Google Buzz very well, you can send tweets/post easily and can also subscribe to twitter timelines/buzz feeds. Characters like # & @ also recognize as special keywords, so that you can subscribe to feeds of any on going topic on twitter like #download, #movie or #cricket. http://feedbook.orgFiles Name Copier: Files Name Copier is a simple easy to use utility that allows you to drag and drop any number of files onto it. The clipboard will now contain the list of files you just dropped.Kinban: Kinect + TFS This is a WPF representation of a Kanban board that can be manipulated with the Kinect.MapTeamsPolls: This is an ASP.Net ajax polls user controls. Using ajax and jQuery. This user controls can be used in any ASP.Net 4.0 projects. Use the build script to create Umbraco package for the user controls and the admin page. As a bonus, there is a ruby rake build script for the package.MetroButton with Converter Image SVG2XAML Silverlight: - Control library SL4 with Button Metro Style - Windows application for download and convert SVG to Resource.xaml for silverlightMetroIoc - a simple WinRT IoC container: A WinRT port of the MicroIoc container... MetroIoc is a native WinRT Inversion of Control container, for use in Metro style apps. Check the license for usage rights of this projectMTN Library: .NET library with extensions for LINQ and Entity Framework as well as useful extensions. Contains many extensions, features for display methods using jquery Ajax. Has a proxy to create and use methods with cache as much as in the ajax methods.myDeck: Main goal of this project is to show best practices and patterns for unit testing in Silverlight Technology. It is developed as part of BAThesisNetwork extensions for .net Micro Framework and Gadgeteer: Adds .net Microframework support for - BinaryReader - BinaryWriter Adds a FEZ way for TCP and UDP networking to the Gadgeteer platformNewSunse: this card creating projectOrchard CMS ImageResizer: resize or scale images in orchard simply by url or using the build-in HtmlHelperReportCenter: ReportCenterSharePoint 2010 Extended Lookup Field: This project installs a custom lookup field, which allows the user to choose the item through a SharePoint 2010 popup. Here are the features offered by this field: - high extensibility - high performance when woking with very large lists - small size for new and edit list forms - posibility to specify you own search page - SharePoint 2010 lookup and feel The project is a VS2010 SharePoint 2010 project. Simplicity Framework: Simplicity is a framework to automatic generate dataccess an UI code for crudlstackoverflowstore: Homenaje a stackoverflow.Stoc: Aplicatia Stoc simplifica generarea facturilor si a retelor, gestionand stocul marfii unei firme. Student PAS: Student PAS is a simple webapp for assign tasks for students. It was created with educational purposes. Thus, it is not an serious usable software.System Center 2012 - Operations Manager Managed Module Samples: Sample Visual Studio 2010 projects that illustrate how you can create custom module types for System Center 2012 - Operations Manager. The project contains the C# code for creating data source, write action, probe and condition detection modules and more.Tecnosop: Sistema de facturacion de TecnosopUtilityLibrary.FormControl: FormControlWebRequestFrequencyControl: This project intends to solve the web request frequency control problem. This solution is based on HttpModule and highly configurable. If you need to limit the frequency of requests, you may interest in this.Windows Phone Marketplace Analytics: Libraries (and data) to help you access and analyze the different information provided by the MS marketplace.Windows Troubleshooting Platform Starter Packs: Starter Packs are open source packages based on the Windows Troubleshooting Platform that can be modified by developers to suit their specific needs. Starter Packs are an easy way for developers to create and distribute a Windows Troubleshooting Pack to diagnose computer problems.

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• EM12c: Using the LIST verb in emcli

  - by SubinDaniVarughese

  Many of us who use EM CLI to write scripts and automate our daily tasks should not miss out on the new list verb released with Oracle Enterprise Manager 12.1.0.3.0. The combination of list and Jython based scripting support in EM CLI makes it easier to achieve automation for complex tasks with just a few lines of code. Before I jump into a script, let me highlight the key attributes of the list verb and why it’s simply excellent! 1. Multiple resources under a single verb:A resource can be set of users or targets, etc. Using the list verb, you can retrieve information about a resource from the repository database.Here is an example which retrieves the list of administrators within EM.Standard mode$ emcli list -resource="Administrators" Interactive modeemcli>list(resource="Administrators")The output will be the same as standard mode.Standard mode$ emcli @myAdmin.pyEnter password :  ******The output will be the same as standard mode.Contents of myAdmin.py scriptlogin()print list(resource="Administrators",jsonout=False).out()To get a list of all available resources use$ emcli list -helpWith every release of EM, more resources are being added to the list verb. If you have a resource which you feel would be valuable then go ahead and contact Oracle Support to log an enhancement request with product development. Be sure to say how the resource is going to help improve your daily tasks. 2. Consistent Formatting:It is possible to format the output of any resource consistently using these options:  –column  This option is used to specify which columns should be shown in the output. Here is an example which shows the list of administrators and their account status$ emcli list -resource="Administrators" -columns="USER_NAME,REPOS_ACCOUNT_STATUS" To get a list of columns in a resource use:$ emcli list -resource="Administrators" -help You can also specify the width of the each column. For example, here the column width of user_type is set to 20 and department to 30. $ emcli list -resource=Administrators -columns="USER_NAME,USER_TYPE:20,COST_CENTER,CONTACT,DEPARTMENT:30"This is useful if your terminal is too small or you need to fine tune a list of specific columns for your quick use or improved readability.  –colsize  This option is used to resize column widths.Here is the same example as above, but using -colsize to define the width of user_type to 20 and department to 30.$ emcli list -resource=Administrators -columns="USER_NAME,USER_TYPE,COST_CENTER,CONTACT,DEPARTMENT" -colsize="USER_TYPE:20,DEPARTMENT:30" The existing standard EMCLI formatting options are also available in list verb. They are: -format="name:pretty" | -format="name:script” | -format="name:csv" | -noheader | -scriptThere are so many uses depending on your needs. Have a look at the resources and columns in each resource. Refer to the EMCLI book in EM documentation for more information.3. Search:Using the -search option in the list verb makes it is possible to search for a specific row in a specific column within a resource. This is similar to the sqlplus where clause. The following operators are supported:           =           !=           >           <           >=           <=           like           is (Must be followed by null or not null)Here is an example which searches for all EM administrators in the marketing department located in the USA.$emcli list -resource="Administrators" -search="DEPARTMENT ='Marketing'" -search="LOCATION='USA'" Here is another example which shows all the named credentials created since a specific date.  $emcli list -resource=NamedCredentials -search="CredCreatedDate > '11-Nov-2013 12:37:20 PM'"Note that the timestamp has to be in the format DD-MON-YYYY HH:MI:SS AM/PM Some resources need a bind variable to be passed to get output. A bind variable is created in the resource and then referenced in the command. For example, this command will list all the default preferred credentials for target type oracle_database.Here is an example$ emcli list -resource="PreferredCredentialsDefault" -bind="TargetType='oracle_database'" -colsize="SetName:15,TargetType:15" You can provide multiple bind variables. To verify if a column is searchable or requires a bind variable, use the –help option. Here is an example:$ emcli list -resource="PreferredCredentialsDefault" -help 4. Secure accessWhen list verb collects the data, it only displays content for which the administrator currently logged into emcli, has access. For example consider this usecase:AdminA has access only to TargetA. AdminA logs into EM CLIExecuting the list verb to get the list of all targets will only show TargetA.5. User defined SQLUsing the –sql option, user defined sql can be executed. The SQL provided in the -sql option is executed as the EM user MGMT_VIEW, which has read-only access to the EM published MGMT$ database views in the SYSMAN schema. To get the list of EM published MGMT$ database views, go to the Extensibility Programmer's Reference book in EM documentation. There is a chapter about Using Management Repository Views. It’s always recommended to reference the documentation for the supported MGMT$ database views.  Consider you are using the MGMT$ABC view which is not in the chapter. During upgrade, it is possible, since the view was not in the book and not supported, it is likely the view might undergo a change in its structure or the data in it. Using a supported view ensures that your scripts using -sql will continue working after upgrade.Here’s an example  $ emcli list -sql='select * from mgmt$target' 6. JSON output support    JSON (JavaScript Object Notation) enables data to be displayed in a collection of name/value pairs. There is lot of reading material about JSON on line for more information.As an example, we had a requirement where an EM administrator had many 11.2 databases in their test environment and the developers had requested an Administrator to change the lifecycle status from Test to Production which meant the admin had to go to the EM “All targets” page and identify the set of 11.2 databases and then to go into each target database page and manually changes the property to Production. Sounds easy to say, but this Administrator had numerous targets and this task is repeated for every release cycle.We told him there is an easier way to do this with a script and he can reuse the script whenever anyone wanted to change a set of targets to a different Lifecycle status. Here is a jython script which uses list and JSON to change all 11.2 database target’s LifeCycle Property value.If you are new to scripting and Jython, I would suggest visiting the basic chapters in any Jython tutorials. Understanding Jython is important to write the logic depending on your usecase.If you are already writing scripts like perl or shell or know a programming language like java, then you can easily understand the logic.Disclaimer: The scripts in this post are subject to the Oracle Terms of Use located here.  1 from emcli import *  2  search_list = ['PROPERTY_NAME=\'DBVersion\'','TARGET_TYPE= \'oracle_database\'','PROPERTY_VALUE LIKE \'11.2%\'']  3 if len(sys.argv) == 2:  4    print login(username=sys.argv[0])  5    l_prop_val_to_set = sys.argv[1]  6      l_targets = list(resource="TargetProperties", search=search_list,   columns="TARGET_NAME,TARGET_TYPE,PROPERTY_NAME")  7    for target in l_targets.out()['data']:  8       t_pn = 'LifeCycle Status'  9      print "INFO: Setting Property name " + t_pn + " to value " +       l_prop_val_to_set + " for " + target['TARGET_NAME']  10      print  set_target_property_value(property_records=      target['TARGET_NAME']+":"+target['TARGET_TYPE']+":"+      t_pn+":"+l_prop_val_to_set)  11  else:  12   print "\n ERROR: Property value argument is missing"  13   print "\n INFO: Format to run this file is filename.py <username>   <Database Target LifeCycle Status Property Value>" You can download the script from here. I could not upload the file with .py extension so you need to rename the file to myScript.py before executing it using emcli.A line by line explanation for beginners: Line  1 Imports the emcli verbs as functions  2 search_list is a variable to pass to the search option in list verb. I am using escape character for the single quotes. In list verb to pass more than one value for the same option, you should define as above comma separated values, surrounded by square brackets.  3 This is an “if” condition to ensure the user does provide two arguments with the script, else in line #15, it prints an error message.  4 Logging into EM. You can remove this if you have setup emcli with autologin. For more details about setup and autologin, please go the EM CLI book in EM documentation.  5 l_prop_val_to_set is another variable. This is the property value to be set. Remember we are changing the value from Test to Production. The benefit of this variable is you can reuse the script to change the property value from and to any other values.  6 Here the output of the list verb is stored in l_targets. In the list verb I am passing the resource as TargetProperties, search as the search_list variable and I only need these three columns – target_name, target_type and property_name. I don’t need the other columns for my task.  7 This is a for loop. The data in l_targets is available in JSON format. Using the for loop, each pair will now be available in the ‘target’ variable.  8 t_pn is the “LifeCycle Status” variable. If required, I can have this also as an input and then use my script to change any target property. In this example, I just wanted to change the “LifeCycle Status”.  9 This a message informing the user the script is setting the property value for dbxyz.  10 This line shows the set_target_property_value verb which sets the value using the property_records option. Once it is set for a target pair, it moves to the next one. In my example, I am just showing three dbs, but the real use is when you have 20 or 50 targets. The script is executed as:$ emcli @myScript.py subin Production The recommendation is to first test the scripts before running it on a production system. We tested on a small set of targets and optimizing the script for fewer lines of code and better messaging.For your quick reference, the resources available in Enterprise Manager 12.1.0.4.0 with list verb are:$ emcli list -helpWatch this space for more blog posts using the list verb and EM CLI Scripting use cases. I hope you enjoyed reading this blog post and it has helped you gain more information about the list verb. Happy Scripting!!Disclaimer: The scripts in this post are subject to the Oracle Terms of Use located here. Stay Connected: Twitter | Facebook | YouTube | Linkedin | Newsletter mt=8">Download the Oracle Enterprise Manager 12c Mobile app

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• Using CSS3 media queries in HTML 5 pages

  - by nikolaosk

  This is going to be the seventh post in a series of posts regarding HTML 5. You can find the other posts here , here , here, here , here and here. In this post I will provide a hands-on example on how to use CSS 3 Media Queries in HTML 5 pages. This is a very important feature since nowadays lots of users view websites through their mobile devices. Web designers were able to define media-specific style sheets for quite a while, but have been limited to the type of output. The output could only be Screen, Print .The way we used to do things before CSS 3 was to have separate CSS files and the browser decided which style sheet to use. Please have a look at the snippet below - HTML 4 media queries <link rel="stylesheet" type="text/css" media="screen" href="styles.css"> <link rel="stylesheet" type="text/css" media="print" href="print-styles.css"> ?he browser determines which style to use. With CSS 3 we can have all media queries in one stylesheet. Media queries can determine the resolution of the device, the orientation of the device, the width and height of the device and the width and height of the browser window.We can also include CSS 3 media queries in separate stylesheets. In order to be absolutely clear this is not (and could not be) a detailed tutorial on HTML 5. There are other great resources for that.Navigate to the excellent interactive tutorials of W3School. Another excellent resource is HTML 5 Doctor. Two very nice sites that show you what features and specifications are implemented by various browsers and their versions are http://caniuse.com/ and http://html5test.com/. At this times Chrome seems to support most of HTML 5 specifications.Another excellent way to find out if the browser supports HTML 5 and CSS 3 features is to use the Javascript lightweight library Modernizr. In this hands-on example I will be using Expression Web 4.0.This application is not a free application. You can use any HTML editor you like.You can use Visual Studio 2012 Express edition. You can download it here. Before I go on with the actual demo I will use the (http://www.caniuse.com) to see the support for CSS 3 Media Queries from the latest versions of modern browsers. Please have a look at the picture below. We see that all the latest versions of modern browsers support this feature. We can see that even IE 9 supports this feature.   Let's move on with the actual demo.  This is going to be a rather simple demo.I create a simple HTML 5 page. The markup follows and it is very easy to use and understand.This is a page with a 2 column layout. <!DOCTYPE html><html lang="en">  <head>    <title>HTML 5, CSS3 and JQuery</title>    <meta http-equiv="Content-Type" content="text/html;charset=utf-8" >    <link rel="stylesheet" type="text/css" href="style.css">       </head>  <body>    <div id="header">      <h1>Learn cutting edge technologies</h1>      <p>HTML 5, JQuery, CSS3</p>    </div>    <div id="main">      <div id="mainnews">        <div>          <h2>HTML 5</h2>        </div>        <div>          <p>            HTML5 is the latest version of HTML and XHTML. The HTML standard defines a single language that can be written in HTML and XML. It attempts to solve issues found in previous iterations of HTML and addresses the needs of Web Applications, an area previously not adequately covered by HTML.          </p>          <div class="quote">            <h4>Do More with Less</h4>            <p>             jQuery is a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development.             </p>            </div>          <p>            The HTML5 test(html5test.com) score is an indication of how well your browser supports the upcoming HTML5 standard and related specifications. Even though the specification isn't finalized yet, all major browser manufacturers are making sure their browser is ready for the future. Find out which parts of HTML5 are already supported by your browser today and compare the results with other browsers.                      The HTML5 test does not try to test all of the new features offered by HTML5, nor does it try to test the functionality of each feature it does detect. Despite these shortcomings we hope that by quantifying the level of support users and web developers will get an idea of how hard the browser manufacturers work on improving their browsers and the web as a development platform.</p>        </div>      </div>              <div id="CSS">        <div>          <h2>CSS 3 Intro</h2>        </div>        <div>          <p>          Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation semantics (the look and formatting) of a document written in a markup language. Its most common application is to style web pages written in HTML and XHTML, but the language can also be applied to any kind of XML document, including plain XML, SVG and XUL.          </p>        </div>      </div>            <div id="CSSmore">        <div>          <h2>CSS 3 Purpose</h2>        </div>        <div>          <p>            CSS is designed primarily to enable the separation of document content (written in HTML or a similar markup language) from document presentation, including elements such as the layout, colors, and fonts.[1] This separation can improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, enable multiple pages to share formatting, and reduce complexity and repetition in the structural content (such as by allowing for tableless web design).          </p>        </div>      </div>                </div>    <div id="footer">        <p>Feel free to google more about the subject</p>      </div>     </body>  </html>    The CSS code (style.css) follows  body{        line-height: 30px;        width: 1024px;        background-color:#eee;      }            p{        font-size:17px;    font-family:"Comic Sans MS"      }      p,h2,h3,h4{        margin: 0 0 20px 0;      }            #main, #header, #footer{        width: 100%;        margin: 0px auto;        display:block;      }            #header{        text-align: center;         border-bottom: 1px solid #000;         margin-bottom: 30px;      }            #footer{        text-align: center;         border-top: 1px solid #000;         margin-bottom: 30px;      }            .quote{        width: 200px;       margin-left: 10px;       padding: 5px;       float: right;       border: 2px solid #000;       background-color:#F9ACAE;      }            .quote :last-child{        margin-bottom: 0;      }            #main{        column-count:2;        column-gap:20px;        column-rule: 1px solid #000;        -moz-column-count: 2;        -webkit-column-count: 2;        -moz-column-gap: 20px;        -webkit-column-gap: 20px;        -moz-column-rule: 1px solid #000;        -webkit-column-rule: 1px solid #000;      } Now I view the page in the browser.Now I am going to write a media query and add some more rules in the .css file in order to change the layout of the page when the page is viewed by mobile devices. @media only screen and (max-width: 480px) {          body{            width: 480px;          }          #main{            -moz-column-count: 1;            -webkit-column-count: 1;          }        }   I am specifying that this media query applies only to screen and a max width of 480 px. If this condition is true, then I add new rules for the body element. I change the number of columns to one. This rule will not be applied unless the maximum width is 480px or less.  As I decrease the size-width of the browser window I see no change in the column's layout. Have a look at the picture below. When I resize the window and the width of the browser so the width is less than 480px, the media query and its respective rules take effect.We can scroll vertically to view the content which is a more optimised viewing experience for mobile devices. Have a look at the picture below Hope it helps!!!!

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• CBO????????

  - by Liu Maclean(???)

  ???Itpub????????CBO??????????, ????????: SQL> create table maclean1 as select * from dba_objects; Table created. SQL> update maclean1 set status='INVALID' where owner='MACLEAN'; 2 rows updated. SQL> commit; Commit complete. SQL> create index ind_maclean1 on maclean1(status); Index created. SQL> exec dbms_stats.gather_table_stats('SYS','MACLEAN1',cascade=>true); PL/SQL procedure successfully completed. SQL> explain plan for select * from maclean1 where status='INVALID'; Explained. SQL> set linesize 140 pagesize 1400 SQL> select * from table(dbms_xplan.display()); PLAN_TABLE_OUTPUT --------------------------------------------------------------------------- Plan hash value: 987568083 ------------------------------------------------------------------------------ | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ------------------------------------------------------------------------------ | 0 | SELECT STATEMENT | | 11320 | 1028K| 85 (0)| 00:00:02 | |* 1 | TABLE ACCESS FULL| MACLEAN1 | 11320 | 1028K| 85 (0)| 00:00:02 | ------------------------------------------------------------------------------ Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter("STATUS"='INVALID') 13 rows selected. 10053 trace Access path analysis for MACLEAN1 *************************************** SINGLE TABLE ACCESS PATH   Single Table Cardinality Estimation for MACLEAN1[MACLEAN1]   Column (#10): STATUS(     AvgLen: 7 NDV: 2 Nulls: 0 Density: 0.500000   Table: MACLEAN1  Alias: MACLEAN1     Card: Original: 22639.000000  Rounded: 11320  Computed: 11319.50  Non Adjusted: 11319.50   Access Path: TableScan     Cost:  85.33  Resp: 85.33  Degree: 0       Cost_io: 85.00  Cost_cpu: 11935345       Resp_io: 85.00  Resp_cpu: 11935345   Access Path: index (AllEqRange)     Index: IND_MACLEAN1     resc_io: 185.00  resc_cpu: 8449916     ix_sel: 0.500000  ix_sel_with_filters: 0.500000     Cost: 185.24  Resp: 185.24  Degree: 1   Best:: AccessPath: TableScan          Cost: 85.33  Degree: 1  Resp: 85.33  Card: 11319.50  Bytes: 0 ?????10053????????????,?????Density = 0.5 ?? 1/ NDV ??? ??????????????STATUS='INVALID"???????????, ????????????????? ????”STATUS”=’INVALID’ condition???2?,?status??????,??????dbms_stats?????????????,???CBO????INDEX Range ind_maclean1,???????,??????opitimizer?????? ?????????????????????????,????????,??????????status=’INVALID’???????card??,????????: [oracle@vrh4 ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.2.0 Production on Mon Oct 17 19:15:45 2011 Copyright (c) 1982, 2010, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> select * from v$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production PL/SQL Release 11.2.0.2.0 - Production CORE 11.2.0.2.0 Production TNS for Linux: Version 11.2.0.2.0 - Production NLSRTL Version 11.2.0.2.0 - Production SQL> show parameter optimizer_fea NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ optimizer_features_enable string 11.2.0.2 SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com & www.askmaclean.com SQL> drop table maclean; Table dropped. SQL> create table maclean as select * from dba_objects; Table created. SQL> update maclean set status='INVALID' where owner='MACLEAN'; 2 rows updated. SQL> commit; Commit complete. SQL> create index ind_maclean on maclean(status); Index created. SQL> exec dbms_stats.gather_table_stats('SYS','MACLEAN',cascade=>true, method_opt=>'FOR ALL COLUMNS SIZE 2'); PL/SQL procedure successfully completed. ???????2?bucket????, ??????????????? ???Quest???Guy Harrison???????FREQUENCY????????,??????: rem rem Generate a histogram of data distribution in a column as recorded rem in dba_tab_histograms rem rem Guy Harrison Jan 2010 : www.guyharrison.net rem rem hexstr function is from From http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:707586567563 set pagesize 10000 set lines 120 set verify off col char_value format a10 heading "Endpoint|value" col bucket_count format 99,999,999 heading "bucket|count" col pct format 999.99 heading "Pct" col pct_of_max format a62 heading "Pct of|Max value" rem col endpoint_value format 9999999999999 heading "endpoint|value" CREATE OR REPLACE FUNCTION hexstr (p_number IN NUMBER) RETURN VARCHAR2 AS l_str LONG := TO_CHAR (p_number, 'fm' || RPAD ('x', 50, 'x')); l_return VARCHAR2 (4000); BEGIN WHILE (l_str IS NOT NULL) LOOP l_return := l_return || CHR (TO_NUMBER (SUBSTR (l_str, 1, 2), 'xx')); l_str := SUBSTR (l_str, 3); END LOOP; RETURN (SUBSTR (l_return, 1, 6)); END; / WITH hist_data AS ( SELECT endpoint_value,endpoint_actual_value, NVL(LAG (endpoint_value) OVER (ORDER BY endpoint_value),' ') prev_value, endpoint_number, endpoint_number, endpoint_number - NVL (LAG (endpoint_number) OVER (ORDER BY endpoint_value), 0) bucket_count FROM dba_tab_histograms JOIN dba_tab_col_statistics USING (owner, table_name,column_name) WHERE owner = '&owner' AND table_name = '&table' AND column_name = '&column' AND histogram='FREQUENCY') SELECT nvl(endpoint_actual_value,endpoint_value) endpoint_value , bucket_count, ROUND(bucket_count*100/SUM(bucket_count) OVER(),2) PCT, RPAD(' ',ROUND(bucket_count*50/MAX(bucket_count) OVER()),'*') pct_of_max FROM hist_data; WITH hist_data AS ( SELECT endpoint_value,endpoint_actual_value, NVL(LAG (endpoint_value) OVER (ORDER BY endpoint_value),' ') prev_value, endpoint_number, endpoint_number, endpoint_number - NVL (LAG (endpoint_number) OVER (ORDER BY endpoint_value), 0) bucket_count FROM dba_tab_histograms JOIN dba_tab_col_statistics USING (owner, table_name,column_name) WHERE owner = '&owner' AND table_name = '&table' AND column_name = '&column' AND histogram='FREQUENCY') SELECT hexstr(endpoint_value) char_value, bucket_count, ROUND(bucket_count*100/SUM(bucket_count) OVER(),2) PCT, RPAD(' ',ROUND(bucket_count*50/MAX(bucket_count) OVER()),'*') pct_of_max FROM hist_data ORDER BY endpoint_value; ?????,??????????FREQUENCY?????: ??dbms_stats ?????STATUS=’INVALID’ bucket count=9 percent = 0.04 ,??????10053 trace????????: SQL> explain plan for select * from maclean where status='INVALID'; Explained. SQL>  select * from table(dbms_xplan.display()); PLAN_TABLE_OUTPUT ------------------------------------- Plan hash value: 3087014066 ------------------------------------------------------------------------------------------- | Id  | Operation                   | Name        | Rows  | Bytes | Cost (%CPU)| Time     | ------------------------------------------------------------------------------------------- |   0 | SELECT STATEMENT            |             |     9 |   837 |     2   (0)| 00:00:01 | |   1 |  TABLE ACCESS BY INDEX ROWID| MACLEAN     |     9 |   837 |     2   (0)| 00:00:01 | |*  2 |   INDEX RANGE SCAN          | IND_MACLEAN |     9 |       |     1   (0)| 00:00:01 | ------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): ---------------------------------------------------    2 - access("STATUS"='INVALID') ??????????????CBO???????STATUS=’INVALID’?cardnality?? , ??????????? ,??index range scan??Full table scan? ????????????????10053 trace: SQL> alter system flush shared_pool; System altered. SQL> oradebug setmypid; Statement processed. SQL> oradebug event 10053 trace name context forever ,level 1; Statement processed. SQL> explain plan for select * from maclean where status='INVALID'; Explained. SINGLE TABLE ACCESS PATH Single Table Cardinality Estimation for MACLEAN[MACLEAN] Column (#10): NewDensity:0.000199, OldDensity:0.000022 BktCnt:22640, PopBktCnt:22640, PopValCnt:2, NDV:2 ???NewDensity= bucket_count / SUM(bucket_count) /2 Column (#10): STATUS( AvgLen: 7 NDV: 2 Nulls: 0 Density: 0.000199 Histogram: Freq #Bkts: 2 UncompBkts: 22640 EndPtVals: 2 Table: MACLEAN Alias: MACLEAN Card: Original: 22640.000000 Rounded: 9 Computed: 9.00 Non Adjusted: 9.00 Access Path: TableScan Cost: 85.30 Resp: 85.30 Degree: 0 Cost_io: 85.00 Cost_cpu: 10804625 Resp_io: 85.00 Resp_cpu: 10804625 Access Path: index (AllEqRange) Index: IND_MACLEAN resc_io: 2.00 resc_cpu: 20763 ix_sel: 0.000398 ix_sel_with_filters: 0.000398 Cost: 2.00 Resp: 2.00 Degree: 1 Best:: AccessPath: IndexRange Index: IND_MACLEAN Cost: 2.00 Degree: 1 Resp: 2.00 Card: 9.00 Bytes: 0 ???????????2 bucket?????CBO????????????,???????????????????,???dbms_stats.DEFAULT_METHOD_OPT????????????????????? ???dbms_stats?????????????????????col_usage$??????predicate???????,??col_usage$??<????????SMON??(?):??col_usage$????>? ??????????dbms_stats????????,col_usage$????????????predicate???,??dbms_stats??????????????????, ?: SQL> drop table maclean; Table dropped. SQL> create table maclean as select * from dba_objects; Table created. SQL> update maclean set status='INVALID' where owner='MACLEAN'; 2 rows updated. SQL> commit; Commit complete. SQL> create index ind_maclean on maclean(status); Index created. ??dbms_stats??method_opt??maclean? SQL> exec dbms_stats.gather_table_stats('SYS','MACLEAN'); PL/SQL procedure successfully completed. @histogram.sql Enter value for owner: SYS old  12:    WHERE owner = '&owner' new  12:    WHERE owner = 'SYS' Enter value for table: MACLEAN old  13:      AND table_name = '&table' new  13:      AND table_name = 'MACLEAN' Enter value for column: STATUS old  14:      AND column_name = '&column' new  14:      AND column_name = 'STATUS' no rows selected ????col_usage$?????,????????status????? declare begin for i in 1..500 loop execute immediate ' alter system flush shared_pool'; DBMS_STATS.FLUSH_DATABASE_MONITORING_INFO; execute immediate 'select count(*) from maclean where status=''INVALID'' ' ; end loop; end; / PL/SQL procedure successfully completed. SQL> select obj# from obj$ where name='MACLEAN';       OBJ# ----------      97215 SQL> select * from  col_usage$ where  OBJ#=97215;       OBJ#    INTCOL# EQUALITY_PREDS EQUIJOIN_PREDS NONEQUIJOIN_PREDS RANGE_PREDS LIKE_PREDS NULL_PREDS TIMESTAMP ---------- ---------- -------------- -------------- ----------------- ----------- ---------- ---------- ---------      97215          1              1              0                 0           0          0          0 17-OCT-11      97215         10            499              0                 0           0          0          0 17-OCT-11 SQL> exec dbms_stats.gather_table_stats('SYS','MACLEAN'); PL/SQL procedure successfully completed. @histogram.sql Enter value for owner: SYS Enter value for table: MACLEAN Enter value for column: STATUS Endpoint        bucket         Pct of value            count     Pct Max value ---------- ----------- ------- -------------------------------------------------------------- INVALI               2     .04 VALIC3           5,453   99.96  *************************************************

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• CodePlex Daily Summary for Saturday, October 29, 2011

  CodePlex Daily Summary for Saturday, October 29, 2011Popular Releasespatterns & practices: Enterprise Library Contrib: Enterprise Library Contrib - 5.0 (Oct 2011): This release of Enterprise Library Contrib is based on the Microsoft patterns & practices Enterprise Library 5.0 core and contains the following: Common extensionsTypeConfigurationElement<T> - A Polymorphic Configuration Element without having to be part of a PolymorphicConfigurationElementCollection. AnonymousConfigurationElement - A Configuration element that can be uniquely identified without having to define its name explicitly. Data Access Application Block extensionsMySql Provider - ...Network Monitor Open Source Parsers: Network Monitor Parsers 3.4.2748: The Network Monitor Parsers packages contain parsers for more than 400 network protocols, including RFC based public protocols and protocols for Microsoft products defined in the Microsoft Open Specifications for Windows and SQL Server. NetworkMonitor_Parsers.msi is the base parser package which defines parsers for commonly used public protocols and protocols for Microsoft Windows. In this release, NetowrkMonitor_Parsers.msi continues to improve quality and fix bugs. It has included the fo...Duckworth Lewis Professional Edition Calculator: DLcalc 3.0: DLcalc 3.0 can perform Duckworth/Lewis Professional Edition calculations 100% accurately. It also produces over-by-over and ball-by-ball PAR score tables.Folder Bookmarks: Folder Bookmarks 2.2.0.1: In this version: Custom Icons - now you can change the icons of the bookmarks. By default, whenever an image is added, the icon is automatically changed to a thumbnail of the picture. This can be turned off in the settings (Options... > Settings) Ability to remove items from the 'Recent' category Bugfixes - 'Choose' button in 'Edit Bookmark' now works Another bug fix: another problem in the 'Edit Bookmark' windowMedia Companion: MC 3.420b Weekly: Ensure .NET 4.0 Full Framework is installed. (Available from http://www.microsoft.com/download/en/details.aspx?id=17718) Ensure the NFO ID fix is applied when transitioning from versions prior to 3.416b. (Details here) Movies Fixed: Fanart and poster scraping issues TV Shows (Re)Added: Rebuild single show Fixed: Issue when shows are moved from original location Ability to handle " for actor nicknames Crash when episode name contains "<" (does not scrape yet) Clears fanart when switch...patterns & practices - Unity: Unity 3.0 for .NET4.5 Preview: The Unity 3.0.1026.0 Preview enables Unity to work on .NET 4.5 with both the WinRT and desktop profiles. The major changes include: Unity projects updated to target .NET 4.5. Dynamic build plans modified to use compiled lambda expressions instead of Reflection.Emit Converting reflection to use the new TypeInfo for reflection. Projects updated to work with the Microsoft Visual Studio 2011 Preview Notes/Known Issues: The Microsoft.Practices.Unity.UnityServiceLocator class cannot be use...Managed Extensibility Framework: MEF 2 Preview 4: Detailed information on this release is available on the BCL team blog.Image Converter: Image Converter 0.3: New Features: - English and German support Technical Improvements: - Microsoft All Rules using Code Analysis Planned Features for future release: 1. Unit testing 2. Command line interface 3. Automatic UpdatesAcDown????? - Anime&Comic Downloader: AcDown????? v3.6: ?? ● AcDown??????????、??????，??????????????????????，???????Acfun、Bilibili、???、???、???、Tucao.cc、SF???、?????80????，???????????、?????????。 ● AcDown???????????????????????????，???，???????????????????。 ● AcDown???????C#??，????.NET Framework 2.0??。?????"Acfun?????"。 ????32??64? Windows XP/Vista/7 ????????????? ??：????????Windows XP???,?????????.NET Framework 2.0???(x86)?.NET Framework 2.0???(x64)，?????"?????????"??? ??????????????，??????????： ??"AcDown?????"????????? ?? v3.6?? ??“????”...DotNetNuke® Events: 05.02.01: This release fixes any know bugs from any previous version. Events 05.02.01 will work for any DNN version 5.5.0 and up. Full details on the changes can be found at http://dnnevents.codeplex.com/workitem/list/basic Please review and rate this release... (stars are welcome)BUG FIXESAdded validation around category cookie RSS feed was missing an explicit close of the file when writing. Fixed. Added extra security into detail view .ICS Files did not include correct line folding. Fixed Cha...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.33: Add JSParser.ParseExpression method to parse JavaScript expressions rather than source-elements. Add -strict switch (CodeSettings.StrictMode) to force input code to ECMA5 Strict-mode (extra error-checking, "use strict" at top). Fixed bug when MinifyCode setting was set to false but RemoveUnneededCode was left it's default value of true.Path Copy Copy: 8.0: New version that mostly adds lots of requested features: 11340 11339 11338 11337 This version also features a more elaborate Settings UI that has several tabs. I tried to add some notes to better explain the use and purpose of the various options. The Path Copy Copy documentation is also on the way, both to explain how to develop custom plugins and to explain how to pre-configure options if you're a network admin. Stay tuned.MVC Controls Toolkit: Mvc Controls Toolkit 1.5.0: Added: The new Client Blocks feaure of Views A new "move" js method for the TreeViews The NewHtmlCreated js event to the DataGrid Improved the ChoiceList structure that now allows also the selection list of a dropdown to be chosen with a lambda expression Improved the AcceptViewHintAttribute controller filter. Now a client can specify not only the name of a View or Partial View it prefers, but also to receive just the rough data in Json format. Fixed: Issue with partial thrust Cl...Free SharePoint Master Pages: Buried Alive (Halloween) Theme: Release Notes *Created for Halloween, you will find theme file, custom css file and images. *Created by Al Roome @AlstarRoome Features: Custom styling for web part Custom background *Screenshot https://s3.amazonaws.com/kkhipple/post/sharepoint-showcase-halloween.pngDevForce Application Framework: DevForce AF 2.0.3 RTW: PrerequisitesWPF 4.0 Silverlight 4.0 DevForce 2010 6.1.3.1 Download ContentsDebug and Release Assemblies API Documentation Source code License.txt Requirements.txt Release HighlightsNew: EventAggregator event forwarding New: EntityManagerInterceptor<T> to intercept EntityManger events New: IHarnessAware to allow for ViewModel setup when executed inside of the Development Harness New: Improved design time stability New: Support for add-in development New: CoroutineFns.To...NicAudio: NicAudio 2.0.5: Minor change to accept special DTS stereo modes (LtRt, AB,...)NDepend TFS 2010 integration: version 0.5.0 beta 1: Only the activity and the VS plugin are avalaible right now. They basically work. Data types that are logged into tfs reports are subject to change. This is no big deal since data is not yet sent into the warehouse.Windows Azure Toolkit for Windows Phone: Windows Azure Toolkit for Windows Phone v1.3.1: Upgraded Windows Azure projects to Windows Azure Tools for Microsoft Visual Studio 2010 1.5 – September 2011 Upgraded the tools tools to support the Windows Phone Developer Tools RTW Update SQL Azure only scenarios to use ASP.NET Universal Providers (through the System.Web.Providers v1.0.1 NuGet package) Changed Shared Access Signature service interface to support more operations Refactored Blobs API to have a similar interface and usage to that provided by the Windows Azure SDK Stor...DotNetNuke® FAQ: 05.00.00: FAQ (Frequently Asked Questions) 05.00.00 will work for any DNN version 5.6.1 and up. It is the first version which is rewritten in C#. The scope of this update is to fix all known issues and improve user interface. Please review and rate this release... (stars are welcome)BUG FIXESManage Categories button text was not localized Edit/Add FAQ Entry: button text was not localized ENHANCEMENTSAdded an option to select the control for category display: Listbox with checkboxes (flat category ...SiteMap Editor for Microsoft Dynamics CRM 2011: SiteMap Editor (1.0.921.340): Added CodePlex and PayPal links New iconNew ProjectsAsynk: Asynk is a framework/application that allows existing applications to easily be extended with an offloaded asynchronous worker layer. Asynk is developed using C#.Blob Tower Defense: 3D tower defense game for Windows Phone 7. School project for Brno University of Technology, computer graphics class.Booz: Booz is... An extended version of the boo shell (booish2 to be precise). Offers additional commands like cd, md, ls etc. I hope this shell can be used to take the position of/surpass the native windows shell in the near future.CIMS: a sanction infomation system for sencience and technology of hustCrystalDot - Icon Collection / Pack (LGPL): .Net / Mono freundliche Varainte der Crystal-Icons von Everaldo Icon collection / pack for .NET and Mono designed by Everaldo - KDE style http://www.everaldo.com/crystal/dotetes: dotetes adalah teka teki silang tool dikembangkan dengan bahasa c#Emoe': This Project is a Windows Phone 7.1 application.Equation Inversion: Visual Studion 2008 Add-in for equation inversions.Exploring VMR Features on WEC7: This is the sample application helps you to do alpha blending the bitmap on camera streaming in Windows Embedded Compact 7 using Directshow video Renderer (VMR). It is a VS2008 based smart device project developed on C++. I have explained the sample application in the following blog link. http://www.e-consystems.com/blog/windowsce/?p=759 EzValidation: Custom validation extensions for ASP.NET MVC 3. Includes server and client side model based validation attributes for: -- Equal To -- Not Equal To -- Greater Than -- Greater Than or Equal To -- Less Than -- Less Than or Equal To Supports validating against: -- Another Model Field -- A Specific Value -- Current Date/Yesterday/Tomorrow (for Dates and Strings) Download & Install via NuGet "package-install ezvalidation"Flu.net: Flu.net is a tool that helps you creating your own fluent syntax for .NET Framework applications in a declarative fashion. It is aimed for infrastructures and other open-source projects use.For Chess Endgames: King vs. King Opposition Calculator: You must input the locations of 2 kings on a chessboard, and whose turn it is to move. The calculator will display which king has the opposition, and how it can be used or maintained.GameTrakXNA: This project aims to create a simple library to use the unique GameTrak controller within XNA and Flash.Google Speech Recognition Example: Google Speech Recognition contains a working example of application that uses google speech recognition API. App contains all necessary dlls to record, decode and send your voice request to google service and recieve a text representation of what you've said. It's developed in C#Interval Mandelbrot Explorer: Explore the Mandelbrot set using interval arithmetic.ISD training tasks: ISD training examples and tasksiTunesControlBar: The iTunesControlBar helps user control their iTunes Application while it is minimized. iTunesControlBar resides at the top of the screen, invisible when not used, and allows playback and volume control, library searches and media information without the need to bring up iTunes.iTurtle: A bunch of Powerscripts to automate server management in AD environment.M26WC - Mono 2.6 Wizard Control: Wizard which runs under Mono2.6 A fork of: http://aerowizard.codeplex.com/Microsoft Help Viewer 2: Help Viewer 2 is the help runtime for both Visual Studio 11 help and Windows 8 help. The code in this project will help you use and understand the HV2 runtime API.MONTRASEC: Monitoring Trafficking in human beings and Sexual Exploitation of Children: benchmarking for member state and EU reporting, turning the SIAMSECT templates into a user-friendly interface and reporting tool. MTF.NET Runtime: Managed Task Framework .NET Runtime The MTF.NET runtime software and resulting assemblies are required to run applications built using the Managed Task Framework.NET Professional (Visual Studio 2010 extension) software design editor. The MTF.NET team are committed to continuously improving the core MTF.NET runtime and ensuring it is always available free and fully transparent. Pandoras Box: A greenfield inversion of control project utilising the power and flexibility of expressions and preferring convention over configuration.Pass the Puzzle: Pass the Puzzle is a frantic word-guessing party game. The game displays a few letters, and the players must come up with words containing those letters. But beware: if the timer goes off, you lose! It is based on the folk party game Pass the Parcel and is written in C#.PerCiGal: Percigal is a project for the development of applications for managing your personal media library. It consists in - a windows application to use at home to catalog movies, TV series, cast and books, with the support of the Internet for information retrieval; - a web interface for viewing and cataloging everywhere your media; - an application for smartphones. Project Flying Carpet: Este jogo é um projeto para a cadeira Projeto de Jogos: Motores Jogos do curso de Jogos Digitais da Unisinos.proxy browser: sed leo Latin's Butterfly....Python Multiple Dispatch: Multiple dispatch (AKA multimethods) for Python 3 via a metaclass and type annotations.reDune: ?????????? ???? ? ????? «????????? ? ???????? ???????». ???????? ?? Dune2000 ?? Westwood ? Electronic Arts.Rereadable: Keep page from internet for read it latter.ServStop: ServStop is a .NET application that makes it easy to stop several system services at once. Now you don't have to change startup types or stop them one at a time. It has a simple list-based interface with the ability to save and load lists of user services to stop. Written in C#.SharePoint 2010 Audience Membership Workflow Activity (Full Trust): A simple SharePoint 2010 workflow activity / workflow condition to check whether the user initiating the workflow is a member of a specified audience. Farm-level .wsp solution, written in C#. Once installed, the workflow activity can be used in SharePoint Designer 2010 declarative workflows.SQL Server® to Firebird DB converter: Converts Microsoft SQL Server® database into Firebird database including entire structure and datastegitest: test projectSystem.Threading.Joins: The Joins project provides asynchronous concurrency semantics based on join calculus and modeled after the Microsoft Research C? (C Omega) project.TestAndroidGame: try dev a TestAndroidGametetribricks: block game Topographic Explorer: A project to import, convert, explore, manipulate, and save topographical maps. Looking to use C# and WPF.Trading: Under construction!!!Trombone: Trombone makes it easier for Windows Mobile Professional users to automate status reply through SMS. It's developed in Visual C# 2008.Tulsa SharePoint Interest Group: Repository for source code for the Tulsa SharePoint Interest Group's web site. The Tulsa SharePoint Interest Group is using the Community Kit for SharePoint. This project will house any modifications that are specific to our user group.World of Tanks RU tiny stats collection utilty.: Tiny utility to load players stats for World of Tanks RU server. Results saved to comma separated file.WS-Discovery Proxy: Attempt at creating general purpose WS-Discovery Proxy.Yamaha Tu?n Tr?c: This application is used to manage information for Yamaha Tu?n Tr?c

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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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• C#/.NET Little Wonders: The Generic Func Delegates

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Back in one of my three original “Little Wonders” Trilogy of posts, I had listed generic delegates as one of the Little Wonders of .NET.  Later, someone posted a comment saying said that they would love more detail on the generic delegates and their uses, since my original entry just scratched the surface of them. Last week, I began our look at some of the handy generic delegates built into .NET with a description of delegates in general, and the Action family of delegates.  For this week, I’ll launch into a look at the Func family of generic delegates and how they can be used to support generic, reusable algorithms and classes. Quick Delegate Recap Delegates are similar to function pointers in C++ in that they allow you to store a reference to a method.  They can store references to either static or instance methods, and can actually be used to chain several methods together in one delegate. Delegates are very type-safe and can be satisfied with any standard method, anonymous method, or a lambda expression.  They can also be null as well (refers to no method), so care should be taken to make sure that the delegate is not null before you invoke it. Delegates are defined using the keyword delegate, where the delegate’s type name is placed where you would typically place the method name: 1: // This delegate matches any method that takes string, returns nothing 2: public delegate void Log(string message); This delegate defines a delegate type named Log that can be used to store references to any method(s) that satisfies its signature (whether instance, static, lambda expression, etc.). Delegate instances then can be assigned zero (null) or more methods using the operator = which replaces the existing delegate chain, or by using the operator += which adds a method to the end of a delegate chain: 1: // creates a delegate instance named currentLogger defaulted to Console.WriteLine (static method) 2: Log currentLogger = Console.Out.WriteLine; 3:  4: // invokes the delegate, which writes to the console out 5: currentLogger("Hi Standard Out!"); 6:  7: // append a delegate to Console.Error.WriteLine to go to std error 8: currentLogger += Console.Error.WriteLine; 9:  10: // invokes the delegate chain and writes message to std out and std err 11: currentLogger("Hi Standard Out and Error!"); While delegates give us a lot of power, it can be cumbersome to re-create fairly standard delegate definitions repeatedly, for this purpose the generic delegates were introduced in various stages in .NET.  These support various method types with particular signatures. Note: a caveat with generic delegates is that while they can support multiple parameters, they do not match methods that contains ref or out parameters. If you want to a delegate to represent methods that takes ref or out parameters, you will need to create a custom delegate. We’ve got the Func… delegates Just like it’s cousin, the Action delegate family, the Func delegate family gives us a lot of power to use generic delegates to make classes and algorithms more generic.  Using them keeps us from having to define a new delegate type when need to make a class or algorithm generic. Remember that the point of the Action delegate family was to be able to perform an “action” on an item, with no return results.  Thus Action delegates can be used to represent most methods that take 0 to 16 arguments but return void.  You can assign a method The Func delegate family was introduced in .NET 3.5 with the advent of LINQ, and gives us the power to define a function that can be called on 0 to 16 arguments and returns a result.  Thus, the main difference between Action and Func, from a delegate perspective, is that Actions return nothing, but Funcs return a result. The Func family of delegates have signatures as follows: Func<TResult> – matches a method that takes no arguments, and returns value of type TResult. Func<T, TResult> – matches a method that takes an argument of type T, and returns value of type TResult. Func<T1, T2, TResult> – matches a method that takes arguments of type T1 and T2, and returns value of type TResult. Func<T1, T2, …, TResult> – and so on up to 16 arguments, and returns value of type TResult. These are handy because they quickly allow you to be able to specify that a method or class you design will perform a function to produce a result as long as the method you specify meets the signature. For example, let’s say you were designing a generic aggregator, and you wanted to allow the user to define how the values will be aggregated into the result (i.e. Sum, Min, Max, etc…).  To do this, we would ask the user of our class to pass in a method that would take the current total, the next value, and produce a new total.  A class like this could look like: 1: public sealed class Aggregator<TValue, TResult> 2: { 3: // holds method that takes previous result, combines with next value, creates new result 4: private Func<TResult, TValue, TResult> _aggregationMethod; 5:  6: // gets or sets the current result of aggregation 7: public TResult Result { get; private set; } 8:  9: // construct the aggregator given the method to use to aggregate values 10: public Aggregator(Func<TResult, TValue, TResult> aggregationMethod = null) 11: { 12: if (aggregationMethod == null) throw new ArgumentNullException("aggregationMethod"); 13:  14: _aggregationMethod = aggregationMethod; 15: } 16:  17: // method to add next value 18: public void Aggregate(TValue nextValue) 19: { 20: // performs the aggregation method function on the current result and next and sets to current result 21: Result = _aggregationMethod(Result, nextValue); 22: } 23: } Of course, LINQ already has an Aggregate extension method, but that works on a sequence of IEnumerable<T>, whereas this is designed to work more with aggregating single results over time (such as keeping track of a max response time for a service). We could then use this generic aggregator to find the sum of a series of values over time, or the max of a series of values over time (among other things): 1: // creates an aggregator that adds the next to the total to sum the values 2: var sumAggregator = new Aggregator<int, int>((total, next) => total + next); 3:  4: // creates an aggregator (using static method) that returns the max of previous result and next 5: var maxAggregator = new Aggregator<int, int>(Math.Max); So, if we were timing the response time of a web method every time it was called, we could pass that response time to both of these aggregators to get an idea of the total time spent in that web method, and the max time spent in any one call to the web method: 1: // total will be 13 and max 13 2: int responseTime = 13; 3: sumAggregator.Aggregate(responseTime); 4: maxAggregator.Aggregate(responseTime); 5:  6: // total will be 20 and max still 13 7: responseTime = 7; 8: sumAggregator.Aggregate(responseTime); 9: maxAggregator.Aggregate(responseTime); 10:  11: // total will be 40 and max now 20 12: responseTime = 20; 13: sumAggregator.Aggregate(responseTime); 14: maxAggregator.Aggregate(responseTime); The Func delegate family is useful for making generic algorithms and classes, and in particular allows the caller of the method or user of the class to specify a function to be performed in order to generate a result. What is the result of a Func delegate chain? If you remember, we said earlier that you can assign multiple methods to a delegate by using the += operator to chain them.  So how does this affect delegates such as Func that return a value, when applied to something like the code below? 1: Func<int, int, int> combo = null; 2:  3: // What if we wanted to aggregate the sum and max together? 4: combo += (total, next) => total + next; 5: combo += Math.Max; 6:  7: // what is the result? 8: var comboAggregator = new Aggregator<int, int>(combo); Well, in .NET if you chain multiple methods in a delegate, they will all get invoked, but the result of the delegate is the result of the last method invoked in the chain.  Thus, this aggregator would always result in the Math.Max() result.  The other chained method (the sum) gets executed first, but it’s result is thrown away: 1: // result is 13 2: int responseTime = 13; 3: comboAggregator.Aggregate(responseTime); 4:  5: // result is still 13 6: responseTime = 7; 7: comboAggregator.Aggregate(responseTime); 8:  9: // result is now 20 10: responseTime = 20; 11: comboAggregator.Aggregate(responseTime); So remember, you can chain multiple Func (or other delegates that return values) together, but if you do so you will only get the last executed result. Func delegates and co-variance/contra-variance in .NET 4.0 Just like the Action delegate, as of .NET 4.0, the Func delegate family is contra-variant on its arguments.  In addition, it is co-variant on its return type.  To support this, in .NET 4.0 the signatures of the Func delegates changed to: Func<out TResult> – matches a method that takes no arguments, and returns value of type TResult (or a more derived type). Func<in T, out TResult> – matches a method that takes an argument of type T (or a less derived type), and returns value of type TResult(or a more derived type). Func<in T1, in T2, out TResult> – matches a method that takes arguments of type T1 and T2 (or less derived types), and returns value of type TResult (or a more derived type). Func<in T1, in T2, …, out TResult> – and so on up to 16 arguments, and returns value of type TResult (or a more derived type). Notice the addition of the in and out keywords before each of the generic type placeholders.  As we saw last week, the in keyword is used to specify that a generic type can be contra-variant -- it can match the given type or a type that is less derived.  However, the out keyword, is used to specify that a generic type can be co-variant -- it can match the given type or a type that is more derived. On contra-variance, if you are saying you need an function that will accept a string, you can just as easily give it an function that accepts an object.  In other words, if you say “give me an function that will process dogs”, I could pass you a method that will process any animal, because all dogs are animals.  On the co-variance side, if you are saying you need a function that returns an object, you can just as easily pass it a function that returns a string because any string returned from the given method can be accepted by a delegate expecting an object result, since string is more derived.  Once again, in other words, if you say “give me a method that creates an animal”, I can pass you a method that will create a dog, because all dogs are animals. It really all makes sense, you can pass a more specific thing to a less specific parameter, and you can return a more specific thing as a less specific result.  In other words, pay attention to the direction the item travels (parameters go in, results come out).  Keeping that in mind, you can always pass more specific things in and return more specific things out. For example, in the code below, we have a method that takes a Func<object> to generate an object, but we can pass it a Func<string> because the return type of object can obviously accept a return value of string as well: 1: // since Func<object> is co-variant, this will access Func<string>, etc... 2: public static string Sequence(int count, Func<object> generator) 3: { 4: var builder = new StringBuilder(); 5:  6: for (int i=0; i<count; i++) 7: { 8: object value = generator(); 9: builder.Append(value); 10: } 11:  12: return builder.ToString(); 13: } Even though the method above takes a Func<object>, we can pass a Func<string> because the TResult type placeholder is co-variant and accepts types that are more derived as well: 1: // delegate that's typed to return string. 2: Func<string> stringGenerator = () => DateTime.Now.ToString(); 3:  4: // This will work in .NET 4.0, but not in previous versions 5: Sequence(100, stringGenerator); Previous versions of .NET implemented some forms of co-variance and contra-variance before, but .NET 4.0 goes one step further and allows you to pass or assign an Func<A, BResult> to a Func<Y, ZResult> as long as A is less derived (or same) as Y, and BResult is more derived (or same) as ZResult. Sidebar: The Func and the Predicate A method that takes one argument and returns a bool is generally thought of as a predicate.  Predicates are used to examine an item and determine whether that item satisfies a particular condition.  Predicates are typically unary, but you may also have binary and other predicates as well. Predicates are often used to filter results, such as in the LINQ Where() extension method: 1: var numbers = new[] { 1, 2, 4, 13, 8, 10, 27 }; 2:  3: // call Where() using a predicate which determines if the number is even 4: var evens = numbers.Where(num => num % 2 == 0); As of .NET 3.5, predicates are typically represented as Func<T, bool> where T is the type of the item to examine.  Previous to .NET 3.5, there was a Predicate<T> type that tended to be used (which we’ll discuss next week) and is still supported, but most developers recommend using Func<T, bool> now, as it prevents confusion with overloads that accept unary predicates and binary predicates, etc.: 1: // this seems more confusing as an overload set, because of Predicate vs Func 2: public static SomeMethod(Predicate<int> unaryPredicate) { } 3: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } 4:  5: // this seems more consistent as an overload set, since just uses Func 6: public static SomeMethod(Func<int, bool> unaryPredicate) { } 7: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } Also, even though Predicate<T> and Func<T, bool> match the same signatures, they are separate types!  Thus you cannot assign a Predicate<T> instance to a Func<T, bool> instance and vice versa: 1: // the same method, lambda expression, etc can be assigned to both 2: Predicate<int> isEven = i => (i % 2) == 0; 3: Func<int, bool> alsoIsEven = i => (i % 2) == 0; 4:  5: // but the delegate instances cannot be directly assigned, strongly typed! 6: // ERROR: cannot convert type... 7: isEven = alsoIsEven; 8:  9: // however, you can assign by wrapping in a new instance: 10: isEven = new Predicate<int>(alsoIsEven); 11: alsoIsEven = new Func<int, bool>(isEven); So, the general advice that seems to come from most developers is that Predicate<T> is still supported, but we should use Func<T, bool> for consistency in .NET 3.5 and above. Sidebar: Func as a Generator for Unit Testing One area of difficulty in unit testing can be unit testing code that is based on time of day.  We’d still want to unit test our code to make sure the logic is accurate, but we don’t want the results of our unit tests to be dependent on the time they are run. One way (of many) around this is to create an internal generator that will produce the “current” time of day.  This would default to returning result from DateTime.Now (or some other method), but we could inject specific times for our unit testing.  Generators are typically methods that return (generate) a value for use in a class/method. For example, say we are creating a CacheItem<T> class that represents an item in the cache, and we want to make sure the item shows as expired if the age is more than 30 seconds.  Such a class could look like: 1: // responsible for maintaining an item of type T in the cache 2: public sealed class CacheItem<T> 3: { 4: // helper method that returns the current time 5: private static Func<DateTime> _timeGenerator = () => DateTime.Now; 6:  7: // allows internal access to the time generator 8: internal static Func<DateTime> TimeGenerator 9: { 10: get { return _timeGenerator; } 11: set { _timeGenerator = value; } 12: } 13:  14: // time the item was cached 15: public DateTime CachedTime { get; private set; } 16:  17: // the item cached 18: public T Value { get; private set; } 19:  20: // item is expired if older than 30 seconds 21: public bool IsExpired 22: { 23: get { return _timeGenerator() - CachedTime > TimeSpan.FromSeconds(30.0); } 24: } 25:  26: // creates the new cached item, setting cached time to "current" time 27: public CacheItem(T value) 28: { 29: Value = value; 30: CachedTime = _timeGenerator(); 31: } 32: } Then, we can use this construct to unit test our CacheItem<T> without any time dependencies: 1: var baseTime = DateTime.Now; 2:  3: // start with current time stored above (so doesn't drift) 4: CacheItem<int>.TimeGenerator = () => baseTime; 5:  6: var target = new CacheItem<int>(13); 7:  8: // now add 15 seconds, should still be non-expired 9: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(15); 10:  11: Assert.IsFalse(target.IsExpired); 12:  13: // now add 31 seconds, should now be expired 14: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(31); 15:  16: Assert.IsTrue(target.IsExpired); Now we can unit test for 1 second before, 1 second after, 1 millisecond before, 1 day after, etc.  Func delegates can be a handy tool for this type of value generation to support more testable code.  Summary Generic delegates give us a lot of power to make truly generic algorithms and classes.  The Func family of delegates is a great way to be able to specify functions to calculate a result based on 0-16 arguments.  Stay tuned in the weeks that follow for other generic delegates in the .NET Framework!   Tweet Technorati Tags: .NET, C#, CSharp, Little Wonders, Generics, Func, Delegates

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• How to create Custom ListForm WebPart

  - by DipeshBhanani

  Mostly all who works extensively on SharePoint (including meJ) don’t like to use out-of-box list forms (DispForm.aspx, EditForm.aspx, NewForm.aspx) as interface. Actually these OOB list forms bind hands of developers for the customization. It gives headache to developers to add just one post back event, for a dropdown field and to populate other fields in NewForm.aspx or EditForm.aspx. On top of that clients always ask such stuff. So here I am going to give you guys a flight for SharePoint Customization world. In this blog, I will explain, how to create CustomListForm WebPart. In my next blogs, I am going to explain easy deployment of List Forms through features and last, guidance on using SharePoint web controls. 1.       First thing, create a class library project through Visual Studio and inherit the class with WebPart class.     public class CustomListForm : WebPart   2.       Declare the public variables and properties which we are going to use throughout the class. You will get to know these once you see them in use.         #region "Variable Declaration"           Table spTableCntl;         FormToolBar formToolBar;         Literal ltAlertMessage;         Guid SiteId;         Guid ListId;         int ItemId;         string ListName;           #endregion           #region "Properties"           SPControlMode _ControlMode = SPControlMode.New;         [Personalizable(PersonalizationScope.Shared),          WebBrowsable(true),          WebDisplayName("Control Mode"),          WebDescription("Set Control Mode"),          DefaultValue(""),          Category("Miscellaneous")]         public SPControlMode ControlMode         {             get { return _ControlMode; }             set { _ControlMode = value; }         }           #endregion     The property “ControlMode” is used to identify the mode of the List Form. The property is of type SPControlMode which is an enum type with values (Display, Edit, New and Invalid). When we will add this WebPart to DispForm.aspx, EditForm.aspx and NewForm.aspx, we will set the WebPart property “ControlMode” to Display, Edit and New respectively.     3.       Now, we need to override the CreateChildControl method and write code to manually add SharePoint Web Controls related to each list fields as well as ToolBar controls.         protected override void CreateChildControls()         {             base.CreateChildControls();               try             {                 SiteId = SPContext.Current.Site.ID;                 ListId = SPContext.Current.ListId;                 ListName = SPContext.Current.List.Title;                   if (_ControlMode == SPControlMode.Display || _ControlMode == SPControlMode.Edit)                     ItemId = SPContext.Current.ItemId;                   SPSecurity.RunWithElevatedPrivileges(delegate()                 {                     using (SPSite site = new SPSite(SiteId))                     {                         //creating a new SPSite with credentials of System Account                         using (SPWeb web = site.OpenWeb())                         {                               //<Custom Code for creating form controls>                         }                     }                 });             }             catch (Exception ex)             {                 ShowError(ex, "CreateChildControls");             }         }   Here we are assuming that we are developing this WebPart to plug into List Forms. Hence we will get the List Id and List Name from the current context. We can have Item Id only in case of Display and Edit Mode. We are putting our code into “RunWithElevatedPrivileges” to elevate privileges to System Account. Now, let’s get deep down into the main code and expand “//<Custom Code for creating form controls>”. Before initiating any SharePoint control, we need to set context of SharePoint web controls explicitly so that it will be instantiated with elevated System Account user. Following line does the job.     //To create SharePoint controls with new web object and System Account credentials     SPControl.SetContextWeb(Context, web);   First thing, let’s add main table as container for all controls.     //Table to render webpart     Table spTableMain = new Table();     spTableMain.CellPadding = 0;     spTableMain.CellSpacing = 0;     spTableMain.Width = new Unit(100, UnitType.Percentage);     this.Controls.Add(spTableMain);   Now we need to add Top toolbar with Save and Cancel button at top as you see in the below screen shot.       // Add Row and Cell for Top ToolBar     TableRow spRowTopToolBar = new TableRow();     spTableMain.Rows.Add(spRowTopToolBar);     TableCell spCellTopToolBar = new TableCell();     spRowTopToolBar.Cells.Add(spCellTopToolBar);     spCellTopToolBar.Width = new Unit(100, UnitType.Percentage);         ToolBar toolBarTop = (ToolBar)Page.LoadControl("/_controltemplates/ToolBar.ascx");     toolBarTop.CssClass = "ms-formtoolbar";     toolBarTop.ID = "toolBarTbltop";     toolBarTop.RightButtons.SeparatorHtml = "<td class=ms-separator> </td>";       if (_ControlMode != SPControlMode.Display)     {         SaveButton btnSave = new SaveButton();         btnSave.ControlMode = _ControlMode;         btnSave.ListId = ListId;           if (_ControlMode == SPControlMode.New)             btnSave.RenderContext = SPContext.GetContext(web);         else         {             btnSave.RenderContext = SPContext.GetContext(this.Context, ItemId, ListId, web);             btnSave.ItemContext = SPContext.GetContext(this.Context, ItemId, ListId, web);             btnSave.ItemId = ItemId;         }         toolBarTop.RightButtons.Controls.Add(btnSave);     }       GoBackButton goBackButtonTop = new GoBackButton();     toolBarTop.RightButtons.Controls.Add(goBackButtonTop);     goBackButtonTop.ControlMode = SPControlMode.Display;       spCellTopToolBar.Controls.Add(toolBarTop);   Here we have use “SaveButton” and “GoBackButton” which are internal SharePoint web controls for save and cancel functionality. I have set some of the properties of Save Button with if-else condition because we will not have Item Id in case of New Mode. Item Id property is used to identify which SharePoint List Item need to be saved. Now, add Form Toolbar to the page which contains “Attach File”, “Delete Item” etc buttons.       // Add Row and Cell for FormToolBar     TableRow spRowFormToolBar = new TableRow();     spTableMain.Rows.Add(spRowFormToolBar);     TableCell spCellFormToolBar = new TableCell();     spRowFormToolBar.Cells.Add(spCellFormToolBar);     spCellFormToolBar.Width = new Unit(100, UnitType.Percentage);       FormToolBar formToolBar = new FormToolBar();     formToolBar.ID = "formToolBar";     formToolBar.ListId = ListId;     if (_ControlMode == SPControlMode.New)         formToolBar.RenderContext = SPContext.GetContext(web);     else     {         formToolBar.RenderContext = SPContext.GetContext(this.Context, ItemId, ListId, web);         formToolBar.ItemContext = SPContext.GetContext(this.Context, ItemId, ListId, web);         formToolBar.ItemId = ItemId;     }     formToolBar.ControlMode = _ControlMode;     formToolBar.EnableViewState = true;       spCellFormToolBar.Controls.Add(formToolBar);     The ControlMode property will take care of which button to be displayed on the toolbar. E.g. “Attach files”, “Delete Item” in new/edit forms and “New Item”, “Edit Item”, “Delete Item”, “Manage Permissions” etc in display forms. Now add main section which contains form field controls.     //Create Form Field controls and add them in Table "spCellCntl"     CreateFieldControls(web);     //Add public variable "spCellCntl" containing all form controls to the page     spRowCntl.Cells.Add(spCellCntl);     spCellCntl.Width = new Unit(100, UnitType.Percentage);     spCellCntl.Controls.Add(spTableCntl);       //Add a Blank Row with height of 5px to render space between ToolBar table and Control table     TableRow spRowLine1 = new TableRow();     spTableMain.Rows.Add(spRowLine1);     TableCell spCellLine1 = new TableCell();     spRowLine1.Cells.Add(spCellLine1);     spCellLine1.Height = new Unit(5, UnitType.Pixel);     spCellLine1.Controls.Add(new LiteralControl("<IMG SRC='/_layouts/images/blank.gif' width=1 height=1 alt=''>"));       //Add Row and Cell for Form Controls Section     TableRow spRowCntl = new TableRow();     spTableMain.Rows.Add(spRowCntl);     TableCell spCellCntl = new TableCell();       //Create Form Field controls and add them in Table "spCellCntl"     CreateFieldControls(web);     //Add public variable "spCellCntl" containing all form controls to the page     spRowCntl.Cells.Add(spCellCntl);     spCellCntl.Width = new Unit(100, UnitType.Percentage);     spCellCntl.Controls.Add(spTableCntl);       TableRow spRowLine2 = new TableRow();     spTableMain.Rows.Add(spRowLine2);     TableCell spCellLine2 = new TableCell();     spRowLine2.Cells.Add(spCellLine2);     spCellLine2.CssClass = "ms-formline";     spCellLine2.Controls.Add(new LiteralControl("<IMG SRC='/_layouts/images/blank.gif' width=1 height=1 alt=''>"));       // Add Blank row with height of 5 pixel     TableRow spRowLine3 = new TableRow();     spTableMain.Rows.Add(spRowLine3);     TableCell spCellLine3 = new TableCell();     spRowLine3.Cells.Add(spCellLine3);     spCellLine3.Height = new Unit(5, UnitType.Pixel);     spCellLine3.Controls.Add(new LiteralControl("<IMG SRC='/_layouts/images/blank.gif' width=1 height=1 alt=''>"));   You can add bottom toolbar also to get same look and feel as OOB forms. I am not adding here as the blog will be much lengthy. At last, you need to write following lines to allow unsafe updates for Save and Delete button.     // Allow unsafe update on web for save button and delete button     if (this.Page.IsPostBack && this.Page.Request["__EventTarget"] != null         && (this.Page.Request["__EventTarget"].Contains("IOSaveItem")         || this.Page.Request["__EventTarget"].Contains("IODeleteItem")))     {         SPContext.Current.Web.AllowUnsafeUpdates = true;     }   So that’s all. We have finished writing Custom Code for adding field control. But something most important is skipped. In above code, I have called function “CreateFieldControls(web);” to add SharePoint field controls to the page. Let’s see the implementation of the function:     private void CreateFieldControls(SPWeb pWeb)     {         SPList listMain = pWeb.Lists[ListId];         SPFieldCollection fields = listMain.Fields;           //Main Table to render all fields         spTableCntl = new Table();         spTableCntl.BorderWidth = new Unit(0);         spTableCntl.CellPadding = 0;         spTableCntl.CellSpacing = 0;         spTableCntl.Width = new Unit(100, UnitType.Percentage);         spTableCntl.CssClass = "ms-formtable";           SPContext controlContext = SPContext.GetContext(this.Context, ItemId, ListId, pWeb);           foreach (SPField listField in fields)         {             string fieldDisplayName = listField.Title;             string fieldInternalName = listField.InternalName;               //Skip if the field is system field or hidden             if (listField.Hidden || listField.ShowInVersionHistory == false)                 continue;               //Skip if the control mode is display and field is read-only             if (_ControlMode != SPControlMode.Display && listField.ReadOnlyField == true)                 continue;               FieldLabel fieldLabel = new FieldLabel();             fieldLabel.FieldName = listField.InternalName;             fieldLabel.ListId = ListId;               BaseFieldControl fieldControl = listField.FieldRenderingControl;             fieldControl.ListId = ListId;             //Assign unique id using Field Internal Name             fieldControl.ID = string.Format("Field_{0}", fieldInternalName);             fieldControl.EnableViewState = true;               //Assign control mode             fieldLabel.ControlMode = _ControlMode;             fieldControl.ControlMode = _ControlMode;             switch (_ControlMode)             {                 case SPControlMode.New:                     fieldLabel.RenderContext = SPContext.GetContext(pWeb);                     fieldControl.RenderContext = SPContext.GetContext(pWeb);                     break;                 case SPControlMode.Edit:                 case SPControlMode.Display:                     fieldLabel.RenderContext = controlContext;                     fieldLabel.ItemContext = controlContext;                     fieldLabel.ItemId = ItemId;                       fieldControl.RenderContext = controlContext;                     fieldControl.ItemContext = controlContext;                     fieldControl.ItemId = ItemId;                     break;             }               //Add row to display a field row             TableRow spCntlRow = new TableRow();             spTableCntl.Rows.Add(spCntlRow);               //Add the cells for containing field lable and control             TableCell spCellLabel = new TableCell();             spCellLabel.Width = new Unit(30, UnitType.Percentage);             spCellLabel.CssClass = "ms-formlabel";             spCntlRow.Cells.Add(spCellLabel);             TableCell spCellControl = new TableCell();             spCellControl.Width = new Unit(70, UnitType.Percentage);             spCellControl.CssClass = "ms-formbody";             spCntlRow.Cells.Add(spCellControl);               //Add the control to the table cells             spCellLabel.Controls.Add(fieldLabel);             spCellControl.Controls.Add(fieldControl);               //Add description if there is any in case of New and Edit Mode             if (_ControlMode != SPControlMode.Display && listField.Description != string.Empty)             {                 FieldDescription fieldDesc = new FieldDescription();                 fieldDesc.FieldName = fieldInternalName;                 fieldDesc.ListId = ListId;                 spCellControl.Controls.Add(fieldDesc);             }               //Disable Name(Title) in Edit Mode             if (_ControlMode == SPControlMode.Edit && fieldDisplayName == "Name")             {                 TextBox txtTitlefield = (TextBox)fieldControl.Controls[0].FindControl("TextField");                 txtTitlefield.Enabled = false;             }         }         fields = null;     }   First of all, I have declared List object and got list fields in field collection object called “fields”. Then I have added a table for the container of all controls and assign CSS class as "ms-formtable" so that it gives consistent look and feel of SharePoint. Now it’s time to navigate through all fields and add them if required. Here we don’t need to add hidden or system fields. We also don’t want to display read-only fields in new and edit forms. Following lines does this job.             //Skip if the field is system field or hidden             if (listField.Hidden || listField.ShowInVersionHistory == false)                 continue;               //Skip if the control mode is display and field is read-only             if (_ControlMode != SPControlMode.Display && listField.ReadOnlyField == true)                 continue;   Let’s move to the next line of code.             FieldLabel fieldLabel = new FieldLabel();             fieldLabel.FieldName = listField.InternalName;             fieldLabel.ListId = ListId;               BaseFieldControl fieldControl = listField.FieldRenderingControl;             fieldControl.ListId = ListId;             //Assign unique id using Field Internal Name             fieldControl.ID = string.Format("Field_{0}", fieldInternalName);             fieldControl.EnableViewState = true;               //Assign control mode             fieldLabel.ControlMode = _ControlMode;             fieldControl.ControlMode = _ControlMode;   We have used “FieldLabel” control for displaying field title. The advantage of using Field Label is, SharePoint automatically adds red star besides field label to identify it as mandatory field if there is any. Here is most important part to understand. The “BaseFieldControl”. It will render the respective web controls according to type of the field. For example, if it’s single line of text, then Textbox, if it’s look up then it renders dropdown. Additionally, the “ControlMode” property tells compiler that which mode (display/edit/new) controls need to be rendered with. In display mode, it will render label with field value. In edit mode, it will render respective control with item value and in new mode it will render respective control with empty value. Please note that, it’s not always the case when dropdown field will be rendered for Lookup field or Choice field. You need to understand which controls are rendered for which list fields. I am planning to write a separate blog which I hope to publish it very soon. Moreover, we also need to assign list field specific properties like List Id, Field Name etc to identify which SharePoint List field is attached with the control.             switch (_ControlMode)             {                 case SPControlMode.New:                     fieldLabel.RenderContext = SPContext.GetContext(pWeb);                     fieldControl.RenderContext = SPContext.GetContext(pWeb);                     break;                 case SPControlMode.Edit:                 case SPControlMode.Display:                     fieldLabel.RenderContext = controlContext;                     fieldLabel.ItemContext = controlContext;                     fieldLabel.ItemId = ItemId;                       fieldControl.RenderContext = controlContext;                     fieldControl.ItemContext = controlContext;                     fieldControl.ItemId = ItemId;                     break;             }   Here, I have separate code for new mode and Edit/Display mode because we will not have Item Id to assign in New Mode. We also need to set CSS class for cell containing Label and Controls so that those controls get rendered with SharePoint theme.             spCellLabel.CssClass = "ms-formlabel";             spCellControl.CssClass = "ms-formbody";   “FieldDescription” control is used to add field description if there is any.    Now it’s time to add some more customization,               //Disable Name(Title) in Edit Mode             if (_ControlMode == SPControlMode.Edit && fieldDisplayName == "Name")             {                 TextBox txtTitlefield = (TextBox)fieldControl.Controls[0].FindControl("TextField");                 txtTitlefield.Enabled = false;             }   The above code will disable the title field in edit mode. You can add more code here to achieve more customization according to your requirement. Some of the examples are as follow:             //Adding post back event on UserField to auto populate some other dependent field             //in new mode and disable it in edit mode             if (_ControlMode != SPControlMode.Display && fieldDisplayName == "Manager")             {                 if (fieldControl.Controls[0].FindControl("UserField") != null)                 {                     PeopleEditor pplEditor = (PeopleEditor)fieldControl.Controls[0].FindControl("UserField");                     if (_ControlMode == SPControlMode.New)                         pplEditor.AutoPostBack = true;                     else                         pplEditor.Enabled = false;                 }             }               //Add JavaScript Event on Dropdown field. Don't forget to add the JavaScript function on the page.             if (_ControlMode == SPControlMode.Edit && fieldDisplayName == "Designation")             {                 DropDownList ddlCategory = (DropDownList)fieldControl.Controls[0];                 ddlCategory.Attributes.Add("onchange", string.Format("javascript:DropdownChangeEvent('{0}');return false;", ddlCategory.ClientID));             }    Following are the screenshots of my Custom ListForm WebPart. Let’s play a game, check out your OOB List forms of SharePoint, compare with these screens and find out differences.   DispForm.aspx:   EditForm.aspx:   NewForm.aspx:   Enjoy the SharePoint Soup!!! ­­­­­­­­­­­­­­­­­­­­

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• Implementing an async "read all currently available data from stream" operation

  - by Jon

  I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a console's standard output Stream. Console output streams are of type FileStream; the implementation can cast to that, if needed. There is also an associated StreamReader already present to leverage. There is only one thing I need to implement in this class to achieve my desired functionality: an async "read all the data available this moment" operation. Reading to the end of the stream is not viable because the stream will not end unless the process closes the console output handle, and it will not do that because it is interactive and expecting input before continuing. I will be using that hypothetical async operation to implement event-based notification, which will be more convenient for my callers. The public interface of the class is this: public class ConsoleAutomator { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Remember that the goal here is to read all of the chunk and call event subscribers exactly once for each chunk. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream. private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer (in which case we know that there was no more data to be read during the last read operation), all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Never more than one event for each time data is available to be read Is almost agnostic to the buffer size The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this. Update: I definitely did not communicate the scenario well in my initial writeup. I have since revised the writeup quite a bit, but to be extra sure: The question is about how to implement an async "read all the data available this moment" operation. My apologies to the people who took the time to read and answer without me making my intent clear enough.

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• XSLT typograph.

  - by kalininew

  Divide a large amount of text on an arbitrary number of equal parts. I probably already fed up with their stupid questions, but I have one more question. I have a large piece of text <p> Sed ut perspiciatis, unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam eaque ipsa, quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt, explicabo. Nemo enim ipsam voluptatem, quia voluptas sit, </p> <p> aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos, qui ratione voluptatem sequi nesciunt, neque porro quisquam est, qui dolorem ipsum, quia dolor sit, amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt, ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? </p> <p> Quis autem vel eum iure reprehenderit, qui in ea voluptate velit esse, quam nihil molestiae consequatur, vel illum, qui dolorem eum fugiat, quo voluptas nulla pariatur? At vero eos et accusamus et iusto odio dignissimos ducimus, qui blanditiis praesentium voluptatum deleniti atque corrupti, quos dolores et quas molestias excepturi sint, obcaecati cupiditate non provident, similique sunt in culpa, qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum </p> <p> soluta nobis est eligendi optio, cumque nihil impedit, quo minus id, quod maxime placeat, facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Temporibus autem quibusdam et aut officiis debitis aut rerum necessitatibus saepe eveniet, ut et voluptates repudiandae sint et molestiae non recusandae. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat. </p> <p> Sed ut perspiciatis, unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam eaque ipsa, quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt, explicabo. Nemo enim ipsam voluptatem, quia voluptas sit, </p> <p> Sed ut perspiciatis, unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam eaque ipsa, quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt, explicabo. Nemo enim ipsam voluptatem, quia voluptas sit, </p> <p> aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos, qui ratione voluptatem sequi nesciunt, neque porro quisquam est, qui dolorem ipsum, quia dolor sit, amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt, ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? </p> <p> Quis autem vel eum iure reprehenderit, qui in ea voluptate velit esse, quam nihil molestiae consequatur, vel illum, qui dolorem eum fugiat, quo voluptas nulla pariatur? At vero eos et accusamus et iusto odio dignissimos ducimus, qui blanditiis praesentium voluptatum deleniti atque corrupti, quos dolores et quas molestias excepturi sint, obcaecati cupiditate non provident, similique sunt in culpa, qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum </p> <p> soluta nobis est eligendi optio, cumque nihil impedit, quo minus id, quod maxime placeat, facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Temporibus autem quibusdam et aut officiis debitis aut rerum necessitatibus saepe eveniet, ut et voluptates repudiandae sint et molestiae non recusandae. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat. </p> <p> Quis autem vel eum iure reprehenderit, qui in ea voluptate velit esse, quam nihil molestiae consequatur, vel illum, qui dolorem eum fugiat, quo voluptas nulla pariatur? At vero eos et accusamus et iusto odio dignissimos ducimus, qui blanditiis praesentium voluptatum deleniti atque corrupti, quos dolores et quas molestias excepturi sint, obcaecati cupiditate non provident, similique sunt in culpa, qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum </p> <p> Sed ut perspiciatis, unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam eaque ipsa, quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt, explicabo. Nemo enim ipsam voluptatem, quia voluptas sit, </p> <p> soluta nobis est eligendi optio, cumque nihil impedit, quo minus id, quod maxime placeat, facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Temporibus autem quibusdam et aut officiis debitis aut rerum necessitatibus saepe eveniet, ut et voluptates repudiandae sint et molestiae non recusandae. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat. </p> <p> Sed ut perspiciatis, unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam eaque ipsa, quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt, explicabo. Nemo enim ipsam voluptatem, quia voluptas sit, </p> At the exit I need to divide the text on the "n" equal parts, so that in these parts was about the same amount of text. Then I these part are arranged in columns and the need for these columns look about the same height. Another condition: Tags you can break (I mean that if the tag "p" contains a lot of text, it can be divided into two parts, to bring in another column). I think this is a monumental task, I shall be grateful for any help. I understand that XSLT is not typography tool. But it is possible divide the text into parts with the same number of characters in each

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• Class member functions instantiated by traits [policies, actually]

  - by Jive Dadson

  I am reluctant to say I can't figure this out, but I can't figure this out. I've googled and searched Stack Overflow, and come up empty. The abstract, and possibly overly vague form of the question is, how can I use the traits-pattern to instantiate member functions? [Update: I used the wrong term here. It should be "policies" rather than "traits." Traits describe existing classes. Policies prescribe synthetic classes.] The question came up while modernizing a set of multivariate function optimizers that I wrote more than 10 years ago. The optimizers all operate by selecting a straight-line path through the parameter space away from the current best point (the "update"), then finding a better point on that line (the "line search"), then testing for the "done" condition, and if not done, iterating. There are different methods for doing the update, the line-search, and conceivably for the done test, and other things. Mix and match. Different update formulae require different state-variable data. For example, the LMQN update requires a vector, and the BFGS update requires a matrix. If evaluating gradients is cheap, the line-search should do so. If not, it should use function evaluations only. Some methods require more accurate line-searches than others. Those are just some examples. The original version instantiates several of the combinations by means of virtual functions. Some traits are selected by setting mode bits that are tested at runtime. Yuck. It would be trivial to define the traits with #define's and the member functions with #ifdef's and macros. But that's so twenty years ago. It bugs me that I cannot figure out a whiz-bang modern way. If there were only one trait that varied, I could use the curiously recurring template pattern. But I see no way to extend that to arbitrary combinations of traits. I tried doing it using boost::enable_if, etc.. The specialized state information was easy. I managed to get the functions done, but only by resorting to non-friend external functions that have the this-pointer as a parameter. I never even figured out how to make the functions friends, much less member functions. The compiler (VC++ 2008) always complained that things didn't match. I would yell, "SFINAE, you moron!" but the moron is probably me. Perhaps tag-dispatch is the key. I haven't gotten very deeply into that. Surely it's possible, right? If so, what is best practice? UPDATE: Here's another try at explaining it. I want the user to be able to fill out an order (manifest) for a custom optimizer, something like ordering off of a Chinese menu - one from column A, one from column B, etc.. Waiter, from column A (updaters), I'll have the BFGS update with Cholesky-decompositon sauce. From column B (line-searchers), I'll have the cubic interpolation line-search with an eta of 0.4 and a rho of 1e-4, please. Etc... UPDATE: Okay, okay. Here's the playing-around that I've done. I offer it reluctantly, because I suspect it's a completely wrong-headed approach. It runs okay under vc++ 2008. #include <boost/utility.hpp> #include <boost/type_traits/integral_constant.hpp> namespace dj { struct CBFGS { void bar() {printf("CBFGS::bar %d\n", data);} CBFGS(): data(1234){} int data; }; template<class T> struct is_CBFGS: boost::false_type{}; template<> struct is_CBFGS<CBFGS>: boost::true_type{}; struct LMQN {LMQN(): data(54.321){} void bar() {printf("LMQN::bar %lf\n", data);} double data; }; template<class T> struct is_LMQN: boost::false_type{}; template<> struct is_LMQN<LMQN> : boost::true_type{}; // "Order form" struct default_optimizer_traits { typedef CBFGS update_type; // Selection from column A - updaters }; template<class traits> class Optimizer; template<class traits> void foo(typename boost::enable_if<is_LMQN<typename traits::update_type>, Optimizer<traits> >::type& self) { printf(" LMQN %lf\n", self.data); } template<class traits> void foo(typename boost::enable_if<is_CBFGS<typename traits::update_type>, Optimizer<traits> >::type& self) { printf("CBFGS %d\n", self.data); } template<class traits = default_optimizer_traits> class Optimizer{ friend typename traits::update_type; //friend void dj::foo<traits>(typename Optimizer<traits> & self); // How? public: //void foo(void); // How??? void foo() { dj::foo<traits>(*this); } void bar() { data.bar(); } //protected: // How? typedef typename traits::update_type update_type; update_type data; }; } // namespace dj int main() { dj::Optimizer<> opt; opt.foo(); opt.bar(); std::getchar(); return 0; }

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• Implementing a robust async stream reader

  - by Jon

  I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output, but that is a detail and does not play an important role. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

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• Mysql - help me optimize this query

  - by sandeepan-nath

  About the system: -The system has a total of 8 tables - Users - Tutor_Details (Tutors are a type of User,Tutor_Details table is linked to Users) - learning_packs, (stores packs created by tutors) - learning_packs_tag_relations, (holds tag relations meant for search) - tutors_tag_relations and tags and orders (containing purchase details of tutor's packs), order_details linked to orders and tutor_details. For a more clear idea about the tables involved please check the The tables section in the end. -A tags based search approach is being followed.Tag relations are created when new tutors register and when tutors create packs (this makes tutors and packs searcheable). For details please check the section How tags work in this system? below. Following is a simpler representation (not the actual) of the more complex query which I am trying to optimize:- I have used statements like explanation of parts in the query select SUM(DISTINCT( t.tag LIKE "%Dictatorship%" )) as key_1_total_matches, SUM(DISTINCT( t.tag LIKE "%democracy%" )) as key_2_total_matches, td., u., count(distinct(od.id_od)), if (lp.id_lp > 0) then some conditional logic on lp fields else 0 as tutor_popularity from Tutor_Details AS td JOIN Users as u on u.id_user = td.id_user LEFT JOIN Learning_Packs_Tag_Relations AS lptagrels ON td.id_tutor = lptagrels.id_tutor LEFT JOIN Learning_Packs AS lp ON lptagrels.id_lp = lp.id_lp LEFT JOIN `some other tables on lp.id_lp - let's call learning pack tables set (including Learning_Packs table)` LEFT JOIN Order_Details as od on td.id_tutor = od.id_author LEFT JOIN Orders as o on od.id_order = o.id_order LEFT JOIN Tutors_Tag_Relations as ttagrels ON td.id_tutor = ttagrels.id_tutor JOIN Tags as t on (t.id_tag = ttagrels.id_tag) OR (t.id_tag = lptagrels.id_tag) where some condition on Users table's fields AND CASE WHEN ((t.id_tag = lptagrels.id_tag) AND (lp.id_lp 0)) THEN `some conditions on learning pack tables set` ELSE 1 END AND CASE WHEN ((t.id_tag = wtagrels.id_tag) AND (wc.id_wc 0)) THEN `some conditions on webclasses tables set` ELSE 1 END AND CASE WHEN (od.id_od0) THEN od.id_author = td.id_tutor and some conditions on Orders table's fields ELSE 1 END AND ( t.tag LIKE "%Dictatorship%" OR t.tag LIKE "%democracy%") group by td.id_tutor HAVING key_1_total_matches = 1 AND key_2_total_matches = 1 order by tutor_popularity desc, u.surname asc, u.name asc limit 0,20 ===================================================================== What does the above query do? Does AND logic search on the search keywords (2 in this example - "Democracy" and "Dictatorship"). Returns only those tutors for which both the keywords are present in the union of the two sets - tutors details and details of all the packs created by a tutor. To make things clear - Suppose a Tutor name "Sandeepan Nath" has created a pack "My first pack", then:- Searching "Sandeepan Nath" returns Sandeepan Nath. Searching "Sandeepan first" returns Sandeepan Nath. Searching "Sandeepan second" does not return Sandeepan Nath. ====================================================================================== The problem The results returned by the above query are correct (AND logic working as per expectation), but the time taken by the query on heavily loaded databases is like 25 seconds as against normal query timings of the order of 0.005 - 0.0002 seconds, which makes it totally unusable. It is possible that some of the delay is being caused because all the possible fields have not yet been indexed, but I would appreciate a better query as a solution, optimized as much as possible, displaying the same results ========================================================================================== How tags work in this system? When a tutor registers, tags are entered and tag relations are created with respect to tutor's details like name, surname etc. When a Tutors create packs, again tags are entered and tag relations are created with respect to pack's details like pack name, description etc. tag relations for tutors stored in tutors_tag_relations and those for packs stored in learning_packs_tag_relations. All individual tags are stored in tags table. ==================================================================== The tables Most of the following tables contain many other fields which I have omitted here. CREATE TABLE IF NOT EXISTS users ( id_user int(10) unsigned NOT NULL AUTO_INCREMENT, name varchar(100) NOT NULL DEFAULT '', surname varchar(155) NOT NULL DEFAULT '', PRIMARY KEY (id_user) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=636 ; CREATE TABLE IF NOT EXISTS tutor_details ( id_tutor int(10) NOT NULL AUTO_INCREMENT, id_user int(10) NOT NULL DEFAULT '0', PRIMARY KEY (id_tutor), KEY Users_FKIndex1 (id_user) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=51 ; CREATE TABLE IF NOT EXISTS orders ( id_order int(10) unsigned NOT NULL AUTO_INCREMENT, PRIMARY KEY (id_order), KEY Orders_FKIndex1 (id_user), ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=275 ; ALTER TABLE orders ADD CONSTRAINT Orders_ibfk_1 FOREIGN KEY (id_user) REFERENCES users (id_user) ON DELETE NO ACTION ON UPDATE NO ACTION; CREATE TABLE IF NOT EXISTS order_details ( id_od int(10) unsigned NOT NULL AUTO_INCREMENT, id_order int(10) unsigned NOT NULL DEFAULT '0', id_author int(10) NOT NULL DEFAULT '0', PRIMARY KEY (id_od), KEY Order_Details_FKIndex1 (id_order) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=284 ; ALTER TABLE order_details ADD CONSTRAINT Order_Details_ibfk_1 FOREIGN KEY (id_order) REFERENCES orders (id_order) ON DELETE NO ACTION ON UPDATE NO ACTION; CREATE TABLE IF NOT EXISTS learning_packs ( id_lp int(10) unsigned NOT NULL AUTO_INCREMENT, id_author int(10) unsigned NOT NULL DEFAULT '0', PRIMARY KEY (id_lp), KEY Learning_Packs_FKIndex2 (id_author), KEY id_lp (id_lp) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=23 ; CREATE TABLE IF NOT EXISTS tags ( id_tag int(10) unsigned NOT NULL AUTO_INCREMENT, tag varchar(255) DEFAULT NULL, PRIMARY KEY (id_tag), UNIQUE KEY tag (tag), KEY id_tag (id_tag), KEY tag_2 (tag), KEY tag_3 (tag) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3419 ; CREATE TABLE IF NOT EXISTS tutors_tag_relations ( id_tag int(10) unsigned NOT NULL DEFAULT '0', id_tutor int(10) DEFAULT NULL, KEY Tutors_Tag_Relations (id_tag), KEY id_tutor (id_tutor), KEY id_tag (id_tag) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; ALTER TABLE tutors_tag_relations ADD CONSTRAINT Tutors_Tag_Relations_ibfk_1 FOREIGN KEY (id_tag) REFERENCES tags (id_tag) ON DELETE NO ACTION ON UPDATE NO ACTION; CREATE TABLE IF NOT EXISTS learning_packs_tag_relations ( id_tag int(10) unsigned NOT NULL DEFAULT '0', id_tutor int(10) DEFAULT NULL, id_lp int(10) unsigned DEFAULT NULL, KEY Learning_Packs_Tag_Relations_FKIndex1 (id_tag), KEY id_lp (id_lp), KEY id_tag (id_tag) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; ALTER TABLE learning_packs_tag_relations ADD CONSTRAINT Learning_Packs_Tag_Relations_ibfk_1 FOREIGN KEY (id_tag) REFERENCES tags (id_tag) ON DELETE NO ACTION ON UPDATE NO ACTION; =================================================================================== Following is the exact query (this includes classes also - tutors can create classes and search terms are matched with classes created by tutors):- select count(distinct(od.id_od)) as tutor_popularity, CASE WHEN (IF((wc.id_wc 0), ( wc.wc_api_status = 1 AND wc.wc_type = 0 AND wc.class_date '2010-06-01 22:00:56' AND wccp.status = 1 AND (wccp.country_code='IE' or wccp.country_code IN ('INT'))), 0)) THEN 1 ELSE 0 END as 'classes_published', CASE WHEN (IF((lp.id_lp 0), (lp.id_status = 1 AND lp.published = 1 AND lpcp.status = 1 AND (lpcp.country_code='IE' or lpcp.country_code IN ('INT'))),0)) THEN 1 ELSE 0 END as 'packs_published', td . * , u . * from Tutor_Details AS td JOIN Users as u on u.id_user = td.id_user LEFT JOIN Learning_Packs_Tag_Relations AS lptagrels ON td.id_tutor = lptagrels.id_tutor LEFT JOIN Learning_Packs AS lp ON lptagrels.id_lp = lp.id_lp LEFT JOIN Learning_Packs_Categories AS lpc ON lpc.id_lp_cat = lp.id_lp_cat LEFT JOIN Learning_Packs_Categories AS lpcp ON lpcp.id_lp_cat = lpc.id_parent LEFT JOIN Learning_Pack_Content as lpct on (lp.id_lp = lpct.id_lp) LEFT JOIN Webclasses_Tag_Relations AS wtagrels ON td.id_tutor = wtagrels.id_tutor LEFT JOIN WebClasses AS wc ON wtagrels.id_wc = wc.id_wc LEFT JOIN Learning_Packs_Categories AS wcc ON wcc.id_lp_cat = wc.id_wp_cat LEFT JOIN Learning_Packs_Categories AS wccp ON wccp.id_lp_cat = wcc.id_parent LEFT JOIN Order_Details as od on td.id_tutor = od.id_author LEFT JOIN Orders as o on od.id_order = o.id_order LEFT JOIN Tutors_Tag_Relations as ttagrels ON td.id_tutor = ttagrels.id_tutor JOIN Tags as t on (t.id_tag = ttagrels.id_tag) OR (t.id_tag = lptagrels.id_tag) OR (t.id_tag = wtagrels.id_tag) where (u.country='IE' or u.country IN ('INT')) AND CASE WHEN ((t.id_tag = lptagrels.id_tag) AND (lp.id_lp 0)) THEN lp.id_status = 1 AND lp.published = 1 AND lpcp.status = 1 AND (lpcp.country_code='IE' or lpcp.country_code IN ('INT')) ELSE 1 END AND CASE WHEN ((t.id_tag = wtagrels.id_tag) AND (wc.id_wc 0)) THEN wc.wc_api_status = 1 AND wc.wc_type = 0 AND wc.class_date '2010-06-01 22:00:56' AND wccp.status = 1 AND (wccp.country_code='IE' or wccp.country_code IN ('INT')) ELSE 1 END AND CASE WHEN (od.id_od0) THEN od.id_author = td.id_tutor and o.order_status = 'paid' and CASE WHEN (od.id_wc 0) THEN od.can_attend_class=1 ELSE 1 END ELSE 1 END AND 1 group by td.id_tutor order by tutor_popularity desc, u.surname asc, u.name asc limit 0,20 Please note - The provided database structure does not show all the fields and tables as in this query

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• Suggestions for duplicate file finder algorithm (using C)

  - by Andrei Ciobanu

  Hello, I wanted to write a program that test if two files are duplicates (have exactly the same content). First I test if the files have the same sizes, and if they have i start to compare their contents. My first idea, was to "split" the files into fixed size blocks, then start a thread for every block, fseek to startup character of every block and continue the comparisons in parallel. When a comparison from a thread fails, the other working threads are canceled, and the program exits out of the thread spawning loop. The code looks like this: dupf.h #ifndef __NM__DUPF__H__ #define __NM__DUPF__H__ #define NUM_THREADS 15 #define BLOCK_SIZE 8192 /* Thread argument structure */ struct thread_arg_s { const char *name_f1; /* First file name */ const char *name_f2; /* Second file name */ int cursor; /* Where to seek in the file */ }; typedef struct thread_arg_s thread_arg; /** * 'arg' is of type thread_arg. * Checks if the specified file blocks are * duplicates. */ void *check_block_dup(void *arg); /** * Checks if two files are duplicates */ int check_dup(const char *name_f1, const char *name_f2); /** * Returns a valid pointer to a file. * If the file (given by the path/name 'fname') cannot be opened * in 'mode', the program is interrupted an error message is shown. **/ FILE *safe_fopen(const char *name, const char *mode); #endif dupf.c #include <errno.h> #include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include "dupf.h" FILE *safe_fopen(const char *fname, const char *mode) { FILE *f = NULL; f = fopen(fname, mode); if (f == NULL) { char emsg[255]; sprintf(emsg, "FOPEN() %s\t", fname); perror(emsg); exit(-1); } return (f); } void *check_block_dup(void *arg) { const char *name_f1 = NULL, *name_f2 = NULL; /* File names */ FILE *f1 = NULL, *f2 = NULL; /* Streams */ int cursor = 0; /* Reading cursor */ char buff_f1[BLOCK_SIZE], buff_f2[BLOCK_SIZE]; /* Character buffers */ int rchars_1, rchars_2; /* Readed characters */ /* Initializing variables from 'arg' */ name_f1 = ((thread_arg*)arg)->name_f1; name_f2 = ((thread_arg*)arg)->name_f2; cursor = ((thread_arg*)arg)->cursor; /* Opening files */ f1 = safe_fopen(name_f1, "r"); f2 = safe_fopen(name_f2, "r"); /* Setup cursor in files */ fseek(f1, cursor, SEEK_SET); fseek(f2, cursor, SEEK_SET); /* Initialize buffers */ rchars_1 = fread(buff_f1, 1, BLOCK_SIZE, f1); rchars_2 = fread(buff_f2, 1, BLOCK_SIZE, f2); if (rchars_1 != rchars_2) { /* fread failed to read the same portion. * program cannot continue */ perror("ERROR WHEN READING BLOCK"); exit(-1); } while (rchars_1-->0) { if (buff_f1[rchars_1] != buff_f2[rchars_1]) { /* Different characters */ fclose(f1); fclose(f2); pthread_exit("notdup"); } } /* Close streams */ fclose(f1); fclose(f2); pthread_exit("dup"); } int check_dup(const char *name_f1, const char *name_f2) { int num_blocks = 0; /* Number of 'blocks' to check */ int num_tsp = 0; /* Number of threads spawns */ int tsp_iter = 0; /* Iterator for threads spawns */ pthread_t *tsp_threads = NULL; thread_arg *tsp_threads_args = NULL; int tsp_threads_iter = 0; int thread_c_res = 0; /* Thread creation result */ int thread_j_res = 0; /* Thread join res */ int loop_res = 0; /* Function result */ int cursor; struct stat buf_f1; struct stat buf_f2; if (name_f1 == NULL || name_f2 == NULL) { /* Invalid input parameters */ perror("INVALID FNAMES\t"); return (-1); } if (stat(name_f1, &buf_f1) != 0 || stat(name_f2, &buf_f2) != 0) { /* Stat fails */ char emsg[255]; sprintf(emsg, "STAT() ERROR: %s %s\t", name_f1, name_f2); perror(emsg); return (-1); } if (buf_f1.st_size != buf_f2.st_size) { /* File have different sizes */ return (1); } /* Files have the same size, function exec. is continued */ num_blocks = (buf_f1.st_size / BLOCK_SIZE) + 1; num_tsp = (num_blocks / NUM_THREADS) + 1; cursor = 0; for (tsp_iter = 0; tsp_iter < num_tsp; tsp_iter++) { loop_res = 0; /* Create threads array for this spawn */ tsp_threads = malloc(NUM_THREADS * sizeof(*tsp_threads)); if (tsp_threads == NULL) { perror("TSP_THREADS ALLOC FAILURE\t"); return (-1); } /* Create arguments for every thread in the current spawn */ tsp_threads_args = malloc(NUM_THREADS * sizeof(*tsp_threads_args)); if (tsp_threads_args == NULL) { perror("TSP THREADS ARGS ALLOCA FAILURE\t"); return (-1); } /* Initialize arguments and create threads */ for (tsp_threads_iter = 0; tsp_threads_iter < NUM_THREADS; tsp_threads_iter++) { if (cursor >= buf_f1.st_size) { break; } tsp_threads_args[tsp_threads_iter].name_f1 = name_f1; tsp_threads_args[tsp_threads_iter].name_f2 = name_f2; tsp_threads_args[tsp_threads_iter].cursor = cursor; thread_c_res = pthread_create( &tsp_threads[tsp_threads_iter], NULL, check_block_dup, (void*)&tsp_threads_args[tsp_threads_iter]); if (thread_c_res != 0) { perror("THREAD CREATION FAILURE"); return (-1); } cursor+=BLOCK_SIZE; } /* Join last threads and get their status */ while (tsp_threads_iter-->0) { void *thread_res = NULL; thread_j_res = pthread_join(tsp_threads[tsp_threads_iter], &thread_res); if (thread_j_res != 0) { perror("THREAD JOIN FAILURE"); return (-1); } if (strcmp((char*)thread_res, "notdup")==0) { loop_res++; /* Closing other threads and exiting by condition * from loop. */ while (tsp_threads_iter-->0) { pthread_cancel(tsp_threads[tsp_threads_iter]); } } } free(tsp_threads); free(tsp_threads_args); if (loop_res > 0) { break; } } return (loop_res > 0) ? 1 : 0; } The function works fine (at least for what I've tested). Still, some guys from #C (freenode) suggested that the solution is overly complicated, and it may perform poorly because of parallel reading on hddisk. What I want to know: Is the threaded approach flawed by default ? Is fseek() so slow ? Is there a way to somehow map the files to memory and then compare them ?

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• Implementing a robust async stream reader for a console

  - by Jon

  I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. Edit: There are comments below correctly stating that since the data is coming from a stream, there is absolutely nothing that the receiver can infer about the structure of the data unless it is fully prepared to parse it. What I am trying to do here is leverage the "flush the output" "structure" that the owner of the console imparts while writing on it. I am prepared to assume (better: allow my caller to have the option to assume) that the OS will pass me the data written between two flushes of the stream in exactly one piece. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

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• Session is working in Localhost Properly but not Online (Cpanel)

  - by nando pandi

  Hello guys Sorry for my stupid question regarding to my yesterday question its not solved yet even the advice you have given but still not working. i have removed all of spaces but still showing the problem for me. it's working perfect in localhost but not in CPANEL. Here is the errors which give: Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/scalepro/public_html/Admin Panel/Remote Employee/main.php:1) in /home/scalepro/public_html/Admin Panel/Remote Employee/main.php on line 1 Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/scalepro/public_html/Admin Panel/Remote Employee/main.php:1) in /home/scalepro/public_html/Admin Panel/Remote Employee/main.php on line 1 Warning: Cannot modify header information - headers already sent by (output started at /home/scalepro/public_html/Admin Panel/Remote Employee/main.php:1) in /home/scalepro/public_html/Admin Panel/Remote Employee/main.php on line 13 Warning: Unknown: Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively in Unknown on line 0 ANY ONE PLEASE ??? Here is my code: <?php session_start(); require_once('../../Admin Panel/db.php'); if(isset($_POST['email']) && !empty($_POST['email']) && isset($_POST['password']) && !empty($_POST['password'])) { $email = $_POST['email']; $password = $_POST['password']; $query="SELECT RemoteEmployeeFullName, RemoteEmployeeEmail, RemoteEmployeePassword FROM remoteemployees WHERE RemoteEmployeeEmail='".$email."' AND RemoteEmployeePassword='".$password."'"; $queryrun=$connection->query($query); if($queryrun->num_rows > 0) { $_SESSION['email']=$RemoteEmployeeFullName; header("Location: /home/scalepro/public_html/Admin Panel/Remote Employee/REPLists.php"); } else { echo 'Email: <b>'.$email. '</b> or Password <b>'. $password.'</b> Is Not Typed Correctly Try Again Please!.'; header( "refresh:5;url= /home/scalepro/public_html/spd/myaccount.php" ); } } else { header( "refresh:5;url= /home/scalepro/public_html/spd/myaccount.php" ); } ?> if the condition gets true this will be redirected to a page by the name of REPLists.php here is the page. <?php session_start(); require_once('../../Admin Panel/db.php'); ?> <html> <head> <style> .wrapper { width:1250px; height:auto; border:solid 1px #000; margin:0 auto; padding:5px; border-radius:5px; -webkit-border-radius:5px; -moz-border-radius:5px; -ms-border-radius:5px; } .wrapper .header { width:1250px; height:20px; border-bottom:solid 1px #f0eeee; margin:auto 0; margin-bottom:12px; } .wrapper .header div { text-decoration:none; color:#F60; } .wrapper .header div a { text-decoration:none; color:#F60; } .wrapper .Labelcon { width:1250px; height:29px; border-bottom:solid 1px #ccc; } .wrapper .Labelcon .Label { width:125px; height:20px; float:left; text-align:center; border-left:1px solid #f0eeee; font:Verdana, Geneva, sans-serif; font-size:14.3px; font-weight:bold; } .wrapper .Valuecon { width:1250px; height:29px; border-bottom:solid 1px #ccc; color:#F60; text-decoration:none; } .wrapper .Valuecon .Value { width:125px; height:20px; float:left; text-align:center; border-left:1px solid #f0eeee; font-size:14px; } </style> </head> <body> <div class="wrapper"> <div class="header"> <div style="float:left;"><font color="#000000">Email: </font> <?php if(isset($_SESSION['email'])) { echo $_SESSION['email']; } ?> </div> <div style="float:right;"> <a href="#">My Profile</a> | <a href="logout.php">Logout</a></div> </div> <div class="Labelcon"> <div class="Label">Property ID</div> <div class="Label">Property Type</div> <div class="Label">Property Deal Type</div> <div class="Label">Property Owner</div> <div class="Label">Proposted Price</div> </div> <?php if(!isset($_SESSION['email'])) { header('Location:../../spd/myaccount.php'); } else { $query = "SELECT properties.PropertyID, properties.PropertyType, properties.PropertyDealType, properties.Status, properties.PropostedPrice, remoteemployees.RemoteEmployeeFullName, propertyowners.PropertyOwnerName, propertydealers.PropertyDealerName FROM remoteemployees, propertyowners, propertydealers, properties WHERE properties.PropertyOwnerID=propertyowners.PropertyOwnerID AND properties.PropertyDealerID=propertydealers.PropertyDealerID AND remoteemployees.RemoteEmployeeID=properties.RemoteEmployeeID ORDER BY properties.PropertyID "; $query_run = $connection->query($query); if( $connection->error ) exit( $connection->error ); while($row=$query_run->fetch_assoc()) { ?> <div class="Valuecon"> <div class="Value"><?php echo $row['PropertyID'] ?></div> <div class="Value"><?php echo $row['PropertyType'] ?></div> <div class="Value"><?php echo $row['PropertyDealType']?></div> <div class="Value"><?php echo $row['PropertyOwnerName'] ?></div> <div class="Value"><?php echo $row['PropostedPrice'];?></div> </div> <?php } }?> </div> </body> </html>

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• Array structure returned by Yii's model

  - by user1104955

  I am a Yii beginner and am running into a bit of a wall and hope someone will be able to help me get back onto track. I think this might be a fairly straight forward question to the seasoned Yii user. So here goes... In the controller, let's say I run the following call to the model- $variable = Post::model()->findAll(); All works fine and I pass the variable into the view. Here's where I get pretty stuck. The array that is returned in the above query is far more complex than I anticipated and I'm struggling to make sense of it. Here's a sample- print_r($variable); gives- Array ( [0] => Post Object ( [_md:CActiveRecord:private] => CActiveRecordMetaData Object ( [tableSchema] => CMysqlTableSchema Object ( [schemaName] => [name] => tbl_post [rawName] => `tbl_post` [primaryKey] => id [sequenceName] => [foreignKeys] => Array ( ) [columns] => Array ( [id] => CMysqlColumnSchema Object ( [name] => id [rawName] => `id` [allowNull] => [dbType] => int(11) [type] => integer [defaultValue] => [size] => 11 [precision] => 11 [scale] => [isPrimaryKey] => 1 [isForeignKey] => [autoIncrement] => 1 [_e:CComponent:private] => [_m:CComponent:private] => ) [post] => CMysqlColumnSchema Object ( [name] => post [rawName] => `post` [allowNull] => [dbType] => text [type] => string [defaultValue] => [size] => [precision] => [scale] => [isPrimaryKey] => [isForeignKey] => [autoIncrement] => [_e:CComponent:private] => [_m:CComponent:private] => ) ) [_e:CComponent:private] => [_m:CComponent:private] => ) [columns] => Array ( [id] => CMysqlColumnSchema Object ( [name] => id [rawName] => `id` [allowNull] => [dbType] => int(11) [type] => integer [defaultValue] => [size] => 11 [precision] => 11 [scale] => [isPrimaryKey] => 1 [isForeignKey] => [autoIncrement] => 1 [_e:CComponent:private] => [_m:CComponent:private] => ) [post] => CMysqlColumnSchema Object ( [name] => post [rawName] => `post` [allowNull] => [dbType] => text [type] => string [defaultValue] => [size] => [precision] => [scale] => [isPrimaryKey] => [isForeignKey] => [autoIncrement] => [_e:CComponent:private] => [_m:CComponent:private] => ) ) [relations] => Array ( [responses] => CHasManyRelation Object ( [limit] => -1 [offset] => -1 [index] => [through] => [joinType] => LEFT OUTER JOIN [on] => [alias] => [with] => Array ( ) [together] => [scopes] => [name] => responses [className] => Response [foreignKey] => post_id [select] => * [condition] => [params] => Array ( ) [group] => [join] => [having] => [order] => [_e:CComponent:private] => [_m:CComponent:private] => ) ) [attributeDefaults] => Array ( ) [_model:CActiveRecordMetaData:private] => Post Object ( [_md:CActiveRecord:private] => CActiveRecordMetaData Object *RECURSION* [_new:CActiveRecord:private] => [_attributes:CActiveRecord:private] => Array ( ) [_related:CActiveRecord:private] => Array ( ) [_c:CActiveRecord:private] => [_pk:CActiveRecord:private] => [_alias:CActiveRecord:private] => t [_errors:CModel:private] => Array ( ) [_validators:CModel:private] => [_scenario:CModel:private] => [_e:CComponent:private] => [_m:CComponent:private] => ) ) [_new:CActiveRecord:private] => [_attributes:CActiveRecord:private] => Array ( [id] => 1 [post] => User Post ) [_related:CActiveRecord:private] => Array ( ) [_c:CActiveRecord:private] => [_pk:CActiveRecord:private] => 1 [_alias:CActiveRecord:private] => t [_errors:CModel:private] => Array ( ) [_validators:CModel:private] => [_scenario:CModel:private] => update [_e:CComponent:private] => [_m:CComponent:private] => ) ) [sorry if there's an easier way to show this array, I'm not aware of it] Can anyone explain to me why the model returns such a complex array? It doesn't seem to matter what tables or columns or relations are used in your application, they all seem to me to return this format. Also, can someone explain the structure to me so that I can isolate the variables that I want to recover? Many thanks in advance, Nick

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• Cisco SR520w FE - WAN Port Stops Working

  - by Mike Hanley

  I have setup a Cisco SR520W and everything appears to be working. After about 1-2 days, it looks like the WAN port stops forwarding traffic to the Internet gateway IP of the device. If I unplug and then plug in the network cable connecting the WAN port of the SR520W to my Comcast Cable Modem, traffic startings flowing again. Also, if I restart the SR520W, the traffic will flow again. Any ideas? Here is the running config: Current configuration : 10559 bytes ! version 12.4 no service pad no service timestamps debug uptime service timestamps log datetime msec no service password-encryption ! hostname hostname.mydomain.com ! boot-start-marker boot-end-marker ! logging message-counter syslog no logging rate-limit enable secret 5 <removed> ! aaa new-model ! ! aaa authentication login default local aaa authorization exec default local ! ! aaa session-id common clock timezone PST -8 clock summer-time PDT recurring ! crypto pki trustpoint TP-self-signed-334750407 enrollment selfsigned subject-name cn=IOS-Self-Signed-Certificate-334750407 revocation-check none rsakeypair TP-self-signed-334750407 ! ! crypto pki certificate chain TP-self-signed-334750407 certificate self-signed 01 <removed> quit dot11 syslog ! dot11 ssid <removed> vlan 75 authentication open authentication key-management wpa guest-mode wpa-psk ascii 0 <removed> ! ip source-route ! ! ip dhcp excluded-address 172.16.0.1 172.16.0.10 ! ip dhcp pool inside import all network 172.16.0.0 255.240.0.0 default-router 172.16.0.1 dns-server 10.0.0.15 10.0.0.12 domain-name mydomain.com ! ! ip cef ip domain name mydomain.com ip name-server 68.87.76.178 ip name-server 66.240.48.9 ip port-map user-ezvpn-remote port udp 10000 ip ips notify SDEE ip ips name sdm_ips_rule ! ip ips signature-category category all retired true category ios_ips basic retired false ! ip inspect log drop-pkt no ipv6 cef ! multilink bundle-name authenticated parameter-map type inspect z1-z2-pmap audit-trail on password encryption aes ! ! username admin privilege 15 secret 5 <removed> ! crypto key pubkey-chain rsa named-key realm-cisco.pub key-string <removed> quit ! ! ! ! ! ! crypto ipsec client ezvpn EZVPN_REMOTE_CONNECTION_1 connect auto group EZVPN_GROUP_1 key <removed> mode client peer 64.1.208.90 virtual-interface 1 username admin password <removed> xauth userid mode local ! ! archive log config logging enable logging size 600 hidekeys ! ! ! class-map type inspect match-any SDM_AH match access-group name SDM_AH class-map type inspect match-any SDM-Voice-permit match protocol sip class-map type inspect match-any SDM_ESP match access-group name SDM_ESP class-map type inspect match-any SDM_EASY_VPN_REMOTE_TRAFFIC match protocol isakmp match protocol ipsec-msft match class-map SDM_AH match class-map SDM_ESP match protocol user-ezvpn-remote class-map type inspect match-all SDM_EASY_VPN_REMOTE_PT match class-map SDM_EASY_VPN_REMOTE_TRAFFIC match access-group 101 class-map type inspect match-any Easy_VPN_Remote_VT match access-group 102 class-map type inspect match-any sdm-cls-icmp-access match protocol icmp match protocol tcp match protocol udp class-map type inspect match-any sdm-cls-insp-traffic match protocol cuseeme match protocol dns match protocol ftp match protocol h323 match protocol https match protocol icmp match protocol imap match protocol pop3 match protocol netshow match protocol shell match protocol realmedia match protocol rtsp match protocol smtp extended match protocol sql-net match protocol streamworks match protocol tftp match protocol vdolive match protocol tcp match protocol udp class-map type inspect match-any L4-inspect-class match protocol icmp class-map type inspect match-all sdm-invalid-src match access-group 100 class-map type inspect match-all dhcp_out_self match access-group name dhcp-resp-permit class-map type inspect match-all dhcp_self_out match access-group name dhcp-req-permit class-map type inspect match-all sdm-protocol-http match protocol http ! ! policy-map type inspect sdm-permit-icmpreply class type inspect dhcp_self_out pass class type inspect sdm-cls-icmp-access inspect class class-default pass policy-map type inspect sdm-permit_VT class type inspect Easy_VPN_Remote_VT pass class class-default drop policy-map type inspect sdm-inspect class type inspect SDM-Voice-permit pass class type inspect sdm-cls-insp-traffic inspect class type inspect sdm-invalid-src drop log class type inspect sdm-protocol-http inspect z1-z2-pmap class class-default pass policy-map type inspect sdm-inspect-voip-in class type inspect SDM-Voice-permit pass class class-default drop policy-map type inspect sdm-permit class type inspect SDM_EASY_VPN_REMOTE_PT pass class type inspect dhcp_out_self pass class class-default drop ! zone security ezvpn-zone zone security out-zone zone security in-zone zone-pair security sdm-zp-in-ezvpn1 source in-zone destination ezvpn-zone service-policy type inspect sdm-permit_VT zone-pair security sdm-zp-out-ezpn1 source out-zone destination ezvpn-zone service-policy type inspect sdm-permit_VT zone-pair security sdm-zp-ezvpn-out1 source ezvpn-zone destination out-zone service-policy type inspect sdm-permit_VT zone-pair security sdm-zp-self-out source self destination out-zone service-policy type inspect sdm-permit-icmpreply zone-pair security sdm-zp-out-in source out-zone destination in-zone service-policy type inspect sdm-inspect-voip-in zone-pair security sdm-zp-ezvpn-in1 source ezvpn-zone destination in-zone service-policy type inspect sdm-permit_VT zone-pair security sdm-zp-out-self source out-zone destination self service-policy type inspect sdm-permit zone-pair security sdm-zp-in-out source in-zone destination out-zone service-policy type inspect sdm-inspect ! bridge irb ! ! interface FastEthernet0 switchport access vlan 75 ! interface FastEthernet1 switchport access vlan 75 ! interface FastEthernet2 switchport access vlan 75 ! interface FastEthernet3 switchport access vlan 75 ! interface FastEthernet4 description $FW_OUTSIDE$ ip address 75.149.48.76 255.255.255.240 ip nat outside ip ips sdm_ips_rule out ip virtual-reassembly zone-member security out-zone duplex auto speed auto crypto ipsec client ezvpn EZVPN_REMOTE_CONNECTION_1 ! interface Virtual-Template1 type tunnel no ip address ip virtual-reassembly zone-member security ezvpn-zone tunnel mode ipsec ipv4 ! interface Dot11Radio0 no ip address ! encryption vlan 75 mode ciphers aes-ccm ! ssid <removed> ! speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0 54.0 station-role root ! interface Dot11Radio0.75 encapsulation dot1Q 75 native ip virtual-reassembly bridge-group 75 bridge-group 75 subscriber-loop-control bridge-group 75 spanning-disabled bridge-group 75 block-unknown-source no bridge-group 75 source-learning no bridge-group 75 unicast-flooding ! interface Vlan1 no ip address ip virtual-reassembly bridge-group 1 ! interface Vlan75 no ip address ip virtual-reassembly bridge-group 75 bridge-group 75 spanning-disabled ! interface BVI1 no ip address ip nat inside ip virtual-reassembly ! interface BVI75 description $FW_INSIDE$ ip address 172.16.0.1 255.240.0.0 ip nat inside ip ips sdm_ips_rule in ip virtual-reassembly zone-member security in-zone crypto ipsec client ezvpn EZVPN_REMOTE_CONNECTION_1 inside ! ip forward-protocol nd ip route 0.0.0.0 0.0.0.0 75.149.48.78 2 ! ip http server ip http authentication local ip http secure-server ip http timeout-policy idle 60 life 86400 requests 10000 ip nat inside source list 1 interface FastEthernet4 overload ! ip access-list extended SDM_AH remark SDM_ACL Category=1 permit ahp any any ip access-list extended SDM_ESP remark SDM_ACL Category=1 permit esp any any ip access-list extended dhcp-req-permit remark SDM_ACL Category=1 permit udp any eq bootpc any eq bootps ip access-list extended dhcp-resp-permit remark SDM_ACL Category=1 permit udp any eq bootps any eq bootpc ! access-list 1 remark SDM_ACL Category=2 access-list 1 permit 172.16.0.0 0.15.255.255 access-list 100 remark SDM_ACL Category=128 access-list 100 permit ip host 255.255.255.255 any access-list 100 permit ip 127.0.0.0 0.255.255.255 any access-list 100 permit ip 75.149.48.64 0.0.0.15 any access-list 101 remark SDM_ACL Category=128 access-list 101 permit ip host 64.1.208.90 any access-list 102 remark SDM_ACL Category=1 access-list 102 permit ip any any ! ! ! ! snmp-server community <removed> RO ! control-plane ! bridge 1 protocol ieee bridge 1 route ip bridge 75 route ip banner login ^CSR520 Base Config - MFG 1.0 ^C ! line con 0 no modem enable line aux 0 line vty 0 4 transport input telnet ssh ! scheduler max-task-time 5000 end I also ran some diagnostics when the WAN port stopped working: 1. show interface fa4 FastEthernet4 is up, line protocol is up Hardware is PQUICC_FEC, address is 0026.99c5.b434 (bia 0026.99c5.b434) Description: $FW_OUTSIDE$ Internet address is 75.149.48.76/28 MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input 01:08:15, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/23/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 1000 bits/sec, 0 packets/sec 336446 packets input, 455403158 bytes Received 23 broadcasts, 0 runts, 0 giants, 37 throttles 41 input errors, 0 CRC, 0 frame, 0 overrun, 41 ignored 0 watchdog 0 input packets with dribble condition detected 172529 packets output, 23580132 bytes, 0 underruns 0 output errors, 0 collisions, 2 interface resets 0 unknown protocol drops 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out 2. show ip route Gateway of last resort is 75.149.48.78 to network 0.0.0.0 C 192.168.75.0/24 is directly connected, BVI75 64.0.0.0/32 is subnetted, 1 subnets S 64.1.208.90 [1/0] via 75.149.48.78 S 192.168.10.0/24 is directly connected, BVI75 75.0.0.0/28 is subnetted, 1 subnets C 75.149.48.64 is directly connected, FastEthernet4 S* 0.0.0.0/0 [2/0] via 75.149.48.78 3. show ip arp Protocol Address Age (min) Hardware Addr Type Interface Internet 75.149.48.65 69 001e.2a39.7b08 ARPA FastEthernet4 Internet 75.149.48.76 - 0026.99c5.b434 ARPA FastEthernet4 Internet 75.149.48.78 93 0022.2d6c.ae36 ARPA FastEthernet4 Internet 192.168.75.1 - 0027.0d58.f5f0 ARPA BVI75 Internet 192.168.75.12 50 7c6d.62c7.8c0a ARPA BVI75 Internet 192.168.75.13 0 001b.6301.1227 ARPA BVI75 4. sh ip cef Prefix Next Hop Interface 0.0.0.0/0 75.149.48.78 FastEthernet4 0.0.0.0/8 drop 0.0.0.0/32 receive 64.1.208.90/32 75.149.48.78 FastEthernet4 75.149.48.64/28 attached FastEthernet4 75.149.48.64/32 receive FastEthernet4 75.149.48.65/32 attached FastEthernet4 75.149.48.76/32 receive FastEthernet4 75.149.48.78/32 attached FastEthernet4 75.149.48.79/32 receive FastEthernet4 127.0.0.0/8 drop 192.168.10.0/24 attached BVI75 192.168.75.0/24 attached BVI75 192.168.75.0/32 receive BVI75 192.168.75.1/32 receive BVI75 192.168.75.12/32 attached BVI75 192.168.75.13/32 attached BVI75 192.168.75.255/32 receive BVI75 224.0.0.0/4 drop 224.0.0.0/24 receive 240.0.0.0/4 drop 255.255.255.255/32 receive Thanks in advance, -Mike

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• Upload File to Windows Azure Blob in Chunks through ASP.NET MVC, JavaScript and HTML5

  - by Shaun

  Originally posted on: http://geekswithblogs.net/shaunxu/archive/2013/07/01/upload-file-to-windows-azure-blob-in-chunks-through-asp.net.aspxMany people are using Windows Azure Blob Storage to store their data in the cloud. Blob storage provides 99.9% availability with easy-to-use API through .NET SDK and HTTP REST. For example, we can store JavaScript files, images, documents in blob storage when we are building an ASP.NET web application on a Web Role in Windows Azure. Or we can store our VHD files in blob and mount it as a hard drive in our cloud service. If you are familiar with Windows Azure, you should know that there are two kinds of blob: page blob and block blob. The page blob is optimized for random read and write, which is very useful when you need to store VHD files. The block blob is optimized for sequential/chunk read and write, which has more common usage. Since we can upload block blob in blocks through BlockBlob.PutBlock, and them commit them as a whole blob with invoking the BlockBlob.PutBlockList, it is very powerful to upload large files, as we can upload blocks in parallel, and provide pause-resume feature. There are many documents, articles and blog posts described on how to upload a block blob. Most of them are focus on the server side, which means when you had received a big file, stream or binaries, how to upload them into blob storage in blocks through .NET SDK.  But the problem is, how can we upload these large files from client side, for example, a browser. This questioned to me when I was working with a Chinese customer to help them build a network disk production on top of azure. The end users upload their files from the web portal, and then the files will be stored in blob storage from the Web Role. My goal is to find the best way to transform the file from client (end user’s machine) to the server (Web Role) through browser. In this post I will demonstrate and describe what I had done, to upload large file in chunks with high speed, and save them as blocks into Windows Azure Blob Storage.   Traditional Upload, Works with Limitation The simplest way to implement this requirement is to create a web page with a form that contains a file input element and a submit button. 1: @using (Html.BeginForm("About", "Index", FormMethod.Post, new { enctype = "multipart/form-data" })) 2: { 3: <input type="file" name="file" /> 4: <input type="submit" value="upload" /> 5: } And then in the backend controller, we retrieve the whole content of this file and upload it in to the blob storage through .NET SDK. We can split the file in blocks and upload them in parallel and commit. The code had been well blogged in the community. 1: [HttpPost] 2: public ActionResult About(HttpPostedFileBase file) 3: { 4: var container = _client.GetContainerReference("test"); 5: container.CreateIfNotExists(); 6: var blob = container.GetBlockBlobReference(file.FileName); 7: var blockDataList = new Dictionary<string, byte[]>(); 8: using (var stream = file.InputStream) 9: { 10: var blockSizeInKB = 1024; 11: var offset = 0; 12: var index = 0; 13: while (offset < stream.Length) 14: { 15: var readLength = Math.Min(1024 * blockSizeInKB, (int)stream.Length - offset); 16: var blockData = new byte[readLength]; 17: offset += stream.Read(blockData, 0, readLength); 18: blockDataList.Add(Convert.ToBase64String(BitConverter.GetBytes(index)), blockData); 19:  20: index++; 21: } 22: } 23:  24: Parallel.ForEach(blockDataList, (bi) => 25: { 26: blob.PutBlock(bi.Key, new MemoryStream(bi.Value), null); 27: }); 28: blob.PutBlockList(blockDataList.Select(b => b.Key).ToArray()); 29:  30: return RedirectToAction("About"); 31: } This works perfect if we selected an image, a music or a small video to upload. But if I selected a large file, let’s say a 6GB HD-movie, after upload for about few minutes the page will be shown as below and the upload will be terminated. In ASP.NET there is a limitation of request length and the maximized request length is defined in the web.config file. It’s a number which less than about 4GB. So if we want to upload a really big file, we cannot simply implement in this way. Also, in Windows Azure, a cloud service network load balancer will terminate the connection if exceed the timeout period. From my test the timeout looks like 2 - 3 minutes. Hence, when we need to upload a large file we cannot just use the basic HTML elements. Besides the limitation mentioned above, the simple HTML file upload cannot provide rich upload experience such as chunk upload, pause and pause-resume. So we need to find a better way to upload large file from the client to the server.   Upload in Chunks through HTML5 and JavaScript In order to break those limitation mentioned above we will try to upload the large file in chunks. This takes some benefit to us such as - No request size limitation: Since we upload in chunks, we can define the request size for each chunks regardless how big the entire file is. - No timeout problem: The size of chunks are controlled by us, which means we should be able to make sure request for each chunk upload will not exceed the timeout period of both ASP.NET and Windows Azure load balancer. It was a big challenge to upload big file in chunks until we have HTML5. There are some new features and improvements introduced in HTML5 and we will use them to implement our solution.   In HTML5, the File interface had been improved with a new method called “slice”. It can be used to read part of the file by specifying the start byte index and the end byte index. For example if the entire file was 1024 bytes, file.slice(512, 768) will read the part of this file from the 512nd byte to 768th byte, and return a new object of interface called "Blob”, which you can treat as an array of bytes. In fact,  a Blob object represents a file-like object of immutable, raw data. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system. For more information about the Blob please refer here. File and Blob is very useful to implement the chunk upload. We will use File interface to represent the file the user selected from the browser and then use File.slice to read the file in chunks in the size we wanted. For example, if we wanted to upload a 10MB file with 512KB chunks, then we can read it in 512KB blobs by using File.slice in a loop.   Assuming we have a web page as below. User can select a file, an input box to specify the block size in KB and a button to start upload. 1: <div> 2: <input type="file" id="upload_files" name="files[]" /><br /> 3: Block Size: <input type="number" id="block_size" value="512" name="block_size" />KB<br /> 4: <input type="button" id="upload_button_blob" name="upload" value="upload (blob)" /> 5: </div> Then we can have the JavaScript function to upload the file in chunks when user clicked the button. 1: <script type="text/javascript"> 1: 2: $(function () { 3: $("#upload_button_blob").click(function () { 4: }); 5: });</script> Firstly we need to ensure the client browser supports the interfaces we are going to use. Just try to invoke the File, Blob and FormData from the “window” object. If any of them is “undefined” the condition result will be “false” which means your browser doesn’t support these premium feature and it’s time for you to get your browser updated. FormData is another new feature we are going to use in the future. It could generate a temporary form for us. We will use this interface to create a form with chunk and associated metadata when invoked the service through ajax. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: if (window.File && window.Blob && window.FormData) { 4: alert("Your brwoser is awesome, let's rock!"); 5: } 6: else { 7: alert("Oh man plz update to a modern browser before try is cool stuff out."); 8: return; 9: } 10: }); Each browser supports these interfaces by their own implementation and currently the Blob, File and File.slice are supported by Chrome 21, FireFox 13, IE 10, Opera 12 and Safari 5.1 or higher. After that we worked on the files the user selected one by one since in HTML5, user can select multiple files in one file input box. 1: var files = $("#upload_files")[0].files; 2: for (var i = 0; i < files.length; i++) { 3: var file = files[i]; 4: var fileSize = file.size; 5: var fileName = file.name; 6: } Next, we calculated the start index and end index for each chunks based on the size the user specified from the browser. We put them into an array with the file name and the index, which will be used when we upload chunks into Windows Azure Blob Storage as blocks since we need to specify the target blob name and the block index. At the same time we will store the list of all indexes into another variant which will be used to commit blocks into blob in Azure Storage once all chunks had been uploaded successfully. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10:  11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: var blockSizeInKB = $("#block_size").val(); 14: var blockSize = blockSizeInKB * 1024; 15: var blocks = []; 16: var offset = 0; 17: var index = 0; 18: var list = ""; 19: while (offset < fileSize) { 20: var start = offset; 21: var end = Math.min(offset + blockSize, fileSize); 22:  23: blocks.push({ 24: name: fileName, 25: index: index, 26: start: start, 27: end: end 28: }); 29: list += index + ","; 30:  31: offset = end; 32: index++; 33: } 34: } 35: }); Now we have all chunks’ information ready. The next step should be upload them one by one to the server side, and at the server side when received a chunk it will upload as a block into Blob Storage, and finally commit them with the index list through BlockBlobClient.PutBlockList. But since all these invokes are ajax calling, which means not synchronized call. So we need to introduce a new JavaScript library to help us coordinate the asynchronize operation, which named “async.js”. You can download this JavaScript library here, and you can find the document here. I will not explain this library too much in this post. We will put all procedures we want to execute as a function array, and pass into the proper function defined in async.js to let it help us to control the execution sequence, in series or in parallel. Hence we will define an array and put the function for chunk upload into this array. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4:  5: // start to upload each files in chunks 6: var files = $("#upload_files")[0].files; 7: for (var i = 0; i < files.length; i++) { 8: var file = files[i]; 9: var fileSize = file.size; 10: var fileName = file.name; 11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: ... ... 14:  15: // define the function array and push all chunk upload operation into this array 16: blocks.forEach(function (block) { 17: putBlocks.push(function (callback) { 18: }); 19: }); 20: } 21: }); 22: }); As you can see, I used File.slice method to read each chunks based on the start and end byte index we calculated previously, and constructed a temporary HTML form with the file name, chunk index and chunk data through another new feature in HTML5 named FormData. Then post this form to the backend server through jQuery.ajax. This is the key part of our solution. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: blocks.forEach(function (block) { 15: putBlocks.push(function (callback) { 16: // load blob based on the start and end index for each chunks 17: var blob = file.slice(block.start, block.end); 18: // put the file name, index and blob into a temporary from 19: var fd = new FormData(); 20: fd.append("name", block.name); 21: fd.append("index", block.index); 22: fd.append("file", blob); 23: // post the form to backend service (asp.net mvc controller action) 24: $.ajax({ 25: url: "/Home/UploadInFormData", 26: data: fd, 27: processData: false, 28: contentType: "multipart/form-data", 29: type: "POST", 30: success: function (result) { 31: if (!result.success) { 32: alert(result.error); 33: } 34: callback(null, block.index); 35: } 36: }); 37: }); 38: }); 39: } 40: }); Then we will invoke these functions one by one by using the async.js. And once all functions had been executed successfully I invoked another ajax call to the backend service to commit all these chunks (blocks) as the blob in Windows Azure Storage. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.series(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); That’s all in the client side. The outline of our logic would be - Calculate the start and end byte index for each chunks based on the block size. - Defined the functions of reading the chunk form file and upload the content to the backend service through ajax. - Execute the functions defined in previous step with “async.js”. - Commit the chunks by invoking the backend service in Windows Azure Storage finally.   Save Chunks as Blocks into Blob Storage In above we finished the client size JavaScript code. It uploaded the file in chunks to the backend service which we are going to implement in this step. We will use ASP.NET MVC as our backend service, and it will receive the chunks, upload into Windows Azure Bob Storage in blocks, then finally commit as one blob. As in the client side we uploaded chunks by invoking the ajax call to the URL "/Home/UploadInFormData", I created a new action under the Index controller and it only accepts HTTP POST request. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: } 8: catch (Exception e) 9: { 10: error = e.ToString(); 11: } 12:  13: return new JsonResult() 14: { 15: Data = new 16: { 17: success = string.IsNullOrWhiteSpace(error), 18: error = error 19: } 20: }; 21: } Then I retrieved the file name, index and the chunk content from the Request.Form object, which was passed from our client side. And then, used the Windows Azure SDK to create a blob container (in this case we will use the container named “test”.) and create a blob reference with the blob name (same as the file name). Then uploaded the chunk as a block of this blob with the index, since in Blob Storage each block must have an index (ID) associated with so that finally we can put all blocks as one blob by specifying their block ID list. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var index = int.Parse(Request.Form["index"]); 9: var file = Request.Files[0]; 10: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 11:  12: var container = _client.GetContainerReference("test"); 13: container.CreateIfNotExists(); 14: var blob = container.GetBlockBlobReference(name); 15: blob.PutBlock(id, file.InputStream, null); 16: } 17: catch (Exception e) 18: { 19: error = e.ToString(); 20: } 21:  22: return new JsonResult() 23: { 24: Data = new 25: { 26: success = string.IsNullOrWhiteSpace(error), 27: error = error 28: } 29: }; 30: } Next, I created another action to commit the blocks into blob once all chunks had been uploaded. Similarly, I retrieved the blob name from the Request.Form. I also retrieved the chunks ID list, which is the block ID list from the Request.Form in a string format, split them as a list, then invoked the BlockBlob.PutBlockList method. After that our blob will be shown in the container and ready to be download. 1: [HttpPost] 2: public JsonResult Commit() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var list = Request.Form["list"]; 9: var ids = list 10: .Split(',') 11: .Where(id => !string.IsNullOrWhiteSpace(id)) 12: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 13: .ToArray(); 14:  15: var container = _client.GetContainerReference("test"); 16: container.CreateIfNotExists(); 17: var blob = container.GetBlockBlobReference(name); 18: blob.PutBlockList(ids); 19: } 20: catch (Exception e) 21: { 22: error = e.ToString(); 23: } 24:  25: return new JsonResult() 26: { 27: Data = new 28: { 29: success = string.IsNullOrWhiteSpace(error), 30: error = error 31: } 32: }; 33: } Now we finished all code we need. The whole process of uploading would be like this below. Below is the full client side JavaScript code. 1: <script type="text/javascript" src="~/Scripts/async.js"></script> 2: <script type="text/javascript"> 3: $(function () { 4: $("#upload_button_blob").click(function () { 5: // assert the browser support html5 6: if (window.File && window.Blob && window.FormData) { 7: alert("Your brwoser is awesome, let's rock!"); 8: } 9: else { 10: alert("Oh man plz update to a modern browser before try is cool stuff out."); 11: return; 12: } 13:  14: // start to upload each files in chunks 15: var files = $("#upload_files")[0].files; 16: for (var i = 0; i < files.length; i++) { 17: var file = files[i]; 18: var fileSize = file.size; 19: var fileName = file.name; 20:  21: // calculate the start and end byte index for each blocks(chunks) 22: // with the index, file name and index list for future using 23: var blockSizeInKB = $("#block_size").val(); 24: var blockSize = blockSizeInKB * 1024; 25: var blocks = []; 26: var offset = 0; 27: var index = 0; 28: var list = ""; 29: while (offset < fileSize) { 30: var start = offset; 31: var end = Math.min(offset + blockSize, fileSize); 32:  33: blocks.push({ 34: name: fileName, 35: index: index, 36: start: start, 37: end: end 38: }); 39: list += index + ","; 40:  41: offset = end; 42: index++; 43: } 44:  45: // define the function array and push all chunk upload operation into this array 46: var putBlocks = []; 47: blocks.forEach(function (block) { 48: putBlocks.push(function (callback) { 49: // load blob based on the start and end index for each chunks 50: var blob = file.slice(block.start, block.end); 51: // put the file name, index and blob into a temporary from 52: var fd = new FormData(); 53: fd.append("name", block.name); 54: fd.append("index", block.index); 55: fd.append("file", blob); 56: // post the form to backend service (asp.net mvc controller action) 57: $.ajax({ 58: url: "/Home/UploadInFormData", 59: data: fd, 60: processData: false, 61: contentType: "multipart/form-data", 62: type: "POST", 63: success: function (result) { 64: if (!result.success) { 65: alert(result.error); 66: } 67: callback(null, block.index); 68: } 69: }); 70: }); 71: }); 72:  73: // invoke the functions one by one 74: // then invoke the commit ajax call to put blocks into blob in azure storage 75: async.series(putBlocks, function (error, result) { 76: var data = { 77: name: fileName, 78: list: list 79: }; 80: $.post("/Home/Commit", data, function (result) { 81: if (!result.success) { 82: alert(result.error); 83: } 84: else { 85: alert("done!"); 86: } 87: }); 88: }); 89: } 90: }); 91: }); 92: </script> And below is the full ASP.NET MVC controller code. 1: public class HomeController : Controller 2: { 3: private CloudStorageAccount _account; 4: private CloudBlobClient _client; 5:  6: public HomeController() 7: : base() 8: { 9: _account = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("DataConnectionString")); 10: _client = _account.CreateCloudBlobClient(); 11: } 12:  13: public ActionResult Index() 14: { 15: ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application."; 16:  17: return View(); 18: } 19:  20: [HttpPost] 21: public JsonResult UploadInFormData() 22: { 23: var error = string.Empty; 24: try 25: { 26: var name = Request.Form["name"]; 27: var index = int.Parse(Request.Form["index"]); 28: var file = Request.Files[0]; 29: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 30:  31: var container = _client.GetContainerReference("test"); 32: container.CreateIfNotExists(); 33: var blob = container.GetBlockBlobReference(name); 34: blob.PutBlock(id, file.InputStream, null); 35: } 36: catch (Exception e) 37: { 38: error = e.ToString(); 39: } 40:  41: return new JsonResult() 42: { 43: Data = new 44: { 45: success = string.IsNullOrWhiteSpace(error), 46: error = error 47: } 48: }; 49: } 50:  51: [HttpPost] 52: public JsonResult Commit() 53: { 54: var error = string.Empty; 55: try 56: { 57: var name = Request.Form["name"]; 58: var list = Request.Form["list"]; 59: var ids = list 60: .Split(',') 61: .Where(id => !string.IsNullOrWhiteSpace(id)) 62: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 63: .ToArray(); 64:  65: var container = _client.GetContainerReference("test"); 66: container.CreateIfNotExists(); 67: var blob = container.GetBlockBlobReference(name); 68: blob.PutBlockList(ids); 69: } 70: catch (Exception e) 71: { 72: error = e.ToString(); 73: } 74:  75: return new JsonResult() 76: { 77: Data = new 78: { 79: success = string.IsNullOrWhiteSpace(error), 80: error = error 81: } 82: }; 83: } 84: } And if we selected a file from the browser we will see our application will upload chunks in the size we specified to the server through ajax call in background, and then commit all chunks in one blob. Then we can find the blob in our Windows Azure Blob Storage.   Optimized by Parallel Upload In previous example we just uploaded our file in chunks. This solved the problem that ASP.NET MVC request content size limitation as well as the Windows Azure load balancer timeout. But it might introduce the performance problem since we uploaded chunks in sequence. In order to improve the upload performance we could modify our client side code a bit to make the upload operation invoked in parallel. The good news is that, “async.js” library provides the parallel execution function. If you remembered the code we invoke the service to upload chunks, it utilized “async.series” which means all functions will be executed in sequence. Now we will change this code to “async.parallel”. This will invoke all functions in parallel. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallel(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); In this way all chunks will be uploaded to the server side at the same time to maximize the bandwidth usage. This should work if the file was not very large and the chunk size was not very small. But for large file this might introduce another problem that too many ajax calls are sent to the server at the same time. So the best solution should be, upload the chunks in parallel with maximum concurrency limitation. The code below specified the concurrency limitation to 4, which means at the most only 4 ajax calls could be invoked at the same time. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallelLimit(putBlocks, 4, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: });   Summary In this post we discussed how to upload files in chunks to the backend service and then upload them into Windows Azure Blob Storage in blocks. We focused on the frontend side and leverage three new feature introduced in HTML 5 which are - File.slice: Read part of the file by specifying the start and end byte index. - Blob: File-like interface which contains the part of the file content. - FormData: Temporary form element that we can pass the chunk alone with some metadata to the backend service. Then we discussed the performance consideration of chunk uploading. Sequence upload cannot provide maximized upload speed, but the unlimited parallel upload might crash the browser and server if too many chunks. So we finally came up with the solution to upload chunks in parallel with the concurrency limitation. We also demonstrated how to utilize “async.js” JavaScript library to help us control the asynchronize call and the parallel limitation.   Regarding the chunk size and the parallel limitation value there is no “best” value. You need to test vary composition and find out the best one for your particular scenario. It depends on the local bandwidth, client machine cores and the server side (Windows Azure Cloud Service Virtual Machine) cores, memory and bandwidth. Below is one of my performance test result. The client machine was Windows 8 IE 10 with 4 cores. I was using Microsoft Cooperation Network. The web site was hosted on Windows Azure China North data center (in Beijing) with one small web role (1.7GB 1 core CPU, 1.75GB memory with 100Mbps bandwidth). The test cases were - Chunk size: 512KB, 1MB, 2MB, 4MB. - Upload Mode: Sequence, parallel (unlimited), parallel with limit (4 threads, 8 threads). - Chunk Format: base64 string, binaries. - Target file: 100MB. - Each case was tested 3 times. Below is the test result chart. Some thoughts, but not guidance or best practice: - Parallel gets better performance than series. - No significant performance improvement between parallel 4 threads and 8 threads. - Transform with binaries provides better performance than base64. - In all cases, chunk size in 1MB - 2MB gets better performance.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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• AngularJS on top of ASP.NET: Moving the MVC framework out to the browser

  - by Varun Chatterji

  Heavily drawing inspiration from Ruby on Rails, MVC4’s convention over configuration model of development soon became the Holy Grail of .NET web development. The MVC model brought with it the goodness of proper separation of concerns between business logic, data, and the presentation logic. However, the MVC paradigm, was still one in which server side .NET code could be mixed with presentation code. The Razor templating engine, though cleaner than its predecessors, still encouraged and allowed you to mix .NET server side code with presentation logic. Thus, for example, if the developer required a certain <div> tag to be shown if a particular variable ShowDiv was true in the View’s model, the code could look like the following: Fig 1: To show a div or not. Server side .NET code is used in the View Mixing .NET code with HTML in views can soon get very messy. Wouldn’t it be nice if the presentation layer (HTML) could be pure HTML? Also, in the ASP.NET MVC model, some of the business logic invariably resides in the controller. It is tempting to use an anti­pattern like the one shown above to control whether a div should be shown or not. However, best practice would indicate that the Controller should not be aware of the div. The ShowDiv variable in the model should not exist. A controller should ideally, only be used to do the plumbing of getting the data populated in the model and nothing else. The view (ideally pure HTML) should render the presentation layer based on the model. In this article we will see how Angular JS, a new JavaScript framework by Google can be used effectively to build web applications where: 1. Views are pure HTML 2. Controllers (in the server sense) are pure REST based API calls 3. The presentation layer is loaded as needed from partial HTML only files. What is MVVM? MVVM short for Model View View Model is a new paradigm in web development. In this paradigm, the Model and View stuff exists on the client side through javascript instead of being processed on the server through postbacks. These frameworks are JavaScript frameworks that facilitate the clear separation of the “frontend” or the data rendering logic from the “backend” which is typically just a REST based API that loads and processes data through a resource model. The frameworks are called MVVM as a change to the Model (through javascript) gets reflected in the view immediately i.e. Model > View. Also, a change on the view (through manual input) gets reflected in the model immediately i.e. View > Model. The following figure shows this conceptually (comments are shown in red): Fig 2: Demonstration of MVVM in action In Fig 2, two text boxes are bound to the same variable model.myInt. Thus, changing the view manually (changing one text box through keyboard input) also changes the other textbox in real time demonstrating V > M property of a MVVM framework. Furthermore, clicking the button adds 1 to the value of model.myInt thus changing the model through JavaScript. This immediately updates the view (the value in the two textboxes) thus demonstrating the M > V property of a MVVM framework. Thus we see that the model in a MVVM JavaScript framework can be regarded as “the single source of truth“. This is an important concept. Angular is one such MVVM framework. We shall use it to build a simple app that sends SMS messages to a particular number. Application, Routes, Views, Controllers, Scope and Models Angular can be used in many ways to construct web applications. For this article, we shall only focus on building Single Page Applications (SPAs). Many of the approaches we will follow in this article have alternatives. It is beyond the scope of this article to explain every nuance in detail but we shall try to touch upon the basic concepts and end up with a working application that can be used to send SMS messages using Sent.ly Plus (a service that is itself built using Angular). Before you read on, we would like to urge you to forget what you know about Models, Views, Controllers and Routes in the ASP.NET MVC4 framework. All these words have different meanings in the Angular world. Whenever these words are used in this article, they will refer to Angular concepts and not ASP.NET MVC4 concepts. The following figure shows the skeleton of the root page of an SPA: Fig 3: The skeleton of a SPA The skeleton of the application is based on the Bootstrap starter template which can be found at: http://getbootstrap.com/examples/starter­template/ Apart from loading the Angular, jQuery and Bootstrap JavaScript libraries, it also loads our custom scripts /app/js/controllers.js /app/js/app.js These scripts define the routes, views and controllers which we shall come to in a moment. Application Notice that the body tag (Fig. 3) has an extra attribute: ng­app=”smsApp” Providing this tag “bootstraps” our single page application. It tells Angular to load a “module” called smsApp. This “module” is defined /app/js/app.js angular.module('smsApp', ['smsApp.controllers', function () {}]) Fig 4: The definition of our application module The line shows above, declares a module called smsApp. It also declares that this module “depends” on another module called “smsApp.controllers”. The smsApp.controllers module will contain all the controllers for our SPA. Routing and Views Notice that in the Navbar (in Fig 3) we have included two hyperlinks to: “#/app” “#/help” This is how Angular handles routing. Since the URLs start with “#”, they are actually just bookmarks (and not server side resources). However, our route definition (in /app/js/app.js) gives these URLs a special meaning within the Angular framework. angular.module('smsApp', ['smsApp.controllers', function () { }]) //Configure the routes .config(['$routeProvider', function ($routeProvider) { $routeProvider.when('/binding', { templateUrl: '/app/partials/bindingexample.html', controller: 'BindingController' }); }]); Fig 5: The definition of a route with an associated partial view and controller As we can see from the previous code sample, we are using the $routeProvider object in the configuration of our smsApp module. Notice how the code “asks for” the $routeProvider object by specifying it as a dependency in the [] braces and then defining a function that accepts it as a parameter. This is known as dependency injection. Please refer to the following link if you want to delve into this topic: http://docs.angularjs.org/guide/di What the above code snippet is doing is that it is telling Angular that when the URL is “#/binding”, then it should load the HTML snippet (“partial view”) found at /app/partials/bindingexample.html. Also, for this URL, Angular should load the controller called “BindingController”. We have also marked the div with the class “container” (in Fig 3) with the ng­view attribute. This attribute tells Angular that views (partial HTML pages) defined in the routes will be loaded within this div. You can see that the Angular JavaScript framework, unlike many other frameworks, works purely by extending HTML tags and attributes. It also allows you to extend HTML with your own tags and attributes (through directives) if you so desire, you can find out more about directives at the following URL: http://www.codeproject.com/Articles/607873/Extending­HTML­with­AngularJS­Directives Controllers and Models We have seen how we define what views and controllers should be loaded for a particular route. Let us now consider how controllers are defined. Our controllers are defined in the file /app/js/controllers.js. The following snippet shows the definition of the “BindingController” which is loaded when we hit the URL http://localhost:port/index.html#/binding (as we have defined in the route earlier as shown in Fig 5). Remember that we had defined that our application module “smsApp” depends on the “smsApp.controllers” module (see Fig 4). The code snippet below shows how the “BindingController” defined in the route shown in Fig 5 is defined in the module smsApp.controllers: angular.module('smsApp.controllers', [function () { }]) .controller('BindingController', ['$scope', function ($scope) { $scope.model = {}; $scope.model.myInt = 6; $scope.addOne = function () { $scope.model.myInt++; } }]); Fig 6: The definition of a controller in the “smsApp.controllers” module. The pieces are falling in place! Remember Fig.2? That was the code of a partial view that was loaded within the container div of the skeleton SPA shown in Fig 3. The route definition shown in Fig 5 also defined that the controller called “BindingController” (shown in Fig 6.) was loaded when we loaded the URL: http://localhost:22544/index.html#/binding The button in Fig 2 was marked with the attribute ng­click=”addOne()” which added 1 to the value of model.myInt. In Fig 6, we can see that this function is actually defined in the “BindingController”. Scope We can see from Fig 6, that in the definition of “BindingController”, we defined a dependency on $scope and then, as usual, defined a function which “asks for” $scope as per the dependency injection pattern. So what is $scope? Any guesses? As you might have guessed a scope is a particular “address space” where variables and functions may be defined. This has a similar meaning to scope in a programming language like C#. Model: The Scope is not the Model It is tempting to assign variables in the scope directly. For example, we could have defined myInt as $scope.myInt = 6 in Fig 6 instead of $scope.model.myInt = 6. The reason why this is a bad idea is that scope in hierarchical in Angular. Thus if we were to define a controller which was defined within the another controller (nested controllers), then the inner controller would inherit the scope of the parent controller. This inheritance would follow JavaScript prototypal inheritance. Let’s say the parent controller defined a variable through $scope.myInt = 6. The child controller would inherit the scope through java prototypical inheritance. This basically means that the child scope has a variable myInt that points to the parent scopes myInt variable. Now if we assigned the value of myInt in the parent, the child scope would be updated with the same value as the child scope’s myInt variable points to the parent scope’s myInt variable. However, if we were to assign the value of the myInt variable in the child scope, then the link of that variable to the parent scope would be broken as the variable myInt in the child scope now points to the value 6 and not to the parent scope’s myInt variable. But, if we defined a variable model in the parent scope, then the child scope will also have a variable model that points to the model variable in the parent scope. Updating the value of $scope.model.myInt in the parent scope would change the model variable in the child scope too as the variable is pointed to the model variable in the parent scope. Now changing the value of $scope.model.myInt in the child scope would ALSO change the value in the parent scope. This is because the model reference in the child scope is pointed to the scope variable in the parent. We did no new assignment to the model variable in the child scope. We only changed an attribute of the model variable. Since the model variable (in the child scope) points to the model variable in the parent scope, we have successfully changed the value of myInt in the parent scope. Thus the value of $scope.model.myInt in the parent scope becomes the “single source of truth“. This is a tricky concept, thus it is considered good practice to NOT use scope inheritance. More info on prototypal inheritance in Angular can be found in the “JavaScript Prototypal Inheritance” section at the following URL: https://github.com/angular/angular.js/wiki/Understanding­Scopes. Building It: An Angular JS application using a .NET Web API Backend Now that we have a perspective on the basic components of an MVVM application built using Angular, let’s build something useful. We will build an application that can be used to send out SMS messages to a given phone number. The following diagram describes the architecture of the application we are going to build: Fig 7: Broad application architecture We are going to add an HTML Partial to our project. This partial will contain the form fields that will accept the phone number and message that needs to be sent as an SMS. It will also display all the messages that have previously been sent. All the executable code that is run on the occurrence of events (button clicks etc.) in the view resides in the controller. The controller interacts with the ASP.NET WebAPI to get a history of SMS messages, add a message etc. through a REST based API. For the purposes of simplicity, we will use an in memory data structure for the purposes of creating this application. Thus, the tasks ahead of us are: Creating the REST WebApi with GET, PUT, POST, DELETE methods. Creating the SmsView.html partial Creating the SmsController controller with methods that are called from the SmsView.html partial Add a new route that loads the controller and the partial. 1. Creating the REST WebAPI This is a simple task that should be quite straightforward to any .NET developer. The following listing shows our ApiController: public class SmsMessage { public string to { get; set; } public string message { get; set; } } public class SmsResource : SmsMessage { public int smsId { get; set; } } public class SmsResourceController : ApiController { public static Dictionary<int, SmsResource> messages = new Dictionary<int, SmsResource>(); public static int currentId = 0; // GET api/<controller> public List<SmsResource> Get() { List<SmsResource> result = new List<SmsResource>(); foreach (int key in messages.Keys) { result.Add(messages[key]); } return result; } // GET api/<controller>/5 public SmsResource Get(int id) { if (messages.ContainsKey(id)) return messages[id]; return null; } // POST api/<controller> public List<SmsResource> Post([FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { SmsResource res = (SmsResource) value; res.smsId = currentId++; messages.Add(res.smsId, res); //SentlyPlusSmsSender.SendMessage(value.to, value.message); return Get(); } } // PUT api/<controller>/5 public List<SmsResource> Put(int id, [FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { if (messages.ContainsKey(id)) { //Update the message messages[id].message = value.message; messages[id].to = value.message; } return Get(); } } // DELETE api/<controller>/5 public List<SmsResource> Delete(int id) { if (messages.ContainsKey(id)) { messages.Remove(id); } return Get(); } } Once this class is defined, we should be able to access the WebAPI by a simple GET request using the browser: http://localhost:port/api/SmsResource Notice the commented line: //SentlyPlusSmsSender.SendMessage The SentlyPlusSmsSender class is defined in the attached solution. We have shown this line as commented as we want to explain the core Angular concepts. If you load the attached solution, this line is uncommented in the source and an actual SMS will be sent! By default, the API returns XML. For consumption of the API in Angular, we would like it to return JSON. To change the default to JSON, we make the following change to WebApiConfig.cs file located in the App_Start folder. public static class WebApiConfig { public static void Register(HttpConfiguration config) { config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); var appXmlType = config.Formatters.XmlFormatter. SupportedMediaTypes. FirstOrDefault( t => t.MediaType == "application/xml"); config.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType); } } We now have our backend REST Api which we can consume from Angular! 2. Creating the SmsView.html partial This simple partial will define two fields: the destination phone number (international format starting with a +) and the message. These fields will be bound to model.phoneNumber and model.message. We will also add a button that we shall hook up to sendMessage() in the controller. A list of all previously sent messages (bound to model.allMessages) will also be displayed below the form input. The following code shows the code for the partial: <!--­­ If model.errorMessage is defined, then render the error div -­­> <div class="alert alert-­danger alert-­dismissable" style="margin­-top: 30px;" ng­-show="model.errorMessage != undefined"> <button type="button" class="close" data­dismiss="alert" aria­hidden="true">&times;</button> <strong>Error!</strong> <br /> {{ model.errorMessage }} </div> <!--­­ The input fields bound to the model --­­> <div class="well" style="margin-­top: 30px;"> <table style="width: 100%;"> <tr> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Phone number (eg; +44 7778 609466)" ng­-model="model.phoneNumber" class="form-­control" style="width: 90%" onkeypress="return checkPhoneInput();" /> </td> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Message" ng­-model="model.message" class="form-­control" style="width: 90%" /> </td> <td style="text-­align: center;"> <button class="btn btn-­danger" ng-­click="sendMessage();" ng-­disabled="model.isAjaxInProgress" style="margin­right: 5px;">Send</button> <img src="/Content/ajax-­loader.gif" ng­-show="model.isAjaxInProgress" /> </td> </tr> </table> </div> <!--­­ The past messages ­­--> <div style="margin-­top: 30px;"> <!­­-- The following div is shown if there are no past messages --­­> <div ng­-show="model.allMessages.length == 0"> No messages have been sent yet! </div> <!--­­ The following div is shown if there are some past messages --­­> <div ng-­show="model.allMessages.length == 0"> <table style="width: 100%;" class="table table-­striped"> <tr> <td>Phone Number</td> <td>Message</td> <td></td> </tr> <!--­­ The ng-­repeat directive is line the repeater control in .NET, but as you can see this partial is pure HTML which is much cleaner --> <tr ng-­repeat="message in model.allMessages"> <td>{{ message.to }}</td> <td>{{ message.message }}</td> <td> <button class="btn btn-­danger" ng-­click="delete(message.smsId);" ng­-disabled="model.isAjaxInProgress">Delete</button> </td> </tr> </table> </div> </div> The above code is commented and should be self explanatory. Conditional rendering is achieved through using the ng-­show=”condition” attribute on various div tags. Input fields are bound to the model and the send button is bound to the sendMessage() function in the controller as through the ng­click=”sendMessage()” attribute defined on the button tag. While AJAX calls are taking place, the controller sets model.isAjaxInProgress to true. Based on this variable, buttons are disabled through the ng-­disabled directive which is added as an attribute to the buttons. The ng-­repeat directive added as an attribute to the tr tag causes the table row to be rendered multiple times much like an ASP.NET repeater. 3. Creating the SmsController controller The penultimate piece of our application is the controller which responds to events from our view and interacts with our MVC4 REST WebAPI. The following listing shows the code we need to add to /app/js/controllers.js. Note that controller definitions can be chained. Also note that this controller “asks for” the $http service. The $http service is a simple way in Angular to do AJAX. So far we have only encountered modules, controllers, views and directives in Angular. The $http is new entity in Angular called a service. More information on Angular services can be found at the following URL: http://docs.angularjs.org/guide/dev_guide.services.understanding_services. .controller('SmsController', ['$scope', '$http', function ($scope, $http) { //We define the model $scope.model = {}; //We define the allMessages array in the model //that will contain all the messages sent so far $scope.model.allMessages = []; //The error if any $scope.model.errorMessage = undefined; //We initially load data so set the isAjaxInProgress = true; $scope.model.isAjaxInProgress = true; //Load all the messages $http({ url: '/api/smsresource', method: "GET" }). success(function (data, status, headers, config) { this callback will be called asynchronously //when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { //called asynchronously if an error occurs //or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); $scope.delete = function (id) { //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource/' + id, method: "DELETE" }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } $scope.sendMessage = function () { $scope.model.errorMessage = undefined; var message = ''; if($scope.model.message != undefined) message = $scope.model.message.trim(); if ($scope.model.phoneNumber == undefined || $scope.model.phoneNumber == '' || $scope.model.phoneNumber.length < 10 || $scope.model.phoneNumber[0] != '+') { $scope.model.errorMessage = "You must enter a valid phone number in international format. Eg: +44 7778 609466"; return; } if (message.length == 0) { $scope.model.errorMessage = "You must specify a message!"; return; } //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource', method: "POST", data: { to: $scope.model.phoneNumber, message: $scope.model.message } }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status // We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } }]); We can see from the previous listing how the functions that are called from the view are defined in the controller. It should also be evident how easy it is to make AJAX calls to consume our MVC4 REST WebAPI. Now we are left with the final piece. We need to define a route that associates a particular path with the view we have defined and the controller we have defined. 4. Add a new route that loads the controller and the partial This is the easiest part of the puzzle. We simply define another route in the /app/js/app.js file: $routeProvider.when('/sms', { templateUrl: '/app/partials/smsview.html', controller: 'SmsController' }); Conclusion In this article we have seen how much of the server side functionality in the MVC4 framework can be moved to the browser thus delivering a snappy and fast user interface. We have seen how we can build client side HTML only views that avoid the messy syntax offered by server side Razor views. We have built a functioning app from the ground up. The significant advantage of this approach to building web apps is that the front end can be completely platform independent. Even though we used ASP.NET to create our REST API, we could just easily have used any other language such as Node.js, Ruby etc without changing a single line of our front end code. Angular is a rich framework and we have only touched on basic functionality required to create a SPA. For readers who wish to delve further into the Angular framework, we would recommend the following URL as a starting point: http://docs.angularjs.org/misc/started. To get started with the code for this project: Sign up for an account at http://plus.sent.ly (free) Add your phone number Go to the “My Identies Page” Note Down your Sender ID, Consumer Key and Consumer Secret Download the code for this article at: https://docs.google.com/file/d/0BzjEWqSE31yoZjZlV0d0R2Y3eW8/edit?usp=sharing Change the values of Sender Id, Consumer Key and Consumer Secret in the web.config file Run the project through Visual Studio!

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• Using HTML 5 SessionState to save rendered Page Content

  - by Rick Strahl

  HTML 5 SessionState and LocalStorage are very useful and super easy to use to manage client side state. For building rich client side or SPA style applications it's a vital feature to be able to cache user data as well as HTML content in order to swap pages in and out of the browser's DOM. What might not be so obvious is that you can also use the sessionState and localStorage objects even in classic server rendered HTML applications to provide caching features between pages. These APIs have been around for a long time and are supported by most relatively modern browsers and even all the way back to IE8, so you can use them safely in your Web applications. SessionState and LocalStorage are easy The APIs that make up sessionState and localStorage are very simple. Both object feature the same API interface which  is a simple, string based key value store that has getItem, setItem, removeitem, clear and  key methods. The objects are also pseudo array objects and so can be iterated like an array with  a length property and you have array indexers to set and get values with. Basic usage  for storing and retrieval looks like this (using sessionStorage, but the syntax is the same for localStorage - just switch the objects):// set var lastAccess = new Date().getTime(); if (sessionStorage) sessionStorage.setItem("myapp_time", lastAccess.toString()); // retrieve in another page or on a refresh var time = null; if (sessionStorage) time = sessionStorage.getItem("myapp_time"); if (time) time = new Date(time * 1); else time = new Date(); sessionState stores data that is browser session specific and that has a liftetime of the active browser session or window. Shut down the browser or tab and the storage goes away. localStorage uses the same API interface, but the lifetime of the data is permanently stored in the browsers storage area until deleted via code or by clearing out browser cookies (not the cache). Both sessionStorage and localStorage space is limited. The spec is ambiguous about this - supposedly sessionStorage should allow for unlimited size, but it appears that most WebKit browsers support only 2.5mb for either object. This means you have to be careful what you store especially since other applications might be running on the same domain and also use the storage mechanisms. That said 2.5mb worth of character data is quite a bit and would go a long way. The easiest way to get a feel for how sessionState and localStorage work is to look at a simple example. You can go check out the following example online in Plunker: http://plnkr.co/edit/0ICotzkoPjHaWa70GlRZ?p=preview which looks like this: Plunker is an online HTML/JavaScript editor that lets you write and run Javascript code and similar to JsFiddle, but a bit cleaner to work in IMHO (thanks to John Papa for turning me on to it). The sample has two text boxes with counts that update session/local storage every time you click the related button. The counts are 'cached' in Session and Local storage. The point of these examples is that both counters survive full page reloads, and the LocalStorage counter survives a complete browser shutdown and restart. Go ahead and try it out by clicking the Reload button after updating both counters and then shutting down the browser completely and going back to the same URL (with the same browser). What you should see is that reloads leave both counters intact at the counted values, while a browser restart will leave only the local storage counter intact. The code to deal with the SessionStorage (and LocalStorage not shown here) in the example is isolated into a couple of wrapper methods to simplify the code: function getSessionCount() { var count = 0; if (sessionStorage) { var count = sessionStorage.getItem("ss_count"); count = !count ? 0 : count * 1; } $("#txtSession").val(count); return count; } function setSessionCount(count) { if (sessionStorage) sessionStorage.setItem("ss_count", count.toString()); } These two functions essentially load and store a session counter value. The two key methods used here are: sessionStorage.getItem(key); sessionStorage.setItem(key,stringVal); Note that the value given to setItem and return by getItem has to be a string. If you pass another type you get an error. Don't let that limit you though - you can easily enough store JSON data in a variable so it's quite possible to pass complex objects and store them into a single sessionStorage value:var user = { name: "Rick", id="ricks", level=8 } sessionStorage.setItem("app_user",JSON.stringify(user)); to retrieve it:var user = sessionStorage.getItem("app_user"); if (user) user = JSON.parse(user); Simple! If you're using the Chrome Developer Tools (F12) you can also check out the session and local storage state on the Resource tab:   You can also use this tool to refresh or remove entries from storage. What we just looked at is a purely client side implementation where a couple of counters are stored. For rich client centric AJAX applications sessionStorage and localStorage provide a very nice and simple API to store application state while the application is running. But you can also use these storage mechanisms to manage server centric HTML applications when you combine server rendering with some JavaScript to perform client side data caching. You can both store some state information and data on the client (ie. store a JSON object and carry it forth between server rendered HTML requests) or you can use it for good old HTTP based caching where some rendered HTML is saved and then restored later. Let's look at the latter with a real life example. Why do I need Client-side Page Caching for Server Rendered HTML? I don't know about you, but in a lot of my existing server driven applications I have lists that display a fair amount of data. Typically these lists contain links to then drill down into more specific data either for viewing or editing. You can then click on a link and go off to a detail page that provides more concise content. So far so good. But now you're done with the detail page and need to get back to the list, so you click on a 'bread crumbs trail' or an application level 'back to list' button and… …you end up back at the top of the list - the scroll position, the current selection in some cases even filters conditions - all gone with the wind. You've left behind the state of the list and are starting from scratch in your browsing of the list from the top. Not cool! Sound familiar? This a pretty common scenario with server rendered HTML content where it's so common to display lists to drill into, only to lose state in the process of returning back to the original list. Look at just about any traditional forums application, or even StackOverFlow to see what I mean here. Scroll down a bit to look at a post or entry, drill in then use the bread crumbs or tab to go back… In some cases returning to the top of a list is not a big deal. On StackOverFlow that sort of works because content is turning around so quickly you probably want to actually look at the top posts. Not always though - if you're browsing through a list of search topics you're interested in and drill in there's no way back to that position. Essentially anytime you're actively browsing the items in the list, that's when state becomes important and if it's not handled the user experience can be really disrupting. Content Caching If you're building client centric SPA style applications this is a fairly easy to solve problem - you tend to render the list once and then update the page content to overlay the detail content, only hiding the list temporarily until it's used again later. It's relatively easy to accomplish this simply by hiding content on the page and later making it visible again. But if you use server rendered content, hanging on to all the detail like filters, selections and scroll position is not quite as easy. Or is it??? This is where sessionStorage comes in handy. What if we just save the rendered content of a previous page, and then restore it when we return to this page based on a special flag that tells us to use the cached version? Let's see how we can do this. A real World Use Case Recently my local ISP asked me to help out with updating an ancient classifieds application. They had a very busy, local classifieds app that was originally an ASP classic application. The old app was - wait for it: frames based - and even though I lobbied against it, the decision was made to keep the frames based layout to allow rapid browsing of the hundreds of posts that are made on a daily basis. The primary reason they wanted this was precisely for the ability to quickly browse content item by item. While I personally hate working with Frames, I have to admit that the UI actually works well with the frames layout as long as you're running on a large desktop screen. You can check out the frames based desktop site here: http://classifieds.gorge.net/ However when I rebuilt the app I also added a secondary view that doesn't use frames. The main reason for this of course was for mobile displays which work horribly with frames. So there's a somewhat mobile friendly interface to the interface, which ditches the frames and uses some responsive design tweaking for mobile capable operation: http://classifeds.gorge.net/mobile  (or browse the base url with your browser width under 800px)   Here's what the mobile, non-frames view looks like:   As you can see this means that the list of classifieds posts now is a list and there's a separate page for drilling down into the item. And of course… originally we ran into that usability issue I mentioned earlier where the browse, view detail, go back to the list cycle resulted in lost list state. Originally in mobile mode you scrolled through the list, found an item to look at and drilled in to display the item detail. Then you clicked back to the list and BAM - you've lost your place. Because there are so many items added on a daily basis the full list is never fully loaded, but rather there's a "Load Additional Listings"  entry at the button. Not only did we originally lose our place when coming back to the list, but any 'additionally loaded' items are no longer there because the list was now rendering  as if it was the first page hit. The additional listings, and any filters, the selection of an item all were lost. Major Suckage! Using Client SessionStorage to cache Server Rendered Content To work around this problem I decided to cache the rendered page content from the list in SessionStorage. Anytime the list renders or is updated with Load Additional Listings, the page HTML is cached and stored in Session Storage. Any back links from the detail page or the login or write entry forms then point back to the list page with a back=true query string parameter. If the server side sees this parameter it doesn't render the part of the page that is cached. Instead the client side code retrieves the data from the sessionState cache and simply inserts it into the page. It sounds pretty simple, and the overall the process is really easy, but there are a few gotchas that I'll discuss in a minute. But first let's look at the implementation. Let's start with the server side here because that'll give a quick idea of the doc structure. As I mentioned the server renders data from an ASP.NET MVC view. On the list page when returning to the list page from the display page (or a host of other pages) looks like this: https://classifieds.gorge.net/list?back=True The query string value is a flag, that indicates whether the server should render the HTML. Here's what the top level MVC Razor view for the list page looks like:@model MessageListViewModel @{ ViewBag.Title = "Classified Listing"; bool isBack = !string.IsNullOrEmpty(Request.QueryString["back"]); } <form method="post" action="@Url.Action("list")"> <div id="SizingContainer"> @if (!isBack) { @Html.Partial("List_CommandBar_Partial", Model) <div id="PostItemContainer" class="scrollbox" xstyle="-webkit-overflow-scrolling: touch;"> @Html.Partial("List_Items_Partial", Model) @if (Model.RequireLoadEntry) { <div class="postitem loadpostitems" style="padding: 15px;"> <div id="LoadProgress" class="smallprogressright"></div> <div class="control-progress"> Load additional listings... </div> </div> } </div> } </div> </form> As you can see the query string triggers a conditional block that if set is simply not rendered. The content inside of #SizingContainer basically holds  the entire page's HTML sans the headers and scripts, but including the filter options and menu at the top. In this case this makes good sense - in other situations the fact that the menu or filter options might be dynamically updated might make you only cache the list rather than essentially the entire page. In this particular instance all of the content works and produces the proper result as both the list along with any filter conditions in the form inputs are restored. Ok, let's move on to the client. On the client there are two page level functions that deal with saving and restoring state. Like the counter example I showed earlier, I like to wrap the logic to save and restore values from sessionState into a separate function because they are almost always used in several places.page.saveData = function(id) { if (!sessionStorage) return; var data = { id: id, scroll: $("#PostItemContainer").scrollTop(), html: $("#SizingContainer").html() }; sessionStorage.setItem("list_html",JSON.stringify(data)); }; page.restoreData = function() { if (!sessionStorage) return; var data = sessionStorage.getItem("list_html"); if (!data) return null; return JSON.parse(data); }; The data that is saved is an object which contains an ID which is the selected element when the user clicks and a scroll position. These two values are used to reset the scroll position when the data is used from the cache. Finally the html from the #SizingContainer element is stored, which makes for the bulk of the document's HTML. In this application the HTML captured could be a substantial bit of data. If you recall, I mentioned that the server side code renders a small chunk of data initially and then gets more data if the user reads through the first 50 or so items. The rest of the items retrieved can be rather sizable. Other than the JSON deserialization that's Ok. Since I'm using SessionStorage the storage space has no immediate limits. Next is the core logic to handle saving and restoring the page state. At first though this would seem pretty simple, and in some cases it might be, but as the following code demonstrates there are a few gotchas to watch out for. Here's the relevant code I use to save and restore:$( function() { … var isBack = getUrlEncodedKey("back", location.href); if (isBack) { // remove the back key from URL setUrlEncodedKey("back", "", location.href); var data = page.restoreData(); // restore from sessionState if (!data) { // no data - force redisplay of the server side default list window.location = "list"; return; } $("#SizingContainer").html(data.html); var el = $(".postitem[data-id=" + data.id + "]"); $(".postitem").removeClass("highlight"); el.addClass("highlight"); $("#PostItemContainer").scrollTop(data.scroll); setTimeout(function() { el.removeClass("highlight"); }, 2500); } else if (window.noFrames) page.saveData(null); // save when page loads $("#SizingContainer").on("click", ".postitem", function() { var id = $(this).attr("data-id"); if (!id) return true; if (window.noFrames) page.saveData(id); var contentFrame = window.parent.frames["Content"]; if (contentFrame) contentFrame.location.href = "show/" + id; else window.location.href = "show/" + id; return false; }); … The code starts out by checking for the back query string flag which triggers restoring from the client cache. If cached the cached data structure is read from sessionStorage. It's important here to check if data was returned. If the user had back=true on the querystring but there is no cached data, he likely bookmarked this page or otherwise shut down the browser and came back to this URL. In that case the server didn't render any detail and we have no cached data, so all we can do is redirect to the original default list view using window.location. If we continued the page would render no data - so make sure to always check the cache retrieval result. Always! If there is data the it's loaded and the data.html data is restored back into the document by simply injecting the HTML back into the document's #SizingContainer element:$("#SizingContainer").html(data.html); It's that simple and it's quite quick even with a fully loaded list of additional items and on a phone. The actual HTML data is stored to the cache on every page load initially and then again when the user clicks on an element to navigate to a particular listing. The former ensures that the client cache always has something in it, and the latter updates with additional information for the selected element. For the click handling I use a data-id attribute on the list item (.postitem) in the list and retrieve the id from that. That id is then used to navigate to the actual entry as well as storing that Id value in the saved cached data. The id is used to reset the selection by searching for the data-id value in the restored elements. The overall process of this save/restore process is pretty straight forward and it doesn't require a bunch of code, yet it yields a huge improvement in the usability of the site on mobile devices (or anybody who uses the non-frames view). Some things to watch out for As easy as it conceptually seems to simply store and retrieve cached content, you have to be quite aware what type of content you are caching. The code above is all that's specific to cache/restore cycle and it works, but it took a few tweaks to the rest of the script code and server code to make it all work. There were a few gotchas that weren't immediately obvious. Here are a few things to pay attention to: Event Handling Logic Timing of manipulating DOM events Inline Script Code Bookmarking to the Cache Url when no cache exists Do you have inline script code in your HTML? That script code isn't going to run if you restore from cache and simply assign or it may not run at the time you think it would normally in the DOM rendering cycle. JavaScript Event Hookups The biggest issue I ran into with this approach almost immediately is that originally I had various static event handlers hooked up to various UI elements that are now cached. If you have an event handler like:$("#btnSearch").click( function() {…}); that works fine when the page loads with server rendered HTML, but that code breaks when you now load the HTML from cache. Why? Because the elements you're trying to hook those events to may not actually be there - yet. Luckily there's an easy workaround for this by using deferred events. With jQuery you can use the .on() event handler instead:$("#SelectionContainer").on("click","#btnSearch", function() {…}); which monitors a parent element for the events and checks for the inner selector elements to handle events on. This effectively defers to runtime event binding, so as more items are added to the document bindings still work. For any cached content use deferred events. Timing of manipulating DOM Elements Along the same lines make sure that your DOM manipulation code follows the code that loads the cached content into the page so that you don't manipulate DOM elements that don't exist just yet. Ideally you'll want to check for the condition to restore cached content towards the top of your script code, but that can be tricky if you have components or other logic that might not all run in a straight line. Inline Script Code Here's another small problem I ran into: I use a DateTime Picker widget I built a while back that relies on the jQuery date time picker. I also created a helper function that allows keyboard date navigation into it that uses JavaScript logic. Because MVC's limited 'object model' the only way to embed widget content into the page is through inline script. This code broken when I inserted the cached HTML into the page because the script code was not available when the component actually got injected into the page. As the last bullet - it's a matter of timing. There's no good work around for this - in my case I pulled out the jQuery date picker and relied on native <input type="date" /> logic instead - a better choice these days anyway, especially since this view is meant to be primarily to serve mobile devices which actually support date input through the browser (unlike desktop browsers of which only WebKit seems to support it). Bookmarking Cached Urls When you cache HTML content you have to make a decision whether you cache on the client and also not render that same content on the server. In the Classifieds app I didn't render server side content so if the user comes to the page with back=True and there is no cached content I have to a have a Plan B. Typically this happens when somebody ends up bookmarking the back URL. The easiest and safest solution for this scenario is to ALWAYS check the cache result to make sure it exists and if not have a safe URL to go back to - in this case to the plain uncached list URL which amounts to effectively redirecting. This seems really obvious in hindsight, but it's easy to overlook and not see a problem until much later, when it's not obvious at all why the page is not rendering anything. Don't use <body> to replace Content Since we're practically replacing all the HTML in the page it may seem tempting to simply replace the HTML content of the <body> tag. Don't. The body tag usually contains key things that should stay in the page and be there when it loads. Specifically script tags and elements and possibly other embedded content. It's best to create a top level DOM element specifically as a placeholder container for your cached content and wrap just around the actual content you want to replace. In the app above the #SizingContainer is that container. Other Approaches The approach I've used for this application is kind of specific to the existing server rendered application we're running and so it's just one approach you can take with caching. However for server rendered content caching this is a pattern I've used in a few apps to retrofit some client caching into list displays. In this application I took the path of least resistance to the existing server rendering logic. Here are a few other ways that come to mind: Using Partial HTML Rendering via AJAXInstead of rendering the page initially on the server, the page would load empty and the client would render the UI by retrieving the respective HTML and embedding it into the page from a Partial View. This effectively makes the initial rendering and the cached rendering logic identical and removes the server having to decide whether this request needs to be rendered or not (ie. not checking for a back=true switch). All the logic related to caching is made on the client in this case. Using JSON Data and Client RenderingThe hardcore client option is to do the whole UI SPA style and pull data from the server and then use client rendering or databinding to pull the data down and render using templates or client side databinding with knockout/angular et al. As with the Partial Rendering approach the advantage is that there's no difference in the logic between pulling the data from cache or rendering from scratch other than the initial check for the cache request. Of course if the app is a  full on SPA app, then caching may not be required even - the list could just stay in memory and be hidden and reactivated. I'm sure there are a number of other ways this can be handled as well especially using  AJAX. AJAX rendering might simplify the logic, but it also complicates search engine optimization since there's no content loaded initially. So there are always tradeoffs and it's important to look at all angles before deciding on any sort of caching solution in general. State of the Session SessionState and LocalStorage are easy to use in client code and can be integrated even with server centric applications to provide nice caching features of content and data. In this post I've shown a very specific scenario of storing HTML content for the purpose of remembering list view data and state and making the browsing experience for lists a bit more friendly, especially if there's dynamically loaded content involved. If you haven't played with sessionStorage or localStorage I encourage you to give it a try. There's a lot of cool stuff that you can do with this beyond the specific scenario I've covered here… Resources Overview of localStorage (also applies to sessionStorage) Web Storage Compatibility Modernizr Test Suite© Rick Strahl, West Wind Technologies, 2005-2013Posted in JavaScript  HTML5  ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Mulitple full joins in Postgres is slow

  - by blast83

  I have a program to use the IMDB database and am having very slow performance on my query. It appears that it doesn't use my where condition until after it materializes everything. I looked around for hints to use but nothing seems to work. Here is my query: SELECT * FROM name as n1 FULL JOIN aka_name ON n1.id = aka_name.person_id FULL JOIN cast_info as t2 ON n1.id = t2.person_id FULL JOIN person_info as t3 ON n1.id = t3.person_id FULL JOIN char_name as t4 ON t2.person_role_id = t4.id FULL JOIN role_type as t5 ON t2.role_id = t5.id FULL JOIN title as t6 ON t2.movie_id = t6.id FULL JOIN aka_title as t7 ON t6.id = t7.movie_id FULL JOIN complete_cast as t8 ON t6.id = t8.movie_id FULL JOIN kind_type as t9 ON t6.kind_id = t9.id FULL JOIN movie_companies as t10 ON t6.id = t10.movie_id FULL JOIN movie_info as t11 ON t6.id = t11.movie_id FULL JOIN movie_info_idx as t19 ON t6.id = t19.movie_id FULL JOIN movie_keyword as t12 ON t6.id = t12.movie_id FULL JOIN movie_link as t13 ON t6.id = t13.linked_movie_id FULL JOIN link_type as t14 ON t13.link_type_id = t14.id FULL JOIN keyword as t15 ON t12.keyword_id = t15.id FULL JOIN company_name as t16 ON t10.company_id = t16.id FULL JOIN company_type as t17 ON t10.company_type_id = t17.id FULL JOIN comp_cast_type as t18 ON t8.status_id = t18.id WHERE n1.id = 2003 Very table is related to each other on the join via foreign-key constraints and have indexes for all the mentioned columns. The query plan details: "Hash Left Join (cost=5838187.01..13756845.07 rows=15579622 width=835) (actual time=146879.213..146891.861 rows=20 loops=1)" " Hash Cond: (t8.status_id = t18.id)" " -> Hash Left Join (cost=5838185.92..13542624.18 rows=15579622 width=822) (actual time=146879.199..146891.833 rows=20 loops=1)" " Hash Cond: (t10.company_type_id = t17.id)" " -> Hash Left Join (cost=5838184.83..13328403.29 rows=15579622 width=797) (actual time=146879.165..146891.781 rows=20 loops=1)" " Hash Cond: (t10.company_id = t16.id)" " -> Hash Left Join (cost=5828372.95..10061752.03 rows=15579622 width=755) (actual time=146426.483..146429.756 rows=20 loops=1)" " Hash Cond: (t12.keyword_id = t15.id)" " -> Hash Left Join (cost=5825164.23..6914088.45 rows=15579622 width=731) (actual time=146372.411..146372.529 rows=20 loops=1)" " Hash Cond: (t13.link_type_id = t14.id)" " -> Merge Left Join (cost=5825162.82..6699867.24 rows=15579622 width=715) (actual time=146372.366..146372.472 rows=20 loops=1)" " Merge Cond: (t6.id = t13.linked_movie_id)" " -> Merge Left Join (cost=5684009.29..6378956.77 rows=15579622 width=699) (actual time=144019.620..144019.711 rows=20 loops=1)" " Merge Cond: (t6.id = t12.movie_id)" " -> Merge Left Join (cost=5182403.90..5622400.75 rows=8502523 width=687) (actual time=136849.731..136849.809 rows=20 loops=1)" " Merge Cond: (t6.id = t19.movie_id)" " -> Merge Left Join (cost=4974472.00..5315778.48 rows=8502523 width=637) (actual time=134972.032..134972.099 rows=20 loops=1)" " Merge Cond: (t6.id = t11.movie_id)" " -> Merge Left Join (cost=1830064.81..2033131.89 rows=1341632 width=561) (actual time=63784.035..63784.062 rows=2 loops=1)" " Merge Cond: (t6.id = t10.movie_id)" " -> Nested Loop Left Join (cost=1417360.29..1594294.02 rows=1044480 width=521) (actual time=59279.246..59279.264 rows=1 loops=1)" " Join Filter: (t6.kind_id = t9.id)" " -> Merge Left Join (cost=1417359.22..1429787.34 rows=1044480 width=507) (actual time=59279.222..59279.224 rows=1 loops=1)" " Merge Cond: (t6.id = t8.movie_id)" " -> Merge Left Join (cost=1405731.84..1414378.65 rows=1044480 width=491) (actual time=59121.773..59121.775 rows=1 loops=1)" " Merge Cond: (t6.id = t7.movie_id)" " -> Sort (cost=1346206.04..1348817.24 rows=1044480 width=416) (actual time=58095.230..58095.231 rows=1 loops=1)" " Sort Key: t6.id" " Sort Method: quicksort Memory: 17kB" " -> Hash Left Join (cost=172406.29..456387.53 rows=1044480 width=416) (actual time=57969.371..58095.208 rows=1 loops=1)" " Hash Cond: (t2.movie_id = t6.id)" " -> Hash Left Join (cost=104700.38..256885.82 rows=1044480 width=358) (actual time=49981.493..50006.303 rows=1 loops=1)" " Hash Cond: (t2.role_id = t5.id)" " -> Hash Left Join (cost=104699.11..242522.95 rows=1044480 width=343) (actual time=49981.441..50006.250 rows=1 loops=1)" " Hash Cond: (t2.person_role_id = t4.id)" " -> Hash Left Join (cost=464.96..12283.95 rows=1044480 width=269) (actual time=0.071..0.087 rows=1 loops=1)" " Hash Cond: (n1.id = t3.person_id)" " -> Nested Loop Left Join (cost=0.00..49.39 rows=7680 width=160) (actual time=0.051..0.066 rows=1 loops=1)" " -> Nested Loop Left Join (cost=0.00..17.04 rows=3 width=119) (actual time=0.038..0.041 rows=1 loops=1)" " -> Index Scan using name_pkey on name n1 (cost=0.00..8.68 rows=1 width=39) (actual time=0.022..0.024 rows=1 loops=1)" " Index Cond: (id = 2003)" " -> Index Scan using aka_name_idx_person on aka_name (cost=0.00..8.34 rows=1 width=80) (actual time=0.010..0.010 rows=0 loops=1)" " Index Cond: ((aka_name.person_id = 2003) AND (n1.id = aka_name.person_id))" " -> Index Scan using cast_info_idx_pid on cast_info t2 (cost=0.00..10.77 rows=1 width=41) (actual time=0.011..0.020 rows=1 loops=1)" " Index Cond: ((t2.person_id = 2003) AND (n1.id = t2.person_id))" " -> Hash (cost=463.26..463.26 rows=136 width=109) (actual time=0.010..0.010 rows=0 loops=1)" " -> Index Scan using person_info_idx_pid on person_info t3 (cost=0.00..463.26 rows=136 width=109) (actual time=0.009..0.009 rows=0 loops=1)" " Index Cond: (person_id = 2003)" " -> Hash (cost=42697.62..42697.62 rows=2442362 width=74) (actual time=49305.872..49305.872 rows=2442362 loops=1)" " -> Seq Scan on char_name t4 (cost=0.00..42697.62 rows=2442362 width=74) (actual time=14.066..22775.087 rows=2442362 loops=1)" " -> Hash (cost=1.12..1.12 rows=12 width=15) (actual time=0.024..0.024 rows=12 loops=1)" " -> Seq Scan on role_type t5 (cost=0.00..1.12 rows=12 width=15) (actual time=0.012..0.014 rows=12 loops=1)" " -> Hash (cost=31134.07..31134.07 rows=1573507 width=58) (actual time=7841.225..7841.225 rows=1573507 loops=1)" " -> Seq Scan on title t6 (cost=0.00..31134.07 rows=1573507 width=58) (actual time=21.507..2799.443 rows=1573507 loops=1)" " -> Materialize (cost=59525.80..63203.88 rows=294246 width=75) (actual time=812.376..984.958 rows=192075 loops=1)" " -> Sort (cost=59525.80..60261.42 rows=294246 width=75) (actual time=812.363..922.452 rows=192075 loops=1)" " Sort Key: t7.movie_id" " Sort Method: external merge Disk: 24880kB" " -> Seq Scan on aka_title t7 (cost=0.00..6646.46 rows=294246 width=75) (actual time=24.652..164.822 rows=294246 loops=1)" " -> Materialize (cost=11627.38..12884.43 rows=100564 width=16) (actual time=123.819..149.086 rows=41907 loops=1)" " -> Sort (cost=11627.38..11878.79 rows=100564 width=16) (actual time=123.807..138.530 rows=41907 loops=1)" " Sort Key: t8.movie_id" " Sort Method: external merge Disk: 3136kB" " -> Seq Scan on complete_cast t8 (cost=0.00..1549.64 rows=100564 width=16) (actual time=0.013..10.744 rows=100564 loops=1)" " -> Materialize (cost=1.08..1.15 rows=7 width=14) (actual time=0.016..0.029 rows=7 loops=1)" " -> Seq Scan on kind_type t9 (cost=0.00..1.07 rows=7 width=14) (actual time=0.011..0.013 rows=7 loops=1)" " -> Materialize (cost=412704.52..437969.09 rows=2021166 width=40) (actual time=3420.356..4278.545 rows=1028995 loops=1)" " -> Sort (cost=412704.52..417757.43 rows=2021166 width=40) (actual time=3420.349..3953.483 rows=1028995 loops=1)" " Sort Key: t10.movie_id" " Sort Method: external merge Disk: 90960kB" " -> Seq Scan on movie_companies t10 (cost=0.00..35214.66 rows=2021166 width=40) (actual time=13.271..566.893 rows=2021166 loops=1)" " -> Materialize (cost=3144407.19..3269057.42 rows=9972019 width=76) (actual time=65485.672..70083.219 rows=5039009 loops=1)" " -> Sort (cost=3144407.19..3169337.23 rows=9972019 width=76) (actual time=65485.667..68385.550 rows=5038999 loops=1)" " Sort Key: t11.movie_id" " Sort Method: external merge Disk: 735512kB" " -> Seq Scan on movie_info t11 (cost=0.00..212815.19 rows=9972019 width=76) (actual time=15.750..15715.608 rows=9972019 loops=1)" " -> Materialize (cost=207925.01..219867.92 rows=955433 width=50) (actual time=1483.989..1785.636 rows=429401 loops=1)" " -> Sort (cost=207925.01..210313.59 rows=955433 width=50) (actual time=1483.983..1654.165 rows=429401 loops=1)" " Sort Key: t19.movie_id" " Sort Method: external merge Disk: 31720kB" " -> Seq Scan on movie_info_idx t19 (cost=0.00..15047.33 rows=955433 width=50) (actual time=7.284..221.597 rows=955433 loops=1)" " -> Materialize (cost=501605.39..537645.64 rows=2883220 width=12) (actual time=5823.040..6868.242 rows=1597396 loops=1)" " -> Sort (cost=501605.39..508813.44 rows=2883220 width=12) (actual time=5823.026..6477.517 rows=1597396 loops=1)" " Sort Key: t12.movie_id" " Sort Method: external merge Disk: 78888kB" " -> Seq Scan on movie_keyword t12 (cost=0.00..44417.20 rows=2883220 width=12) (actual time=11.672..839.498 rows=2883220 loops=1)" " -> Materialize (cost=141143.93..152995.81 rows=948150 width=16) (actual time=1916.356..2253.004 rows=478358 loops=1)" " -> Sort (cost=141143.93..143514.31 rows=948150 width=16) (actual time=1916.344..2125.698 rows=478358 loops=1)" " Sort Key: t13.linked_movie_id" " Sort Method: external merge Disk: 29632kB" " -> Seq Scan on movie_link t13 (cost=0.00..14607.50 rows=948150 width=16) (actual time=27.610..297.962 rows=948150 loops=1)" " -> Hash (cost=1.18..1.18 rows=18 width=16) (actual time=0.020..0.020 rows=18 loops=1)" " -> Seq Scan on link_type t14 (cost=0.00..1.18 rows=18 width=16) (actual time=0.010..0.012 rows=18 loops=1)" " -> Hash (cost=1537.10..1537.10 rows=91010 width=24) (actual time=54.055..54.055 rows=91010 loops=1)" " -> Seq Scan on keyword t15 (cost=0.00..1537.10 rows=91010 width=24) (actual time=0.006..14.703 rows=91010 loops=1)" " -> Hash (cost=4585.61..4585.61 rows=245461 width=42) (actual time=445.269..445.269 rows=245461 loops=1)" " -> Seq Scan on company_name t16 (cost=0.00..4585.61 rows=245461 width=42) (actual time=12.037..309.961 rows=245461 loops=1)" " -> Hash (cost=1.04..1.04 rows=4 width=25) (actual time=0.013..0.013 rows=4 loops=1)" " -> Seq Scan on company_type t17 (cost=0.00..1.04 rows=4 width=25) (actual time=0.009..0.010 rows=4 loops=1)" " -> Hash (cost=1.04..1.04 rows=4 width=13) (actual time=0.006..0.006 rows=4 loops=1)" " -> Seq Scan on comp_cast_type t18 (cost=0.00..1.04 rows=4 width=13) (actual time=0.002..0.003 rows=4 loops=1)" "Total runtime: 147055.016 ms" Is there anyway to force the name.id = 2003 before it tries to join all the tables together? As you can see, the end result is 4 tuples but it seems like it should be a fast join by using the available index after it limited it down with the name clause, although very complex.

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• Why do I get Detached Entity exception when upgrading Spring Boot 1.1.4 to 1.1.5

  - by mmeany

  On updating Spring Boot from 1.1.4 to 1.1.5 a simple web application started generating detached entity exceptions. Specifically, a post authentication inteceptor that bumped number of visits was causing the problem. A quick check of loaded dependencies showed that Spring Data has been updated from 1.6.1 to 1.6.2 and a further check of the change log shows a couple of issues relating to optimistic locking, version fields and JPA issues that have been fixed. Well I am using a version field and it starts out as Null following recommendation to not set in the specification. I have produced a very simple test scenario where I get detached entity exceptions if the version field starts as null or zero. If I create an entity with version 1 however then I do not get these exceptions. Is this expected behaviour or is there still something amiss? Below is the test scenario I have for this condition. In the scenario the service layer that has been annotated @Transactional. Each test case makes multiple calls to the service layer - the tests are working with detached entities as this is the scenario I am working with in the full blown application. The test case comprises four tests: Test 1 - versionNullCausesAnExceptionOnUpdate() In this test the version field in the detached object is Null. This is how I would usually create the object prior to passing to the service. This test fails with a Detached Entity exception. I would have expected this test to pass. If there is a flaw in the test then the rest of the scenario is probably moot. Test 2 - versionZeroCausesExceptionOnUpdate() In this test I have set the version to value Long(0L). This is an edge case test and included because I found reference to Zero values being used for version field in the Spring Data change log. This test fails with a Detached Entity exception. Of interest simply because the following two tests pass leaving this as an anomaly. Test 3 - versionOneDoesNotCausesExceptionOnUpdate() In this test the version field is set to value Long(1L). Not something I would usually do, but considering the notes in the Spring Data change log I decided to give it a go. This test passes. Would not usually set the version field, but this looks like a work-around until I figure out why the first test is failing. Test 4 - versionOneDoesNotCausesExceptionWithMultipleUpdates() Encouraged by the result of test 3 I pushed the scenario a step further and perform multiple updates on the entity that started life with a version of Long(1L). This test passes. Reinforcement that this may be a useable work-around. The entity: package com.mvmlabs.domain; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; import javax.persistence.Version; @Entity @Table(name="user_details") public class User { @Id @GeneratedValue(strategy=GenerationType.AUTO) private Long id; @Version private Long version; @Column(nullable = false, unique = true) private String username; @Column(nullable = false) private Integer numberOfVisits; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public Long getVersion() { return version; } public void setVersion(Long version) { this.version = version; } public Integer getNumberOfVisits() { return numberOfVisits == null ? 0 : numberOfVisits; } public void setNumberOfVisits(Integer numberOfVisits) { this.numberOfVisits = numberOfVisits; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } } The repository: package com.mvmlabs.dao; import org.springframework.data.repository.CrudRepository; import com.mvmlabs.domain.User; public interface UserDao extends CrudRepository<User, Long>{ } The service interface: package com.mvmlabs.service; import com.mvmlabs.domain.User; public interface UserService { User save(User user); User loadUser(Long id); User registerVisit(User user); } The service implementation: package com.mvmlabs.service; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Propagation; import org.springframework.transaction.annotation.Transactional; import org.springframework.transaction.support.TransactionSynchronizationManager; import com.mvmlabs.dao.UserDao; import com.mvmlabs.domain.User; @Service @Transactional(propagation=Propagation.REQUIRED, readOnly=false) public class UserServiceJpaImpl implements UserService { @Autowired private UserDao userDao; @Transactional(readOnly=true) @Override public User loadUser(Long id) { return userDao.findOne(id); } @Override public User registerVisit(User user) { user.setNumberOfVisits(user.getNumberOfVisits() + 1); return userDao.save(user); } @Override public User save(User user) { return userDao.save(user); } } The application class: package com.mvmlabs; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; @Configuration @ComponentScan @EnableAutoConfiguration public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } } The POM: <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.mvmlabs</groupId> <artifactId>jpa-issue</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>spring-boot-jpa-issue</name> <description>JPA Issue between spring boot 1.1.4 and 1.1.5</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.1.5.RELEASE</version> <relativePath /> <!-- lookup parent from repository --> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.hsqldb</groupId> <artifactId>hsqldb</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <start-class>com.mvmlabs.Application</start-class> <java.version>1.7</java.version> </properties> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project> The application properties: spring.jpa.hibernate.ddl-auto: create spring.jpa.hibernate.naming_strategy: org.hibernate.cfg.ImprovedNamingStrategy spring.jpa.database: HSQL spring.jpa.show-sql: true spring.datasource.url=jdbc:hsqldb:file:./target/testdb spring.datasource.username=sa spring.datasource.password= spring.datasource.driverClassName=org.hsqldb.jdbcDriver The test case: package com.mvmlabs; import org.junit.Assert; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.test.SpringApplicationConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import com.mvmlabs.domain.User; import com.mvmlabs.service.UserService; @RunWith(SpringJUnit4ClassRunner.class) @SpringApplicationConfiguration(classes = Application.class) public class ApplicationTests { @Autowired UserService userService; @Test public void versionNullCausesAnExceptionOnUpdate() throws Exception { User user = new User(); user.setUsername("Version Null"); user.setNumberOfVisits(0); user.setVersion(null); user = userService.save(user); user = userService.registerVisit(user); Assert.assertEquals(new Integer(1), user.getNumberOfVisits()); Assert.assertEquals(new Long(1L), user.getVersion()); } @Test public void versionZeroCausesExceptionOnUpdate() throws Exception { User user = new User(); user.setUsername("Version Zero"); user.setNumberOfVisits(0); user.setVersion(0L); user = userService.save(user); user = userService.registerVisit(user); Assert.assertEquals(new Integer(1), user.getNumberOfVisits()); Assert.assertEquals(new Long(1L), user.getVersion()); } @Test public void versionOneDoesNotCausesExceptionOnUpdate() throws Exception { User user = new User(); user.setUsername("Version One"); user.setNumberOfVisits(0); user.setVersion(1L); user = userService.save(user); user = userService.registerVisit(user); Assert.assertEquals(new Integer(1), user.getNumberOfVisits()); Assert.assertEquals(new Long(2L), user.getVersion()); } @Test public void versionOneDoesNotCausesExceptionWithMultipleUpdates() throws Exception { User user = new User(); user.setUsername("Version One Multiple"); user.setNumberOfVisits(0); user.setVersion(1L); user = userService.save(user); user = userService.registerVisit(user); user = userService.registerVisit(user); user = userService.registerVisit(user); Assert.assertEquals(new Integer(3), user.getNumberOfVisits()); Assert.assertEquals(new Long(4L), user.getVersion()); } } The first two tests fail with detached entity exception. The last two tests pass as expected. Now change Spring Boot version to 1.1.4 and rerun, all tests pass. Are my expectations wrong? Edit: This code saved to GitHub at https://github.com/mmeany/spring-boot-detached-entity-issue

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• getView only shows Flagged Backgrounds for drawn Views, It does not show Flagged Background when scroll to view more items on list

  - by Leoa

  I am trying to create a listview that receives a flagged list of items to indicate a status to the user. I have been able to create the flag display by using a yellow background (see image at bottom). In Theory, the flagged list can have many flagged items in it. However in my app, only the first three flagged backgrounds are shown. I believe this is because they are initially drawn to the screen. The Flagged background that are not drawn initially to the screen do not show. I'd like to know how to get the remaining flags to show in the list. ListView Recycling: The backgrounds in the listView are being recycled in getView(). This recycling goes from position 0 to position 9. I have flags that need to match at positions 13, 14 and so on. Those positions are not being displayed. listView.getCheckedItemPositions() for multiple selections: This method will not work in my case because the user will not selected the flags. The flags are coming from the server. setNotifyOnChange() and/or public virtual void SetNotifyOnChange (bool notifyOnChange): I'm not adding new data to the list, so I don't see how this method would work for my program. Does this method communicate to getview when it is recycling data? I was unable to find an answer to this in my research. public void registerDataSetObserver: This may be overkill for my problem, but is it possible to have an observer object that keeps track of the all the positions in my items list and in my flag list no matter if the view is recycled and match them on the screen? Code: package com.convention.notification.app; import java.util.Iterator; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.content.Context; import android.graphics.Color; import android.os.Bundle; import android.text.Html; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.TextView; public class NewsRowAdapter extends ArrayAdapter<Item> { private Activity activity; private List<Item> items; private Item objBean; private int row; private List<Integer> disable; View view ; int disableView; public NewsRowAdapter(Activity act, int resource, List<Item> arrayList, List<Integer> disableList) { super(act, resource, arrayList); this.activity = act; this.row = resource; this.items = arrayList; this.disable=disableList; System.out.println("results of delete list a:"+disable.toString()); } public int getCount() { return items.size(); } public Item getItem(int position) { return items.get(position); } public long getItemId(int position) { return position; } @Override public int getItemViewType(int position) { for(int k =0;k < disable.size();k++){ if(position==disable.get(k)){ //System.out.println( "is "+position+" value of disable "+disable.get(k)); disableView=disable.get(k); //AdapterView.getItemAtPosition(position); } } return position; } @Override public View getView(final int position, View convertView, ViewGroup parent) { View view = convertView; ViewHolder holder; if (view == null) { LayoutInflater inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE); view = inflater.inflate(row, null); getItemViewType(position); long id=getItemId(position); if(position==disableView){ view.setBackgroundColor(Color.YELLOW); System.out.println(" background set to yellow at position "+position +" disableView is at "+disableView); }else{ view.setBackgroundColor(Color.WHITE); System.out.println(" background set to white at position "+position +" disableView is at "+disableView); } //ViewHolder is a custom class that gets TextViews by name: tvName, tvCity, tvBDate, tvGender, tvAge; holder = new ViewHolder(); /* setTag Sets the tag associated with this view. A tag can be used to * mark a view in its hierarchy and does not have to be unique * within the hierarchy. Tags can also be used to store data within * a view without resorting to another data structure. */ view.setTag(holder); } else { //the Object stored in this view as a tag holder = (ViewHolder) view.getTag(); } if ((items == null) || ((position + 1) > items.size())) return view; objBean = items.get(position); holder.tv_event_name = (TextView) view.findViewById(R.id.tv_event_name); holder.tv_event_date = (TextView) view.findViewById(R.id.tv_event_date); holder.tv_event_start = (TextView) view.findViewById(R.id.tv_event_start); holder.tv_event_end = (TextView) view.findViewById(R.id.tv_event_end); holder.tv_event_location = (TextView) view.findViewById(R.id.tv_event_location); if (holder.tv_event_name != null && null != objBean.getName() && objBean.getName().trim().length() > 0) { holder.tv_event_name.setText(Html.fromHtml(objBean.getName())); } if (holder.tv_event_date != null && null != objBean.getDate() && objBean.getDate().trim().length() > 0) { holder.tv_event_date.setText(Html.fromHtml(objBean.getDate())); } if (holder.tv_event_start != null && null != objBean.getStartTime() && objBean.getStartTime().trim().length() > 0) { holder.tv_event_start.setText(Html.fromHtml(objBean.getStartTime())); } if (holder.tv_event_end != null && null != objBean.getEndTime() && objBean.getEndTime().trim().length() > 0) { holder.tv_event_end.setText(Html.fromHtml(objBean.getEndTime())); } if (holder.tv_event_location != null && null != objBean.getLocation () && objBean.getLocation ().trim().length() > 0) { holder.tv_event_location.setText(Html.fromHtml(objBean.getLocation ())); } return view; } public class ViewHolder { public TextView tv_event_name, tv_event_date, tv_event_start, tv_event_end, tv_event_location /*tv_event_delete_flag*/; } } Logcat: 06-12 20:54:12.058: I/System.out(493): item disalbed is at postion :0 06-12 20:54:12.058: I/System.out(493): item disalbed is at postion :4 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :5 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :13 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :14 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :17 06-12 20:54:12.069: I/System.out(493): results of delete list :[0, 4, 5, 13, 14, 17] 06-12 20:54:12.069: I/System.out(493): results of delete list a:[0, 4, 5, 13, 14, 17] 06-12 20:54:12.069: I/System.out(493): set adapaer to list view called; 06-12 20:54:12.128: I/System.out(493): background set to yellow at position 0 disableView is at 0 06-12 20:54:12.628: I/System.out(493): background set to white at position 1 disableView is at 0 06-12 20:54:12.678: I/System.out(493): background set to white at position 2 disableView is at 0 06-12 20:54:12.708: I/System.out(493): background set to white at position 3 disableView is at 0 06-12 20:54:12.738: I/System.out(493): background set to yellow at position 4 disableView is at 4 06-12 20:54:12.778: I/System.out(493): background set to yellow at position 5 disableView is at 5 06-12 20:54:12.808: I/System.out(493): background set to white at position 6 disableView is at 5 06-12 20:54:12.838: I/System.out(493): background set to white at position 7 disableView is at 5 This is a link to my first question a day ago: Change Background on a specific row based on a condition in Custom Adapter I appreciate your help!

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